The mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma represents a model for early evolution of sex chromosomes.

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Audrius Menkis

2008-03-01

Full Text Available We combined gene divergence data, classical genetics, and phylogenetics to study the evolution of the mating-type chromosome in the filamentous ascomycete Neurospora tetrasperma. In this species, a large non-recombining region of the mating-type chromosome is associated with a unique fungal life cycle where self-fertility is enforced by maintenance of a constant state of heterokaryosis. Sequence divergence between alleles of 35 genes from the two single mating-type component strains (i.e. the homokaryotic mat A or mat a-strains, derived from one N. tetrasperma heterokaryon (mat A+mat a, was analyzed. By this approach we were able to identify the boundaries and size of the non-recombining region, and reveal insight into the history of recombination cessation. The non-recombining region covers almost 7 Mbp, over 75% of the chromosome, and we hypothesize that the evolution of the mating-type chromosome in this lineage involved two successive events. The first event was contemporaneous with the split of N. tetrasperma from a common ancestor with its outcrossing relative N. crassa and suppressed recombination over at least 6.6 Mbp, and the second was confined to a smaller region in which recombination ceased more recently. In spite of the early origin of the first "evolutionary stratum", genealogies of five genes from strains belonging to an additional N. tetrasperma lineage indicate independent initiations of suppressed recombination in different phylogenetic lineages. This study highlights the shared features between the sex chromosomes found in the animal and plant kingdoms and the fungal mating-type chromosome, despite fungi having no separate sexes. As is often found in sex chromosomes of plants and animals, recombination suppression of the mating-type chromosome of N. tetrasperma involved more than one evolutionary event, covers the majority of the mating-type chromosome and is flanked by distal regions with obligate crossovers.

Gene genealogies indicates abundant gene conversions and independent evolutionary histories of the mating-type chromosomes in the evolutionary history of Neurospora tetrasperma

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Whittle Carrie A

2010-07-01

Full Text Available Abstract Background The self-fertile filamentous ascomycete Neurospora tetrasperma contains a large (~7 Mbp and young (mat chromosomes. The objective of the present study is to reveal the evolutionary history, including key genomic events, associated with the various regions of the mat chromosomes among ten strains representing all the nine known species (lineages contained within the N. tetrasperma species complex. Results Comparative analysis of sequence divergence among alleles of 24 mat-linked genes (mat A and mat a indicates that a large region of suppressed recombination exists within the mat chromosome for each of nine lineages of N. tetrasperma sensu latu. The recombinationally suppressed region varies in size and gene composition among lineages, and is flanked on both ends by normally recombining regions. Genealogical analyses among lineages reveals that eight gene conversion events have occurred between homologous mat A and mat a-linked alleles of genes located within the region of restricted recombination during the evolutionary history of N. tetrasperma. Conclusions We conclude that the region of suppressed recombination in the mat chromosomes has likely been subjected to independent contraction and/or expansion during the evolutionary history of the N. tetrasperma species complex. Furthermore, we infer that gene conversion events are likely a common phenomenon within this recombinationally suppressed genomic region. We argue that gene conversions might provide an efficient mechanism of adaptive editing of functional genes, including the removal of deleterious mutations, within the young recombinationally suppressed region of the mat chromosomes.

Accumulation of Elements in Salix and Other Species Used in Vegetation Filters with Focus on Wood Fuel Quality

Energy Technology Data Exchange (ETDEWEB)

Adler, Anneli

2007-07-01

Woody or herbaceous perennials used as vegetation filters for treatment of different types of wastes can be suitable for production of solid biofuels when their above ground harvestable biomass yield is sufficiently high and when biomass contains appropriate concentrations of minerals with regard to fuel combustion processes. The concentrations of nitrogen (N), potassium (K) and heavy metals (especially Zn and Cd) in fuel should be low and calcium (Ca) concentrations high to avoid technical problems and environmentally harmful emissions during combustion. Since soil supplementation with essential elements improves biomass yield, a conflict might arise between yield and quality aims. There are various possibilities to influence fuel quality during the growing phase of the life cycle of perennial biomass crops. This study assessed the suitability of two deciduous woody perennials (Salix and Populus) and two summer green herbaceous perennials (Phragmites and Urtica) for phytoremediation in terms of growth and nutrient allocation patterns. Salix and Populus proved suitable as vegetation filters when nutrients were available to plants in near-optimal proportions, but when unbalanced nutrient solutions (wastewater) were applied, stem biomass fraction was strongly reduced. Phragmites was more tolerant to wastewater treatment in terms of plant biomass production and nutrient allocation patterns, so if the N:P ratio of the wastewater is suboptimal, a vegetation filter using Phragmites could be considered. In further studies, a method was developed to determine the proportions of nutrient-rich bark in coppiced Salix, while heavy metal phytoextraction capacity was assessed in two Salix vegetation filters. The relevance of proportion of bark on wood fuel quality and element removal from vegetation filters was also investigated. The concentrations of the elements studied in harvestable Salix shoot biomass were higher, meaning lower wood fuel quality, in plantations where

Nitrogen-controlled intra- and interspecific competition between Populus purdomii and Salix rehderiana drive primary succession in the Gongga Mountain glacier retreat area.

Science.gov (United States)

Song, Mengya; Yu, Lei; Jiang, Yonglei; Lei, Yanbao; Korpelainen, Helena; Niinemets, Ülo; Li, Chunyang

2017-06-01

In this study, intra- and interspecific competition were investigated in early successional Salix rehderiana Schneider and later-appearing Populus purdomii Rehder under non-fertilized (control) and nitrogen (N)-fertilized conditions in the Hailuogou glacier retreat area. Our aim was to discover whether N is a key factor in plant-plant competition and whether N drives the primary succession process in a glacier retreat area. We analyzed differences in responses to intra- and interspecific competition and N fertilization between P. purdomii and S. rehderiana, including parameters such as biomass accumulation, nutrient absorption, non-structural carbohydrates, photosynthetic capacity, hydrolysable amino acids and leaf ultrastructure. In the control treatments, S. rehderiana individuals subjected to interspecific competition benefited from the presence of P. purdomii plants, as indicated by higher levels of biomass accumulation, photosynthetic capacity, N absorption, amino acid contents and photosynthetic N-use efficiency. However, in the N-fertilized treatments, P. purdomii individuals exposed to interspecific competition benefited from the presence of S. rehderiana plants, as shown by a higher growth rate, enhanced carbon gain capacity, greater amino acid contents, and elevated water-use efficiency, whereas the growth of S. rehderiana was significantly reduced. Our results demonstrate that N plays a pivotal role in determining the asymmetric competition pattern among Salicaceae species during primary succession. We argue that the interactive effects of plant-plant competition and N availability are key mechanisms that drive primary succession in the Gongga Mountain glacier retreat area. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Untitled

Indian Academy of Sciences (India)

in the Kulu Valley and Simla Hills in the Punjab and of “walnut and alder in the Darjeeling Himalayas and of oak in the Kumaon Himalayas'. (Beeson, 1941). In addition to these plants Beeson (1941) also found it on. Salix tetrasperma, Trema amboinensis and mentions its occurrence on Parlo- wina tomentosa in Japan.

Declines in populations of Salix caprea L.during forest regeneration after strong herbivore pressure

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Janusz B. Faliński

2014-01-01

Full Text Available Communities of broadleaved forest subject to strong pressure from large herbivores underwent degeneration. The relief of this pressure led to regeneration of the community, in which an important role was played by the sallow Salix caprea and other light-seeded pioneer species of tree (Populus tremula, Betula pendula and B. pubescens. Regeneration involving Salix caprea proceeded following the conservatorial protection of the degenerate stands in a reserve and later in Białowieża National Park. The emergence and development of the population of Salix caprea proceeded following the invasion of spruce, which coincided with the period of enhanced animal pressure on broadleaved forest. Salix caprea filled all the gaps in the tree stand arising as a result of the destruction of trees and undergrowth by herbivores (in the years 1892-1915. It also appeared en masse on old, at that time unforested, clearings and felled areas. In these places, Salix caprea created very abundant populations, with particular trees being in good condition, with a habit typical of forest trees and attaining considerable heights. The majority of trees were 50-60 years old at the time of death, although individuals reached 74 years of age. The process of extinction of the sallow population - observed over 19 years on permanent plots and fixed trees - proceeded very quickly, especially in the first decade of observation. It led to the almost complete disappearance of sallow for the forest communities of Białowieża National Park. The death of individual trees is preceded by impairment of their health and reduced annual increments in the 4-9 last years of life. The extinction of the population is associated with the loss of its primary phenological differentiation and with a change in the sex structure of the population from a prevalence of female trees to a near even distribution of the two sexes. The development of the populations of permanent constituents of the forest

Cadmium in Salix. A study to show the capacity of Salix to remove cadmium from farmland

International Nuclear Information System (INIS)

Oestman, G.

1994-01-01

The aim of this report has been to show the ability of Salix to take up cadmium and how the uptake varies between different types of soil. The information that the results are based on has been obtained from analyses of soil and Salix. The samples were taken at five sites in the district around Lake Maelaren. Two or three stands were taken at each place. The factors studied were the pH, the organic matter content, and the concentration of cadmium in the soil. Salix has a good ability, relative to other crops, to remove cadmium from arable land. The cadmium uptake is 35 times higher with Salix than with straw or energy grass. Salix uptake of cadmium varies between 3 and 14% of the cadmium content in the soil that is accessible to plants. The present annual increase of cadmium in arable land is 1 g/ha, whereas the removal in a Salix plantation is 21 g Cd/ha, yr at an annual growth of 10 tonnes DM. If the Cd uptake is the same each year, then a total of 420 g Cd/ha is removed when Salix is grown over a 20-year period. This is a very large part of the topsoil's total cadmium content, which is 550 g/ha on average in Sweden. The investigation reveals no clear relationship between the Cd concentration in Salix and the concentration of Cd in the soil, the organic matter content or the pH. 22 refs, 4 figs, 2 tabs

Phytoextraction of risk elements by willow and poplar trees.

Science.gov (United States)

Kacálková, Lada; Tlustoš, Pavel; Száková, Jiřina

2015-01-01

To characterize the phytoextraction efficiency of two clones of willow trees (Salix x smithiana Willd., Salix rubens) and two clones of poplar trees (Populus nigra x maximowiczii, Populus nigra Wolterson) were planted in contaminated soil (0.4-2.0 mg Cd.kg(-1), 78-313 mg Zn.kg(-1), 21.3-118 mg Cu.kg(-1)). Field experiment was carried out in Czech Republic. The study investigated their ability to accumulate heavy metals (Cd, Zn, and Cu) in harvestable plant parts. The poplars produced higher amount of biomass than willows. Both Salix clones accumulated higher amount of Cd, Zn and Cu in their biomass (maximum 6.8 mg Cd.kg(-1), 909 mg Zn.kg(-1), and 17.7 mg Cu.kg(-1)) compared to Populus clones (maximum 2.06 mg Cd.kg(-1), 463 mg Zn.kg(-1), and 11.8 mg Cu.kg(-1)). There were no significant differences between clones of individual species. BCs for Cd and Zn were greater than 1 (the highest in willow leaves). BCs values of Cu were very low. These results indicate that Salix is more suitable plant for phytoextraction of Cd and Zn than Populus. The Cu phytoextraction potential of Salix and Populus trees was not confirmed in this experiment due to low soil availability of this element.

Comparative Anti-Diabetic Evaluation of Different Parts of Himalrandia tetrasperma in Alloxan Induced Diabetic in Mice

International Nuclear Information System (INIS)

Ajaib, M.

2016-01-01

The present experiments were designed to investigate the acute effects of methanolic extracts of various parts of H. tetrasperma in diabetic mice. The basic phyto-chemical study showed the occurrence of alkaloids, saponins, flavonoids and tannins as main phyto-constituents in the methanolic extract. Diabetes was induced experimentally in mice by intra peritoneally injecting alloxan (150 mg/kg i.p.). In acute study, methanolic H. tetrasperma extracts of various parts of plant were evaluated for anti-diabetic potential in alloxan induced diabetic mice. Extracts of leaves, bark and seeds (250 mg/kg, i.p) and metformin (250 mg/kg i.p) were given intra peritoneal in alloxan treated diabetic mice and blood glucose levels were measured at 0, 360 and 24 h. There was significant lowering of blood glucose level at 1 h after treatment, in diabetic mice treated with methanolic extracts of bark (182.3 ± 3.6 mg/dL), leaves (178.5 ± 1.2 mg/dL) and seeds (156.3 ± 11.3 mg/dL) when compared with control diabetic group (280 ± 7.92 mg/dL). Highly significant results were also obtained at 24 h after treatment with methanolic extracts of bark (187.67 ±1.2 mg/dL), leaves (170.66 ± 2.3 mg/dL) and seeds (142 ± 8.7 mg/dL) when compared with control diabetic group (257.7 ± 6.7 mg/dL). It is concluded that methanolic extract of all parts possess significant anti-diabetic activity which is due to the presence of phytochemicals, i.e. alkaloids, flavonoids, phenols, saponins, tannins and it can be further evaluated for the mechanism involved. (author)

Patch test with ether extracts in salicaceae allergy

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Sawhney M

2002-01-01

Full Text Available A total of 23 cases suggestive of airborne contact dermatitis were patch tested with ether extracts of flowers and leaves of populus sp. and salix sp. in a study conducted in Ladakh at an altitude of 3445 meters above sea level. Overall positivity was found in 12 (52.17%, with populus sp. alone in 7 (30. 43%, salix sp. alone in 4 17.39% and to both in one (8.33%.

Effects of phytoextraction on heavy metal concentrations and pH of pore-water of biosolids determined using an in situ sampling technique

Energy Technology Data Exchange (ETDEWEB)

Huynh, T.T. [Applied Ecology Research Group, School of Botany, University of Melbourne, Parkville, VIC 3010 (Australia)], E-mail: t.huynh11@pgrad.unimelb.edu.au; Laidlaw, W.S. [Applied Ecology Research Group, School of Botany, University of Melbourne, Parkville, VIC 3010 (Australia); Singh, B. [Faculty of Agriculture, Food and Natural Resources, University of Sydney, Sydney, NSW 2006 (Australia); Gregory, D. [Research and Technology Division, Melbourne Water, Melbourne, VIC 3001 (Australia); Baker, A.J.M. [Applied Ecology Research Group, School of Botany, University of Melbourne, Parkville, VIC 3010 (Australia)

2008-12-15

Heavy metal concentrations and pH of pore-water in contaminated substrates are important factors in controlling metal uptake by plants. We investigated the effects of phytoextraction on these properties in the solution phase of biosolids and diluted biosolids in a 12-month phytoextraction column experiment. Phytoextraction using Salix and Populus spp. temporarily decreased pore-water pH of the substrates over the experimental period followed by a return to initial pH conditions. Salix x reichardtii and Populus balsamifera effectively extracted Ni, Zn and Cd and actively mobilized these metals from the solid to the solution phase. S. x reichardtii had the stronger effect on mobilization of metals due to its larger root system. Phytoextraction did not affect Cu in the solution phase of the biosolids. Heavy metals were leached down to lower depths of the columns during the phytoextraction process. - Salix x reichardtii and Populus balsamifera extracted Ni, Zn and Cd and mobilized these metals in biosolids during phytoextraction.

Effects of phytoextraction on heavy metal concentrations and pH of pore-water of biosolids determined using an in situ sampling technique

International Nuclear Information System (INIS)

Huynh, T.T.; Laidlaw, W.S.; Singh, B.; Gregory, D.; Baker, A.J.M.

2008-01-01

Heavy metal concentrations and pH of pore-water in contaminated substrates are important factors in controlling metal uptake by plants. We investigated the effects of phytoextraction on these properties in the solution phase of biosolids and diluted biosolids in a 12-month phytoextraction column experiment. Phytoextraction using Salix and Populus spp. temporarily decreased pore-water pH of the substrates over the experimental period followed by a return to initial pH conditions. Salix x reichardtii and Populus balsamifera effectively extracted Ni, Zn and Cd and actively mobilized these metals from the solid to the solution phase. S. x reichardtii had the stronger effect on mobilization of metals due to its larger root system. Phytoextraction did not affect Cu in the solution phase of the biosolids. Heavy metals were leached down to lower depths of the columns during the phytoextraction process. - Salix x reichardtii and Populus balsamifera extracted Ni, Zn and Cd and mobilized these metals in biosolids during phytoextraction

RESISTÊNCIA DO VIMEIRO, Salix spp. (Salicaceae, À PRAGAS E DOENÇAS

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Pedro Boff

2007-03-01

Full Text Available Este trabalho teve o objetivo de avaliar a reação de resistência a pragas e doenças de clones locais do vimeiro comum, Salix x rubens, e de espécies introduzidas da Argentina, Chile, Alemanha e França. Três experimentos foram conduzidos em campo no ciclo de cultivo 2003/2004, em diferentes ecossistemas do Planalto Serrano Catarinense. As avaliações de resistência constaram da estimativa de danos causados pelos insetos e da severidade de doenças foliares. No conjunto de todas as avaliações, os acessos – genótipos introduzidos – EEL_10 (Salix nigra, EEL_08 (Salix sp., EEL_02 (Salix x rubens, EEL_13 (Salix sp., EEL_09 (Salix alba, e EEL_20 (Salix sp. foram os mais resistentes ao ataque de pragas e doenças. Dada a reação diferenciada dos acessos quanto ao ataque de doenças e pragas, as próximas ações de pesquisa devem proceder aos testes de artesanato para verificar a sua adequação à demanda para confecção de peças finas.

Distribution of P, K, Ca, Mg, Cd, Cu, Fe, Mn, Pb and Zn in wood and bark age classes of willows and poplars used for phytoextraction on soils contaminated by risk elements.

Science.gov (United States)

Zárubová, Pavla; Hejcman, Michal; Vondráčková, Stanislava; Mrnka, Libor; Száková, Jiřina; Tlustoš, Pavel

2015-12-01

Fast-growing clones of Salix and Populus have been studied for remediation of soils contaminated by risk elements (RE) using short-rotation coppice plantations. Our aim was to assess biomass yield and distributions of elements in wood and bark of highly productive willow (S1--[Salix schwerinii × Salix viminalis] × S. viminalis, S2--Salix × smithiana clone S-218) and poplar (P1--Populus maximowiczii × Populus nigra, P2--P. nigra) clones with respect to aging. The field experiment was established in April 2008 on moderately Cd-, Pb- and Zn- contaminated soil. Shoots were harvested after four seasons (February 2012) and separated into annual classes of wood and bark. All tested clones grew on contaminated soils, with highest biomass production and lowest mortality exhibited by P1 and S2. Concentrations of elements, with exception of Ca and Pb, decreased with age and were higher in bark than in wood. The Salix clones were characterised by higher removal of Cd, Mn and Zn compared to the Populus clones. Despite generally higher RE content in young shoots, partly due to lower wood/bark ratios and higher RE concentrations in bark, the overall removal of RE was higher in older wood classes due to higher biomass yield. Thus, longer rotations seem to be more effective when phytoextraction strategy is considered. Of the four selected clones, S1 exhibited the best removal of Cd and Zn and is a good candidate for phytoextraction.

Developing woody crops for the enhancement of ecosystem services under changing climates in the north central United States

Science.gov (United States)

Ronald S. Zalesny; William L. Headlee

2015-01-01

Short rotation woody crops belonging to the genera Populus L., Salix L., Pinus L., and Eucalyptus LHer. have provided broad economic and ecological benefits throughout the world, including afforestation and reforestation along urban to rural gradients. Within the genus Populus...

Resistência do vimeiro, Salix spp. (Salicaceae, à pragas e doenças.

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Jamille Casa

2010-08-01

Full Text Available Este trabalho teve o objetivo de avaliar a reação de resistência a pragas e doenças de clones locais do vimeiro comum, Salix x rubens, e de espécies introduzidas da Argentina, Chile, Alemanha e França. Três experimentos foram conduzidos em campo no ciclo de cultivo 2003/2004, em diferentes ecossistemas do Planalto Serrano Catarinense. As avaliações de resistência constaram da estimativa de danos causados pelos insetos e da severidade de doenças foliares. No conjunto de todas as avaliações, os acessos - genótipos introduzidos - EEL_10 (Salix nigra, EEL_08 (Salix sp., EEL_02 (Salix x rubens, EEL_13 (Salix sp., EEL_09 (Salix alba, e EEL_20 (Salix sp. foram os mais resistentes ao ataque de pragas e doenças. Dada a reação diferenciada dos acessos quanto ao ataque de doenças e pragas, as próximas ações de pesquisa devem proceder aos testes de artesanato para verificar a sua adequação à demanda para confecção de peças finas.

Boron accumulation and toxicity in hybrid poplar (Populus nigra × euramericana).

Science.gov (United States)

Rees, Rainer; Robinson, Brett H; Menon, Manoj; Lehmann, Eberhard; Günthardt-Goerg, Madeleine S; Schulin, Rainer

2011-12-15

Poplars accumulate high B concentrations and are thus used for the phytomanagement of B contaminated soils. Here, we performed pot experiments in which Populus nigra × euramericana were grown on a substrate with B concentrations ranging from 13 to 280 mg kg(-1) as H(3)BO(3). Salix viminalis, Brassica juncea, and Lupinus albus were grown under some growing conditions for comparison. Poplar growth was unaffected at soil B treatment levels up to 93 mg kg(-1). Growth was progressively reduced at levels of 168 and 280 mg kg(-1). None of the other species survived at these substrate B levels. At leaf B concentrations toxicity. Neutron radiography revealed that chlorotic leaf tissues had B concentrations of 1000-2000 mg kg(-1), while necrotic tissues had >2000 mg kg(-1). Average B concentrations of up to 3500 mg kg(-1) were found in leaves, while spots within leaves had concentrations >7000 mg kg(-1), showing that B accumulation in leaf tissue continued even after the onset of necrosis. The B accumulation ability of P. nigra × euramericana is associated with B hypertolerance in the living tissue and storage of B in dead leaf tissue.

Assessment of Salix spp. pollen availability to insects based on aerobiological investigations

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Elżbieta Weryszko-Chmielewska

2017-06-01

Full Text Available Pollen and nectar produced by flowers of species from the genus Salix are an important source of food for various insect groups in early spring. Most willows are entomophilous species; however, substantial amounts of airborne Salix pollen can be noted. The aim of the study was to evaluate the content of pollen of this taxon in the air of Lublin (central-east Poland in 2001–2016 and to identify the period of its greatest availability to insects. In 2015, we compared the course of the Salix pollen season in Lublin (51°14'37" N; 22°32'25" E and in the Roztoczański National Park (50°34'57" N; 23°04'24" E, Poland. We found that the date of the pollen season onset fluctuated greatly between March 16 and April 17. The greatest availability of Salix pollen to insects was noted from the end of the first 10-day-period of April to the first 10-day-period of May. The mean annual sum of airborne Salix pollen grains was 833. In Lublin, Salix pollen accounted for ca. 1.25% of the total airborne pollen content of different plant taxa. The investigations have demonstrated a 2-year cycle of Salix pollen abundance. The comparison of the pollen seasons in Lublin and in the Roztoczański National Park indicates that considerably greater amounts of pollen occur in the urban area than in the air of the Roztoczański National Park.

Novel Field Data on Phytoextraction: Pre-Cultivation With Salix Reduces Cadmium in Wheat Grains.

Science.gov (United States)

Greger, Maria; Landberg, Tommy

2015-01-01

Cadmium (Cd) is a health hazard, and up to 43% of human Cd intake comes from wheat products, since Cd accumulates in wheat grains. Salix spp. are high-accumulators of Cd and is suggested for Cd phytoextraction from agricultural soils. We demonstrate, in field, that Salix viminalis can remove Cd from agricultural soils and thereby reduce Cd accumulation in grains of wheat subsequently grown in a Salix-treated field. Four years of Salix cultivation reduce Cd concentration in the soil by up to 27% and in grains of the post-cultivated wheat by up to 33%. The higher the plant density of the Salix, the greater the Cd removal from the soil and the lower the Cd concentration in the grains of post-cultivated wheat, the Cd reduction remaining stable several years after Salix cultivation. The effect occurred in both sandy and clayey soil and in winter and spring bread wheat cultivars. Already one year of Salix cultivation significantly decrease Cd in post grown wheat grains. With this field experiment we have demonstrated that phytoextraction can reduce accumulation of a pollutant in post-cultivated wheat and that phytoextraction has no other observed effect on post-cultivated crops than reduced uptake of the removed pollutant.

Salix: A viable option for phytoremediation

African Journals Online (AJOL)

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Many animals depend on willows for food. (mostly leaf ... tolerant to deposition and resistant to moderate salinity .... mechanism may enable stabilization of toxic metals ... 'Phytoremediation of Lead, Nickel, and Copper by Salix acmophylla.

Preliminary tests for Salix sp. tolerance to heavy metals (Cd, Ni, Pb)

Science.gov (United States)

Corneanu, Mihaela; Hernea, Cornelia; Butnariu, Monica; Corneanu, Gabriel; Sărac, Ioan; Hollerbach, Wilhelm; Neţoiu, Constantin; Petcov, Andreea Adriana

2014-05-01

The species of Salix genus constitute potential sources of germplasm in the prevention of the environment degradation, and offer remedy for about two third from the all degradation types. The majority of the willow species, present a good adaptation to hypoxic conditions, feature which suggest that they manifest a preference for mineral nutrition in comparison with organic one. Thus, many of willow species can be developed on soils with a big amount of minerals and/or radionuclides, being both phytoremediatory species, as well as pioneer ones, contributing to the restoration of soil. Thus, the willow species, posses the capacity for development in degraded areas, natural or anthropic, as swamps, abandoning crops areas, sandy dune, riparian sandy areas, gravels, a.o. In this paper are present some laboratory comparative tests of heavy metals tolerance on four Salix sp. genotypes: clone 202 (Salix alba), hybrid 892 (Salix alba), Inger (Salix viminalis) and Gudrun (Salix viminalis). The genotypes of Salix alba are native from Romania, produced in the Forest Research and Management Institute Bucharest, while the genotypes of Salix viminalis are native from Sweden, but the plant material was produced under license in Romania by REBINA Agrar SRL. As plant material were used one-year-old cuttings (5-10 cm long), with 2-6 buds each. Per genotype, per heavy metal and each of three concentration five replication were used. There were ten experimental variants for each genotype: three concentrations for each of the heavy metals; concentrations selected, in the accordance SR ISO 11269-2/March 1999 and Control (tap water). The cuttings were maintained in metalic solutions for 15 days. In the days 7th and 15th, were performed biometrical observations on: the roots number and length, the shoots number and length, the leaves number/shoot, viability of the shoots. At the end of the experiment the content in heavy metals was determined in roots and shoots (by atomic absorption

Wood property variation in Populus

Science.gov (United States)

Dean W. Einspahr; Miles K. Benson; John R. Peckham

1968-01-01

The use of bigtooth aspen (Populus grandidentata Michx.), quaking aspen (P. tremuloides Michx.), and cottonwood (P. deltoides Bartr.) by the pulp and paper industry has increased greatly during the past decade. This expanded use has stimulated research on the genetic improvement of Populus. For the past 12 years...

Evaluation of salix farmers experiences and attitudes to growing; Utvaerdering av salixodlares erfarenheter och attityder till odling

Energy Technology Data Exchange (ETDEWEB)

Paulrud, Susanne; Roennbaeck, Marie (Swedish National Testing and Research Inst., Boraas (Sweden)); Gunnarsson, Carina; Olsson, Johanna (Swedish Inst. of Agricultural and Environmental Engineering, Uppsala (Sweden))

2010-11-15

Approximately 16 000 hectares of salix (willow) were planted in Sweden in the early 1990s, driven by subsidies and optimistic market expectations. Today the salix plantations have decreased to approximately 12000 hectares. In this study 29 salix farmers and four entrepreneurs that work with salix harvest were interviewed to find out more about their attitudes to, and experiences of growing salix. Most of the farmers interviewed were not satisfied with their salix plantation. The reasons given were the low profitability and problems with the harvest systems. Key reasons for the low profitability are cited as: old plantations that are planted on poor soil; lack of fertilization; an ineffective organization to taking care of the harvest and to sell the salix chips; and a low price for the salix chips. In addition the system for harvesting needs to be more flexible and there is a need for machine systems adapted for harvest of smaller fields

Interaction in Short rotation coppice willow, Salix viminalis genotype mixtures

Energy Technology Data Exchange (ETDEWEB)

Begley, D. [Department of Biological Sciences, Queen' s University Belfast, Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom); McCracken, A.R. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)]|[Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Dawson, W.M. [Northern Ireland Horticulture and Plant Breeding Station, Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, Loughgall, Co., Armagh BT61 8JB, Northern Ireland (United Kingdom); Watson, S. [Applied Plant Science and Biometrics Division, Agri-Food and Biosciences Institute, 18A Newforge Lane, Belfast BT9 5PX, Northern Ireland (United Kingdom)

2009-02-15

Seven straight Salix viminalis genotypes with different levels of rust (Melampsora epitea) susceptibility were grown as mono-plots as well as being incorporated into a range of mixtures. Two 3-year harvests (2003 and 2006) were taken. Disease progress was followed on each of the individual genotypes throughout each growing season 2001-2006. In 2003 there were small but significant yield increases from the mixtures compared to the yield of individual components grown as mono-plots. These differences were not evident at the second harvest in 2006. No consistent effect of mixtures on reducing rust on the most susceptible genotype, Salix viminalis '77082' were observed. In some years, e.g. 2003, at certain times during the growing season, significant reductions were observed on Salix viminalis '77082' in certain 3-way mixtures compared to mono-plots. These, however, were not repeated consistently in subsequent years. It was concluded that the current commercial practice in many parts of Europe of planting mixtures as a disease control strategy will only be effective if there is sufficient genetic diversity between the Salix genotypes incorporated into the mixture. (author)

Distribution and trends of mercury in deciduous tree cores

International Nuclear Information System (INIS)

Siwik, Eden I.H.; Campbell, Linda M.; Mierle, Gregory

2010-01-01

The distribution of total mercury (THg) within common deciduous trees and the applicability of tree cores as biomonitors of historical environmental THg trends were assessed for both contaminated and reference sites around Kingston, Ontario. Samples were collected from Acer spp., Quercus spp. Populus spp. and Salix spp. Bark and wood THg concentrations were found to be highly correlated whereas soil and wood THg concentrations were not. There were no temporal relationships for THg in dated tree rings corresponding with any other known environmental Hg trends. The shoreline speciess, Populus and Salix spp., had the greatest bark and wood Hg concentrations reaching 18 ng/g, significantly higher than for inland trees Quercus and Acer spp. with maximum values of 7 and 1.2 ng/g for bark and wood respectively. While tree cores cannot be reliably used as temporal THg biomonitors, there is promise for tree species such as Populus spp and Salix spp as spatial indicators of local long-term Hg contamination. - Total mercury trends in several deciduous trees did not follow expected environmental trends. Shoreline species (willow and popular) had higher wood THg than inland species (oak and maple).

Response of Salix alba L. to heavy metals and diesel fuel ...

African Journals Online (AJOL)

Response of Salix alba L. to heavy metals and diesel fuel contamination. ... Ni and Pb led to reduced accumulation of Pb. Presence of 5 g/kg of diesel fuel in soil significantly increased toxic influence of applied heavy metals by further reducing ... Key words: Cd, Ni, Pb, phytoremediation, phytoextraction, willow, Salix alba.

Genetic variation for characters of importance for growth in Salix viminalis L. Final report; Genetisk variation foer karaktaerer av betydelse foer tillvaext hos Salix viminalis L. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Roennberg-Waestljung, Ann Christin; Gullberg, Urban [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Plant Biology

2000-04-01

The overall goal for this project was to study the genetic variation and the genetic relationships for different growth characters and for water use efficiency (WUE) in Salix viminalis and also to use this knowledge to formulate breeding goals for Salix. Two factorial crossings with Swedish and Polish origin, each with 320 families have been used. Part of the Polish material was used to study the genetic variation for carbon isotope quota. Carbon isotope quota gives a measure of the WUE for the plant. Crossings have been made to change and improve the WUE in Salix viminalis. Construction of a genetic linkage map has started and the map can be used to identify genetic markers for WUE. The results show that most of the growth characters have both additive genetic variation and also a high degree of dominance genetic variation. A strategy in the breeding where both additive and dominance variation can be utilized should be adopted. WUE show mainly additive genetic variation but also a high heritability. This gives great opportunities to improve Salix material for WUE through recurrent selection.

Effects of contaminated soil on the growth performance of young Salix (Salix schwerinii E. L. Wolf) and the potential for phytoremediation of heavy metals.

Science.gov (United States)

Salam, Mir Md Abdus; Kaipiainen, Erik; Mohsin, Muhammad; Villa, Aki; Kuittinen, Suvi; Pulkkinen, Pertti; Pelkonen, Paavo; Mehtätalo, Lauri; Pappinen, Ari

2016-12-01

Salix schwerinii was tested in a pot experiment to assess plant growth performance i.e., relative height and dry biomass and the potential for heavy metal uptake in soils polluted with chromium, zinc, copper, nickel and total petroleum hydrocarbons. The soil used in the pot experiment was collected from a landfill area in Finland. Peat soil was added at different quantities to the polluted soil to stimulate plant growth. The plants were irrigated with tap water or processed water (municipal waste water) to further investigate the effects of nutrient loading on plant biomass growth. The soil was treated at two pH levels (4 and 6). The results showed that the addition of 40-70% peat soil at pH 6 to a polluted soil, and irrigation with processed water accelerated plant growth and phytoextraction efficiency. In the pot experiment, Salix grown in chromium, zinc, copper, nickel and total petroleum hydrocarbons -contaminated field soil for 141 days were unaffected by the contaminated soil and took up excess nutrients from the soil and water. Total mean chromium concentration in the plant organs ranged from 17.05 to 250.45 mg kg -1 , mean zinc concentration ranged from 142.32 to 1616.59 mg kg -1 , mean copper concentration ranged from 12.11 to 223.74 mg kg -1 and mean nickel concentration ranged from 10.11 to 75.90 mg kg -1 . Mean chromium concentration in the plant organs ranged from 46 to 94%, mean zinc concentration ranged from 44 to 76%, mean copper concentration ranged from 19 to 54% and mean nickel concentration ranged from 8 to 21% across all treatments. Under the different treatments, chromium was taken up by Salix in the largest quantities, followed by zinc, copper and nickel respectively. Salix also produced a moderate reduction in total petroleum total petroleum hydrocarbons in the polluted soil. The results from the pot experiment suggest that Salix schwerinii has the potential to accumulate significant amounts of chromium, zinc, copper and nickel

Feeding preferences of the willow sawfl y Nematus oligospilus (Hymenoptera: Tenthredinidae for commercial Salix clones Preferencias alimentarias de la avispa sierra de los sauces Nematus oligospilus (Hymenoptera: Tenthredinidae por clones de Salix comerciales

Directory of Open Access Journals (Sweden)

Verónica Loetti

2012-06-01

Full Text Available Nematus oligospilus Förster (Hymenoptera: Tenthredinidae is a willow sawfly native to the Northern Hemisphere which became a serious defoliator in willow plantations (Salix spp. of the Southern Hemisphere after being introduced in the early 1980´s. Studies on host preferences provide useful information for the development of pest management strategies where the willow sawfly may produce tree damage and economic loss. Feeding preferences of N. oligospilus larvae were evaluated in laboratory trials by simultaneously offering leaves from four willow tree clones commonly used in commercial plantations in Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13-44. Larvae of N. oligospilus fed on leaves from the four clones. However, insects consumed a significantly higher proportion of S. babylonica var sacramenta leaves than of leaves from the other clones. Results indicate that all clones used in the trials were palatable to the insect, and that S. babylonica var sacramenta is the preferred host for larval herbivory.Nematus oligospilus Förster (Hymenoptera: Tenthredinidae, o la avispa sierra de los sauces, es nativa del Hemisferio Norte y se ha convertido en un serio defoliador en plantaciones de sauces (Salix spp. del Hemisferio Sur, después de su introducción a principios de 1980. Los estudios sobre las preferencias de hospedador aportan información útil para el desarrollo de estrategias, donde la avispa sierra puede producir daño a los árboles y pérdidas económicas. Se evaluó la preferencia alimentaria de las larvas de N. oligospilus, mediante ensayos de laboratorio; se ofrecieron en forma simultánea hojas de cuatro clones de sauce, usados comúnmente en plantaciones comerciales en Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13

Assembly and comparative analysis of complete mitochondrial genome sequence of an economic plant Salix suchowensis

Directory of Open Access Journals (Sweden)

Ning Ye

2017-03-01

Full Text Available Willow is a widely used dioecious woody plant of Salicaceae family in China. Due to their high biomass yields, willows are promising sources for bioenergy crops. In this study, we assembled the complete mitochondrial (mt genome sequence of S. suchowensis with the length of 644,437 bp using Roche-454 GS FLX Titanium sequencing technologies. Base composition of the S. suchowensis mt genome is A (27.43%, T (27.59%, C (22.34%, and G (22.64%, which shows a prevalent GC content with that of other angiosperms. This long circular mt genome encodes 58 unique genes (32 protein-coding genes, 23 tRNA genes and 3 rRNA genes, and 9 of the 32 protein-coding genes contain 17 introns. Through the phylogenetic analysis of 35 species based on 23 protein-coding genes, it is supported that Salix as a sister to Populus. With the detailed phylogenetic information and the identification of phylogenetic position, some ribosomal protein genes and succinate dehydrogenase genes are found usually lost during evolution. As a native shrub willow species, this worthwhile research of S. suchowensis mt genome will provide more desirable information for better understanding the genomic breeding and missing pieces of sex determination evolution in the future.

Altered stream-flow regimes and invasive plant species: The Tamarix case

Science.gov (United States)

Stromberg, J.C.; Lite, S.J.; Marler, R.; Paradzick, C.; Shafroth, P.B.; Shorrock, D.; White, J.M.; White, M.S.

2007-01-01

Aim: To test the hypothesis that anthropogenic alteration of stream-flow regimes is a key driver of compositional shifts from native to introduced riparian plant species. Location: The arid south-western United States; 24 river reaches in the Gila and Lower Colorado drainage basins of Arizona. Methods: We compared the abundance of three dominant woody riparian taxa (native Populus fremontii and Salix gooddingii, and introduced Tamarix) between river reaches that varied in stream-flow permanence (perennial vs. intermittent), presence or absence of an upstream flow-regulating dam, and presence or absence of municipal effluent as a stream water source. Results: Populus and Salix were the dominant pioneer trees along the reaches with perennial flow and a natural flood regime. In contrast, Tamarix had high abundance (patch area and basal area) along reaches with intermittent stream flows (caused by natural and cultural factors), as well as those with dam-regulated flows. Main conclusions: Stream-flow regimes are strong determinants of riparian vegetation structure, and hydrological alterations can drive dominance shifts to introduced species that have an adaptive suite of traits. Deep alluvial groundwater on intermittent rivers favours the deep-rooted, stress-adapted Tamarix over the shallower-rooted and more competitive Populus and Salix. On flow-regulated rivers, shifts in flood timing favour the reproductively opportunistic Tamarix over Populus and Salix, both of which have narrow germination windows. The prevailing hydrological conditions thus favour a new dominant pioneer species in the riparian corridors of the American Southwest. These results reaffirm the importance of reinstating stream-flow regimes (inclusive of groundwater flows) for re-establishing the native pioneer trees as the dominant forest type. ?? 2007 The Authors Journal compilation ?? 2007 Blackwell Publishing Ltd.

Initial spacing of poplars and willows grown as arable coppice

Energy Technology Data Exchange (ETDEWEB)

Armstrong, A.; Johns, C.

1997-11-01

Two clones of poplar and two clones of willow were grown at two sites, on a three year cutting cycle, at six different square spacings, between 0.8 metres and 1.5 metres. The two willow clones 'Bowles hybrid' and 'Dasyclados' were planted at both sites. The poplar clones Populus interamericana 'Beaupre' and Populus trichocarpa 'Columbia River'' were planted at Wishanger in Hampshire. The poplar clones Populus interamericana 'Boelare' and Populus trichocarpa 'Trichobel' were planted at Downham Market in Norfolk. The highest yield of 17.55 oven dry tonnes per hectare (odt/ha/annum) was obtained from 'Bowles hybrid', at the closest spacing, grown on a water meadow adjacent to the River Wey at Wishanger. The highest yield for all clones at both sites was achieved at the closest spacing (in this first rotation). There was a significant linear effect. One of the most interesting observations was that when comparing the gradient of the linear relationship, within species, the gradient was steeper for the higher yielding clone. This was particularly so for the willows. This would suggest that higher yielding clones are more tolerant of crowding, or, that upright Salix viminalis make better use of close space than the more spreading Salix dasyclados. The new Salix x Salix schwerinnii hybrids should therefore also be responsive to closer spacing. The same effect was observed for the poplars at Wishanger only, but the difference was not as dramatic. There was a suggestion from the highest yielding poplar plots that optimum yield may still be obtained at the currently recommended spacing of 1.0 metre x 1.0 metre. (author)

Production costs for SRIC Populus biomass

International Nuclear Information System (INIS)

Strauss, C.H.

1991-01-01

Production costs for short rotation, intensive culture (SRIC) Populus biomass were developed from commercial-sized plantations under investigation throughout the US. Populus hybrid planted on good quality agricultural sites at a density of 850 cuttings/acre was projected to yield an average of 7 ovendry (OD) tons/acre/year. Discounted cash-flow analysis of multiple rotations showed preharvest production costs of $14/ton (OD). Harvesting and transportation expenses would increase the delivered cost to $35/ton (OD). Although this total cost compared favorably with the regional market price for aspen (Populus tremuloides), future investments in SRIC systems will require the development of biomass energy markets

VEGETATIVNO RAZMNOŽEVANJE TOPOLOV (Populus spp.) S POTAKNJENCI

OpenAIRE

Sternad, Rebeka

2010-01-01

Raziskava je bila opravljena na treh vrstah topolov: črnem topolu (Populus nigra L.), belem topolu (Populus alba L.) in trepetliki (Populus tremula L.). Namen diplomskega dela je bil proučiti ukoreninjenje potaknjencev topolov glede na okolje koreninjenja, termin potikanja in vrsto uporabljenega substrata. Zeleni in pololeseneli potaknjenci so bili večinoma nabrani v okolici celjske regije in Žalca. Koreninjeni so bili v šestih terminih (od junija do septembra) v okolju meglenja in neposredne...

Phylogenetic Relationships between Four Salix L. Species Based on DArT Markers

Directory of Open Access Journals (Sweden)

Jerzy A. Przyborowski

2013-12-01

Full Text Available The objectives of this study were to evaluate the usefulness of DArT markers in genotypic identification of willow species and describe genetic relationships between four willow species: Salix viminalis, S. purpurea, S. alba and S. triandra. The experimental plant material comprised 53 willow genotypes of these four species, which are popularly grown in Poland. DArT markers seem to identify Salix species with a high degree of accuracy. As a result, the examined species were divided into four distinct groups which corresponded to the four analyzed species. In our study, we observed that S. triandra was very different genetically from the other species, including S. alba which is generally classified into the same subgenus of Salix. The above corroborates the findings of other authors who relied on molecular methods to reveal that the classification of S. triandra to the subgenus Salix was erroneous. The Principal Coordinate Analysis (PCoA and the neighbor-joining dendrogram also confirmed the clear division of the studied willow genotypes into four clusters corresponding to individual species. This confirmed the usefulness of DArT markers in taxonomic analyses and identification of willow species.

Subcellular localization of cadmium in hyperaccumulator Populus ...

African Journals Online (AJOL)

In this study, subcellular localization of cadmium in hyperaccumulator grey poplar (Populus × canescens) was investigated by the transmission electron microscopy (TEM) method. Young Populus × canescens were grown and hydroponic experiments were conducted under four Cd2+ concentrations (10, 30, 50, and 70 μM) ...

Sex-Specific Response to Stress in Populus

Directory of Open Access Journals (Sweden)

Nataliya V. Melnikova

2017-10-01

Full Text Available Populus is an effective model for genetic studies in trees. The genus Populus includes dioecious species, and the differences exhibited in males and females have been intensively studied. This review focused on the distinctions between male and female poplar and aspen plants under stress conditions, such as drought, salinity, heavy metals, and nutrient deficiency on morphological, physiological, proteome, and gene expression levels. In most studies, males of Populus species were more adaptive to the majority of the stress conditions and showed less damage, better growth, and higher photosynthetic capacity and antioxidant activity than that of the females. However, in two recent studies, no differences in non-reproductive traits were revealed for male and female trees. This discrepancy of the results could be associated with experimental design: different species and genotypes, stress conditions, types of plant materials, sampling sizes. Knowledge of sex-specific differences is crucial for basic and applied research in Populus species.

Allelopathic potential of populus euphratica olivier

International Nuclear Information System (INIS)

Sher, Z.; Hussain, F.; Ahmad, B.; Wahab, M.

2011-01-01

Populus euphratica Olivier is frequently cultivated deciduous tree in Pakistan on agricultural land for its shade, fodder, timber and fuel wood. A relatively reduced under storey is often observed below it. Therefore the present study was conducted to assess the allelopathic potential of Populus euphratica against some crop species. Plant material of Populus euphratica were collected from the agriculture fields of Lahor, District Swabi in 2008 and were dried at room temperature (258 deg. C-308 deg. C). Allelopathic studies conducted by using aqueous extracts from various parts including young leaves, mature leaves, bark, litter and mulching in various experiments invariably retarded the germination, plumule, radical growth, fresh and dry weight of Sorghum vulgare Perse, Setaria italica (L.) P. Beauv and Triticum aestivum L., in laboratory experiments. The aqueous extracts obtained after 48 h were more inhibitory than 24 h. Leaves were more toxic than bark. Litter and mulching experiments also proved to be inhibitory. It is suggested that the various assayed parts of Populus euphratica have strong allelopathic potential at least against the tested species. Further investigation is required to see its allelopathic behavior under field condition against its associated species and to identify the toxic principles. (author)

Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae

Directory of Open Access Journals (Sweden)

Carromberth Carioca Fernandes

2009-01-01

Full Text Available Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas, of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin, were determined through analyses of NMR 1D (¹H and 13C and NMR 2D (gHSQC and gHMBC. These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae. The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active.

Salicylates isolated from leaves and stems of Salix martiana Leyb. (Salicaceae); Salicilatos isolados de folhas e talos de Salix martiana Leyb. (Salicaceae)

Energy Technology Data Exchange (ETDEWEB)

Fernandes, Carromberth Carioca [Universidade Federal do Acre (UFAC), Rio Branco, AC (Brazil). Centro de Ciencias Biologicas e da Natureza; Cursino, Lorena Mayara de Carvalho; Novaes, Jussival de Abreu Pinheiro; Demetrio, Camilla Avelino; Pereira Junior, Orlando Liborio; Nunez, Cecilia Veronica [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Produtos Naturais; Amaral, Ieda Leao do [Instituto de Pesquisa da Amazonia (INPA), Manaus, AM (Brazil). Coordenacao de Pesquisas em Botanica

2009-07-01

Salix martiana Leyb. is an endemic species from the Amazon river floodplain areas (varzeas), of the State of Amazonas. Stems and leaves were extracted with dichloromethane, methanol and hydro-alcohol and these extracts were fractionated by using conventional chromatographic techniques. The major substances isolated, salicin and trichocarposide (6-0-p-coumaroyl salicin), were determined through analyses of NMR 1D ({sup 1}H and {sup 13}C) and NMR 2D (gHSQC and gHMBC). These compounds were isolated for the first time in Salix martiana Leyb. (Salicaceae). The percentage of these compounds in S. martiana is very high. The extracts were analyzed for their DPPH antioxidant capacity and the methanolic from the leaves and the hydro-alcoholic from the stems were the more active. (author)

Feeding preferences of the willow sawfly Nematus oligospilus (Hymenoptera: Tenthredinidae for commercial Salix clones

Directory of Open Access Journals (Sweden)

Verónica LOETTI

2012-01-01

Full Text Available Nematus oligospilus Förster (Hymenoptera: Tenthredinidae, o la avispa sierra de los sauces, es nativa del Hemisferio Norte y se ha convertido en un serio defoliador en plantaciones de sauces (Salix spp. del Hemisferio Sur, después de su introducción a principios de 1980. Los estudios sobre las preferencias de hospedador aportan información útil para el desarrollo de estrategias, donde la avispa sierra puede producir daño a los árboles y pérdidas económicas. Se evaluó la preferencia alimentaria de las larvas de N. oligospilus, mediante ensayos de laboratorio; se ofrecieron en forma simultánea hojas de cuatro clones de sauce, usados comúnmente en plantaciones comerciales en Argentina (Salix babylonica var sacramenta Hortus, Salix nigra Marsch., S. babylonica L. x Salix alba L. 131-27 and Salix matsudana Koidz. x S. alba L. 13-44. Las larvas de N. oligospilus se alimentaron de las hojas de los cuatro clones. Sin embargo, consumieron una proporción significativamente mayor de las hojas de S. babylonica var sacramenta. Estos resultados indican que todos los clones utilizados en los ensayos fueron palatables para el insecto y que S. babylonica var sacramenta es el hospedador preferido para la herbivoría de las larvas.

Pelletizing using forest fuels and Salix as raw materials. A study of the pelletizing properties; Pelletering med skogsbraensle och Salix som raavara. En undersoekning av pelleterbarheten

Energy Technology Data Exchange (ETDEWEB)

Martinsson, Lars; Oesterberg, Stefan [Swedish National Testing and Research Inst., Boraas (Sweden)

2004-08-01

Three common forest fuels: light thinning material, cull tree and logging residues as well as energy forest fuel (Salix) has been used as fuel pellet materials. Logging residues and Salix were stacked for approximately 6 and 10 months respectively. Parameters varied for each raw material have been the moisture content and the press length of the die. These parameters have been changed to obtain best possible quality, mainly concerning mechanical durability. Pellets were also produced from bark free shavings in order to use as a reference in this study. Physical as well as chemical properties have been compared. It was comparatively easy to press logging residues and Salix into durable pellets and, even with larger press length, the production of pellets was higher than it was for the other raw materials. The density was equal for all pellets while the mechanical durability was better for all tested raw materials compared with the reference material. The fact that all raw materials besides the reference material contains bark which has an improving effect on the degree of hardness. The quality properties were mainly about the same or better for pellets made of light thinning material and cull tree respectively, compared with the reference pellets. However, the ash content was approximately twice as high compared with the reference pellets. The pellets made of logging residues and Salix respectively were of very good quality concerning duration and density but the ash content was approximately 10 times higher than in the reference pellets. Additionally, the nitrogen content was 6-9 times higher compared with the reference pellets.

Increasing the productivity of short-rotation Populus plantations. Final report

Energy Technology Data Exchange (ETDEWEB)

DeBell, D.S.; Harrington, C.A.; Clendenen, G.W.; Radwan, M.A.; Zasada, J.C. [Forest Service, Olympia, WA (United States). Pacific Northwest Research Station

1997-12-31

This final report represents the culmination of eight years of biological research devoted to increasing the productivity of short rotation plantations of Populus trichocarpa and Populus hybrids in the Pacific Northwest. Studies provide an understanding of tree growth, stand development and biomass yield at various spacings, and how patterns differ by Populus clone in monoclonal and polyclonal plantings. Also included is some information about factors related to wind damage in Populus plantings, use of leaf size as a predictor of growth potential, and approaches for estimating tree and stand biomass and biomass growth. Seven research papers are included which provide detailed methods, results, and interpretations on these topics.

Evaluating growth effects from an imidacloprid treatment in black willow and eastern cottonwood cuttings

Science.gov (United States)

Luciano de Sene Fernandes; Ray A. Souter; Theodor D. Leininger

2015-01-01

Black willow (Salix nigra Marsh.) and eastern cottonwood (Populus deltoides Bartram ex Marsh.), two species native in the Lower Mississippi Alluvial Valley, have importance in short rotation woody crop (SRWC) systems for biomass production (Ruark 2006).

Demonstration cultivation of Salix in northern Sweden with a focus on frost resistance; Demonstrationsodling av Salix i Norrland med frosttolerans i fokus

Energy Technology Data Exchange (ETDEWEB)

Soederstroem, Yvonne

2010-06-15

This project is part of the Thermal Engineering Research Association's (Vaermeforsk) programme 'Crops from field to energy production' and the goal is to convince growers to begin cultivating Salix in the northern part of Sweden. The project will demonstrate whether it is possible to grow Salix and examine what type of Salix (the report refers to the different types as Tora, Karin and Gudrun) is most frost-resistant and resistant to insects, fungal infections and animals. The project is aimed primarily at landowners and energy companies. The results showed that growth at the demonstration plots was moderate and the establishment rate was considered good. Growth has been uneven across the fields. At Eriksgaard, about 75% of the plants survived the winter. Survival was determined by the number of plants missing and dead. Additional plants were planted at the sites in 2009. No major insect or leaf fungus attacks were noted at either Eriksgaard or Soergaard, but they both experienced grazing from deer and elk. The rating showed that the herbicide treatment was not sufficient on the demonstration fields. For this reason, a comparison of average lengths was performed of Gudrun in Bodum, where the weeds had not grown as much. The comparison showed that the difference in growth was not significant in the autumn 2008, but the plants in Bodum had grown more by autumn 2009. Topping was not performed in the spring 2009 so that the plants would have an opportunity to grow higher than the weeds and the plants would have an opportunity to have a growth spurt. A comparison of Tora, Karin and Gudrun in Roedoen showed moderate growth for the three types. There were variations in the rows and across the field, mostly for Tora and Karin. Gudrun had lower, but more consistent growth across the field. During the summer 2009, survival was rated for the plants in Roedoen. This rating showed that 90% of Tora, 60% of Karin and 70% of Gudrun had survived the winter. The Salix

Mycorrhizal symbioses of Salix repens : diversity and functional significance

NARCIS (Netherlands)

Heijden, van der E.W.

2000-01-01

This thesis investigates the significance of different mycorrhizal fungi, belonging to different functional types (arbuscular mycorrhiza-AM and ectomycorrhiza-EcM), in Salix repens . A comparison between above-ground and below-ground observations on ectomycorrhizal

Phytopharmacology and medicinal properties of Salix aegyptiaca L.

African Journals Online (AJOL)

enoh

2012-04-05

Apr 5, 2012 ... The anti-inflammatory and antinociceptive properties of extracts of Salix family ... Iranian people for its calming effect on heart and possibly its antihypertensive .... cancer, Alzheimer's disease, Parkinson's disease and even in aging ... with patient's normal activity and are often difficult to stop once the therapy ...

The role and significance of Salix plantations for energy in Swedish agriculture

Energy Technology Data Exchange (ETDEWEB)

Forsse, L.S.; Ledin, S.; Johansson, H. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden)

1993-12-31

Fifteen years of research and development of energy forestry with Salix species has lead to a firm basis of knowledge concerning the basic biology, stand ecology and production systems of fast growing willows in Sweden. The biology research program continues to emphasize studies of plant biology and diseases as well as areas such as clone/site interactions, mixed clonal plantations and breeding. The technological research and development concentrates on functional and effective machinery for planting, harvesting, etc. Recently Salix plantations for energy production in Sweden have been commercialized. Plantations start with 18,000 cuttings of willow clones per hectare. During the first summer weed control is the most important treatment. Fertilizers are applied to keep a high production level. Crops are harvested during winter at 3--5 year intervals. The average annual production is about 10--12 tonnes DM per hectare. The life of Salix plantations is estimated as 25--30 years. An estimated potential of 300,000 hectares of Salix plantations would result 5% of the energy needs in Sweden. Wood fuel from the conventional forest equals 60 TWh today, with a potential of being doubled within 10--20 years. The economic outcome for the farmer of growing Salix mainly depends on the price of chips and the level of production. A fundamental requirement for establishing plantations is that there is a wood fuel market within a reasonable distance (about 50 km). In a calculation stretching over a period of 24 years with a production level of 12 tonnes DM per hectare and year, and at an interest rate of 6%, the net return is about 1,000--1,500 SEK/ha/yr (about 7 SEK/US$) if simultaneous chipping is used. With separate harvest and chipping and enterprise in this calculation breaks even. Interest in the utilization of sludge, ash, waste water and leakage water as nutrients for energy forests is increasing from local and regional authorities.

Laboratory-scale measurements of N2O and CH4 emissions from hybrid poplars (Populus deltoides x Populus nigra).

Science.gov (United States)

McBain, M C; Warland, J S; McBride, R A; Wagner-Riddle, C

2004-12-01

The purpose of this study was to determine whether or not young hybrid poplar (Populus deltoides x Populus nigra) could transport landfill biogas internally from the root zone to the atmosphere, thereby acting as conduits for landfill gas release. Fluxes of methane (CH4) and nitrous oxide (N2O) from the seedlings to the atmosphere were measured under controlled conditions using dynamic flux chambers and a tunable diode laser trace gas analyser (TDLTGA). Nitrous oxide was emitted from the seedlings, but only when extremely high soil N2O concentrations were applied to the root zone. In contrast, no detectable emissions of CH4 were measured in a similar experimental trial. Visible plant morphological responses, characteristic of flood-tolerant trees attempting to cope with the negative effects of soil hypoxia, were observed during the CH4 experiments. Leaf chlorosis, leaf abscission and adventitious roots were all visible plant responses. In addition, seedling survival was observed to be highest in the biogas 'hot spot' areas of a local municipal solid waste landfill involved in this study. Based on the available literature, these observations suggest that CH4 can be transported internally by Populus deltoides x Populus nigra seedlings in trace amounts, although future research is required to fully test this hypothesis.

Woody riparian vegetation response to different alluvial water table regimes

Science.gov (United States)

Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

2000-01-01

Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

Establishment and early management of Populus species in southern Sweden

OpenAIRE

Mc Carthy, Rebecka

2016-01-01

Populus species are among the most productive tree species in Sweden. Interest in growing them has increased during the 21st century due to political goals to increase the share of renewable energy and to increase the proportion of hardwood species in forests. Populus species have been shown to be potentially profitable, but currently they are mostly planted on abandoned agricultural land. There is a lack of knowledge about the establishment of Populus species on forest sites. There is also a...

Wastewater sludge fertilization: Biomass productivity and heavy metal bioaccumulation in two Salix species grown in southern Quebec (Canada)

International Nuclear Information System (INIS)

Teodorescu, T.I.; Labrecque, M.; Daigle, S.; Poisson, G.

1993-01-01

More than other kind of trees, fast growing tree species, such as willows, can profit from sludge application. While sludges are good fertilizers, they may also contain heavy metals which could reduce productivity and cause risks to the environment. The main aims of the present research were to study: (1) the production capacity of Salix discolor and Salix viminalis when supplied with various amounts of dried and pelleted sludge; (2) the uptake, and accumulation of heavy metals. Unrooted cuttings were planted on sandy soil in large plastic pots and grown in outdoors for 20-week period. Five doses of sludge were applied: equivalent of 200 (T1), 160 (T2), 120 (T3), 80 (T4) and 40 (T5) kg N per ha. Trees which received the largest amount of sludge showed the best growth results. The stem-branch biomass was significantly higher for Salix viminalis. The relationship between the total yield biomass Y (t/ha) and the rate of fertilization X (kg N/ha) is linear. The regression equations of prediction biomass production were established as following: Salix discolor Y = 1.807 + 0.037X and Salix viminalis Y = 2.578 + 0.042X. For both species, greatest stems-branch biomass per gram of N applied were produced by treatments 1 and 2. The amount of nitrogen per leaf area (N/LA) and per leaf dry weight (N/LW), were higher for Salix viminalis which leads us believe that its photosynthetic activity was better. The transfer coefficient did not vary between the species but was significantly different for Cd and Zn. The plants were able to absorb Cd and Zn but less of Ni, Hg and Cu and Pb. It was concluded that the dried and pelleted sludge can be a good fertilizer. The treatment is beneficial when Salix discolor and particulary Salix viminalis are used as vegetation filters for wastewater sludge purification and production purposes

Barcoding poplars (Populus L. from western China.

Directory of Open Access Journals (Sweden)

Jianju Feng

Full Text Available BACKGROUND: Populus is an ecologically and economically important genus of trees, but distinguishing between wild species is relatively difficult due to extensive interspecific hybridization and introgression, and the high level of intraspecific morphological variation. The DNA barcoding approach is a potential solution to this problem. METHODOLOGY/PRINCIPAL FINDINGS: Here, we tested the discrimination power of five chloroplast barcodes and one nuclear barcode (ITS among 95 trees that represent 21 Populus species from western China. Among all single barcode candidates, the discrimination power is highest for the nuclear ITS, progressively lower for chloroplast barcodes matK (M, trnG-psbK (G and psbK-psbI (P, and trnH-psbA (H and rbcL (R; the discrimination efficiency of the nuclear ITS (I is also higher than any two-, three-, or even the five-locus combination of chloroplast barcodes. Among the five combinations of a single chloroplast barcode plus the nuclear ITS, H+I and P+I differentiated the highest and lowest portion of species, respectively. The highest discrimination rate for the barcodes or barcode combinations examined here is 55.0% (H+I, and usually discrimination failures occurred among species from sympatric or parapatric areas. CONCLUSIONS/SIGNIFICANCE: In this case study, we showed that when discriminating Populus species from western China, the nuclear ITS region represents a more promising barcode than any maternally inherited chloroplast region or combination of chloroplast regions. Meanwhile, combining the ITS region with chloroplast regions may improve the barcoding success rate and assist in detecting recent interspecific hybridizations. Failure to discriminate among several groups of Populus species from sympatric or parapatric areas may have been the result of incomplete lineage sorting, frequent interspecific hybridizations and introgressions. We agree with a previous proposal for constructing a tiered barcoding system in

Wound-induced proteinase inhibitor in Salix viminalis and its association with defence against insects

Energy Technology Data Exchange (ETDEWEB)

Saarikoski, P. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Genetics

1997-09-01

For successful traditional breeding, the plant material has to be screened for genetic variation for the desired traits. By screening Salix clones for wound-induced proteinase inhibitor (PI) activity and ethylene evolution, it was possible to identify variation for both characters among the Salix clones tested. However, no correlation was observed with insect and pathogen resistance. Since there was no simple relationship between wound-induced ethylene production, accumulation of PI and pest resistance, a more systematic investigation of Salix PIs was begun. A gene (swin1.1) encoding a 21 kDa trypsin inhibitor with characteristics of Kunitz-type of PI was sequenced. The trypsin inhibitor encoded by the isolated swin1.1 gene was shown to be functional in vitro and exhibit specificity for trypsin. It is therefore likely that this PI is involved in the plant defence in Salix, since many insects have trypsin as their major digestive protease. In further support of this view, in bio-tests with poplar the mortality of the first instar larvae (Lymantria dispar) was significantly increased, both after application of the trypsin inhibitor encoded by swin1.1 directly on poplar leaves and after feeding the larvae with transgenic poplar over-expressing the swin1.1 gene. In Salix, the swin1.1 gene was shown to be induced by mechanical wounding, insect feeding and by treatment with the signalling substances salicylic and jasmonic acid. The locally wound-induced response (mechanical and insect) was greater than the systemic response. Other swin1 gene family members were also differentially expressed after the inductive treatment. 187 refs., 3 figs., 2 tabs.

Resprout and survival of willows (Salix purpurea and S. incana), Poplars (Populus nigra) and Tamaris (Tamarix gallica) cuttings in marly gullies with Southern aspect in a mountainous and Mediterranean climate (Southern Alps, France)

Science.gov (United States)

Rey, Freddy; Labonne, Sophie; Dangla, Laure; Lavandier, Géraud

2014-05-01

In the Southern French Alps under a mountainous and Mediterranean climate, a current strategy of bioengineering is developed for trapping sediment in marly gullies with surface area less than 1 ha. It is based on the use of structures in the form of brush layers and brush mats of cuttings on deadwood microdams. Purple and white Willows (Salix purpurea and S. incana) are recommended here as they proved their efficiency to resprout and survive in such environment. However, these species installed in Southern gullies did not survive in previous experiments, due to the too harsh conditions of solar radiation and drought. We thus decided to test other species, namely black Poplar (Populus nigra) and Tamaris (Tamarix gallica), which proved their resistance to drought conditions in other experiments. To this view, bioengineering structures have been built in 2010 in eroded marly gullies in the Roubines and Fontaugier catchments (Southern Alps, France). We tested two installation modalities: one in spring and a second in autumn. Seventy-eight bioengineering structures (50 in spring and 28 in autumn), among which 32 made with Poplar cuttings and 28 with Tamaris cuttings, as well as 11 structures with purple Willow and 7 with white Willow as controls, were built in 6 experimental gullies. After 3 observation years for each modality (2010 to 2012, and 2011 to 2013, respectively), results first revealed that Willow species succeeded in surviving in gullies in Southern aspect (76 % for the cuttings installed in spring and 52 % for those installed in autumn), which is in contradiction with previous results. Second, Poplar showed a good ability to survive (62 % for the cuttings installed in spring and 33 % for those installed in autumn). Tamaris obtained the worst score with 26 % and 38 % of survival for the cuttings installed in spring and autumn, respectively. Globally, excepted for Tamaris, survival rates were better for the cuttings installed in spring. The bioengineering

Growth and biomass of Populus irrigated with landfill leachate

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny; David R. Coyle; Richard B. Hall

2007-01-01

Resource managers are challenged with waste disposal and leachate produced from its degradation. Poplar (Populus spp.) trees offer an opportunity for ecological leachate disposal as an irrigation source for managed tree systems. Our objective was to irrigate Populus trees with municipal solid waste landfill leachate or fertilized well water (control...

Effects of long-term Salix cultivation on total and plant-available contents of Cadmium in the soil - a pilot study

International Nuclear Information System (INIS)

Eriksson, Jan; Ledin, S.

1996-02-01

The aim of the project was to study how total and plant-available contents of Cadmium in the soil are affected by the large amounts of Cadmium that are removed during the harvesting of Salix. Eight long-term Salix plantations, 8-30 years old, were chosen. At each place soil samples were taken in 4 areas in the stands of Salix and in 4 neighbouring areas with comparable soil conditions, but without Salix (reference areas). Cd in three fractions of different bonding strength were determined in the soil samples. The fractions roughly correspond to the total concentration, the exchangeable fraction, and the fraction dissolved in the soil solution. The result showed a relatively minor effect of the Salix plantation on the total concentrations. In six of eight cases, however, the concentrations tended to be lower in the Salix plantations than in the reference areas. When consideration was given to certain pH differences, the exchangeable, and particularly the most soluble fraction, showed a clear tendency for concentrations to be lower in the Salix stands than in the reference areas.The concentrations in stem samples from growing stands were generally lower than those measured in harvest-mature stems in other studies. The concentrations in foliage were of the same magnitude as those in the stems, implying that there is an important return of Cd to the soil at leaf-fall. The negligible effect on the total content in the soil may depend on uptake occurring both in the topsoil and in the subsoil. Re-circulation via the leaves will also result in redistribution of Cd from the subsoil to the topsoil, compensating the uptake from the topsoil. The conclusion reached was that Salix cultivation results in a reduction of the plant-available Cd in the soil, but the effect is not concentrated to the topsoil. 13 refs, 5 tabs, 4 figs

Uptake of cadmium from hydroponic solutions by willows ( Salix spp ...

African Journals Online (AJOL)

Salix integra 'Weishanhu') and Yizhibi (S. integra 'Yizhibi') were chosen as model plants to evaluate their potential for uptake of cadmium from hydroponic culture and relative uptake mechanism. Cadmium uptake showed a linear increase in the ...

Nanoscale Phenomena Occurring during Pyrolysis of Salix viminalis Wood

Directory of Open Access Journals (Sweden)

Aleksandra W. Cyganiuk

2013-01-01

Full Text Available Selective utilisation of unique properties of Salix viminalis wood enables preparation of materials of nanotechnologic properties. Thermal decomposition of lignin-cellulose organic matter results in the formation of a nanostructured porous carbon matrix (charcoal. Narrowed pore size distribution (PSD in the subnanometer range allows to consider the charcoals as carbon molecular sieves (CMSs, which are capable of separating even chemically inert gases like neon, krypton, and nitrogen. High tolerance of Salix viminalis to heavy metal ions enables enriching living plant tissues with metal ions like lanthanum and manganese. Such ions may later form LaMnO3 with parallel transformation of plant tissues (organic matter to carbon matrix using a heat treatment. In this way, one gets a hybrid material: a porous carbon matrix with uniformly suspended nanocrystallites of LaMoO3. The crystallites are in the catalytically active phase during the conversion of n-butanol to heptanone-4 with high yield and selectivity.

Repeated unidirectional introgression towards Populus balsamifera in contact zones of exotic and native poplars

NARCIS (Netherlands)

Thompson, S.L.; Lamothe, M.; Meirmans, P.G.; Périnet, P.; Isabel, N.

2010-01-01

As the evolutionary significance of hybridization is largely dictated by its extent beyond the first generation, we broadly surveyed patterns of introgression across a sympatric zone of two native poplars (Populus balsamifera, Populus deltoides) in Quebec, Canada within which European exotic Populus

Estaquillas leñosas de fácil enraizamiento: Estudio del Esclerenquima Estaquillas leñosas de fácil enraizamiento: Estudio del Esclerénquima

Directory of Open Access Journals (Sweden)

González Elena

1986-12-01

Full Text Available An anatomy study was made of following wood easy-to-root species: Aucuba japonica Thunb., Buddleja  japonica Hemsley,  Buxus sempervirens L., Citrus aurantium.  L., Citrus limon (L. Burm. fil.,  Cvdonia oblonga Miller,  Erica arborea L., Escallonia rubra (Ruiz & Pavón Pers., Euonymus japonicus L. fil., Forsythia viridissima Lindl., Hydrangea macrophylla Ser., Morus alba L., Populus nigra L.,  Rhododendron ponticum L., Salix atrocinerea Brot., Salix  viminalis L., Sambucus nigra L. and Symphoricarpos albus (L. S. F. Blake.  It was observed the presence or absence of a discontinous sclerenchyma ring so the species studied had not a mechanical barrier to the emergence of adventitious roots. Se realizó un estudio histológico de las siguientes especies leñosas de fácil enraizamiento: Aucuba japonica Thumb, Buddleja japonica Hemsley, Buxus sempervirens L., Citrus aurantium L., Citrus limon (L. Burm, fil., Cydonia oblonga Miller, Erica arborea L., Escallonia rubra (Ruiz & Pavón Pers., Euonymus japonicus L. fil., Forsythia viridissima Lindl., Hydrangea macrophylla Ser., Morus alba L. Populus nigra L., Rhododendron ponticum L., Salix atrocinerea Brot., Salix viminalis L., Sambucus nigra L. y Syrnphoricarpos albus (L. S. F. Blake. Se observó la presencia o ausencia de un anillo discontinuo de esclerénquima, por lo tanto dichas especies no poseen ningún impedimento mecánico para la emergencia de las raíces adventicias.

Clonal variation in survival and growth of hybrid poplar and willow in an in situ trial on soils heavily contaminated with petroleum hydrocarbons

Science.gov (United States)

Ronald S., Jr. Zalesny; Edmund O. Bauer; Richard B. Hall; Jill A. Zalesny; Joshua Kunzman; Chris J. Rog; Don E. Riemenschneider

2005-01-01

Species and hybrids between species belonging to the genera Populus (poplar) and Salix (willow) have been used successfully for phytoremediation of contaminated soils. Our objectives were to: 1) evaluate the potential for establishing genotypes of poplar and willow on soils heavily contaminated with petroleum hydrocarbons and 2)...

Evaluation of the Efficacy of Crude Extracts of Salix subserrata and ...

African Journals Online (AJOL)

aqueous of Salix subserrata were found to increase the survival time of mice signifi- cantly (P< ... identification and authentication was done using the manual of the Depart- ... Data were analyzed using SPSS version 11.5 for windows software.

Technique for compressed bundles for harvest of whole straw willow. Pilot study; Teknik foer komprimerande helskottsskoerd av salix i buntform. Foerstudie

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Hans (Vaesteraeng Lantbruk AB (Sweden))

2008-06-15

The pilot study was initiated by the need of a new technology that has been raised from the problem, and by the specifications of requirements, that has been described from the project 'Salix Maelardalen'. The need has been crystallized by the energy company Maelarenergi AB, Vaesteraas, in their handling of bio fuel, among many other fuels. The company Maelarenergi AB can see a potential in the use of Salix of a considerable volume. There is a special need by the means of the big volume handling of Salix, since the Salix raw material must be able to be delivered under a longer period or for intermediate storage. 8-9 months could be an adequate storage period. The possibility for intermediate storage could do the flow of fuel raw material to the combined power and heating plant is harmonized to the special requirements of fuel. The storage capability in chipped raw Salix chips is very short and that's why chipped Salix are not going to be a sustainable system combined with the handle of big volume together with portioned inflow to the plant. The production of Salix chips in a system of direct chipping is a very delicate system. The ground conditions with frozen and dry grounds are important for a system with heavy machines. The last years have not given such climate conditions. A big problem with practicability has been coming up. The number of days for contract work during the harvest period without interruption, because of hard conditions, has been decreased to the level that the capacity very considerably falls below what is economical defensible. The needs of larger areas for harvesting during fewer days under good conditions counteract each other. In the 'hot flow' during the harvest when the harvest machine will work with escort vehicles/container transports in the field can be impossible to realize because of for example the breakdown of the soil structure. The organization around 'hot flow system' is a very heavy programme

7 CFR 301.51-2 - Regulated articles.

Science.gov (United States)

2010-01-01

... 7 Agriculture 5 2010-01-01 2010-01-01 false Regulated articles. 301.51-2 Section 301.51-2... Regulated articles. The following are regulated articles: (a) Firewood (all hardwood species), and green... (sycamore), Populus (poplar), Salix (willow), Sorbus (mountain ash), and Ulmus (elm). (b) Any other article...

Detection of a variable number of ribosomal DNA loci by fluorescent in situ hybridization in Populus species.

Science.gov (United States)

Prado, E A; Faivre-Rampant, P; Schneider, C; Darmency, M A

1996-10-01

Fluorescent in situ hybridization (FISH) was applied to related Populus species (2n = 19) in order to detect rDNA loci. An interspecific variability in the number of hybridization sites was revealed using as probe an homologous 25S clone from Populus deltoides. The application of image analysis methods to measure fluorescence intensity of the hybridization signals has enabled us to characterize major and minor loci in the 18S-5.8S-25S rDNA. We identified one pair of such rDNA clusters in Populus alba; two pairs, one major and one minor, in both Populus nigra and P. deltoides; and three pairs in Populus balsamifera, (two major and one minor) and Populus euroamericana (one major and two minor). FISH results are in agreement with those based on RFLP analysis. The pBG13 probe containing 5S sequence from flax detected two separate clusters corresponding to the two size classes of units that coexist within 5S rDNA of most Populus species. Key words : Populus spp., fluorescent in situ hybridization, FISH, rDNA variability, image analysis.

Seasonal Dynamics of Water Use Strategy of Two Salix Shrubs in Alpine Sandy Land, Tibetan Plateau.

Science.gov (United States)

Zhu, Yajuan; Wang, Guojie; Li, Renqiang

2016-01-01

Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant species in the alpine sandy land ecosystem is important for vegetative rehabilitation and ecological restoration. The stable isotope methodology of δD, δ18O, and δ13C was used to determine main water source and long-term water use efficiency of Salix psammophila and S. cheilophila, two dominant shrubs on interdune of alpine sandy land in northeastern Tibetan Plateau. The root systems of two Salix shrubs were investigated to determine their distribution pattern. The results showed that S. psammophila and S. cheilophila absorbed soil water at different soil depths or ground water in different seasons, depending on water availability and water use strategy. Salix psammophila used ground water during the growing season and relied on shallow soil water recharged by rain in summer. Salix cheilophila used ground water in spring and summer, but relied on shallow soil water recharged by rain in spring and deep soil water recharged by ground water in fall. The two shrubs had dimorphic root systems, which is coincident with their water use strategy. Higher biomass of fine roots in S. psammophila and longer fine roots in S. cheilophila facilitated to absorb water in deeper soil layers. The long-term water use efficiency of two Salix shrubs increased during the dry season in spring. The long-term water use efficiency was higher in S. psammophila than in S. cheilophila, as the former species is better adapted to semiarid climate of alpine sandy land.

Leaf, woody, and root biomass of Populus irrigated with landfill leachate

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny; D.R. Coyle; R.B. Hall

2007-01-01

Poplar (Populus spp.) trees can be utilized for ecological leachate disposal when applied as an irrigation source for managed tree systems. Our objective was to evaluate differences in tree height, diameter, volume, and biomass of leaf, stem, branch, and root tissues of Populus trees after two seasons of irrigation with municipal...

The potential of two Salix genotypes for radionuclide/heavy metal accumulation. A case study of Rovinari ash pit (Gorj District, Romania)

Science.gov (United States)

Hernea, Cornelia; Neţoiu, Constantin; Corneanu, Gabriel; Crăciun, Constantin; Corneanu, Mihaela; Cojocaru, Luminiţa; Rovena Lăcătuşu, Anca; Popescu, Ion

2014-05-01

Thermo Electric Power Plants (TEPP) produce a high amount of ash, that contains heavy metals and radionuclides. Ash is usually stored in ash-pits, in mixture with water and contains U235, Th 234 and their decay products, that are released from the coal matrix, during combustion, as well as heavy metals. Warm weather dried the ash and it can be spread by the wind in surrounded area. This paper presents the results of an experiment with two Salix genotypes, cultivated on an old closed ash-pit, nearby the Rovinari TEPP, in the middle Jiu valley (Gorj District, Romania), in order to evaluate its tolerance to heavy metals and radionuclides. Ash analysis revealed the presence of natural radionuclides, beloging from ash and coal dust, as well as of Cs 137, of Chernobil provenance. Radionuclides content over the normal limits for Romania were registered for Th 234, Pb210, U235 and Ra226. The heavy metals level in ash was over the normal limits, but under the alerts limits. In order to establish the woody plants tolerance to heavy metals and radionuclides, it is important to study the seedlings behavior. In this respect Salix alba and Salix viminalis whips and cuttings culture have been establish on Rovinari ash-pit. The observations made on survival and growth rate pointed out the superiority of Salix viminalis behaviour. After a period of three years Salix viminalis registered a 96% survival rate, while in Salix alba annual decreases, reaching to 14%. These results are supported by the radionuclides content in leaves and by the electron microscopy studies. In Salix alba the leaves parenchimatic cells present a low sinthesis activity. The exogenous particles are accumulated in parenchima cells vacuola, the chloroplasts are usually agranal, with few starch grains and mitocondria presents slightly dillated crista. The ultrastructural features of the mature leaf cells, evidenced the natural adaptation of Salix viminalins for development in an environment with a big amount of

Water uptake in woody riparian phreatophytes of the southwestern United States: a stable isotope study

International Nuclear Information System (INIS)

Busch, D.E.; Ingraham, N.L.; Smith, S.D.

1992-01-01

Alluvial forest associations are often dominated by woody phreatophytes, plants that are tightly linked to aquifers for water uptake. Anthropogenic hydrological alterations (e.g., water impoundment or diversion) are of clear importance to riparian ecosystem function. Because decreased frequency of flooding and depression of water tables may, in effect, sever riparian plants from their natural water sources, research was undertaken to determine water uptake patterns for the dominant native and introduced woody taxa of riparian plant communities of the southwestern United States. At floodplain study sites along the Bill Williams and lower Colorado Rivers (Arizona, USA), naturally occurring D and 18 O were used to distinguish among potential water sources. Isotopic ratios from potential uptake locations were compared to water extracted from the dominant woody taxa of the study area (Populus fremontii, Salix gooddingii, and Tamarix ramosissima) to elucidate patterns of water absorption. Isotopic composition of water obtained from sapwood cores did not differ significantly from heartwood or branch water, suggesting that heartwood water exchange, stem capacitance, and phloem sap mixing may be inconsequential in actively transpiring Salix and Populus. There was evidence for close hydrologic linkage of river, ground, and soil water during the early part of the growing season. Surface soils exhibited D enrichment due to cumulative exposure to evaporation as the growing season progressed. Isotopic ratios of water extracted from Populus and Salix did not exhibit isotopic enrichment and were not significantly different from groundwater or saturated soil water sources, indicating a phreatophytic uptake pattern. Associations of isotopic ratios with water relations parameters indicated high levels of canopy evaporation and possible use of moisture from unsaturated alluvial soils in addition to groundwater in Tamarix. (author)

Characterization of MORE AXILLARY GROWTH genes in Populus.

Directory of Open Access Journals (Sweden)

Olaf Czarnecki

Full Text Available Strigolactones are a new class of plant hormones that play a key role in regulating shoot branching. Studies of branching mutants in Arabidopsis, pea, rice and petunia have identified several key genes involved in strigolactone biosynthesis or signaling pathway. In the model plant Arabidopsis, MORE AXILLARY GROWTH1 (MAX1, MAX2, MAX3 and MAX4 are four founding members of strigolactone pathway genes. However, little is known about the strigolactone pathway genes in the woody perennial plants.Here we report the identification of MAX homologues in the woody model plant Populus trichocarpa. We identified the sequence homologues for each MAX protein in P. trichocarpa. Gene expression analysis revealed that Populus MAX paralogous genes are differentially expressed across various tissues and organs. Furthermore, we showed that Populus MAX genes could complement or partially complement the shoot branching phenotypes of the corresponding Arabidopsis max mutants.This study provides genetic evidence that strigolactone pathway genes are likely conserved in the woody perennial plants and lays a foundation for further characterization of strigolactone pathway and its functions in the woody perennial plants.

To be or not to be a subspecies: description of Saperda populnea lapponica ssp. n. (Coleoptera, Cerambycidae) developing in downy willow (Salix lapponum L.)

Science.gov (United States)

Wallin, Henrik; Kvamme, Torstein; Bergsten, Johannes

2017-01-01

Abstract A new subspecies of the European cerambycid Saperda populnea (Linnaeus, 1758) is described: Saperda populnea lapponica ssp. n. based on specimens from Scandinavia. The male genitalia characters were examined and found to provide support for this separation, as well as differences in morphology, geographical distribution and bionomy. The preferred host tree for the nominate subspecies S. populnea populnea is Populus tremula L., whereas S. populnea lapponica ssp. n. is considered to be monophagous on Salix lapponum L. DNA sequence data of mitochondrial cytochrome oxidase subunit I (COI) was generated from Scandinavian specimens of S. populnea populnea and specimens representing S. populnea lapponica ssp. n. The two subspecies were not reciprocally monophyletic and genetic distances in COI were small. All synonyms of S. populnea populnea have been considered, and species similar to S. populnea populnea have been examined, and not found to be related to S. populnea lapponica ssp. n. A male lectotype has been designated for each of the two following synonyms: Cerambyx decempunctatus De Geer, 1775, and Saperda salicis Zetterstedt, 1818. The synonymised species from Asia, S. balsamifera (Motshulsky, 1860), is elevated to subspecies: S. populnea balsamifera stat. n. We end with a discussion on the definition of subspecies under the unified species concept. PMID:29187784

Impact of abiotic factors on frost resistance and cold acclimation in Salix species and clones

Energy Technology Data Exchange (ETDEWEB)

Fircks, H. von [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Short Rotation Forestry

1996-12-31

The effects of mineral nitrogen, photoperiod and day-night temperature on frost resistance and growth cessation in Salix species and clones are discussed. Increased nitrogen supply and imbalances between nitrogen and other elements might cause extensive frost damage in plants of Salix. Vegetation frosts below -3 deg C reduces the level of annual yield. Although Salix clones differ in resistance to freezing stress, the capacity to recover and grow after frosts are equal essential properties which affect the growth and biomass production of shoots after night frosts in June. Early autumn frosts causing freezing damage not only may delay the onset of growth cessation and cold acclimation, but also affect the winter survival of shoots. Increased nitrogen supply prior to cold acclimation postponed growth cessation and cold acclimation. Differences in nutrient status in plants cause also differences in retranslocation of mineral nutrients. Absence of damaging autumn frosts allow plants irrespective of nitrogen status to develop a frost resistance of at least - 80 deg C. 21 refs, 1 fig, 3 tabs

Dense genetic linkage maps of three Populus species (Populus deltoides, P. nigra and P. trichocarpa) based on AFLP and microsatellite markers.

Science.gov (United States)

Cervera, M T; Storme, V; Ivens, B; Gusmão, J; Liu, B H; Hostyn, V; Van Slycken, J; Van Montagu, M; Boerjan, W

2001-06-01

Populus deltoides, P. nigra, and P. trichocarpa are the most important species for poplar breeding programs worldwide. In addition, Populus has become a model for fundamental research on trees. Linkage maps were constructed for these three species by analyzing progeny of two controlled crosses sharing the same female parent, Populus deltoides cv. S9-2 x P. nigra cv. Ghoy and P. deltoides cv. S9-2 x P. trichocarpa cv. V24. The two-way pseudotestcross mapping strategy was used to construct the maps. Amplified fragment length polymorphism (AFLP) markers that segregated 1:1 were used to form the four parental maps. Microsatellites and sequence-tagged sites were used to align homoeologous groups between the maps and to merge linkage groups within the individual maps. Linkage analysis and alignment of the homoeologous groups resulted in 566 markers distributed over 19 groups for P. deltoides covering 86% of the genome, 339 markers distributed over 19 groups for P. trichocarpa covering 73%, and 369 markers distributed over 28 groups for P. nigra covering 61%. Several tests for randomness showed that the AFLP markers were randomly distributed over the genome.

De novo transcriptome and small RNA analysis of two Chinese willow cultivars reveals stress response genes in Salix matsudana.

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Guodong Rao

Full Text Available Salix matsudana Koidz. is a deciduous, rapidly growing, and drought resistant tree and is one of the most widely distributed and commonly cultivated willow species in China. Currently little transcriptomic and small RNAomic data are available to reveal the genes involve in the stress resistant in S. matsudana. Here, we report the RNA-seq analysis results of both transcriptome and small RNAome data using Illumina deep sequencing of shoot tips from two willow variants(Salix. matsudana and Salix matsudana Koidz. cultivar 'Tortuosa'. De novo gene assembly was used to generate the consensus transcriptome and small RNAome, which contained 106,403 unique transcripts with an average length of 944 bp and a total length of 100.45 MB, and 166 known miRNAs representing 35 miRNA families. Comparison of transcriptomes and small RNAomes combined with quantitative real-time PCR from the two Salix libraries revealed a total of 292 different expressed genes(DEGs and 36 different expressed miRNAs (DEMs. Among the DEGs and DEMs, 196 genes and 24 miRNAs were up regulated, 96 genes and 12 miRNA were down regulated in S. matsudana. Functional analysis of DEGs and miRNA targets showed that many genes were involved in stress resistance in S. matsudana. Our global gene expression profiling presents a comprehensive view of the transcriptome and small RNAome which provide valuable information and sequence resources for uncovering the stress response genes in S. matsudana. Moreover the transcriptome and small RNAome data provide a basis for future study of genetic resistance in Salix.

The Study of Interactions between Active Compounds of Coffee and Willow (Salix sp. Bark Water Extract

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Agata Durak

2014-01-01

Full Text Available Coffee and willow are known as valuable sources of biologically active phytochemicals such as chlorogenic acid, caffeine, and salicin. The aim of the study was to determine the interactions between the active compounds contained in water extracts from coffee and bark of willow (Salix purpurea and Salix myrsinifolia. Raw materials and their mixtures were characterized by multidirectional antioxidant activities; however, bioactive constituents interacted with each other. Synergism was observed for ability of inhibition of lipid peroxidation and reducing power, whereas compounds able to scavenge ABTS radical cation acted antagonistically. Additionally, phytochemicals from willow bark possessed hydrophilic character and thermostability which justifies their potential use as an ingredient in coffee beverages. Proposed mixtures may be used in the prophylaxis or treatment of some civilization diseases linked with oxidative stress. Most importantly, strong synergism observed for phytochemicals able to prevent lipids against oxidation may suggest protective effect for cell membrane phospholipids. Obtained results indicate that extracts from bark tested Salix genotypes as an ingredient in coffee beverages can provide health promoting benefits to the consumers; however, this issue requires further study.

Tree recruitment and survival in rivers: influence of hydrological processes

Science.gov (United States)

Carter Johnson, W.

2000-10-01

The findings of a 14-year study of tree reproduction and survival in the Platte River, Nebraska, are presented. The study was initiated in 1985 to determine the causes and remedies of woodland expansion and channel narrowing, which have reduced potential roosting habitat for migratory avifauna such as the whooping crane and sandhill crane.A total of 296 relocatable sites, constituting some 600 plots with Populus and Salix seedlings, was selected and sampled within two reaches near Shelton and Odessa, Nebraska. The fate of some 37 000 tree seedlings was monitored within the plot network.Tree recruitment is controlled largely by stream flow in June. Populus and Salix produce large numbers of seedlings in the river bed in most years, indicating the potential for high rates of woodland expansion. On average, in only 1 year in 7 is stream flow in June high enough to preclude Populus and Salix recruitment.Seedling mortality is dominated by two environmental factors: summer stream flow pulses from thunderstorms, which erode or bury new germinants, and river bed restructuring by moving ice in winter. A third factor, seedling mortality by desiccation during summer droughts, does occur but at a low frequency.Plots of seedlings had extremely low survival rates over the course of the study. Forty-two per cent of the plots lost all seedlings by the first remeasurement (July to September), 36% by the second measurement (May), and 10% by the third remeasurement (July). Thus nearly 90% of the plots had lost all tree seedlings by the end of the first year.counterbalanced by erosion of established woodland.effectiveness of prescribed flows as insurance against future narrowing. Flows prescribed at key times to raise seedling mortality rates are recommended to maintain or widen channels, rather than mechanical clearing of established woodland.

Mitochondrial DNA variation and genetic relationships of Populus species.

Science.gov (United States)

Barrett, J W; Rajora, O P; Yeh, F C; Dancik, B P; Strobeck, C

1993-02-01

We examined variation in and around the region coding for the cytochrome c oxidase I (coxI) and ATPase 6 (atp6) genes in the mitochondrial genomes of four Populus species (P. nigra, P. deltoides, P. maximowiczii, and P. tremuloides) and the natural hybrid P. x canadensis (P. deltoides x P. nigra). Total cellular DNAs of these poplars were digested with 16 restriction endonucleases and probed with maize mtDNA-specific probes (CoxI and Atp6). The only variant observed for Atp6 was interspecific, with P. maximowiczii separated from the other species as revealed by EcoRI digestions. No intraspecific mtDNA variation was observed among individuals of P. nigra, P. maximowiczii, P. x canadensis, or P. tremuloides for the CoxI probe. However, two varieties of P. deltoides were distinct because of a single site change in the KpnI digestions, demonstrating that P. deltoides var. deltoides (eastern cottonwood) and var. occidentalis (plains cottonwood) have distinct mitochondrial genomes in the region of the coxI gene. Populus x canadensis shared the same restriction fragment patterns as its suspected maternal parent P. deltoides. Nucleotide substitutions per base in and around the coxI and atp6 genes among the Populus species and the hybrid ranged from 0.0017 to 0.0077. The interspecific estimates of nucleotide substitution per base suggested that P. tremuloides was furthest removed from P. deltoides and P. x canadensis and least diverged from P. nigra. Populus maximowiczii was placed between these two clusters.

Survival and death of seeds during liquid nitrogen storage: a case study on seeds with short lifespans.

Science.gov (United States)

Ballesteros, D; Pence, V C

The low temperature of liquid nitrogen is assumed to stop ageing and preserve viability indefinitely, however there are few validating data sets. The use of seeds to test these assumptions is important because other cryopreserved systems lack quantitative measures of viability to allow comparisons among timed points. To evaluate survival of a collection of seeds with short lifespans stored 12-20 years in liquid nitrogen. Seeds from 11 species (26 accessions) were removed from cryostorage and evaluated for germination and normal growth. Germination of Plantago cordata and Betula spp. seeds did not decrease significantly during cryostorage. However, Populus deltoides and most Salix spp. accessions showed a significant decrease in germination, with further loss observed when P. deltoides seedlings were followed to the young plant stage. Seeds of initial low quality showed greater deterioration during cryostorage. Cryostorage maintained viability of Salix and Populus seeds longer than other temperatures. However, ageing was not completely stopped and seed longevity was shorter than that predicted for many other species. A high initial seed quality is important in order to obtain the maximum benefit of cryostorage.

Manipulating beaver (Castor canadensis) feeding responses to invasive tamarisk (Tamarix spp.).

Science.gov (United States)

Kimball, Bruce A; Perry, Kelly R

2008-08-01

To evaluate methods for promoting consumption of tamarisk plants by beavers (Castor canadensis), we determined the feeding responses by captive beavers to diets that contained tannins and sodium chloride (hereafter referred to as tamarisk diet). In two-choice tests, beavers consumed equivalent quantities of tamarisk diet and control diet. Treatment with polyethylene glycol and fructose did not increase beaver preferences for the tamarisk diet. When offered the choice of control diet and casein hydrolysate-treated control diet, beavers strongly avoided the latter, showing feeding deterring activity of casein hydrolysate. However, when tamarisk diet was the alternative to the deterrent treatment, beavers consumed similar quantities of the two diets. Finally, beaver foraging preferences for actual plant cuttings were assessed. Casein hydrolysate application to cuttings of black poplar (Populus nigra) and Scouler's willow (Salix scouleriana) reduced browsing of these highly preferred species and promoted a marked increase in browsing of tamarisk (Tamarix ramosissima). These results suggest that casein hydrolysate treatment of desirable riparian plant species such as Salix and Populus may promote beaver foraging of invasive tamarisk.

Effect of submergence-emergence sequence and organic matter or aluminosilicate amendment on metal uptake by woody wetland plant species from contaminated sediments

International Nuclear Information System (INIS)

Vandecasteele, Bart; Du Laing, Gijs; Tack, Filip M.G.

2007-01-01

Site-specific hydrological conditions affect the availability of trace metals for vegetation. In a greenhouse experiment, the effect of submersion on the metal uptake by the wetland plant species Salix cinerea and Populus nigra grown on a contaminated dredged sediment-derived soil and on an uncontaminated soil was evaluated. An upland hydrological regime for the polluted sediment caused elevated Cd concentrations in leaves and cuttings for both species. Emergence and soil oxidation after initial submersion of a polluted sediment resulted in comparable foliar Cd and Zn concentrations for S. cinerea as for the constant upland treatment. The foliar Cd and Zn concentrations were clearly higher than for submerged soils after initial upland conditions. These results point at the importance of submergence-emergence sequence for plant metal availability. The addition of foliar-based organic matter or aluminosilicates to the polluted sediment-derived soil in upland conditions did not decrease Cd and Zn uptake by S. cinerea. - The effect of a wetland hydrological regime on Cd uptake was similar for Populus nigra and Salix cinerea

Characterization and reactions of a Salix extractive with a unique ring system

Science.gov (United States)

Lawrence Landucci; Sally Ralph; Kolby Hirth

2003-01-01

An extractive compound with a novel ring system was isolated from the wood of Salix alba and was given the name Salucci. The compound was primarily identified from the 1D NMR, 2D NMR and LC-MSMS data and the structure investigated through reactions and derivatizations.

Comparative genomic analysis of the WRKY III gene family in populus, grape, arabidopsis and rice.

Science.gov (United States)

Wang, Yiyi; Feng, Lin; Zhu, Yuxin; Li, Yuan; Yan, Hanwei; Xiang, Yan

2015-09-08

WRKY III genes have significant functions in regulating plant development and resistance. In plant, WRKY gene family has been studied in many species, however, there still lack a comprehensive analysis of WRKY III genes in the woody plant species poplar, three representative lineages of flowering plant species are incorporated in most analyses: Arabidopsis (a model plant for annual herbaceous dicots), grape (one model plant for perennial dicots) and Oryza sativa (a model plant for monocots). In this study, we identified 10, 6, 13 and 28 WRKY III genes in the genomes of Populus trichocarpa, grape (Vitis vinifera), Arabidopsis thaliana and rice (Oryza sativa), respectively. Phylogenetic analysis revealed that the WRKY III proteins could be divided into four clades. By microsynteny analysis, we found that the duplicated regions were more conserved between poplar and grape than Arabidopsis or rice. We dated their duplications by Ks analysis of Populus WRKY III genes and demonstrated that all the blocks were formed after the divergence of monocots and dicots. Strong purifying selection has played a key role in the maintenance of WRKY III genes in Populus. Tissue expression analysis of the WRKY III genes in Populus revealed that five were most highly expressed in the xylem. We also performed quantitative real-time reverse transcription PCR analysis of WRKY III genes in Populus treated with salicylic acid, abscisic acid and polyethylene glycol to explore their stress-related expression patterns. This study highlighted the duplication and diversification of the WRKY III gene family in Populus and provided a comprehensive analysis of this gene family in the Populus genome. Our results indicated that the majority of WRKY III genes of Populus was expanded by large-scale gene duplication. The expression pattern of PtrWRKYIII gene identified that these genes play important roles in the xylem during poplar growth and development, and may play crucial role in defense to drought

Phytoremediation of landfill leachate using Populus

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Richard B. Hall; Bart Sexton

2006-01-01

Proper genotype selection is required for successful phytoremediation. We selected eight Populus clones (NC13460, NC14018, DM115, NC14104, NC14106, DN5, NM2, NM6) of four genomic groups after three cycles of phyto-recurrent selection for a field trial that began June 2005 at the Oneida County Landfill in Rhinelander, WI, USA.

Biomass and genotype × environment interactions of Populus energy crops in the midwestern United States

Science.gov (United States)

Ronald S., Jr. Zalesny; Richard B. Hall; Jill A. Zalesny; Bernard G. McMahon; William E. Berguson; Glen R. Stanosz

2009-01-01

Using Populus feedstocks for biofuels, bioenergy, and bioproducts is becoming economically feasible as global fossil fuel prices increase. Maximizing Populus biomass production across regional landscapes largely depends on understanding genotype × environment interactions, given broad genetic variation at strategic (...

Patterns of genetic diversity and differentiation in resistance gene clusters of two hybridizing European Populus species

OpenAIRE

Casey, Céline; Stölting, Kai N.; Barbará, Thelma; González-Martínez, Santiago C.; Lexer, Christian

2015-01-01

Resistance genes (R-genes) are essential for long-lived organisms such as forest trees, which are exposed to diverse herbivores and pathogens. In short-lived model species, R-genes have been shown to be involved in species isolation. Here, we studied more than 400 trees from two natural hybrid zones of the European Populus species Populus alba and Populus tremula for microsatellite markers located in three R-gene clusters, including one cluster situated in the incipient sex chromosome region....

Het geslacht Populus in verband met zijn beteekenis voor de houtteelt = The genus populus and its significance in silviculture

NARCIS (Netherlands)

Houtzagers, G.

1937-01-01

The genus Populus L. can be divided into 5 sections. This study deals with the classification and description of the species and varieties of the section Aigeiros Duby (black poplars), which contains almost all the important cultivated types in the Netherlands. The botanical information was

Kinetic modeling of batch fermentation for Populus hydrolysate tolerant mutant and wild type strains of Clostridium thermocellum.

Science.gov (United States)

Linville, Jessica L; Rodriguez, Miguel; Mielenz, Jonathan R; Cox, Chris D

2013-11-01

The extent of inhibition of two strains of Clostridium thermocellum by a Populus hydrolysate was investigated. A Monod-based model of wild type (WT) and Populus hydrolysate tolerant mutant (PM) strains of the cellulolytic bacterium C. thermocellum was developed to quantify growth kinetics in standard media and the extent of inhibition to a Populus hydrolysate. The PM was characterized by a higher growth rate (μmax=1.223 vs. 0.571 h(-1)) and less inhibition (KI,gen=0.991 vs. 0.757) in 10% v/v Populus hydrolysate compared to the WT. In 17.5% v/v Populus hydrolysate inhibition of PM increased slightly (KI,gen=0.888), whereas the WT was strongly inhibited and did not grow in a reproducible manner. Of the individual inhibitors tested, 4-hydroxybenzoic acid was the most inhibitory, followed by galacturonic acid. The PM did not have a greater ability to detoxify the hydrolysate than the WT. Copyright © 2013 Elsevier Ltd. All rights reserved.

Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0)

Science.gov (United States)

2010-05-01

monophylla or P. edulis), junipers (Juniperus), cottonwoods (e.g., Populus fremontii), willows (Salix), or hardwoods (e.g., Quercus , Platanus...pine in association with incense cedar and California black oak ( Quercus kelloggii) on the western slopes and Jeffrey pine on the eastern slopes...corkbark fir (Abies lasiocarpa var. arizonica ), limber pine (Pinus flexilis), and bristlecone pine (P. aristata) (Bailey 1995). Black Hills (MLRA

Efficient Agrobacterium-Mediated Transformation of Hybrid Poplar Populus davidiana Dode × Populus bollena Lauche

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Xue Han

2013-01-01

Full Text Available Poplar is a model organism for high in vitro regeneration in woody plants. We have chosen a hybrid poplar Populus davidiana Dode × Populus bollena Lauche. By optimizing the Murashige and Skoog medium with (0.3 mg/L 6-benzylaminopurine and (0.08 mg/L naphthaleneacetic acid, we have achieved the highest frequency (90% for shoot regeneration from poplar leaves. It was also important to improve the transformation efficiency of poplar for genetic breeding and other applications. In this study, we found a significant improvement of the transformation frequency by controlling the leaf age. Transformation efficiency was enhanced by optimizing the Agrobacterium concentration (OD600 = 0.8–1.0 and an infection time (20–30 min. According to transmission electron microscopy observations, there were more Agrobacterium invasions in the 30-day-old leaf explants than in 60-day-old and 90-day-old explants. Using the green fluorescent protein (GFP marker, the expression of MD–GFP fusion proteins in the leaf, shoot, and root of hybrid poplar P. davidiana Dode × P. bollena Lauche was visualized for confirmation of transgene integration. Southern and Northern blot analysis also showed the integration of T-DNA into the genome and gene expression of transgenic plants. Our results suggest that younger leaves had higher transformation efficiency (~30% than older leaves (10%.

Multiple factors affect pest and pathogen damage on 31 Populus clones in South Carolina

Science.gov (United States)

David R. Coyle; Mark D. Coleman; Jaclin A. Durant; Lee A. Newman

2006-01-01

Populus species and hybrids have many practical applications, but there is a paucity of data regarding selections that perform well in the southeastern US. We compared pest susceptibility of 31 Populus clones over 3 years in South Carolina, USA. Cuttings were planted in spring 2001 on two study sites. Clones planted in the...

Isolation of Secondary Metabolites from the Roots of Salix Babylonica

Science.gov (United States)

Singh, Harpreet; Raturi, Rakesh; Badoni, P. P.

2017-08-01

Chemical examination of ethanolic extract of Salix babylonica, root, led to isolation of 2-(Hydroxymethyl) phenyl β-D-glucopyranoside(1) and 2-[(benzoyloxy)methyl]-4-hydroxyphenyl β-D-glucopyranoside 3-Benzoate (2)with previously known compounds β-Sitosterol, kaempferol 7-O-glucoside andapigenin 7-O-galactoside. Compounds 1and 2 had been isolated for the first time from this plant. The structures of the compounds had been elucidated with the help of spectral and chemical studies.

A New Flavonoid Glycoside from Salix denticulata Aerial Parts

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Amita Bamola

2009-09-01

Full Text Available Abstract: A new flavonoid glycoside (1 has been isolated from the aerial parts of Salix denticulata (Salicaceae together with five known compounds, β-sitosterol, 2,6-dihydroxy- 4-methoxy acetophenone, eugenol-1-O-β-D-glucopyranoside, 1-O-β-D-(3’-benzoyl salicyl alcohol and luteolin-7-O-β-D-glucopyranosyl-(1-6-glucopyranoside. The structure of 1 was elucidated as 2’,5-dihydroxy-3’-methoxyflavone-7-O-β-D-glucopyranoside by means of chemical and spectral data including 2D NMR studies.

Insertional mutagenesis in Populus: relevance and feasibility

Science.gov (United States)

Victor Busov; Matthias Fladung; Andrew Groover; Steven Strauss

2005-01-01

The recent sequencing of the first tree genome, that of the black cottonwood (Populus trichocarpa), opens a new chapter in tree functional genomics. While the completion of the genome is a milestone, mobilizing this significant resource for better understanding the growth and development of woody perennials will be an even greater undertaking in the...

Environmental Assessment: Permanent Western United States C-17 Landing Zone

Science.gov (United States)

2008-09-01

Salix sp., Populus sp., Lemna minor , Cyperus sp. Delta Green Ground Beetle The Delta Green Ground Beetle, Elaphrus viridis Horn, 1878 is a...and the SCLA. Cumulative impacts can result from individually minor but collectively significant actions taking place over a period of time. None of...environmental effects on adjacent populations. Therefore, no disproportionately high and adverse effects will occur to minority and low-income

Micropropagation, genetic engineering, and molecular biology of Populus

Science.gov (United States)

N. B. Klopfenstein; Y. W. Chun; M. -S. Kim; M. A. Ahuja; M. C. Dillon; R. C. Carman; L. G. Eskew

1997-01-01

Thirty-four Populus biotechnology chapters, written by 85 authors, are comprised in 5 sections: 1) in vitro culture (micropropagation, somatic embryogenesis, protoplasts, somaclonal variation, and germplasm preservation); 2) transformation and foreign gene expression; 3) molecular biology (molecular/genetic characterization); 4) biotic and abiotic resistance (disease,...

Identification of Quantitative Trait Loci (QTL) and Candidate Genes for Cadmium Tolerance in Populus

Energy Technology Data Exchange (ETDEWEB)

Induri, Brahma R [West Virginia University; Ellis, Danielle R [West Virginia University; Slavov, Gancho [West Virginia University; Yin, Tongming [ORNL; Muchero, Wellington [ORNL; Tuskan, Gerald A [ORNL; DiFazio, Stephen P [West Virginia University

2012-01-01

Knowledge of genetic variation in response of Populus to heavy metals like cadmium (Cd) is an important step in understanding the underlying mechanisms of tolerance. In this study, a pseudo-backcross pedigree of Populus trichocarpa and Populus deltoides was characterized for Cd exposure. The pedigree showed significant variation for Cd tolerance thus enabling the identification of relatively tolerant and susceptible genotypes for intensive characterization. A total of 16 QTLs at logarithm of odds (LOD) ratio > 2.5, were found to be associated with total dry weight, its components, and root volume. Four major QTLs for total dry weight were mapped to different linkage groups in control (LG III) and Cd conditions (LG XVI) and had opposite allelic effects on Cd tolerance, suggesting that these genomic regions were differentially controlled. The phenotypic variation explained by Cd QTL for all traits under study varied from 5.9% to 11.6% and averaged 8.2% across all QTL. Leaf Cd contents also showed significant variation suggesting the phytoextraction potential of Populus genotypes, though heritability of this trait was low (0.22). A whole-genome microarray study was conducted by using two genotypes with extreme responses for Cd tolerance in the above study and differentially expressed genes were identified. Candidate genes including CAD2 (CADMIUM SENSITIVE 2), HMA5 (HEAVY METAL ATPase5), ATGTST1 (Arabidopsis thaliana Glutathione S-Transferase1), ATGPX6 (Glutathione peroxidase 6), and ATMRP 14 (Arabidopsis thaliana Multidrug Resistance associated Protein 14) were identified from QTL intervals and microarray study. Functional characterization of these candidate genes could enhance phytoremediation capabilities of Populus.

VOC emissions and carbon balance of two bioenergy plantations in response to nitrogen fertilization: A comparison of Miscanthus and Salix.

Science.gov (United States)

Hu, Bin; Jarosch, Ann-Mareike; Gauder, Martin; Graeff-Hönninger, Simone; Schnitzler, Jörg-Peter; Grote, Rüdiger; Rennenberg, Heinz; Kreuzwieser, Jürgen

2018-06-01

Energy crops are an important renewable source for energy production in future. To ensure high yields of crops, N fertilization is a common practice. However, knowledge on environmental impacts of bioenergy plantations, particularly in systems involving trees, and the effects of N fertilization is scarce. We studied the emission of volatile organic compounds (VOC), which negatively affect the environment by contributing to tropospheric ozone and aerosols formation, from Miscanthus and willow plantations. Particularly, we aimed at quantifying the effect of N fertilization on VOC emission. For this purpose, we determined plant traits, photosynthetic gas exchange and VOC emission rates of the two systems as affected by N fertilization (0 and 80 kg ha -1 yr -1 ). Additionally, we used a modelling approach to simulate (i) the annual VOC emission rates as well as (ii) the OH . reactivity resulting from individual VOC emitted. Total VOC emissions from Salix was 1.5- and 2.5-fold higher compared to Miscanthus in non-fertilized and fertilized plantations, respectively. Isoprene was the dominating VOC in Salix (80-130 μg g -1 DW h -1 ), whereas it was negligible in Miscanthus. We identified twenty-eight VOC compounds, which were released by Miscanthus with the green leaf volatile hexanal as well as dimethyl benzene, dihydrofuranone, phenol, and decanal as the dominant volatiles. The pattern of VOC released from this species clearly differed to the pattern emitted by Salix. OH . reactivity from VOC released by Salix was ca. 8-times higher than that of Miscanthus. N fertilization enhanced stand level VOC emissions, mainly by promoting the leaf area index and only marginally by enhancing the basal emission capacity of leaves. Considering the higher productivity of fertilized Miscanthus compared to Salix together with the considerably lower OH . reactivity per weight unit of biomass produced, qualified the C 4 -perennial grass Miscanthus as a superior source of future

EFFECT OF TEMPERATURE ON THE BIOLOGY OF TUBEROLACHNUS SALIGNUS (GMELIN (STERNORRHYNCHA: APHIDIDAE ON (SALIX ALBA

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Nıhal ÖZDER

2008-07-01

Full Text Available The development time, survivoship and reproduction of Tuberolachnus salignus (Gmelin( Lachninae: Lachnini were studied on Salix alba at fi ve constant temperatures (17.5°C, 20°C, 22.5°C, 25°C and 27.5°C . The developmental time of immature stages ranged from 17.00 days at 17.5°C to 12.21 days at 25°C on Salix alba. The total percentage of survivorship of immature stages varied from 50% and 70% 17.5°C -20°C on S. alba. The largest r m valueoccurred with 0.2540 at 20°C on S. alba. The mean generation time of the population ranged from 13.595 days at 22.5°C to 19.60 days at 17.5°C on S. alba. The optimal temperature for Tuberolachnus salignus was 20°C.

DETERMINATION OF FLAVONOIDS OF WILLOW TRIANDRA (SALIX TRIANDRA L., GROWING IN THE NORTH CAUCASUS

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E. G. Sannikova

2016-01-01

Full Text Available Plants of willow genus are rich in various flavonoids. In 60-e years of the XX century the works of V. A. Kompantsev showed that leaves of willow triandra, growing in the North Caucasus, contain up to 5% of rutin. The method, which required long sample preparation (extraction of the raw material with TLC, chromatographic layer extraction with methanol, removal of the solvent, dissolution in ethanol, optical density measurements was used. Currently available and simple methods for the determination of rutin in plant material are described. Given that leaves of Salix triandra contain significant amounts of rutin and can be a potential raw material for the creation of medicines on their basis, it is essential to determine the amount of flavonoids in the leaves of Salix triandra and its branches.The purpose of this study is determination of the amount of flavonoids in the willow triandra, growing in the North Caucasus, depending on the place and time of collection.Methods. TLC and the method of differential spectrophotometry were used to study chemical reactions. Results. The presence of flavonoids in various vegetative plant organs was established using qualitative reactions (cyanidin test; boric-citric reaction; the reaction with solution of lead acetate and solution of ammonia. Rutin and quercetin flavonoids in the presence of standard samples were identified using TLC. the method of differential spectrophotometry, based on the reaction of flavonoids with aluminum chloride was used for the quantitative determination of the amount of flavonoids. It is shown that the greatest quantity of flavonoids amount accumulated in the leaves (up to 3.76%, its value in branches is slightly smaller (up to 3.26%. The branches without leaves have almost 10 times less flavonoids. It was established experimentally that the accumulation of flavonoids in raw material of Salix triandra is dependent on the place and time of

The root anchorage ability of Salix alba var. tristis using a pull-out test

African Journals Online (AJOL)

user

2011-11-21

Nov 21, 2011 ... In the last few years, Beijing Forestry University (China) and the University of Natural Resources and applied Life. Sciences (Austria) have examined the suitabilities and capabilities of soil bioengineering techniques under the local condition of Beijing. One of the plant species used was Salix alba var. tristis.

A genetic linkage map of willow (Salix viminalis) based on AFLP and microsatelite markers

NARCIS (Netherlands)

Hanley, S.; Barker, J.H.A.; Ooijen, van J.W.; Aldam, C.; Harris, S.L.; Ahman, I.; Larsson, S.; Karp, A.

2002-01-01

The genus Salix (willow) contains a number of species of great value as biomass crops. Efforts to breed varieties with improved biomass yields and resistances to pests and diseases are limited by the lack of knowledge on the genetic basis of the traits. We have used AFLP and microsatellite markers

Effects of Clone, Silvicultural, and Miticide Treatments on Cottonwood Leafcurl Mite (Acari: Eriophyidae) Damage in Plantation Populus

Science.gov (United States)

David R. Coyle

2002-01-01

Aculops lobuliferus (Keifer) is a little known pest of plantation Populus spp., which is capable of causing substantial damage. This is the First documented occurrence of A. lobuliferus in South Carolina. Previous anecdotal data indicated clonal variation in Populus susceptibility to A...

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

Science.gov (United States)

Tian, Feng-Xia; Zang, Jian-Lei; Wang, Tan; Xie, Yu-Li; Zhang, Jin; Hu, Jian-Jun

2015-01-01

Aldehyde dehydrogenases (ALDHs) constitute a superfamily of NAD(P)+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

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Feng-Xia Tian

Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

Genetic analysis of post-mating reproductive barriers in hybridizing European Populus species.

Science.gov (United States)

Macaya-Sanz, D; Suter, L; Joseph, J; Barbará, T; Alba, N; González-Martínez, S C; Widmer, A; Lexer, C

2011-10-01

Molecular genetic analyses of experimental crosses provide important information on the strength and nature of post-mating barriers to gene exchange between divergent populations, which are topics of great interest to evolutionary geneticists and breeders. Although not a trivial task in long-lived organisms such as trees, experimental interspecific recombinants can sometimes be created through controlled crosses involving natural F(1)'s. Here, we used this approach to understand the genetics of post-mating isolation and barriers to introgression in Populus alba and Populus tremula, two ecologically divergent, hybridizing forest trees. We studied 86 interspecific backcross (BC(1)) progeny and >350 individuals from natural populations of these species for up to 98 nuclear genetic markers, including microsatellites, indels and single nucleotide polymorphisms, and inferred the origin of the cytoplasm of the cross with plastid DNA. Genetic analysis of the BC(1) revealed extensive segregation distortions on six chromosomes, and >90% of these (12 out of 13) favored P. tremula donor alleles in the heterospecific genomic background. Since selection was documented during early diploid stages of the progeny, this surprising result was attributed to epistasis, cyto-nuclear coadaptation, heterozygote advantage at nuclear loci experiencing introgression or a combination of these. Our results indicate that gene flow across 'porous' species barriers affects these poplars and aspens beyond neutral, Mendelian expectations and suggests the mechanisms responsible. Contrary to expectations, the Populus sex determination region is not protected from introgression. Understanding the population dynamics of the Populus sex determination region will require tests based on natural interspecific hybrid zones.

Recreational Appendix Report, Elm Fork Flood Control Project, Dallas and Denton Counties, Texas.

Science.gov (United States)

1973-05-01

Juniperus virginiana 2. Willow Salix nigra 3. Cottonwood Populus deltoides 4. Black Walnut Juglans migra 5. Pecan Carya illinoensis 6. Bur Oak...Maclura pomifera 12. Red Mulberry Morus rubra 13. Sycamore Platanus occidentailis 14. Red Haw Crataegus, sps. 15. Wild Plum Prunus mexicana 16. Mesquite...also provides a habitat for a number of mammals including: 1. Opossum Didelphis virginiana 2. Shrews Blarina brevicuada and Cryptotis parva 3. Raccoon

Glycosylation-mediated phenylpropanoid partitioning in Populus tremuloides cell cultures

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Babst Benjamin A

2009-12-01

Full Text Available Abstract Background Phenylpropanoid-derived phenolic glycosides (PGs and condensed tannins (CTs comprise large, multi-purpose non-structural carbon sinks in Populus. A negative correlation between PG and CT concentrations has been observed in several studies. However, the molecular mechanism underlying the relationship is not known. Results Populus cell cultures produce CTs but not PGs under normal conditions. Feeding salicyl alcohol resulted in accumulation of salicins, the simplest PG, in the cells, but not higher-order PGs. Salicin accrual reflected the stimulation of a glycosylation response which altered a number of metabolic activities. We utilized this suspension cell feeding system as a model for analyzing the possible role of glycosylation in regulating the metabolic competition between PG formation, CT synthesis and growth. Cells accumulated salicins in a dose-dependent manner following salicyl alcohol feeding. Higher feeding levels led to a decrease in cellular CT concentrations (at 5 or 10 mM, and a negative effect on cell growth (at 10 mM. The competition between salicin and CT formation was reciprocal, and depended on the metabolic status of the cells. We analyzed gene expression changes between controls and cells fed with 5 mM salicyl alcohol for 48 hr, a time point when salicin accumulation was near maximum and CT synthesis was reduced, with no effect on growth. Several stress-responsive genes were up-regulated, suggestive of a general stress response in the fed cells. Salicyl alcohol feeding also induced expression of genes associated with sucrose catabolism, glycolysis and the Krebs cycle. Transcript levels of phenylalanine ammonia lyase and most of the flavonoid pathway genes were reduced, consistent with down-regulated CT synthesis. Conclusions Exogenous salicyl alcohol was readily glycosylated in Populus cell cultures, a process that altered sugar utilization and phenolic partitioning in the cells. Using this system, we

Evaluation of the phytoremediation potential of the Salix caprea in tailing ponds

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Anca MIHALY-COZMUTA

2009-05-01

Full Text Available The goat willow (Salix caprea belongs to the typical pioneer vegetation at former ore mining sites in East and Middle Europe as a result of its high metal-tolerance. Ectomycorrhizal (EM fungi are known to contribute essentially to the tolerance of plants against abiotic stress. We have determined the absorption/ accretion potential of the goat willow related to heavy metals, as well as the growth rhythm of this species in conditions offered by polluted sites, correlated to the presence/ absence of the microbiota in the soil attached to the root. The research unravels how the goat willow (Salix caprea, as a native species can be used in remediation actions of polluted sites based on its high adaptive potential, as well as on its capacity to absorb and accumulate heavy metals. In terms of survival strategy, mycorhrised fungi attached to the polluted soil play a significant part, since they induce plants a certain resistance by diminishing the absorption of heavy metals by the host plant. We suppose that the majority of EM associations of S. caprea, in combination with high portions of metal-chelating organic acids containing fungal partners, contributes essentially to the high tolerance of this species against high metal concentrations in the soil.

Successful grafting in poplar species (Populus spp.) breeding

Science.gov (United States)

A. Assibi Mahama; Brian Sparks; Ronald S., Zalesny; Richard B. Hall

2006-01-01

Poor rooting of Populus deltoides Bartr. ex Marsh hardwood cuttings often has contributed to delays in breeding progress as a result of failures of scion wood before and/or after pollination. Seventeen clones were used, and the study was conducted in the greenhouse to test an "intervenous feeding" (IV) method, along with three different...

Transcriptomic Response of Purple Willow (Salix purpurea to Arsenic Stress

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Aymeric Yanitch

2017-06-01

Full Text Available Arsenic (As is a toxic element for plants and one of the most common anthropogenic pollutants found at contaminated sites. Despite its severe effects on plant metabolism, several species can accumulate substantial amounts of arsenic and endure the associated stress. However, the genetic mechanisms involved in arsenic tolerance remains obscure in many model plant species used for land decontamination (phytoremediation, including willows. The present study assesses the potential of Salix purpurea cv. ‘Fish Creek’ for arsenic phytoextraction and reveals the genetic responses behind arsenic tolerance, phytoextraction and metabolism. Four weeks of hydroponic exposure to 0, 5, 30 and 100 mg/L revealed that plants were able to tolerate up to 5 mg/L arsenic. Concentrations of 0 and 5 mg/L of arsenic treatment were then used to compare alterations in gene expression of roots, stems and leaves using RNA sequencing. Differential gene expression revealed transcripts encoding proteins putatively involved in entry of arsenic into the roots, storage in vacuoles and potential transport through the plant as well as primary and secondary (indirect toxicity tolerance mechanisms. A major role for tannin as a compound used to relieve cellular toxicity is implicated as well as unexpected expression of the cadmium transporter CAX2, providing a potential means for internal arsenic mobility. These insights into the underpinning genetics of a successful phytoremediating species present novel opportunities for selection of dedicated arsenic tolerant crops as well as the potential to integrate such tolerances into a wider Salix ideotype alongside traits including biomass yield, biomass quality, low agricultural inputs and phytochemical production.

Transcriptomic Response of Purple Willow (Salix purpurea) to Arsenic Stress

Science.gov (United States)

Yanitch, Aymeric; Brereton, Nicholas J. B.; Gonzalez, Emmanuel; Labrecque, Michel; Joly, Simon; Pitre, Frederic E.

2017-01-01

Arsenic (As) is a toxic element for plants and one of the most common anthropogenic pollutants found at contaminated sites. Despite its severe effects on plant metabolism, several species can accumulate substantial amounts of arsenic and endure the associated stress. However, the genetic mechanisms involved in arsenic tolerance remains obscure in many model plant species used for land decontamination (phytoremediation), including willows. The present study assesses the potential of Salix purpurea cv. ‘Fish Creek’ for arsenic phytoextraction and reveals the genetic responses behind arsenic tolerance, phytoextraction and metabolism. Four weeks of hydroponic exposure to 0, 5, 30 and 100 mg/L revealed that plants were able to tolerate up to 5 mg/L arsenic. Concentrations of 0 and 5 mg/L of arsenic treatment were then used to compare alterations in gene expression of roots, stems and leaves using RNA sequencing. Differential gene expression revealed transcripts encoding proteins putatively involved in entry of arsenic into the roots, storage in vacuoles and potential transport through the plant as well as primary and secondary (indirect) toxicity tolerance mechanisms. A major role for tannin as a compound used to relieve cellular toxicity is implicated as well as unexpected expression of the cadmium transporter CAX2, providing a potential means for internal arsenic mobility. These insights into the underpinning genetics of a successful phytoremediating species present novel opportunities for selection of dedicated arsenic tolerant crops as well as the potential to integrate such tolerances into a wider Salix ideotype alongside traits including biomass yield, biomass quality, low agricultural inputs and phytochemical production. PMID:28702037

Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species.

Science.gov (United States)

Du, Shuhui; Wang, Zhaoshan; Ingvarsson, Pär K; Wang, Dongsheng; Wang, Junhui; Wu, Zhiqiang; Tembrock, Luke R; Zhang, Jianguo

2015-10-01

Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P. tremula and P. davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P. tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles in the formation of the disjunct distributions and divergence of these three Populus species. © 2015 John Wiley & Sons Ltd.

Genome-Wide Analysis of a TaLEA-Introduced Transgenic Populus simonii × Populus nigra Dwarf Mutant

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Jing Jiang

2012-03-01

Full Text Available A dwarf mutant (dwf1 was obtained among 15 transgenic lines, when TaLEA (Tamarix androssowii late embryogenesis abundant gene was introduced into Populus simonii × Populus nigra by Agrobacterium tumefaciens-mediated transformation. Under the same growth conditions, dwf1 height was significantly reduced compared with the wild type and the other transgenic lines. Because only one transgenic line (dwf1 displayed the dwarf phenotype, we considered that T-DNA insertion sites may play a role in the mutant formation. The mechanisms underlying this effect were investigated using TAIL-PCR (thermal asymmetric interlaced PCR and microarrays methods. According to the TAIL-PCR results, two flanking sequences located on chromosome IV and VIII respectively, were cloned. The results indicated the integration of two independent T-DNA copies. We searched for the potential genes near to the T-DNA insertions. The nearest gene was a putative poplar AP2 transcription factor (GI: 224073210. Expression analysis showed that AP2 was up-regulated in dwf1 compared with the wild type and the other transgenic lines. According to the microarrays results, a total of 537 genes involved in hydrolase, kinase and transcription factor activities, as well as protein and nucleotide binding, showed significant alterations in gene expression. These genes were expressed in more than 60 metabolic pathways, including starch, sucrose, galactose and glycerolipid metabolism and phenylpropanoids and flavonoid biosyntheses. Our transcriptome and T-DNA insertion sites analyses might provide some useful insights into the dwarf mutant formation.

Indução de calos friáveis em explantes foliares de Salix (Salyx humboldtiana Willd Induction of friable callus in leaf explants of Salix (Salyx humboldtiana Willd

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Breno Régis Santos

2005-06-01

Full Text Available O salix é uma árvore ornamental adaptada a terrenos úmidos, sendo considerada uma espécie importante para a recomposição de áreas ciliares degradadas. A madeira pode ser empregada na indústria em geral. Apesar de produzir grande quantidade de sementes, estas não possuem alta percentagem de germinação. O presente trabalho teve como objetivo realizar o estabelecimento in vitro de salix através da indução e formação de calos friáveis em explantes foliares, visando a uma posterior regeneração de plantas para a propagação massal desta espécie. Explantes foliares foram inoculados em meio de cultura MS (MURASHIGE & SKOOG, 1962, acrescido de diferentes concentrações de ácido 2,4-diclorofenoxiacético (0; 1,0; 2,0; 4,0; 6,0; 8,0; 10,0 e 12,0mg L-1 e combinações entre ácido naftalenoacético e benzilaminopurina, ambos em concentrações de 0,0; 1,0; 2,0; 4,0; 6,0 e 8,0mg L-1. Os resultados demonstram que explantes inoculados na ausência de reguladores de crescimento não apresentam a formação de calos friáveis. Significativa produção de calos friáveis (90% é obtida utilizando-se 6,0mg L-1 de ácido 2,4-diclorofenoxiacético. A utilização de concentração individual de ácido naftalenoacético ou benzilaminopurina, além de induzir a calogênese também foi capaz de promover rizogênese.Salix is an ornamental tree adapted to humid soils being considered an important species used in depleted areas. Its wood may be used in all kinds of industries. Although the production of seeds is large, the germination is reduced. The objective of this work was to establish salix in vitro through the induction and formation of friable callus of leaf explants to provide future regeneration of plants for mass propagation of the species. Leaf explants were inoculated in MS medium (MURASHIGE & SKOOG, 1962 supplemented with different concentrations of 2-4-diclorofenoxiacetic acid (0; 1.0; 2.0; 4.0; 6.0; 8.0 and 12.0mg L-1 and combinations

Diversification and expression of the PIN, AUX/LAX and ABCB families of putative auxin transporters in Populus

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Nicola eCarraro

2012-02-01

Full Text Available Intercellular transport of the plant hormone auxin is mediated by three families of membrane-bound protein carriers, with the PIN and ABCB families coding primarily for efflux proteins and the AUX/LAX family coding for influx proteins. In the last decade our understanding of gene and protein function for these transporters in Arabidopsis has expanded rapidly but very little is known about their role in woody plant development. Here we present a comprehensive account of all three families in the model woody species Populus, including chromosome distribution, protein structure, quantitative gene expression, and evolutionary relationships. The PIN and AUX/LAX gene families in Populus comprise 16 and 8 members respectively, and show evidence for the retention of paralogs following a relatively recent whole genome duplication. There is also evidence for differential expression across tissues within many gene pairs. The ABCB family is previously undescribed in Populus and includes 20 members, showing a much deeper evolutionary history including both tandem and whole genome duplication as well as probable loss. A striking number of these transporters are expressed in developing Populus stems and we suggest that evolutionary and structural relationships with known auxin transporters in Arabidopsis can point toward candidate genes for further study in Populus. This is especially important for the ABCBs, which is a large family and includes members in Arabidopsis that are able to transport other substrates in addition to auxin. Protein modeling, sequence alignment and expression data all point to ABCB1.1 as a likely auxin transport protein in Populus. Given that basipetal auxin flow through the cambial zone shapes the development of woody stems, it is important that we identify the full complement of proteins involved in this process. This work should lay the foundation for studies targeting specific proteins for functional characterization and in situ

The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

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Rytter, Rose-Marie

2013-09-01

The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots water availability. Fine root production (treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

Creation and genomic analysis of irradiation hybrids in Populus

Science.gov (United States)

Matthew S. Zinkgraf; K. Haiby; M.C. Lieberman; L. Comai; I.M. Henry; Andrew Groover

2016-01-01

Establishing efficient functional genomic systems for creating and characterizing genetic variation in forest trees is challenging. Here we describe protocols for creating novel gene-dosage variation in Populus through gamma-irradiation of pollen, followed by genomic analysis to identify chromosomal regions that have been deleted or inserted in...

Tratamiento de un efluente textil mediante electrooxidación-Salix babylonica

OpenAIRE

Sánchez Sánchez, Hilda Alejandra

2016-01-01

A nivel mundial, la industria textil es considerada una de las principales fuentes de descarga que afectan la calidad del agua debido al gran volumen que emplea en sus procesos y al uso de una amplia gama de colorantes sintéticos. En esta investigación se evaluó el tratamiento de un agua residual textil mediante un sistema acoplado de electrooxidación-Salix babylonica usando electrodos DDB. En el estudio, se construyó una celda electroquímica en batch, utilizando 5 electrodos paralelos vertic...

Trinucleotide repeat microsatellite markers for Black Poplar (Populus nigra L.)

NARCIS (Netherlands)

Smulders, M.J.M.; Schoot, van der J.; Arens, P.; Vosman, B.

2001-01-01

Using an enrichment procedure, we have cloned microsatellite repeats from black poplar (Populus nigra L.) and developed primers for microsatellite marker analysis. Ten primer pairs, mostly for trinucleotide repeats, produced polymorphic fragments in P. nigra. Some of them also showed amplification

Sulfur-aided phytoextraction of Cd and Zn by Salix smithiana combined with in situ metal immobilization by gravel sludge and red mud

International Nuclear Information System (INIS)

Iqbal, Muhammad; Puschenreiter, Markus; Oburger, Eva; Santner, Jakob; Wenzel, Walter W.

2012-01-01

As phytoextraction implementation may be limited by metal toxicity and leaching, we investigated the idea of in situ metal immobilization in bulk soil, while increasing metal bioavailability in the rhizosphere. Salix smithiana was grown in a pot experiment on two Cd/Zn polluted soils. Treatments with or without willows included: no additives; gravel sludge + red mud kg −1 ; acidification with S to pH 3.5; and metal immobilization combined with soil acidification. Salix smithiana removed up to 0.78 ± 0.06% total Cd and 0.34% (±0.02) total Zn from the non-treated soils. The phytoextraction efficiency in the S treatments was enhanced by up to ∼50% in response to metal solubility that was magnified by reductive co-dissolution from Mn (IV) and Fe(III) (oxy)hydroxides during microbial S oxidation in the willow rhizosphere. The proposed technique proved to enhance phytoextraction efficiency while controlling the risk of metal leaching from the root zone and phytotoxicity. - Highlights: ► Phytoextraction of Cd and Zn using willow (Salix smithiana) was enhanced by elemental sulfur. ► Reductive metals dissolution by microbial S oxidation was magnified in the willow rhizosphere. ► Thus metal bioavailability was high at the location of uptake in the phytoextraction crop. ► Concurrent immobilization by soil amendments can reduce metal leaching from the bulk soil. - Magnified Cd and Zn availability in S-amended rhizosphere of Salix smithiana enhances shoot Cd/Zn removal while metal leaching from the root zone can be reduced by immobilizing soil amendments.

DETERMINATION OF RUTIN IN LEAVES OF SALIX TRIANDRA USING THE METHOD OF PLANAR CHROMATOGRAPHY

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E. G. Sannikova

2016-01-01

Full Text Available The aim of the study is to develop new methods of identification and quantitative determination of rutin in the leaves of Salix triandra L. with thin-layer chromatography. The digital processing of the chromatograms was performed using «Sorbfil Videodensitometer» computer program (Krasnodar. For the chromatography analysis we used plates «Sorbfil» PTSH-P-A-UV, mobile phase: n-butanol-glacial acetic acid-water (4:1:1, detecting reagent – ammonia vapors. The rutin is detected as yellow spots with Rf 0.64±0.02. The detection limit is 0.5 μg/μl. The regression equation has the form: S=4.75×103 m. With the use of this method we found that the composition of rutin in leaves of Salix triandra was in the range 1.81±0.06% on the air-dry raw material (relative standard deviation RSD%=2.5%; the measurement error E=3.12%. The method is sensitive, linear, has a small error, and does not require expensive equipment.

Differentiation of Populus species using chloroplast single nucleotide polymorphism (SNP) markers--essential for comprehensible and reliable poplar breeding.

Science.gov (United States)

Schroeder, H; Hoeltken, A M; Fladung, M

2012-03-01

Within the genus Populus several species belonging to different sections are cross-compatible. Hence, high numbers of interspecies hybrids occur naturally and, additionally, have been artificially produced in huge breeding programmes during the last 100 years. Therefore, determination of a single poplar species, used for the production of 'multi-species hybrids' is often difficult, and represents a great challenge for the use of molecular markers in species identification. Within this study, over 20 chloroplast regions, both intergenic spacers and coding regions, have been tested for their ability to differentiate different poplar species using 23 already published barcoding primer combinations and 17 newly designed primer combinations. About half of the published barcoding primers yielded amplification products, whereas the new primers designed on the basis of the total sequenced cpDNA genome of Populus trichocarpa Torr. & Gray yielded much higher amplification success. Intergenic spacers were found to be more variable than coding regions within the genus Populus. The highest discrimination power of Populus species was found in the combination of two intergenic spacers (trnG-psbK, psbK-psbl) and the coding region rpoC. In barcoding projects, the coding regions matK and rbcL are often recommended, but within the genus Populus they only show moderate variability and are not efficient in species discrimination. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Frost-related dieback of Swedish and Estonian Salix plantations due to pathogenic and ice nucleation-active bacteria

Energy Technology Data Exchange (ETDEWEB)

Cambours, M.A.

2004-07-01

During the past decade, important dieback has been observed in short-rotation forestry plantations of Salix viminalis and S. dasyclados in Sweden and Estonia, plantations from which the isolation of ice nucleation-active (INA) and pathogenic bacteria has also been reported. This thesis investigates the connection between bacterial infection and frost as a possible cause for such damage, and the role played by internal and external factors (e.g. plant frost sensitivity, fertilisation) in the dieback observed. Bacterial floras isolated from ten Salix clones growing on fertilised/unfertilised mineral soil or nitrogen-rich organic soil, were studied. Culturable bacterial communities present both in internal necrotic tissues and on the plant surface (i.e. epiphytes) were isolated on two occasions (spring and autumn). The strains were biochemically characterised (with gram, oxidase and fluorescence tests), and tested for ice nucleation-activity. Their pathogenic properties were studied with and without association to a freezing stress. Certain strains were eventually identified with BIOLOG plates and 16S rRNA analysis. A high number of culturable bacterial strains was found in the plant samplings, belonging mainly to Erwinia and Sphingomonas spp.; pathogenic and INA communities being mostly Erwinia-, Sphingomonas- and Xanthomonas-like. The generally higher plant dieback noted in the field on nutrient-rich soils and for frost sensitive clones was found connected to higher numbers of pathogenic and INA bacteria in the plants. We thus confirm Salix dieback to be related to a synergistic effect of frost and bacterial infection, possibly aggravated by fertilisation.

Preparation and Characterization of Lignocellulosic Oil Sorbent by Hydrothermal Treatment of Populus Fiber

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Yue Zhang

2014-09-01

Full Text Available This study is aimed at achieving the optimum conditions of hydrothermal treatment and acetylation of Populus fiber to improve its oil sorption capacity (OSC in an oil-water mixture. The characteristics of the hydrolyzed and acetylated fibers were comparatively investigated by FT-IR, CP-MAS 13C-NMR, SEM and TGA. The optimum conditions of the hydrothermal treatment and acetylation were obtained at170 °C for 1 h and 120 °C for 2 h, respectively. The maximum OSC of the hydrolyzed fiber (16.78 g/g was slightly lower than that of the acetylated fiber (21.57 g/g, but they were both higher than the maximum OSC of the unmodified fiber (3.94 g/g. In addition, acetylation after hydrothermal treatment for the Populus fiber was unnecessary as the increment of the maximum OSC was only 3.53 g/g. The hydrolyzed and the acetylated Populus fibers both displayed a lumen orifice enabling a high oil entrapment. The thermal stability of the modified fibers was shown to be increased in comparison with that of the raw fiber. The hydrothermal treatment offers a new approach to prepare lignocellulosic oil sorbent.

The Populus ARBORKNOX1 homeodomain transcription factor regulates woody growth through binding to evolutionarily conserved target genes of diverse function

Science.gov (United States)

Lijun Liu; Matthew S. Zinkgraf; H. Earl Petzold; Eric P. Beers; Vladimir Filkov; Andrew Groover

2014-01-01

The class I KNOX homeodomain transcription factor ARBORKNOX1 (ARK1) is a key regulator of vascular cambium maintenance and cell differentiation in Populus. Currently, basic information is lacking concerning the distribution, functional characteristics, and evolution of ARK1 binding in the Populus genome.

Phylogeny reconstruction and hybrid analysis of populus (Salicaceae) based on nucleotide sequences of multiple single-copy nuclear genes and plastid fragments.

Science.gov (United States)

Wang, Zhaoshan; Du, Shuhui; Dayanandan, Selvadurai; Wang, Dongsheng; Zeng, Yanfei; Zhang, Jianguo

2014-01-01

Populus (Salicaceae) is one of the most economically and ecologically important genera of forest trees. The complex reticulate evolution and lack of highly variable orthologous single-copy DNA markers have posed difficulties in resolving the phylogeny of this genus. Based on a large data set of nuclear and plastid DNA sequences, we reconstructed robust phylogeny of Populus using parsimony, maximum likelihood and Bayesian inference methods. The resulting phylogenetic trees showed better resolution at both inter- and intra-sectional level than previous studies. The results revealed that (1) the plastid-based phylogenetic tree resulted in two main clades, suggesting an early divergence of the maternal progenitors of Populus; (2) three advanced sections (Populus, Aigeiros and Tacamahaca) are of hybrid origin; (3) species of the section Tacamahaca could be divided into two major groups based on plastid and nuclear DNA data, suggesting a polyphyletic nature of the section; and (4) many species proved to be of hybrid origin based on the incongruence between plastid and nuclear DNA trees. Reticulate evolution may have played a significant role in the evolution history of Populus by facilitating rapid adaptive radiations into different environments.

Phylogeny reconstruction and hybrid analysis of populus (Salicaceae based on nucleotide sequences of multiple single-copy nuclear genes and plastid fragments.

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Zhaoshan Wang

Full Text Available Populus (Salicaceae is one of the most economically and ecologically important genera of forest trees. The complex reticulate evolution and lack of highly variable orthologous single-copy DNA markers have posed difficulties in resolving the phylogeny of this genus. Based on a large data set of nuclear and plastid DNA sequences, we reconstructed robust phylogeny of Populus using parsimony, maximum likelihood and Bayesian inference methods. The resulting phylogenetic trees showed better resolution at both inter- and intra-sectional level than previous studies. The results revealed that (1 the plastid-based phylogenetic tree resulted in two main clades, suggesting an early divergence of the maternal progenitors of Populus; (2 three advanced sections (Populus, Aigeiros and Tacamahaca are of hybrid origin; (3 species of the section Tacamahaca could be divided into two major groups based on plastid and nuclear DNA data, suggesting a polyphyletic nature of the section; and (4 many species proved to be of hybrid origin based on the incongruence between plastid and nuclear DNA trees. Reticulate evolution may have played a significant role in the evolution history of Populus by facilitating rapid adaptive radiations into different environments.

Genetic Modification of Lignin in Hybrid Poplar (Populus alba × Populus tremula) Does Not Substantially Alter Plant Defense or Arthropod Communities.

Science.gov (United States)

Buhl, Christine; Meilan, Richard; Lindroth, Richard L

2017-05-01

Lignin impedes access to cellulose during biofuel production and pulping but trees can be genetically modified to improve processing efficiency. Modification of lignin may have nontarget effects on mechanical and chemical resistance and subsequent arthropod community responses with respect to pest susceptibility and arthropod biodiversity. We quantified foliar mechanical and chemical resistance traits in lignin-modified and wild-type (WT) poplar (Populus alba × Populus tremula) grown in a plantation and censused arthropods present on these trees to determine total abundance, as well as species richness, diversity and community composition. Our results indicate that mechanical resistance was not affected by lignin modification and only one genetic construct resulted in a (modest) change in chemical resistance. Arthropod abundance and community composition were consistent across modified and WT trees, but transgenics produced using one construct exhibited higher species richness and diversity relative to the WT. Our findings indicate that modification of lignin in poplar does not negatively affect herbivore resistance traits or arthropod community response, and may even result in a source of increased genetic diversity in trees and arthropod communities. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Constitutively elevated salicylic acid levels alter photosynthesis and oxidative state but not growth in transgenic populus.

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Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O; Nyamdari, Batbayar; Wilson, Mark C; Frost, Christopher J; Chen, Han-Yi; Babst, Benjamin A; Harding, Scott A; Tsai, Chung-Jui

2013-07-01

Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained.

Comparative of Quercus spp. and Salix spp. for phytoremediation of Pb/Zn mine tailings.

Science.gov (United States)

Shi, Xiang; Wang, Shufeng; Sun, Haijing; Chen, Yitai; Wang, Dongxue; Pan, Hongwei; Zou, Yazhu; Liu, Jianfeng; Zheng, Linyu; Zhao, Xiulian; Jiang, Zeping

2017-02-01

A pot experiment was conducted to evaluate the feasibility of using tree seedlings for the phytoremediation of lead/zinc (Pb/Zn) mine tailings. Seedlings of three Quercus spp. (Q. shumardii, Q. phellos, and Q. virginiana) and rooted cuttings of two Salix spp. (S. matsudana and S. integra) were transplanted into pots containing 50 and 100 % Pb/Zn mine tailings to evaluate their tolerance of heavy metals. The five species showed different tolerance levels to the Pb/Zn tailings treatments. Q. virginiana was highly tolerant to heavy metals and grew normally in the Pb/Zn tailings. The root systems showed marked differences between the Quercus spp. and Salix spp., indicating that different mechanisms operated to confer tolerance of heavy metals. The maximum efficiency of photosystem II photochemistry value of the five species showed no differences among the treatments, except for Q. shumardii. All species showed low metal translocation factors (TFs). However, S. integra had significantly higher TF values for Zn (1.42-2.18) and cadmium (1.03-1.45) than did the other species. In this respect, Q. virginiana showed the highest tolerance and a low TF, implying that it is a candidate for phytostabilization of mine tailings in southern China. S. integra may be useful for phytoextraction of tailings in temperate regions.

Invasive alien woody plants of the Orange Free State

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L. Henderson

1991-09-01

Full Text Available The frequency and abundance of invasive alien woody plants were recorded along roadsides and at watercourse crossings in 66% (151/230 of the quarter degree squares in the study area. The survey yielded 64 species of which the most prominent (in order of prominence in streambank habitats were:  Salix babylonica, Populus x  canescens, Acacia dealbata and  Salix fragilis (fide R.D. Meikle pers. comm . The most prominent species (in order of prominence in roadside and veld habitats were:  Opunlia ficus-indica, Prunus persica, Eucalyptus spp..  Rosa eglanteria, Pyracantha angustifolia and Acacia dealbata.Little invasion was recorded for most of the province. The greatest intensity of invasion was recorded along the perennial rivers and rocky hillsides in the moist grassland of the eastern mountain region bordering on Lesotho and Natal.

Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

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Wu Fuzhong [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Yang Wanqin, E-mail: scyangwq@163.com [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China); Zhang Jian; Zhou Liqiang [Faculty of Forestry, Sichuan Agricultural University, 625014, Ya' an (China)

2010-05-15

To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 {+-} 19.22 and 576.75 {+-} 40.55 {mu}g cadmium per plant with 110.77 {+-} 12.68 and 202.54 {+-} 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

Water use sources of desert riparian Populus euphratica forests.

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Si, Jianhua; Feng, Qi; Cao, Shengkui; Yu, Tengfei; Zhao, Chunyan

2014-09-01

Desert riparian forests are the main body of natural oases in the lower reaches of inland rivers; its growth and distribution are closely related to water use sources. However, how does the desert riparian forest obtains a stable water source and which water sources it uses to effectively avoid or overcome water stress to survive? This paper describes an analysis of the water sources, using the stable oxygen isotope technique and the linear mixed model of the isotopic values and of desert riparian Populus euphratica forests growing at sites with different groundwater depths and conditions. The results showed that the main water source of Populus euphratica changes from water in a single soil layer or groundwater to deep subsoil water and groundwater as the depth of groundwater increases. This appears to be an adaptive selection to arid and water-deficient conditions and is a primary reason for the long-term survival of P. euphratica in the desert riparian forest of an extremely arid region. Water contributions from the various soil layers and from groundwater differed and the desert riparian P. euphratica forests in different habitats had dissimilar water use strategies.

Uptake of macro- and micro-nutrients into leaf, woody, and root tissue of Populus after irrigation with landfill leachate

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Bart T. Sexton; Richard B. Hall

2008-01-01

Information about macro- and micro-nutrient uptake and distribution into tissues of Populus irrigated with landfill leachate helps to maximize biomass production and understand impacts of leachate chemistry on tree health. We irrigated eight Populus clones (NC 13460, NCI4O18, NC14104, NC14106, DM115, DN5, NM2, NM6) with fertilized (N, P, K) well...

Biomass direct-fired power generation system in China: An integrated energy, GHG emissions, and economic evaluation for Salix

International Nuclear Information System (INIS)

Wang, Changbo; Zhang, Lixiao; Chang, Yuan; Pang, Mingyue

2015-01-01

To gain a better understanding of the options of biomass power generation in China, this study presented an integrated energy, environmental, and economic evaluation for Salix in China, and a typical Salix direct-fired power generation system (SDPGS) in Inner Mongolia was selected for case study. A tiered hybrid life cycle assessment (LCA) model was developed to calculate the “planting-to-wire” (PTW) energy consumption, greenhouse gas (GHG) emissions, and economic cost and profit of the SDPGS, including feedstock cultivation, power plant construction and operation, and on-grid price with/without government subsidies. The results show that the PTW energy consumption and GHG emissions of Salix are 0.8 MJ/kWh and 114 g CO 2 -eq/kWh, respectively, indicating an energy payback time (EPBT) of 3.2 years. The SDPGS is not economically feasible without government subsidies. The PTW costs are dominated by feedstock cultivation. The energy saving and GHG mitigation benefits are still robust, even when the power plant runs at only 60% design capacity. For future development of biomass power in China, scientific planning is necessary to guarantee a sufficient feedstock supply. In addition, technology progress, mature industrial chains, and reasonable price setting policy are required to enable potential energy and environmental advantages of biomass power moving forward. -- Highlights: •A hybrid LCA model was used to evaluate overall performance of the SDPGS. •On-site processes dominate the “planting-to-wire” footprints. •The energy saving and GHG mitigation benefits of the SDPGS are robust. •The economic profit of the SDPGS is feeble without government subsidies. •Generating efficiency promotion has a comprehensive positive effect on the system

Biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli AB1157 cultures submitted to the action of stannous chloride

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RAPHAEL S S SOUZA

2009-01-01

Full Text Available Stannous chloride (SnC12 is used in nuclear medicine as a reducing agent to obtain technetium-99m-radiopharmaceuticals. It have been reported that natural products might reduce the genotoxic and cytotoxic effects related to SnC12. This work evaluated the biological effects of an aqueous extract of Salix alba on the survival of Escherichia coli (E. coli AB1157 (wild type cultures submitted to the action of SnC12. E. coli AB1157 cultures (exponential growth phase were collected by centrifugation, washed and resuspended in 0.9%NaCl. Samples were incubated in water bath shaker with: (a SnC12 (25mg/ml, (bSalix alba extract(11.6mg/ml and (cSnC12(25mg/ml + Salix alba extract (11.6mg/ml. Incubation with 0.9% NaCl was also carried out (control. At 60 min intervals, aliquots were withdrawn, diluted, spread onto Petri dishes with solid LB medium and incubated overnight. The colonies formed were counted and the survival fractions calculated. The extract was not able to protect the E. coli cultures against the lesive action of SnC12. The extract also did not interfere with the survival of the cultures. It suggested that the substances present in the Salix alba aqueous extract did not interfere strongly with cellular metabolism and did not alter the survival fractions of E. coli AB 1157. It is speculated that this extract cannot interfere with the generation of free radicals, the possible main agent responsible for SnC12 lesive action.

Heavy metal accumulation in trees growing on contaminated sites in Central Europe

International Nuclear Information System (INIS)

Unterbrunner, R.; Puschenreiter, M.; Sommer, P.; Wieshammer, G.; Tlustos, P.; Zupan, M.; Wenzel, W.W.

2007-01-01

Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg -1 and 4680 mg Zn kg -1 in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH 4 NO 3 extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg -1 and 116 mg Cd kg -1 in their leaves

Heavy metal accumulation in trees growing on contaminated sites in Central Europe

Energy Technology Data Exchange (ETDEWEB)

Unterbrunner, R. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Puschenreiter, M. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)]. E-mail: markus.puschenreiter@boku.ac.at; Sommer, P. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Wieshammer, G. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria); Tlustos, P. [Czech University of Agriculture Prague, 165 21 Praha 6-Suchdol (Czech Republic); Zupan, M. [University of Ljubljana, Biotechnical Faculty, Agronomy department, Jamnikarjeva 101, 1000 Ljubljana (Slovenia); Wenzel, W.W. [University of Natural Resources and Applied Life Sciences, Vienna - BOKU, Department of Forest and Soil Sciences, Peter Jordan Strasse 82, A-1190 Vienna (Austria)

2007-07-15

Metal-accumulating woody species have been considered for phytoextraction of metal-contaminated sites. We investigated Zn and Cd accumulation in tissues of adult trees and associated herbaceous species collected from contaminated areas in Central Europe. We found considerable Cd and Zn accumulation in various willow, poplar and birch species with up to 116 mg Cd kg{sup -1} and 4680 mg Zn kg{sup -1} in leaves of Salix caprea. Annual variation of Cd and Zn concentrations in leaves of Salix caprea were small, indicating that data obtained in different years can be compared. Metal concentrations in leaves were not related to total (aqua regia) or labile (1 M NH{sub 4}NO{sub 3} extract) concentrations in soil but the accumulation factors (leaf concentration: soil concentration) for Cd and Zn followed an inverse log type function. Metal partitioning between tissues showed a minimum in the wood, with increasing concentrations of Cd and Zn towards the leaves and fine roots. - Adult field-grown Salix caprea, Populus tremula and other tree species accumulate up to 4680 mg Zn kg{sup -1} and 116 mg Cd kg{sup -1} in their leaves.

Genetic basis of aboveground productivity in two native Populus species and their hybrids.

Science.gov (United States)

Lojewski, Nathan R; Fischer, Dylan G; Bailey, Joseph K; Schweitzer, Jennifer A; Whitham, Thomas G; Hart, Stephen C

2009-09-01

Demonstration of genetic control over riparian tree productivity has major implications for responses of riparian systems to shifting environmental conditions and effects of genetics on ecosystems in general. We used field studies and common gardens, applying both molecular and quantitative techniques, to compare plot-level tree aboveground net primary productivity (ANPP(tree)) and individual tree growth rate constants in relation to plant genetic identity in two naturally occurring Populus tree species and their hybrids. In field comparisons of four cross types (Populus fremontii S. Wats., Populus angustifolia James, F(1) hybrids and backcross hybrids) across 11 natural stands, productivity was greatest for P. fremontii trees, followed by hybrids and lowest in P. angustifolia. A similar pattern was observed in four common gardens across a 290 m elevation and 100 km environmental gradient. Despite a doubling in productivity across the common gardens, the relative differences among the cross types remained constant. Using clonal replicates in a common garden, we found ANPP(tree) to be a heritable plant trait (i.e., broad-sense heritability), such that plant genetic factors explained between 38% and 82% of the variation in ANPP(tree). Furthermore, analysis of the genetic composition among individual tree genotypes using restriction fragment length polymorphism molecular markers showed that genetically similar trees also exhibited similar ANPP(tree). These findings indicate strong genetic contributions to natural variation in ANPP with important ecological implications.

Effects of phytoextraction on heavy metal concentrations and pH of pore-water of biosolids determined using an in situ sampling technique.

Science.gov (United States)

Huynh, T T; Laidlaw, W S; Singh, B; Gregory, D; Baker, A J M

2008-12-01

Heavy metal concentrations and pH of pore-water in contaminated substrates are important factors in controlling metal uptake by plants. We investigated the effects of phytoextraction on these properties in the solution phase of biosolids and diluted biosolids in a 12-month phytoextraction column experiment. Phytoextraction using Salix and Populus spp. temporarily decreased pore-water pH of the substrates over the experimental period followed by a return to initial pH conditions. Salixxreichardtii and Populus balsamifera effectively extracted Ni, Zn and Cd and actively mobilized these metals from the solid to the solution phase. S.xreichardtii had the stronger effect on mobilization of metals due to its larger root system. Phytoextraction did not affect Cu in the solution phase of the biosolids. Heavy metals were leached down to lower depths of the columns during the phytoextraction process.

Mapping of quantitative trait loci (QTL) for production, resistance and tolerance traits in Salix. Final Report

Energy Technology Data Exchange (ETDEWEB)

Roennberg-Waestljung, Ann Christin; Bertholdsson, Nils-Ove; Glynn, Carolyn; Weih, Martin; Aahman, Inger [SLU, Uppsala (Sweden). Dept. of Plant Biology and Forest Genetics

2004-05-01

Quantitative trait loci (QTL) for growth traits, water use efficiency and tolerance/resistance against metals and herbivores have been identified. A hybrid F2 population originating from a cross between a Salix dasyclados-clone (SW901290) and a S. viminalis-clone ('Jorunn') was used for the different studies in this project. The growth response was analyzed in a greenhouse experiment with two water treatments, normal and drought. In addition, three field experiments with contrasting soils and climates were established. QTL specific for each treatment or field environment but also QTL stable over the treatments or field environments were detected. Each QTL explained from 8 to 29 % of the phenotypic variation depending on trait, treatment or field environment. Clusters of QTL for different traits were mapped indicating a common genetic base or tightly-linked QTL. Stable QTL identified for dryweight can be useful tools for early selection in Salix. In a separate greenhouse experiment, with a subset of ten genotypes from the F2 population, we show that genotype is more important than irrigation treatment for production of phenolic substances as well as for resistance to herbivory by P vulgatissima.

Transcriptional and Hormonal Regulation of Gravitropism of Woody Stems in Populus

Science.gov (United States)

Suzanne Gerttula; Matthew S. Zinkgraf; Gloria K. Muday; Daniel R. Lewis; Farid M. Ibatullin; Harry Brumer; Foster Hart; Shawn D. Mansfield; Vladimir Filkov; Andrew Groover

2015-01-01

Angiosperm trees reorient their woody stems by asymmetrically producing a specialized xylem tissue, tension wood, which exerts a strong contractile force resulting in negative gravitropism of the stem. Here, we show, in Populus trees, that initial gravity perception and response occurs in specialized cells through sedimentation of starch-filled...

Cadmium accumulation and growth responses of a poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil

International Nuclear Information System (INIS)

Wu Fuzhong; Yang Wanqin; Zhang Jian; Zhou Liqiang

2010-01-01

To characterize the phytoextraction efficiency of a hybrid poplar (Populus deltoids x Populus nigra) in cadmium contaminated purple soil and alluvial soil, a pot experiment in field was carried out in Sichuan basin, western China. After one growing period, the poplar accumulated the highest of 541.98 ± 19.22 and 576.75 ± 40.55 μg cadmium per plant with 110.77 ± 12.68 and 202.54 ± 19.12 g dry mass in these contaminated purple soil and alluvial soil, respectively. Higher phytoextraction efficiency with higher cadmium concentration in tissues was observed in poplar growing in purple soil than that in alluvial soil at relative lower soil cadmium concentration. The poplar growing in alluvial soil had relative higher tolerance ability with lower reduction rates of morphological and growth characters than that in purple soil, suggesting that the poplar growing in alluvial soil might display the higher phytoextraction ability when cadmium contamination level increased. Even so, the poplars exhibited obvious cadmium transport from root to shoot in both soils regardless of cadmium contamination levels. It implies that this examined poplar can extract more cadmium than some hyperaccumulators. The results indicated that metal phytoextraction using the poplar can be applied to clean up soils moderately contaminated by cadmium in these purple soil and alluvial soil.

Gibberellins in shoots and developing capsules of Populus species.

Science.gov (United States)

Pearce, David W; Hutt, Oliver E; Rood, Stewart B; Mander, Lewis N

2002-03-01

Extracts of stems of growing shoots of Populus deltoides and P. trichocarpa, and developing capsules of P. deltoides were analysed for gibberellins (GAs) by gas chromatography-mass spectrometry. The following known GAs were identified by comparison of their Kovats retention indices (KRIs) and mass spectra with those of standards: GA1, GA8, GA9, GA19, GA20, 16 beta,17-dihydro-17-hydroxy GA20, GA23, GA28, GA29, GA34, GA44, and GA97. Several of these have not been previously reported from Populus. In addition, two new GAs were identified as 12 beta-hydroxy GA53 (GA127) and 16 beta,17-dihydro-17-hydroxy GA53 and their structures were confirmed by partial synthesis. Evidence was found of 16,17-dihydro-16,17-dihydroxy GA9, 16,17-dihydro-16,17-dihydroxy GA12, 12-hydroxy GA14, and GA34-catabolite by comparison of mass spectra and KRIs with published data. Several putative GAs (hydroxy- and dihydroxy-GA12-like) were also found. The catabolites of active GAs or of key precursors, hydroxylated at C-2 in stems and either C-2, C-12, C-17, or C-16,17 in capsules, were the major proportion of the GAs.

Pollen viability of Salix myrtilloides L. – an endangered species in Poland

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Magdalena Pogorzelec

2016-12-01

Full Text Available Salix myrtilloides L. (swamp willow is the most endangered species among the boreal Salix species in Poland. The number and size of its population have been decreasing constantly since the 1990s. The main aim of the study was to determine the viability of collected S. myrtilloides pollen and optimal conditions for its in vitro germination. The pollen of S. myrtilloides was collected from 25 male individuals from a population growing in the mid-forest peat bog Dekowina (Sobibór Landscape Park in May 2014. Two methods were applied to estimate the viability of fresh and stored pollen: staining pollen with 2% acetocarmine solution and in vitro germinability. Various temperature (11°C, 23°C and light conditions as well as different concentrations of glucose (1%, 2.5%, 5%, or 7.5% were tested for the optimization of in vitro germination. We documented relatively high S. myrtilloides pollen viability. Pollen tube growth was found to be largely affected by both glucose content in the medium and thermal conditions during germination. Fresh pollen germinated most effectively on the medium with 2.5% glucose (stored pollen – in 5% glucose, at 23°C and in the presence of light. We conclude that pollen viability of S. myrtilloides does not seem to be a limiting factor for reproductive success. Moreover, the pollen is not sterile even after storage for 12 months. The S. myrtilloides individuals from the Dekowina peat bog produce viable pollen grains that are able to germinate and therefore it can be used to pollinate other populations present in the Polesie Lubelskie region for gene pool enrichment.

Spatial Pattern of Populus euphratica Forest Change as Affected by Water Conveyance in the Lower Tarim River

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Shuhong Peng

2014-01-01

Full Text Available To restore declining species, including Populus euphratica and other riparian communities, in the river ecosystem of the lower Tarim River, the ecological water conveyance project (EWCP, as a part of an integrated water resource management plan, was implemented in 2000. The EWCP aims to schedule and manage the water resources in the upper reaches and transfer water to the lower reaches by a series of intermittent water deliveries. The delivered water flows along a modified river channel and nourishes riparian communities by river overflow flooding. Since it began, it has caused a fierce debate over the response of riparian vegetation to the water conveyance scheme. This study focuses on the lower Tarim River, where Populus euphratica forests have undergone watering, due to the EWCP. Twelve Landsat sensor images and one IKONOS satellite imagery acquired between 1999 and 2009 were used to monitor the change in Populus euphratica forests. Bi-temporal change detection and temporal trajectory analysis were employed to represent the spatial pattern of the forest change. Field investigations were used to analyze the driving forces behind forest change from the perspectives of anthropogenic activities and natural forces. The results showed that Populus euphratica forest have been declining in area, which implies that ecological risks have been increased during the watering process. However, forests areas have increased in the regions where the water supply is abundant, and vice versa.

Litter Quality of Populus Species as Affected by Free-Air CO2

NARCIS (Netherlands)

Vermue, E.; Buurman, P.; Hoosbeek, M.R.

2009-01-01

The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter

Light regimes in Populus plantations using the Voxel-based Light Interception Model

NARCIS (Netherlands)

Van der Zande, D.; Dieussart, K.; Stuckens, J.; Verstraeten, W.W.; Coppin, P.

2011-01-01

Three-dimensional light interception by three uniform Populus canopies was studied using the Voxel-based Light Interception Model (VLIM) in combination with ground-based Light Detection and Ranging (LiDAR) measurements. As the VLIM was developed and validated in a virtual environment to ensure

Molecular genetic analysis of black poplar (Populus nigra L.) along Dutch rivers

NARCIS (Netherlands)

Arens, P.; Coops, H.; Jansen, J.; Vosman, B.

1998-01-01

The genetic structure of remaining black poplar (Populus nigra) trees on the banks of the Dutch Rhine branches was investigated using the AFLP technique. In total, 143 trees, including one P. deltoides and some P. x euramericana, were analysed using six AFLP primer combinations which generated 319

Sodium and chloride accumulation in leaf, woody, and root tissue of Populus after irrigation with landfill leachate

International Nuclear Information System (INIS)

Zalesny, Jill A.; Zalesny, Ronald S.; Wiese, Adam H.; Sexton, Bart; Hall, Richard B.

2008-01-01

The response of Populus to irrigation sources containing elevated levels of sodium (Na + ) and chloride (Cl - ) is poorly understood. We irrigated eight Populus clones with fertilized well water (control) (N, P, K) or municipal solid waste landfill leachate weekly during 2005 and 2006 in Rhinelander, Wisconsin, USA (45.6 deg. N, 89.4 deg. W). During August 2006, we tested for differences in total Na + and Cl - concentration in preplanting and harvest soils, and in leaf, woody (stems + branches), and root tissue. The leachate-irrigated soils at harvest had the greatest Na + and Cl - levels. Genotypes exhibited elevated total tree Cl - concentration and increased biomass (clones NC14104, NM2, NM6), elevated Cl - and decreased biomass (NC14018, NC14106, DM115), or mid levels of Cl - and biomass (NC13460, DN5). Leachate tissue concentrations were 17 (Na + ) and four (Cl - ) times greater than water. Sodium and Cl - levels were greatest in roots and leaves, respectively. - Sodium and chloride supplied via landfill leachate irrigation is accumulated at high concentrations in tissues of Populus

Application of two electrical methods for the rapid assessment of freezing resistance in Salix epichloro

Energy Technology Data Exchange (ETDEWEB)

Tsarouhas, V.; Kenney, W.A.; Zsuffa, L. [University of Toronto, Ontario (Canada). Faculty of Forestry

2000-09-01

The importance of early selection of frost-resistant Salix clones makes it desirable to select a rapid and accurate screening method for assessing freezing resistance among several genotypes. Two electrical methods, stem electrical impedance to 1 and 10 khz alternating current, and electrolyte leakage of leaf tissue, were evaluated for detecting freezing resistance on three North America Salix epichloro Michx., clones after subjecting them to five different freezing temperatures (-1, -2, -3, -4, and -5 deg C). Differences in the electrical impedance to 1 and 10 kHz, and the ratio of the impedance at the two frequencies (low/high) before and after the freezing treatment (DZ{sub low}, DZ{sub high}, and DZ{sub ratio}, respectively) were estimated. Electrolyte leakage was expressed as relative conductivity (RC{sub t}) and index of injury (IDX{sub t}). Results from the two methods, obtained two days after the freezing stress, showed that both electrical methods were able to detect freezing injury in S. eriocephala. However, the electrolyte leakage method detected injury in more levels of freezing stress (-3, -4, and -5 deg C) than the impedance (-4, and -5 deg C), it assessed clonal differences in S. eriocephala freezing resistance, and it was best suited to correlate electrical methods with the visual assessed freezing injury. No significant impedance or leakage changes were found after the -1 and -2 deg C freezing temperatures. (author)

A role for stomata in regulating water use efficiency in Populus x ...

African Journals Online (AJOL)

A role for stomata in regulating water use efficiency in Populus x euramericana and characterization of a related gene, PdERECTA. P Guo, X Xia, WL Yin. Abstract. The physiological mechanism of water use efficiency (WUE) remains elucidated, especially in poplar. We studied WUEi (instantaneous leaf transpiration ...

[Seasonal variation of Tamarix ramosissima and Populus euphratica water potentials in southern fringe of Taklamakan Desert].

Science.gov (United States)

Zeng, Fanjiang; Zhang, Ximing; Li, Xiangyi; Foetzki, Andrea; Runge, Michael

2005-08-01

The measurement of the seasonal and diurnal variations of Tamarix ramosissima and Populus euphratica water potentials in the southern fringe of Taklamakan Desert indicated that there was no apparent water stress for the two species during their growth period, with little change of predawn water potential and some extent decrease of midday water potential. Irrigation once or thinning had no significant effects on the water status of the plants, while groundwater appeared to be a prerequisite for the survival and growth of these species. It is very important to ensure a stable groundwater table for the restoration of Tamarix ramosissima and Populus euphratica in this area.

The Effect of Trichoderma on Heavy Metal Mobility and Uptake by Miscanthus giganteus, Salix sp., Phalaris arundinacea, and Panicum virgatum

Directory of Open Access Journals (Sweden)

Malgorzata J. Kacprzak

2014-01-01

Full Text Available The effect of land application of biomaterials based on two strains of Trichoderma fungus on phytoremediation processes was studied. Six metals (Cd, Cr, Cu, Pb, Zn, and Ni were analysed in soil and soil leachate as well as in plant tissues. The translocation index (Ti and metal bioconcentration factors (BCF calculated for the inoculated plants were increased compared to the noninoculated control, except for Pb and Salix sp. Simultaneously, the mobilisation of metals in soil solution as an effect of biomaterials was noted. The highest values of Ti—339% (for Cr, 190% (for Ni, and 110% (for Cu—were achieved for the combination Miscanteus giganteus and Trichoderma MSO1. The results indicated that the application of fungus has positive effects on increasing the biomass, soil parameters (C, N, and P, and solubility of heavy metals in soil and therefore in enhancing phytoextraction for Miscanthus giganteus L., Panicum virgatum L., Phalaris arundinacea L., and Salix sp.

Elevated atmospheric CO2 concentration leads to increased whole-plant isoprene emission in hybrid aspen (Populus tremula × Populus tremuloides).

Science.gov (United States)

Sun, Zhihong; Niinemets, Ülo; Hüve, Katja; Rasulov, Bahtijor; Noe, Steffen M

2013-05-01

Effects of elevated atmospheric [CO2] on plant isoprene emissions are controversial. Relying on leaf-scale measurements, most models simulating isoprene emissions in future higher [CO2] atmospheres suggest reduced emission fluxes. However, combined effects of elevated [CO2] on leaf area growth, net assimilation and isoprene emission rates have rarely been studied on the canopy scale, but stimulation of leaf area growth may largely compensate for possible [CO2] inhibition reported at the leaf scale. This study tests the hypothesis that stimulated leaf area growth leads to increased canopy isoprene emission rates. We studied the dynamics of canopy growth, and net assimilation and isoprene emission rates in hybrid aspen (Populus tremula × Populus tremuloides) grown under 380 and 780 μmol mol(-1) [CO2]. A theoretical framework based on the Chapman-Richards function to model canopy growth and numerically compare the growth dynamics among ambient and elevated atmospheric [CO2]-grown plants was developed. Plants grown under elevated [CO2] had higher C : N ratio, and greater total leaf area, and canopy net assimilation and isoprene emission rates. During ontogeny, these key canopy characteristics developed faster and stabilized earlier under elevated [CO2]. However, on a leaf area basis, foliage physiological traits remained in a transient state over the whole experiment. These results demonstrate that canopy-scale dynamics importantly complements the leaf-scale processes, and that isoprene emissions may actually increase under higher [CO2] as a result of enhanced leaf area production. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Seasonal dynamics and effects of nitrogen supply rate on nitrogen and carbohydrate reserves in cutting-derived Salix viminalis plants

Science.gov (United States)

Lars Bollmark; Lisa Sennerby-Forsse; Tom Ericsson

1999-01-01

Nurient storage is an important aspect of resprouting potential and production of Salix viminalis L., a pioneer species used for biomas production in weden. Seasonal dynamics of nitrogen (N), protien, soluble arbohydrates, starches, and lipids were studied in roots, cutting, stems, and leaves during a full growth cycle induced by varying photoperiod...

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2011-01-01

, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

SPTEdb: a database for transposable elements in salicaceous plants

Science.gov (United States)

Jia, Zirui; Xiao, Yao; Ma, Wenjun; Wang, Junhui

2018-01-01

Abstract Although transposable elements (TEs) play significant roles in structural, functional and evolutionary dynamics of the salicaceous plants genome and the accurate identification, definition and classification of TEs are still inadequate. In this study, we identified 18 393 TEs from Populus trichocarpa, Populus euphratica and Salix suchowensis using a combination of signature-based, similarity-based and De novo method, and annotated them into 1621 families. A comprehensive and user-friendly web-based database, SPTEdb, was constructed and served for researchers. SPTEdb enables users to browse, retrieve and download the TEs sequences from the database. Meanwhile, several analysis tools, including BLAST, HMMER, GetORF and Cut sequence, were also integrated into SPTEdb to help users to mine the TEs data easily and effectively. In summary, SPTEdb will facilitate the study of TEs biology and functional genomics in salicaceous plants. Database URL: http://genedenovoweb.ticp.net:81/SPTEdb/index.php PMID:29688371

Constitutively Elevated Salicylic Acid Levels Alter Photosynthesis and Oxidative State but Not Growth in Transgenic Populus[C][W

Science.gov (United States)

Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O.; Nyamdari, Batbayar; Wilson, Mark C.; Frost, Christopher J.; Chen, Han-Yi; Babst, Benjamin A.; Harding, Scott A.; Tsai, Chung-Jui

2013-01-01

Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained. PMID:23903318

Exotic woody plant invaders of the Transvaal

Directory of Open Access Journals (Sweden)

L. Henderson

1984-12-01

Full Text Available The frequency and abundance o ;f exotic, woody plant invaders were recorded in 60% of the quarter degree squares in the study area. Sixty-one invaders were encountered o f which the most important and aggressive were Acacia dealbaia, Populus spp.,  Melia azedarach, Opuntia ficus-indica, Salix babylonica and  Acacia mearnsii. Invasion patterns are discussed and an attempt is made to correlate distribution with environmental factors. Attention is drawn to the areas of greatest invasion and the areas that are liable to show the greatest expansion in the future.

Comparative physiology of allopatric Populus species: geographic clines in photosynthesis, height growth, and carbon isotope discrimination in common gardens.

Science.gov (United States)

Soolanayakanahally, Raju Y; Guy, Robert D; Street, Nathaniel R; Robinson, Kathryn M; Silim, Salim N; Albrectsen, Benedicte R; Jansson, Stefan

2015-01-01

Populus species with wide geographic ranges display strong adaptation to local environments. We studied the clinal patterns in phenology and ecophysiology in allopatric Populus species adapted to similar environments on different continents under common garden settings. As a result of climatic adaptation, both Populus tremula L. and Populus balsamifera L. display latitudinal clines in photosynthetic rates (A), whereby high-latitude trees of P. tremula had higher A compared to low-latitude trees and nearly so in P. balsamifera (p = 0.06). Stomatal conductance (g s) and chlorophyll content index (CCI) follow similar latitudinal trends. However, foliar nitrogen was positively correlated with latitude in P. balsamifera and negatively correlated in P. tremula. No significant trends in carbon isotope composition of the leaf tissue (δ(13)C) were observed for both species; but, intrinsic water-use efficiency (WUEi) was negatively correlated with the latitude of origin in P. balsamifera. In spite of intrinsically higher A, high-latitude trees in both common gardens accomplished less height gain as a result of early bud set. Thus, shoot biomass was determined by height elongation duration (HED), which was well approximated by the number of days available for free growth between bud flush and bud set. We highlight the shortcoming of unreplicated outdoor common gardens for tree improvement and the crucial role of photoperiod in limiting height growth, further complicating interpretation of other secondary effects.

Increasing the productivity of biomass plantations of Populus species and hybrids in the Pacific Northwest. Final report, September 14, 1981--December 31, 1996

Energy Technology Data Exchange (ETDEWEB)

DeBell, D.S.; Harrington, C.A.; Clendenen, G.W. [USDA Forest Service, Olympia, WA (United States)] [and others

1997-08-01

This final report represents the culmination of eight years of biological research devoted to increasing the productivity of short rotation plantations of Populus trichocarpa and Populus hybrids in the Pacific Northwest. Studies described herein provide an understanding of tree growth, stand development and biomass yield at various spacings, and how patterns thereof differ by Populus clone in monoclonal and polyclonal plantings. Also included is some information about factors related to wind damage in Populus plantings, use of leaf size as a predictor of growth potential, and approaches for estimating tree and stand biomass and biomass growth. The work was accomplished in three research plantations, all established cooperatively with the Washington State Department of Natural Resources (DNR) and located at the DNR Tree Improvement Center near Olympia. The first plantation was established in Spring 1986 to evaluate the highly touted {open_quotes}woodgrass{close_quotes} concept and compare it with more conventional short-rotation management regimes, using two Populus hybrid clones planted at five spacings. Besides providing scientific data to resolve the politicized {open_quotes}wood-grass{close_quotes} dispute, this plantation has furnished excellent data on stand dynamics and woody biomass yield. A second plantation was established at the same time; groups of trees therein received two levels of irrigation and different amounts of four fertilizer amendments, resulting in microsites with diverse moisture and nutrient conditions.

Twenty-one genome sequences from Pseudomonas species and 19 genome sequences from diverse bacteria isolated from the rhizosphere and endosphere of Populus deltoides.

Science.gov (United States)

Brown, Steven D; Utturkar, Sagar M; Klingeman, Dawn M; Johnson, Courtney M; Martin, Stanton L; Land, Miriam L; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A

2012-11-01

To aid in the investigation of the Populus deltoides microbiome, we generated draft genome sequences for 21 Pseudomonas strains and 19 other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium, and Variovorax were generated.

Using low energy x-ray radiography to evaluate root initiation and growth of Populus

Science.gov (United States)

Ronald S., Jr. Zalesny; A. L. Friend; B. Kodrzycki; D.W. McDonald; R. Michaels; A.H. Wiese; J.W. Powers

2007-01-01

Populus roots have been studied less than aboveground tissues. However, there is an overwhelming need to evaluate root initiation and growth in order to understand the genetics and physiology of rooting, along with genotype x environment interactions.

Twenty-One Genome Sequences from Pseudomonas Species and 19 Genome Sequences from Diverse Bacteria Isolated from the Rhizosphere and Endosphere of Populus deltoides

Energy Technology Data Exchange (ETDEWEB)

Brown, Steven D [ORNL; Utturkar, Sagar M [ORNL; Klingeman, Dawn Marie [ORNL; Johnson, Courtney M [ORNL; Martin, Stanton [ORNL; Land, Miriam L [ORNL; Lu, Tse-Yuan [ORNL; Schadt, Christopher Warren [ORNL; Doktycz, Mitchel John [ORNL; Pelletier, Dale A [ORNL

2012-01-01

To aid in the investigation of the Populus deltoides microbiome we generated draft genome sequences for twenty one Pseudomonas and twenty one other diverse bacteria isolated from Populus deltoides roots. Genome sequences for isolates similar to Acidovorax, Bradyrhizobium, Brevibacillus, Burkholderia, Caulobacter, Chryseobacterium, Flavobacterium, Herbaspirillum, Novosphingobium, Pantoea, Phyllobacterium, Polaromonas, Rhizobium, Sphingobium and Variovorax were generated.

Shifting dominance of riparian Populus and Tamarix along gradients of flow alteration in western North American rivers.

Science.gov (United States)

Merritt, David M; Poff, N LeRoy

2010-01-01

Tamarix ramosissima is a naturalized, nonnative plant species which has become widespread along riparian corridors throughout the western United States. We test the hypothesis that the distribution and success of Tamarix result from human modification of river-flow regimes. We conducted a natural experiment in eight ecoregions in arid and semiarid portions of the western United States, measuring Tamarix and native Populus recruitment and abundance at 64 sites along 13 perennial rivers spanning a range of altered flow regimes. We quantified biologically relevant attributes of flow alteration as an integrated measure (the index of flow modification, IFM), which was then used to explain between-site variation in abundance and recruitment of native and nonnative riparian plant species. We found the likelihood of successful recruitment of Tamarix to be highest along unregulated river reaches and to remain high across a gradient of regulated flows. Recruitment probability for Populus, in contrast, was highest under free-flowing conditions and declined abruptly under even slight flow modification (IFM > 0.1). Adult Tamarix was most abundant at intermediate levels of IFM. Populus abundance declined sharply with modest flow regulation (IFM > 0.2) and was not present at the most flow-regulated sites. Dominance of Tamarix was highest along rivers with the most altered flow regimes. At the 16 least regulated sites, Tamarix and Populus were equally abundant. Given observed patterns of Tamarix recruitment and abundance, we infer that Tamarix would likely have naturalized, spread, and established widely in riparian communities in the absence of dam construction, diversions, and flow regulation in western North America. However, Tamarix dominance over native species would likely be less extensive in the absence of human alteration of river-flow regimes. Restoration that combines active mechanical removal of established stands of Tamarix with a program of flow releases conducive to

Soil hydrology of agroforestry systems: Competition for water or positive tree-crops interactions?

Science.gov (United States)

Gerjets, Rowena; Richter, Falk; Jansen, Martin; Carminati, Andrea

2017-04-01

In dry periods during the growing season crops may suffer from severe water stress. The question arises whether the alternation of crop and tree strips might enhance and sustain soil water resources available for crops during drought events. Trees reduce wind exposure, decreasing the potential evapotranspiration of crops and soils; additionally hydraulic lift from the deep roots of trees to the drier top soil might provide additional water for shallow-rooted crops. To understand the above and belowground water relations of agroforestry systems, we measured soil moisture and soil water potential in crop strips as a function of distance to the trees at varying depth as well as meteorological parameters. At the agroforestry site Reiffenhausen, Lower Saxony, Germany, two different tree species are planted, each in one separated tree strip: willow breed Tordis ((Salix viminalis x Salix Schwerinii) x Salix viminalis) and poplar clone Max 1 (Populus nigra x Populus maximowiczii). In between the tree strips a crop strip of 24 m width was established with annual crop rotation, managed the same way as the reference site. During a drought period in May 2016 with less than 2 mm rain in four weeks, an overall positive effect on hydrological conditions of the agroforestry system was observed. The results show that trees shaded the soil surface, lowering the air temperature and further increasing the soil moisture in the crop strips compared to the reference site, which was located far from the trees. At the reference site the crops took up water in the upper soil (sunlight. The two tree species behaved differently. The poplar strips showed more marked diurnal changes in soil water potential, with fast drying during daytime and rewetting during nighttime. We suppose that the rewetting during nighttime was caused by hydraulic lift, which supports passively the drier upper soil with water from the wetter, lower soil layers. This experimental study shows the importance of above- and

Bud removal affects shoot, root, and callus development of hardwood Populus cuttings

Science.gov (United States)

A.H. Wiese; J.A. Zalesny; D.M. Donner; Ronald S., Jr. Zalesny

2006-01-01

The inadvertent removal and/or damage of buds during processing and planting of hardwood poplar (Populus spp.) cuttings are a concern because of their potential impact on shoot and root development during establishment. The objective of the current study was to test for differences in shoot dry mass, root dry mass, number of roots, length of the...

Shoot position affects root initiation and growth of dormant unrooted cuttings of Populus

Science.gov (United States)

R.S., Jr. Zalesny; R.B. Hall; E.O. Bauer; D.E. Riemenschneider

2003-01-01

Rooting of dormant unrooted cuttings is crucial to the commercial deployment of intensively cultured poplar (Populus spp.) plantations because it is the first biological prerequisite to stand establishment. Rooting can be genetically controlled and subject to selection. Thus, our objective was to test for differences in rooting ability among cuttings...

Clonal variation in lateral and basal rooting of Populus irrigated with landfill leachate

Science.gov (United States)

R.S. Zalesny Jr.; J.A. Zalesny

2011-01-01

Successful establishment and productivity of Populus depends upon adventitious rooting from: 1) lateral roots that develop from either preformed or induced primordia and 2) basal roots that differentiate from callus at the base of the cutting in response to wounding. Information is needed for phytotechnologies about the degree to which ...

RNA sequencing of Populus x canadensis roots identifies key molecular mechanisms underlying physiological adaption to excess zinc.

Directory of Open Access Journals (Sweden)

Andrea Ariani

Full Text Available Populus x canadensis clone I-214 exhibits a general indicator phenotype in response to excess Zn, and a higher metal uptake in roots than in shoots with a reduced translocation to aerial parts under hydroponic conditions. This physiological adaptation seems mainly regulated by roots, although the molecular mechanisms that underlie these processes are still poorly understood. Here, differential expression analysis using RNA-sequencing technology was used to identify the molecular mechanisms involved in the response to excess Zn in root. In order to maximize specificity of detection of differentially expressed (DE genes, we consider the intersection of genes identified by three distinct statistical approaches (61 up- and 19 down-regulated and validate them by RT-qPCR, yielding an agreement of 93% between the two experimental techniques. Gene Ontology (GO terms related to oxidation-reduction processes, transport and cellular iron ion homeostasis were enriched among DE genes, highlighting the importance of metal homeostasis in adaptation to excess Zn by P. x canadensis clone I-214. We identified the up-regulation of two Populus metal transporters (ZIP2 and NRAMP1 probably involved in metal uptake, and the down-regulation of a NAS4 gene involved in metal translocation. We identified also four Fe-homeostasis transcription factors (two bHLH38 genes, FIT and BTS that were differentially expressed, probably for reducing Zn-induced Fe-deficiency. In particular, we suggest that the down-regulation of FIT transcription factor could be a mechanism to cope with Zn-induced Fe-deficiency in Populus. These results provide insight into the molecular mechanisms involved in adaption to excess Zn in Populus spp., but could also constitute a starting point for the identification and characterization of molecular markers or biotechnological targets for possible improvement of phytoremediation performances of poplar trees.

Phytoextraction of initial cutting of Salix matsudana for Cd and Cu.

Science.gov (United States)

Wang, Wen-Wen; Cheng, Liu Ke; Hao, Jie Wei; Guan, Xin; Tian, Xing-Jun

2016-06-27

Salix species are widely used as vegetation filters because of their flourishing root system and fast growth rate. However, studies have yet to determine whether the root system functions in vegetable filters with mixed heavy metal (HM) pollution or whether initial cutting participates in the phytoextraction of HMs. This study aims to determine the function of the root system and initial cutting as vegetation filters in the absorption and accumulation of Cd and Cu. Thick (>1 cm in diameter) and fine (phytoextraction capacity of plants. The initial cuttings could also absorb and accumulate HMs in the early growth stages of willow without roots. Cu inhibited the plant absorption and accumulation of Cd and promoted Cd transport to shoots. Cd inhibited the Cu absorption of the root system. Our study provided essential data regarding woody species as vegetation filters of HM pollution.

Isolation and characterization of cDNAs encoding leucoanthocyanidin reductase and anthocyanidin reductase from Populus trichocarpa.

Directory of Open Access Journals (Sweden)

Lijun Wang

Full Text Available Proanthocyanidins (PAs contribute to poplar defense mechanisms against biotic and abiotic stresses. Transcripts of PA biosynthetic genes accumulated rapidly in response to infection by the fungus Marssonina brunnea f.sp. multigermtubi, treatments of salicylic acid (SA and wounding, resulting in PA accumulation in poplar leaves. Anthocyanidin reductase (ANR and leucoanthocyanidin reductase (LAR are two key enzymes of the PA biosynthesis that produce the main subunits: (+-catechin and (--epicatechin required for formation of PA polymers. In Populus, ANR and LAR are encoded by at least two and three highly related genes, respectively. In this study, we isolated and functionally characterized genes PtrANR1 and PtrLAR1 from P. trichocarpa. Phylogenetic analysis shows that Populus ANR1 and LAR1 occurr in two distinct phylogenetic lineages, but both genes have little difference in their tissue distribution, preferentially expressed in roots. Overexpression of PtrANR1 in poplar resulted in a significant increase in PA levels but no impact on catechin levels. Antisense down-regulation of PtrANR1 showed reduced PA accumulation in transgenic lines, but increased levels of anthocyanin content. Ectopic expression of PtrLAR1 in poplar positively regulated the biosynthesis of PAs, whereas the accumulation of anthocyanin and flavonol was significantly reduced (P<0.05 in all transgenic plants compared to the control plants. These results suggest that both PtrANR1 and PtrLAR1 contribute to PA biosynthesis in Populus.

Mycorrhizal associations as Salix repens L. communities in succession of dune ecosystems II Mycorrhizal dynamics and interactions of ectomycorrhizal and arbuscular mycorrhizal fungi

NARCIS (Netherlands)

Heijden, van der E.W.; Vosatka, M.

2000-01-01

Ectomycorrhizal (EcM) and arbuscular mycorrhizal (AM) associations of Salix repens were studied at 16 sites in different successional stages of dune ecosystems (calcareous-acidic, dry-wet) in the Netherlands. High EcM colonization, low AM colonization, and lack of differences between habitats

Remetabolism of transpired ethanol by Populus deltoides

International Nuclear Information System (INIS)

MacDonald, R.C.; Kimmerer, T.W.

1990-01-01

Ethanol is present in the transpiration stream of flooded and unflooded trees in concentrations up to 0.5mM. Transpired ethanol does not evaporate but is remetabolized by foliage and upper stems in Populus deltoides. 14 C-ethanol was supplied in the transpiration stream to excised leaves and shoots; more than 98% was incorporated. Less than 1% was respired as CO 2 . Organic and amino acids were labelled initially, with eventual accumulations in water- and chloroform-soluble fractions and into protein. Much of the label was incorporated into stem tissue, with little reaching the lamina. These experiments suggest that ethanol is not lost transpirationally through the leaves, but is efficiently recycled in a manner resembling lactate recycling in mammals

Leaf chemical composition of twenty-one Populus hybrid clones grown under intensive culture

Science.gov (United States)

Richard E. Dickson; Philip R. Larson

1976-01-01

Leaf material from 21 nursery-grown Populus hybrid clones was analyzed for three nitrogen fractions (total N, soluble protein, and soluble amino acids) and three carbhydrate fractions (reducing sugars, total soluble sugars, and total nonstructural carbohydrates-TNC). In addition, nursery-grown green ash and silver maple, field-grown bigtooth and trembling aspen, and...

Thidiazuron: A potent cytokinin for efficient plant regeneration in Himalayan poplar (Populus ciliata Wall. using leaf explants

Directory of Open Access Journals (Sweden)

Gaurav Aggarwal

2012-11-01

Full Text Available Populus species are important resource for certain branches of industry and have special roles for scientific study on biological and agricultural systems. The present investigation was undertaken with an objective of enhancing the frequency of plant regeneration in Himalayan poplar (Populus ciliata Wall.. The effect of Thiadizuron (TDZ alone and in combination with adenine and α-Naphthalene acetic acid (NAA were studied on the regeneration potential of leaf explants. A high efficiency of shoot regeneration was observed in leaf (80.00% explants on MS basal medium supplemented with 0.024 mg/l TDZ and 79.7 mg/l adenine. Elongation and multiplication of shoots were obtained on Murashige and Skoog (MS basal medium, containing 0.5 mg/l 6. Benzyl aminopurine (BAP + 0.2mg/l Indole 3-acetic acid (IAA + 0.3 mg/l Gibberellic acid (GA3. High frequency root regeneration from in vitro developed shoots was observed on MS basal medium supplemented with 0.10 mg/l Indole 3-butyric acid(IBA. Maximum of the in vitro rooted plantlets were well accomplished to the mixture of sand: soil (1:1 and exhibited similar morphology with the field plants. A high efficiency plant regeneration protocol has been developedfrom leaf explants in Himalayan poplar (Populus ciliata Wall..

Comparative interrogation of the developing xylem transcriptomes of two wood-forming species: Populus trichocarpa and Eucalyptus grandis.

Science.gov (United States)

Hefer, Charles A; Mizrachi, Eshchar; Myburg, Alexander A; Douglas, Carl J; Mansfield, Shawn D

2015-06-01

Wood formation is a complex developmental process governed by genetic and environmental stimuli. Populus and Eucalyptus are fast-growing, high-yielding tree genera that represent ecologically and economically important species suitable for generating significant lignocellulosic biomass. Comparative analysis of the developing xylem and leaf transcriptomes of Populus trichocarpa and Eucalyptus grandis together with phylogenetic analyses identified clusters of homologous genes preferentially expressed during xylem formation in both species. A conserved set of 336 single gene pairs showed highly similar xylem preferential expression patterns, as well as evidence of high functional constraint. Individual members of multi-gene orthologous clusters known to be involved in secondary cell wall biosynthesis also showed conserved xylem expression profiles. However, species-specific expression as well as opposite (xylem versus leaf) expression patterns observed for a subset of genes suggest subtle differences in the transcriptional regulation important for xylem development in each species. Using sequence similarity and gene expression status, we identified functional homologs likely to be involved in xylem developmental and biosynthetic processes in Populus and Eucalyptus. Our study suggests that, while genes involved in secondary cell wall biosynthesis show high levels of gene expression conservation, differential regulation of some xylem development genes may give rise to unique xylem properties. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Xylan hydrolysis in Populus trichocarpa × P. deltoides and model substrates during hydrothermal pretreatment.

Science.gov (United States)

Trajano, Heather L; Pattathil, Sivakumar; Tomkins, Bruce A; Tschaplinski, Timothy J; Hahn, Michael G; Van Berkel, Gary J; Wyman, Charles E

2015-03-01

Previous studies defined easy and difficult to hydrolyze fractions of hemicellulose that may result from bonds among cellulose, hemicellulose, and lignin. To understand how such bonds affect hydrolysis, Populus trichocarpa × Populus deltoides, holocellulose isolated from P. trichocarpa × P. deltoides and birchwood xylan were subjected to hydrothermal flow-through pretreatment. Samples were characterized by glycome profiling, HPLC, and UPLC-MS. Glycome profiling revealed steady fragmentation and removal of glycans from solids during hydrolysis. The extent of polysaccharide fragmentation, hydrolysis rate, and total xylose yield were lowest for P. trichocarpa × P. deltoides and greatest for birchwood xylan. Comparison of results from P. trichocarpa × P. deltoides and holocellulose suggested that lignin-carbohydrate complexes reduce hydrolysis rates and limit release of large xylooligomers. Smaller differences between results with holocellulose and birchwood xylan suggest xylan-cellulose hydrogen bonds limited hydrolysis, but to a lesser extent. These findings imply cell wall structure strongly influences hydrolysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

A genomics investigation of partitioning into and among flavonoid-derived condensed tannins for carbon sequestration in Populus

Energy Technology Data Exchange (ETDEWEB)

Harding, Scott, A; Tsai, Chung-jui; Lindroth, Richard, L

2013-03-24

The project set out to use comparative (genotype and treatment) and transgenic approaches to investigate the determinants of condensed tannin (CT) accrual and chemical variability in Populus. CT type and amount are thought to effect the decomposition of plant detritus in the soil, and thereby the sequestering of carbon in the soil. The stated objectives were: 1. Genome-wide transcriptome profiling (microarrays) to analyze structural gene, transcription factor and metabolite control of CT partitioning; 2. Transcriptomic (microarray) and chemical analysis of ontogenetic effects on CT and PG partitioning; and 3. Transgenic manipulation of flavonoid biosynthetic pathway genes to modify the control of CT composition. Objective 1: A number of approaches for perturbing CT content and chemistry were tested in Objective 1, and those included nitrogen deficit, leaf wounding, drought, and salicylic acid spraying. Drought had little effect on CTs in the genotypes we used. Plants exhibited unpredictability in their response to salicylic acid spraying, leading us to abandon its use. Reduced plant nitrogen status and leaf wounding caused reproducible and magnitudinally striking increases in leaf CT content. Microarray submissions to NCBI from those experiments are the following: GSE ID 14515: Comparative transcriptomics analysis of Populus leaves under nitrogen limitation: clone 1979. Public on Jan 04, 2010; Contributor(s) Harding SA, Tsai C GSE ID 14893: Comparative transcriptomics analysis of Populus leaves under nitrogen limitation: clone 3200. Public on Feb 19, 2009; Contributor(s) Harding SA, Tsai C GSE ID 16783 Wound-induced gene expression changes in Populus: 1 week; clone RM5. Status Public on Dec 01, 2009; Contributor(s) Harding SA, Tsai C GSE ID 16785 Wound-induced gene expression changes in Populus: 90 hours; clone RM5 Status Public on Dec 01, 2009; Contributor(s) Harding SA, Tsai C Although CT amount changed in response to treatments, CT composition was essentially

Influence of Populus Genotype on Gene Expression by the Wood Decay Fungus Phanerochaete chrysosporium

Science.gov (United States)

Jill Gaskell; Amber Marty; Michael Mozuch; Philip J. Kersten; Sandra Splinter Bondurant; Grzegorz Sabat; Ali Azarpira; John Ralph; Oleksandr Skyba; Shawn D. Mansfield; Robert A. Blanchette; Dan Cullen

2014-01-01

We examined gene expression patterns in the lignin-degrading fungus Phanerochaete chrysosporium when it colonizes hybrid poplar (Populus alba tremula) and syringyl (S)-rich transgenic derivatives. Acombination ofmicroarrays and liquid chromatography- tandem mass spectrometry (LC-MS/MS) allowed detection of a total of 9,959 transcripts and 793...

Diversity of Pseudomonas Genomes, Including Populus-Associated Isolates, as Revealed by Comparative Genome Analysis.

Science.gov (United States)

Jun, Se-Ran; Wassenaar, Trudy M; Nookaew, Intawat; Hauser, Loren; Wanchai, Visanu; Land, Miriam; Timm, Collin M; Lu, Tse-Yuan S; Schadt, Christopher W; Doktycz, Mitchel J; Pelletier, Dale A; Ussery, David W

2016-01-01

The Pseudomonas genus contains a metabolically versatile group of organisms that are known to occupy numerous ecological niches, including the rhizosphere and endosphere of many plants. Their diversity influences the phylogenetic diversity and heterogeneity of these communities. On the basis of average amino acid identity, comparative genome analysis of >1,000 Pseudomonas genomes, including 21 Pseudomonas strains isolated from the roots of native Populus deltoides (eastern cottonwood) trees resulted in consistent and robust genomic clusters with phylogenetic homogeneity. All Pseudomonas aeruginosa genomes clustered together, and these were clearly distinct from other Pseudomonas species groups on the basis of pangenome and core genome analyses. In contrast, the genomes of Pseudomonas fluorescens were organized into 20 distinct genomic clusters, representing enormous diversity and heterogeneity. Most of our 21 Populus-associated isolates formed three distinct subgroups within the major P. fluorescens group, supported by pathway profile analysis, while two isolates were more closely related to Pseudomonas chlororaphis and Pseudomonas putida. Genes specific to Populus-associated subgroups were identified. Genes specific to subgroup 1 include several sensory systems that act in two-component signal transduction, a TonB-dependent receptor, and a phosphorelay sensor. Genes specific to subgroup 2 contain hypothetical genes, and genes specific to subgroup 3 were annotated with hydrolase activity. This study justifies the need to sequence multiple isolates, especially from P. fluorescens, which displays the most genetic variation, in order to study functional capabilities from a pangenomic perspective. This information will prove useful when choosing Pseudomonas strains for use to promote growth and increase disease resistance in plants. Copyright © 2015 Jun et al.

Soil temperature and precipitation affect the rooting ability of dormant hardwood cuttings of Populus

Science.gov (United States)

R.S., Jr. Zalesny; R.B. Hall; E.O. Bauer; D.E. Riemenschneider

2005-01-01

In addition to genetic control, responses to environmental stimuli affect the success of rooting. Our objectives were to: 1) assess the variation in rooting ability among 21 Populus clones grown under varying soil temperatures and amounts of precipitation and 2) identify combinations of soil temperature and precipitation that promote rooting. The...

Influence of Ca/Mg ratio on phytoextraction properties of Salix viminalis. II. Secretion of low molecular weight organic acids to the rhizosphere.

Science.gov (United States)

Magdziak, Z; Kozlowska, M; Kaczmarek, Z; Mleczek, M; Chadzinikolau, T; Drzewiecka, K; Golinski, P

2011-01-01

A hydroponic experiment in a phytotron was performed to investigate the effect of two different Ca/Mg ratios (4:1 and 1:10) and trace element ions (Cd, Cu, Pb and Zn) in solution on the efficiency of low molecular weight organic acid (LMWOA) formation in Salix viminalis rhizosphere. Depending on the Ca/Mg ratio and presence of selected trace elements at 0.5mM concentration, the amount and kind of LMWOAs in the rhizosphere were significantly affected. In physiological 4:1 Ca/Mg ratio the following complex of acids was observed: malonic (Pb, Zn), citric, lactic, maleic and succinic (Zn) acids. Under 1:10 Ca/Mg ratio, citric (Cd, Zn), maleic and succinic (Cd, Cu, Pb, Zn) acids were seen. Additionally, high accumulation of zinc and copper in all systems was observed, with the exception of those where one of the metals was at higher concentration. Summing up, the results indicate a significant role of LMWOAs in Salix phytoremediation abilities. Both effects can be modulated depending on the mutual Ca/Mg ratio. Copyright © 2010 Elsevier Inc. All rights reserved.

The effect of pH on the uptake and toxicity of the bivalent weak base chloroquine tested on Salix viminalis and Daphnia magna

DEFF Research Database (Denmark)

Rendal, Cecilie; Kusk, Kresten Ole; Trapp, Stefan

2011-01-01

, and therefore a higher toxicity can be expected. The current study examines the pHdependent toxicity and bioaccumulation of the bivalent weak base chloroquine (pKa: 10.47 and 6.33, log KOW 4.67) tested on Salix viminalis (basket willow) and Daphnia magna (water flea). The transpiration rates of hydroponically...

Chloride and sodium uptake potential over an entire rotation of Populus irrigated with landfill leachate

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny

2009-01-01

There is a need for information about the response of Populus genotypes to repeated application of high-salinity water and nutrient sources throughout an entire rotation. We have combined establishment biomass and uptake data with mid- and full-rotation growth data to project potential chloride (Cl−) and sodium (Na...

Fungal community structure under goat willows (Salix caprea L.) growing at metal polluted site: the potential of screening in a model phytostabilisation study

Science.gov (United States)

Marjana Regvar; Matevz Likar; Andrej Piltaver; Nives Kugonic; Jane E. Smith

2010-01-01

Goat willow (Salix caprea L.) was selected in a previous vegetation screening study as a potential candidate for the later-stage phytostabilisation efforts at a heavily metal polluted site in Slovenia. The aims of this study were to identify the fungi colonising roots of S. caprea along the gradient of vegetation succession and...

Biomonitoring polycyclic aromatic hydrocarbons by Salix matsudana leaves: A comparison with the relevant air content and evaluation of environmental parameter effects

Science.gov (United States)

Zhao, Xiangai; He, Miao; Shang, Haibo; Yu, Hongling; Wang, Hao; Li, Huijie; Piao, Jingyi; Quinto, Maurizio; Li, Donghao

2018-05-01

Studies on seasonal distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in Salix matsudana leaves covering its annual life cycle were carried out in order to evaluate plant leaf response sensitivity to air pollution. Salix matsudana leaves were collected throughout different development phases of plant leaf inclusive of bud break to fallen leaves, covering from spring (May) to autumn (November). Simultaneously, particle and gas samples were collected using a high volume air sampler. Seven different PAHs were determined simultaneously in these samples. The temperature dependence of the partitioning of PAHs in air and plant leaves was investigated and the results were incorporated into a mathematical model. The measured plant/air partition coefficients have been found to be exponentially proportional to the reciprocal temperature, in agreement with theoretical expectations. Furthermore, in order to define the influence of different parameters on PAH adsorption on plant leaves, area and lipid leaf content were also measured. Results demonstrated that temperature plays a very important role in PAHs partitioning and that this value should be carefully considered during sampling, in order to obtain the best correlation between PAHs concentration in air and leaves.

Characterization of cytokinin signaling and homeostasis gene families in two hardwood tree species: Populus trichocarpa and Prunus persica.

Science.gov (United States)

Immanen, Juha; Nieminen, Kaisa; Duchens Silva, Héctor; Rodríguez Rojas, Fernanda; Meisel, Lee A; Silva, Herman; Albert, Victor A; Hvidsten, Torgeir R; Helariutta, Ykä

2013-12-16

Through the diversity of cytokinin regulated processes, this phytohormone has a profound impact on plant growth and development. Cytokinin signaling is involved in the control of apical and lateral meristem activity, branching pattern of the shoot, and leaf senescence. These processes influence several traits, including the stem diameter, shoot architecture, and perennial life cycle, which define the development of woody plants. To facilitate research about the role of cytokinin in regulation of woody plant development, we have identified genes associated with cytokinin signaling and homeostasis pathways from two hardwood tree species. Taking advantage of the sequenced black cottonwood (Populus trichocarpa) and peach (Prunus persica) genomes, we have compiled a comprehensive list of genes involved in these pathways. We identified genes belonging to the six families of cytokinin oxidases (CKXs), isopentenyl transferases (IPTs), LONELY GUY genes (LOGs), two-component receptors, histidine containing phosphotransmitters (HPts), and response regulators (RRs). All together 85 Populus and 45 Prunus genes were identified, and compared to their Arabidopsis orthologs through phylogenetic analyses. In general, when compared to Arabidopsis, differences in gene family structure were often seen in only one of the two tree species. However, one class of genes associated with cytokinin signal transduction, the CKI1-like family of two-component histidine kinases, was larger in both Populus and Prunus than in Arabidopsis.

Field performance of Populus in short-rotation intensive culture plantations in the north-central U.S.

Science.gov (United States)

Edward A. Hansen; Michael E. Ostry; Wendell D. Johnson; David N. Tolsted; Daniel A. Netzer; William E. Berguson; Richard B. Hall

1994-01-01

Describes a network of short-rotation, Populus research and demonstration plantations that has been established across a 5-state region in the north-central U.S. to identify suitable hybrid poplar clones for large-scale biomass plantations in the region. Reports 6-year results.

Use of belowground growing degree days to predict rooting of dormant hardwood cuttings of Populus

Science.gov (United States)

R.S., Jr. Zalesny; E.O. Bauer; D.E. Riemenschneider

2004-01-01

Planting Populus cuttings based on calendar days neglects soil temperature extremes and does not promote rooting based on specific genotypes. Our objectives were to: 1) test the biological efficacy of a thermal index based on belowground growing degree days (GDD) across the growing period, 2) test for interactions between belowground GDD and clones,...

Litter Quality of Populus Species as Affected by Free-Air CO2

OpenAIRE

Vermue, E.; Buurman, P.; Hoosbeek, M.R.

2009-01-01

The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter samples. Litter of P. euramerica was clearly different from that of P. nigra and P. alba. The latter two had higher contents of proteins, polysaccharides, and cutin/cutan, while the former had higher c...

DNA damage in Populus tremuloides clones exposed to elevated O3

International Nuclear Information System (INIS)

Tai, Helen H.; Percy, Kevin E.; Karnosky, David F.

2010-01-01

The effects of elevated concentrations of atmospheric tropospheric ozone (O 3 ) on DNA damage in five trembling aspen (Populus tremuloides Michx.) clones growing in a free-air enrichment experiment in the presence and absence of elevated concentrations of carbon dioxide (CO 2 ) were examined. Growing season mean hourly O 3 concentrations were 36.3 and 47.3 ppb for ambient and elevated O 3 plots, respectively. The 4th highest daily maximum 8-h ambient and elevated O 3 concentrations were 79 and 89 ppb, respectively. Elevated CO 2 averaged 524 ppm (+150 ppm) over the growing season. Exposure to O 3 and CO 2 in combination with O 3 increased DNA damage levels above background as measured by the comet assay. Ozone-tolerant clones 271 and 8L showed the highest levels of DNA damage under elevated O 3 compared with ambient air; whereas less tolerant clone 216 and sensitive clones 42E and 259 had comparably lower levels of DNA damage with no significant differences between elevated O 3 and ambient air. Clone 8L was demonstrated to have the highest level of excision DNA repair. In addition, clone 271 had the highest level of oxidative damage as measured by lipid peroxidation. The results suggest that variation in cellular responses to DNA damage between aspen clones may contribute to O 3 tolerance or sensitivity. - Ozone tolerant clones and sensitive Populus tremuloides clones show differences in DNA damage and repair.

Biochemical basis of drought tolerance in hybrid Populus grown under field production conditions. CRADA final report

Energy Technology Data Exchange (ETDEWEB)

Tschaplinski, T.J.; Tuskan, G.A. [Oak Ridge National Lab., TN (United States); Wierman, C. [Boise Cascade Corp., Wallula, WA (United States)

1997-04-01

The purpose of this cooperative effort was to assess the use of osmotically active compounds as molecular selection criteria for drought tolerance in Populus in a large-scale field trial. It is known that some plant species, and individuals within a plant species, can tolerate increasing stress associated with reduced moisture availability by accumulating solutes. The biochemical matrix of such metabolites varies among species and among individuals. The ability of Populus clones to tolerate drought has equal value to other fiber producers, i.e., the wood products industry, where irrigation is used in combination with other cultural treatments to obtain high dry weight yields. The research initially involved an assessment of drought stress under field conditions and characterization of changes in osmotic constitution among the seven clones across the six moisture levels. The near-term goal was to provide a mechanistic basis for clonal differences in productivity under various irrigation treatments over time.

Alternative splicing studies of the reactive oxygen species gene network in Populus reveal two isoforms of high-isoelectric-point superoxide dismutase.

Science.gov (United States)

Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

2009-04-01

Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays.

Semi-continuous anaerobic co-digestion of cow manure and steam-exploded Salix with recirculation of liquid digestate.

Science.gov (United States)

Estevez, Maria M; Sapci, Zehra; Linjordet, Roar; Schnürer, Anna; Morken, John

2014-04-01

The effects of recirculating the liquid fraction of the digestate during mesophilic anaerobic co-digestion of steam-exploded Salix and cow manure were investigated in laboratory-scale continuously stirred tank reactors. An average organic loading rate of 2.6 g VS L(-1) d(-1) and a hydraulic retention time (HRT) of 30 days were employed. Co-digestion of Salix and manure gave better methane yields than digestion of manure alone. Also, a 16% increase in the methane yield was achieved when digestate was recirculated and used instead of water to dilute the feedstock (1:1 dilution ratio). The reactor in which the larger fraction of digestate was recirculated (1:3 dilution ratio) gave the highest methane yields. Ammonia and volatile fatty acids did not reach inhibitory levels, and some potentially inhibitory compounds released during steam explosion (i.e., furfural and 5-hydroxy methyl furfural) were only detected at trace levels throughout the entire study period. However, accumulation of solids, which was more pronounced in the recycling reactors, led to decreased methane yields in those systems after three HRTs. Refraining from the use of fresh water to dilute biomass with a high-solids content and obtaining a final digestate with increased dry matter content might offer important economic benefits in full-scale processes. To ensure long-term stability in such an approach, it would be necessary to optimize separation of the fraction of digestate to be recirculated and also perform proper monitoring to avoid accumulation of solids. Copyright © 2014 Elsevier Ltd. All rights reserved.

Deserts in the Deluge: TerraPopulus and Big Human-Environment Data.

Science.gov (United States)

Manson, S M; Kugler, T A; Haynes, D

2016-01-01

Terra Populus, or TerraPop, is a cyberinfrastructure project that integrates, preserves, and disseminates massive data collections describing characteristics of the human population and environment over the last six decades. TerraPop has made a number of GIScience advances in the handling of big spatial data to make information interoperable between formats and across scientific communities. In this paper, we describe challenges of these data, or 'deserts in the deluge' of data, that are common to spatial big data more broadly, and explore computational solutions specific to microdata, raster, and vector data models.

Uptake and activity concentration of 137Cs and 90Sr in Salix viminalis

International Nuclear Information System (INIS)

Rosen, K.; Fircks, Y. von; Sennerby-Forsse, L.

1999-01-01

In order to gain a better understanding of the uptake, internal distribution of 137 Cs and 90 Sr and the effects of K-fertilisation of uptake of 137 Cs in Salix plantations, a K-fertilisation experiment including 137 Cs, 90 Sr and 40 K was performed. Previous studies with K-fertilization in Sweden have mainly dealt with the flow of 137 Cs between soil to plant in annual crops. The aim of this study was study the transfer of 137 Cs, 90 Sr and 40 K from soil to plants and to test the following hypothesis: that accumulation of 137 Cs and 90 Sr differs between plant organs, that there is a seasonal variation in uptake and concentration of 137 Cs and 90 Sr and that the availability of K is related to the uptake of 137 Cs. (au)

Formation of wood secondary cell wall may involve two type cellulose synthase complexes in Populus.

Science.gov (United States)

Xi, Wang; Song, Dongliang; Sun, Jiayan; Shen, Junhui; Li, Laigeng

2017-03-01

Cellulose biosynthesis is mediated by cellulose synthases (CesAs), which constitute into rosette-like cellulose synthase complexe (CSC) on the plasma membrane. Two types of CSCs in Arabidopsis are believed to be involved in cellulose synthesis in the primary cell wall and secondary cell walls, respectively. In this work, we found that the two type CSCs participated cellulose biosynthesis in differentiating xylem cells undergoing secondary cell wall thickening in Populus. During the cell wall thickening process, expression of one type CSC genes increased while expression of the other type CSC genes decreased. Suppression of different type CSC genes both affected the wall-thickening and disrupted the multilaminar structure of the secondary cell walls. When CesA7A was suppressed, crystalline cellulose content was reduced, which, however, showed an increase when CesA3D was suppressed. The CesA suppression also affected cellulose digestibility of the wood cell walls. The results suggest that two type CSCs are involved in coordinating the cellulose biosynthesis in formation of the multilaminar structure in Populus wood secondary cell walls.

Biomass traits and candidate genes for bioenergy revealed through association genetics in coppiced European Populus nigra (L.)

NARCIS (Netherlands)

Allwright, Mike Robert; Payne, Adrienne; Emiliani, Giovanni; Milner, Suzanne; Viger, Maud; Rouse, Franchesca; Keurentjes, Joost J.B.; Bérard, Aurélie; Wildhagen, Henning; Faivre-Rampant, Patricia; Polle, Andrea; Morgante, Michele; Taylor, Gail

2016-01-01

Background: Second generation (2G) bioenergy from lignocellulosic feedstocks has the potential to develop as a sustainable source of renewable energy; however, significant hurdles still remain for large-scale commercialisation. Populus is considered as a promising 2G feedstock and understanding

Hsf and Hsp gene families in Populus: genome-wide identification, organization and correlated expression during development and in stress responses.

Science.gov (United States)

Zhang, Jin; Liu, Bobin; Li, Jianbo; Zhang, Li; Wang, Yan; Zheng, Huanquan; Lu, Mengzhu; Chen, Jun

2015-03-14

Heat shock proteins (Hsps) are molecular chaperones that are involved in many normal cellular processes and stress responses, and heat shock factors (Hsfs) are the transcriptional activators of Hsps. Hsfs and Hsps are widely coordinated in various biological processes. Although the roles of Hsfs and Hsps in stress responses have been well characterized in Arabidopsis, their roles in perennial woody species undergoing various environmental stresses remain unclear. Here, a comprehensive identification and analysis of Hsf and Hsp families in poplars is presented. In Populus trichocarpa, we identified 42 paralogous pairs, 66.7% resulting from a whole genome duplication. The gene structure and motif composition are relatively conserved in each subfamily. Microarray and quantitative real-time RT-PCR analyses showed that most of the Populus Hsf and Hsp genes are differentially expressed upon exposure to various stresses. A coexpression network between Populus Hsf and Hsp genes was generated based on their expression. Coordinated relationships were validated by transient overexpression and subsequent qPCR analyses. The comprehensive analysis indicates that different sets of PtHsps are downstream of particular PtHsfs and provides a basis for functional studies aimed at revealing the roles of these families in poplar development and stress responses.

Transport and use of CO2 in the xylem sap of Populus deltoides

International Nuclear Information System (INIS)

Stringer, J.W.; Kimmerer, T.W.

1990-01-01

Results of recent experiments indicate an internal cycling of respiratory CO 2 in woody plants. The CO 2 concentration of xylem sap expressed from the twigs of field grown Populus deltoides ranged from .14 to .50 mM. The pH of the xylem sap was 5.7 to 6.7, providing a significant bicarbonate concentration in many samples. Total dissolved inorganic carbon (DIC = CO 2 + H 2 CO 3 + HCO 3 - ) was 0.5 mM to 1.3 mM. Results from the analysis of xylem sap of 10 other species of woody plants were similar. To determine the fate of DIC delivered to the leaves of Populus deltoides, excised leaves were fed 1mM NaHCO 3 (2 μCi NaH 14 CO 3 ml -1 ). Less than 0.4% of the label escaped from the leaves, and ≥93% was fixed. Of the carbon fixed 56% of the 14 C was found in the petiole and midrib, and 14% was in the major veins, with the remaining 30% in the minor veins and lamina. Shading of the peptiole and midrib of leaves decreased the amount of fixed carbon in these tissues to 38% and increased the amount in the lamina to 55%

Generalized allometric regression to estimate biomass of Populus in short-rotation coppice

Energy Technology Data Exchange (ETDEWEB)

Ben Brahim, Mohammed; Gavaland, Andre; Cabanettes, Alain [INRA Centre de Toulouse, Castanet-Tolosane Cedex (France). Unite Agroforesterie et Foret Paysanne

2000-07-01

Data from four different stands were combined to establish a single generalized allometric equation to estimate above-ground biomass of individual Populus trees grown on short-rotation coppice. The generalized model was performed using diameter at breast height, the mean diameter and the mean height of each site as dependent variables and then compared with the stand-specific regressions using F-test. Results showed that this single regression estimates tree biomass well at each stand and does not introduce bias with increasing diameter.

Cytogenetic Analysis of Populus trichocarpa - Ribosomal DNA, Telomere Repeat Sequence, and Marker-selected BACs

Science.gov (United States)

M.N. lslam-Faridi; C.D. Nelson; S.P. DiFazio; L.E. Gunter; G.A. Tuskan

2009-01-01

The 185-285 rDNA and 55 rDNA loci in Populus trichocarpa were localized using fluorescent in situ hybridization (FISH). Two 185-285 rDNA sites and one 55 rDNA site were identified and located at the ends of 3 different chromosomes. FISH signals from the Arabidopsis-type telomere repeat sequence were observed at the distal ends of each chromosome. Six BAC clones...

Inheritance of compartmentalization of wounds in sweetgum (Liquidambar styraciflua L.) and eastern cottonwood (Populus deltoides Bartr.)

Science.gov (United States)

P. W. Garrett; W. K. Randall; A. L. Shigo; W. C. Shortle

1979-01-01

Studies of half-sib progeny tests of sweetgum (Liquidambar styraciflua) and clonal plantings of eastern cottonwood (Populus deltoides) in Mississippi indicate that rate of wound closure and size of discolored columns associated with the wounds are both heritable traits. Both are independent of stem diameter, which was used as a...

Examination of correlation between histidine and nickel absorption by Morus L., Robinia pseudoacacia L. and Populus nigra L. using HPLC-MS and ICP-MS.

Science.gov (United States)

Ozen, Sukran Akkus; Yaman, Mehmet

2016-08-02

In this study, HPLC-MS and ICP-MS methods were used for the determination of histidine and nickel in Morus L., Robinia pseudoacacia L., and Populus nigra L. leaves taken from industrial areas including Gaziantep and Bursa cities. In the determination of histidine by HPLC-MS, all of the system parameters such as flow rate of mobile phase, fragmentor potential, injection volume and column temperature were optimized and found to be 0.2 mL min(-1), 70 V, 15 µL, and 20°C, respectively. Under the optimum conditions, histidine was extracted from plant sample by distilled water at 90°C for 30 min. Concentrations of histidine as mg kg(-1) were found to be between 2-9 for Morus L., 6-13 for Robinia pseudoacacia L., and 2-10 for Populus nigra L. Concentrations of nickel were in the ranges of 5-10 mg kg(-1) for Morus L., 3-10 mg kg(-1) for Robinia pseudoacacia L., and 0.6-4 mg kg(-1) for Populus nigra L. A significant linear correlation (r = 0.78) between histidine and Ni was observed for Populus nigra L., whereas insignificant linear correlation for Robinia pseudoacacia L. (r = 0.22) were seen. Limits of detection (LOD) and quantitation (LOQ) were found to be 0.025 mg Ni L(-1) and 0.075 mg Ni L(-1), respectively.

Phytoextraction potential of poplar (Populus alba L. var. pyramidalis Bunge) from calcareous agricultural soils contaminated by cadmium.

Science.gov (United States)

Hu, Yahu; Nan, Zhongren; Jin, Cheng; Wang, Ning; Luo, Huanzhang

2014-01-01

To investigate the phytoextraction potential of Populus alba L. var. pyramidalis Bunge for cadmium (Cd) contaminated calcareous soils, a concentration gradient experiment and a field sampling experiment (involving poplars of different ages) were conducted. The translocation factors for all experiments and treatments were greater than 1. The bioconcentration factor decreased from 2.37 to 0.25 with increasing soil Cd concentration in the concentration gradient experiment and generally decreased with stand age under field conditions. The Cd concentrations in P. pyramidalis organs decreased in the order of leaves > stems > roots. The shoot biomass production in the concentration gradient experiment was not significantly reduced with soil Cd concentrations up to or slightly over 50 mg kg(-1). The results show that the phytoextraction efficiency of P. pyramidalis depends on both the soil Cd concentration and the tree age. Populus pyramidalis is most suitable for remediation of slightly Cd contaminated calcareous soils through the combined harvest of stems and leaves under actual field conditions.

Salix response to different flow regimes in controlled experiments: first results

Science.gov (United States)

Gorla, Lorenzo; Signarbieux, Constant; Buttler, Alexandre; Perona, Paolo

2013-04-01

Dams and water management for hydropower production, agriculture and other human activities alter the natural flow regime of rivers. The new river hydrograph components depend on the type of impoundment and the policy of regulation but such a different flow regime will likely affect the riparian environment. The main challenge in order to define sustainable flow releases is to quantify hydrological effects in terms of geomorphology and ecosystem response. A considerable lack of knowledge still affects the link hydrology-ecology and inadequate flow rules (e.g., minimal or residual flows) are consequently still widespread: further research in this direction is urgently required. We present an experiment, which aims to investigate the effects of different water stage regimes on riparian vegetation (salix Viminalis cuttings) development in a temperate region (Switzerland). This work describes the installation setup, together with the first results concerning the first of the two scheduled seasons of campaign. Sixty Salix cuttings were planted in non-cohesive sandy-gravel sediment within 1 meter tall plastic pots installed outside in the EPFL campus. After grouping them in three batteries, the water level within them has been varying following three river regimes simulated by adjusting the water level within the pots by means of an automatic hydraulic system. The three water level regimes reproduce a natural flow regime, a minimum residual flow policy, which only conserves peaks during flooding conditions, and an artificial regime conserving only low frequencies (e.g., seasonality) of the natural dynamic. The natural flow regime of the first battery has been applied for two months to the entire system; the three regimes above said started in June 2012. This triggered a plant response transitory regime, which we monitored by measuring plant growth, soil and atmospheric variables. Particularly, measures concern with branches development leaves photosynthesis and

Expression of zinc and cadmium responsive genes in leaves of willow (Salix caprea L.) genotypes with different accumulation characteristics

International Nuclear Information System (INIS)

Konlechner, Cornelia; Türktaş, Mine; Langer, Ingrid; Vaculík, Marek; Wenzel, Walter W.; Puschenreiter, Markus; Hauser, Marie-Theres

2013-01-01

Salix caprea is well suited for phytoextraction strategies. In a previous survey we showed that genetically distinct S. caprea plants isolated from metal-polluted and unpolluted sites differed in their zinc (Zn) and cadmium (Cd) tolerance and accumulation abilities. To determine the molecular basis of this difference we examined putative homologues of genes involved in heavy metal responses and identified over 200 new candidates with a suppression subtractive hybridization (SSH) screen. Quantitative expression analyses of 20 genes in leaves revealed that some metallothioneins and cell wall modifying genes were induced irrespective of the genotype's origin and metal uptake capacity while a cysteine biosynthesis gene was expressed constitutively higher in the metallicolous genotype. The third and largest group of genes was only induced in the metallicolous genotype. These data demonstrate that naturally adapted woody non-model species can help to discover potential novel molecular mechanisms for metal accumulation and tolerance. -- Highlights: ► The transcriptional Zn/Cd response of the willow Salix caprea was quantified. ► Two genotypes from a highly contaminated and a control environment were compared. ► In addition to candidate genes an SSH library revealed over 200 metal induced genes. ► Constitutive upregulation and isolate-specific induction of genes were revealed. ► Willows adapt to environmental Zn/Cd contamination on the transcriptional level. -- Expression analyzes reveal different responses to Cd and Zn exposure of S. caprea genotypes with different heavy metal accumulation abilities

Salix daphnoides: A Screening for Oligomeric and Polymeric Proanthocyanidins

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Stefan Wiesneth

2015-07-01

Full Text Available In the present study, a qualitative analysis of proanthocyanidins (PAs from an aqueous-methanolic extract of Salix daphnoides VILL. bark is described. Procyanidin B1 (1, B2 (2, B3 (3, B4 (4, C1 (5, epicatechin-(4β→8-epicatechin-(4β→8-catechin (6 and epicatechin-(4β→8-epicatechin-(4β→8-epicatechin-(4β→8-catechin (7 have been isolated by a combination of different chromatographic separations on Sephadex® LH-20-, MCI®-, Diol-and RP-18-phases. Mass spectrometry, 1D- and 2D-NMR, circular dichroism and polarimetry were used for their structure elucidation and verification by comparison with the literature. Additionally, two fractions of very polar flavan-3-ols were compared: “regular” polymeric PAs received at the very end of the Sephadex® LH-20 chromatography showing no mobility on silica TLC and “unusual” PAs with the same RF-value but already eluting together with flavonoids in the Sephadex® LH-20 system. These “unusual” PAs were subsequently enriched by centrifugal partition chromatography (CPC. 13C-NMR, polarimetry, thiolysis, acid hydrolysis and phloroglucinol degradation were used to characterize both fractions. Differences in the composition of different flavan-3-ol units and the middle chain length were observed.

Groundwater–surface water interactions, vegetation dependencies and implications for water resources management in the semi-arid Hailiutu River catchment, China – a synthesis

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Y. Zhou

2013-07-01

Full Text Available During the last decades, large-scale land use changes took place in the Hailiutu River catchment, a semi-arid area in northwest China. These changes had significant impacts on the water resources in the area. Insights into groundwater and surface water interactions and vegetation-water dependencies help to understand these impacts and formulate sustainable water resources management policies. In this study, groundwater and surface water interactions were identified using the baseflow index at the catchment scale, and hydraulic and water temperature methods as well as event hydrograph separation techniques at the sub-catchment scale. The results show that almost 90% of the river discharge consists of groundwater. Vegetation dependencies on groundwater were analysed from the relationship between the Normalized Difference Vegetation Index (NDVI and groundwater depth at the catchment scale and along an ecohydrogeological cross-section, and by measuring the sap flow of different plants, soil water contents and groundwater levels at different research sites. The results show that all vegetation types, i.e. trees (willow (Salix matsudana and poplar (Populus simonii, bushes (salix – Salix psammophila, and agricultural crops (maize – Zea mays, depend largely on groundwater as the source for transpiration. The comparative analysis indicates that maize crops use the largest amount of water, followed by poplar trees, salix bushes, and willow trees. For sustainable water use with the objective of satisfying the water demand for socio-economical development and to prevent desertification and ecological impacts on streams, more water-use-efficient crops such as sorghum, barley or millet should be promoted to reduce the consumptive water use. Willow trees should be used as wind-breaks in croplands and along roads, and drought-resistant and less water-use intensive plants (for instance native bushes should be used to vegetate sand dunes.

New Rust Disease of Korean Willow (Salix koreensis) Caused by Melampsora yezoensis, Unrecorded Pathogen in Korea.

Science.gov (United States)

Yun, Yeo Hong; Ahn, Geum Ran; Yoon, Seong Kwon; Kim, Hoo Hyun; Son, Seung Yeol; Kim, Seong Hwan

2016-12-01

During the growing season of 2015, leaf specimens with yellow rust spots were collected from Salix koreensis Andersson, known as Korean willow, in riverine areas in Cheonan, Korea. The fungus on S. koreensis was identified as the rust species, Melampsora yezoensis , based on the morphology of urediniospores observed by light and scanning electron microscopy, and the molecular properties of the internal transcribed spacer rDNA region. Pathogenicity tests confirmed that the urediniospores are the causal agent of the rust symptoms on the leaves and young stems of S. koreensis . Here, we report a new rust disease of S. koreensis caused by the rust fungus, M. yezoensis , a previously unrecorded rust pathogen in Korea.

Macro- and micro-nutrient concentration in leaf, woody, and root tissue of Populus irrigated with landfill leachate

Science.gov (United States)

Jill A. Zalesny; Ronald S., Jr. Zalesny; Adam H. Wiese; Bart T. Sexton; Richard B. Hall

2007-01-01

Landfill leachate offers an opportunity to supply water and plant nutritional benefits at a lower cost than traditional sources. Information about nutrient uptake and distribution into tissues of Populus irrigated with landfill leachate helps increase biomass production along with evaluating the impacts of leachate chemistry on tree health.

Geochemical peculiarities of black poplar leaves (Populus nigra L.) in the sites with heavy metals intensive fallouts

Science.gov (United States)

Yalaltdinova, Albina; Baranovskaya, Natalya; Rikhvanov, Leonid; Matveenko, Irina

2013-04-01

The article deals with the content of 28 chemical elements in the leaves ash of black poplar (Populus nigra L.) growing in Ust-Kamenogorsk city area. It is the major industrial center of Kazakhstan Republic on the territory where the industrial giants of non-ferrous metallurgy and nuclear energy are situated. Comparative analysis with the similar data obtained from leaves ash of Populus nigra L. in Tomsk, Ekibastuz, and Pavlodar cities has revealed that in comparison with other urban areas, leaves ash of black poplar (Populus nigra L.) from Ust-Kamenogorsk city is characterized by elevated concentration rates of Ta, U, Zn, Ag, As, Sb, Br, Sr and Na. Within the city, the sites and areas with abnormal contents of typomorphic pollutants have been revealed. In the central part of the city, in the vicinity of lead-zinc plant and Ulba metallurgical plant, the highest concentrations of Ta, U, Zn, Ag, Au, As, Sb, Cr and Fe were marked. In the northeast, where the titanium-magnesium plant is located, elevated concentrations of Br and Sr were stated. Thus, the impact of major city enterprises which are the main sources of heavy metals is reflected in the element composition. Zn, As, Sb, Ag and Au comes from lead-zinc plant and its refinery plants, while Ulba metallurgical plant can be considered source of Ta and U in the environment, producing tantalum and fuel pellets for nuclear power plants. These companies, due to the current objective circumstances, are located in the central part of the city, have a significant negative effect on the environment and form the risk factors for human health.

Comparative physiology of allopatric Populus species: Geographic clines in photosynthesis, height growth and carbon isotope discrimination in common gardens

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Raju Yaranna Soolanayakanahally

2015-07-01

Full Text Available Populus species with wide geographic ranges display strong adaptation to local environments. We studied the clinal patterns in phenology and ecophysiology in allopatric Populus species adapted to similar environments on different continents under common garden settings. As a result of climatic adaptation, both P. tremula L. and Populus balsamifera L. display latitudinal clines in photosynthetic rates (A, whereby high-latitude trees of P. tremula had higher A compared to low-latitude trees and nearly so in P. balsamifera (p = 0.06. Stomatal conductance (gs and chlorophyll content index (CCI follow similar latitudinal trends. However, foliar nitrogen was positively correlated with latitude in P. balsamifera and negatively correlated in P. tremula. No significant trends in carbon isotope composition of the leaf tissue (δ13C were observed for both species; but, intrinsic water-use efficiency (WUEi was negatively correlated with the latitude of origin in P. balsamifera. In spite of intrinsically higher A, high-latitude trees in both common gardens accomplished less height gain as a result of early bud set. Thus, shoot biomass was determined by height elongation duration (HED, which was well approximated by the number of days available for free growth between bud flush and bud set. In doing so, we highlight the shortcoming of unreplicated outdoor common gardens for tree improvement and the crucial role of photoperiod in limiting height growth, further complicating interpretation of other secondary effects.

Increased leaf area dominates carbon flux response to elevated CO2 in stands of Populus deltoides (Bartr.)

Science.gov (United States)

Ramesh Murthy; Greg Barron-Gafford; Philip M. Dougherty; Victor c. Engels; Katie Grieve; Linda Handley; Christie Klimas; Mark J. Postosnaks; Stanley J. Zarnoch; Jianwei Zhang

2005-01-01

We examined the effects of atmospheric vapor pressure deficit (VPD) and soil moisture stress (SMS) on leaf- and stand-level CO2 exchange in model 3-year-old coppiced cottonwood (Populus deltoides Bartr.) plantations using the large-scale, controlled environments of the Biosphere 2 Laboratory. A short-term experiment was imposed...

Woody biomass phytoremediation of contaminated brownfield land

Energy Technology Data Exchange (ETDEWEB)

French, Christopher J. [School of Biological and Earth Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom); Dickinson, Nicholas M. [School of Biological and Earth Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF (United Kingdom)]. E-mail: n.m.dickinson@livjm.ac.uk; Putwain, Philip D. [Ecological Restoration Consultants (ERC), Ness Botanic Gardens, University of Liverpool, Ness, Cheshire CH64 (United Kingdom)

2006-06-15

Economic and environmental regeneration of post-industrial landscapes frequently involves some element of re-afforestation or tree planting. We report field trials that evaluate whether woody biomass production is compatible with managing residual trace element contamination in brownfield soils. Large-scale mapping of contamination showed a heterogenous dispersion of metals and arsenic, and highly localised within-site hotspots. Yields of Salix, Populus and Alnus were economically viable, showing that short-rotation coppice has a potentially valuable role in community forestry. Mass balance modelling demonstrated that phytoextraction potentially could reduce contamination hotspots of more mobile elements (Cd and Zn) within a 25-30-year life cycle of the crops. Cd and Zn in stems and foliage of Salix were 4-13 times higher than EDTA-extractable soil concentrations. Lability of other trace elements (As, Pb, Cu, Ni) was not increased 3 years after planting the coppice; woody biomass may provide an effective reduction of exposure (phytostabilisation) to these less mobile contaminants. - Field trials show short-rotation coppice provides effective risk management and remediation solutions to hotspots of residual metal and As contamination of brownfield land.

Woody biomass phytoremediation of contaminated brownfield land

International Nuclear Information System (INIS)

French, Christopher J.; Dickinson, Nicholas M.; Putwain, Philip D.

2006-01-01

Economic and environmental regeneration of post-industrial landscapes frequently involves some element of re-afforestation or tree planting. We report field trials that evaluate whether woody biomass production is compatible with managing residual trace element contamination in brownfield soils. Large-scale mapping of contamination showed a heterogenous dispersion of metals and arsenic, and highly localised within-site hotspots. Yields of Salix, Populus and Alnus were economically viable, showing that short-rotation coppice has a potentially valuable role in community forestry. Mass balance modelling demonstrated that phytoextraction potentially could reduce contamination hotspots of more mobile elements (Cd and Zn) within a 25-30-year life cycle of the crops. Cd and Zn in stems and foliage of Salix were 4-13 times higher than EDTA-extractable soil concentrations. Lability of other trace elements (As, Pb, Cu, Ni) was not increased 3 years after planting the coppice; woody biomass may provide an effective reduction of exposure (phytostabilisation) to these less mobile contaminants. - Field trials show short-rotation coppice provides effective risk management and remediation solutions to hotspots of residual metal and As contamination of brownfield land

Effects of ambient versus reduced UV-B radiation on high arctic ¤Salix arctica¤ assessed by measurements and calculations of chlorophyll a fluorescence parameters from fluorescence transients

DEFF Research Database (Denmark)

Albert, K.R.; Mikkelsen, Teis Nørgaard; Ro-Poulsen, H.

2005-01-01

A UV-B exclusion-experiment was conducted in the high arctic Zackenberg, NE Greenland, in which Salix arctica leaves during most of the growing season were fixed perpendicular to the solar zenith angle, thereby receiving maximal solar radiation. Covered with Teflon and Mylar foil, the leaves...

Ambient UV-B radiation reduces PSII performance and net photosynthesis in high Arctic Salix arctica

DEFF Research Database (Denmark)

Albert, Kristian Rost; Mikkelsen, Teis Nørgaard; Ro-Poulsen, Helge

2011-01-01

Ambient ultraviolet-B (UV-B) radiation potentially impacts the photosynthetic performance of high Arctic plants. We conducted an UV-B exclusion experiment in a dwarf shrub heath in NE Greenland (74°N), with open control, filter control, UV-B filtering and UV-AB filtering, all in combination......, nitrogen and UV-B absorbing compounds. Compared to a 60% reduced UV-B irradiance, the ambient solar UV-B reduced net photosynthesis in Salix arctica leaves fixed in the 45° position which exposed leaves to maximum natural irradiance. Also a reduced Calvin Cycle capacity was found, i.e. the maximum rate...... across position in the vegetation. These findings add to the evidence that the ambient solar UV-B currently is a significant stress factor for plants in high Arctic Greenland....

Date of shoot collection, genotype, and original shoot position affect early rooting of dormant hardwood cuttings of Populus

Science.gov (United States)

R. S., Jr. Zalesny; A.H. Wiese

2006-01-01

Identifying superior combinations among date of dormant- season shoot collection, genotype, and original shoot position can increase the rooting potential of Populus cuttings. Thus, the objectives of our study were to: 1) evaluate variation among clones in early rooting from hardwood cuttings processed every three weeks from shoots collected...

In vitro regeneration of Salix nigra from adventitious shoots.

Science.gov (United States)

Lyyra, Satu; Lima, Amparo; Merkle, Scott A

2006-07-01

Black willow (Salix nigra Marsh.) is the largest and only commercially important willow species in North America. It is a candidate for phytoremediation of polluted soils because it is fast-growing and thrives on floodplains throughout eastern USA. Our objective was to develop a protocol for the in vitro regeneration of black willow plants that could serve as target material for gene transformation. Unexpanded inflorescence explants were excised from dormant buds collected from three source trees and cultured on woody plant medium (WPM) supplemented with one of: (1) 0.1 mg l(-1) thidiazuron (TDZ); (2) 0.5 mg l(-1) 6-benzoaminopurine (BAP); or (3) 1 mg l(-1) BAP. All plant growth regulator (PGR) treatments induced direct adventitious bud formation from the genotypes. The percentage of explants producing buds ranged from 20 to 92%, depending on genotype and treatment. Although most of the TDZ-treated inflorescences produced buds, these buds failed to elongate into shoots. Buds on explants treated with BAP elongated into shoots that were easily rooted in vitro and further established in potting mix in high humidity. The PGR treatments significantly affected shoot regeneration frequency (P < 0.01). The highest shoot regeneration frequency (36%) was achieved with Genotype 3 cultured on 0.5 mg l(-1) BAP. Mean number of shoots per explant varied from one to five. The ability of black willow inflorescences to produce adventitious shoots makes them potential targets for Agrobacterium-mediated transformation with heavy-metal-resistant genes for phytoremediation.

Alternative Splicing Studies of the Reactive Oxygen Species Gene Network in Populus Reveal Two Isoforms of High-Isoelectric-Point Superoxide Dismutase1[C][W

Science.gov (United States)

Srivastava, Vaibhav; Srivastava, Manoj Kumar; Chibani, Kamel; Nilsson, Robert; Rouhier, Nicolas; Melzer, Michael; Wingsle, Gunnar

2009-01-01

Recent evidence has shown that alternative splicing (AS) is widely involved in the regulation of gene expression, substantially extending the diversity of numerous proteins. In this study, a subset of expressed sequence tags representing members of the reactive oxygen species gene network was selected from the PopulusDB database to investigate AS mechanisms in Populus. Examples of all known types of AS were detected, but intron retention was the most common. Interestingly, the closest Arabidopsis (Arabidopsis thaliana) homologs of half of the AS genes identified in Populus are not reportedly alternatively spliced. Two genes encoding the protein of most interest in our study (high-isoelectric-point superoxide dismutase [hipI-SOD]) have been found in black cottonwood (Populus trichocarpa), designated PthipI-SODC1 and PthipI-SODC2. Analysis of the expressed sequence tag libraries has indicated the presence of two transcripts of PthipI-SODC1 (hipI-SODC1b and hipI-SODC1s). Alignment of these sequences with the PthipI-SODC1 gene showed that hipI-SODC1b was 69 bp longer than hipI-SODC1s due to an AS event involving the use of an alternative donor splice site in the sixth intron. Transcript analysis showed that the splice variant hipI-SODC1b was differentially expressed, being clearly expressed in cambial and xylem, but not phloem, regions. In addition, immunolocalization and mass spectrometric data confirmed the presence of hipI-SOD proteins in vascular tissue. The functionalities of the spliced gene products were assessed by expressing recombinant hipI-SOD proteins and in vitro SOD activity assays. PMID:19176719

Sex-specific responses to winter flooding, spring waterlogging and post-flooding recovery in Populus deltoides

OpenAIRE

Ling-Feng Miao; Fan Yang; Chun-Yu Han; Yu-Jin Pu; Yang Ding; Li-Jia Zhang

2017-01-01

Winter flooding events are common in some rivers and streams due to dam constructions, and flooding and waterlogging inhibit the growth of trees in riparian zones. This study investigated sex-specific morphological, physiological and ultrastructural responses to various durations of winter flooding and spring waterlogging stresses, and post-flooding recovery characteristics in Populus deltoides. There were no significant differences in the morphological, ultrastructural and the majority of ph...

Expression Patterns of ERF Genes Underlying Abiotic Stresses in Di-Haploid Populus simonii × P. nigra

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Shengji Wang

2014-01-01

Full Text Available 176 ERF genes from Populus were identified by bioinformatics analysis, 13 of these in di-haploid Populus simonii × P. nigra were investigate by real-time RT-PCR, the results demonstrated that 13 ERF genes were highly responsive to salt stress, drought stress and ABA treatment, and all were expressed in root, stem, and leaf tissues, whereas their expression levels were markedly different in the various tissues. In roots, PthERF99, 110, 119, and 168 were primarily downregulated under drought and ABA treatment but were specifically upregulated under high salt condition. Interestingly, in poplar stems, all ERF genes showed the similar trends in expression in response to NaCl stress, drought stress, and ABA treatment, indicating that they may not play either specific or unique roles in stems in abiotic stress responses. In poplar leaves, PthERF168 was highly induced by ABA treatment, but was suppressed by high salinity and drought stresses, implying that PthERF168 participated in the ABA signaling pathway. The results of this study indicated that ERF genes could play essential but distinct roles in various plant tissues in response to different environment cues and hormonal treatment.

Effects of light regime and IBA concentration on adventitious rooting of an eastern cottonwood (Populus deltoides) clone

Science.gov (United States)

Alexander P. Hoffman; Joshua P. Adams; Andrew Nelson

2016-01-01

Eastern cottonwood (Populus deltoides) has received a substantial amount of interest from invitro studies within the past decade. The ability to efficiently multiply the stock of established clones such as clone 110412 is a valuable asset for forest endeavors. However, a common problem encountered is initiating adventitious rooting in new micropropagation protocols....

Salix transect of Europe: variation in ploidy and genome size in willow-associated common nettle, Urtica dioica L. sens. lat., from Greece to arctic Norway.

Science.gov (United States)

Cronk, Quentin; Hidalgo, Oriane; Pellicer, Jaume; Percy, Diana; Leitch, Ilia J

2016-01-01

The common stinging nettle, Urtica dioica L. sensu lato, is an invertebrate "superhost", its clonal patches maintaining large populations of insects and molluscs. It is extremely widespread in Europe and highly variable, and two ploidy levels (diploid and tetraploid) are known. However, geographical patterns in cytotype variation require further study. We assembled a collection of nettles in conjunction with a transect of Europe from the Aegean to Arctic Norway (primarily conducted to examine the diversity of Salix and Salix -associated insects). Using flow cytometry to measure genome size, our sample of 29 plants reveals 5 diploids and 24 tetraploids. Two diploids were found in SE Europe (Bulgaria and Romania) and three diploids in S. Finland. More detailed cytotype surveys in these regions are suggested. The tetraploid genome size (2C value) varied between accessions from 2.36 to 2.59 pg. The diploids varied from 1.31 to 1.35 pg per 2C nucleus, equivalent to a haploid genome size of c. 650 Mbp. Within the tetraploids, we find that the most northerly samples (from N. Finland and arctic Norway) have a generally higher genome size. This is possibly indicative of a distinct population in this region.

Ex situ growth and biomass of Populus bioenergy crops irrigated and fertilized with landfill leachate

International Nuclear Information System (INIS)

Zalesny, Ronald S.; Wiese, Adam H.; Bauer, Edmund O.; Riemenschneider, Donald E.

2009-01-01

Merging traditional intensive forestry with waste management offers dual goals of fiber and bioenergy production, along with environmental benefits such as soil/water remediation and carbon sequestration. As part of an ongoing effort to acquire data about initial genotypic performance, we evaluated: (1) the early aboveground growth of trees belonging to currently utilized Populus genotypes subjected to irrigation with municipal solid waste landfill leachate or non-fertilized well water (control), and (2) the above- and below-ground biomass of the trees after 70 days of growth. We determined height, diameter, and number of leaves at 28, 42, 56, and 70 days after planting (DAP), along with stem, leaf, and root dry mass by testing six Populus clones (DN34, DN5, I4551, NC14104, NM2, NM6) grown in a greenhouse in a split-split plot, repeated measures design with two blocks, two treatments (whole-plots), six clones (sub-plots), and four sampling dates (sub-sub-plots, repeated measure). Treatments (leachate, water) were applied every other day beginning 42 DAP. The leachate-treated trees exhibited greater height, diameter, and number of leaves at 56 and 70 DAP (P 0.05). Overall, genotypic responses to the leachate treatment were clone-specific for all traits

Gene Structures, Classification, and Expression Models of the DREB Transcription Factor Subfamily in Populus trichocarpa

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Yunlin Chen

2013-01-01

Full Text Available We identified 75 dehydration-responsive element-binding (DREB protein genes in Populus trichocarpa. We analyzed gene structures, phylogenies, domain duplications, genome localizations, and expression profiles. The phylogenic construction suggests that the PtrDREB gene subfamily can be classified broadly into six subtypes (DREB A-1 to A-6 in Populus. The chromosomal localizations of the PtrDREB genes indicated 18 segmental duplication events involving 36 genes and six redundant PtrDREB genes were involved in tandem duplication events. There were fewer introns in the PtrDREB subfamily. The motif composition of PtrDREB was highly conserved in the same subtype. We investigated expression profiles of this gene subfamily from different tissues and/or developmental stages. Sixteen genes present in the digital expression analysis had high levels of transcript accumulation. The microarray results suggest that 18 genes were upregulated. We further examined the stress responsiveness of 15 genes by qRT-PCR. A digital northern analysis showed that the PtrDREB17, 18, and 32 genes were highly induced in leaves under cold stress, and the same expression trends were shown by qRT-PCR. Taken together, these observations may lay the foundation for future functional analyses to unravel the biological roles of Populus’ DREB genes.

Treatment of a Textile Effluent by Electrochemical Oxidation and Coupled System Electooxidation–Salix babylonica

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Alejandra Sánchez-Sánchez

2018-01-01

Full Text Available The removal of pollutants from textile wastewater via electrochemical oxidation and a coupled system electrooxidation—Salix babylonica, using boron-doped diamond electrodes was evaluated. Under optimal conditions of pH 5.23 and 3.5 mA·cm−2 of current density, the electrochemical method yields an effective reduction of chemical oxygen demand by 41.95%, biochemical oxygen demand by 83.33%, color by 60.83%, and turbidity by 26.53% at 300 minutes of treatment. The raw and treated wastewater was characterized by infrared spectroscopy to confirm the degradation of pollutants. The wastewater was oxidized at 15-minute intervals for one hour and was placed in contact with willow plants for 15 days. The coupled system yielded a reduction of the chemical oxygen demand by 14%, color by 85%, and turbidity by 93%. The best efficiency for the coupled system was achieved at 60 minutes, at which time the plants achieved more biomass and photosynthetic pigments.

Stem Photosynthesis of Twig and Its Contribution to New Organ Development in Cutting Seedlings of Salix Matsudana Koidz.

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Junxiang Liu

2018-04-01

Full Text Available The objective of this study was to illustrate the photosynthetic characteristics of current twigs of Salix matsudana Koidz., and clarify the effect of stem photosynthesis on the new organ development in cutting seedlings. Excised twigs were taken as the experimental samples. The response of the stem photosynthesis rate to increasing light intensity and the effective photochemical efficiency of the cross section of the twig were determined. Then, twigs were used as cuttings and exposed to 0, 20, and 100 μmol m−2 s−1 light intensities, respectively, to achieve distinctive stem photosynthetic rates. After 14 days of treatment, stem water and non-structural carbohydrate (NSC content, as well as the biomass and carbon isotopic composition, of new organs in the cutting seedlings under different light treatments were examined. The results showed that the gross photosynthetic rate significantly increased within 400 μmol m−2 s−1 of light intensity, and the maximum rate was approximately 1.27 μmol m−2 s−1. The effective photochemical efficiency of the PSⅡ of the cortex was significantly higher than the inner tissues in the cross section of the twig. When twig cuttings were exposed to different light intensities, stem water and starch content, as well as bud and root biomass, were significantly higher in the cutting seedling subjected to 100 μmol m−2 s−1 than the case treated in darkness; however, the bud δ13C trend was the opposite. Stem photosynthesis played a positive role in the maintenance of stem water and starch supply for the cutting seedlings, and 13C depleted assimilates produced by stem photosynthesis contributed to bud biomass, revealing that stem photosynthesis promotes organ development in cutting seedlings of Salix matsudana.

Early Events in Populus Hybrid and Fagus sylvatica Leaves Exposed to Ozone

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R. Desotgiu

2010-01-01

Full Text Available This paper aims to investigate early responses to ozone in leaves of Fagus sylvatica (beech and Populus maximowiczii x Populus berolinensis (poplar. The experimental setup consisted of four open-air (OA plots, four charcoal-filtered (CF open-top chambers (OTCs, and four nonfiltered (NF OTCs. Qualitative and quantitative analyses were carried out on nonsymptomatic (CF and symptomatic (NF and OA leaves of both species. Qualitative analyses were performed applying microscopic techniques: Evans blue staining for detection of cell viability, CeCl3 staining of transmission electron microscope (TEM samples to detect the accumulation of H2O2, and multispectral fluorescence microimaging and microspectrofluorometry to investigate the accumulation of fluorescent phenolic compounds in the walls of the damaged cells. Quantitative analyses consisted of the analysis of the chlorophyll a fluorescence transients (fast kinetics. The early responses to ozone were demonstrated by the Evans blue and CeCl3 staining techniques that provided evidence of plant responses in both species 1 month before foliar symptoms became visible. The fluorescence transients analysis, too, demonstrated the breakdown of the oxygen evolving system and the inactivation of the end receptors of electrons at a very early stage, both in poplar and in beech. The accumulation of phenolic compounds in the cell walls, on the other hand, was a species-specific response detected in poplar, but not in beech. Evans blue and CeCl3 staining, as well as the multispectral fluorescence microimaging and microspectrofluorometry, can be used to support the field diagnosis of ozone injury, whereas the fast kinetics of chlorophyll fluorescence provides evidence of early physiological responses.

Genetic origin and composition of a natural hybrid poplar Populus???jrtyschensis from two distantly related species

OpenAIRE

Jiang, Dechun; Feng, Jianju; Dong, Miao; Wu, Guili; Mao, Kangshan; Liu, Jianquan

2016-01-01

Background The factors that contribute to and maintain hybrid zones between distinct species are highly variable, depending on hybrid origins, frequencies and fitness. In this study, we aimed to examine genetic origins, compositions and possible maintenance of Populus???jrtyschensis, an assumed natural hybrid between two distantly related species. This hybrid poplar occurs mainly on the floodplains along the river valleys between the overlapping distributions of the two putative parents. Resu...

PROCESS OPTIMIZATION OF TETRA ACETYL ETHYLENE DIAMINE ACTIVATED HYDROGEN PEROXIDE BLEACHING OF POPULUS NIGRA CTMP

OpenAIRE

Qiang Zhao; Junwen Pu; Shulei Mao; Guibo Qi

2010-01-01

To enhance the bleaching efficiency, the activator of tetra acetyl ethylene diamine (TAED) was used in conventional H2O2 bleaching. The H2O2/TAED bleaching system can accelerate the reaction rate and shorten bleaching time at relative low temperature, which can reduce the production cost. In this research, the process with hydrogen peroxide activated by TAED bleaching of Populus nigra chemi-thermo mechanical pulp was optimized. Suitable bleaching conditions were confirmed as follows: pulp con...

Stem respiration of Populus species in the third year of free-air CO2 enrichment

OpenAIRE

GIELEN, Birgit; Scarascia-Mugnozza, G.; Ceulemans, R.

2003-01-01

Carbon cycling in ecosystems, and especially in forests, is intensively studied to predict the effects of global climate change, and the role which forests may play in 'changing climate change'. One of the questions is whether the carbon balance of forests will be affected by increasing atmospheric CO2 concentrations. Regarding this question, effects of elevated [CO2 ] on woody-tissue respiration have frequently been neglected. Stem respiration of three Populus species (P. alba L. (Clone 2AS-...

Selection of Willows (Salix sp. for Biomass Production

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Davorin Kajba

2014-12-01

Full Text Available Background and Purpose: Willows compared with other species are the most suitable for biomass production in short rotations because of their very abundant growth during the first years. Nowadays, in Croatia, a large number of selected and registered willow clones are available. The main objective of the research should be to find genotypes which, with minimum nutrients, will produce the maximum quantity of biomass. Material and Methods: Clonal test of the arborescent willows include the autochthonous White Willow (Salix alba, interracial hybrids of the autochthonous White Willow and the English ‘cricket’ Willow (S. alba var. calva, interspecies hybrids (S. matsudana × S. alba, as well as multispecies hybrids of willows. Average production of dry biomass (DM∙ha-1∙a-1 per hectare was estimated in regard to the clone, survival, spacing and the number of shoots per stump. Results: The highest biomass production as well as the best adaptedness and phenotypic stability on testing site was shown by clones (‘V 374’, ‘V 461’, ‘V 578’ from 15.2 - 25.0 t∙DM∙ha-1∙a-1 originated from backcross hybrid S. matsudana × (S. matsudana × S. alba and by one S. alba clone (‘V 95’, 23.1 - 25.7 t∙DM∙ha-1∙a-1. These clones are now at the stage of registration and these results indicate significant potential for further breeding aimed at biomass production in short rotations. Conclusions: Willow clones showed high biomass production on marginal sites and dry biomass could be considerably increased with the application of intensive silvicultural and agro technical measures. No nutrition or pest control measures were applied (a practice otherwise widely used in intensive cultivation system, while weed vegetation was regulated only at the earliest age.

Influence of irrigation and fertilization on transpiration and hydraulic properties of Populus deltoides.

Energy Technology Data Exchange (ETDEWEB)

Samuelson, Lisa, J.; Stokes, Thomas, A.; Coleman, Mark, D.

2007-02-01

Summary Long-term hydraulic acclimation to resource availability was explored in 3-year-bld Populus deltoides Bartr. ex Marsh. clones by examining transpiration. leaf-specific hydraulic conductance (GL), canopy stomatal conductance (Gs) and leaf to sapwood area ratio (AL:Asi)n response to imgation (13 and 551 mm year in addition to ambient precipitation) and fertilization (0 and 120 kg N ha-' year-'). Sap flow was measured continuously over one growing season with thermal dissipation probes. Fertilization had a greater effect on growth and hydraulic properties than imgation, and fertilization effects were independent of irrigation treatment. Transpiration on a ground area basis (E) ranged between 0.3 and 1.8 mm day-', and increased 66% and 90% in response to imgation and fertilization, respectively. Increases in GL, Gs at a reference vapor pressure deficit of 1 kPa, and transpiration per unit leaf areain response to increases in resource availability were associated with reductions in AL:As and consequently a minimal change in the water potential gradient from soil to leaf. Imgation and fertilization increased leaf area index similarly, from an average 1.16 in control stands to 1.45, but sapwood area was increased from 4.0 to 6.3 m ha-' by irrigation and from 3.7 to 6.7 m2 ha-' by fertilization. The balance between leaf area and sapwood area was important in understanding long-term hydraulic acclimation to resource availability and mechanisms controlling maximum productivity in Populus deltoides.

Natural Selection and Recombination Rate Variation Shape Nucleotide Polymorphism Across the Genomes of Three Related Populus Species.

Science.gov (United States)

Wang, Jing; Street, Nathaniel R; Scofield, Douglas G; Ingvarsson, Pär K

2016-03-01

A central aim of evolutionary genomics is to identify the relative roles that various evolutionary forces have played in generating and shaping genetic variation within and among species. Here we use whole-genome resequencing data to characterize and compare genome-wide patterns of nucleotide polymorphism, site frequency spectrum, and population-scaled recombination rates in three species of Populus: Populus tremula, P. tremuloides, and P. trichocarpa. We find that P. tremuloides has the highest level of genome-wide variation, skewed allele frequencies, and population-scaled recombination rates, whereas P. trichocarpa harbors the lowest. Our findings highlight multiple lines of evidence suggesting that natural selection, due to both purifying and positive selection, has widely shaped patterns of nucleotide polymorphism at linked neutral sites in all three species. Differences in effective population sizes and rates of recombination largely explain the disparate magnitudes and signatures of linked selection that we observe among species. The present work provides the first phylogenetic comparative study on a genome-wide scale in forest trees. This information will also improve our ability to understand how various evolutionary forces have interacted to influence genome evolution among related species. Copyright © 2016 by the Genetics Society of America.

Production capacity of biomass of the floodpain community of Salix alba L. in southern Moravia

Directory of Open Access Journals (Sweden)

Diana López

2007-01-01

Full Text Available The paper deals with the study of the production capacity of biomass in the seven-year stand of Salix alba L. The communities originated in the process of primary succession in the area of the middle Nové Mlýny reservoir on a newly established island. Already since the first stages, the communities have been monitored. Results have shown that white willow behaves as an R-strategist with fast growth in youth. Moreover, the growth is supported by optimum environmental conditions (soils richly supplied with nutrients and water, long growing season. Accumulated phytomass amounted 102,7 t.ha−1 at the age of 7 years and the yield reached a mean annual increment of 15 t.ha−1.year−1. Communities of white willow rank among highly productive phytocoenoses capable of fixing considerable amounts of carbon and, at the same time fulfilling the function of habitat corridors.

Short-rotation coppices. State of the realizability, organisation and a model for the evaluation of the production and supply of rapidly growing wood from short-rotation coppices als a biofuel for biomass-fuelled heating power stations in Bavaria; Kurzumtriebsplantagen. Stand der Umsetzbarkeit, Organisation und ein Modell zur oekonomischen Bewertung von Produktion und Bereitstellung schnell wachsenden Holzes aus Kurzumtriebsplantagen als biogener Festbrennstoff fuer Biomasse(heiz)kraftwerke in Bayern

Energy Technology Data Exchange (ETDEWEB)

Paschlau, Helmut F

2011-04-07

The study examines most aspects of Short-rotation Coppice Crops (SRC), mainly from willows (Salix sp.) and poplars (Populus sp.), for energetic use in big biomass powerstations in Bavaria (southern Germany). In addition to the compilation of framework conditions concerning environmental and agrarian politics as well as legal issues, every link in the process chain of SRC will be considered - from planting to harvesting, treatment of the wood chips and Just-in-time delivery to the powerplant - followed by an evaluation of SRC in ecological terms. The basic aim of this study is to evaluate every single link with regard to organisational und economic issues, analysis of relevant markets and to develop a comprehensive calculation model for the amount of annuities of the whole process chain.

Phytoremediation capacity of poplar (Populus spp. and willow (Salix spp. clonesin relation to photosynthesis

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Pajević Slobodanka

2009-01-01

Full Text Available Good photosynthetic features and a favorable water regimes of woody plants improve their survival and remediation potential under unfavorable ecological conditions. Accordingly, we here present results of testing plant tolerance of Pb, Cd, Ni, and diesel fuel based on gas exchange parameters and WUE of four poplar and two willow clones grown in a greenhouse on soil culture. Photosynthesis and transpiration of plants grown on soils with individually applied heavy metals decreased significantly, but this was less obvious in the case of Cd treatment. A heavy metal mixture in the soil induced significant reduction in photosynthesis (by more than 50%. Diesel fuel as the only pollutant in soil caused very strong and significant inhibition of photosynthesis and transpiration of willow clones. The results indicate genotypic specificity of all investigated physiological parameters and mark poplar clones as very useful in phytoextraction technology for the bio-cleaning of chemically polluted soils.

The differential response of photosynthesis to high temperature for a boreal and temperate Populus species relates to differences in Rubisco activation and Rubisco activase properties.

Science.gov (United States)

Hozain, Moh'd I; Salvucci, Michael E; Fokar, Mohamed; Holaday, A Scott

2010-01-01

Significant inhibition of photosynthesis occurs at temperatures only a few degrees (Populus species adapted to contrasting thermal environments for determining the factors that constrain photosynthetic assimilation (A) under moderate heat stress in tree species. Consistent with its native range in temperate regions, Populus deltoides Bartr. ex Marsh. exhibited a significantly higher temperature optimum for A than did Populus balsamifera L., a boreal species. The higher A exhibited by P. deltoides at 33-40 degrees C compared to that for P. balsamifera was associated with a higher activation state of Rubisco and correlated with a higher ATPase activity of Rubisco activase. The temperature response of minimal chlorophyll a fluorescence for darkened leaves was similar for both species and was not consistent with a thylakoid lipid phase change contributing to the decline in A in the range of 30-40 degrees C. Taken together, these data support the idea that the differences in the temperature response of A for the two Populus species could be attributed to the differences in the response of Rubisco activation and ultimately to the thermal properties of Rubisco activase. That the primary sequence of Rubisco activase differed between the species, especially in regions associated with ATPase activity and Rubisco recognition, indicates that the genotypic differences in Rubisco activase might underlie the differences in the heat sensitivity of Rubisco activase and photosynthesis at moderately high temperatures.

Chloride and sodium uptake potential over an entire rotation of Populus irrigated with landfill leachate.

Science.gov (United States)

Zalesny, Jill A; Zalesny, Ronald S

2009-07-01

There is a need for information about the response of Populus genotypes to repeated application of high-salinity water and nutrient sources throughout an entire rotation. We have combined establishment biomass and uptake data with mid- and full-rotation growth data to project potential chloride (Cl-) and sodium (Na+) uptake for 2- to 11-year-old Populus in the north central United States. Our objectives were to identify potential levels of uptake as the trees developed and stages of plantation development that are conducive to variable application rates of high-salinity irrigation. The projected cumulative uptake of Cl- and Na+ during mid-rotation plantation development was stable 2 to 3 years after planting but increased steadily from year 3 to 6. Year six cumulative uptake ranged from 22 to 175 kg Cl- ha(-1) and 8 to 74 kg Na+ ha(-1), while annual uptake ranged from 8 to 54 kg Cl- ha(-1) yr(-1) and 3 to 23 kg Na+ ha(-1) yr(-1). Full-rotation uptake was greatest from 4 to 9 years (Cl-) and 4 to 8 years (Na+), with maximum levels of Cl- (32 kg ha(-1) yr(-1)) and Na+ (13 kg ha(-1) yr(-1)) occurring in year six. The relative uptake potential of Cl- and Na+ at peak accumulation (year six) was 2.7 times greater than at the end of the rotation.

Barrier to gene flow between two ecologically divergent Populus species, P. alba (white poplar) and P. tremula (European aspen): the role of ecology and life history in gene introgression.

Science.gov (United States)

Lexer, C; Fay, M F; Joseph, J A; Nica, M-S; Heinze, B

2005-04-01

The renewed interest in the use of hybrid zones for studying speciation calls for the identification and study of hybrid zones across a wide range of organisms, especially in long-lived taxa for which it is often difficult to generate interpopulation variation through controlled crosses. Here, we report on the extent and direction of introgression between two members of the "model tree" genus Populus: Populus alba (white poplar) and Populus tremula (European aspen), across a large zone of sympatry located in the Danube valley. We genotyped 93 hybrid morphotypes and samples from four parental reference populations from within and outside the zone of sympatry for a genome-wide set of 20 nuclear microsatellites and eight plastid DNA restriction site polymorphisms. Our results indicate that introgression occurs preferentially from P. tremula to P. alba via P. tremula pollen. This unidirectional pattern is facilitated by high levels of pollen vs. seed dispersal in P. tremula (pollen/seed flow = 23.9) and by great ecological opportunity in the lowland floodplain forest in proximity to P. alba seed parents, which maintains gene flow in the direction of P. alba despite smaller effective population sizes (N(e)) in this species (P. alba N(e)c. 500-550; P. tremula N(e)c. 550-700). Our results indicate that hybrid zones will be valuable tools for studying the genetic architecture of the barrier to gene flow between these two ecologically divergent Populus species.

Earthworms, arthropods and plant litter decomposition in aspen (Populus tremuloides) and lodgepole pine(Pinus contorta) forests in Colorado, USA

Science.gov (United States)

Grizelle Gonzalez; Timothy R. Seastedt; Zugeily Donato

2003-01-01

We compared the abundance and community composition of earthworms, soil macroarthropods, and litter microarthropods to test faunal effects on plant litter decomposition rates in two forests in the subalpine in Colorado, USA. Litterbags containing recently senesced litter of Populus tremuloides (aspen) and Pinus contorta (lodgepole pine) were placed in aspen and pine...

Building energetic material from novel salix leaf-like CuO and nano-Al through electrophoretic deposition

Energy Technology Data Exchange (ETDEWEB)

Yin, Yan Jun; Li, Xueming [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

2016-11-15

In this study, an energetic material was prepared by depositing nano-Al on CuO arrays via electrophoretic deposition (EPD), which offers a feasible route for nano-Al integration. The morphology and structure of the CuO arrays and Al/CuO composites were characterized by scanning electron microscopy and X-ray diffraction. The CuO arrays were homogenously salix leaf-like structure with a width of ⁓150 to 200 nm. The energy density of Al/CuO composites was approximate to 1454.5 J/g by integrating the differential scanning calorimetry (DSC) plot and the combustion performance was recorded by a high-speed camera. Moreover, the combustion flames were violent and the whole reaction process only lasted 72.2 ms, indicating that the energy of the Al/CuO nanothermite can be released effectively.

Trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus.

Science.gov (United States)

Hajek, Peter; Leuschner, Christoph; Hertel, Dietrich; Delzon, Sylvain; Schuldt, Bernhard

2014-07-01

Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plants of five demes (Populus tremula L. and Populus tremuloides Michx.) differing in growth rate, we tested the hypotheses that (i) demes differ in wood anatomical and hydraulic properties, (ii) hydraulic efficiency and safety are related to xylem anatomical traits, and (iii) aboveground productivity and hydraulic efficiency are negatively correlated to cavitation resistance. Significant deme differences existed in seven of the nine investigated branch-related anatomical and hydraulic traits but only in one of the four coarse-root-related anatomical traits; this likely is a consequence of high intra-plant variation in root morphology and the occurrence of a few 'high-conductivity roots'. Growth rate was positively related to branch hydraulic efficiency (xylem-specific conductivity) but not to cavitation resistance; this indicates that no marked trade-off exists between cavitation resistance and growth. Both branch hydraulic safety and hydraulic efficiency significantly depended on vessel size and were related to the genetic distance between the demes, while the xylem pressure causing 88% loss of hydraulic conductivity (P88 value) was more closely related to hydraulic efficiency than the commonly used P50 value. Deme-specific variation in the pit membrane structure may explain why vessel size was not directly linked to growth rate. We conclude that branch hydraulic efficiency is an important growth-influencing trait in aspen, while the assumed trade-off between productivity and hydraulic safety is weak. © The Author 2014. Published by Oxford University Press. All rights reserved

Phytoextraction with Salix viminalis in a moderately to strongly contaminated area.

Science.gov (United States)

Tőzsér, Dávid; Harangi, Sándor; Baranyai, Edina; Lakatos, Gyula; Fülöp, Zoltán; Tóthmérész, Béla; Simon, Edina

2018-02-01

We tested the suitability of Salix viminalis for phytoextraction with the analysis of selected elements in soil, root, and leaf, and by visual tree condition assessment in an area with varying levels of contamination. Bioconcentration factor (BCF) and translocation factor (TF) were used to assess the phytoextraction potential of willows. The middle part of the study area was strongly contaminated, while the northern and southern parts were moderately contaminated. We found increasing element concentrations toward deeper layers. Mean concentrations of elements in roots were similar among the three parts, while in leaves the highest concentrations were found in the strongly contaminated part of the study area. Tree condition scores were the lowest in the strongly contaminated part of the study area, which was caused by Al, Ca, K, Mg, Ni, Sr, and Zn concentration. These elements induced leaf disease and leaf feeders. The highest BCF values were found for Cu, Fe, Mn, and Zn in root, and for Cd and Zn in leaves, indicating that S. viminalis had high accumulation potential of these elements. Furthermore, TF values were high for Cd, Mn, Sr, and Zn. Our results also demonstrated that soil element composition has major influence on the condition of S. viminalis individuals. Furthermore, visual condition assessment was found to be a useful tool to assess the phytoextraction potential of trees.

Salt stress induces the formation of a novel type of 'pressure wood' in two Populus species.

Science.gov (United States)

Janz, Dennis; Lautner, Silke; Wildhagen, Henning; Behnke, Katja; Schnitzler, Jörg-Peter; Rennenberg, Heinz; Fromm, Jörg; Polle, Andrea

2012-04-01

• Salinity causes osmotic stress and limits biomass production of plants. The goal of this study was to investigate mechanisms underlying hydraulic adaptation to salinity. • Anatomical, ecophysiological and transcriptional responses to salinity were investigated in the xylem of a salt-sensitive (Populus × canescens) and a salt-tolerant species (Populus euphratica). • Moderate salt stress, which suppressed but did not abolish photosynthesis and radial growth in P. × canescens, resulted in hydraulic adaptation by increased vessel frequencies and decreased vessel lumina. Transcript abundances of a suite of genes (FLA, COB-like, BAM, XET, etc.) previously shown to be activated during tension wood formation, were collectively suppressed in developing xylem, whereas those for stress and defense-related genes increased. A subset of cell wall-related genes was also suppressed in salt-exposed P. euphratica, although this species largely excluded sodium and showed no anatomical alterations. Salt exposure influenced cell wall composition involving increases in the lignin : carbohydrate ratio in both species. • In conclusion, hydraulic stress adaptation involves cell wall modifications reciprocal to tension wood formation that result in the formation of a novel type of reaction wood in upright stems named 'pressure wood'. Our data suggest that transcriptional co-regulation of a core set of genes determines reaction wood composition. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

Identification and allelic dissection uncover roles of lncRNAs in secondary growth of Populus tomentosa.

Science.gov (United States)

Zhou, Daling; Du, Qingzhang; Chen, Jinhui; Wang, Qingshi; Zhang, Deqiang

2017-10-01

Long non-coding RNAs (lncRNAs) function in various biological processes. However, their roles in secondary growth of plants remain poorly understood. Here, 15,691 lncRNAs were identified from vascular cambium, developing xylem, and mature xylem of Populus tomentosa with high and low biomass using RNA-seq, including 1,994 lncRNAs that were differentially expressed (DE) among the six libraries. 3,569 cis-regulated and 3,297 trans-regulated protein-coding genes were predicted as potential target genes (PTGs) of the DE lncRNAs to participate in biological regulation. Then, 476 and 28 lncRNAs were identified as putative targets and endogenous target mimics (eTMs) of Populus known microRNAs (miRNAs), respectively. Genome re-sequencing of 435 individuals from a natural population of P. tomentosa found 34,015 single nucleotide polymorphisms (SNPs) within 178 lncRNA loci and 522 PTGs. Single-SNP associations analysis detected 2,993 associations with 10 growth and wood-property traits under additive and dominance model. Epistasis analysis identified 17,656 epistatic SNP pairs, providing evidence for potential regulatory interactions between lncRNAs and their PTGs. Furthermore, a reconstructed epistatic network, representing interactions of 8 lncRNAs and 15 PTGs, might enrich regulation roles of genes in the phenylpropanoid pathway. These findings may enhance our understanding of non-coding genes in plants. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Variable Nitrogen Fixation in Wild Populus.

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Sharon L Doty

Full Text Available The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

Railway transport and terminal transhipment of Short Rotation Willow Crops. Pre-study; Taagtransport och terminal-hantering av Salix. Foerstudie

Energy Technology Data Exchange (ETDEWEB)

Forsberg, Maya

2009-07-01

The overall aim of this pre-study is to contribute to an increased co-handling of biomass from forest and field at terminal and railway transport, in order to find effective transport solutions with regard to costs and environment. The aim of the pre-study is also to get an overall picture of transport of biomass on railway. The objective is to draw conclusions of use for interested parties within the agricultural sector, on what possibilities there are to handle biomass from forestry and agriculture with the same logistical infrastructure. Conclusions are drawn especially with regard to Short Rotation Willow Crops (here Salix) handled as chips or bundles, but also briefly for other energy crops suitable for combustion. Furthermore, the study draws conclusions on how to design effective terminals and related costs. The pre-study is intended as a planning material for a more in-depth study of a mobile terminal solution, with active participation from interested players in the agricultural sector. When considering railway transport and terminal transhipment of large volumes of biomass, there is a clear economical benefit in designing large terminals and making investments in effective handling equipment, in order to get a high use of equipment and a high storage turnover. A more simple and temporary terminal solution may be suitable for smaller flows of biomass, such as agricultural fuels, which need to be collected in different areas according to availability. An intermodal solution, i.e. which involves the transportation of freight in the same type of carrier (a container for example) when changing modes of transportation, is suitable for this purpose. The solution should also build on standardised equipment, involve low terminal investments and flexible and temporary transhipment in different areas near the location of the biomass. For railway transport, the same handling equipment may be used for wood chips and Salix chips, i.e. standardised container systems

Zinc accumulation potential and toxicity threshold determined for a metal-accumulating Populus canescens clone in a dose-response study

Energy Technology Data Exchange (ETDEWEB)

Langer, Ingrid [Institute of Soil Science, University of Natural Resources and Applied Life Sciences, Peter Jordan-Strasse 82, A-1190 Vienna (Austria); Krpata, Doris [Institute of Microbiology, Innsbruck University, Technikerstrasse 25, A-6020 Innsbruck (Austria); Fitz, Walter J.; Wenzel, Walter W. [Institute of Soil Science, University of Natural Resources and Applied Life Sciences, Peter Jordan-Strasse 82, A-1190 Vienna (Austria); Schweiger, Peter F., E-mail: peter.schweiger@boku.ac.a [Institute of Soil Science, University of Natural Resources and Applied Life Sciences, Peter Jordan-Strasse 82, A-1190 Vienna (Austria)

2009-10-15

The effect of increasing soil Zn concentrations on growth and Zn tissue concentrations of a metal-accumulating aspen clone was examined in a dose-response study. Plants were grown in a soil with a low native Zn content which was spiked with Zn salt solutions and subsequently aged. Plant growth was not affected by NH{sub 4}NO{sub 3}-extractable soil Zn concentrations up to 60 mug Zn g{sup -1} soil, but it was completely inhibited at extractable concentrations above 90 mug Zn g{sup -1} soil. From these data an effective concentration of 68.5 mug extractable Zn g{sup -1} soil was calculated at which plant growth was reduced by 50%. The obtained information on toxicity threshold concentrations, and the relation between plant Zn accumulation and extractable soil Zn concentrations may be used to assess the suitability of the investigated Populus canescens clone for various phytoremediation strategies. The potential risk of metal transfer into food webs associated with P. canescens stands on Zn-polluted sites may also be estimated. - Quantitative information about the concentration-dependent Zn accumulation of Populus canescens contributes to assess its suitability for phytoremediation.

A study of polymerization of aspen (Populus) wood lipophilic extractives by SEC and Py-GC/MS

CSIR Research Space (South Africa)

Sithole, Bruce

2013-03-01

Full Text Available ) Orig inal manuscript received 13 June 2012, revision accepted 31 October 2012 Vol 66 No 1 January - March 2013 1 PEER REVIEWED A study of polymerization of aspen (Populus) wood lipophilic extractives by SEC and Py-GC/MS BRUCE SITHOLE1*, LUC... of polymerized wood resin that will be difficult to remove if present in pulp and paper products. On the other hand, these problems may be minor compared to using unseasoned wood. KEYWORDS: Aspen, extractives, polymerization, size exclusion chromatography, Py...

Epigenomics of Development in Populus

Energy Technology Data Exchange (ETDEWEB)

Strauss, Steve; Freitag, Michael; Mockler, Todd

2013-01-10

We conducted research to determine the role of epigenetic modifications during tree development using poplar (Populus trichocarpa), a model woody feedstock species. Using methylated DNA immunoprecipitation (MeDIP) or chromatin immunoprecipitation (ChIP), followed by high-throughput sequencing, we are analyzed DNA and histone methylation patterns in the P. trichocarpa genome in relation to four biological processes: bud dormancy and release, mature organ maintenance, in vitro organogenesis, and methylation suppression. Our project is now completed. We have 1) produced 22 transgenic events for a gene involved in DNA methylation suppression and studied its phenotypic consequences; 2) completed sequencing of methylated DNA from eleven target tissues in wildtype P. trichocarpa; 3) updated our customized poplar genome browser using the open-source software tools (2.13) and (V2.2) of the P. trichocarpa genome; 4) produced summary data for genome methylation in P. trichocarpa, including distribution of methylation across chromosomes and in and around genes; 5) employed bioinformatic and statistical methods to analyze differences in methylation patterns among tissue types; and 6) used bisulfite sequencing of selected target genes to confirm bioinformatics and sequencing results, and gain a higher-resolution view of methylation at selected genes 7) compared methylation patterns to expression using available microarray data. Our main findings of biological significance are the identification of extensive regions of the genome that display developmental variation in DNA methylation; highly distinctive gene-associated methylation profiles in reproductive tissues, particularly male catkins; a strong whole genome/all tissue inverse association of methylation at gene bodies and promoters with gene expression; a lack of evidence that tissue specificity of gene expression is associated with gene methylation; and evidence that genome methylation is a significant impediment to tissue

Genome-wide analysis and heavy metal-induced expression profiling of the HMA gene family in Populus trichocarpa

Directory of Open Access Journals (Sweden)

Dandan eLi

2015-12-01

Full Text Available The heavy metal ATPase (HMA family plays an important role in transition metal transport in plants. However, this gene family has not been extensively studied in Populus trichocarpa. We identified 17 HMA genes in P. trichocarpa (PtHMAs, of which PtHMA1–PtHMA4 belonged to the zinc (Zn/cobalt (Co/cadmium (Cd/lead (Pb subgroup, and PtHMA5–PtHMA8 were members of the copper (Cu/silver (Ag subgroup. Most of the genes were localized to chromosomes I and III. Gene structure, gene chromosomal location, and synteny analyses of PtHMAs indicated that tandem and segmental duplications likely contributed to the expansion and evolution of the PtHMAs. Most of the HMA genes contained abiotic stress-related cis-elements. Tissue-specific expression of PtHMA genes showed that PtHMA1 and PtHMA4 had relatively high expression levels in the leaves, whereas Cu/Ag subgroup (PtHMA5.1- PtHMA8 genes were upregulated in the roots. High concentrations of Cu, Ag, Zn, Cd, Co, Pb and Mn differentially regulated the expression of PtHMAs in various tissues. The preliminary results of the present study generated basic information on the HMA family of Populus that may serve as foundation for future functional studies.

Genome-wide Identification of WRKY Genes in the Desert Poplar Populus euphratica and Adaptive Evolution of the Genes in Response to Salt Stress.

Science.gov (United States)

Ma, Jianchao; Lu, Jing; Xu, Jianmei; Duan, Bingbing; He, Xiaodong; Liu, Jianquan

2015-01-01

WRKY transcription factors play important roles in plant development and responses to various stresses in plants. However, little is known about the evolution of the WRKY genes in the desert poplar species Populus euphratica, which is highly tolerant of salt stress. In this study, we identified 107 PeWRKY genes from the P. euphratica genome and examined their evolutionary relationships with the WRKY genes of the salt-sensitive congener Populus trichocarpa. Ten PeWRKY genes are specific to P. euphratica, and five of these showed altered expression under salt stress. Furthermore, we found that two pairs of orthologs between the two species showed evidence of positive evolution, with dN/dS ratios>1 (nonsynonymous/synonymous substitutions), and both of them altered their expression in response to salinity stress. These findings suggested that both the development of new genes and positive evolution in some orthologs of the WRKY gene family may have played an important role in the acquisition of high salt tolerance by P. euphratica.

The use of the white poplar (Populus alba L.) biomass as fuel

Institute of Scientific and Technical Information of China (English)

Tatiana Griu; Aurel Lunguleasa

2016-01-01

We determined the calorific value of white poplar (Populus alba L.) woody biomass to use it as fire-wood. The value of 19.133 MJ kg-1 obtained experimen-tally shows that the white poplar can be quite successfully used as firewood. Being of a lower quality in comparison with usual beech firewood, the white poplar has similar calorific value. The white poplar has a calorific density of 30.7%lower than that of current firewood. That is why the price of this firewood from white poplar is lower accord-ingly. Also, the prognosis of calorific value on the basis of the main chemical elements, being very close to the experimental value (?2.6%), indicates an appropriate value can be achieved to be used for investigation with the chemical element analysis.

A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis

Energy Technology Data Exchange (ETDEWEB)

Dong, Yan [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Liaoning Forestry Vocational-Technical College, Shenyang 110101 (China); Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Xia, Xinli, E-mail: xiaxl@bjfu.edu.cn [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China); Yin, Weilun, E-mail: yinwl@bjfu.edu.cn [College of Biological Sciences and Technology, National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083 (China)

2014-07-18

Highlights: • PebHLH35 is firstly cloned from Populus euphratica and characterized its functions. • PebHLH35 is important for earlier seedling establishment and vegetative growth. • PebHLH35 enhances tolerance to drought by regulating growth. • PebHLH35 enhances tolerance to drought by regulating stomatal development. • PebHLH35 enhances tolerance to drought by regulating photosynthesis and transpiration. - Abstract: Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth.

A novel bHLH transcription factor PebHLH35 from Populus euphratica confers drought tolerance through regulating stomatal development, photosynthesis and growth in Arabidopsis

International Nuclear Information System (INIS)

Dong, Yan; Wang, Congpeng; Han, Xiao; Tang, Sha; Liu, Sha; Xia, Xinli; Yin, Weilun

2014-01-01

Highlights: • PebHLH35 is firstly cloned from Populus euphratica and characterized its functions. • PebHLH35 is important for earlier seedling establishment and vegetative growth. • PebHLH35 enhances tolerance to drought by regulating growth. • PebHLH35 enhances tolerance to drought by regulating stomatal development. • PebHLH35 enhances tolerance to drought by regulating photosynthesis and transpiration. - Abstract: Plant basic helix-loop-helix (bHLH) transcription factors (TFs) are involved in a variety of physiological processes including the regulation of plant responses to various abiotic stresses. However, few drought-responsive bHLH family members in Populus have been reported. In this study, a novel bHLH gene (PebHLH35) was cloned from Populus euphratica. Expression analysis in P. euphratica revealed that PebHLH35 was induced by drought and abscisic acid. Subcellular localization studies using a PebHLH35-GFP fusion showed that the protein was localized to the nucleus. Ectopic overexpression of PebHLH35 in Arabidopsis resulted in a longer primary root, more leaves, and a greater leaf area under well-watered conditions compared with vector control plants. Notably, PebHLH35 overexpression lines showed enhanced tolerance to water-deficit stress. This finding was supported by anatomical and physiological analyses, which revealed a reduced stomatal density, stomatal aperture, transpiration rate, and water loss, and a higher chlorophyll content and photosynthetic rate. Our results suggest that PebHLH35 functions as a positive regulator of drought stress responses by regulating stomatal density, stomatal aperture, photosynthesis and growth

Variation of leaf margin serration in Populus nigra of industrial dumps

Directory of Open Access Journals (Sweden)

Yu. A. Shtirs

2017-07-01

Full Text Available The variability of leaf margin serration of Populus nigra L. in conditions of industrial dumps (coal mines dumps and overburden dumps and city park is estimated. The value of this indicator is in the range from 1.25 to 1.76 and significantly increases along the gradient: coal mines dumps – overburden dumps – city park. From the number of selected gradations of P. nigra leaf blades, the gradation with values of 1.45-1.55 is most pronounced according to the analyzed index for industrial dumps, for the park – with the values of 1.55-1.65. The degree of serration of edge leaf blade is characterized by low values of variation – coefficient of variation is less than 10.0%. We registered the significant positive correlation between the average values of leaf margin serration and the length of P. nigra leaf blade.

Natural hybridization between Populus nigra L. and P. x canadensis Moench. Hybrid offspring competes for niches along the Rhine river in the Netherlands

NARCIS (Netherlands)

Smulders, M.J.M.; Beringen, R.; Volosyanchuk, R.; Vanden Broeck, A.; Schoot, van der J.; Arens, P.F.P.; Vosman, B.

2008-01-01

Black poplar (Populus nigra L.) is a major species for European riparian forests but its abundance has decreased over the decades due to human influences. For restoration of floodplain woodlands, the remaining black poplar stands may act as source population. A potential problem is that P. nigra and

Incorporating climate change and exotic species into forecasts of riparian forest distribution.

Directory of Open Access Journals (Sweden)

Dana H Ikeda

Full Text Available We examined the impact climate change (CC will have on the availability of climatically suitable habitat for three native and one exotic riparian species. Due to its increasing prevalence in arid regions throughout the western US, we predicted that an exotic species, Tamarix, would have the greatest increase in suitable habitat relative to native counterparts under CC. We used an ecological niche model to predict range shifts of Populus fremontii, Salix gooddingii, Salix exigua and Tamarix, from present day to 2080s, under five general circulation models and one climate change scenario (A1B. Four major findings emerged. 1 Contrary to our original hypothesis, P. fremontii is projected to have the greatest increase in suitable habitat under CC, followed closely by Tamarix. 2 Of the native species, S. gooddingii and S. exigua showed the greatest loss in predicted suitable habitat due to CC. 3 Nearly 80 percent of future P. fremontii and Salix habitat is predicted to be affected by either CC or Tamarix by the 2080s. 4 By the 2080s, 20 percent of S. gooddingii habitat is projected to be affected by both Tamarix and CC concurrently, followed by S. exigua (19 percent and P. fremontii (13 percent. In summary, while climate change alone will negatively impact both native willow species, Tamarix is likely to affect a larger portion of all three native species' distributions. We discuss these and other results in the context of prioritizing restoration and conservation efforts to optimize future productivity and biodiversity. As we are accounting for only direct effects of CC and Tamarix on native habitat, we present a possible hierarchy of effects- from the direct to the indirect- and discuss the potential for the indirect to outweigh the direct effects. Our results highlight the need to account for simultaneous challenges in the face of CC.

A systems biology, whole-genome association analysis of the molecular regulation of biomass growth and composition in Populus deltoides

Energy Technology Data Exchange (ETDEWEB)

Kirst, Matias [Univ. of Florida, Gainesville, FL (United States)

2014-04-14

Poplars trees are well suited for biofuel production due to their fast growing habit, favorable wood composition and adaptation to a broad range of environments. The availability of a reference genome sequence, ease of vegetative propagation and availability of transformation methods also make poplar an ideal model for the study of wood formation and biomass growth in woody, perennial plants. The objective of this project was to conduct a genome-wide association genetics study to identify genes that regulate bioenergy traits in Populus deltoides (eastern cottonwood). Populus deltoides is a genetically diverse keystone forest species in North America and an important short rotation woody crop for the bioenergy industry. We searched for associations between eight growth and wood composition traits and common and low-frequency single-nucleotide polymorphisms (SNPs) detected by targeted resequencing of 18,153 genes in a population of 391 unrelated individuals. To increase power to detect associations with low-frequency variants, multiple-marker association tests were used in combination with single-marker association tests. Significant associations were discovered for all phenotypes and are indicative that low-frequency polymorphisms contribute to phenotypic variance of several bioenergy traits. These polymorphism are critical tools for the development of specialized plant feedstocks for bioenergy.

A systems biology, whole-genome association analysis of the molecular regulation of biomass growth and composition in Populus deltoides

Energy Technology Data Exchange (ETDEWEB)

Kirst, Matias [Univ. of Florida, Gainesville, FL (United States)

2015-04-15

Poplars trees are well suited for biofuel production due to their fast growing habit, favorable wood composition and adaptation to a broad range of environments. The availability of a reference genome sequence, ease of vegetative propagation and availability of transformation methods also make poplar an ideal model for the study of wood formation and biomass growth in woody, perennial plants. The objective of this project was to conduct a genome-wide association genetics study to identify genes that regulate bioenergy traits in Populus deltoides (eastern cottonwood). Populus deltoides is a genetically diverse keystone forest species in North America and an important short rotation woody crop for the bioenergy industry. We searched for associations between eight growth and wood composition traits and common and low-frequency single-nucleotide polymorphisms (SNPs) detected by targeted resequencing of 18,153 genes in a population of 391 unrelated individuals. To increase power to detect associations with low-frequency variants, multiple-marker association tests were used in combination with single-marker association tests. Significant associations were discovered for all phenotypes and are indicative that low-frequency polymorphisms contribute to phenotypic variance of several bioenergy traits. These polymorphism are critical tools for the development of specialized plant feedstocks for bioenergy.

Developmental and environmental regulation of Aquaporin gene expression across Populus species: divergence or redundancy?

Science.gov (United States)

Cohen, David; Bogeat-Triboulot, Marie-Béatrice; Vialet-Chabrand, Silvère; Merret, Rémy; Courty, Pierre-Emmanuel; Moretti, Sébastien; Bizet, François; Guilliot, Agnès; Hummel, Irène

2013-01-01

Aquaporins (AQPs) are membrane channels belonging to the major intrinsic proteins family and are known for their ability to facilitate water movement. While in Populus trichocarpa, AQP proteins form a large family encompassing fifty-five genes, most of the experimental work focused on a few genes or subfamilies. The current work was undertaken to develop a comprehensive picture of the whole AQP gene family in Populus species by delineating gene expression domain and distinguishing responsiveness to developmental and environmental cues. Since duplication events amplified the poplar AQP family, we addressed the question of expression redundancy between gene duplicates. On these purposes, we carried a meta-analysis of all publicly available Affymetrix experiments. Our in-silico strategy controlled for previously identified biases in cross-species transcriptomics, a necessary step for any comparative transcriptomics based on multispecies design chips. Three poplar AQPs were not supported by any expression data, even in a large collection of situations (abiotic and biotic constraints, temporal oscillations and mutants). The expression of 11 AQPs was never or poorly regulated whatever the wideness of their expression domain and their expression level. Our work highlighted that PtTIP1;4 was the most responsive gene of the AQP family. A high functional divergence between gene duplicates was detected across species and in response to tested cues, except for the root-expressed PtTIP2;3/PtTIP2;4 pair exhibiting 80% convergent responses. Our meta-analysis assessed key features of aquaporin expression which had remained hidden in single experiments, such as expression wideness, response specificity and genotype and environment interactions. By consolidating expression profiles using independent experimental series, we showed that the large expansion of AQP family in poplar was accompanied with a strong divergence of gene expression, even if some cases of functional redundancy

Developmental and environmental regulation of Aquaporin gene expression across Populus species: divergence or redundancy?

Directory of Open Access Journals (Sweden)

David Cohen

Full Text Available Aquaporins (AQPs are membrane channels belonging to the major intrinsic proteins family and are known for their ability to facilitate water movement. While in Populus trichocarpa, AQP proteins form a large family encompassing fifty-five genes, most of the experimental work focused on a few genes or subfamilies. The current work was undertaken to develop a comprehensive picture of the whole AQP gene family in Populus species by delineating gene expression domain and distinguishing responsiveness to developmental and environmental cues. Since duplication events amplified the poplar AQP family, we addressed the question of expression redundancy between gene duplicates. On these purposes, we carried a meta-analysis of all publicly available Affymetrix experiments. Our in-silico strategy controlled for previously identified biases in cross-species transcriptomics, a necessary step for any comparative transcriptomics based on multispecies design chips. Three poplar AQPs were not supported by any expression data, even in a large collection of situations (abiotic and biotic constraints, temporal oscillations and mutants. The expression of 11 AQPs was never or poorly regulated whatever the wideness of their expression domain and their expression level. Our work highlighted that PtTIP1;4 was the most responsive gene of the AQP family. A high functional divergence between gene duplicates was detected across species and in response to tested cues, except for the root-expressed PtTIP2;3/PtTIP2;4 pair exhibiting 80% convergent responses. Our meta-analysis assessed key features of aquaporin expression which had remained hidden in single experiments, such as expression wideness, response specificity and genotype and environment interactions. By consolidating expression profiles using independent experimental series, we showed that the large expansion of AQP family in poplar was accompanied with a strong divergence of gene expression, even if some cases of

Stem wood properties of Populus tremuloides, Betula papyrifera and Acer saccharum saplings after three years of treatments to elevated carbon dioxide and ozone

Science.gov (United States)

Seija Kaakinen; Katri Kostiainen; Fredrik Ek; Pekka Saranpaa; Mark E. Kubiske; Jaak Sober; David F. Karnosky; Elina Vapaavuori

2004-01-01

The aim of this study was to examine the effects of elevated carbon dioxide [CO2] and ozone [O3] and their interaction on wood chemistry and anatomy of five clones of 3-year-old trembling aspen (Populus tremuloides Michx.). Wood chemistry was studied also on paper birch (Betula papyrifera...

Structure and diversity of ground mesofauna inUlmus and Populus consortia in the industrial areas of mining and smelting complex of krivyi rig basin

Directory of Open Access Journals (Sweden)

V. V. Kachinskaya

2010-05-01

Full Text Available The structure and biological diversity of ground mesofauna on a consortium level of organisation of ecosystems are considered. Indicators of structural organisation and biodiversity of ground mesofauna were analised in Ulmus and Populus consortia in the conditions of industrial territories of mining and smelting complex of Krivyi Rig Basin. It is established that taxonomical structure of ground mesofauna is characterised by insignificant number and quantity of taxonomical groups. Prevalence of hortobionts and herpetobionts in morpho-ecological structure of the community testifies to their attachment to consortium’s determinants and influence of steppe climate on its structure. Dominance of phytophages and polyphages in trophic structure is caused by a combination of consortium determinants specificity and «a zone source» of the fauna formations. The structural organisation of ground mesofauna in consortia of Ulmus and Populus in the conditions of industrial sites is characterised by simplified taxonomical structure with low biodiversity at all levels.

Climate, migration, and the local food security context: Introducing Terra Populus

Science.gov (United States)

Schlak, Allison M.; Kugler, Tracy A.

2016-01-01

Studies investigating the connection between environmental factors and migration are difficult to execute because they require the integration of microdata and spatial information. In this article, we introduce the novel, publically available data extraction system Terra Populus (TerraPop), which was designed to facilitate population-environment studies. We showcase the use of TerraPop by exploring variations in the climate-migration association in Burkina Faso and Senegal based on differences in the local food security context. Food security was approximated using anthropometric indicators of child stunting and wasting derived from Demographic and Health Surveys (DHS) and linked to the TerraPop extract of climate and migration information. We find that an increase in heat waves was associated with a decrease in international migration from Burkina Faso, while excessive precipitation increased international moves from Senegal. Significant interactions reveal that the adverse effects of heat waves and droughts are strongly amplified in highly food insecure Senegalese departments. PMID:27974863

Tamarisk control, water salvage, and wildlife habitat restoration along rivers in the western United States

Science.gov (United States)

Shafroth, Patrick B.

2006-01-01

In the latter part of the 19th century, species of the nonnative shrub tamarisk (also called saltcedar; for example, Tamarix ramosissima, T. chinensis) were introduced to the United States for use as ornamental plants for erosion control. By 1877, some naturalized populations had become established, and by the 1960s, tamarisk was present along most rivers in the semi-arid and arid parts of the West and was quite abundant along downstream ranches of the major southwest rivers such as the Colorado, Rio Grande, Gila, and Pecos. The principal period of tamarisk invasion coincided with changing physical conditions along western rivers associated with the construction and operation of dams. In many cases, these altered physical conditions appear to have been more favorable for tamarisk than native riparian competitors like cottonwoods and willows (Populus and Salix; Glenn and Nagler, 2005).

Exploiting the transcriptome of Euphrates Poplar, Populus euphratica (Salicaceae to develop and characterize new EST-SSR markers and construct an EST-SSR database.

Directory of Open Access Journals (Sweden)

Fang K Du

Full Text Available BACKGROUND: Microsatellite markers or Simple Sequence Repeats (SSRs are the most popular markers in population/conservation genetics. However, the development of novel microsatellite markers has been impeded by high costs, a lack of available sequence data and technical difficulties. New species-specific microsatellite markers were required to investigate the evolutionary history of the Euphratica tree, Populus euphratica, the only tree species found in the desert regions of Western China and adjacent Central Asian countries. METHODOLOGY/PRINCIPAL FINDINGS: A total of 94,090 non-redundant Expressed Sequence Tags (ESTs from P. euphratica comprising around 63 Mb of sequence data were searched for SSRs. 4,202 SSRs were found in 3,839 ESTs, with 311 ESTs containing multiple SSRs. The most common motif types were trinucleotides (37% and hexanucleotides (33% repeats. We developed primer pairs for all of the identified EST-SSRs (eSSRs and selected 673 of these pairs at random for further validation. 575 pairs (85% gave successful amplification, of which, 464 (80.7% were polymorphic in six to 24 individuals from natural populations across Northern China. We also tested the transferability of the polymorphic eSSRs to nine other Populus species. In addition, to facilitate the use of these new eSSR markers by other researchers, we mapped them onto Populus trichocarpa scaffolds in silico and compiled our data into a web-based database (http://202.205.131.253:8080/poplar/resources/static_page/index.html. CONCLUSIONS: The large set of validated eSSRs identified in this work will have many potential applications in studies on P. euphratica and other poplar species, in fields such as population genetics, comparative genomics, linkage mapping, QTL, and marker-assisted breeding. Their use will be facilitated by their incorporation into a user-friendly web-based database.

Analysis of a Farquhar-von Caemmerer-Berry leaf-level photosynthetic rate model for Populus tremuloides in the context of modeling and measurement limitations

Science.gov (United States)

K.E. Lenz; G.E. Host; K. Roskoski; A. Noormets; A. Sober; D.F. Karnosky

2010-01-01

The balance of mechanistic detail with mathematical simplicity contributes to the broad use of the Farquhar, von Caemmerer and Berry (FvCB) photosynthetic rate model. Here the FvCB model was coupled with a stomatal conductance model to form an [A,gs] model, and parameterized for mature Populus tremuloides leaves under varying CO2...

Analysis of a Farquhar-von Caemmerer-Berry leaf-level photosynthetic rate model for Populus tremuloides in the context of modeling and measurement limitations

International Nuclear Information System (INIS)

Lenz, Kathryn E.; Host, George E.; Roskoski, Kyle; Noormets, Asko; Sober, Anu; Karnosky, David F.

2010-01-01

The balance of mechanistic detail with mathematical simplicity contributes to the broad use of the Farquhar, von Caemmerer and Berry (FvCB) photosynthetic rate model. Here the FvCB model was coupled with a stomatal conductance model to form an [A,g s ] model, and parameterized for mature Populus tremuloides leaves under varying CO 2 and temperature levels. Data were selected to be within typical forest light, CO 2 and temperature ranges, reducing artifacts associated with data collected at extreme values. The error between model-predicted photosynthetic rate (A) and A data was measured in three ways and found to be up to three times greater for each of two independent data sets than for a base-line evaluation using parameterization data. The evaluation methods used here apply to comparisons of model validation results among data sets varying in number and distribution of data, as well as to performance comparisons of [A,g s ] models differing in internal-process components. - A photosynthetic rate model is parameterized for Populus tremuloides and evaluated based on its ability to predict dependent as well as independent data.

Ascus dysgenesis in hybrid crosses of Neurospora and Sordaria (Sordariaceae).

Science.gov (United States)

Kasbekar, Durgadas P

2017-07-01

When two lineages derived from a common ancestor become reproductively isolated (e.g. Neurospora crassa and N. tetrasperma), genes that have undergone mutation and adaptive evolution in one lineage can potentially become dysfunctional when transferred into the other, since other genes have undergone mutation and evolution in the second lineage, and the derived alleles were never 'tested' together before hybrid formation. Bateson (1909), Dobzhansky (1936), and Muller (1942) recognized that incompatibility between the derived alleles could potentially make the hybrid lethal, sterile, or display some other detriment. Alternatively, the detrimental effects seen in crosses with the hybrids may result from the silencing of ascus-development genes by meiotic silencing by unpaired DNA (MSUD). Aberrant transcripts from genes improperly paired in meiosis are processed into single-stranded MSUD-associated small interfering RNA (masiRNA), which is used to degrade complementary mRNA. Recently, backcrosses of N. crassa / N. tetrasperma hybrid translocation strains with wild-type N. tetrasperma were found to elicit novel ascus dysgenesis phenotypes. One was a transmission ratio distortion that apparently disfavoured the homokaryotic ascospores formed following alternate segregation. Another was the production of heterokaryotic ascospores in eight-spored asci. Lewis (1969) also had reported sighting rare eight-spored asci with heterokaryotic ascospores in interspecific crosses in Sordaria, a related genus. Ordinarily, in both Neurospora and Sordaria, the ascospores are partitioned at the eight-nucleus stage, and ascospores in eight-spored asci are initially uninucleate. Evidently, in hybrid crosses of the family Sordariaceae, ascospore partitioning can be delayed until after one or more mitoses following the postmeiotic mitosis.

Populus species from diverse habitats maintain high night-time conductance under drought.

Science.gov (United States)

Cirelli, Damián; Equiza, María Alejandra; Lieffers, Victor James; Tyree, Melvin Thomas

2016-02-01

We investigated the interspecific variability in nocturnal whole-plant stomatal conductance under well-watered and drought conditions in seedlings of four species of Populus from habitats characterized by abundant water supply (mesic and riparian) or from drier upland sites. The study was carried out to determine whether (i) nocturnal conductance varies across different species of Populus according to their natural habitat, (ii) nocturnal conductance is affected by water stress similarly to daytime conductance based on species habitat and (iii) differences in conductance among species could be explained partly by differences in stomatal traits. We measured whole-plant transpiration and conductance (G) of greenhouse-grown seedlings using an automated high-resolution gravimetric technique. No relationship was found between habitat preference and daytime G (GD), but night-time G (GN) was on average 1.5 times higher in riparian and mesic species (P. deltoides Bartr. ex Marsh. and P. trichocarpa Torr. & Gray) than in those from drier environments (P. tremuloides Michx. and P. × petrowskyana Schr.). GN was not significantly reduced under drought in riparian species. Upland species restricted GN significantly in response to drought, but it was still at least one order of magnitude greater that the cuticular conductance until leaf death was imminent. Under both well-watered and drought conditions, GN declined with increasing vapour pressure deficit (D). Also, a small increase in GN towards the end of the night period was observed in P. deltoides and P. × petrowskyana, suggesting the involvement of endogenous regulation. The anatomical analyses indicated a positive correlation between G and variable stomatal pore index among species and revealed that stomata are not likely to be leaky but instead seem capable of complete occlusion, which raises the question of the possible physiological role of the significant GN observed under drought. Further comparisons among

Assessment of abandoned agricultural land resource for bio-energy production in Estonia

Energy Technology Data Exchange (ETDEWEB)

Kukk, Liia; Astover, Alar; Roostalu, Hugo; Suuster, Elsa; Noormets, Merrit; Sepp, Kalev (Estonian Univ. of Life Sciences, Inst. of Agricultural and Environmental Sciences, Tartu (Estonia)); Muiste, Peeter (Estonian Univ. of Life Sciences, Inst. of Forestry and Rural Engineering, Tartu (Estonia))

2010-03-15

The current study locates and quantifies abandoned agricultural areas using the Geographic Information System (GIS) and evaluates the suitability of abandoned fields for bio-energy production in Tartumaa (Tartu County) in Estonia. Soils of abandoned areas are generally of low quality and thereby limited suitability for crop production; as a result soil-crop suitability analyses could form the basis of knowledge-based bio-energy planning. The study estimated suitable areas for bio-energy production using willow (Salix sp), grey alder [Alnus incana (L.) Moench], hybrid aspen (Populus tremuloides Michx.Populus tremula L.), reed canary grass (Phalaris arundinacea L.), and Caucasian goat's rue (Galega orientalis Lam.) in separate plantations. A combined land-use strategy is also presented as these crops are partially suitable to the same areas. Reed canary grass and grey alder have the highest energy potentials and each would re-use more than 80% of the available abandoned agricultural land. Energy grasses and short-rotation forestry in combined land-use strategy represents the opportunity of covering approximately a quarter of county's annual energy demand. The study estimates only agronomic potential, so further bio-energy analysis should take into account technical and economic limitations. Developed framework supports knowledge-based decision-making processes from field to regional scale to achieve sustainable bio-energy production

Commentary

Indian Academy of Sciences (India)

PRAKASH

all known Neurospora mutants, chromosome rearrangements, wild and .... Robert Metzenberg and colleagues, including David's associate N B Raju, ... tetrasperma was Dodge's favorite species and he tried (without success) to get his visitors interested in ... They are survived by their daughter Susan and her husband John.

Xylem anatomy correlates with gas exchange, water-use efficiency and growth performance under contrasting water regimes: evidence from Populus deltoides x Populus nigra hybrids.

Science.gov (United States)

Fichot, Régis; Laurans, Françoise; Monclus, Romain; Moreau, Alain; Pilate, Gilles; Brignolas, Franck

2009-12-01

Six Populus deltoides Bartr. ex Marsh. x P. nigra L. genotypes were selected to investigate whether stem xylem anatomy correlated with gas exchange rates, water-use efficiency (WUE) and growth performance. Clonal copies of the genotypes were grown in a two-plot common garden test under contrasting water regimes, with one plot maintained irrigated and the other one subjected to moderate summer water deficit. The six genotypes displayed a large range of xylem anatomy, mean vessel and fibre diameter varying from about 40 to 60 microm and from 7.5 to 10.5 microm, respectively. Decreased water availability resulted in a reduced cell size and an important rise in vessel density, but the extent of xylem plasticity was both genotype and trait dependent. Vessel diameter and theoretical xylem-specific hydraulic conductivity correlated positively with stomatal conductance, carbon isotope discrimination and growth performance-related traits and negatively with intrinsic WUE, especially under water deficit conditions. Vessel diameter and vessel density measured under water deficit conditions correlated with the relative losses in biomass production in response to water deprivation; this resulted from the fact that a more plastic xylem structure was generally accompanied by a larger loss in biomass production.

[Soil moisture dynamics and water balance of Salix psammophila shrubs in south edge of Mu Us Sandy Land].

Science.gov (United States)

An, Hui; An, Yu

2011-09-01

Taking the artificial sand-fixing Salix psammophila shrubs with different plant density (0.2, 0.6, and 0.8 plants x m(-2)) in Mu Us Sandy Land as test objects, this paper studied the soil moisture dynamics and evapotranspiration during growth season. There existed obvious differences in the soil moisture dynamics and evapotranspiration among the shrubs. The soil moisture content changed in single-hump-shape with the increase of plant density, and in "S" shape during growth season, being closely correlated with precipitation. The evapotranspiration was the highest (114.5 mm) in the shrubs with a density 0.8 plants x m(-1), accounting for 90.8% of the total precipitation during growth season, and the lowest (109.7 mm) in the shrubs with a density 0.6 plants x m(-2) Based on the soil moisture dynamics and water balance characteristics, the appropriate planting density of S. psammophila shrubs in Mu Us Sandy Land could be 0.6 plants x m(-2).

Can liming change root anatomy, biomass allocation and trace element distribution among plant parts of Salix × smithiana in trace element-polluted soils?

Science.gov (United States)

Vondráčková, Stanislava; Tlustoš, Pavel; Száková, Jiřina

2017-08-01

Willows (Salix spp.) are considered to be effective for the phytoremediation of trace elements from contaminated soils, but their efficiency is limited in heavily polluted soils because of poor growth. Liming can be a desirable measure to decrease the plant availability of elements, resulting in improved plant development. Notably, large root area and maximum soil penetration are basic parameters that improve the efficiency of phytoremediation. The impact of soil chemical properties on willow root anatomy and the distribution of trace elements below-ground have rarely been studied. The effect of liming on root parameters, biomass allocation and trace element distribution in non-harvestable (coarse roots, fine roots, stumps) and harvestable plant parts (twigs and leaves) of Salix × smithiana was assessed at the end of a 4-year pot experiment with two trace element-polluted soils that differed in terms of soil pH. Stump biomass predominated in weakly acidic soil. In neutral soil, the majority of biomass was located in fine roots and stumps; the difference from other plant parts was minor. Trace elements were the most concentrated in fine roots. Translocation to above-ground biomass increased as follows: Pb roots roots). Lime application decreased the concentrations of mobile Cd and Zn and related levels in plants, improved biomass production and root parameters and increased the removal of all trace elements in weakly acidic soil. None or minimum differences in the monitored parameters were recorded for dolomite treatments in both soils. The dose and source of liming had crucial effects on root anatomy. Growing willows in limed trace element-polluted soils is a suitable measure for combination of two remediation strategies, i.e. phytoextraction of Cd and Zn and assisted phytostabilization of As and Pb.

Effects of hybridization and evolutionary constraints on secondary metabolites: the genetic architecture of phenylpropanoids in European populus species.

Science.gov (United States)

Caseys, Celine; Stritt, Christoph; Glauser, Gaetan; Blanchard, Thierry; Lexer, Christian

2015-01-01

The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar) and P. tremula (European aspen) and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS). We detected 41 quantitative trait loci (QTL) for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the 'model forest tree' Populus.

Effects of hybridization and evolutionary constraints on secondary metabolites: the genetic architecture of phenylpropanoids in European populus species.

Directory of Open Access Journals (Sweden)

Celine Caseys

Full Text Available The mechanisms responsible for the origin, maintenance and evolution of plant secondary metabolite diversity remain largely unknown. Decades of phenotypic studies suggest hybridization as a key player in generating chemical diversity in plants. Knowledge of the genetic architecture and selective constraints of phytochemical traits is key to understanding the effects of hybridization on plant chemical diversity and ecological interactions. Using the European Populus species P. alba (White poplar and P. tremula (European aspen and their hybrids as a model, we examined levels of inter- and intraspecific variation, heritabilities, phenotypic correlations, and the genetic architecture of 38 compounds of the phenylpropanoid pathway measured by liquid chromatography and mass spectrometry (UHPLC-MS. We detected 41 quantitative trait loci (QTL for chlorogenic acids, salicinoids and flavonoids by genetic mapping in natural hybrid crosses. We show that these three branches of the phenylpropanoid pathway exhibit different geographic patterns of variation, heritabilities, and genetic architectures, and that they are affected differently by hybridization and evolutionary constraints. Flavonoid abundances present high species specificity, clear geographic structure, and strong genetic determination, contrary to salicinoids and chlorogenic acids. Salicinoids, which represent important defence compounds in Salicaceae, exhibited pronounced genetic correlations on the QTL map. Our results suggest that interspecific phytochemical differentiation is concentrated in downstream sections of the phenylpropanoid pathway. In particular, our data point to glycosyltransferase enzymes as likely targets of rapid evolution and interspecific differentiation in the 'model forest tree' Populus.

Intron-mediated alternative splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B regulates cell wall thickening during fiber development in Populus species.

Science.gov (United States)

Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

2014-02-01

Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation.

Microsatellite DNA fingerprinting, differentiation, and genetic relationships of clones, cultivars, and varieties of six poplar species from three sections of the genus Populus.

Science.gov (United States)

Rahman, Muhammad H; Rajora, Om P

2002-12-01

Accurate identification of Populus clones and cultivars is essential for effective selection, breeding, and genetic resource management programs. The unit of cultivation and breeding in poplars is a clone, and individual cultivars are normally represented by a single clone. Microsatellite DNA markers of 10 simple sequence repeat loci were used for genetic fingerprinting and differentiation of 96 clones/cultivars and varieties belonging to six Populus species (P. deltoides, P. nigra, P. balsamifera, P. trichocarpa, P. grandidentata, and P maximowiczii) from three sections of the genus. All 96 clones/cultivars could be uniquely fingerprinted based on their single- or multilocus microsatellite genotypes. The five P. grandidentata clones could be differentiated based on their single-locus genotypes, while six clones of P. trichocarpa and 11 clones of P. maximowiczii could be identified by their two-locus genotypes. Twenty clones of P. deltoides and 25 clones of P. nigra could be differentiated by their multilocus genotypes employing three loci, and 29 clones of P. balsamifera required the use of multilocus genotypes at five loci for their genetic fingerprinting and differentiation. The loci PTR3, PTR5, and PTR7 were found to be the most informative for genetic fingerprinting and differentiation of the clones. The mean number of alleles per locus ranged from 2.9 in P. trichocarpa or P. grandidentata to 6.0 in P. balsamifera and 11.2 in 96 clones of the six species. The mean number of observed genotypes per locus ranged from 2.4 in P. grandidentata to 7.4 in P. balsamifera and 19.6 in 96 clones of the six species. The mean number of unique genotypes per locus ranged from 1.3 in P. grandidentata to 3.9 in P. deltoides and 8.8 in 96 clones of the six species. The power of discrimination of the microsatellite DNA markers in the 96 clones ranged from 0.726 for PTR4 to 0.939 for PTR7, with a mean of 0.832 over the 10 simple sequence repeat loci. Clones/cultivars from the same

Genotyping-by-sequencing for Populus population genomics: an assessment of genome sampling patterns and filtering approaches.

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Martin P Schilling

Full Text Available Continuing advances in nucleotide sequencing technology are inspiring a suite of genomic approaches in studies of natural populations. Researchers are faced with data management and analytical scales that are increasing by orders of magnitude. With such dramatic advances comes a need to understand biases and error rates, which can be propagated and magnified in large-scale data acquisition and processing. Here we assess genomic sampling biases and the effects of various population-level data filtering strategies in a genotyping-by-sequencing (GBS protocol. We focus on data from two species of Populus, because this genus has a relatively small genome and is emerging as a target for population genomic studies. We estimate the proportions and patterns of genomic sampling by examining the Populus trichocarpa genome (Nisqually-1, and demonstrate a pronounced bias towards coding regions when using the methylation-sensitive ApeKI restriction enzyme in this species. Using population-level data from a closely related species (P. tremuloides, we also investigate various approaches for filtering GBS data to retain high-depth, informative SNPs that can be used for population genetic analyses. We find a data filter that includes the designation of ambiguous alleles resulted in metrics of population structure and Hardy-Weinberg equilibrium that were most consistent with previous studies of the same populations based on other genetic markers. Analyses of the filtered data (27,910 SNPs also resulted in patterns of heterozygosity and population structure similar to a previous study using microsatellites. Our application demonstrates that technically and analytically simple approaches can readily be developed for population genomics of natural populations.

Visualization of Nodulation Gene Activity on the Early Stages of Rhizobium leguminosarum bv. viciae Symbiosis

Czech Academy of Sciences Publication Activity Database

Chovanec, Pavel; Novák, Karel

2005-01-01

Roč. 50, č. 4 (2005), s. 323-331 ISSN 0015-5632 R&D Projects: GA ČR GA521/03/0192 Institutional research plan: CEZ:AV0Z50200510 Keywords : nodulation * rhizobium leguminosarum * vicia tetrasperma Subject RIV: EE - Microbiology, Virology Impact factor: 0.918, year: 2005

PtrWRKY19, a novel WRKY transcription factor, contributes to the regulation of pith secondary wall formation in Populus trichocarpa

OpenAIRE

Li Yang; Xin Zhao; Fan Yang; Di Fan; Yuanzhong Jiang; Keming Luo

2016-01-01

WRKY proteins are one of the largest transcription factor families in higher plants and play diverse roles in various biological processes. Previous studies have shown that some WRKY members act as negative regulators of secondary cell wall formation in pith parenchyma cells. However, the regulatory mechanism of pith secondary wall formation in tree species remains largely unknown. In this study, PtrWRKY19 encoding a homolog of Arabidopsis WRKY12 was isolated from Populus trichocarpa. PtrWRKY...

Efeito da aplicação de calcário em estacas de Populus deltoides Bartr. ex Marsh cultivadas em vaso

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Jean Gabriel Medeiros da Silva

2002-01-01

Full Text Available This work intended to study the behavior of Populus deltoides regarding its development when submitted to different doses of lime. The research was carried out in the Silviculture Tecnology Center, at Universidade Federal de Santa Maria, Santa Maria - RS. The experiment was constituted by forty eight (48 experimental units completely randomized, with six (06 treatments and eight repetitions (08. Each experimental unit was constituted by a vase of three liters containing only one shoot cutting of Populus deltoides. The treatments were constituted by five different doses (T2: 7 tons of lime/ha; T3: 14 tons of lime/ha; T4: 21 tons of lime/ha; T5: 29 tons of lime/ha; T6: 38 tons of lime/ha plus the testimony, determined with base in the soil analysis used in the experiment. The plants were evaluated, after 120 days of the plantation date, considering its growth in height, its diameter of the neck and its weigh dry of the aerial part. The best average were reached by the treatments without lime and with seven tons of lime for ha in all the parameters observed. The other treatments presented inferior averages, which do not possess significant difference to each other at the level of 5%, for all the observed parameters.

Incremento volumétrico de un ensayo con híbridos de Populus spp.

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Oscar Vallejos-Barra

2015-09-01

Full Text Available El aumento de los requerimientos energéticos demandados por la sociedad ha impulsado el interés por establecer ensayos para seleccionar especies o híbridos que en el menor tiempo posible generen la mayor cantidad de volumen o biomasa. En esta investigación, se determinó el incremento medio anual del volumen de un ensayo con híbridos de Populus con la finalidad de dar a conocer la potencialidad de los híbridos del catálogo del Centro Tecnológico del Álamo (CTA de la Universidad de Talca. De este catálogo se escogieron los seis híbridos más promisorios y se compararon con seis híbridos comerciales. El ensayo se estableció a 10 km al norte de la ciudad de Talca, en la estación experimental Panguilemo de la Universidad de Talca. En terreno se midió el diámetro basal y la altura por tres años a las seis plantas centrales de cada parcela, con cuatro repeticiones por híbrido para ambas densidades de plantación (5.000 y 10.000 plantas por hectárea. El volumen se calculó utilizando el exponente mórfico de un Paracono. El incremento volumétrico varió entre 5,306 y 15,828 m3 ha-1 año-1, detectando diferencias significativas entre los híbridos. El grupo de mayor productividad estuvo compuesto por cinco híbridos todos del catálogo del CTA. Este resultado demuestra que si se desea una mayor productividad en plantaciones dendroenergéticas que utilicen híbridos de Populus se deberían considerar algunos de los híbridos del catálogo del Centro Tecnológico del Álamo (CTA de la Universidad de Talca.

The applications of populus fiber in removal of Cr{sup (VI)} from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Li, Miaomiao; Gong, Yumei, E-mail: ymgong@dlpu.edu.cn; Lyu, Aichao; Liu, Yuanfa, E-mail: morning309@126.com; Zhang, Hong, E-mail: zhang_hong1234@sina.com

2016-10-15

Highlights: • A sorbent for heavy metal ions based on populus fibers is prepared by a green way. • The chromium adsorption on the sorbent accords with the pseudo-second-order kinetics. • The proposed adsorption involves static attraction and chelation by the sorbent on chromium. • The sorbent is expected to be applied in universal conditions. - Abstract: The surface modification of natural materials to be applied in removal of Cr{sup (VI)} from aqueous solutions has attracted much attention. A natural sorbent for Cr{sup (VI)} based on natural populus fibers (PF) is prepared by transforming the cyano groups (AN) in polyacrylonitriles (PAN) grafted from PF into amidoxime groups (AO), which has strong ability to attract and chelate heavy metal ions. The prepared sorbent is characterized by Fourier Transform Infrared Spectra (FT-IR), thermogravimetric analysis (TGA), solid-state nuclear magnetic resonance ({sup 13}C NMR) and scanning electron microscope (SEM). As potassium dichromate solution (K{sub 2}Cr{sub 2}O{sub 7}) is used as a target solution for detecting adsorption capacity of the sorbent, the adsorption kinetics of the sorbent for chromiun is consistent with the pseudo-second-order kinetic model by analyzing the adsorption amount as a function of the sorbent dispersed duration in solution at pH = 2. The expected adsorption mechanism is that the Cr{sup (VI)} in anionic ions Cr{sub 2}O{sub 7}{sup 2−} and HCrO{sub 4}{sup −} are adsorbed through electrostatic attraction but when Cr{sup (VI)} is reduced to Cr{sup (III)} by AO, the electronegative nitrogen and oxygen in AO chelate it through coordination bond. The as-prepared PF derivant with high adsorption efficiency of chromium 180.5 mg/g (3.47 mmol/g), low cost, reusability and greenly preparation process suggests that the development of natural PF as a sorbent in removal of Cr{sup (VI)} from aqueous solutions is a destined significant approach.

Short Rotation Forestry (SRF in a Mediterranean Environment Under Limited Energy Inputs

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Antonio Sergio De Franchi

2010-10-01

Full Text Available The aim of this work is comparing the two year performance (diameter, total height and mortality of twenty tree and shrub species in a semi arid environment. The research also wants to supply recommendation on the agronomic cropping techniques in areas where rainfall is the main limiting factor and water use is strictly limited. Woody biomass is gaining increasing importance for energy production in Italy. During the last five years, roughly 5000 ha of Short Rotation Forestry (SRF have been planted, mostly in northern Italy, especially using poplar clones. However, in Southern Italy, due to the poor rainfall and the lack of knowledge existing on the species to use, few groves have been established. The studied groves were set in December 2005 in a Mediterranean area where the total year rainfall is not higher than 600 mm (mostly in autumn and winter. Twenty species (Salix cinerea, Ulmus carpinifolia, Corylus avellana, Spartium junceum, Acer saccharinum, Morus alba, Saphora japonica, Eleagnus angustifolia, Fraxinus angustifolia (var oxicarpa, Sambucus nigra, Robinia pseudoacacia, Populus nigra, Albizia julibrissis, Populus alba, Salix alba, Ailanthus altissima, Alnus cordata, Ficus carica, Eucalyptus camaldulensis, Celtis australis were planted in “collection” plots and set in singular plots on single rows (3 m X 0.5 m spacing. Six species (R. pseudoacacia, P. nigra, P. alba, S. nigra, E. camaldulensis, and A. altissima were planted in eighteen random “experimental” split-plots, using single and twin rows (0.5 m spacing between plants. Plots had a rectangular plant spacing (3 m between singular and twin rows, 0.5 m on each row. Plant density was roughly 6670 cuttings ha-1 in “collection” plots with singular rows and 10950 cuttings ha-1 in “experimental” plots using single and twin rows. The expected harvest interval ranges from 2 to 5 years, depending on the first results. In the “collection” plots, the first results showed

Short Rotation Forestry (SRF in a Mediterranean Environment Under Limited Energy Inputs

Directory of Open Access Journals (Sweden)

Stella Lovelli

2010-12-01

Full Text Available The aim of this work is comparing the two year performance (diameter, total height and mortality of twenty tree and shrub species in a semi arid environment. The research also wants to supply recommendation on the agronomic cropping techniques in areas where rainfall is the main limiting factor and water use is strictly limited. Woody biomass is gaining increasing importance for energy production in Italy. During the last five years, roughly 5000 ha of Short Rotation Forestry (SRF have been planted, mostly in northern Italy, especially using poplar clones. However, in Southern Italy, due to the poor rainfall and the lack of knowledge existing on the species to use, few groves have been established. The studied groves were set in December 2005 in a Mediterranean area where the total year rainfall is not higher than 600 mm (mostly in autumn and winter. Twenty species (Salix cinerea, Ulmus carpinifolia, Corylus avellana, Spartium junceum, Acer saccharinum, Morus alba, Saphora japonica, Eleagnus angustifolia, Fraxinus angustifolia (var oxicarpa, Sambucus nigra, Robinia pseudoacacia, Populus nigra, Albizia julibrissis, Populus alba, Salix alba, Ailanthus altissima, Alnus cordata, Ficus carica, Eucalyptus camaldulensis, Celtis australis were planted in “collection” plots and set in singular plots on single rows (3 m X 0.5 m spacing. Six species (R. pseudoacacia, P. nigra, P. alba, S. nigra, E. camaldulensis, and A. altissima were planted in eighteen random “experimental” split-plots, using single and twin rows (0.5 m spacing between plants. Plots had a rectangular plant spacing (3 m between singular and twin rows, 0.5 m on each row. Plant density was roughly 6670 cuttings ha-1 in “collection” plots with singular rows and 10950 cuttings ha-1 in “experimental” plots using single and twin rows. The expected harvest interval ranges from 2 to 5 years, depending on the first results. In the “collection” plots, the first results showed

Identification and characterization of nuclear genes involved in photosynthesis in Populus

Science.gov (United States)

2014-01-01

Background The gap between the real and potential photosynthetic rate under field conditions suggests that photosynthesis could potentially be improved. Nuclear genes provide possible targets for improving photosynthetic efficiency. Hence, genome-wide identification and characterization of the nuclear genes affecting photosynthetic traits in woody plants would provide key insights on genetic regulation of photosynthesis and identify candidate processes for improvement of photosynthesis. Results Using microarray and bulked segregant analysis strategies, we identified differentially expressed nuclear genes for photosynthesis traits in a segregating population of poplar. We identified 515 differentially expressed genes in this population (FC ≥ 2 or FC ≤ 0.5, P photosynthesis by the nuclear genome mainly involves transport, metabolism and response to stimulus functions. Conclusions This study provides new genome-scale strategies for the discovery of potential candidate genes affecting photosynthesis in Populus, and for identification of the functions of genes involved in regulation of photosynthesis. This work also suggests that improving photosynthetic efficiency under field conditions will require the consideration of multiple factors, such as stress responses. PMID:24673936

Biological diversity of Salix taxa in Cu, Pb and Zn phytoextraction from soil.

Science.gov (United States)

Mleczek, Mirosław; Rutkowski, Paweł; Goliński, Piotr; Kaczmarek, Zygmunt; Szentner, Kinga; Waliszewska, Bogusława; Stolarski, Mariusz; Szczukowski, Stefan

2017-02-01

The aim of the study was to estimate the efficiency of copper (Cu), lead (Pb) and zinc (Zn) phytoextraction by 145 Salix taxa cultivated in an area affected by industrial activity. Survivability and biomass of plants were also analyzed. The highest Cu, Pb and Zn content in shoots was 33.38 ± 2.91 (S. purpurea × viminalis 8), 24.64 ± 1.97 (S. fragilis 1) and 58.99 ± 4.30 (S. eriocephala 7) mg kg -1 dry weight, respectively. In the case of unwashed leaves, the highest content of these metals was 135.06 ± 8.14 (S. purpurea 26), 67.98 ± 5.27 (S. purpurea 45) and 142.56 ± 12.69 (S. alba × triandra 2) mg kg -1 dw, while in washed leaves it was 106.02 ± 11.12 (S. purpurea 45), 55.06 ± 5.75 (S. purpurea 45) and 122.87 ± 12.33 (S. alba × triandra 2) mg kg -1 dw, respectively. The differences between the highest and lowest values for Cu, Pb and Zn were 545%, 20500% and 535% in shoots; 2692%, 2560% and 7500% in unwashed leaves; and 3286%, 2221% and 6950% in washed leaves, respectively. S. acutifolia was able to effectively accumulate all three metals jointly, producing shoots that were well developed in both length and diameter when compared with the other tested willows-an ability that would suggest its high suitability for practical application.

Local variability in growth and reproduction of Salix arctica in the High Arctic

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Noémie Boulanger-Lapointe

2016-06-01

Full Text Available Arctic terrestrial ecosystems are heterogeneous because of the strong influences of microtopography, soil moisture and snow accumulation on vegetation distribution. The interaction between local biotic and abiotic factors and global climate patterns will influence species responses to climate change. Salix arctica (Arctic willow is a structuring species, ubiquitous and widespread, and as such is one of the most important shrub species in the High Arctic. In this study, we measured S. arctica reproductive effort, early establishment, survival and growth in the Zackenberg valley, north-east Greenland. We sampled four plant communities that varied with respect to snow conditions, soil moisture, nutrient content and plant composition. We found large variability in reproductive effort and success with total catkin density ranging from 0.6 to 66 catkins/m2 and seedling density from <1 to 101 seedlings/m2. There were also major differences in crown area increment (4–23 cm2/year and stem radial growth (40–74 µm/year. The snowbed community, which experienced a recent reduction in snow cover, supported young populations with high reproductive effort, establishment and growth. Soil nutrient content and herbivore activity apparently did not strongly constrain plant reproduction and growth, but competition by Cassiope tetragona and low soil moisture may inhibit performance. Our results show that local environmental factors, such as snow accumulation, have a significant impact on tundra plant response to climate change and will affect the understanding of regional vegetation response to climate change.

Roles of gibberellin catabolism and signaling in growth and physiological response to drought and short-day photoperiods in Populus trees.

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Christine Zawaski

Full Text Available Survival and productivity of perennial plants in temperate zones are dependent on robust responses to prolonged and seasonal cycles of unfavorable conditions. Here we report whole-genome microarray, expression, physiological, and transgenic evidence in hybrid poplar (Populus tremula × Populus alba showing that gibberellin (GA catabolism and repressive signaling mediates shoot growth inhibition and physiological adaptation in response to drought and short-day (SD induced bud dormancy. Both water deprivation and SDs elicited activation of a suite of poplar GA2ox and DELLA encoding genes. Poplar transgenics with up-regulated GA 2-oxidase (GA2ox and DELLA domain proteins showed hypersensitive growth inhibition in response to both drought and SDs. In addition, the transgenic plants displayed greater drought resistance as evidenced by increased pigment concentrations (chlorophyll and carotenoid and reductions in electrolyte leakage (EL. Comparative transcriptome analysis using whole-genome microarray showed that the GA-deficiency and GA-insensitivity, SD-induced dormancy, and drought response in poplar share a common regulon of 684 differentially-expressed genes, which suggest GA metabolism and signaling plays a role in plant physiological adaptations in response to alterations in environmental factors. Our results demonstrate that GA catabolism and repressive signaling represents a major route for control of growth and physiological adaptation in response to immediate or imminent adverse conditions.

The effect of hydrological regime on the metal bioavailability for the wetland plant species Salix cinerea

International Nuclear Information System (INIS)

Vandecasteele, Bart; Quataert, Paul; Tack, Filip M.G.

2005-01-01

The hydrological conditions on a site constitute one of the many factors that may affect the availability of potentially toxic trace metals for uptake by plants. Bioavailability of Cd, Mn and Zn in a contaminated dredged sediment-derived soil under different hydrological regimes was determined by measuring metal uptake by the wetland plant species Salix cinerea, both in field circumstances and in a greenhouse experiment. Longer submersion periods in the field caused lower Cd concentrations in leaves and bark. The wetland hydrological regime in the greenhouse experiment resulted in normal Cd and Zn concentrations in the leaves, while the upland hydrological regime resulted in elevated Cd and Zn concentrations in the leaves. Field observations and the greenhouse experiment suggest that a hydrological regime that creates or sustains a wetland is a potential management option that reduces metal bioavailability to willows. This would constitute a safe management option of metal-polluted, willow-dominated wetlands provided that wetland conditions can be maintained throughout the full growing season. - A hydrological regime aiming at wetland creation is a potential management option that favors reducing Cd plant availability in polluted freshwater wetlands

SRC-willow (Salix viminalis) as a resource for flower-visiting insects

Energy Technology Data Exchange (ETDEWEB)

Reddersen, J. [National Environmental Research Institute, Ronde (Denmark). Dept. of Landscape Ecology

2001-07-01

The potential habitat value of commercial short rotation coppice (SRC)-willow plantations for flower-visiting insects was investigated. During 1998-2000, at a single typical intensive Danish farmland site, 11 Salix viminalis plantations were sampled by late April to quantify willow catkin abundance and flower sex. Mean plantation size was 1.1 ha and included one or more of clones: orm, rapp, ulv, jorr, christina and jorrun. Plot-year means of catkin abundance and of proportion of willows flowering were related to the coppicing cycle, i.e. the number of growth years since last harvest of plot ('year' 0-4). In 1998, the ground layer vegetation was sampled. Monitoring flower-visiting insects by means of line-transect counts failed due to the local scarcity of bees. At the plantation scale, flowering was discontinuous across the harvest cycle as it was totally absent in the year immediately following harvest. In successive years (1-4), individual willows flowered frequently and, occasionally, at high abundances, and catkin abundance increased with time. Within 3-4 year of harvest cycle, all plots flowered in most years with most plots exhibiting at least some flowering in any 1 year. Thus, willow catkin abundance was generally high in the total area due to: high frequency of flowering in plots, occasional high flowering abundance, plots not being harvested simultaneously and large total number of willows within plots and landscape. Similarly, flower sex ratio, and thus flower value, varied greatly between plots while variation was damped across plots. Alternative simultaneous flower resources in ground layer vegetation were few except for Dandelion. SRC willow may constitute an important resource for bees, even under the stress of the harvest cycle, and recommendations are given for improving this biodiversity aspect. (author)

Gamma radiation effect on Populus nigra assimilatory pigments

International Nuclear Information System (INIS)

Creanga, I. A.; Tudorie, Marcela; Mocanasu, C.; Creanga, Dorina

2002-01-01

The influence of low intensity gamma radiation on the photosynthesis in young poplar saplings was studied. Black poplar (Populus nigra) was chosen due to its ecological importance, as fast growing tree species with many hybrids, in the frame of a polluted environment. Assimilatory pigments in the leaves of irradiated saplings were assayed using standard spectrophotometric method in acetone extract. Series of five saplings formed the experimental samples. Chlorophyll a and chlorophyll b levels appeared as diminished in exposed samples in comparison to the controls. Linear regression was established in every case, the line slope showing the higher effect in chlorophyll b. Carotene pigments presented a slight increasing tendency in the exposed samples. Assimilatory pigment sum was shown to be affected by the same decreasing tendency. Student t-test was applied (two tailed, pair type) to reveal statistical significance of observed modifications. Though not very deep, the modifications induced by exposure to gamma radiation of low intensity (comparable to the local atmospheric variations, caused by both natural and artificial sources) represent putative inhibitory factors in young plant photosynthesis. The main mechanism of radiation action seems to be water radiolysis, triggering peroxide cascade, generally producing toxic products for the cell metabolism. Nevertheless, living cell ability to repair some damages caused by external stress could be revealed in the present case by the enhancing tendency of the carotenes which sustain photosynthesis as secondary pigments. (authors)

Response of Boreal forest tree canopy cover to chronic gamma irradiation

International Nuclear Information System (INIS)

Amiro, B.D.

1994-01-01

A section of the Canadian Boreal forest was irradiated chronically by a point source of 137 Cs from 1973 to 1986. Tree canopy cover was measured at permanently marked locations during the pre-irradiation, irradiation and post-irradiation phases, spanning a period of two decades. The tree canopy was severely affected at dose rates greater than 10 mGy/h delivered chronically. The canopy of sensitive coniferous tree species, such as Abies balsamea and Picea Mariana, decreased at dose rates greater than 2 mGy/h, but in some cases the tree canopy was replaced by more resistant species, such as Populus tremuloides and Salix bebbiana. Effects on canopy cover could not be detected at dose rates less than 0.1 mGy/h. Even at dose rates of 5 mGy/h, the forest canopy is recovering six years after irradiation stopped. (author)

Human settlement and its influencing factors during the historicalperiod in an oasis-desert transition zone of Dunhuang, Hexi Corridor,northwest China

Science.gov (United States)

Li, H.; Dong, G.; Zhang, S.

2017-12-01

Many ancient cities and settlement sites have been found in Lucaogou, an ancient oasis near Dunhuangcity in northwest China. These settlements indicate that humans inhabited this area during the historicalperiod. However, the chronology and subsistence practices of this area remain unclear. Based on newdata from radiocarbon dating, macrobotanical analysis, and the synthesis of historical documents andhigh-resolution paleoclimatic records, we discuss the inter-relationship between human settlements andplant resource utilization strategies at Lucaogou ancient oasis during historical period. Our resultsindicate that these ancient sites in Lucaogou area were built between the Han dynasty (202 BC-AD 220)and the Ming dynasty (AD 1368-AD 1644). People mainly used foxtail millet, broomcorn millet, barleyand three types of wood (Tamarix, Salix, Populus), probably as fuel for cooking. Human settlement intensityin the area during the historical period was primarily influenced by political situations, whichmight also have been affected by fluctuations in precipitation.

Epiphytic vegetation of Populus balsamifera and its significance as an air pollution indicator in Sudbury, Ontario

Energy Technology Data Exchange (ETDEWEB)

Leblanc, F; Rao, D N; Comeau, G

1972-01-01

Indices of atmospheric purity (IAP) of 31 sites, selected in the SO/sub 2/-polluted as well as in the nonpolluted areas around Sudbury were determined on the basis of number, frequency-coverage, and resistance factor of the epiphytes of Populus balsamifera. Based on these indices, arranged into convenient ranges, the investigated area was delimited into five different IAP zones. These zones were then compared with SO/sub 2/ pollution zones based on the ground-level average concentration of the gas prevailing in the area. From this comparison it is clear that the biological method provides a valid, quick, and economical way for assessing and mapping the long-range effect of pollution of a given area.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

Science.gov (United States)

Dötterl, Stefan; Glück, Ulrike; Jürgens, Andreas; Woodring, Joseph; Aas, Gregor

2014-01-01

In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward) than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i) to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues) in dioecious sallow, Salix caprea, ii) to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii) to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Floral reward, advertisement and attractiveness to honey bees in dioecious Salix caprea.

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Stefan Dötterl

Full Text Available In dioecious, zoophilous plants potential pollinators have to be attracted to both sexes and switch between individuals of both sexes for pollination to occur. It often has been suggested that males and females require different numbers of visits for maximum reproductive success because male fertility is more likely limited by access to mates, whereas female fertility is rather limited by resource availability. According to sexual selection theory, males therefore should invest more in pollinator attraction (advertisement, reward than females. However, our knowledge on the sex specific investment in floral rewards and advertisement, and its effects on pollinator behaviour is limited. Here, we use an approach that includes chemical, spectrophotometric, and behavioural studies i to elucidate differences in floral nectar reward and advertisement (visual, olfactory cues in dioecious sallow, Salix caprea, ii to determine the relative importance of visual and olfactory floral cues in attracting honey bee pollinators, and iii to test for differential attractiveness of female and male inflorescence cues to honey bees. Nectar amount and sugar concentration are comparable, but sugar composition varies between the sexes. Olfactory sallow cues are more attractive to honey bees than visual cues; however, a combination of both cues elicits the strongest behavioural responses in bees. Male flowers are due to the yellow pollen more colourful and emit a higher amount of scent than females. Honey bees prefer the visual but not the olfactory display of males over those of females. In all, the data of our multifaceted study are consistent with the sexual selection theory and provide novel insights on how the model organism honey bee uses visual and olfactory floral cues for locating host plants.

Elimination behaviour and soil mineral nitrogen load in an organic system with lactating sows – comparing pasture based systems with and without access to poplar (Populus sp.) trees

DEFF Research Database (Denmark)

Jakobsen, Malene; Hermansen, John Erik; Andersen, Heidi Mai-Lis

2017-01-01

There is an urgent need to introduce innovative strategies in the current free-range pig production to improve the environmental performance. Based on previous experiences, inclusion of a zone with poplar (Populus sp.) trees in individual sow paddocks was hypothesized to improve the system’s nitr...

Intron-Mediated Alternative Splicing of WOOD-ASSOCIATED NAC TRANSCRIPTION FACTOR1B Regulates Cell Wall Thickening during Fiber Development in Populus Species1[W

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Zhao, Yunjun; Sun, Jiayan; Xu, Peng; Zhang, Rui; Li, Laigeng

2014-01-01

Alternative splicing is an important mechanism involved in regulating the development of multicellular organisms. Although many genes in plants undergo alternative splicing, little is understood of its significance in regulating plant growth and development. In this study, alternative splicing of black cottonwood (Populus trichocarpa) wood-associated NAC domain transcription factor (PtrWNDs), PtrWND1B, is shown to occur exclusively in secondary xylem fiber cells. PtrWND1B is expressed with a normal short-transcript PtrWND1B-s as well as its alternative long-transcript PtrWND1B-l. The intron 2 structure of the PtrWND1B gene was identified as a critical sequence that causes PtrWND1B alternative splicing. Suppression of PtrWND1B expression specifically inhibited fiber cell wall thickening. The two PtrWND1B isoforms play antagonistic roles in regulating cell wall thickening during fiber cell differentiation in Populus spp. PtrWND1B-s overexpression enhanced fiber cell wall thickening, while overexpression of PtrWND1B-l repressed fiber cell wall thickening. Alternative splicing may enable more specific regulation of processes such as fiber cell wall thickening during wood formation. PMID:24394777

Evolutionary Quantitative Genomics of Populus trichocarpa.

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Ilga Porth

Full Text Available Forest trees generally show high levels of local adaptation and efforts focusing on understanding adaptation to climate will be crucial for species survival and management. Here, we address fundamental questions regarding the molecular basis of adaptation in undomesticated forest tree populations to past climatic environments by employing an integrative quantitative genetics and landscape genomics approach. Using this comprehensive approach, we studied the molecular basis of climate adaptation in 433 Populus trichocarpa (black cottonwood genotypes originating across western North America. Variation in 74 field-assessed traits (growth, ecophysiology, phenology, leaf stomata, wood, and disease resistance was investigated for signatures of selection (comparing QST-FST using clustering of individuals by climate of origin (temperature and precipitation. 29,354 SNPs were investigated employing three different outlier detection methods and marker-inferred relatedness was estimated to obtain the narrow-sense estimate of population differentiation in wild populations. In addition, we compared our results with previously assessed selection of candidate SNPs using the 25 topographical units (drainages across the P. trichocarpa sampling range as population groupings. Narrow-sense QST for 53% of distinct field traits was significantly divergent from expectations of neutrality (indicating adaptive trait variation; 2,855 SNPs showed signals of diversifying selection and of these, 118 SNPs (within 81 genes were associated with adaptive traits (based on significant QST. Many SNPs were putatively pleiotropic for functionally uncorrelated adaptive traits, such as autumn phenology, height, and disease resistance. Evolutionary quantitative genomics in P. trichocarpa provides an enhanced understanding regarding the molecular basis of climate-driven selection in forest trees and we highlight that important loci underlying adaptive trait variation also show

The Populus superoxide dismutase gene family and its responses to drought stress in transgenic poplar overexpressing a pine cytosolic glutamine synthetase (GS1a.

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Juan Jesús Molina-Rueda

Full Text Available BACKGROUND: Glutamine synthetase (GS plays a central role in plant nitrogen assimilation, a process intimately linked to soil water availability. We previously showed that hybrid poplar (Populus tremula X alba, INRA 717-1B4 expressing ectopically a pine cytosolic glutamine synthetase gene (GS1a display enhanced tolerance to drought. Preliminary transcriptome profiling revealed that during drought, members of the superoxide dismutase (SOD family were reciprocally regulated in GS poplar when compared with the wild-type control, in all tissues examined. SOD was the only gene family found to exhibit such patterns. RESULTS: In silico analysis of the Populus genome identified 12 SOD genes and two genes encoding copper chaperones for SOD (CCSs. The poplar SODs form three phylogenetic clusters in accordance with their distinct metal co-factor requirements and gene structure. Nearly all poplar SODs and CCSs are present in duplicate derived from whole genome duplication, in sharp contrast to their predominantly single-copy Arabidopsis orthologs. Drought stress triggered plant-wide down-regulation of the plastidic copper SODs (CSDs, with concomitant up-regulation of plastidic iron SODs (FSDs in GS poplar relative to the wild type; this was confirmed at the activity level. We also found evidence for coordinated down-regulation of other copper proteins, including plastidic CCSs and polyphenol oxidases, in GS poplar under drought conditions. CONCLUSIONS: Both gene duplication and expression divergence have contributed to the expansion and transcriptional diversity of the Populus SOD/CCS families. Coordinated down-regulation of major copper proteins in drought-tolerant GS poplars supports the copper cofactor economy model where copper supply is preferentially allocated for plastocyanins to sustain photosynthesis during drought. Our results also extend previous findings on the compensatory regulation between chloroplastic CSDs and FSDs, and suggest that this

Gender differences in Salix myrsinifolia at the pre-reproductive stage are little affected by simulated climatic change

Energy Technology Data Exchange (ETDEWEB)

Nybakken, L.; Julkunen-Tiitto, R. [Univ. of Eastern Finland. Dept. of Biology, Joensuu (Finland)

2013-04-15

Females of dioecious species are known often to prioritize defense, while males grow faster. As climatic change is known to influence both growth and defense in plants, it would be important to know whether it affects the sexes of dioecious species differently. This could have impacts on future sex ratios in nature. We grew four clones of each sex of Salix myrsinifolia in greenhouse chambers under ambient conditions, enhanced temperature, enhanced CO{sub 2} or enhanced temperature? + enhanced CO{sub 2}. The females had the greatest growth and also the highest levels of phenolic compounds in twigs, while in leaves some compounds were higher in males, some in females. Enhanced CO{sub 2} increased growth equally in both sexes, while growth was not affected by elevated temperature. Phenolic compounds in twigs were, however, lowered under elevated temperature. The gender differences were not strongly affected by the simulated climatic changes, but the effects seen on some highly concentrated compounds may be important. We interpret the intensive growth at pre-reproductive phase as a strategy in females to get an initial advantage before later periods with fewer resources available for growth. (Author)

Changes in photosynthesis, mesophyll conductance to CO2, and isoprenoid emissions in Populus nigra plants exposed to excess nickel

International Nuclear Information System (INIS)

Velikova, Violeta; Tsonev, Tsonko; Loreto, Francesco; Centritto, Mauro

2011-01-01

Poplar (Populus nigra) plants were grown hydroponically with 30 and 200 μM Ni (Ni 30 and Ni 200 ). Photosynthesis limitations and isoprenoid emissions were investigated in two leaf types (mature and developing). Ni stress significantly decreased photosynthesis, and this effect depended on the leaf Ni content, which was lower in mature than in developing leaves. The main limitations to photosynthesis were attributed to mesophyll conductance and metabolism impairment. In Ni-stressed developing leaves, isoprene emission was significantly stimulated. We attribute such stimulation to the lower chloroplastic [CO 2 ] than in control leaves. However chloroplastic [CO 2 ] did not control isoprene emission in mature leaves. Ni stress induced the emission of cis-β-ocimene in mature leaves, and of linalool in both leaf types. Induced biosynthesis and emission of isoprenoids reveal the onset of antioxidant processes that may also contribute to reduce Ni stress, especially in mature poplar leaves. - Graphical abstract: Visible damage caused by Ni treatment. 1 - Ni 0 (control plants); 2 - Ni 200 ; M = mature and D = developing Populus nigra leaves. Display Omitted Highlights: → We study the effect of Ni pollution on photosynthesis and isoprenoid emissions. → Ni stress significantly decreases photosynthesis. The main limitations are attributed to mesophyll conductance and metabolism impairment. → Constitutive isoprene emission was significantly stimulated in Ni-stressed leaves. Exposure to enhanced Ni concentration induces cis-beta-ocimene and linalool emissions. - The study reveals consequences of Ni stress on plant physiology, namely increasing diffusional limitation to photosynthesis and isoprenoid emissions.

Wood Usage and Fire Veneration in the Pamir, Xinjiang, 2500 yr BP.

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Hui Shen

Full Text Available Located on the Pamir Plateau in Xinjiang Province, China, the Ji'erzankale Necropolis dates back to 2500 yr BP. Many materials that have been unearthed in this cemetery, including shoo konghou (musical instrument, bronze mirrors and glass beads, suggest cultural transference between East and West. Furthermore, small-sized and rounded fire altars made from sweet-scented Sabina were found for the first time and regarded as implements for fire veneration. We identified 70 wooden objects from 25 tombs within the Necropolis, and found that each object had been made from one of seven tree species. Analysis revealed that the inhabitants of the region mainly used the most widely available types of wood, namely Betula and Populus. People also specifically chose inflammable Populus wood to make hearth boards and hand drills (both are used for making fire by drilling, rigid Betula wood to craft wooden plates. Salix was used for fashioning wooden sticks, while sweet-scented Sabina was the preferred choice for making fire altars. Lonicera was selected for arrow shaft manufacture and Fraxinus syriaca, which has a beautiful grain, was chosen for making musical instruments. Conscious selection of different types of wood indicates that people of the Pamir Plateau were aware of the properties of various types of timbers, and were able to exploit these properties to the full. In turn, this demonstrates their wisdom and their ability to survive in, and adapt to, their local environment.

Nesting ecology of Greater Sandhill Cranes (Grus canadensis tabida) in riparian and palustrine wetlands of eastern Idaho

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McWethy, D.B.; Austin, J.E.

2009-01-01

Little information exists on breeding Greater Sandhill Cranes (Grus canadensis tabida) in riparian wetlands of the Intermountain West. We examined the nesting ecology of Sandhill Cranes associated with riparian and palustrine wetlands in the Henry's Fork Watershed in eastern Idaho in 2003. We located 36 active crane nests, 19 in riparian wetlands and 17 in palustrine wetlands. Nesting sites were dominated by rushes (Juncus spp.), sedges (Carex spp.), Broad-leaved Cattail (Typha latifolia) and willow (Salix spp.), and adjacent foraging areas were primarily composed of sagebrush (Artemisia spp.), cinquefoil (Potentilla spp.),Rabbitbrush (Ericameria bloomeri) bunch grasses, upland forbs, Quaking Aspen (Populus tremuloides) and cottonwood (Populus spp.). Mean water depth surrounding nests was 23 cm (SD = 22). A majority of nests (61%) were surrounded by vegetation between 3060 cm, 23% by vegetation 60 cm in height. We were able to determine the fate of 29 nests, of which 20 were successful (69%). Daily nest survival was 0.986 (95% LCI 0.963, UCI 0.995), equivalent to a Mayfield nest success of 0.654 (95% LCI 0.324, UCI 0.853). Model selection favored models with the covariates vegetation type, vegetation height, and water depth. Nest survival increased with increasing water depth surrounding nest sites. Mean water depth was higher around successful nests (30 cm, SD = 21) than unsuccessful nests (15 cm, SD 22). Further research is needed to evaluate the relative contribution of cranes nesting in palustrine and riparian wetlands distributed widely across the Intermountain West.

Scale dependence of disease impacts on quaking aspen (Populus tremuloides) mortality in the southwestern United States

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Bell, David M.; Bradford, John B.; Lauenroth, William K.

2015-01-01

Depending on how disease impacts tree exposure to risk, both the prevalence of disease and disease effects on survival may contribute to patterns of mortality risk across a species' range. Disease may accelerate tree species' declines in response to global change factors, such as drought, biotic interactions, such as competition, or functional traits, such as allometry. To assess the role of disease in mediating mortality risk in quaking aspen (Populus tremuloides), we developed hierarchical Bayesian models for both disease prevalence in live aspen stems and the resulting survival rates of healthy and diseased aspen near the species' southern range limit using 5088 individual trees on 281 United States Forest Service Forest Inventory and Analysis plots in the southwestern United States.

Population resources of an endangered species Salix lapponum L. in Polesie Lubelskie Region (eastern Poland

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Magdalena Pogorzelec

2014-12-01

Full Text Available This research, carried out in the years 2011–2013, aimed to evaluate Salix lapponum stands in the peat bogs of Polesie Lubelskie Region as well as to determine the condition of the population and the changes that have taken place since the 1950’s. An inventory carried out in 25 stands of S. lapponum known from the literature shows that the number of its stands has decreased by 80% in Polesie Lubelskie Region. In all the confirmed locations, a decrease in population numbers was also found in relation to the data known from the literature since the 1950’s. In the majority of the population locations that were considered to be extinct, there were no significant changes in habitat conditions, and ecological succession and changes in hydrological conditions could have been the cause of habitat changes only at a few sites. In the light of the study, the preservation of the S. lapponum population in Polesie Lubelskie seems to be impossible if appropriate active conservation measures are not taken immediately. Because area-based conservation, which covers most of the habitats of the studied species, does not bring the expected results, the possibility of ex situ conservation and enlargement of the populations existing in the natural environment in peat bog ecosystems in Polesie should be explored.

Rapid production of trees. [Acer platanoides, Fraxinus excelsior, Quercus robus, Sorbus, Picea, and Abies spp. , Betula verrucose, Populus trichocarpa

Energy Technology Data Exchange (ETDEWEB)

Haarjorg, A.

1976-01-01

Seedlings of Acer platanoides approximately 2 m tall were produced in southern Norway in one year by seed stratification indoors. Similar results were obtained with Fraxinus excelsior, Quercus robus and Sorbus spp. Trails were also carried out with Betula verrucose (B. pendula), Populus trichocarpa, Picea spp., Abies spp., and other conifers. In all trials growth was increased when plants were raised in a plastic house, and depended on the time that Spring growth was started or whether supplementary light was given and also depended on the seed strain. For northern and high altitude strains it was important to maintain critical day length.

Extensive transcriptome changes during natural onset and release of vegetative bud dormancy in Populus

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Glenn Thomas Howe

2015-12-01

Full Text Available To survive winter, many perennial plants become endodormant, a state of suspended growth maintained even in favorable growing environments. To understand vegetative bud endodormancy, we collected paradormant, endodormant, and ecodormant axillary buds from Populus trees growing under natural conditions. Of 44,441 Populus gene models analyzed using NimbleGen microarrays, we found that 1,362 (3.1% were differentially expressed among the three dormancy states, and another 429 (1.0% were differentially expressed during only one of the two dormancy transitions (false discovery rate p-value < 0.05. Of all differentially expressed genes, 69% were down-regulated from paradormancy to endodormancy, which was expected given the lower metabolic activity associated with endodormancy. Dormancy transitions were accompanied by changes in multiple genes associated with DNA methylation (via RNA-directed DNA methylation and histone modifications (via Polycomb Repressive Complex 2, confirming and extending knowledge of chromatin modification as major features of dormancy transitions. Among the chromatin-associated genes, we found two genes similar to SPT (SUPPRESSOR OF TY that were strongly up-regulated during endodormancy. Transcription factor genes and gene sets that were atypically up-regulated during endodormancy include a gene that seems to encode a trihelix transcription factor and genes associated with proteins involved in responses to ethylene, cold, and other abiotic stresses. These latter transcription factors include ETHYLENE INSENSITIVE 3 (EIN3, ETHYLENE-RESPONSIVE ELEMENT BINDING PROTEIN (EBP, ETHYLENE RESPONSE FACTOR (ERF, ZINC FINGER PROTEIN 10 (ZAT10, ZAT12, and WRKY DNA-binding domain proteins. Analyses of phytohormone-associated genes suggest important changes in responses to ethylene, auxin, and brassinosteroids occur during endodormancy. We found weaker evidence for changes in genes associated with salicylic acid and jasmonic acid, and little

Songbird response to increased willow (Salix spp.) growth in Yellowstone's northern range.

Science.gov (United States)

Baril, Lisa M; Hansen, Andrew J; Renkin, Roy; Lawrence, Rick

2011-09-01

After nearly a century of height suppression, willows (Salix spp.) in the northern range of Yellowstone National Park, U.S.A., are increasing in height growth as a possible consequence of wolf (Canis lupus) restoration, climate change, or other factors. Regardless of the drivers, the recent release of this rare but important habitat type could have significant implications for associated songbirds that are exhibiting declines in the region. Our objective was to evaluate bird response to releasing willows by comparing willow structure and bird community composition across three willow growth conditions: height suppressed, recently released, and previously tall (i.e., tall prior to the height increase of released willows). Released and previously tall willows exhibited high and similar vertical structure, but released willows were significantly lower in horizontal structure. Suppressed willows were significantly shorter and lower in horizontal cover than released or previously tall willows. Bird richness increased along a gradient from lowest in suppressed to highest in previously tall willows, but abundance and diversity were similar between released and previously tall willows, despite lower horizontal cover in the released condition. Common Yellowthroat (Geothlypis trichas) and Lincoln's Sparrow (Melospiza lincolnii) were found in all three growth conditions; however, Yellow Warbler (Dendroica petechia), Warbling Vireo (Vireo gilvus), Willow Flycatcher (Empidonax traillii), and Song Sparrow (Melospiza melodii) were present in released and previously tall willows only. Wilson's Warbler (Wilsonia pusilla) was found in previously tall willows only, appearing to specialize on tall, dense willows. The results of our a priori habitat models indicated that foliage height diversity was the primary driver of bird richness, abundance, and diversity. These results indicate that vertical structure was a more important driver of bird community variables than horizontal

Light-regulated leaf expansion in two Populus species: dependence on developmentally controlled ion transport.

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Stiles, Kari A; Van Volkenburgh, Elizabeth

2002-07-01

Leaf growth responses to light have been compared in two species of Populus, P. deltoides and P. trichocarpa. These species differ markedly in morphology, anatomy, and dependence on light during leaf expansion. Light stimulates the growth rate and acidification of cell walls in P. trichocarpa but not in P. deltoides, whereas leaves of P. deltoides maintain growth in the dark. Light-induced growth is promoted in P. deltoides when cells are provided 50-100 mM KCl. In both species, light initially depolarizes, then hyperpolarizes mesophyll plasma membranes. However, in the dark, the resting E(m) of mesophyll cells in P. deltoides, but not in P. trichocarpa, is relatively insensitive to decade changes in external [K+]. Results suggest that light-stimulated leaf growth depends on developmentally regulated cellular mechanisms controlling ion fluxes across the plasma membrane. These developmental differences underlie species-level differences in growth and physiological responses to the photoenvironment.

Near-ambient ozone concentrations reduce the vigor of Betula and Populus species in Finland.

Science.gov (United States)

Oksanen, Elina; Manninen, Sirkku; Vapaavuori, Elina; Holopainen, Toini

2009-12-01

In this review the main growth responses of Finnish birch (Betula pendula, B. pubescens) and aspen species (Populus tremula and P. tremuloides x P. tremula) are correlated with ozone exposure, indicated as the AOT40 value. Data are derived from 23 different laboratory, open-top chamber, and free-air fumigation experiments. Our results indicate that these tree species are sensitive to increasing ozone concentrations, though high intraspecific variation exists. The roots are the most vulnerable targets in both genera. These growth reductions, determined from trees grown under optimal nutrient and water supply, were generally accompanied by increased visible foliar injuries, carbon allocation toward defensive compounds, reduced carbohydrate contents of leaves, impaired photosynthesis processes, disturbances in stomatal function, and earlier autumn senescence. Because both genera have shown complex ozone defense and response mechanisms, which are modified by variable environmental conditions, a mechanistically based approach is necessary for accurate ozone risk assessment.

Cadmium accumulation in Salix in relation to cadmium concentration in the soil; Kadmiumhalten i Salix relaterad till kadmiumhalten i jorden. Studier av olika Salixkloners foermaaga att ta upp kadmium

Energy Technology Data Exchange (ETDEWEB)

Greger, M; Landberg, T [Stockholm Univ. (Sweden). Dept. of Botany

1996-05-01

It has earlier been shown that different clones of Salix accumulate cadmium to a different degree. Moreover, the distribution of cadmium within the plant also differs between clones. If these properties are stable, there will be possibilities to chose clones for different purposes. The aim with this investigation was to find out if the differences between clones were stable and persist even though the clones were collected from different fields. Furthermore, to find out if the differences depend on the soil status and the concentration of cadmium of different soil fractions. The cadmium concentration of stems on different level within a plant and at different age of stems were analysed. The concentration in bark and wood as well as in leaves were examined to increase the knowledge of cadmium distribution within the different clones. The cadmium concentration was always higher in the leaves than in the stems. The difference between leaf content and stem content was highest in those clones which had a high transport to the shoot. The contribution of cadmium to the soil by the leaf shed will therefore be high from the high accumulating and high transporting clones. The conclusions one can draw from this investigation are that the clones possess specific properties to accumulate and transport cadmium, and these properties are independent of where the clones are collected. The differences in cadmium concentration within one clone collected from different fields is therefore to be explained by environmental conditions, other than those studied in this investigation. This work indicates that these unknown environmental factors influence the cadmium accumulation of stems more than the soil conditions and the cadmium level of the soil. It is therefore possible to chose clones with desired properties of cadmium accumulation, while the level of cadmium uptake is determined by the field conditions. 19 refs, 17 figs, 9 tabs

Tree and shrub expansion over the past 34 years at the tree-line near Abisko, Sweden.

Science.gov (United States)

Rundqvist, Sara; Hedenås, Henrik; Sandström, Anneli; Emanuelsson, Urban; Eriksson, Håkan; Jonasson, Christer; Callaghan, Terry V

2011-09-01

Shrubs and trees are expected to expand in the sub-Arctic due to global warming. Our study was conducted in Abisko, sub-arctic Sweden. We recorded the change in coverage of shrub and tree species over a 32- to 34-year period, in three 50 x 50 m plots; in the alpine-tree-line ecotone. The cover of shrubs and trees (tree stems (> or =3.5 cm) were noted and positions determined. There has been a substantial increase of cover of shrubs and trees, particularly dwarf birch (Betula nana), and mountain birch (Betula pubescens ssp. czerepanovii), and an establishment of aspen (Populus tremula). The other species willows (Salix spp.), juniper (Juniperus communis), and rowan (Sorbus aucuparia) revealed inconsistent changes among the plots. Although this study was unable to identify the causes for the change in shrubs and small trees, they are consistent with anticipated changes due to climate change and reduced herbivory.

Effect of plants on the bioavailability of metals and other chemical properties of biosolids in a column study.

Science.gov (United States)

Huynh, Trang T; Laidlaw, W Scott; Singh, Balwant; Zhang, Hao; Baker, Alan J M

2012-10-01

The effects of metal-accumulating plants (Salix x reichardtii and Populus balsamifera) on the chemical properties and dynamics of metals in biosolids were investigated using different techniques including diffusive gradients in thin films (DGT), sequential extraction procedures and partitioning coefficient (K(d)). Plants could effectively extract Cd, Ni, and Zn and decreased dissolved organic carbon (DOC). The presence of plants increased the potential bioavailability of these metals, as assessed by an increase in the ratio of metal measured by DGT and metals in the solution. The plants affected the Cd, Ni, and Zn pools (soluble/exchangeable; Fe/Mn oxide and organic matter bound) characterised by sequential extraction and K(d) but did not reduce the total metals in either substrate. However, plants had no effect on Cu, presumably because of the effective buffering of available Cu by organic matter in both solution and solid phases. A high density of plant roots was associated with increased leaching of metals.

Effects of metal-contaminated soil on the performance of young trees growing in model ecosystems under field conditions

International Nuclear Information System (INIS)

Hermle, Sandra; Guenthardt-Goerg, Madeleine S.; Schulin, Rainer

2006-01-01

Young Populus tremula, Salix viminalis, Betula pendula and Picea abies trees were grown together in large open-top chambers. The treatments were: without or with (Cu/Zn/Cd/Pb = 640/3000/10/90 mg kg -1 ) metal contamination in the topsoil, irrigation pH 3.5 or 5.5, and acidic or calcareous subsoil. Growth, metal allocation to foliage and wood, as well as leaf gas exchange were measured. Biomass was reduced in P. tremula and B. pendula by the metal-contaminated topsoil relative to uncontaminated topsoil, whereas in P. tremula photosynthesis and transpiration were decreased. These effects were related to the elevated foliar Zn accumulation in P. tremula. S. viminalis showed a significant reduction in growth and an increased Zn and Cd accumulation on acidic vs. calcareous subsoil. Acidic irrigation produced only a few significant effects. P. abies showed the lowest metal uptake and no growth response to metal contamination. - Four tree species had different responses to metal treatments

Effects of progressive soil water deficit on growth, and physiological and biochemical responses of populus euphratica in arid area: a case study in China

International Nuclear Information System (INIS)

Yang, Y.; Chen, Y.; Li, W.; Zhu, C.

2015-01-01

The aim of this study was to investigate the responses of Populus euphratica seedlings under a short-term soil water deficit. To mimic natural conditions in which drought stress develops gradually, stress was imposed by subjecting plants to a gradual decrease of soil water content for a period of 21 d. We studied growth, physiological and biochemical responses to progressive soil water deficit of potted Populus euphratica seedlings at outdoors. Results showed that, in 6 d of water withholding, the soil moisture content decreased to a slight drought stress level, and it reached a severe drought stress level after 15 d of water withholding in July. In the process of soil water declining from saturated to severe drought levels, the increasing soil water deficit resulted in decreases in the height, stem base diameter, number of lateral branches. Leaf predawn water potential decreased after 15 d of withholding irrigation. After 21 d of withholding irrigation, actual photochemical efficiency of photosystem II (PSII) in light-adapted leaves and photochemical quenching coefficient decreased, respectively; the peroxidase activity, the content of chlorophyll a and chlorophyll b decreased. There were no significant changes in proline, malondialdehyde content, chlorophyll a/b value and superoxide dismutase activity. (author)

体外产气法研究沙柳混合发酵饲料对绵羊瘤胃内环境参数的影响%Effects of Salix Mixed Fermented Feed on Ruminal Environmental Parameters by in Vitro Gas Production Method

Institute of Scientific and Technical Information of China (English)

李满双; 薛树媛; 王超; 王莉梅; 郭天龙; 金海

2015-01-01

The current experiment was carried out to investigate the effects of Salix mixed fermented feed on ruminal environmental parameters by in vitro gas production method. According to the different proportion of Salix (36.44% and 67.08%), two groups of mixed fermentation feed were made, represented by FF1 and FF2 groups respectively. Each group was added the same number of compound bacteria preparation ( live number≥5×107 CFU/g). Gas production and gas production kinetic parameters in 96 h, and ruminal fermentation char-acteristic indexes in 24 h at different fermentation periods of 1, 3, 5, 7, 10, 12, 15, 22, 30, 45 and 60 days were determined, respectively. The results showed as follows:1) with the extension of fermentation time, ac-cumulative gas production in 96 h, digestible organic matter content and metabolizable energy were firstly de-creased and then increased. 2) The concentrations of volatile fatty acids and microbial protein were significantly increased ( P<0.05) , while pH, the concentrations of ammonia nitrogen and butyric acid, and acetic acid/pro-pionic acid were significantly decreased by Salix mixed fermentation feed ( P<0.05) . In conclusion, under in vitro culture condition, the two kinds of Salix mixed fermented feed with the supplemental proportion of Salix of 36.44% and 67.08% can effectively promote rumen microbial fermentation, raise energy utilization efficien-cy and increase the microbial protein synthesis in rumen, and the optimal supplemental proportion of Salix is 36.44% compared with 67.08%.%本试验旨在采用体外产气法研究沙柳混合发酵饲料对绵羊瘤胃内环境参数的影响。按沙柳不同添加量(36.44%和67.08%)调制成2组混合发酵饲料，分别用FF1组和FF2组表示，在各组中添加等量的复合菌剂(活菌数≥5×107 CFU/g)，考察发酵饲料在发酵1、3、5、7、10、12、15、22、30、45和60 d时，体外培养96 h的产气量、产气动力学参数和24 h�

Changes in photosynthesis, mesophyll conductance to CO{sub 2}, and isoprenoid emissions in Populus nigra plants exposed to excess nickel

Energy Technology Data Exchange (ETDEWEB)

Velikova, Violeta, E-mail: violet@obzor.bio21.bas.bg [Bulgarian Academy of Sciences, Acad. M. Popov Institute of Plant Physiology, Acad. G. Bonchev, Bl. 21, 1113 Sofia (Bulgaria); Tsonev, Tsonko [Bulgarian Academy of Sciences, Acad. M. Popov Institute of Plant Physiology, Acad. G. Bonchev, Bl. 21, 1113 Sofia (Bulgaria); Loreto, Francesco [Consiglio Nazionale delle Ricerche, Istituto per la Protezione delle Piante, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze (Italy); Centritto, Mauro [Consiglio Nazionale delle Ricerche, Istituto di Biologia Agroambientale e Forestale, 00015 Monterotondo Scalo (RM) (Italy)

2011-05-15

Poplar (Populus nigra) plants were grown hydroponically with 30 and 200 {mu}M Ni (Ni{sub 30} and Ni{sub 200}). Photosynthesis limitations and isoprenoid emissions were investigated in two leaf types (mature and developing). Ni stress significantly decreased photosynthesis, and this effect depended on the leaf Ni content, which was lower in mature than in developing leaves. The main limitations to photosynthesis were attributed to mesophyll conductance and metabolism impairment. In Ni-stressed developing leaves, isoprene emission was significantly stimulated. We attribute such stimulation to the lower chloroplastic [CO{sub 2}] than in control leaves. However chloroplastic [CO{sub 2}] did not control isoprene emission in mature leaves. Ni stress induced the emission of cis-{beta}-ocimene in mature leaves, and of linalool in both leaf types. Induced biosynthesis and emission of isoprenoids reveal the onset of antioxidant processes that may also contribute to reduce Ni stress, especially in mature poplar leaves. - Graphical abstract: Visible damage caused by Ni treatment. 1 - Ni{sub 0} (control plants); 2 - Ni{sub 200}; M = mature and D = developing Populus nigra leaves. Display Omitted Highlights: > We study the effect of Ni pollution on photosynthesis and isoprenoid emissions. > Ni stress significantly decreases photosynthesis. The main limitations are attributed to mesophyll conductance and metabolism impairment. > Constitutive isoprene emission was significantly stimulated in Ni-stressed leaves. Exposure to enhanced Ni concentration induces cis-beta-ocimene and linalool emissions. - The study reveals consequences of Ni stress on plant physiology, namely increasing diffusional limitation to photosynthesis and isoprenoid emissions.

Fungal colonization and decomposition of leaves and stems of Salix arctica on deglaciated moraines in high-Arctic Canada

Science.gov (United States)

Osono, Takashi; Matsuoka, Shunsuke; Hirose, Dai; Uchida, Masaki; Kanda, Hiroshi

2014-06-01

Fungal colonization, succession, and decomposition of leaves and stems of Salix arctica were studied to estimate the roles of fungi in the decomposition processes in the high Arctic. The samples were collected from five moraines with different periods of development since deglaciation to investigate the effects of ecosystem development on the decomposition processes during the primary succession. The total hyphal lengths and the length of darkly pigmented hyphae increased during decomposition of leaves and stems and were not varied with the moraines. Four fungal morphotaxa were frequently isolated from both leaves and stems. The frequencies of occurrence of two morphotaxa varied with the decay class of leaves and/or stems. The hyphal lengths and the frequencies of occurrence of fungal morphotaxa were positively or negatively correlated with the contents of organic chemical components and nutrients in leaves and stems, suggesting the roles of fungi in chemical changes in the field. Pure culture decomposition tests demonstrated that the fungal morphotaxa were cellulose decomposers. Our results suggest that fungi took part in the chemical changes in decomposing leaves and stems even under the harsh environment of the high Arctic.

Development of a method for testing the susceptibility of Salix alba to Erwinia salicis

Energy Technology Data Exchange (ETDEWEB)

Dingjan-Versteegh, A M; de Kam, M [Institute for Forestry and Urban Ecology, Wageningen (Netherlands)

1990-01-01

Salix is one of the faster growing tree species that has potential for biomass plantations in Europe. This potential, however, is limited by the occurrence of a vascular disease caused by the bacterium Erwinia salicis (Day) Chester. Selection and breeding of disease resistance is hampered by insufficient knowledge of the infection biology and ecology of the pathogen. The availability of specific antisera is of vital importance in the study of the infection biology and in monitoring bacterial populations inside the host. Therefore, one of the aims of the research was to improve the antisera. The composition of the soluble antigens of E. salicis was studied by enzyme-linked immunosorbent assay (ELISA), polyacrylamide gel electrophoresis (PAGE) and electro-immunoblotting. Antiserum prepared to whole cells of E. salicis mainly contains antibodies to bacterial surface antigens or to soluble antigens. ELISA demonstrated the presence of bacterial soluble antigens in leaves of diseased willow trees and also in leaves of willow shoots which were placed in a solution of bacterial soluble antigens. An inoculation experiment was carried out to ascertain if there is a statistically significant correlation between plant water potential and response to artificial inoculation with E. salicis. To elucidate the mechanisms involved in pathogenicity and virulence of E. salicis, attempts were made to isolate the plasmids of the bacterium, however, it appears that E. salicis does not have plasmids. In collaboration with Ch. Maceau (21), the E. salicis genome was isolated and a genomic library was constructed in E. coli. 28 refs., 10 figs., 4 tabs.

Black poplar-tree (Populus nigra L.) bark as an alternative indicator of urban air pollution by chemical elements

International Nuclear Information System (INIS)

Berlizov, A.N.; Malyuk, I.A.; Tryshyn, V.V.

2008-01-01

Capabilities of black poplar-tree (Populus nigra L.) bark as a biomonitor of atmospheric air pollution by chemical elements were tested against epiphytic lichens Xanthoria parietina (L.) and Physcia adscendens (Fr.). Concentrations of 40 macro and trace elements were determined using epicadmium and instrumental NAA. The data obtained were processed using non-parametric tests. A good correlation was found between concentrations of majority of elements in bark and lichens. On the accumulation capability bark turned out to be competitive with both lichens examined. The main inorganic components of black poplar-tree bark were revealed. A substrate influence on the concentrations of some elements in epiphytic lichens was established. An optimized procedure of bark pre-irradiation treatment was suggested. (author)

In-situ reduced silver nanoparticles on populus fiber and the catalytic application

Energy Technology Data Exchange (ETDEWEB)

Li, Miaomiao; Gong, Yumei, E-mail: ymgong@dlpu.edu.cn; Wang, Wenheng; Xu, Guangpeng; Liu, Yuanfa; Guo, Jing, E-mail: guojing8161@163.com

2017-02-01

Highlights: • A composite involved in in-situ chelating AgNPs on natural cellulose was prepared. • Polyamidoxime grafted from the cellulose adsorbed Ag+ which was reduced to AgNPs. • The composite exhibits excellent catalytic activity in reducing 4-nitrophenol. - Abstract: One kind of composites involved in silver nanoparticles (AgNPs) loading in-situ on natural populus fiber (PF) matrix was prepared by polyamidoxime (PAO) functionalized the cellulose fiber. In which PAO worked as trapping and stabilizing agents chelating silver ions and made it reduced in-situ to obtain AgNPs by borohydride at room temperature. The synthesized composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Moreover, the composites showed significant catalytic activity 1.87 s{sup −1} g{sup −1} and repeated usability more than 7 cycles in reducing 4-nitrophenol (4-NP) into 4-aminophenol (4-AP) detected by UV–vis spectrophotometer in aqueous solution due to the surface-enhanced immobility and large amount of AgNPs. The natural cellulose fiber provides a green platform to react and support other noble metals for wide catalytic reactions.

Widespread triploidy in Western North American aspen (Populus tremuloides.

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Karen E Mock

Full Text Available We document high rates of triploidy in aspen (Populus tremuloides across the western USA (up to 69% of genets, and ask whether the incidence of triploidy across the species range corresponds with latitude, glacial history (as has been documented in other species, climate, or regional variance in clone size. Using a combination of microsatellite genotyping, flow cytometry, and cytology, we demonstrate that triploidy is highest in unglaciated, drought-prone regions of North America, where the largest clone sizes have been reported for this species. While we cannot completely rule out a low incidence of undetected aneuploidy, tetraploidy or duplicated loci, our evidence suggests that these phenomena are unlikely to be significant contributors to our observed patterns. We suggest that the distribution of triploid aspen is due to a positive synergy between triploidy and ecological factors driving clonality. Although triploids are expected to have low fertility, they are hypothesized to be an evolutionary link to sexual tetraploidy. Thus, interactions between clonality and polyploidy may be a broadly important component of geographic speciation patterns in perennial plants. Further, cytotypes are expected to show physiological and structural differences which may influence susceptibility to ecological factors such as drought, and we suggest that cytotype may be a significant and previously overlooked factor in recent patterns of high aspen mortality in the southwestern portion of the species range. Finally, triploidy should be carefully considered as a source of variance in genomic and ecological studies of aspen, particularly in western U.S. landscapes.

A 34K SNP genotyping array for Populus trichocarpa: design, application to the study of natural populations and transferability to other Populus species.

Science.gov (United States)

Geraldes, A; Difazio, S P; Slavov, G T; Ranjan, P; Muchero, W; Hannemann, J; Gunter, L E; Wymore, A M; Grassa, C J; Farzaneh, N; Porth, I; McKown, A D; Skyba, O; Li, E; Fujita, M; Klápště, J; Martin, J; Schackwitz, W; Pennacchio, C; Rokhsar, D; Friedmann, M C; Wasteneys, G O; Guy, R D; El-Kassaby, Y A; Mansfield, S D; Cronk, Q C B; Ehlting, J; Douglas, C J; Tuskan, G A

2013-03-01

Genetic mapping of quantitative traits requires genotypic data for large numbers of markers in many individuals. For such studies, the use of large single nucleotide polymorphism (SNP) genotyping arrays still offers the most cost-effective solution. Herein we report on the design and performance of a SNP genotyping array for Populus trichocarpa (black cottonwood). This genotyping array was designed with SNPs pre-ascertained in 34 wild accessions covering most of the species latitudinal range. We adopted a candidate gene approach to the array design that resulted in the selection of 34 131 SNPs, the majority of which are located in, or within 2 kb of, 3543 candidate genes. A subset of the SNPs on the array (539) was selected based on patterns of variation among the SNP discovery accessions. We show that more than 95% of the loci produce high quality genotypes and that the genotyping error rate for these is likely below 2%. We demonstrate that even among small numbers of samples (n = 10) from local populations over 84% of loci are polymorphic. We also tested the applicability of the array to other species in the genus and found that the number of polymorphic loci decreases rapidly with genetic distance, with the largest numbers detected in other species in section Tacamahaca. Finally, we provide evidence for the utility of the array to address evolutionary questions such as intraspecific studies of genetic differentiation, species assignment and the detection of natural hybrids. © 2013 Blackwell Publishing Ltd.

Unexpected ancestry of Populus seedlings from a hybrid zone implies a large role for postzygotic selection in the maintenance of species.

Science.gov (United States)

Lindtke, Dorothea; Gompert, Zachariah; Lexer, Christian; Buerkle, C Alex

2014-09-01

In the context of potential interspecific gene flow, the integrity of species will be maintained by reproductive barriers that reduce genetic exchange, including traits associated with prezygotic isolation or poor performance of hybrids. Hybrid zones can be used to study the importance of different reproductive barriers, particularly when both parental species and hybrids occur in close spatial proximity. We investigated the importance of barriers to gene flow that act early vs. late in the life cycle of European Populus by quantifying the prevalence of homospecific and hybrid matings within a mosaic hybrid zone. We obtained genotypic data for 11 976 loci from progeny and their maternal parents and constructed a Bayesian model to estimate individual admixture proportions and hybrid classes for sampled trees and for the unsampled pollen parent. Matings that included one or two hybrid parents were common, resulting in admixture proportions of progeny that spanned the whole range of potential ancestries between the two parental species. This result contrasts strongly with the distribution of admixture proportions in adult trees, where intermediate hybrids and each of the parental species are separated into three discrete ancestry clusters. The existence of the full range of hybrids in seedlings is consistent with weak reproductive isolation early in the life cycle of Populus. Instead, a considerable amount of selection must take place between the seedling stage and maturity to remove many hybrid seedlings. Our results highlight that high hybridization rates and appreciable hybrid fitness do not necessarily conflict with the maintenance of species integrity. © 2014 John Wiley & Sons Ltd.

Group Self-Definitions and Religious Collectivities in the 16th Book of the Theodosian Code. Notes on the Term coetus (with a Preliminary Analysis of populus

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Alessandro Saggioro

2015-06-01

Full Text Available This essay starts from the well-known definition of populus as well as it appears in some Cicero’s works and aims at analyze the religious significance of coetus, a term strictly connected with the first, at least focusing on the 16th book of the Theodosian Code. This article intends to cast light some transformations and representations of religious groups between Constantinian and Post-Constantinian ages.

Salix alba attenuated oxidative stress in the heart and kidney of hypercholesterolemic rabbits

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Narges Amel Zabihi

2017-12-01

Full Text Available Objective: Oxidative stress plays a critical role in the development of hypercholesterolemia-induced complications. This study evaluated the effects of aspirin and Salix alba hydroethanolic extract on oxidative stress in the heart and kidney of hypercholesterolemic rabbits. Materials and Methods: The antioxidant activity, as well as total phenolic and salicin content of S. alba (Sa extract were assessed by DPPH radical scavenging activity, Folin-Ciocalteu and HPLC methods, respectively. Animals were divided into two groups of control (fed with normal chow, and HD (fed with high cholesterol diet for 6 weeks. Then, hypercholesterolemic animals allocated to the following treatment groups: CHO (received HD, Sa extract (HD plus extract 60 and 120 mg/kg, and aspirin (HD plus aspirin 120 mg/kg and received the treatments on a daily basis for 6 weeks. MDA, GSH, and nitrite concentrations as well as the activities of SOD and CAT were evaluated in cardiac and kidney tissues. Results: The scavenging activity, total phenolic content and salicin were 19.1 µg/ml (IC50, 153.75 ± 3.6 mg of gallic acid/g, and 18.03 µg/mg, respectively. In comparison to CHO group, MDA levels were diminished in Sa and ASA groups but GSH levels were improved. NO metabolites increased in the heart of Sa 120 mg/kg group and in the kidney of all Sa and ASA treated groups. SOD activity increased only in the heart of Sa groups and in the kidney of Sa and ASA groups. CAT activity increased in the heart and kidney tissues of all Sa and ASA treated groups. Conclusion: The results showed S. alba extract improved redox homeostasis in heart and kidney tissues of hypercholesterolemic rabbits. The extract antioxidant property may be related to its phenolic content.

Genome-wide identification and characterization of WRKY gene family in Salix suchowensis.

Science.gov (United States)

Bi, Changwei; Xu, Yiqing; Ye, Qiaolin; Yin, Tongming; Ye, Ning

2016-01-01

WRKY proteins are the zinc finger transcription factors that were first identified in plants. They can specifically interact with the W-box, which can be found in the promoter region of a large number of plant target genes, to regulate the expressions of downstream target genes. They also participate in diverse physiological and growing processes in plants. Prior to this study, a plenty of WRKY genes have been identified and characterized in herbaceous species, but there is no large-scale study of WRKY genes in willow. With the whole genome sequencing of Salix suchowensis, we have the opportunity to conduct the genome-wide research for willow WRKY gene family. In this study, we identified 85 WRKY genes in the willow genome and renamed them from SsWRKY1 to SsWRKY85 on the basis of their specific distributions on chromosomes. Due to their diverse structural features, the 85 willow WRKY genes could be further classified into three main groups (group I-III), with five subgroups (IIa-IIe) in group II. With the multiple sequence alignment and the manual search, we found three variations of the WRKYGQK heptapeptide: WRKYGRK, WKKYGQK and WRKYGKK, and four variations of the normal zinc finger motif, which might execute some new biological functions. In addition, the SsWRKY genes from the same subgroup share the similar exon-intron structures and conserved motif domains. Further studies of SsWRKY genes revealed that segmental duplication events (SDs) played a more prominent role in the expansion of SsWRKY genes. Distinct expression profiles of SsWRKY genes with RNA sequencing data revealed that diverse expression patterns among five tissues, including tender roots, young leaves, vegetative buds, non-lignified stems and barks. With the analyses of WRKY gene family in willow, it is not only beneficial to complete the functional and annotation information of WRKY genes family in woody plants, but also provide important references to investigate the expansion and evolution of

A multi-adaptive framework for the crop choice in paludicultural cropping systems

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Nicola Silvestri

2017-03-01

Full Text Available The conventional cultivation of drained peatland causes peat oxidation, soil subsidence, nutrient loss, increasing greenhouse gas emissions and biodiversity reduction. Paludiculture has been identified as an alternative management strategy consisting in the cultivation of biomass on wet and rewetted peatlands. This strategy can save these habitats and restore the ecosystem services provided by the peatlands both on the local and global scale. This paper illustrates the most important features to optimise the crop choice phase which is the crucial point for the success of paludiculture systems. A multi-adaptive framework was proposed. It was based on four points that should be checked to identify suitable crops for paludicultural cropping system: biological traits, biomass production, attitude to cultivation and biomass quality. The main agronomic implications were explored with the help of some results from a plurennial open-field experimentation carried out in a paludicultural system set up in the Massaciuccoli Lake Basin (Tuscany, Italy and a complete example of the method application was provided. The tested crops were Arundo donax L., Miscanthus×giganteus Greef et Deuter, Phragmites australis L., Populus×canadensis Moench. and Salix alba L. The results showed a different level of suitability ascribable to the different plant species proving that the proposed framework can discriminate the behaviour of tested crops. Phragmites australis L. was the most suitable crop whereas Populus×canadensis Moench and Miscanthus×giganteus Greef et Deuter (in the case of biogas conversion occupied the last positions in the ranking.

TLC determination of some flavanones in the buds of different genus Populus species and hybrids

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Pobłocka-Olech Loretta

2018-06-01

Full Text Available Flavonoids in the buds of eight Populus species and hybrids were detected and compared with the aid of an optimized TLC method. Separation of 17 flavonoid aglycones belonging to different groups, namely, flavones, flavonols, flavanones and flavanonols, previously described as constituents of poplar buds, was performed on silica gel plates using a hexane/ethyl acetate/formic acid (60:40:1.3, V/V/V mixture as the mobile phase. Pinocembrin and pinostrobin were found in the majority of analyzed poplar buds. For quantitative analysis of both compounds, two TLC evaluation modes, densitometric and videodensitometric, were compared and the established methods were validated. Concentrations of flavanones in some extracts differed slightly or significantly due to the analyzed plant matrix complexity and the TLC evaluation mode applied. Poplar buds rich in flavanones originated from P. × canadensis ‘Robusta’ (1.82 and 2.23 g per 100 g, resp. and P. balsamifera (1.17 and 2.24 g per 100 g, resp..

Stem respiration of Populus species in the third year of free-air CO2 enrichment.

Science.gov (United States)

Gielen, Birgit; Scarascia-Mugnozza, Giuseppe; Ceulemans, Reinhart

2003-04-01

Carbon cycling in ecosystems, and especially in forests, is intensively studied to predict the effects of global climate change, and the role which forests may play in 'changing climate change'. One of the questions is whether the carbon balance of forests will be affected by increasing atmospheric CO2 concentrations. Regarding this question, effects of elevated [CO2] on woody-tissue respiration have frequently been neglected. Stem respiration of three Populus species (P. alba L. (Clone 2AS-11), P. nigra L. (Clone Jean Pourtet), and P. x euramericana (Clone I-214)) was measured in a managed, high-density forest plantation exposed to free-air CO2 enrichment (POPFACE). During the period of measurements, in May of the third year, stem respiration rates were not affected by the FACE treatment. Moreover, FACE did not influence the relationships between respiration rate and both stem temperature and relative growth rate. The results were supported by the reported absence of a FACE-effect on growth and stem wood density.

Organization and post-transcriptional processing of the psb B operon from chloroplasts of Populus deltoides.

Science.gov (United States)

Dixit, R; Trivedi, P K; Nath, P; Sane, P V

1999-09-01

Chloroplast genes are typically organized into polycistronic transcription units that give rise to complex sets of mono- and oligo-cistronic overlapping RNAs through a series of processing steps. The psbB operon contains genes for the PSII (psbB, psbT, psbH) and cytochrome b(6)f (petB and petD) complexes which are needed in different amounts during chloroplast biogenesis. The functional significance of gene organization in this polycistronic unit, containing information for two different complexes, is not known and is of interest. To determine the organization and expression of these complexes, studies have been carried out on crop plants by different groups, but not much information is known about trees. We present the nucleotide sequences of PSII genes and RNA profiles of the genes located in the psbB operon from Populus deltoides, a tree species. Although the gene organization of this operon in P. deltoides is similar to that in other species, a few variations have been observed in the processing scheme.

Particle size distribution of ashes and the behaviour of metals when firing Salix in a circulating fluidized bed boiler (CFB); Askans partikelfraktionsfoerdelning och metallernas beteende vid eldning av Salix i en CFB-panna

Energy Technology Data Exchange (ETDEWEB)

Sfiris, G; Johansson, A [Vattenfall Utveckling AB, Stockholm (Sweden); Valmari, T; Kauppinen, E; Pyykoenen, J; Lyyraenen, J [VTT Technical Research Centre of Finland, Espoo (Finland)

1999-07-01

This project is part of the Ash Recovery Programme aimed at establishing the environmental, technical and financial preconditions for returning wood ash to the forest. The programme is funded jointly by NUTEK, Sydkraft and Vattenfall. This report summarises the results of the experimental and modelling work to study the behaviour of the metals (especially Cd and K), after burning Salix in a 3-12 MW Circulating Fluidized Bed (CFB) boiler. The purpose of the study was to determine, using the experimental data, where cadmium and potassium condense, on what size particles they condense, and the decisive parameters governing these processes. Measurements of the fly ash particle size distribution carried out with a Berner Low Pressure Impactor (BLPI), coupled to a pre-cyclone. Samples were collected from three points: in the convection path at 650 deg C, after the convection path but before the secondary cyclone (160 deg C), and after the bag house (150 deg C). Wet chemical sampling was made for Cd, K, Zn and Pb, with three types of sampling equipment: collection of both particles and gas, collection of particles only, and analysis of the gas phase only. Analysis was made of samples from two places in the convection path (650 deg C and 250 deg C). Samples of bed material, bottom ash and fly ash have been subjected to scanning electron microscopy (SEM), and in addition a few fly ash particles, sampled after the convection path, were subjected to energy dispersive X-ray analysis (EDX). Based on experimental results, modelling work was carried out with an equilibrium model and with a general aerosol computer model ABC (Aerosol Behaviour in Combustion)

Latitudinal variation in cold hardiness in introduced Tamarix and native Populus

Science.gov (United States)

Friedman, Jonathan M.; Roelle, James E.; Gaskin, John F.; Pepper, Alan E.; Manhart, James R.

2008-01-01

To investigate the evolution of clinal variation in an invasive plant, we compared cold hardiness in the introduced saltcedar (Tamarix ramosissima, Tamarix chinensis, and hybrids) and the native plains cottonwood (Populus deltoidessubsp. monilifera). In a shadehouse in Colorado (41°N), we grew plants collected along a latitudinal gradient in the central United States (29–48°N). On 17 occasions between September 2005 and June 2006, we determined killing temperatures using freeze-induced electrolyte leakage and direct observation. In midwinter, cottonwood survived cooling to −70°C, while saltcedar was killed at −33 to −47°C. Frost sensitivity, therefore, may limit northward expansion of saltcedar in North America. Both species demonstrated inherited latitudinal variation in cold hardiness. For example, from September through January killing temperatures for saltcedar from 29.18°N were 5–21°C higher than those for saltcedar from 47.60°N, and on September 26 and October 11, killing temperatures for cottonwood from 33.06°N were >43°C higher than those for cottonwood from 47.60°N. Analysis of nine microsatellite loci showed that southern saltcedars are more closely related to T. chinensis while northern plants are more closely related to T. ramosissima. Hybridization may have introduced the genetic variability necessary for rapid evolution of the cline in saltcedar cold hardiness.

parámetros en híbridos de populus

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O. S. Vallejos-Barra

2007-01-01

Full Text Available La variable diámetro a la altura del pecho, medido a 1.3 m desde el suelo (DAP es lognormal si log(DAP-θ se distribuye normalmente. Para simplificar el ajuste de esta función de densidad de probabilidad (fdp se supone que el parámetro de localización (θ es cero en híbridos de Populus; sin embargo, en algunos casos esta simplificación no asegura el mejor ajuste de la fdp, incidiendo en la representación de la estructura horizontal de los híbridos. El objetivo de la investigación fue calcular el parámetro θ que proporcione el mejor ajuste de la fdp lognormal del DAP en los híbridos I-488 e I-63/51. Para este cálculo se utilizó un algoritmo de búsqueda binaria, que minimizó el estadístico Dn de la prueba de Kolmogorov-Smirnov. 38 % de las parcelas presentó un parámetro θ distinto de cero, originando una mejoría del valor de probabilidad (P entre 0.02 y 55.4 %. Se hizo un análisis de varianza no paramétrico de la variable “√n * Dn”, ya que la variable original y múltiples transformaciones no permitieron aceptar los supuestos del análisis paramétrico. El tipo de ajuste presentó diferencias estadísticas altamente significativas con un valor de 17.1 (P0.800 y las edades un valor de 11.2 (P>0.260.

Root anatomy and element distribution vary between two Salix caprea isolates with different Cd accumulation capacities

International Nuclear Information System (INIS)

Vaculík, Marek; Konlechner, Cornelia; Langer, Ingrid; Adlassnig, Wolfram; Puschenreiter, Markus; Lux, Alexander; Hauser, Marie-Theres

2012-01-01

The understanding of the influence of toxic elements on root anatomy and element distribution is still limited. This study describes anatomical responses, metal accumulation and element distribution of rooted cuttings of Salix caprea after exposure to Cd and/or Zn. Differences in the development of apoplastic barriers and tissue organization in roots between two distinct S. caprea isolates with divergent Cd uptake and accumulation capacities in leaves might reflect an adaptive predisposition based on different natural origins. Energy-dispersive X-ray spectroscopy (EDX) revealed that Cd and Zn interfered with the distribution of elements in a tissue- and isolate-specific manner. Zinc, Ca, Mg, Na and Si were enriched in the peripheral bark, K and S in the phloem and Cd in both vascular tissues. Si levels were lower in the superior Cd translocator. Since the cuttings originated from stocks isolated from polluted and unpolluted sites we probably uncovered different strategies against toxic elements. - Highlights: ► We describe responses in roots of S. caprea exposed to Cd and Zn. ► Apoplastic barrier development varied among isolates from differently polluted sites. ► EDX analyses revealed variations of element distributions in root tissues. ► Si weight% was lower in the isolate with a higher Cd translocation capacity. ► S. caprea isolates possessed different strategies to respond to Cd and Zn. - S. caprea altered element distribution and translocation, apoplastic barrier development and root anatomy upon Cd and/or Zn exposure.

Neurospora tetrasperma crosses heterozygous for hybrid ...

Indian Academy of Sciences (India)

2017-02-10

nucleus stage that follows meiosis and a post-meiotic mitosis, and the ascospores that form in eight-spored asci are usually homokaryotic. We had previously created novel TNt strains by introgressing four Neurospora crassa ...

Neurospora tetrasperma crosses heterozygous for hybrid

Indian Academy of Sciences (India)

nucleus stage that follows meiosis and apost-meiotic mitosis, and the ascospores that form in eight-spored asci are usually homokaryotic. We had previouslycreated novel TNt strains by introgressing four Neurospora crassa insertional ...

Salix polaris growth responses to active layer detachment and solifluction processes in High Arctic.

Science.gov (United States)

Siekacz, Liliana

2015-04-01

The work is dedicated to demonstrate the potential of Salix polaris grow properties in the dendrogemorphologic image, analyzing periglacially induced slope processes in the high Arctic.. Observed anatomical and morphological plants responses to solifluction and active layer detachment processes are presented qualitatively and quantitatively as a summary of presented features frequency. The results are discussed against the background of the other research results in this field. The investigations was performed in Ebba valley, in the vicinity of Petunia Bay, northernmost part of Billefjorden in central Spitsbergen (Svalbard). Environmental conditions are characterized by annual precipitation sum lower than 200 mm (Hagen et al.,1993) and average summer temperature of about 5°C, with maximum daily temperatures rarely exceeding 10°C (Rachlewicz, 2009). Collected shrub material was prepared according to the methods presented by Schweingruber and Poschlod (2005). Thin (approx. 15-20μm) sections of the whole cross-section were prepared with a sledge microtome, stained with Safranine and Astra blue and finally permanently fixed on microslides with Canada balsam and dried. Snapshots were taken partially for each cross-section with digital camera (ColorView III, Olympus) connected to a microscope (Olympus BX41) and merged into one, high resolution image. After all, ring widths were measured in 3-4 radii in every single cross-section using ImageJ software. Analyzed plants revealed extremely harsh environmental conditions of their growth. Buchwał et al. (2013) provided quantitative data concerning missing rings and partially missing rings in shrubs growing on Ebba valley floor. Mean ring width at the level of 79μm represents one of the smallest values of yearly growth ever noted. The share of missing rings and partially missing rings was 11,2% and 13,6% respectively. Plants growing on Ebba valley slope indicate almost twice smaller values of ring width (41μm), and higher

Qualitative variation in proanthocyanidin composition of Populus species and hybrids: genetics is the key.

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Scioneaux, Ashley N; Schmidt, Michael A; Moore, Melissa A; Lindroth, Richard L; Wooley, Stuart C; Hagerman, Ann E

2011-01-01

The literature on proanthocyanidins (tannins) in ecological systems is dominated by quantitative studies. Despite evidence that the qualitative characteristics (subunit type, polymer chain length) of these complex polyphenolics are important determinants of biological activity, little is known about genetic and environmental controls on the type of proanthocyanidins produced by plants. We tested the hypothesis that genetics, season, developmental stage, and environment determine proanthocyanidin qualitative characteristics by using four Populus "cross types" (narrowleaf [P. angustifolia], Fremont [P. fremontii], F1 hybrids, and backcrosses to narrowleaf). We used thiolysis and HPLC analysis to characterize the proanthocyanidins, and found that genetics strongly control composition. The narrowleaf plants accumulate mixed procyanidin/prodelphinidins with average composition epicatechin(11)-epigallocatechin(8)-catechin(2)-catechin((terminal)). Backcross genotypes produce mixed procyanidin/prodelphinidins similar to narrowleaf, while Fremont makes procyanidin dimers, and the F1 plants contain procyanidin heptamers. Less striking effects were noted for genotype × environment, while season and developmental zone had little effect on proanthocyanidin composition or chain length. We discuss the metabolic and ecological consequences of differences in condensed tannin qualitative traits.

Urbanization-related changes in European aspen (Populus tremula L.): Leaf traits and litter decomposition

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Nikula, Suvi; Vapaavuori, Elina; Manninen, Sirkku

2010-01-01

We investigated foliar and litter responses of European aspen (Populus tremula L.) to urbanization, including factors such as increased temperature, moisture stress and nitrogen (N) deposition. Leaf samples were collected in 2006-2008 from three urban and three rural forest stands in the Helsinki Metropolitan Area, southern Finland, and reciprocal litter transplantations were established between urban and rural sites. Urban leaves exhibited a higher amount of epicuticular waxes and N concentration, and a lower C:N ratio than rural ones, but there was no difference in specific leaf area. Urban litter had a slightly higher N concentration, lower concentrations of lignin and total phenolics, and was more palatable to a macrofaunal decomposer. Moreover, litter decay was faster at the urban site and for urban litter. Urbanization thus resulted in foliar acclimatization in terms of increased amount of epicuticular waxes, as well as in accelerated decomposition of the N-richer leaf litter. - Urbanization can modify leaf traits of aspen and accelerate litter decomposition through changes in litter traits as well as in environmental conditions at the decomposition site.

Microstructural and Topochemical Characterization of Thermally Modified Poplar (Populus cathayaha Cell Wall

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Zhe Ling

2015-11-01

Full Text Available Although many studies have been conducted on the wood property and chemical changes caused by thermal modification, little has been reported on the microstructural and topochemical changes occurring in the cell wall during heat treatment. In this study, poplar (Populus cathayaha was treated within a temperature range from 180 to 220 °C for 4 h. Chemical analyses by Fourier transform infrared spectroscopy (FTIR and nuclear magnetic resonance (NMR indicated that heat treatment resulted in deacetylation of hemicelluloses and cleavage of lignin chains, thus generating new carbonyl and phenolic linkages. Transformation of matrix substances contributed to microstructural changes that appeared in clearly distorted and collapsed fiber and vessel walls along with the delamination of compound middle lamella (CML and secondary walls (S, which showed a reduced capability to resist deformation. It was also observed by fluorescence microscopy (FM and scanning electron microscope coupled with energy dispersive X-ray analysis (SEM-EDXA that the concentration of lignin increased, probably because of the degradation of hemicelluloses and the generation of new carbonyl groups. These results on cell wall microstructure and topochemistry can help explain the altered wood properties revealed by dynamic mechanical analysis (DMA and equilibrium moisture content (EMC testing after heat treatment.

Thermo-mechanical Densification of Populus tomentosa var. tomentosa with Low Moisture Content

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Dengyun Tu

2014-05-01

Full Text Available This study used thermo-mechanical densification technology to compress low-moisture content (3~5% rapid-growth Populus tomentosa var. tomentosa trees to produce specimens with a low-compression ratio (small volume loss and a uniform density profile and desirable properties. Furthermore, the densified specimens were subjected to post-heat treatment at 180, 190, and 200 °C for 2, 3, and 4 h, respectively. Microscopic examination was performed to observe the changes that occurred in the wood vessels after densification. To determine the influence of post-heat treatment on the set recovery, the specimens were subjected to eight cycles of soaking and drying in 20 °C water and two cycles in boiling water. The density profile tendencies of the densified specimens were in accord with undensified specimens. Microscopic observation revealed that the deformations present in the densified wood resulted from the viscous buckling of cell walls without fracture. The volume of the void areas in the specimens decreased uniformly. Post-heat treatment can decrease compressive deformation, especially when applied at 200 °C for 4 h. After two boiling water cycles of soaking and drying, the densified wood still had a certain set recovery. Therefore, densified wood should be used sparingly in high temperature and high humidity environments.

Abnormal meiosis in an intersectional allotriploid of Populus L. and segregation of ploidy levels in 2x × 3x progeny.

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Jun Wang

Full Text Available Triploid plants are usually highly aborted owing to unbalanced meiotic chromosome segregation, but limited viable gametes can participate in the transition to different ploidy levels. In this study, numerous meiotic abnormalities were found with high frequency in an intersectional allotriploid poplar (Populus alba × P. berolinensis 'Yinzhong', including univalents, precocious chromosome migration, lagging chromosomes, chromosome bridges, micronuclei, and precocious cytokinesis, indicating high genetic imbalance in this allotriploid. Some micronuclei trigger mini-spindle formation in metaphase II and participate in cytokinesis to form polyads with microcytes. Unbalanced chromosome segregation and chromosome elimination resulted in the formation of microspores with aneuploid chromosome sets. Fusion of sister nuclei occurs in microsporocytes with precocious cytokinesis, which could form second meiotic division restitution (SDR-type gametes. However, SDR-type gametes likely contain incomplete chromosome sets due to unbalanced segregation of homologous chromosomes during the first meiotic division in triploids. Misorientation of spindles during the second meiotic division, such as fused and tripolar spindles with low frequency, could result in the formation of first meiotic division restitution (FDR-type unreduced gametes, which most likely contain three complete chromosome sets. Although 'Yinzhong' yields 88.7% stainable pollen grains with wide diameter variation from 23.9 to 61.3 μm, the pollen viability is poor (2.78% ± 0.38. A cross of 'Yinzhong' pollen with a diploid female clone produced progeny with extensive segregation of ploidy levels, including 29 diploids, 18 triploids, 4 tetraploids, and 48 aneuploids, suggesting the formation of viable aneuploidy and unreduced pollen in 'Yinzhong'. Individuals with different chromosome compositions are potential to analyze chromosomal function and to integrate the chromosomal dosage variation into

Association of Pinus banksiana Lamb. and Populus tremuloides Michx. seedling fine roots with Sistotrema brinkmannii (Bres.) J. Erikss. (Basidiomycotina).

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Potvin, Lynette R; Richter, Dana L; Jurgensen, Martin F; Dumroese, R Kasten

2012-11-01

Sistotrema brinkmannii (Bres.) J. Erikss. (Basidiomycotina, Hydanaceae), commonly regarded as a wood decay fungus, was consistently isolated from bareroot nursery Pinus banksiana Lamb. seedlings. S. brinkmannii was found in ectomycorrhizae formed by Thelephora terrestris Ehrh., Laccaria laccata (Scop.) Cooke, and Suillus luteus (L.) Roussel. In pure culture combinations with sterile P. banksiana and Populus tremuloides Michx. seedlings, S. brinkmannii colonized root cortical cells while not killing seedlings. Colonization by S. brinkmannii appeared to be intracellular but typical endo- or ectomycorrhizae were not formed. The fungus did not decay roots, although it was shown to produce cellulase in enzyme tests. Results suggest a unique association between S. brinkmannii and seedling roots that is neither mycorrhizal nor detrimental; its exact function remains to be elucidated.

Water relations and gas exchange in poplar and willow under water stress and elevated atmospheric CO2.

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Johnson, Jon D; Tognetti, Roberto; Paris, Piero

2002-05-01

Predictions of shifts in rainfall patterns as atmospheric [CO2] increases could impact the growth of fast growing trees such as Populus spp. and Salix spp. and the interaction between elevated CO2 and water stress in these species is unknown. The objectives of this study were to characterize the responses to elevated CO2 and water stress in these two species, and to determine if elevated CO2 mitigated drought stress effects. Gas exchange, water potential components, whole plant transpiration and growth response to soil drying and recovery were assessed in hybrid poplar (clone 53-246) and willow (Salix sagitta) rooted cuttings growing in either ambient (350 &mgr;mol mol-1) or elevated (700 &mgr;mol mol-1) atmospheric CO2 concentration ([CO2]). Predawn water potential decreased with increasing water stress while midday water potentials remained unchanged (isohydric response). Turgor potentials at both predawn and midday increased in elevated [CO2], indicative of osmotic adjustment. Gas exchange was reduced by water stress while elevated [CO2] increased photosynthetic rates, reduced leaf conductance and nearly doubled instantaneous transpiration efficiency in both species. Dark respiration decreased in elevated [CO2] and water stress reduced Rd in the trees growing in ambient [CO2]. Willow had 56% lower whole plant hydraulic conductivity than poplar, and showed a 14% increase in elevated [CO2] while poplar was unresponsive. The physiological responses exhibited by poplar and willow to elevated [CO2] and water stress, singly, suggest that these species respond like other tree species. The interaction of [CO2] and water stress suggests that elevated [CO2] did mitigate the effects of water stress in willow, but not in poplar.

Leaf degradation of Salix humboldtiana Willd: (Salicaceae and invertebrate colonization in a subtropical lake (Brazil Degradação foliar de Salix humboldtiana Willd: (Salicaceae e colonização por invertebrados em um lago subtropical (Brasil

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Franko Telöken

2011-03-01

Full Text Available AIM: To evaluate leaf degradation and invertebrate colonization of Salix humboldtiana Willd. in a subtropical shallow lake on the coastal plain of Rio Grande do Sul, Brazil; METHODS: Litter bags containing 6.85 g of leaves were incubated in the superficial layer of sediment in the littoral region for 1, 4, 7, 14, 32, 47 and 71 days; RESULTS: After 71 days, a loss of 51% of the initial leaf weight was observed (k = 0.0100 d-1. We estimated that it would take 300 days to lose 95% of the initial weight. A total of 16040 organisms and 35 taxa were identified. Caenidae (25.9%, Oligochaeta (19%, Ostracoda (13.8%, Hydracarina (9.8%, Tanypodinae (9.7% and Coenagrionidae (7.7% were the most highly represented taxa. We observed increases in density, richness and diversity of taxa over time, with a stabilizing trend noted in the taxa diversity. Regarding the functional trophic groups (FTGs, gathering-collectors accounted for 57.6% of the community, while predators (25%, scrapers (15.8%, filtering-collectors (0.88% and shredders (0.73% were also represented. The diversity and evenness of the FTGs had stabilized by day 14; CONCLUSIONS: S. humboldtiana detritus provides a favorable habitat for a sufficient duration to support a high density and diversity of aquatic invertebrates. The small percentage of shredders indicates the minor influence of the invertebrate community on the rate of detrital degradation. The main contribution of invertebrates to detrital processing comes from the consumption of fine particulate organic matter by gathering-collectors.OBJETIVOS: Avaliar a degradação foliar de Salix humboldtiana Willd. e a colonização pela comunidade de invertebrados aquáticos em um lago raso subtropical, planície costeira do Rio Grande do Sul, Brasil; MÉTODOS: Bolsas de decomposição contendo 6,85 g de folhas foram incubadas na região litorânea, na superfície do sedimento, e retiradas após 1, 4, 7, 14, 32, 47 e 71 dias de decomposi

Sex-specific responses of Populus deltoides to defoliation

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Li Shuxin

2017-12-01

Full Text Available There has been an increasing interest in understanding the differential effects of sexual dimorphism on plant stress responses. However, there is no clear pattern in the responses of the sexes to defoliation. In this study, the effects of different severity of artificial defoliation on biomass production, total nonstructural carbohydrate (NSC concentration, and photosynthetic rate (PN of male and female Populus deltoides were examined. We used half and full defoliation to observe the differences between the sexes in three harvest dates (1 week, 4 weeks, and 8 weeks after treatments. We hypothesized that female and male P. deltoides compared with an undefoliated control would have compensatory growth in response to defoliation treatments. Results showed that half and full defoliation reduced the growth of both sexes. Following half defoliation, root growth was reduced, especially in males, at T2 (4 weeks after defoliation and T3 (8 weeks after defoliation, while males showed an increase in height increment under the half defoliation compared with the nondefoliation treatments. By contrast, females were more negatively affected by defoliation than males in terms of biomass after 8 weeks. One week after defoliation, PN increased significantly in females and males under half defoliation (+30%, +32%, respectively and full defoliation (+58%, +56%, respectively. However, 8 weeks after defoliation, there was little difference in PN between defoliated and undefoliated female cuttings. Increases in stomatal conductance (gs and leaf nitrogen were observed under fully defoliated female and male cuttings. Moreover, males had less NSC concentrations following half defoliation compared with females. Our results indicate that leaf compensatory growth in male cuttings of P. deltoides was maintained by obtaining greater photosynthetic capacity, higher leaf nitrogen, and lower NSC concentration following half and full defoliation. Our results highlight that

Litter Quality of Populus Species as Affected by Free-Air CO2 Enrichment and N-Fertilization

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Vermue, E.; Buurman, P.; Hoosbeek, M.R.

2010-01-01

The effect of elevated CO 2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM) was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter samples. Litter of P. euramerica was clearly different from that of P. nigra and P. alba. The latter two had higher contents of proteins, polysaccharides, and cutin/cutan, while the former had higher contents of phenols and benzofurans/pyrans. The difference between replications was at least as large as the effect of treatments, so that no systematic chemical changes were attributable to CO 2 effect or N-fertilization effect. The chemistry of SOM under the various species and treatments did not show significant changes either. The low number of available replicates that is two was clearly insufficient to overcome the effect of spatial variation on litter chemistry and detect small differences in molecular litter chemistry.

Litter Quality of Populus Species as Affected by Free-Air CO2 Enrichment and N-Fertilization

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Esther Vermue

2009-01-01

Full Text Available The effect of elevated CO2 and nitrogen fertilization on the molecular chemistry of litter of three Populus species and associated soil organic matter (SOM was investigated by pyrolysis-gas chromatography/mass spectrometry. The results are based on 147 quantified organic compounds in 24 litter samples. Litter of P. euramerica was clearly different from that of P. nigra and P. alba. The latter two had higher contents of proteins, polysaccharides, and cutin/cutan, while the former had higher contents of phenols and benzofurans/pyrans. The difference between replications was at least as large as the effect of treatments, so that no systematic chemical changes were attributable to CO2 effect or N-fertilization effect. The chemistry of SOM under the various species and treatments did not show significant changes either. The low number of available replicates that is two was clearly insufficient to overcome the effect of spatial variation on litter chemistry and detect small differences in molecular litter chemistry.

Biochemical and Physiological Studies on the Effects of Senescence Leaves of Populus deltoides on Triticum vulgare

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Tejinder Pal Khaket

2014-01-01

Full Text Available Triticum vulgare (Wheat based products are the major dietary source of food in developing countries. In India, it grows in association with boundary plantations of Populus deltoids (poplar. During winter, poplar enters in dormancy which cause a heavy leaf fall at the time of wheat seed germination. Large number of poplar senescence leaves may adversely affect the wheat. Therefore, the present study was performed to examine the effect of senescence poplar leaves on wheat germ and some other biochemical parameters. Seed’s germination rate was determined by measuring root and shoot lengths, percent germination, germination index, and inhibition percentage. Biochemical parameters, namely, pigment, carbohydrate, protein, and phenol content, were estimated. Activities of catalase and polyphenol oxidase which are stress marker enzymes were also measured. Results revealed that germination and other biochemical parameters of wheat were severely affected by senescence poplar leaves even at very low concentration. So, intercropping of poplar along with wheat may be chosen carefully as wheat is the major dietary staple.

Hydrologic control on the root growth of Salix cuttings at the laboratory scale

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Bau', Valentina; Calliari, Baptiste; Perona, Paolo

2017-04-01

Riparian plant roots contribute to the ecosystem functioning and, to a certain extent, also directly affect fluvial morphodynamics, e.g. by influencing sediment transport via mechanical stabilization and trapping. There is much both scientific and engineering interest in understanding the complex interactions among riparian vegetation and river processes. For example, to investigate plant resilience to uprooting by flow, one should quantify the probability that riparian plants may be uprooted during specific flooding event. Laboratory flume experiments are of some help to this regard, but are often limited to use grass (e.g., Avena and Medicago sativa) as vegetation replicate with a number of limitations due to fundamental scaling problems. Hence, the use of small-scale real plants grown undisturbed in the actual sediment and within a reasonable time frame would be particularly helpful to obtain more realistic flume experiments. The aim of this work is to develop and tune an experimental technique to control the growth of the root vertical density distribution of small-scale Salix cuttings of different sizes and lengths. This is obtained by controlling the position of the saturated water table in the sedimentary bed according to the sediment size distribution and the cutting length. Measurements in the rhizosphere are performed by scanning and analysing the whole below-ground biomass by means of the root analysis software WinRhizo, from which root morphology statistics and the empirical vertical density distribution are obtained. The model of Tron et al. (2015) for the vertical density distribution of the below-ground biomass is used to show that experimental conditions that allow to develop the desired root density distribution can be fairly well predicted. This augments enormously the flexibility and the applicability of the proposed methodology in view of using such plants for novel flow erosion experiments. Tron, S., Perona, P., Gorla, L., Schwarz, M., Laio, F

Vegetation history reconstructed from anthracology and pollen analysis at the rescue excavation of the MO Motorway, Hungary

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Náfrádi, Katalin; Bodor, Elvira; Törőcsik, Tünde; Sümegi, Pál

2011-12-01

The significance of geoarchaeological investigations is indisputable in reconstructing the former environment and in studying the relationship between humans and their surroundings. Several disciplines have developed during the last few decades to give insight into earlier time periods and their climatic conditions (e.g. palynology, malacology, archaeobotany, phytology and animal osteology). Charcoal and pollen analytical studies from the rescue excavation of the MO motorway provide information about the vegetation changes of the past. These methods are used to reconstruct the environment of the former settlements and to detect the human impact and natural climatic changes. The sites examined span the periods of the Late-Copper Age, Late-Bronze Age, Middle-Iron Age, Late-Iron Age, Sarmatian period, Late Sarmatian period, Migration period, Late-Migration period and Middle Ages. The vegetation before the Copper Age is based only on pollen analytical data. Anthracological results show the overall dominance of Quercus and a great number of Ulmus, Fraxinus, Acer, Fagus, Alnus and Populus/Salix tree fossils, as well as the residues of fruit trees present in the charred wood assemblage.

Biology and management of insect pests in North American intensively managed hardwood forest systems.

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Coyle, David R.; Nebeker, T., E.; Hart, E., R.; Mattson, W., J.

2005-01-01

Annu. Rev. Entomol. 50:1-29. Abstract Increasing demand for wood and wood products is putting stress on traditional forest production areas, leading to long-term economic and environmental concerns. Intensively managed hardwood forest systems (IMHFS), grown using conventional agricultural as well as forestry methods, can help alleviate potential problems in natural forest production areas. Although IMHFS can produce more biomass per hectare per year than natural forests, the ecologically simplified, monocultural systems may greatly increase the crops susceptibility to pests. Species in the genera Populus and Salix comprise the greatest acreage in IMHFS in North America, but other species, including Liquidambar styracifua and Platanus occidentalis, are also important. We discuss life histories, realized and potential damage, and management options for the most economically infuential pests that affect these hardwood species. The substantial inherent challenges associated with pest management in the monocultural environments created by IMHFS are reviewed. Finally, we discuss ways to design IMHFS that may reduce their susceptibility to pests, increase their growth and productivity potential, and create a more sustainable environment.

Are cicadas (Diceroprocta apache) both a "keystone" and a "critical-link" species in lower Colorado River riparian communities?

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Andersen, Douglas C.

1994-01-01

Apache cicada (Homoptera: Cicadidae: Diceroprocta apache Davis) densities were estimated to be 10 individuals/m2 within a closed-canopy stand of Fremont cottonwood (Populus fremontii) and Goodding willow (Salix gooddingii) in a revegetated site adjacent to the Colorado River near Parker, Arizona. Coupled with data drawn from the literature, I estimate that up to 1.3 cm (13 1/m2) of water may be added to the upper soil layers annually through the feeding activities of cicada nymphs. This is equivalent to 12% of the annual precipitation received in the study area. Apache cicadas may have significant effects on ecosystem functioning via effects on water transport and thus act as a critical-link species in this southwest desert riverine ecosystem. Cicadas emerged later within the cottonwood-willow stand than in relatively open saltcedar-mesquite stands; this difference in temporal dynamics would affect their availability to several insectivorous bird species and may help explain the birds' recent declines. Resource managers in this region should be sensitive to the multiple and strong effects that Apache cicadas may have on ecosystem structure and functioning.

Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.

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Marx, D H

1977-03-01

The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species.

Diet preference of Eurasian Beaver (Castor Fiber L., 1758 in the environment of Oderské vrchy and its influence on the tree species composition of river bank stands

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Jan Dvořák

2013-01-01

Full Text Available This paper deals with the dietary behaviour and the tree species preference in the river bank stands in the diet of established population Eurasian Beaver (Castor fiber L., 1758 in the environment of Oderské vrchy; the objective is to assess the suitability of this environment for future development of the Eurasian Beaver and to asses the influence of the beaver’s dietary behaviour on the river bank stands. In the monitored area, the total of 5 tree species with the following preference were recorded: willow (Salix 42.2%, aspen (Populus 28%, dogwood (Comus 15.5%, birch (Betula 7.4% and alder (Alnus 6.9%. The most damaged diameter interval recorded within the all damaged tree species ranges from 2.6 to 6 cm, followed by the interval 6.1–12 cm. Over 61% of the trees felled by the beaver had a bigger diameter. The most sensitive reaction to beaver’s dietary behaviour was shown by aspen (reduction of numbers by 27.6% and by willow (reduction of numbers by 16.6% on the monitored area.

Phytoremediation trials on metal- and arsenic-contaminated pyrite wastes (Torviscosa, Italy).

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Vamerali, Teofilo; Bandiera, Marianna; Coletto, Lucia; Zanetti, Federica; Dickinson, Nicholas M; Mosca, Giuliano

2009-03-01

At a site in Udine, Italy, a 0.7m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15m layer of gravelly soil. This study investigates whether woody biomass phytoremediation is a realistic management option. Comparing ploughing and subsoiling (0.35m depth), the growth of Populus and Salix and trace element uptake were investigated in both pot and field trials. Species differences were marginal and species selection was not critical. Impaired above-ground productivity and low translocation of trace elements showed that bioavailable contaminant stripping was not feasible. The most significant finding was of coarse and fine roots proliferation in surface layers that provided a significant sink for trace elements. We conclude that phytostabilisation and effective immobilisation of metals and As could be achieved at the site by soil amelioration combined with woody species establishment. Confidence to achieve a long-term and sustainable remediation requires a more complete quantification of root dynamics and a better understanding of rhizosphere processes.

Ovule-to-seed development in Dovyalis caffra (Salicaceae: Flacourtieae with notes on the taxonomic significance of the extranucellar embryo sac

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E. M. A. Steyn

2005-08-01

Full Text Available Dovyalis caffra (Hook.f. & Harv. Hook.f. is a widespread and horticulturally important southern African endemic. Here described, ovule-to-seed development represents the first embryological information on this genus of the tribe Flacourtieae, Salicaceae  sensu lato. Results are discussed in the light of data available on the embryology of the order Malpighiales in general and on the tribe Flacourtieae in particular. It is clear that Dovyalis E.Mey. ex Am. shares many characters with other members of the Flacourtieae. Ovules of D. caffra are anatropous. bitegmic and crassinucellate with both bisporic Allium- and monosporic Polygonum-type embryo sacs. One of the most characteristic embryological features of the tribe is the pres­ence of an unusual, extranucellar embryo sac that stretches halfway up into the micropyle. Since this extraordinary-shaped embryo sac also defines the embryo sacs of Salix L. and Populus L., it is suggested that the character provides strong sup­port for the proposed close phylogenetic link between tribes Flacourtieae and Saliceae of Salicaceae sensu lato.

Mud-plastered granary-baskets at a Celtic Oppidum near Čarnok (Vojvodina, Serbia

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Medović Aleksandar

2011-01-01

Full Text Available In the Celtic Oppidum near Čarnok (Bačka, Vojvodina, Serbia remains of four mud-plastered granarybaskets were discovered. They are all dated to the period Gomolava VI-B (first half of the 1st century B.C.. Hulled barley and broomcorn millet were stored in the granary-baskets. The mesh of the granary-baskets was composed of young branches of oak tree (Quercus, common English elm tree (Ulmus cf. campestris L., poplar / willow (Populus / Salix, purgin buckthorn (Rhamnus cf. cathartica L., wayfaring tree (Viburnum cf. lantana L., spindle tree (Euonymus cf. europaeus L., barberry (Berberis vulgaris L. and a Pomoidae-tree. At least four different tree taxa were used for basket making. Construction of two-thousand-year old mud-plastered granary-baskets from the Pannonian plain is very similar to that of traditional granaries in some present-day villages in Africa. Additionally, one non-plastered basket was also discovered at Oppidum. It was build out of maple (Acer, barberry, buckthorn (Rhamnus and branches of a pomaceous fruits tree (Pomoidae. .

Changing contaminant mobility in a dredged canal sediment during a three-year phytoremediation trial

International Nuclear Information System (INIS)

King, Rosalind F.; Royle, Anna; Putwain, Philip D.; Dickinson, Nicholas M.

2006-01-01

Metal mobility and degradation of organic pollutants were investigated in a contaminated canal sediment in NW England. Sediment was dredged and exposed above the water surface, planted with multiple taxa of Salix, Populus and Alnus and monitored over 32 months. Short-term metal fractionation and phytotoxicity during sediment oxidation were also evaluated in separate laboratory studies. Zinc and Pb redistributed into more mobile fractions, which increased toxicity of the sediment to plants in the laboratory. In contrast, at the canal site, mobility of most elements decreased and total concentrations of Zn, Pb, Cu and Cd fell. Petroleum hydrocarbon concentrations decreased, but the tree-planted treatments appeared less effective at reducing PAH concentrations than treatments colonised by invasive plants. Tree survivorship decreased over time, suggesting increasing phytotoxicity of the exposed sediment in the longer term. Trees provided little benefit in terms of sediment remediation. Options for future management of the sediment are evaluated. - Highly mobilised and toxic metals in a dredged canal sediment provided unexpected responses in a phytoremediation trial

Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

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Saeid ESHAGHI

2012-05-01

Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves� propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves� propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves� propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves� propagation test for detection of collapse that occurs in wood during drying process was not useful.

Evaluation of Internal Cracks and Collapse in Poplar Wood (Populus nigra during a Conventional Drying Process with Ultrasonic Inspection

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Saeid ESHAGHI

2012-05-01

Full Text Available In this research, internal cracks and collapse of wood, formed during drying process, were measured using ultrasonic inspection. For this purpose, seven poplar (Populus nigra small blocks were dried, according to a time-based schedule. Ultrasonic waves propagation velocity was measured at both parallel and perpendicular to grain directions, using Sylvatest ultrasound device, during kiln drying process. Results showed that in all dried blocks, waves propagation velocity in the parallel direction was higher than in the perpendicular direction to grain. Ultrasonic waves propagation test for non-destructive identification of internal cracks, which occurs in wood during drying process in the parallel direction, was more successful compared to the perpendicular direction. Using ultrasonic waves propagation test for detection of collapse that occurs in wood during drying process was not useful.

Degradation of exogenous caffeine by Populus alba and its effects on endogenous caffeine metabolism.

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Pierattini, Erika C; Francini, Alessandra; Raffaelli, Andrea; Sebastiani, Luca

2016-04-01

This is the first study reporting the presence of endogenous caffeine, theobromine, and theophylline in all organs of poplar plants. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was used in order to evaluate the uptake, translocation, and metabolism of caffeine-(trimethyl-(13)C) in Populus alba L. Villafranca clone grown in hydroponic conditions. We investigated the remediation of caffeine since it is one of the most widely consumed drugs and it is frequently detected in wastewater treatment plant effluents, surface water, and groundwater worldwide. Our results demonstrated that poplar can absorb and degrade exogenous caffeine without negative effects on plant health. Data showed that concentrations of all endogenous compounds varied depending on caffeine-(trimethyl-(13)C) treatments. In particular, in control conditions, endogenous caffeine, theobromine, and theophylline were mainly distributed in roots. On the other hand, once caffeine-(trimethyl-(13)C) was provided, this compound and its dimethy-(13)C metabolites are mainly localized at leaf level. In conclusion, our results support the possible use of Villafranca clone in association with other water treatment systems in order to complete the process of caffeine remediation.

The yield of natural trembling aspen (populus tremula L.) stands (northern and eastern anatolia)

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Misir, M.; Misir, N.

2013-01-01

Trembling aspen (Populus tremula L.) is one of the most resistant to cold natural species in Turkey. In spite of its importance, there is no research on the yield. Hence, site productivity was determined and yield Table for undisturbed natural trembling aspen stands in Turkey was developed. Data were obtained from a total of 46 plots ranging in age from 17 to 82 years. Yield Table indicates that trembling aspen is very slow growing in young and middle age and Current Annual Increment (CAI) and Mean Annual Increment (MAI) values do not reach its maximum value, even at age 70. This is a proof that trembling aspen is not a fast growing species as expected. The reason for its slow growth is attributed to very short period of growth at very high altitudes. However, in the event of 50 years rotation age, mean annual volume increments of 8.0, 3.6 and 1.1 m3 are estimated for trembling aspen for site classes I, II and III, respectively. At extended rotations, trees of pole sizes could be obtained on all site classes. (author)

Structural and kinetic basis for substrate selectivity in Populus tremuloides sinapyl alcohol dehydrogenase.

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Bomati, Erin K; Noel, Joseph P

2005-05-01

We describe the three-dimensional structure of sinapyl alcohol dehydrogenase (SAD) from Populus tremuloides (aspen), a member of the NADP(H)-dependent dehydrogenase family that catalyzes the last reductive step in the formation of monolignols. The active site topology revealed by the crystal structure substantiates kinetic results indicating that SAD maintains highest specificity for the substrate sinapaldehyde. We also report substantial substrate inhibition kinetics for the SAD-catalyzed reduction of hydroxycinnamaldehydes. Although SAD and classical cinnamyl alcohol dehydrogenases (CADs) catalyze the same reaction and share some sequence identity, the active site topology of SAD is strikingly different from that predicted for classical CADs. Kinetic analyses of wild-type SAD and several active site mutants demonstrate the complexity of defining determinants of substrate specificity in these enzymes. These results, along with a phylogenetic analysis, support the inclusion of SAD in a plant alcohol dehydrogenase subfamily that includes cinnamaldehyde and benzaldehyde dehydrogenases. We used the SAD three-dimensional structure to model several of these SAD-like enzymes, and although their active site topologies largely mirror that of SAD, we describe a correlation between substrate specificity and amino acid substitution patterns in their active sites. The SAD structure thus provides a framework for understanding substrate specificity in this family of enzymes and for engineering new enzyme specificities.

Comparison of Different Wood Species as Raw Materials for Bioenergy

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Bojana Klašnja

2013-12-01

Full Text Available Background and Purpose: Most projections of the global energy use predict that biomass will be an important component of primary energy sources in the coming decades. Short rotation plantations have the potential to become an important source of renewable energy in Europe because of the high biomass yields, a good combustion quality as solid fuel, ecological advantages and comparatively low biomass production costs. Materials and Methods: In this study, the wood of black locust Robinia pseudoacacia, white willow Salix alba L., poplars Populus deltoides and Populus x euramericana cl.I-214, aged eight years were examined. Immediately after the felling, sample discs were taken to assess moisture content, ash content, the width of growth rings, wood densities and calorific values, according to the standard methodology. Results:The mean values of willow, poplar and black locust wood density were 341 kg/m3, 336 kg/m3 and 602 kg/m3,respectively. The average heating values of willow poplar and black locust wood were 18.599 MJ/kg, 18.564 MJ/kg and 21.196 MJ/kg, respectively. The FVI index (average values was higher for black locust (17.186 than for poplar and willow clones, which were similar: 11.312 and 11.422 respectively. Conclusions: Black locust wood with a higher density, calorific value and ash content compared to poplar and willow wood proved to be a more suitable raw material as RES. However, it is very important, from the aspect of the application of wood of these tree species as RES, to also consider the influence of the biomass yield per unit area of the plantations established as “energy plantations”.

Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration

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McGrath, Justin M.; Karnosky, David F.; Ainsworth, Elizabeth A.

2010-01-01

Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO 2 ]) and elevated ozone concentration ([O 3 ]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO 2 ] and [O 3 ] predicted for ∼2050. The responses of two clones were compared during the first month of spring leaf out when CO 2 fumigation had begun, but O 3 fumigation had not. Trees in elevated [CO 2 ] plots showed a stimulation of leaf area index (36%), while trees in elevated [O 3 ] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO 2 ], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO 2 ]; however, the two clones responded differently to long-term growth at elevated [O 3 ]. The O 3 -sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O 3 ] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O 3 ] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O 3 ], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions. - Spring leaf flush is stimulated by elevated [CO 2 ] and suppressed by elevated [O 3 ] in aspen (Populus tremuloides).

Stem respiration of Populus species in the third year of free-air CO{sub 2} enrichment

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Bielen, B.; Geulemans, R. [Univ. of Antwerp, Dept. of Biology, Research Group of Plant and Vegetation Ecology, Wilrijk (Belgium); Scarascia-Mugnozza, G. [Univ. degli Studi della Tuscia, Dept. of Forest Environment and Resources, Viterbo (Italy)

2003-04-01

Carbon cycling in ecosystems, and especially in forests, is intensively studied to predict the effects of global climate change, and the role which forests may play in 'changing climate change'. One of the questions is whether the carbon balance of forests will be affected by increasing atmospheric CO{sub 2} concentrations. Regarding this question, effects of elevated [CO{sub 2}] on woody-tissue respiration have frequently been neglected. Stem respiration of three Populus species (P. alba L. (Clone 2AS-11), P. nigra L. (Clone Jean Pourtet), and P. x euramericana (Clone I-214)) was measured in a managed, high-density forest plantation exposed to free-air CO{sub 2} enrichment (POPFACE). During the period of measurements, in May of the third year, stem respiration rates were not affected by the FACE treatment. Moreover, FACE did not influence the relationships between respiration rate and both stem temperature and relative growth rate. The results were supported by the reported absence of a FACE-effect on growth and stem wood density. (au)

Metabolic functions of Pseudomonas fluorescens strains from Populus deltoides depend on rhizosphere or endosphere isolation compartment

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Collin M Timm

2015-10-01

Full Text Available The bacterial microbiota of plants is diverse, with 1,000s of operational taxonomic units (OTUs associated with any individual plant. In this work we investigate the differences between 19 sequenced Pseudomonas fluorescens strains, isolated from Populus deltoides rhizosphere and endosphere and which represent a single OTU, using phenotypic analysis, comparative genomics, and metabolic models. While no traits were exclusive to either endosphere or rhizosphere P. fluorescens isolates, multiple pathways relevant for plant-bacterial interactions are enriched in endosphere isolate genomes. Further, growth phenotypes such as phosphate solubilization, protease activity, denitrification and root growth promotion are biased towards endosphere isolates. Endosphere isolates have significantly more metabolic pathways for plant signaling compounds and an increased metabolic range that includes utilization of energy rich nucleotides and sugars, consistent with endosphere colonization. Rhizosphere P. fluorescens have fewer pathways representative of plant-bacterial interactions but show metabolic bias towards chemical substrates often found in root exudates. This work reveals the diverse functions that may contribute to colonization of the endosphere by bacteria and are enriched among closely related isolates.

Determination of As in tree-rings of poplar (Populus alba L.) by U-shaped DC arc.

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Marković, D M; Novović, I; Vilotić, D; Ignjatović, Lj

2009-04-01

An argon-stabilized U-shaped DC arc with a system for aerosol introduction was used for determination of As in poplar (Populus alba L.) tree-rings. After optimization of the operating parameters and selection of the most appropriate signal integration time (30 s), the limit of detection for As was reduced to 15.0 ng/mL. This detection limit obtained with the optimal integration time was compared with those for other methods: inductively coupled plasma-atomic emission spectrometry (ICP-AES), direct coupled plasma-atomic emission spectrometry (DCP-AES), microwave induced plasma-atomic emission spectrometry (MIP-AES) and improved thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). Arsenic is toxic trace element which can adversely affect plant, animal and human health. As an indicator of environment pollution we collected poplar tree-rings from two locations. The first area was close to the "Nikola Tesla" (TENT-A) power plant, Obrenovac, while the other was in the urban area of Novi Sad. In all cases elevated average concentrations of As were registered in poplar tree-rings from the Obrenovac location.

Optimization of agrobacterium tumefaciens mediated transformation in populus deltoides

International Nuclear Information System (INIS)

John, E.; Maqbool, A.; Malik, K.A.

2014-01-01

The objective of the study was to develop an efficient protocol for Populus deltoides transformation through Agrobacterium tumefaciens LBA4404. Agrobacterium strain harboring binary plasmid pGA482 with Gus (uidA) gene under CamV35S promoter and Neomycin phosphotransferase (nptII) gene under Nos promoter was used for the transformation. Nodal, internodal and leaf explants from 4-5 months In vitro and fieldgrown plants were used for the transformation. Transformation was done under different conditions including, preculture time, optical density, acetosyringone concentration, infection time and co-cultivation time. Confirmation of transformation was done through GUS histochemical staining. Highest transformation efficiency was observed in one week precultured leaf explants from field grown source on preculture medium containing 200 meu M acetosyringone. Precultured explants from In vitro source also gave good results for transformation but the callus formation was found to be slow in leaf explant. Calli from the both sources did not show any transformation when infected with O.D A600nm range from 0.3-0.8. Node and internode though showed less transformation rate but the callogenesis was found to be highest in node and internode explants on CIM 1. Leaf explants from field source also gave high callus induction on CIM 5. A. tumefaciens O.D A600nm 0.3-0.5 was found to be effective. Infection time of 1-2 hour and co-cultivation time of 1day in dark were found to be optimum for the transformation. 200mg/l of timentin was found the best to control the overgrowth of Agrobacterium.100mg/l Kanamycin in growth medium was found to sufficient for selection for transformants. Selected transformants were confirmed through PCR for the presence of transgene. The present protocol for P. deltoides was found to be efficient for genetic transformation and can be used to introduce novel traits in the P. deltoides. (author)

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

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Yang, Fan; Wang, Yong; Chan, Zhulong

2014-01-01

The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

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Fan Yang

Full Text Available The establishment of riparian protection forests in the Three Gorges Reservoir (TGR is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ. Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress

Niche construction within riparian corridors. Part I: Exploring biogeomorphic feedback windows of three pioneer riparian species (Allier River, France)

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Hortobágyi, Borbála; Corenblit, Dov; Steiger, Johannes; Peiry, Jean-Luc

2018-03-01

Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody vegetation strongly influenced by hydrogeomorphic constraints (e.g., sediment transport and deposition, shear stress, hydrological variability), fluvial landforms, and morphodynamics, which in turn are modulated by the established vegetation. During field investigations in spring 2015, we studied 16 alluvial bars (e.g., point and lateral bars) within the dynamic riparian corridor of the Allier River (France) to assess the aptitude of three pioneer riparian Salicaceae species (Populus nigra L., Salix purpurea L., and Salix alba L.) to establish and act as ecosystem engineers by trapping sediment and constructing fluvial landforms. Our aim is to empirically identify the preferential establishment area (EA; i.e., the local areas where species become established) and the preferential biogeomorphic feedback window (BFW; i.e., where and to what extent the species and geomorphology interact) of these three species on alluvial bars within a 20-km-long river reach. Our results show that the EA and BFW of all three species vary significantly along the longitudinal profile, i.e., upstream-downstream exposure on the alluvial bars, as well as transversally, i.e., the main hydrological connectivity gradient from the river channel toward the floodplain. In the present-day context of the Allier River, P. nigra is the most abundant species, appearing to act as the main engineer species affecting landform dynamics at the bar scale; S. purpurea is established and acts as an ecosystem engineer at locations on alluvial bars that are most exposed to hydrosedimentary flow dynamics, while S. alba is established on the bar tail close to secondary channels and affects the geomorphology in mixed patches along with P. nigra. Our study highlights the role of functional trait diversity of riparian engineer species in controlling the extent of fluvial landform construction along geomorphic gradients within riparian

Local biotic adaptation of trees and shrubs to plant neighbors

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Grady, Kevin C.; Wood, Troy E.; Kolb, Thomas E.; Hersch-Green, Erika; Shuster, Stephen M.; Gehring, Catherine A.; Hart, Stephen C.; Allan, Gerard J.; Whitham, Thomas G.

2017-01-01

Natural selection as a result of plant–plant interactions can lead to local biotic adaptation. This may occur where species frequently interact and compete intensely for resources limiting growth, survival, and reproduction. Selection is demonstrated by comparing a genotype interacting with con- or hetero-specific sympatric neighbor genotypes with a shared site-level history (derived from the same source location), to the same genotype interacting with foreign neighbor genotypes (from different sources). Better genotype performance in sympatric than allopatric neighborhoods provides evidence of local biotic adaptation. This pattern might be explained by selection to avoid competition by shifting resource niches (differentiation) or by interactions benefitting one or more members (facilitation). We tested for local biotic adaptation among two riparian trees, Populus fremontii and Salix gooddingii, and the shrub Salix exigua by transplanting replicated genotypes from multiple source locations to a 17 000 tree common garden with sympatric and allopatric treatments along the Colorado River in California. Three major patterns were observed: 1) across species, 62 of 88 genotypes grew faster with sympatric neighbors than allopatric neighbors; 2) these growth rates, on an individual tree basis, were 44, 15 and 33% higher in sympatric than allopatric treatments for P. fremontii, S. exigua and S. gooddingii, respectively, and; 3) survivorship was higher in sympatric treatments for P. fremontiiand S. exigua. These results support the view that fitness of foundation species supporting diverse communities and dominating ecosystem processes is determined by adaptive interactions among multiple plant species with the outcome that performance depends on the genetic identity of plant neighbors. The occurrence of evolution in a plant-community context for trees and shrubs builds on ecological evolutionary research that has demonstrated co-evolution among herbaceous taxa, and

Phylogenomic Analysis and Dynamic Evolution of Chloroplast Genomes in Salicaceae

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Yuan Huang

2017-06-01

Full Text Available Chloroplast genomes of plants are highly conserved in both gene order and gene content. Analysis of the whole chloroplast genome is known to provide much more informative DNA sites and thus generates high resolution for plant phylogenies. Here, we report the complete chloroplast genomes of three Salix species in family Salicaceae. Phylogeny of Salicaceae inferred from complete chloroplast genomes is generally consistent with previous studies but resolved with higher statistical support. Incongruences of phylogeny, however, are observed in genus Populus, which most likely results from homoplasy. By comparing three Salix chloroplast genomes with the published chloroplast genomes of other Salicaceae species, we demonstrate that the synteny and length of chloroplast genomes in Salicaceae are highly conserved but experienced dynamic evolution among species. We identify seven positively selected chloroplast genes in Salicaceae, which might be related to the adaptive evolution of Salicaceae species. Comparative chloroplast genome analysis within the family also indicates that some chloroplast genes are lost or became pseudogenes, infer that the chloroplast genes horizontally transferred to the nucleus genome. Based on the complete nucleus genome sequences from two Salicaceae species, we remarkably identify that the entire chloroplast genome is indeed transferred and integrated to the nucleus genome in the individual of the reference genome of P. trichocarpa at least once. This observation, along with presence of the large nuclear plastid DNA (NUPTs and NUPTs-containing multiple chloroplast genes in their original order in the chloroplast genome, favors the DNA-mediated hypothesis of organelle to nucleus DNA transfer. Overall, the phylogenomic analysis using chloroplast complete genomes clearly elucidates the phylogeny of Salicaceae. The identification of positively selected chloroplast genes and dynamic chloroplast-to-nucleus gene transfers in

Dendroclimatic potential of plains cottonwood (Populus deltoides subsp. monilifera) from the Northern Great Plains, USA

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Edmonson, Jesse; Friedman, Jonathan; Meko, David; Touchan, Ramzi; Scott, Julian; Edmonson, Alan

2014-01-01

A new 368-year tree-ring chronology (A.D. 1643–2010) has been developed in western North Dakota using plains cottonwood (Populus deltoides subsp. monilifera) growing on the relatively undisturbed floodplain of the Little Missouri River in the North Unit of Theodore Roosevelt National Park. We document many slow-growing living trees between 150–370 years old that contradict the common understanding that cottonwoods grow fast and die young. In this northern location, cottonwood produces distinct annual rings with dramatic interannual variability that strongly crossdate. The detrended tree-ring chronology is significantly positively correlated with local growing season precipitation and soil moisture conditions (r  =  0.69). This time series shows periods of prolonged low radial tree growth during the known droughts of the instrumental record (e.g. 1931–1939 and 1980–1981) and also during prehistory (e.g. 1816–1823 and 1856–1865) when other paleoclimate studies have documented droughts in this region. Tree rings of cottonwood will be a useful tool to help reconstruct climate, streamflow, and the floodplain history of the Little Missouri River and other northern river systems.

Salix transect of Europe: structured genetic variation and isolation-by-distance in the nettle psyllid, Trioza urticae (Psylloidea, Hemiptera), from Greece to Arctic Norway

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Wonglersak, Rungtip; Cronk, Quentin; Percy, Diana

2017-01-01

Abstract Background The common nettle (Urtica dioica L.) is co-associated with willows (Salix spp.) in riparian habitats across Europe. We sampled the widespread nettle psyllid, Trioza urticae (Linné, 1758), from Urtica in willow habitats on a megatransect of Europe from the Aegean to the Arctic Ocean. The aim of this study was to use an unusually widespread insect to assess the influence of geographic distances and natural geographic barriers on patterns of genetic variation and haplotype distribution. New information Phylogeographic analysis using DNA sequences of two mtDNA regions, COI and cytB, shows that T. urticae specimens are organized into four regional groups (southern, central, northern and arctic). These groups are supported by both phylogenetic analysis (four geographically-based clades) and network analysis (four major haplotype groups). The boundary between southern and central groups corresponds to the Carpathian Mountains and the boundary between the central and northern groups corresponds to the Gulf of Finland. Overall these groups form a latitudinal cline in genetic diversity, which decreases with increasing latitude. PMID:28325977

[Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of western Sichuan, China].

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Xu, Zhen-feng; Hu, Ting-xing; Zhang, Li; Zhang, Yuan-bin; Xian, Jun-ren; Wang, Kai-yun

2009-01-01

By using open-top chamber (OTC), the effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 1.2 m above the ground throughout S. eriostachya growth season in OTC increased by 2.9 degrees C, while the soil temperature at the depth of 5 cm only increased by 0.4 degrees C. The temperature increase in OTC made S. eriostachya budding advanced and defoliation postponed obviously, and the leaf life-span longer. The leaf and branch growth rates as well as the specific leaf area in OTC increased obviously, whereas the leaf nitrogen concentration decreased significantly. In OTC, the stomata conductance, net photosynthetic rate, photorespiration, and dark respiration rate of S. eriostachya all exhibited an increasing trend. It was suggested that S. eriostachya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution in the timberline ecotone would be likely to ascend.

Proteome analysis reveals an energy-dependent central process for Populus×canadensis seed germination.

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Zhang, Hong; Zhou, Ke-Xin; Wang, Wei-Qing; Liu, Shu-Jun; Song, Song-Quan

2017-06-01

Poplar (Populus×canadensis) seeds rapidly germinated in darkness at 10, 15, and 20°C and reached 50% seed germination after about 22, 4.5, and 3.5h, respectively. Germination of poplar seeds was markedly inhibited by abscisic acid (ABA) at 50μM and cycloheximide (CHX) at 100μM, and these inhibitive roles were temperature-dependent. In the present study, mature poplar seeds were used to investigate the differentially changed proteome of seeds germinating in water, ABA, and CHX. A total of 130 protein spots showed a significant change (1.5-fold increase/decrease, Pgermination of poplar seeds is closely related with the increase in those proteins involved in amino acid and lipid metabolism, the tricarboxylic acid cycle and pentose phosphate pathway, protein synthesis and destination, cell defense and rescue, and degradation of storage proteins. ABA and CHX inhibit the germination of poplar seeds by decreasing the protein abundance associated with protein proteolysis, protein folding, and storage proteins. We conclude that poplar seed germination is an energy-dependent active process, and is accompanied by increasing amino acid activation, protein synthesis and destination, as well as cell defense and rescue, and degradation of storage proteins. Copyright © 2017 Elsevier GmbH. All rights reserved.

Changes in lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass

International Nuclear Information System (INIS)

Foston, Marcus; Ragauskas, Art J.

2010-01-01

Dilute acid pretreatment (DAP) is commonly employed prior to enzymatic deconstruction of cellulose to increase overall sugar and subsequent ethanol yields from downstream bioconversion processes. Typically optimization of pretreatment is evaluated by determining hemicellulose removal, subsequent reactivity towards enzymatic deconstruction, and recoverable polysaccharide yields. In this study, the affect of DAP on the supramolecular and ultrastructure of lignocellulosic biomass was evaluated. A series of dilute acidic pretreatments, employing ∼0.10-0.20 mol/m 3 H 2 SO 4 at ∼160-180 o C, for varying residence times were conducted on both Populus and switchgrass samples. The untreated and pretreated biomass samples were characterized by carbohydrate and lignin analysis, gel permeation chromatography (GPC) and 13 C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. GPC analysis shows a reduction in the molecular weight of cellulose and change in its polydispersity index (PDI) with increasing residence time, indicating that pretreatment is actually degrading the cellulose chains. 13 C CPMAS and non-linear line-fitting of the C 4 region in the carbon spectrum of the isolated cellulose not only showed that the crystallinity index increases with residence time, but that the lateral fibril dimension (LFD) and lateral fibril aggregate dimension (LFAD) increase as well.

Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

Science.gov (United States)

Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

2012-01-01

We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

Genetic variation in functional traits influences arthropod community composition in aspen (Populus tremula L..

Directory of Open Access Journals (Sweden)

Kathryn M Robinson

Full Text Available We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores.

Investigations on the nutrient demands of different balsam poplar clones (Populus trichocarpa Torr. et Grey) based on growth, nutrient uptake, and vapor exchange. Untersuchungen ueber die Naehrstoffansprueche verschiedener Balsam-Pappelklone (Populus trichocarpa Torr. et Grey) in Hinsicht auf das Wachstum, die Naehrstoffaufnahme und den Gaswechsel

Energy Technology Data Exchange (ETDEWEB)

Griese, C.

1991-01-01

This work tries to describe the nutrient demands of six different, very fast-growing clones of the species Populus trichocarpa Torr. Et. Grey. Relevant are the capability for taking up different nutrients, and the plants' efficiency in using these nutrients for vapour exchange of the leaves (photosynthesis, respiration in the dark, transpiration) as well as for increasing biomass. A further aim pursued with these measurements is the attempt to explain the different growth of these six popular clones. Here, field experiments have shown a gradiation of the clones' growth performance. From the first to the sixth clone, growth performance declines steadily. Should there be differences among the clones as to the physiological, biometric and phenological variables to be investigated, then this work might lead to the identification of growth-determining factors suitable for postulating of the investigated clones. (orig.).

Significance of Lignin S/G Ratio in Biomass Recalcitrance of Populus trichocarpa Variants for Bioethanol Production

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Yoo, Chang Geun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dumitrache, Alexandru [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Muchero, Wellington [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Natzke, Jace [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Akinosho, Hannah [Georgia Inst. of Technology, Atlanta, GA (United States); Li, Mi [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sykes, Robert W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davison, Brian [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tuskan, Gerald A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pu, Yunqiao [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ragauskas, Arthur J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States)

2017-12-11

Lignin S/G ratio has been investigated as an important factor in biomass recalcitrance to bioethanol production. Because of the complexity and variety of biomass, recalcitrance was also reportedly influenced by several other factors, such as total lignin content, degree of cellulose polymerization, etc. In addition, the effect of S/G ratio on biomass conversion is not uniform across plant species. Herein, 11 Populus trichocarpa natural variants grown under the same conditions with similar total lignin content were selected to minimize the effects of other factors. The lignin S/G ratio of the selected P. trichocarpa natural variants showed negative correlations with p-hydroxybenzoate (PB) and β–5 linkage contents, while it had positive ones with β-O-4 linkage, lignin molecular weight, and ethanol production. In conclusion, this study showed the importance of lignin S/G ratio as an independent recalcitrance factor that may aid future energy crop engineering and biomass conversion strategies.

Significance of Lignin S/G Ratio in Biomass Recalcitrance of Populus trichocarpa Variants for Bioethanol Production

Energy Technology Data Exchange (ETDEWEB)

Yoo, Chang Geun [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; UT−ORNL; Dumitrache, Alexandru [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Muchero, Wellington [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Natzke, Jace [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Akinosho, Hannah [School; Li, Mi [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; UT−ORNL; Sykes, Robert W. [National Renewable Energy Laboratory, U.S. Department of Energy, 15013 Denver West Parkway, Golden, Colorado 80401, United States; Brown, Steven D. [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Davison, Brian [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Tuskan, Gerald A. [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; Pu, Yunqiao [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; UT−ORNL; Ragauskas, Arthur J. [BioEnergy; amp, Center for BioEnergy Innovation, Biosciences; UT−ORNL; Department; amp, Center for Renewable

2017-12-27

Lignin S/G ratio has been investigated as an important factor in biomass recalcitrance to bioethanol production. Because of the complexity and variety of biomass, recalcitrance was also reportedly influenced by several other factors, such as total lignin content, degree of cellulose polymerization, etc. In addition, the effect of S/G ratio on biomass conversion is not uniform across plant species. Herein, 11 Populus trichocarpa natural variants grown under the same conditions with similar total lignin content were selected to minimize the effects of other factors. The lignin S/G ratio of the selected P. trichocarpa natural variants showed negative correlations with p-hydroxybenzoate (PB) and ..beta..-5 linkage contents, while it had positive ones with ..beta..-O-4 linkage, lignin molecular weight, and ethanol production. This study showed the importance of lignin S/G ratio as an independent recalcitrance factor that may aid future energy crop engineering and biomass conversion strategies.

A microarray-based genotyping and genetic mapping approach for highly heterozygous outcrossing species enables localization of a large fraction of the unassembled Populus trichocarpa genome sequence.

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Drost, Derek R; Novaes, Evandro; Boaventura-Novaes, Carolina; Benedict, Catherine I; Brown, Ryan S; Yin, Tongming; Tuskan, Gerald A; Kirst, Matias

2009-06-01

Microarrays have demonstrated significant power for genome-wide analyses of gene expression, and recently have also revolutionized the genetic analysis of segregating populations by genotyping thousands of loci in a single assay. Although microarray-based genotyping approaches have been successfully applied in yeast and several inbred plant species, their power has not been proven in an outcrossing species with extensive genetic diversity. Here we have developed methods for high-throughput microarray-based genotyping in such species using a pseudo-backcross progeny of 154 individuals of Populus trichocarpa and P. deltoides analyzed with long-oligonucleotide in situ-synthesized microarray probes. Our analysis resulted in high-confidence genotypes for 719 single-feature polymorphism (SFP) and 1014 gene expression marker (GEM) candidates. Using these genotypes and an established microsatellite (SSR) framework map, we produced a high-density genetic map comprising over 600 SFPs, GEMs and SSRs. The abundance of gene-based markers allowed us to localize over 35 million base pairs of previously unplaced whole-genome shotgun (WGS) scaffold sequence to putative locations in the genome of P. trichocarpa. A high proportion of sampled scaffolds could be verified for their placement with independently mapped SSRs, demonstrating the previously un-utilized power that high-density genotyping can provide in the context of map-based WGS sequence reassembly. Our results provide a substantial contribution to the continued improvement of the Populus genome assembly, while demonstrating the feasibility of microarray-based genotyping in a highly heterozygous population. The strategies presented are applicable to genetic mapping efforts in all plant species with similarly high levels of genetic diversity.

Comparative study of volatile components from male and female flower buds of Populus × tomentosa by HS-SPME-GC-MS.

Science.gov (United States)

Xu, Liang; Liu, Haiping; Ma, Yucui; Wu, Cui; Li, Ruiqi; Chao, Zhimao

2018-06-13

The differences of volatile components in male (MFB) and female flower buds (FFB) of Populus × tomentosa were analysed and compared by HS-SPME with GC-MS for the first time. A total of 34 compounds were identified. Two clusters were clearly divided into male and female by hierarchical clustering analysis. Both the male and female flower buds showed methyl salicylate (22.83 and 24.09%, respectively) and 2-hydroxy-benzaldehyde (10.05 and 12.41%, respectively) as the main volatile constituents. The content of 2-cyclohexen-1-one, benzyl benzoate, and methyl benzoate in FFB was remarkably higher than in MFB. In contrast, the content of ethyl benzoate in MFB was greater than that in FFB. The phenomena showed the characteristic differences between MFB and FFB of P. × tomentosa, which enriched the basic studies on dioecious plant.

Physiological and biochemical responses of Salix integra Thunb. under copper stress as affected by soil flooding.

Science.gov (United States)

Cao, Yini; Ma, Chuanxin; Chen, Guangcai; Zhang, Jianfeng; Xing, Baoshan

2017-06-01

To explore the joint effect of copper (Cu) and flooding on Salix integra Thunb. (S. integra), the physiological and biochemical parameters of the seedlings grown in Cu amended soil (50, 150, 450 mg kg -1 ) with or without the flooding for 60 days were evaluated. The results suggested that the flooding significantly inhibited the root growth in terms of root length and root tips. The Cu exposures of 50 and 150 mg kg -1 notably enhanced the root growth as compared to the control. Majority of Cu was accumulated in S. integra roots, while flooding significantly reduced the Cu content, except the 150 mg kg -1 Cu treatment, but the iron (Fe) and manganese (Mn) content on the root surface were both markedly increased relative to non-flooded control. The malonaldehyde (MDA) and glutathione (GSH) contents in leaves showed a dose-response upon Cu exposure. Soil flooding enhanced the GSH level, which displayed 4.50-49.59% increases compared to its respective non-flooded treatment, while no difference was evident on MDA contents between the flooding and the non-flooded treatments. Both superoxide dismutase (SOD) and peroxidase (POD) activities were boosted while the catalase (CAT) was suppressed with increasing Cu exposure dose, and soil flooding reduced the POD and CAT activities. The elevated Cu level caused the evident increases of root calcium (Ca), potassium (K), and sulfur (S) concentrations and decreases of root phosphorus (P), sodium (Na), and zinc (Zn) concentrations. Soil flooding increased the concentrations of Fe, S, Na, Ca, and magnesium (Mg) in S. integra root. Taken together, our results suggested S. integra has high tolerance to the joint stress from Cu and flooding. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variations in metal tolerance and accumulation in three hydroponically cultivated varieties of Salix integra treated with lead.

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Shufeng Wang

Full Text Available Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou, a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production, but a low translocation factor (TF, indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests.

Variations in Metal Tolerance and Accumulation in Three Hydroponically Cultivated Varieties of Salix integra Treated with Lead

Science.gov (United States)

Sun, Haijing; Chen, Yitai; Pan, Hongwei; Yang, Xiaoe; Rafiq, Tariq

2014-01-01

Willow species have been suggested for use in the remediation of contaminated soils due to their high biomass production, fast growth, and high accumulation of heavy metals. The tolerance and accumulation of metals may vary among willow species and varieties, and the assessment of this variability is vital for selecting willow species/varieties for phytoremediation applications. Here, we examined the variations in lead (Pb) tolerance and accumulation of three cultivated varieties of Salix integra (Weishanhu, Yizhibi and Dahongtou), a shrub willow native to northeastern China, using hydroponic culture in a greenhouse. In general, the tolerance and accumulation of Pb varied among the three willow varieties depending on the Pb concentration. All three varieties had a high tolerance index (TI) and EC50 value (the effective concentration of Pb in the nutrient solution that caused a 50% inhibition on biomass production), but a low translocation factor (TF), indicating that Pb sequestration is mainly restricted in the roots of S. integra. Among the three varieties, Dahogntou was more sensitive to the increased Pb concentration than the other two varieties, with the lowest EC50 and TI for root and above-ground tissues. In this respect, Weishanhu and Yizhibi were more suitable for phytostabilization of Pb-contaminated soils. However, our findings also indicated the importance of considering the toxicity symptoms when selecting willow varieties for the use of phytoremediation, since we also found that the three varieties revealed various toxicity symptoms of leaf wilting, chlorosis and inhibition of shoot and root growth under the higher Pb concentrations. Such symptoms could be considered as a supplementary index in screening tests. PMID:25268840

Combined enhancements of temperature and UVB influence growth and phenolics in clones of the sexually dimorphic Salix myrsinifolia

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Nybakken, L.; Hoerkkae, R.; Julkunen-Tiitto, R. (Univ. of Eastern Finland. Dept. of Biology, Joensuu (Finland))

2012-08-15

Although several climatic factors are expected to change simultaneously in the future, the effect of such combined changes on plants have seldom been tested under field conditions. We report on a field experiment with dark-leaved willow, Salix myrsinifolia, subjected to enhancements in ultraviolet-A (UVA), UVB radiation and temperature, setup in Joensuu, Eastern Finland. S. myrsinifolia is a dioecious species, known as an important food plant for many herbivores. Cuttings of eight clones, four of each sex, of dark-leaved willow were planted in the field in spring 2009. In both 2009 and 2010, the total biomass increased significantly with temperature, and in 2010 there was an additive effect of UVB radiation. Both height and diameter increased with temperature in 2009, while the effect on height growth ceased in 2010. Males had greater diameter growth than females in 2010. Most phenolic compounds in the leaves decreased under enhanced temperature in both growing seasons. In 2010, four of six salicylates increased in response to enhanced temperature. Some quercetin derivatives increased under enhanced UVB radiation. Females had higher concentrations of chlorogenic acids than males, and while enhanced temperature reduced chlorogenic acid in females only, luteolins were reduced only in males. In summary, the combined enhancements gave no effects in addition to those that appeared under the single-factor treatments, except for the additive effect of UVB on temperature-increased biomass. The few gender-related differences found in response to climate change do not allow any marked expectations of future climate-induced changes in sex ratios. (Author)

Energy dynamics in Populus deltoides G3 Marsh agroforestry systems in eastern India

International Nuclear Information System (INIS)

Chaturvedi, O.P.; Das, D.K.

2005-01-01

Energy efficiency of Populus deltoides G 3 Marsh agroforestry of a 3-year-old system with intercropping of maize-wheat in crop I and pigeonpea in crop II and of a 9-year-old system with turmeric, a shade loving crop was studied at Pusa, Bihar in eastern India. Energy fixation, storage, net allocation in agronomic yield and energy released and exit from the 9-year-old system was 1.53, 4.30, 0.43 and 3.37 times in crop I and 1.67, 4.60, 0.53 and 3.30 times in crop II of the 3-year-old agroforestry system. The energy conservation efficiency in the 9-year-old system was higher (1.91%) as compared to crop I (1.24%) and crop II (1.15%) of the 3-year-old agroforestry system. The energy accumulation ratio in the 9-year-old system was 2.82 and 2.77 times higher in crop I and crop II, respectively, of the 3-year-old agroforestry system. The 3-year-old agroforestry system showed lower energy accumulation ratio resulting from less energy accumulation in perennial turnover in the from of leaf of tree and agricultural crops. The crop II system of the 3-year-old poplar agroforestry was more efficient system of management due to higher quanta of energy and higher cash return but one has to opt for shade loving intercrop turmeric with increase in age of the poplar plantation and more canopy closure

High yielding biomass genotypes of willow (Salix spp.) show differences in below ground biomass allocation

International Nuclear Information System (INIS)

Cunniff, Jennifer; Purdy, Sarah J.; Barraclough, Tim J.P.; Castle, March; Maddison, Anne L.; Jones, Laurence E.; Shield, Ian F.; Gregory, Andrew S.; Karp, Angela

2015-01-01

Willows (Salix spp.) grown as short rotation coppice (SRC) are viewed as a sustainable source of biomass with a positive greenhouse gas (GHG) balance due to their potential to fix and accumulate carbon (C) below ground. However, exploiting this potential has been limited by the paucity of data available on below ground biomass allocation and the extent to which it varies between genotypes. Furthermore, it is likely that allocation can be altered considerably by environment. To investigate the role of genotype and environment on allocation, four willow genotypes were grown at two replicated field sites in southeast England and west Wales, UK. Above and below ground biomass was intensively measured over two two-year rotations. Significant genotypic differences in biomass allocation were identified, with below ground allocation differing by up to 10% between genotypes. Importantly, the genotype with the highest below ground biomass also had the highest above ground yield. Furthermore, leaf area was found to be a good predictor of below ground biomass. Growth environment significantly impacted allocation; the willow genotypes grown in west Wales had up to 94% more biomass below ground by the end of the second rotation. A single investigation into fine roots showed the same pattern with double the volume of fine roots present. This greater below ground allocation may be attributed primarily to higher wind speeds, plus differences in humidity and soil characteristics. These results demonstrate that the capacity exists to breed plants with both high yields and high potential for C accumulation. - Highlights: • SRC willows are a source of biomass and act as carbon (C) sinks. • Biomass allocation was measured in 4 willow genotypes grown in two UK field sites. • The greatest yielding genotype had the greatest below ground biomass at both sites. • Below ground biomass allocation differed by up to 10% between genotypes and 94% between sites. • Environment e.g. wind

Organ and Tissue-specific Sucrose Transporters. Important Hubs in Gene and Metabolite Networks Regulating Carbon Use in Wood-forming Tissues of Populus

Energy Technology Data Exchange (ETDEWEB)

Harding, Scott A. [Univ. of Georgia, Athens, GA (United States); Tsai, Chung-Jui [Univ. of Georgia, Athens, GA (United States)

2016-01-04

The overall project objective was to probe the relationship between sucrose transporters and plant productivity in the biomass for biofuels woody perennial, Populus. At the time the proposal was written, sucrose transporters had already been investigated in many plant model systems, primarily with respect to the export of photosynthate sucrose from source leaves, and the uptake of sucrose in storage organs and seeds. Preliminary findings by the PI found that in Populus, sucrose transporter genes (SUTs) were well expressed in wood-forming tissues that comprise the feedstock for biofuels production. Because sucrose comprises by far the predominant form in which photosynthate is delivered from source organs to sink organs like roots and wood-forming tissues, SUTs control a gate that nominally at least could impact the allocation or partitioning of sucrose for potentially competing end uses like growth (stem biomass) and storage. In addition, water use might be conditioned by the way in which sucrose is distributed throughout the plant, and/or by the way in which sucrose is partitioned intracellularly. Several dozen transgenic lines were produced in year 1 of the project to perturb the expression ratio of multiple plasma membrane (PM) SUTs (intercellular trafficking), versus the single tonoplast membrane (TM) sucrose transporter that effectively regulates intracellular trafficking of sucrose. It was possible to obtain transgenic lines with dual SUT gene knockdown using the 35S promoter, but not the wood-specific TUA1 promoter. By the end of project year 2, a decision was made to work with the 35S plants while archiving the TUA1 plants. The PhD candidate charged with producing the transgenic lines abandoned the project during its second year, substantially contributing to the decision to operate with just the 35S lines. That student’s interests ranged more toward evolutionary topics, and a report on SUT gene evolution was published (Peng et al 2014).

Sex-specific responses to winter flooding, spring waterlogging and post-flooding recovery in Populus deltoides.

Science.gov (United States)

Miao, Ling-Feng; Yang, Fan; Han, Chun-Yu; Pu, Yu-Jin; Ding, Yang; Zhang, Li-Jia

2017-05-31

Winter flooding events are common in some rivers and streams due to dam constructions, and flooding and waterlogging inhibit the growth of trees in riparian zones. This study investigated sex-specific morphological, physiological and ultrastructural responses to various durations of winter flooding and spring waterlogging stresses, and post-flooding recovery characteristics in Populus deltoides. There were no significant differences in the morphological, ultrastructural and the majority of physiological traits in trees subjected to medium and severe winter flooding stresses, suggesting that males and females of P. deltoides were winter flooding tolerant, and insensitive to winter flooding duration. Males were more tolerant to winter flooding stress in terms of photosynthesis and chlorophyll fluorescence than females. Females displayed greater oxidative damage due to flooding stress than males. Males developed more efficient antioxidant enzymatic systems to control reactive oxygen species. Both sexes had similarly strong post-flooding recovery capabilities in terms of plant growth, and physiological and ultrastructural parameters. However, Males had better recovery capabilities in terms of pigment content. These results increase the understanding of poplars's adaptation to winter flooding stress. They also elucidate sex-specific differences in response to flooding stress during the dormant season, and during post-flooding recovery periods.

Differential transcriptome analysis between Populus and its synthesized allotriploids driven by second-division restitution.

Science.gov (United States)

Cheng, Shiping; Huang, Zhen; Li, Yun; Liao, Ting; Suo, Yujing; Zhang, Pingdong; Wang, Jun; Kang, Xiangyang

2015-12-01

In this report, we compared transcriptomic differences between a synthetic Populus section Tacamahaca triploid driven by second-division restitution and its parents using a high-throughput RNA-seq method. A total of 4,080 genes were differentially expressed between the high-growth vigor allotriploids (SDR-H) and their parents, and 719 genes were non-additively expressed in SDR-H. Differences in gene expression between the allotriploid and male parent were more significant than those between the allotriploid and female parent, which may be caused by maternal effects. We observed 3,559 differentially expressed genes (DEGs) between the SDR-H and male parent. Notably, the genes were mainly involved in metabolic process, cell proliferation, DNA methylation, cell division, and meristem and developmental growth. Among the 1,056 DEGs between SDR-H and female parent, many genes were associated with metabolic process and carbon utilization. In addition, 1,789 DEGs between high- and low-growth vigor allotriploid were mainly associated with metabolic process, auxin poplar transport, and regulation of meristem growth. Our results indicated that the higher poplar ploidy level can generate extensive transcriptomic diversity compared with its parents. Overall, these results increased our understanding of the driving force for phenotypic variation and adaptation in allopolyploids driven by second-division restitution. © 2015 Institute of Botany, Chinese Academy of Sciences.

Where the Rubber Meets the Road; Varied Techniques for Measuring the Land-Atmosphere Exchange of Water and Energy in a California Watershed and the Driving Influences on this Exchange

Science.gov (United States)

Kochendorfer, J.; Viers, J.; Niswonger, R.; Paw U, K.; Haas, E.; Reck, R. A.

2005-12-01

In conjunction with the Cosumnes Research Group, we performed a field study along the Cosumnes River in California's Central Valley. The study included tower-based evapotranspiration estimates, continuous hydrologic measurements, and analysis of remote sensing data. We estimated the effects of phreatophytic evapotranspiration on groundwater from scales as small as an individual stand of trees to as large as the watershed and explored the climactic and hydrologic controls over riparian evapotranspiration. Tower-based evapotranspiration measurements included one eddy covariance tower within a cottonwood forest (Populus fremontii), and one surface temperature/micrometeorological evapotranspiration tower within a willow stand (Salix lasiolepis). The technique used on the surface temperature/micrometeorological evapotranspiration tower was developed and chosen in preference to eddy covariance for a site where a considerable quantity of the riparian ecosystem to atmosphere exchange is advective. Hydrologic techniques included measurements of groundwater depth and volumetric soil moisture. We also examined multitemporal, multiresolution remotely sensed imagery to correlate evapotranspiration rates for a restored cottonwood forest with derived vegetation indices. These indices were evaluated for applicability to other restored riparian habitats within the Cosumnes River Preserve and to help guide future restoration actions as a function of hydrologic connectivity and water demand.

Energetic evaluation of indigenous tree and shrub species in Basilicata, Southern Italy

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Todaro L

2007-01-01

Full Text Available An evaluation of energetic characteristics such as high calorific value (on ash-free dry weight basis, ash, carbon, nitrogen, and moisture content of 12 indigenous tree and shrub species of Southern Italy (Basilicata Region was carried out. The studied species are the most abundant in this area: Quercus cerris L., Quercus pubescens Willd., Fraxinus ornus L., Populus canescens (Aiton Smith, Salix alba L., Alnus cordata L., Robinia pseudoacacia L., Olea europaea L., Spartium junceum L., Rubus hirtus W., Onopordum illirium L., Arundo donax L. For Q. cerris, Q. pubescens and O. europaea L., the energetic characteristics were measured by separating the wood components from the leaves. Q. cerris leaves contained the greatest high calorific value. F. ornus leaves had a greater ash content than the other samples while the lowest values were measured for S. junceum, Q. pubescens and R. pseudoacacia. The highest content of Carbon was in O. europaea leaves. A. donax and O. illirium had the lower level of high calorific value and Carbon than all the other species. The highest Nitrogen content was measured in Q. cerris leaves and the lowest one in F. ornus wood components.

Greenhouse gas emissions from a Cu-contaminated soil remediated by in situ stabilization and phytomanaged by a mixed stand of poplar, willows, and false indigo-bush.

Science.gov (United States)

Šimek, M; Elhottová, D; Mench, M; Giagnoni, L; Nannipieri, P; Renella, G

2017-11-02

Phytomanagement of trace element-contaminated soils can reduce soil toxicity and restore soil ecological functions, including the soil gas exchange with the atmosphere. We studied the emission rate of the greenhouse gases (GHGs) CO 2 , CH 4 , and N 2 O; the potential CH 4 oxidation; denitrification enzyme activity (DEA), and glucose mineralization of a Cu-contaminated soil amended with dolomitic limestone and compost, alone or in combination, after a 2-year phytomanagement with a mixed stand of Populus nigra, Salix viminalis, S. caprea, and Amorpha fruticosa. Soil microbial biomass and microbial community composition after analysis of the phospholipid fatty acids (PLFA) profile were determined. Phytomanagement significantly reduced Cu availability and soil toxicity, increased soil microbial biomass and glucose mineralization capacity, changed the composition of soil microbial communities, and increased the CO 2 and N 2 O emission rates and DEA. Despite such increases, microbial communities were evolving toward less GHG emission per unit of microbial biomass than in untreated soils. Overall, the aided phytostabilization option would allow methanotrophic populations to establish in the remediated soils due to decreased soil toxicity and increased nutrient availability.

Modelling the growth of Populus species using Ecosystem Demography (ED) model

Science.gov (United States)

Wang, D.; Lebauer, D. S.; Feng, X.; Dietze, M. C.

2010-12-01

Hybrid poplar plantations are an important source being evaluated for biomass production. Effective management of such plantations requires adequate growth and yield models. The Ecosystem Demography model (ED) makes predictions about the large scales of interest in above- and belowground ecosystem structure and the fluxes of carbon and water from a description of the fine-scale physiological processes. In this study, we used a workflow management tool, the Predictive Ecophysiological Carbon flux Analyzer (PECAn), to integrate literature data, field measurement and the ED model to provide predictions of ecosystem functioning. Parameters for the ED ensemble runs were sampled from the posterior distribution of ecophysiological traits of Populus species compiled from the literature using a Bayesian meta-analysis approach. Sensitivity analysis was performed to identify the parameters which contribute the most to the uncertainties of the ED model output. Model emulation techniques were used to update parameter posterior distributions using field-observed data in northern Wisconsin hybrid poplar plantations. Model results were evaluated with 5-year field-observed data in a hybrid poplar plantation at New Franklin, MO. ED was then used to predict the spatial variability of poplar yield in the coterminous United States (United States minus Alaska and Hawaii). Sensitivity analysis showed that root respiration, dark respiration, growth respiration, stomatal slope and specific leaf area contribute the most to the uncertainty, which suggests that our field measurements and data collection should focus on these parameters. The ED model successfully captured the inter-annual and spatial variability of the yield of poplar. Analyses in progress with the ED model focus on evaluating the ecosystem services of short-rotation woody plantations, such as impacts on soil carbon storage, water use, and nutrient retention.

Determination of the Annual Shading Potential of Salix Purpurea Coppice using Hemispherical Photographs

Science.gov (United States)

Holzapfel, G.; Weihs, P.; Stockreiter, L.; Hoffmann, E.

2012-04-01

densities in terms of Leaf Area Index (LAI) and the corresponding incident solar radiation energy reaching a shaded water surface (Global Site Factor). Responding to these questions a two year old natural stand of Salix purpurea was monitored. The growth of riparian vegetation and the correlation to solar transmission during different phenological phases are measured periodically with radiation sensors. LAI is investigated using hemispherical photographs. Analysis is done with the software Hemiview and Gap Light Analyser (GLA). Results show discrepancies between analysis with the software programs and measurements. Altogether, the variability and the trends of both are similar: the same daily and annual changes can be seen.

Studies on fertilizing process of multi-maleparents of poplar using 3H-labelled nucleic acids

International Nuclear Information System (INIS)

Han Yifan; Du Shengming; Pang Guangchang

1986-01-01

P. Poplar is a hybrib by crossing P. simonii with P. pyramisaliz and Salix matsudana. The hybrid is highly toleant to infertile and soil. In this experiment the second male parent (Salix matsudana) was labelled by 3 H-thymidine and 3 H-adenosine to study its function in fertilization process. The results showed the nucleic acid of Salix matsudana has entered into the fertilized embryo sac, as shown by the silver spots on the radiogaraphs of paraffin section from embryo sac 5-8 days after pollination. The radiation intensity of the hybrid seeds of Salix matsudana labelled with 3 H-A+ 3 H-T as male parent was about two times higher than that of the background and also higher than that of the controls. The more important character was that the trunk color and the winter-bud of P. poplar were similar to those of Salix matsutana. In conclusion, not only the nucleic acids of Salix matsudana entered into the fertilized egg, but also some characters of salix matsudana in the hybrid

Salix purpurea Stimulates the Expression of Specific Bacterial Xenobiotic Degradation Genes in a Soil Contaminated with Hydrocarbons.

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Antoine P Pagé

Full Text Available The objectives of this study were to uncover Salix purpurea-microbe xenobiotic degradation systems that could be harnessed in rhizoremediation, and to identify microorganisms that are likely involved in these partnerships. To do so, we tested S. purpurea's ability to stimulate the expression of 10 marker microbial oxygenase genes in a soil contaminated with hydrocarbons. In what appeared to be a detoxification rhizosphere effect, transcripts encoding for alkane 1-monooxygenases, cytochrome P450 monooxygenases, laccase/polyphenol oxidases, and biphenyl 2,3-dioxygenase small subunits were significantly more abundant in the vicinity of the plant's roots than in bulk soil. This gene expression induction is consistent with willows' known rhizoremediation capabilities, and suggests the existence of S. purpurea-microbe systems that target many organic contaminants of interest (i.e. C4-C16 alkanes, fluoranthene, anthracene, benzo(apyrene, biphenyl, polychlorinated biphenyls. An enhanced expression of the 4 genes was also observed within the bacterial orders Actinomycetales, Rhodospirillales, Burkholderiales, Alteromonadales, Solirubrobacterales, Caulobacterales, and Rhizobiales, which suggest that members of these taxa are active participants in the exposed partnerships. Although the expression of the other 6 marker genes did not appear to be stimulated by the plant at the community level, signs of additional systems that rest on their expression by members of the orders Solirubrobacterales, Sphingomonadales, Actinomycetales, and Sphingobacteriales were observed. Our study presents the first transcriptomics-based identification of microbes whose xenobiotic degradation activity in soil appears stimulated by a plant. It paints a portrait that contrasts with the current views on these consortia's composition, and opens the door for the development of laboratory test models geared towards the identification of root exudate characteristics that limit the

Nutrient Concentrations of Bush Bean (Phaseolus vulgaris L. and Potato (Solanum tuberosum L. Cultivated in Subarctic Soils Managed with Intercropping and Willow (Salix spp. Agroforestry

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Meaghan J. Wilton

2017-12-01

Full Text Available To ease food insecurities in northern Canada, some remote communities started gardening initiatives to gain more access to locally grown foods. Bush beans (Phaseolus vulgaris L. and potatoes (Solanum tuberosum L. were assessed for N, P, K, Mg, and Ca concentrations of foliage as indicators of plant nutrition in a calcareous silty loam soil of northern Ontario James Bay lowlands. Crops were grown in sole cropping and intercropping configurations, with comparisons made between an open field and an agroforestry site enclosed with willow (Salix spp. trees. Foliage chemical analysis of the sites revealed an abundance of Ca, adequacies for Mg and N, and deficiencies in P and K. Intercropping bean and potato did not show significant crop–crop facilitation for nutrients. The agroforestry site showed to be a superior management practice for the James Bay lowland region, specifically for P. The agroforestry site had significantly greater P for bean plant (p = 0.024 and potato foliage (p = 0.002 compared to the open site. It is suspected that the presence of willows improve plant available P to bean and potatoes by tree root—crop root interactions and microclimate enhancements.

Comparative physiological and proteomic analyses of poplar (Populus yunnanensis plantlets exposed to high temperature and drought.

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Xiong Li

Full Text Available Plantlets of Populus yunnanensis Dode were examined in a greenhouse for 48 h to analyze their physiological and proteomic responses to sustained heat, drought, and combined heat and drought. Compared with the application of a single stress, simultaneous treatment with both stresses damaged the plantlets more heavily. The plantlets experienced two apparent response stages under sustained heat and drought. During the first stage, malondialdehyde and reactive oxygen species (ROS contents were induced by heat, but many protective substances, including antioxidant enzymes, proline, abscisic acid (ABA, dehydrin, and small heat shock proteins (sHSPs, were also stimulated. The plants thus actively defended themselves against stress and exhibited few pathological morphological features, most likely because a new cellular homeostasis was established through the collaborative operation of physiological and proteomic responses. During the second stage, ROS homeostasis was overwhelmed by substantial ROS production and a sharp decline in antioxidant enzyme activities, while the synthesis of some protective elements, such as proline and ABA, was suppressed. As a result, photosynthetic levels in P. yunnanensis decreased sharply and buds began to die, despite continued accumulation of sHSPs and dehydrin. This study supplies important information about the effects of extreme abiotic environments on woody plants.

Eucalyptus and Populus short rotation woody crops for phosphate mined lands in Florida USA

Energy Technology Data Exchange (ETDEWEB)

Rockwood, D L; Carter, D R; Langholtz, M H [The School of Forest Resources and Conservation, University of Florida, Box 110410, Gainesville, FL 32611 0410 (United States); Stricker, J A [Polk County Extension Service, University of Florida, Gainesville, FL 32611 (United States)

2006-08-15

Our short-rotation woody crops (SRWC) research in central and southern Florida is (1) developing superior Eucalyptus grandis (EG), E. amplifolia (EA), and cottonwood (Populus deltoides, PD) genotypes, (2) determining appropriate management practices for and associated productivities of these genotypes, and (3) assessing their economics and markets. Reclaimed clay settling areas (CSA) and overburden sites in phosphate mined areas in central Florida are a potential land base of over 80,000ha for SRWC production. On CSAs, PD grows well in the absence of cogongrass (Imperata cylindrica) but is not as productive as the non-invasive EG and EA. SRWC establishment on CSAs requires strict implementation of the following cultural practices: thorough site preparation through herbiciding/disking and bedding, superior trees, watering/packing seedlings, fertilization with ammonium nitrate at planting and annually thereafter as feasible, high planting density possibly including double row planting, and winter harvesting so that coppice regeneration suppresses weeds. PD cultural requirements, that may require post-planting weed control to suppress herbaceous competition, exceed those of the eucalypts. EG SRWCs on CSAs are at risk of blowdown 3-4 years after planting or coppicing; younger PD, EG, and EA SRWCs appear much less susceptible to wind damage. Genetic improvement must continue if EG, EA, and PD are to increase in commercial feasibility. SRWC cost competitiveness will depend on establishment success, yield improvements, harvesting costs, and identifying/using incentives. Strong collaboration among public and private partners is necessary for commercializing SRWCs in Florida. (author)

Sex- and habitat-specific responses of a high arctic willow, Salix arctica, to experimental climate change

Energy Technology Data Exchange (ETDEWEB)

Jones, M.H.; Macdonald, S.E. [Univ. of Alberta, Dept. of Renewable Resources, Edmonton, AB (Canada); Henry, G.H.R. [Univ. of British Columbia, Dept. of Geography, Vancouver, BC (Canada)

1999-10-01

Dioecious plant species and those occupying diverse habitats may present special analytical problems to researchers examining effects of climate change. Here we report the results from two complementary studies designed to determine the importance of sex and habitat on gas exchange and growth of male and female individuals of a dioecious, circumpolar willow, Salix arctica, in the Canadian High Arctic. In field studies, male and female willows from dry and wet habitats were subjected to passively enhanced summer temperature ({approx} to 1.3 deg C) using small open-top chambers over three years. Peak season gas exchange varied significantly by willow sex and habitat. Overall net assimilation was higher in the dry habitat than in the wet, and higher in females than in males. In the dry habitat, net assimilation of females was enhanced by experimental warming, but decreased in males. In the wet habitat, net assimilation of females was substantially depressed by experimental warming, while males showed an inconsistent response. Development and growth of male and female catkins were enhanced by elevated temperature more than leaf fascicles, but leaf fascicle development and growth varied more between the two habitats, particularly in males. In a controlled environment study, male and female willows from these same wet and dry habitats were grown in a 2x2 factorial experiment including 1 x or 2 x ambient [CO{sub 2}] and 5 or 12 deg. C. The sexes responded very differently to the experimental treatments, but we found no effect of original habitat. Net assimilation in males was affected by the interaction of temperature and CO{sub 2}, but in females by CO{sub 2} only. Our results demonstrate (a) significant intraspecific and intersexual differences in arctic willow physiology and growth, (b) that these differences are affected by environmental conditions expected to accompany global climate change, and (c) that sex- and habitat-specific responses should be explicitly

Experimental Salix shoot and root growth statistics on the alluvial sediment of a restored river corridor

Science.gov (United States)

Pasquale, N.; Perona, P.; Verones, F.; Francis, R.; Burlando, P.

2009-12-01

River restoration projects encompass not only the amelioration of flood protection but also the rehabilitation of the riverine ecosystem. However, the interactions and feedbacks between river hydrology, riparian vegetation and aquifer dynamics are still poorly understood. Vegetation interacts with river hydrology on multiple time scales. Hence, there is considerable interest in understanding the morphodynamics of restored river reaches in relation to the characteristics of vegetation that may colonize the bare sediment, and locally stabilize it by root anchoring. In this paper we document results from a number of ongoing experiments within the project RECORD (Restored CORridor Dynamics, sponsored by CCES - www.cces.ch - and Cantons Zurich and Thurgau, CH). In particular, we discuss both the above and below ground biomass growth dynamics of 1188 Salix cuttings (individual and group survival rate, growth of the longest shoots and number of branches and morphological root analysis) in relation to local river hydrodynamics. Cuttings were organized in square plots of different size and planted in spring 2009 on a gravel island of the restored river section of River Thur in Switzerland. By periodical monitoring the plots we obtained a detailed and quite unique set of data, including root statistics of uprooted samples derived from image analysis from a high-resolution scanner. Beyond describing the survival rate dynamics in relation to river hydrology, we show the nature and strength of correlations between island topography and cutting growth statistics. In particular, by root analysis and by comparing empirical histograms of the vertical root distribution vs satured water surface in the sediment, we show that main tropic responses on such environment are oxytropism, hydrotropism and thigmotropism. The main factor influencing the survival rate is naturally found in erosion by floods, of which we also give an interesting example that helps demonstrate the role of river

REQUERIMENTO EM FRIO, DINÂMICA E HETEROGENEIDADE DE DORMÊNCIA DE GEMAS EM RAMOS DE Salix x rubens CULTIVADO EM LAGES, SC

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Tássio Dresch Rech

2006-09-01

Full Text Available A intensidade de dormência e o requerimento em frio do vimeiro (Salix x rubens Shrank foram avaliados pelo método de estacas de gema isolada. As observações foram realizadas em ramos coletados em Lages, SC, a intervalos regulares de 21 dias, de 29/03/2004 a 2/08/2004. A brotação de gemas dos segmentos basal, mediano e distal de ramos do ano foi avaliada na ausência ou após suplementação de frio (500 ou de 1000 horas a 5  3ºC. A brotação de gemas foi avaliada nos estádios: a gemas inchadas; b início da abertura das gemas; c broto alongado e; d broto alongado com folha aberta. A intensidade de dormência das gemas foi crescente da base para a ponta dos ramos e foi máxima em 10 de maio, para todas as regiões do ramo. O tratamento com 500 horas de frio foi efetivo em reduzir o tempo para a brotação, em todas as épocas e posições das gemas no ramo. A avaliação até o aparecimento de folhas abertas foi importante para identificar a real capacidade de brotação das gemas.

Pectin methyl esterase inhibits intrusive and symplastic cell growth in developing wood cells of Populus.

Science.gov (United States)

Siedlecka, Anna; Wiklund, Susanne; Péronne, Marie-Amélie; Micheli, Fabienne; Lesniewska, Joanna; Sethson, Ingmar; Edlund, Ulf; Richard, Luc; Sundberg, Björn; Mellerowicz, Ewa J

2008-02-01

Wood cells, unlike most other cells in plants, grow by a unique combination of intrusive and symplastic growth. Fibers grow in diameter by diffuse symplastic growth, but they elongate solely by intrusive apical growth penetrating the pectin-rich middle lamella that cements neighboring cells together. In contrast, vessel elements grow in diameter by a combination of intrusive and symplastic growth. We demonstrate that an abundant pectin methyl esterase (PME; EC 3.1.1.11) from wood-forming tissues of hybrid aspen (Populus tremula x tremuloides) acts as a negative regulator of both symplastic and intrusive growth of developing wood cells. When PttPME1 expression was up- and down-regulated in transgenic aspen trees, the PME activity in wood-forming tissues was correspondingly altered. PME removes methyl ester groups from homogalacturonan (HG) and transgenic trees had modified HG methylesterification patterns, as demonstrated by two-dimensional nuclear magnetic resonance and immunostaining using PAM1 and LM7 antibodies. In situ distributions of PAM1 and LM7 epitopes revealed changes in pectin methylesterification in transgenic trees that were specifically localized in expanding wood cells. The results show that en block deesterification of HG by PttPME1 inhibits both symplastic growth and intrusive growth. PttPME1 is therefore involved in mechanisms determining fiber width and length in the wood of aspen trees.

Wood properties of Populus and Betula in long-term exposure to elevated CO₂ and O₃.

Science.gov (United States)

Kostiainen, Katri; Saranpää, Pekka; Lundqvist, Sven-Olof; Kubiske, Mark E; Vapaavuori, Elina

2014-06-01

We studied the interactive effects of elevated concentrations of CO2 and O3 on radial growth and wood properties of four trembling aspen (Populus tremuloides Michx.) clones and paper birch (Betula papyrifera Marsh.) saplings. The material for the study was collected from the Aspen FACE (free-air CO2 enrichment) experiment in Rhinelander (WI, USA). Trees had been exposed to four treatments [control, elevated CO2 (560 ppm), elevated O3 (1.5 times ambient) and combined CO2 + O3 ] during growing seasons 1998-2008. Most treatment responses were observed in the early phase of experiment. Our results show that the CO2- and O3-exposed aspen trees displayed a differential balance between efficiency and safety of water transport. Under elevated CO2, radial growth was enhanced and the trees had fewer but hydraulically more efficient larger diameter vessels. In contrast, elevated O3 decreased radial growth and the diameters of vessels and fibres. Clone-specific decrease in wood density and cell wall thickness was observed under elevated CO2 . In birch, the treatments had no major impacts on wood anatomy or wood density. Our study indicates that short-term impact studies conducted with young seedlings may not give a realistic view of long-term ecosystem responses. © 2013 John Wiley & Sons Ltd.

Analysis of genetic diversity in female, male and half sibs willow ...

African Journals Online (AJOL)

The genetic diversity among genotypes of Salix sp. was found to be high, suggesting the importance and feasibility of introducing elite genotypes from different origins for Salix germplasm conservation and breeding programs. Keywords: Salix sp., half sibs, molecular markers, genomic DNA fingerprinting. African Journal of ...

Yield Mapping in Salix; Skoerdekartering av salix

Energy Technology Data Exchange (ETDEWEB)

Anderson, Christoffer; Gilbertsson, Mikael; Rogstrand, Gustav; Thylen, Lars

2004-09-01

The most common species for energy forest production is willow. Willow is able to produce a large amount of biomass in a short period of time. Growing willow has a potential to render a good financial result for the farmer if cultivated on fields with the right conditions and plenty of water. Under the right conditions growing willow can give the farmer a net income of 3,000 SEK (about 430 USD) per hectare and year, which is something that common cereal crops cannot compete with. However, this is not the common case since willow is often grown as a substitute crop on fields where cereal crop yield is low. The aim of this study was to reveal if it is possible to measure yield variability in willow, and if it is possible to describe the reasons for yield variation both within the field but also between different fields. Yield mapping has been used in conventional farming for about a decade. The principles for yield mapping are to continuously measure the yield while registering location by the use of GPS when harvesting the field. The collected data is then used to search for spatial variations within the field, and to try to understand the reasons for this variation. Since there is currently no commercial equipment for yield mapping in willow, a yield mapping system had to be developed within this project. The new system was installed on a Claas Jaguar harvester. The principle for yield mapping on the Claas Jaguar harvester is to measure the distance between the feeding rollers. This distance is correlated to the flow through the harvester. The speed and position of the machine was registered using GPS. Knowing the working width of the harvester this information was used to calculate the yield. All collected data was stored on a PDA computer. Soil samples were also collected from the yield mapped fields. This was to be able to test yield against both physical and chemical soil parameters. The result shows that it is possible to measure spatial variations of yield in willow. It is also possible to measure variations between fields. From the physical and chemical parameters in the soil it is difficult to get a decisive picture of which parameters actually have an effect on the yield, especially if you look at one parameter at time. It is often the interplay between many parameters that results in yield variability. One thing that is evident is that if one parameter is critically low or high, for example extremely dry soil, it effects the yield negatively. Because of problems with the equipment, data could only be collected from five fields in order to make this analysis.

The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

Energy Technology Data Exchange (ETDEWEB)

Wuytack, Tatiana, E-mail: tatiana.wuytack@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Wuyts, Karen, E-mail: karen.wuyts@ugent.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Van Dongen, Stefan, E-mail: stefan.vandongen@ua.ac.be [Department of Biology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Baeten, Lander, E-mail: lander.baeten@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode (Melle) (Belgium); Kardel, Fatemeh, E-mail: fatemeh.kardel@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Verheyen, Kris, E-mail: kris.verheyen@ugent.be [Laboratory of Forestry, Department of Forest and Water Management, Ghent University, Geraardsbergsesteenweg 267, B-9090 Gontrode, Melle (Belgium); Samson, Roeland, E-mail: roeland.samson@ua.ac.be [Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

2011-10-15

We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO{sub x} and O{sub 3} concentrations had only a marginal influence. The influence of SO{sub 2} concentration was negligible. Although our data analysis suggests a relationship between SLA and NO{sub x}/O{sub 3} concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: > Leaf characteristics of white willow as possible bio-indicators for air quality. > Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. > Shadow increases specific leaf area. > NO{sub x} and O{sub 3} change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NO{sub x} and decreasing O{sub 3} concentration, while leaf asymmetry did not respond to air pollution

The effect of air pollution and other environmental stressors on leaf fluctuating asymmetry and specific leaf area of Salix alba L

International Nuclear Information System (INIS)

Wuytack, Tatiana; Wuyts, Karen; Van Dongen, Stefan; Baeten, Lander; Kardel, Fatemeh; Verheyen, Kris; Samson, Roeland

2011-01-01

We aimed at evaluating the effect of low-level air pollution on leaf area fluctuating asymmetry (FAA) and specific leaf area (SLA) of Salix alba L., taking into account other environmental factors. Cuttings were grown in standardized conditions in the near vicinity of air quality measuring stations in Belgium. Variability of SLA and FAA between measuring stations explained 83% and 7.26%, respectively, of the total variability. FAA was not influenced by air pollution or environmental factors such as shading, herbivory, air temperature and humidity. SLA was increased by an increase in shadow, while NO x and O 3 concentrations had only a marginal influence. The influence of SO 2 concentration was negligible. Although our data analysis suggests a relationship between SLA and NO x /O 3 concentration, the absence of a straightforward relationship between FAA and SLA and air pollution still questions the usefulness of these bio-indicators for monitoring air pollution. - Highlights: → Leaf characteristics of white willow as possible bio-indicators for air quality. → Fluctuating asymmetry is not a good bio-indicator for monitoring the air quality. → Shadow increases specific leaf area. → NO x and O 3 change specific leaf area of white willow. - Specific leaf area of S. alba increased with increasing shade and, in less extent, with increasing NO x and decreasing O 3 concentration, while leaf asymmetry did not respond to air pollution

Ozone uptake (flux) as it relates to ozone-induced foliar symptoms of Prunus serotina and Populus maximowizii x trichocarpa

International Nuclear Information System (INIS)

Orendovici-Best, T.; Skelly, J.M.; Davis, D.D.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E.

2008-01-01

Field studies were conducted during 2003 and 2004 from early June to the end of August, at 20 sites of lower or higher elevation within north-central Pennsylvania, using seedlings of black cherry (Prunus serotina, Ehrh.) and ramets of hybrid poplar (Populus maximowizii x trichocarpa). A linear model was developed to estimate the influence of local environmental conditions on stomatal conductance. The most significant factors explaining stomatal variance were tree species, air temperature, leaf vapor pressure deficit, elevation, and time of day. Overall, environmental factors explained less than 35% of the variation in stomatal conductance. Ozone did not affect gas exchange rates in either poplar or cherry. Ozone-induced foliar injury was positively correlated with cumulative ozone exposures, expressed as SUM40. Overall, the amount of foliar injury was better correlated to a flux-based approach rather than to an exposure-based approach. More severe foliar injuries were observed on plants growing at higher elevations. - Within heterogeneous environments, ozone flux does not completely explain the variation observed in ozone-induced visible injury

Differences in Cd and Zn bioaccumulation for the flood-tolerant Salix cinerea rooting in seasonally flooded contaminated sediments.

Science.gov (United States)

Vandecasteele, Bart; Laing, Gijs Du; Quataert, Paul; Tack, Filip M G

2005-04-01

Several authors suggest that a hydrological regime aiming at wetland creation is a potential management option that favours reducing bioavailability for metal-contaminated sites. The hydrological conditions on a site constitute one of the many factors that may affect the availability of potentially toxic trace metals for uptake by plants. Bioavailability of Cd, Mn and Zn on a contaminated dredged sediment landfill (DSL) with variable duration of submersion was evaluated by measuring metal concentrations in the wetland plant species Salix cinerea in field conditions. Longer submersion periods in the field caused lower Cd and Zn concentrations in the leaves in the first weeks of the growing season. Foliar Cd and Zn concentrations at the end of the growing season were highest on the initially flooded plot that emerged early in the growing season. Foliar Zn concentrations were also high at a sandy-textured oxic plot with low soil metal concentrations. Zn uptake in the leaves was markedly slower than Cd uptake for trees growing on soils with prolonged waterlogging during the growing season, pointing at a different availability. Zn availability was lowest when soil was submerged, but metal transfer from stems and twigs to leaves may mask the lower availability of Cd in submerged soils. Especially for Cd, a transfer effect from one growing season to the next season was observed: oxic conditions at the end of the previous growing season seem to determine at least partly the foliar concentrations for S. cinerea through this metal transfer mechanism. Duration of the submersion period is a key factor for bioavailability inasmuch as initially submerged soils emerging only in the second half of the growing season resulted in elevated Cd and Zn foliar concentrations at that time.

Transcriptome responses to aluminum stress in roots of aspen (Populus tremula

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Grisel Nadine

2010-08-01

Full Text Available Abstract Background Ionic aluminum (mainly Al3+ is rhizotoxic and can be present in acid soils at concentrations high enough to inhibit root growth. Many forest tree species grow naturally in acid soils and often tolerate high concentrations of Al. Previously, we have shown that aspen (Populus tremula releases citrate and oxalate from roots in response to Al exposure. To obtain further insights into the root responses of aspen to Al, we investigated root gene expression at Al conditions that inhibit root growth. Results Treatment of the aspen roots with 500 μM Al induced a strong inhibition of root growth within 6 h of exposure time. The root growth subsequently recovered, reaching growth rates comparable to that of control plants. Changes in gene expression were determined after 6 h, 2 d, and 10 d of Al exposure. Replicated transcriptome analyses using the Affymetrix poplar genome array revealed a total of 175 significantly up-regulated and 69 down-regulated genes, of which 70% could be annotated based on Arabidopsis genome resources. Between 6 h and 2 d, the number of responsive genes strongly decreased from 202 to 26, and then the number of changes remained low. The responses after 6 h were characterized by genes involved in cell wall modification, ion transport, and oxidative stress. Two genes with prolonged induction were closely related to the Arabidopsis Al tolerance genes ALS3 (for Al sensitive 3 and MATE (for multidrug and toxin efflux protein, mediating citrate efflux. Patterns of expression in different plant organs and in response to Al indicated that the two aspen genes are homologs of the Arabidopsis ALS3 and MATE. Conclusion Exposure of aspen roots to Al results in a rapid inhibition of root growth and a large change in root gene expression. The subsequent root growth recovery and the concomitant reduction in the number of responsive genes presumably reflect the success of the roots in activating Al tolerance mechanisms. The

Communities of the alliance Bidenti frondosae-Salicion triandrae Golub 2004 on the territory of the Lower Volga Valley

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V. B. Golub

2010-01-01

Full Text Available Communities of the alliance Bidenti frondosae-Salicion triandrae Golub 2004 – is a shrub communities with dominant Salix triandra и Amorpha fruticosa along the watercourse banks and lakes in the Lower Volga valley. Diagnostis species of alliance: Fraxinus pennsylvanica, Bidens frondosa, Xanthium strumarium, Thalictrum flavum. The alliance is also diagnosed by the absence or non-significant presence of species number, characteristic of communities with dominant Salix triandra on more northern territories, which are supposed to refer to the alliance Salicion triandrae Th. Muller et Gors 1958. There are Salix fragilis, Salix viminalis, Urtica dioica, Galium palustre, Lythrum salicaria, Lysimachia vulgaris. One more peculiarity of communities of alliance Bidenti frondosae-Salicion triandrae should be noted. It lies in the fact that Salix triamdra in the Lower Volga is represented by lately flowering ecotype. Salix triamdra blooms here after the water abatement in June-Jule. It is 2-3 months later that in other river flood-plains characterized by Salix triamdra earlier flooding. Communities of the alliance including four accociations: Bidenti frondosae-Salicion triandrae, Leersio-Salicetum triandrae, Carici melanostachyаe-Amorphetum fruticosae, Rubo caesii-Amorphetumfruticosae, which have different stage of widespread in the territory of the Lower Volga.

Scientific Basis for Sustainable Management of Eucalyptus and Populus as Short-Rotation Woody Crops in the U.S.

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Eric D. Vance

2014-05-01

Full Text Available Short rotation woody crops (SRWC, fast growing tree species that are harvested on short, repeated intervals, can augment traditional fiber sources. These crops have economic and environmental benefits stemming from their capability of supplying fiber on a reduced land base in close proximity to users and when sensitive sites cannot be accessed. Eucalyptus and Populus appear to be genera with the greatest potential to provide supplemental fiber in the U.S. Optimal productivity can be achieved through practices that overcome site limitations and by choosing the most appropriate sites, species, and clones. Some Eucalyptus species are potentially invasive, yet field studies across multiple continents suggest they are slower to disperse than predicted by risk assessments. Some studies have found lower plant and animal diversity in SRWC systems compared to mature, native forests, but greater than some alterative land uses and strongly influenced by stand management, land use history, and landscape context. Eucalyptus established in place of grasslands, arable lands, and, in some cases, native forests can reduce streamflow and lower water tables due to higher interception and transpiration rates but results vary widely, are scale dependent, and are most evident in drier regions.

Nitrogen nutrient status induces sexual differences in responses to cadmium in Populus yunnanensis.

Science.gov (United States)

Chen, Lianghua; Han, Ying; Jiang, Hao; Korpelainen, Helena; Li, Chunyang

2011-10-01

Populus yunnanensis was employed as a model species to detect sexual differences in growth, physiological, biochemical, and ultrastructural responses to cadmium (Cd) stress, nitrogen (N) deposition, and their combination. Compared with the control conditions, Cd decreased plant biomass, damaged the photosynthetic apparatus, visible as a decreased maximum efficiency of photosystem II (PSII; F(v)/F(m)) and effective quantum yield of PSII (Yield), depressed gas exchange capacity, and induced oxidative stress, visible as the disruption of antioxidative enzymes and accumulation of reactive oxygen species (ROS), in both sexes. On the other hand, Cd toxicity was mitigated by the recovery of gas exchange capacity, a decrease in ROS, and improvement of the redox imbalance in both sexes when N deposition was applied. However, males showed a higher gas exchange capacity, lower enzyme inhibition and ROS accumulation, stronger abilities to maintain cellular redox homeostasis, and a better maintenance of chloroplast ultrastructure than did females when exposed to Cd stress alone. Although males exhibited a higher Cd content in leaves than did females, males also accumulated higher levels of non-protein thiols (NP-SHs) and free amino acids (FAAs) for detoxification than did females. Sexual differences induced by Cd, visible, for example, in F(v)/F(m), Yield, net photosynthesis rate (A), and stomatal conductance (g(s)), decreased under N deposition, as no significant differences between the sexes existed in these parameters under the combined treatment. The results indicated that females are more sensitive to Cd stress and suffer more injuries than do males. Moreover, N deposition can mitigate Cd toxicity and decrease sexual differences in Cd sensitivity.

Dicty_cDB: Contig-U03072-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available verselong Onychiurus arcticus d... 38 0.010 2 ( CF439672 ) EST676017 normalized cDNA library of ...ornis cDN... 68 8e-07 1 ( BU884919 ) R017H10 Populus root cDNA library Populus tremula... 68 8e-07 1 ( ...us dormant bud cDNA library Populus ... 60 2e-04 1 ( CK110478 ) N067A08 Populus bark cDNA library Populus tremul...04 1 ( BU887484 ) R062A08 Populus root cDNA library Populus tremula... 60 2e-04 1 ( BU880608 ) UM52TC12 Populus flower cDNA library...us tremula cambium cDNA library Po... 60 2e-04 1 ( BU819297 ) UA42BPA08 Populus tremula cambium cDNA library

Energy dynamics in Populus deltoides G{sub 3} Marsh agroforestry systems in eastern India

Energy Technology Data Exchange (ETDEWEB)

Chaturvedi, O.P. [National Research Centre for Agroforestry, Jhansi (India); Das, D.K. [Rajendra Agricultural Univ., Dept. of Forestry, Bihar (India)

2005-08-01

Energy efficiency of Populus deltoides G{sub 3} Marsh agroforestry of a 3-year-old system with intercropping of maize-wheat in crop I and pigeonpea in crop II and of a 9-year-old system with turmeric, a shade loving crop was studied at Pusa, Bihar in eastern India. Energy fixation, storage, net allocation in agronomic yield and energy released and exit from the 9-year-old system was 1.53, 4.30, 0.43 and 3.37 times in crop I and 1.67, 4.60, 0.53 and 3.30 times in crop II of the 3-year-old agroforestry system. The energy conservation efficiency in the 9-year-old system was higher (1.91%) as compared to crop I (1.24%) and crop II (1.15%) of the 3-year-old agroforestry system. The energy accumulation ratio in the 9-year-old system was 2.82 and 2.77 times higher in crop I and crop II, respectively, of the 3-year-old agroforestry system. The 3-year-old agroforestry system showed lower energy accumulation ratio resulting from less energy accumulation in perennial turnover in the form of leaf of tree and agricultural crops. The crop II system of the 3-year-old poplar agroforestry was more efficient system of management due to higher quanta of energy and higher cash return but one has to opt for shade loving intercrop turmeric with increase in age of the poplar plantation and more canopy closure. (Author)

Genetic, morphological, and spectral characterization of relictual Niobrara River hybrid aspens (Populus × smithii).

Science.gov (United States)

Deacon, Nicholas John; Grossman, Jake Joseph; Schweiger, Anna Katharina; Armour, Isabella; Cavender-Bares, Jeannine

2017-12-01

Aspen groves along the Niobrara River in Nebraska have long been a biogeographic curiosity due to morphological differences from nearby remnant Populus tremuloides populations. Pleistocene hybridization between P. tremuloides and P. grandidentata has been proposed, but the nearest P. grandidentata populations are currently several hundred kilometers east. We tested the hybrid-origin hypothesis using genetic data and characterized putative hybrids phenotypically. We compared nuclear microsatellite loci and chloroplast sequences of Niobrara River aspens to their putative parental species. Parental species and putative hybrids were also grown in a common garden for phenotypic comparison. On the common garden plants, we measured leaf morphological traits and leaf-level spectral reflectance profiles, from which chemical traits were derived. The genetic composition of the three unique Niobrara aspen genotypes is consistent with the hybridization hypothesis and with maternal chloroplast inheritance from P. grandidentata . Leaf margin dentition and abaxial pubescence differentiated taxa, with the hybrids showing intermediate values. Spectral profiles allowed statistical separation of taxa in short-wave infrared wavelengths, with hybrids showing intermediate values, indicating that traits associated with internal structure of leaves and water absorption may vary among taxa. However, reflectance values in the visible region did not differentiate taxa, indicating that traits related to pigments are not differentiated. Both genetic and phenotypic results support the hypothesis of a hybrid origin for these genetically unique aspens. However, low genetic diversity and ongoing ecological and climatic threats to the hybrid taxon present a challenge for conservation of these relictual boreal communities. © 2017 Botanical Society of America.

Comparative Physiological and Proteomic Analysis Reveals the Leaf Response to Cadmium-Induced Stress in Poplar (Populus yunnanensis.

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Yunqiang Yang

Full Text Available Excess amounts of heavy metals are important environmental pollutants with significant ecological and nutritional effects. Cdmium (Cd is of particular concern because of its widespread occurrence and high toxicity. We conducted physiological and proteomic analyses to improve our understanding of the responses of Populus yunnanensis to Cd stress. The plantlets experienced two apparent stages in their response to Cd stress. During the first stage, transiently induced defense-response molecules, photosynthesis- and energy-associated proteins, antioxidant enzymes and heat shock proteins (HSPs accumulated to enhance protein stability and establish a new cellular homeostasis. This activity explains why plant photosynthetic capability during this period barely changed. During the second stage, a decline of ribulose-1, 5-bisphosphate carboxylase (RuBisCO and HSP levels led to imbalance of the plant photosynthetic system. Additionally, the expression of Mitogen-activated protein kinase 3 (MPK3, Mitogen-activated protein kinase 6 (MPK6 and a homeobox-leucine zipper protein was higher in the second stage. Higher expression of caffeoyl-CoA O-methyltransferase (CCoAOMT may regulate plant cell wall synthesis for greater Cd storage. These genes may be candidates for further research and use in genetic manipulation of poplar tolerance to Cd stress.

Dying piece by piece: carbohydrate dynamics in aspen (Populus tremuloides) seedlings under severe carbon stress.

Science.gov (United States)

Wiley, Erin; Hoch, Günter; Landhäusser, Simon M

2017-11-02

Carbon starvation as a mechanism of tree mortality is poorly understood. We exposed seedlings of aspen (Populus tremuloides) to complete darkness at 20 or 28 °C to identify minimum non-structural carbohydrate (NSC) concentrations at which trees die and to see if these levels vary between organs or with environmental conditions. We also first grew seedlings under different shade levels to determine if size affects survival time under darkness due to changes in initial NSC concentration and pool size and/or respiration rates. Darkness treatments caused a gradual dieback of tissues. Even after half the stem had died, substantial starch reserves were still present in the roots (1.3-3% dry weight), indicating limitations to carbohydrate remobilization and/or transport during starvation in the absence of water stress. Survival time decreased with increased temperature and with increasing initial shade level, which was associated with smaller biomass, higher respiration rates, and initially smaller NSC pool size. Dead tissues generally contained no starch, but sugar concentrations were substantially above zero and differed between organs (~2% in stems up to ~7.5% in leaves) and, at times, between temperature treatments and initial, pre-darkness shade treatments. Minimum root NSC concentrations were difficult to determine because dead roots quickly began to decompose, but we identify 5-6% sugar as a potential threshold for living roots. This variability may complicate efforts to identify critical NSC thresholds below which trees starve. © Society for Experimental Biology 2017.

The genetic architecture of shoot-root covariation during seedling emergence of a desert tree, Populus euphratica.

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Zhang, Miaomiao; Bo, Wenhao; Xu, Fang; Li, Huan; Ye, Meixia; Jiang, Libo; Shi, Chaozhong; Fu, Yaru; Zhao, Guomiao; Huang, Yuejiao; Gosik, Kirk; Liang, Dan; Wu, Rongling

2017-06-01

The coordination of shoots and roots is critical for plants to adapt to changing environments by fine-tuning energy production in leaves and the availability of water and nutrients from roots. To understand the genetic architecture of how these two organs covary during developmental ontogeny, we conducted a mapping experiment using Euphrates poplar (Populus euphratica), a so-called hero tree able to grow in the desert. We geminated intraspecific F 1 seeds of Euphrates Poplar individually in a tube to obtain a total of 370 seedlings, whose shoot and taproot lengths were measured repeatedly during the early stage of growth. By fitting a growth equation, we estimated asymptotic growth, relative growth rate, the timing of inflection point and duration of linear growth for both shoot and taproot growth. Treating these heterochronic parameters as phenotypes, a univariate mapping model detected 19 heterochronic quantitative trait loci (hQTLs), of which 15 mediate the forms of shoot growth and four mediate taproot growth. A bivariate mapping model identified 11 pleiotropic hQTLs that determine the covariation of shoot and taproot growth. Most QTLs detected reside within the region of candidate genes with various functions, thus confirming their roles in the biochemical processes underlying plant growth. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Flow regime effects on mature Populus fremontii (Fremont cottonwood) productivity on two contrasting dryland river floodplains

Science.gov (United States)

Andersen, Douglas C.

2016-01-01

I compared riparian cottonwood (Populus fremontii) productivity-discharge relationships in a relictual stand along the highly regulated Green River and in a naturally functioning stand along the unregulated Yampa River in semiarid northwest Colorado. I used multiple regression to model flow effects on annual basal area increment (BAI) from 1982 to 2011, after removing any autocorrelation present. Each BAI series was developed from 20 trees whose mean size (67 cm diameter at breast height [DBH]) was equivalent in the two stands. BAI was larger in the Yampa River stand except in 2 y when defoliating leaf beetles were present there. I found no evidence for a Yampa flood-magnitude threshold above which BAI declined. Flow variables explained ∼45% of residual BAI variability, with most explained by current-year maximum 90-d discharge (QM90) in the Yampa River stand and by a measure of the year-to-year change in QM90 in the Green River stand. The latter reflects a management-imposed ceiling on flood magnitude—Flaming Gorge Dam power plant capacity—infrequently exceeded during the study period. BAI in the relictual stand began to trend upward in 1992 when flows started to mimic a natural flow regime. Mature Fremont cottonwoods appear to be ecologically resilient. Their productivity along regulated rivers might be optimized using multiyear environmental flow designs.

Lead tolerance of Populus nigra in symbiosis with arbuscular mycorrhizal fungi in relation to physiological parameters

International Nuclear Information System (INIS)

Salehi, A.; Tabari, M.; Mohammadi Goltapeh, E.; Shirvani, A.

2016-01-01

With the aim to examine lead tolerance of Populus nigra (clone 62/154) in symbiosis witharbuscular mycorrhizal fungi, a greenhouse experiment was carried out in a factorial randomized complete scheme with two factors 1) fungal inoculation in 4 levels (control, inoculation with Glomus mosseae, inoculation with G. intraradices and inoculation with G. mosseae+G. intraradices) and 2) lead in 4 levels (0, 100, 500 and 1000 mg kg-1 soil). Mycorrhizal colonization and physiological parameters of plants were measured at the end of growth season. Results showed that at all Pb levels, the percentage of root mycorrhizal colonization in fungal treatments was significantly higher than that in control treatment (without fungal inoculation), however without significant differences between 3 fungal treatments. Pb treatments had no significant effect on root mycorrhizal colonization of P. nigra plants. Also, photosynthesis, stomatal conductance, transpiration, intercellular CO2 concentration and water use efficiency of P. nigra plants had no significant inhibitory effects versus the control found under Pb and fungal treatments or their interaction.The results of present study demonstrated that fungal treatments had no significant effects on physiological parameters and Pb tolerance of P. nigraplants. While, in relation to mycorrhizal colonization and physiological parameters, P. nigra clone 62/154 showeda good tolerance to Pb stress. So, in further investigations of phytoremediation of lead-contaminated soils, this clone can be considered as a proposed species.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

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Nie, Shaobo [Department of Orthopaedics, PLA General Hospital, Beijing 100853 (China); Xu, Jiawei [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Zhang, Chenghua [Department of Orthopaedics, Changle County Hospital of Traditional Chinese Medicine, Weifang 262400 (China); Xu, Chen [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Liu, Ming, E-mail: ming_li4717@sina.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China); Yu, Degang, E-mail: ydg163@126.com [Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011 (China)

2016-01-29

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Climate-resilient agroforestry: physiological responses to climate change and engineering of crassulacean acid metabolism (CAM) as a mitigation strategy.

Science.gov (United States)

Borland, Anne M; Wullschleger, Stan D; Weston, David J; Hartwell, James; Tuskan, Gerald A; Yang, Xiaohan; Cushman, John C

2015-09-01

Global climate change threatens the sustainability of agriculture and agroforestry worldwide through increased heat, drought, surface evaporation and associated soil drying. Exposure of crops and forests to warmer and drier environments will increase leaf:air water vapour-pressure deficits (VPD), and will result in increased drought susceptibility and reduced productivity, not only in arid regions but also in tropical regions with seasonal dry periods. Fast-growing, short-rotation forestry (SRF) bioenergy crops such as poplar (Populus spp.) and willow (Salix spp.) are particularly susceptible to hydraulic failure following drought stress due to their isohydric nature and relatively high stomatal conductance. One approach to sustaining plant productivity is to improve water-use efficiency (WUE) by engineering crassulacean acid metabolism (CAM) into C3 crops. CAM improves WUE by shifting stomatal opening and primary CO2 uptake and fixation to the night-time when leaf:air VPD is low. CAM members of the tree genus Clusia exemplify the compatibility of CAM performance within tree species and highlight CAM as a mechanism to conserve water and maintain carbon uptake during drought conditions. The introduction of bioengineered CAM into SRF bioenergy trees is a potentially viable path to sustaining agroforestry production systems in the face of a globally changing climate. © 2014 John Wiley & Sons Ltd.

Salicortin inhibits osteoclast differentiation and bone resorption by down-regulating JNK and NF-κB/NFATc1 signaling pathways

International Nuclear Information System (INIS)

Nie, Shaobo; Xu, Jiawei; Zhang, Chenghua; Xu, Chen; Liu, Ming; Yu, Degang

2016-01-01

Receptor activator of nuclear factor (NF)-κB ligand (RANKL)-activated signaling is essential for osteoclast differentiation, activation, and survival. Salicortin is a phenolic glycoside that has been isolated from many plants such as Populus and Salix species, and has been shown to have anti-amnesic and anti-adipogenic effects. In this study, we investigated the effect of salicortin on RANKL-induced osteoclasts formation, bone resorption, and activation of osteoclast-related signaling pathways. Salicortin suppressed RANKL-induced osteoclastogenesis in bone marrow macrophage cultures in a dose-dependent manner, and inhibited osteoclastic bone resorption activity without any cytotoxicity. Salicortin inhibited RANKL-induced c-Jun N-terminal kinase and NF-κB activation, concomitant with retarded IκBα phosphorylation and inhibition of p65 nuclear translocation, leading to impaired transcription of nuclear factor of activated T cells c1 (NFATc1) and expression of osteoclastic-specific genes. Taken together, our findings demonstrate that salicortin inhibits NF-κB and NFATc1 activation, leading to attenuation of osteoclastogenesis and bone resorption. Thus, salicortin may be of interest in developments of treatment for osteoclast related diseases. - Highlights: • Salicortin suppresses osteoclastogenesis in vitro. • Salicortin impairs the JNK and NF-κB/NFATc1 signaling pathway. • Salicortin may be of interest in developments of osteoporosis treatment.

Phytoremediation trials on metal- and arsenic-contaminated pyrite wastes (Torviscosa, Italy)

Energy Technology Data Exchange (ETDEWEB)

Vamerali, Teofilo [Department of Environmental Sciences, University of Parma, Viale G.P. Usberti 11/A, 43100 Parma (Italy)], E-mail: teofilo.vamerali@unipd.it; Bandiera, Marianna; Coletto, Lucia; Zanetti, Federica [Department of Environmental Agronomy and Crop Sciences, University of Padova, Viale dell' Universita 16, 35020 Legnaro - Padova (Italy); Dickinson, Nicholas M. [Faculty of Science, Liverpool John Moores University, Byrom Street, Liverpool, L3 3AF (United Kingdom); Mosca, Giuliano [Department of Environmental Agronomy and Crop Sciences, University of Padova, Viale dell' Universita 16, 35020 Legnaro - Padova (Italy)

2009-03-15

At a site in Udine, Italy, a 0.7 m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15 m layer of gravelly soil. This study investigates whether woody biomass phytoremediation is a realistic management option. Comparing ploughing and subsoiling (0.35 m depth), the growth of Populus and Salix and trace element uptake were investigated in both pot and field trials. Species differences were marginal and species selection was not critical. Impaired above-ground productivity and low translocation of trace elements showed that bioavailable contaminant stripping was not feasible. The most significant finding was of coarse and fine roots proliferation in surface layers that provided a significant sink for trace elements. We conclude that phytostabilisation and effective immobilisation of metals and As could be achieved at the site by soil amelioration combined with woody species establishment. Confidence to achieve a long-term and sustainable remediation requires a more complete quantification of root dynamics and a better understanding of rhizosphere processes. - In As- and metal-contaminated pyrite wastes, contaminant stripping is not feasible, and root foraging and quantification of root dynamics holds the key to stabilisation in woody species.

Phytoremediation trials on metal- and arsenic-contaminated pyrite wastes (Torviscosa, Italy)

International Nuclear Information System (INIS)

Vamerali, Teofilo; Bandiera, Marianna; Coletto, Lucia; Zanetti, Federica; Dickinson, Nicholas M.; Mosca, Giuliano

2009-01-01

At a site in Udine, Italy, a 0.7 m layer of As, Co, Cu, Pb and Zn contaminated wastes derived from mineral roasting for sulphur extraction had been covered with an unpolluted 0.15 m layer of gravelly soil. This study investigates whether woody biomass phytoremediation is a realistic management option. Comparing ploughing and subsoiling (0.35 m depth), the growth of Populus and Salix and trace element uptake were investigated in both pot and field trials. Species differences were marginal and species selection was not critical. Impaired above-ground productivity and low translocation of trace elements showed that bioavailable contaminant stripping was not feasible. The most significant finding was of coarse and fine roots proliferation in surface layers that provided a significant sink for trace elements. We conclude that phytostabilisation and effective immobilisation of metals and As could be achieved at the site by soil amelioration combined with woody species establishment. Confidence to achieve a long-term and sustainable remediation requires a more complete quantification of root dynamics and a better understanding of rhizosphere processes. - In As- and metal-contaminated pyrite wastes, contaminant stripping is not feasible, and root foraging and quantification of root dynamics holds the key to stabilisation in woody species

Use of atomic absorption spectrometry in assessment of biomonitor plants for lead, cadmium and copper pollution.

Science.gov (United States)

Gokce, Kaya; Mehmet, Yaman

2012-01-01

Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep, Turkey. Lead, cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry. Lead, Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304-602, 0.4-0.44 and 31-37 mg x kg(-1), respectively. Significantly increased lead concentration up to 2 750 mg x kg(-1) was found in the leaves of Eleagnus angustifolia L. plant. The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima > Morus sp. > Juglans regia L. > Ficus carica L. > Cydonia oblonga Miller > Prunus x domestica L. The plants, Populus nigra L. , Eleagnus angustifolia L. and Salix sp. were found useful for Cd, and the plant, Eleagnus angusti folia L. for Pb, to be considered as potential biomonitor. Especially, leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations. Therefore, people who and animals which live in this area and benefit from these soil and plants have vital risks.

Fiber length and pulping characteristics of switchgrass, alfalfa stems, hybrid poplar and willow biomasses.

Science.gov (United States)

Ai, Jun; Tschirner, Ulrike

2010-01-01

Switchgrass (Panicum virgatum), alfalfa stems (Medicago sativa), second year growth hybrid poplar (Populus) and willow (Salix spp.) were examined to determine fiber characteristics, pulping behavior and paper properties. Alfalfa stems and switchgrass both showed length weighted average fiber length (LWW) of 0.78 mm, a very narrow fiber length distribution and high fines content. Willow and hybrid poplar have lower fines content but a very low average fiber length (0.42 and 0.48 mm LWW). In addition, the four biomass species showed distinctly different chemical compositions. Switchgrass was defibered successfully using Soda and Soda Anthraquinone (AQ) pulping and demonstrated good paper properties. Both fast-growing wood species pulped well using the Kraft process, and showed acceptable tensile strength, but low tear strength. Alfalfa stems reacted very poorly to Soda and Soda AQ pulping but responded well to Kraft and Kraft AQ. Pulps with tensile and tear strength considerably higher than those found for commercial aspen pulps were observed for alfalfa. All four biomass species examined demonstrated low pulp yield. The highest yields were obtained with poplar and switchgrass (around 43%). Considering the short fibers and low yields, all four biomass types will likely only be used in paper manufacturing if they offer considerable economic advantage over traditional pulp wood.

The UDP-glucuronate decarboxylase gene family in Populus: structure, expression, and association genetics.

Directory of Open Access Journals (Sweden)

Qingzhang Du

Full Text Available In woody crop plants, the oligosaccharide components of the cell wall are essential for important traits such as bioenergy content, growth, and structural wood properties. UDP-glucuronate decarboxylase (UXS is a key enzyme in the synthesis of UDP-xylose for the formation of xylans during cell wall biosynthesis. Here, we isolated a multigene family of seven members (PtUXS1-7 encoding UXS from Populus tomentosa, the first investigation of UXSs in a tree species. Analysis of gene structure and phylogeny showed that the PtUXS family could be divided into three groups (PtUXS1/4, PtUXS2/5, and PtUXS3/6/7, consistent with the tissue-specific expression patterns of each PtUXS. We further evaluated the functional consequences of nucleotide polymorphisms in PtUXS1. In total, 243 single-nucleotide polymorphisms (SNPs were identified, with a high frequency of SNPs (1/18 bp and nucleotide diversity (πT = 0.01033, θw = 0.01280. Linkage disequilibrium (LD analysis showed that LD did not extend over the entire gene (r (2<0.1, P<0.001, within 700 bp. SNP- and haplotype-based association analysis showed that nine SNPs (Q <0.10 and 12 haplotypes (P<0.05 were significantly associated with growth and wood property traits in the association population (426 individuals, with 2.70% to 12.37% of the phenotypic variation explained. Four significant single-marker associations (Q <0.10 were validated in a linkage mapping population of 1200 individuals. Also, RNA transcript accumulation varies among genotypic classes of SNP10 was further confirmed in the association population. This is the first comprehensive study of the UXS gene family in woody plants, and lays the foundation for genetic improvements of wood properties and growth in trees using genetic engineering or marker-assisted breeding.

Sex-specific responses of Populus yunnanensis exposed to elevated CO{sub 2} and salinity

Energy Technology Data Exchange (ETDEWEB)

Ling Li; Yuanbin Zhang; Chunyang Li [Chinese Academy of Sciences. Chengdu Institute of Biology, Chengdu (Switzerland); Jianxun Luo, Sichuan Academy of Forestry, Chengdu (Switzerland)); Korpelainen, H. [Univ. of Helsinki. Dept. of Agricultural Sciences, Helsinki (Finland)

2013-04-15

Populus yunnanensis Dode., a native dioecious woody plant in southwestern China, was employed as a model species to study sex-specific morphological, physiological and biochemical responses to elevated CO{sub 2} and salinity. To investigate the effects of elevated CO{sub 2}, salinity and their combination, the cuttings were exposed to two CO{sub 2} regimes (ambient CO{sub 2} and double ambient CO{sub 2}) and two salt treatments in growth chambers. Males exhibited greater downregulation of net photosynthesis rate (A{sub net}) and carboxylation efficiency (CE) than females at elevated CO{sub 2}, whereas these sexual differences were lessened under salt stress. On the other hand, salinity induced a higher decrease in Anet and CE, more growth inhibition and leaf Cl{sup -} accumulation and more damage to cell organelles in females than in males, whereas the sexual differences in photosynthesis and growth were lessened at elevated CO{sub 2}. Moreover, elevated CO{sub 2} exacerbated membrane lipid peroxidation and organelle damage in females but not in males under salt stress. Our results indicated that: (1) females are more sensitive and suffer from greater negative effects than do males under salt stress, and elevated CO{sub 2} lessens the sexual differences in photosynthesis and growth under salt stress; (2) elevated CO{sub 2} tends to aggravate the negative effects of salinity in females; and (3) sex-specific reactions under the combination of elevated CO{sub 2} and salinity are distinct from single-stress responses. Therefore, these results provide evidence for different adaptive responses between plants of different sexes exposed to elevated CO{sub 2} and salinity. (Author)

Identifying gene coexpression networks underlying the dynamic regulation of wood-forming tissues in Populus under diverse environmental conditions.

Science.gov (United States)

Zinkgraf, Matthew; Liu, Lijun; Groover, Andrew; Filkov, Vladimir

2017-06-01

Trees modify wood formation through integration of environmental and developmental signals in complex but poorly defined transcriptional networks, allowing trees to produce woody tissues appropriate to diverse environmental conditions. In order to identify relationships among genes expressed during wood formation, we integrated data from new and publically available datasets in Populus. These datasets were generated from woody tissue and include transcriptome profiling, transcription factor binding, DNA accessibility and genome-wide association mapping experiments. Coexpression modules were calculated, each of which contains genes showing similar expression patterns across experimental conditions, genotypes and treatments. Conserved gene coexpression modules (four modules totaling 8398 genes) were identified that were highly preserved across diverse environmental conditions and genetic backgrounds. Functional annotations as well as correlations with specific experimental treatments associated individual conserved modules with distinct biological processes underlying wood formation, such as cell-wall biosynthesis, meristem development and epigenetic pathways. Module genes were also enriched for DNase I hypersensitivity footprints and binding from four transcription factors associated with wood formation. The conserved modules are excellent candidates for modeling core developmental pathways common to wood formation in diverse environments and genotypes, and serve as testbeds for hypothesis generation and testing for future studies. No claim to original US government works. New Phytologist © 2017 New Phytologist Trust.

Ethylene and jasmonic acid act as negative modulators during mutualistic symbiosis between Laccaria bicolor and Populus roots.

Science.gov (United States)

Plett, Jonathan M; Khachane, Amit; Ouassou, Malika; Sundberg, Björn; Kohler, Annegret; Martin, Francis

2014-04-01

The plant hormones ethylene, jasmonic acid and salicylic acid have interconnecting roles during the response of plant tissues to mutualistic and pathogenic symbionts. We used morphological studies of transgenic- or hormone-treated Populus roots as well as whole-genome oligoarrays to examine how these hormones affect root colonization by the mutualistic ectomycorrhizal fungus Laccaria bicolor S238N. We found that genes regulated by ethylene, jasmonic acid and salicylic acid were regulated in the late stages of the interaction between L. bicolor and poplar. Both ethylene and jasmonic acid treatments were found to impede fungal colonization of roots, and this effect was correlated to an increase in the expression of certain transcription factors (e.g. ETHYLENE RESPONSE FACTOR1) and a decrease in the expression of genes associated with microbial perception and cell wall modification. Further, we found that ethylene and jasmonic acid showed extensive transcriptional cross-talk, cross-talk that was opposed by salicylic acid signaling. We conclude that ethylene and jasmonic acid pathways are induced late in the colonization of root tissues in order to limit fungal growth within roots. This induction is probably an adaptive response by the plant such that its growth and vigor are not compromised by the fungus. © 2013 The Authors New Phytologist © 2013 New Phytologist Trust.

Cloning of the cryptochrome-encoding PeCRY1 gene from Populus euphratica and functional analysis in Arabidopsis.

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Ke Mao

Full Text Available Cryptochromes are photolyase-like blue/UV-A light receptors that evolved from photolyases. In plants, cryptochromes regulate various aspects of plant growth and development. Despite of their involvement in the control of important plant traits, however, most studies on cryptochromes have focused on lower plants and herbaceous crops, and no data on cryptochrome function are available for forest trees. In this study, we isolated a cryptochrome gene, PeCRY1, from Euphrates poplar (Populus euphratica, and analyzed its structure and function in detail. The deduced PeCRY1 amino acid sequence contained a conserved N-terminal photolyase-homologous region (PHR domain as well as a C-terminal DQXVP-acidic-STAES (DAS domain. Secondary and tertiary structure analysis showed that PeCRY1 shares high similarity with AtCRY1 from Arabidopsis thaliana. PeCRY1 expression was upregulated at the mRNA level by light. Using heterologous expression in Arabidopsis, we showed that PeCRY1 overexpression rescued the cry1 mutant phenotype. In addition, PeCRY1 overexpression inhibited hypocotyl elongation, promoted root growth, and enhanced anthocyanin accumulation in wild-type background seedlings grown under blue light. Furthermore, we examined the interaction between PeCRY1 and AtCOP1 using a bimolecular fluorescence complementation (BiFc assay. Our data provide evidence for the involvement of PeCRY1 in the control of photomorphogenesis in poplar.

[Spatiotemporal variation of Populus euphratica's radial increment at lower reaches of Tarim River after ecological water transfer].

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An, Hong-Yan; Xu, Hai-Liang; Ye, Mao; Yu, Pu-Ji; Gong, Jun-Jun

2011-01-01

Taking the Populus euphratica at lower reaches of Tarim River as test object, and by the methods of tree dendrohydrology, this paper studied the spatiotemporal variation of P. euphratic' s branch radial increment after ecological water transfer. There was a significant difference in the mean radial increment before and after ecological water transfer. The radial increment after the eco-water transfer was increased by 125%, compared with that before the water transfer. During the period of ecological water transfer, the radial increment was increased with increasing water transfer quantity, and there was a positive correlation between the annual radial increment and the total water transfer quantity (R2 = 0.394), suggesting that the radial increment of P. euphratica could be taken as the performance indicator of ecological water transfer. After the ecological water transfer, the radial increment changed greatly with the distance to the River, i.e. , decreased significantly along with the increasing distance to the River (P = 0.007). The P. euphratic' s branch radial increment also differed with stream segment (P = 0.017 ), i.e. , the closer to the head-water point (Daxihaizi Reservoir), the greater the branch radial increment. It was considered that the limited effect of the current ecological water transfer could scarcely change the continually deteriorating situation of the lower reaches of Tarim River.

[Hydraulic limitation on photosynthetic rate of old Populus simonii trees in sandy soil of north Shaanxi Province].

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Zuo, Li-Xiang; Li, Yang-Yang; Chen, Jia-Cun

2014-06-01

'Old and dwarf trees' on the loess plateau region mainly occurred among mature trees rather than among small trees. To elucidate the mechanism of tree age on 'old and dwarf trees' formation, taking Populus simonii, a tree species that accounted for the largest portion of 'old and dwarf trees' on the loess plateau, as an example, the growth, photosynthesis and hydraulic traits of P. simonii trees with different ages (young: 13-15 years, mid-aged: 31-34 years, and old: 49-54 years) were measured. The results showed that the dieback length increased, and net photosynthetic rate, stomatal conductance, transpiration rate, and whole plant hydraulic conductance decreased significantly with the increasing tree age. Both net photosynthetic rate and stomatal conductance measured at different dates were significantly and positively related to the whole plant hydraulic conductance, suggesting that the decreasing photosynthetic rate of old trees was possibly caused by the declined hydraulic conductance. Although the resistance to cavitation in stems and leaves was stronger in old trees than in young and mid-aged trees, there were no differences in midday native stem embolization degree and leaf hydraulic conductance based on the vulnerability curve estimation, suggesting that the increased hydraulic resistance of the soil-root system is probably the most important reason for decreasing the whole plant hydraulic conductance of old trees.

Nutrient concentrations in coarse and fine woody debris of Populus tremuloides Michx.-dominated forests, northern Minnesota, USA

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Klockow, Paul A.; D'Amato, Anthony W.; Bradford, John B.; Fraver, Shawn

2014-01-01

Contemporary forest harvesting practices, specifically harvesting woody biomass as a source of bioenergy feedstock, may remove more woody debris from a site than conventional harvesting. Woody debris, particularly smaller diameter woody debris, plays a key role in maintaining ecosystem nutrient stores following disturbance. Understanding nutrient concentrations within woody debris is necessary for assessing the long-term nutrient balance consequences of altered woody debris retention, particularly in forests slated for use as bioenergy feedstocks. Nutrient concentrations in downed woody debris of various sizes, decay classes, and species were characterized within one such forest type, Populus tremuloides Michx.-dominated forests of northern Minnesota, USA. Nutrient concentrations differed significantly between size and decay classes and generally increased as decay progressed. Fine woody debris (≤ 7.5 cm diameter) had higher nutrient concentrations than coarse woody debris (> 7.5 cm diameter) for all nutrients examined except Na and Mn, and nutrient concentrations varied among species. Concentrations of N, Mn, Al, Fe, and Zn in coarse woody debris increased between one and three orders of magnitude, while K decreased by an order of magnitude with progressing decay. The variations in nutrient concentrations observed here underscore the complexity of woody debris nutrient stores in forested ecosystems and suggest that retaining fine woody debris at harvest may provide a potentially important source of nutrients following intensive removals of bioenergy feedstocks.

Energy sensitivity and variability analysis of Populus hybrid short-rotation plantations in northeastern United States. Final report

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Bowersox, T.W.; Blankenhorn, P.R.

1979-10-24

Production of biomass by corn-like plantations has been demonstrated by a number of researchers. These forest analogs of agronomic cropping systems have the potential to yield substantially more biomass per unit area than traditional forests. Care is needed in choosing the appropriate sites, species, spacing, and harvesting strategies. Opportunities for increased yields have been suggested for fertilization and irrigation. Utilization of the biomass from these dense plantations for energy was the focus of this study. Although the amount of energy potential of the biomass is important, the energy output must be greater than the energy input for biomass to have a positive benefit to society. Further, in order to completely evaluate the net energy of the system it is necessary to examine the energy out-to-in ratios on the basis of usable energy (for example, usable heat, process steam and electricity), as well as all of the energies expended in producing, harvesting, transporting and processing the biomass. The objective of this study is to establish and analyze the energy inputs for selected management strategies in order to evaluate the sensitivity and variability of the energy inputs in the net energy analysis, and based on the net energy analysis to recommend a management strategy that minimizes energy inputs while maximizing biomass yield for short-rotation systems of Populus spp. in the northeastern United States.

Gas exchange, dry weights, and chlorophyll contents of Populus tremuloides seedlings grown from gamma-irradiated seeds

International Nuclear Information System (INIS)

Salmonson, B.J.; Zavitkovski, J.

1977-01-01

Photosynthesis and respiration rates of Populus tremuloides seedlings grown from seeds acutely irradiated with gamma rays (at levels of 0, 0.47, 0.94, 1.8, 3.7, 7.5, and 15 kr) were measured using a closed system and infrared (IR) gas analyzer. Dry weights of seedling roots and shoots and chlorophyll contents were also determined. In general, gamma irradiation of seed had little effect on subsequent gas-exchange processes in the plant. Net photosynthesis and dark respiration rates of the seedling at any radiation level were not significantly different from those of the control group. Pooled net photosynthesis of all irradiated seedlings was nonsignificantly lower than that of the control seedlings. The data suggested a slight stimulation in dry-matter production of shoots by low levels of gamma radiation. At the highest levels of radiation, shoot dry weight was significantly reduced. Root production displayed a pattern similar to that of shoots. No trends different from controls were evident in the shoot/root ratios. Total chlorophyll concentrations of the seedling increased over the controls by radiation treatment. Age and radiation effects were evident in the chlorophyll a/b ratios. The chlorophyll a/b ratios decreased with age in both the control and treatment groups. Although in seedlings 39 through 46 days old chlorophyll a/b ratios were higher in the control, chlorophyll a/b ratios were significantly higher in the treatment seedlings at 68 days. Changes in chlorophyll a were primarily responsible for this change

Polyphenols of Salix aegyptiaca modulate the activities of drug metabolizing and antioxidant enzymes, and level of lipid peroxidation.

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Nauman, Mohd; Kale, R K; Singh, Rana P

2018-03-07

Salix aegyptiaca is known for its medicinal properties mainly due to the presence of salicylate compounds. However, it also contains other beneficial phytochemicals such as gallic acid, quercetin, rutin and vanillin. The aim of the study was to examine the redox potential, antioxidant and anti-inflammatory activity of these phytochemicals along with acetylsalicylic acid. The redox potential and antioxidant activity of gallic acid, quercetin, rutin, vanillin and acetylsalicylic acid were determined by oxidation-reduction potential electrode method and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, respectively. In ex vivo studies, antioxidant activity of these phytochemicals was determined by lipid peroxidation and carbonyl content assay in the liver of mice. Anti-inflammatory activity was determined by protein denaturation method. Six-week old C57BL/6 mice treated with gallic acid (100 mg/kg body weight) and acetylsalicylic acid (25 and 50 mg/kg body weight) to investigate their in vivo modulatory effects on the specific activities of drug metabolizing phase I and phase II enzymes, antioxidant enzymes and level of lipid peroxidation in liver. The order of ability to donate electron and antioxidant activity was found to be: gallic acid > quercetin > rutin > vanillin > acetylsalicylic acid. In ex vivo studies, the similar pattern and magnitude of inhibitory effects of these phytochemicals against peroxidative damage in microsomes and protein carbonyl in cytosolic fraction were observed. In in vivo studies, gallic acid and acetylsalicylic acid alone or in combination, enhanced the specific activities of drug metabolizing phase I and phase II enzymes as well as antioxidant enzymes and also inhibited lipid peroxidation in liver. These findings show a close link between the electron donation and antioxidation potential of these phytochemicals, and in turn their biological activity. Gallic acid, quercetin, rutin and vanillin were found to be better electron donors and

Silviculture and biology of short-rotation woody crops in temperate regions: Then and now

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Dickmann, Donald I. [Department of Forestry, Michigan State University, East Lansing, MI 48824-1222 (United States)

2006-08-15

Although its roots are in antiquity, the current concept of short-rotation woody crops (SRWC) for fiber and energy evolved scientifically from pioneering tree breeding work begun in the early 20th century. A natural outgrowth of this work was the culture of fast-growing trees on rotations of 1-15 years. Close-spaced tree culture received further impetus with the introduction of the 'silage sycamore' concept in the southeastern US in the mid-1960s and the OPEC oil embargo in 1973, leading to statistically designed trials at numerous locations in North America, Europe, and Scandinavia. Early silvicultural research focused on spacing and species trials, propagation methods, site preparation, weed management, nutrition, growth, and yield. Because these trials were based on small plots, and the importance of pest depredations or site variation were not fully recognized, early biomass yield predictions tended to be overly optimistic. Soon physiologists and ecologists began to unravel the biological characteristics of SRWC plantations and their responses to environment. Knowledge of the influence and diversity of pests-insects, diseases, and animals-provided a necessary reality check. Many hardwood tree species and a few conifers have been evaluated over the years for SRWC in temperate regions of the world. Clones of Populus and Salix, however, became the dominant plantation material because of their inherently rapid growth and ease of propagation by hardwood cuttings. Among conifers, loblolly pine (Pinus taeda) also shows promise. Because genetic variation is readily exploitable in the dominant SRWC taxa, strongly focused breeding programs began to provide highly productive genotypes and seed sources in the last decades of the 20th century. A new plateau, with significant practical potential, was reached in the late 20th century when biotechnological methods were applied to tree taxa. Recently, the DNA in the Populus genome was sequenced. Thus, the few current

Remediation of cyanide-contaminated industrial sites through woody biomass production

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Dimitrova, Tsvetelina; Repmann, Frank; Freese, Dirk

2017-04-01

Due to the unfavourable chemical and physical soil quality parameters and the potential presence of contaminants, former industrial sites can hardly be utilized as arable land and can thus be classified as marginal areas. Still, as far as possible, they can effectively be used for the production of alternative energy, including the cultivation of fast growing trees. Apart from being a source of bioenergy, trees might facilitate the stabilization, remedation, contaminant extraction and degradation and, not on the last place, to enhance soil quality improvement on former industrial areas. This process is known as phytoremediation and has successfully been applied on industrial sites of various organic and inorganic contamination. The former manufactured gas plant site ( 2500 m2) "ehemalige Leuchtgasanstalt" Cottbus, contaminated, among others, with iron cyanides undergoes phytoremediation with simultaneous biomass production since 2011. The project "Biomass-Remediation" is fully financed by the German Railways JSC. A dense (23700 stems/ha), mixed cover of willow (Salix caprea), poplar (Populus maximowicii Henry x Populus trichocarpa Torr. et Gray (Hybrid 275)) and black locust (Robinia pseudoaccacia) trees has been planted on the site. Throughout the five years of remediation, a successful long-term stabilization of the site has been achieved as a result of the nearly outright established tree stock and the dense planting. Annual monitoring of the cyanide levels in the leaf tissue of the trees on the site and results from greenhouse experiments indicate the ability of all tree species to extract and transport the cyanide from the soil. Additonally, the greenhouse experiments suggest that the willows might be able, although not to a full extent, to detoxify the contaminant by splitting the CN moiety. The contaminated biomass material might easily be dealt with through regular harvests and subsequent incineration. Phytoremediation with simultaneous biomass production

Determination of Fe, Hg, Mn, and Pb in three-rings of poplar (Populus alba L.) by U-shaped DC arc

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Marković, D. M.; Novović, I.; Vilotić, D.; Ignjatović, Lj.

2007-09-01

The U-shaped DC arc with aerosol supply was applied for the determination of Fe, Hg, Mn, and Pb in poplar (Populus alba L.) tree-rings. By optimization of the operating parameters and by selection of the most appropriate signal integration time (20 s for Fe, Mn, and Pb and 30 s for Hg), the obtained limits of detection for Fe, Hg, Mn, and Pb are 5.8, 2.6, 1.6, and 2.0 ng/ml, respectively. The detection limits achieved by this method for Fe, Hg, Mn, and Pb are comparable with the detection limits obtained for these elements by such methods as inductively coupled plasma-atomic emission spectrometry (ICP-AES), direct coupled plasmatomic emission spectrometry (DCP-AES), and microwave-induced plasma-atomic emission spectrometry (MIP-AES). We used the tree-rings of poplar from two different locations. The first one is in the area close to the power plant “Nikola Tesla” TENT A, Obrenovac, while the other one is in the urban area of Novi Sad. In almost all cases, samples from the location at Obrenovac registered elevated average concentrations of Fe, Hg, Mn, and Pb in the tree-rings of poplar.

Dicty_cDB: Contig-U13006-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available A-FP_182294 Lysiphlebus testaceipes adult whol... 34 3.0 2 ( BU896130 ) X036A07 Populus wood cDNA library Populus tremul...1.r GM_WBc Glycine max genomic clone ... 34 2.9 2 ( DN492755 ) X036A07.3pR Populus wood cDNA library Populus tre...... 34 2.9 2 ( DN502768 ) X036A07.5pR Populus wood cDNA library Populus tre... 34 2.9 2 ( EH014215 ) USD..... 34 2.4 2 ( EU795178 ) Uncultured bacterium HF0010_09O16 genomic sequence. 34 2.4 2 ( AC182691 ) Populus tric...itermes flavipes symbiont library ... 36 3.2 2 ( DQ927304 ) Tetrahymena paravorax strain RP m

Does SO{sub 2} fumigation change the chemical defense of woody plants: the effect of short-term SO{sub 2} fumigation on the metabolism of deciduous Salix Myrsinifolia plants

Energy Technology Data Exchange (ETDEWEB)

Julkunen-Tiitto, R.; Lavola, A.; Kainulainen, P. [University of Joensuu, Joensuu (Finland). Dept. of Biology

1995-08-01

The effect of a moderate increase in atmospheric sulfur dioxide on the production of phenolic secondary chemicals, soluble sugars and phytomass distribution within plants was investigated in six willow ({ital Salix myrsinifolia Salisb}) clones. The plants were cultivated for 3 weeks under 0.11 ppm of SO{sub 2} (300{mu}g m{sup -3}). The production of salicin and chlorogenic acid was significantly reduced under increased SO{sub 2}. However, salicortin, 2{prime}-O-acetylsalicortin, (+)-catechin and two unknown phenolics did not show any clear trend. The increase in SO{sub 2} did not affect the glucose, fructose and sucrose contents. The final weight of the SO{sub 2}-treatment plants was significantly greater than that of the control plants: the leaf, stem and root phytomass was from 14 to 48% greater under increased SO{sub 2}. All the clones showed the same trend, although there was a significant variation in phytomass production. Results indicate, although not consistently, that even a short-term exposure of enhanced atmospheric SO{sub 2} may change moderately the accumulation pattern of willow phenolics. 20 refs., 2 tabs.

Identification of five B-type response regulators as members of a multistep phosphorelay system interacting with histidine-containing phosphotransfer partners of Populus osmosensor

Directory of Open Access Journals (Sweden)

Bertheau Lucie

2012-12-01

Full Text Available Abstract Background In plants, the multistep phosphorelay signaling pathway mediates responses to environmental factors and plant hormones. This system is composed of three successive partners: hybrid Histidine-aspartate Kinases (HKs, Histidine-containing Phosphotransfer proteins (HPts, and Response Regulators (RRs. Among the third partners, B-type RR family members are the final output elements of the pathway; they act as transcription factors and clearly play a pivotal role in the early response to cytokinin in Arabidopsis. While interactions studies between partners belonging to the multistep phosphorelay system are mainly focused on protagonists involved in cytokinin or ethylene pathways, very few reports are available concerning partners of osmotic stress signaling pathway. Results In Populus, we identified eight B-type RR proteins, RR12-16, 19, 21 and 22 in the Dorskamp genotype. To assess HPt/B-type RR interactions and consequently determine potential third partners in the osmosensing multistep phosphorelay system, we performed global yeast two-hybrid (Y2H assays in combination with Bimolecular Fluorescence Complementation (BiFC assays in plant cells. We found that all B-type RRs are able to interact with HPt predominant partners (HPt2, 7 and 9 of HK1, which is putatively involved in the osmosensing pathway. However, different profiles of interaction are observed depending on the studied HPt. HPt/RR interactions displayed a nuclear localization, while the nuclear and cytosolic localization of HPt and nuclear localization of RR proteins were validated. Although the nuclear localization of HPt/RR interaction was expected, this work constitutes the first evidence of such an interaction in plants. Furthermore, the pertinence of this partnership is reinforced by highlighting a co-expression of B-type RR transcripts and the other partners (HK1 and HPts belonging to a potential osmosensing pathway. Conclusion Based on the interaction studies

The impact of vessel size on vulnerability curves: data and models for within-species variability in saplings of aspen, Populus tremuloides Michx.

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Cai, Jing; Tyree, Melvin T

2010-07-01

The objective of this study was to quantify the relationship between vulnerability to cavitation and vessel diameter within a species. We measured vulnerability curves (VCs: percentage loss hydraulic conductivity versus tension) in aspen stems and measured vessel-size distributions. Measurements were done on seed-grown, 4-month-old aspen (Populus tremuloides Michx) grown in a greenhouse. VCs of stem segments were measured using a centrifuge technique and by a staining technique that allowed a VC to be constructed based on vessel diameter size-classes (D). Vessel-based VCs were also fitted to Weibull cumulative distribution functions (CDF), which provided best-fit values of Weibull CDF constants (c and b) and P(50) = the tension causing 50% loss of hydraulic conductivity. We show that P(50) = 6.166D(-0.3134) (R(2) = 0.995) and that b and 1/c are both linear functions of D with R(2) > 0.95. The results are discussed in terms of models of VCs based on vessel D size-classes and in terms of concepts such as the 'pit area hypothesis' and vessel pathway redundancy.

Methylobacterium populi sp. nov., a novel aerobic, pink-pigmented, facultatively methylotrophic, methane-utilizing bacterium isolated from poplar trees (Populus deltoides x nigra DN34).

Science.gov (United States)

Van Aken, Benoit; Peres, Caroline M; Doty, Sharon Lafferty; Yoon, Jong Moon; Schnoor, Jerald L

2004-07-01

A pink-pigmented, aerobic, facultatively methylotrophic bacterium, strain BJ001T, was isolated from internal poplar tissues (Populus deltoidesxnigra DN34) and identified as a member of the genus Methylobacterium. Phylogenetic analyses showed that strain BJ001T is related to Methylobacterium thiocyanatum, Methylobacterium extorquens, Methylobacterium zatmanii and Methylobacterium rhodesianum. However, strain BJ001T differed from these species in its carbon-source utilization pattern, particularly its use of methane as the sole source of carbon and energy, an ability that is shared with only one other member of the genus, Methylobacterium organophilum. In addition, strain BJ001T is the only member of the genus Methylobacterium to be described as an endophyte of poplar trees. On the basis of its physiological, genotypic and ecological properties, the isolate is proposed as a member of a novel species of the genus Methylobacterium, Methylobacterium populi sp. nov. (type strain, BJ001T=ATCC BAA-705T=NCIMB 13946T).

Rooting of hybrid clones of Populus tremula L. x P. tremuloides Michx. by stem cuttings derived from micropropagated plants

Energy Technology Data Exchange (ETDEWEB)

Qibin Yu [Univ. of Helsinki (Finland). Dept. of Plant Biology; Maentylae, N. [Univ. of Turku (Finland). Dept. of Biology, Plant Physiology and Molecular Biology; Salonen, M. [Finnish Forest Research Inst., Laeyliaeinen (Finland). Haapastensyrjae Breeding Station

2001-07-01

Propagation costs could be cut by replacing part of the micropropagation process with steps involving more traditional techniques. This study explored possibilities for improving existing vegetative propagation techniques for aspen using stem cuttings obtained from micropropagated plants. Vegetative propagation through stem cuttings was studied in 10 micropropagated hybrid aspen clones (Populus tremula L. x P. tremuloides Michx). Cuttings containing one axillary bud were harvested from the same donor plants twice during the growing season: the first harvest in May and the second harvest in July. Rooting percentage was correlated positively with root length, number of roots and height of cutting plant but negatively with length of rooting. The average rooting percentage was 53% in the first harvest and 27% in second harvest. Indole-3-butyric acid treatments (1.2 mM) significantly improved rooting in the second harvest, but not in the first harvest, suggesting different endogenous auxin levels in the cuttings. A significant variation for most traits related to rooting ability was found among the clones, indicating that clonal effects play an important role in the propagation of aspen. Thus, clones with a good response in shoot growth and rooting could be exploited in large-scale propagation using stem cuttings.

Salix fication

African Journals Online (AJOL)

SAM

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Alfa analysis of genetic diversity in populus cathayana rehd originating from south eastern Qinghai-Tibetan plateau of China

International Nuclear Information System (INIS)

Chen, K.; Peng, Y.

2010-01-01

The wide geographical and climatic distribution of Populus cathayana Rehd indicates that there is a large amount of genetic diversity available, which can be exploited for conservation, breeding programs and afforestation schemes. In our study, genetic diversity was evaluated in the natural populations of P. cathayana originating from southern and eastern areas of the Qinghai-Tibetan Plateau of China by means of AFLP markers. For four primer combinations, a total of 175 bands were obtained of which 173 (98.9%) were polymorphic. Six natural populations of P. cathayana possessed different levels of genetic diversity, high level of genetic differentiation existed among the populations (G/sub st) =0.489) of P. cathayana. Individuals cluster and PCO analysis based on Jaccards's similarity coefficient also showed evident population genetic structure with high level of population genetic differentiation. The long evolutionary process coupled with genetic drift within populations, rather than contemporary gene flow, are the major forces shaping genetic structure of P. cathayana populations. Moreover, there was no correspondence between geographical and genetic distances in the populations of P. cathayana, seldom gene exchange among the populations and different selection pressures may be the causes. Our findings of different levels of genetic diversity within populations and high level of genetic differentiation among the populations provided promising condition for further breeding and conservation programs. (author)

Identification of proteins from cambium tissues of the chinese white poplar (populus tomentosa) sampled during the growing season

International Nuclear Information System (INIS)

Xie, J.; Liu, S.; Qi, Q.; Hou, Y.

2014-01-01

Various protein extraction methods have been used to investigate Chinese white poplar (Populus tomentosa) proteomics. However, extracting and characterizing proteins from woody plants remains a challenge. Two-dimensional gel electrophoresis is a powerful, widely used method for the analysis of complex protein mixtures extracted from biological samples. The technique separates mixtures of proteins along two dimensions, by isoelectric point and molecular weight, and can resolve thousands of different proteins. Here, we report a new application of two-dimensional gel electrophoresis to investigate the proteomics of P. tomentosa cambium tissues over the course of a growing season. Of three protein extraction methods that we compared (the Tris-phenol method, trichloroacetic acid-acetone method, and trichloroacetic acid-acetone-phenol method), trichloroacetic acid-acetone was the most efficient approach for protein extraction from cambium tissues of P. tomentosa. After extraction, the proteins were separated using two-dimensional gel electrophoresis. The protein quantities of six spots changed over the course of the growing season from February to July. Five spots were identified using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry, and the sixth spot was identified by liquid chromatography-mass spectrometry. The proteins included enolase, class Ia chitinase, and four unnamed proteins. Our results show the best approach to proteomics in P. tomentosa and reveal trends in protein activities during a growing season in this tree species. (author)

Growth, leaf traits and litter decomposition of roadside hybrid aspen (Populus tremula L. x P. tremuloides Michx.) clones

International Nuclear Information System (INIS)

Nikula, Suvi; Manninen, Sirkku; Vapaavuori, Elina; Pulkkinen, Pertti

2011-01-01

Road traffic contributes considerably to ground-level air pollution and is therefore likely to affect roadside ecosystems. Differences in growth and leaf traits among 13 hybrid aspen (Populus tremula x P. tremuloides) clones were studied in relation to distance from a motorway. The trees sampled were growing 15 and 30 m from a motorway and at a background rural site in southern Finland. Litter decomposition was also measured at both the roadside and rural sites. Height and diameter growth rate and specific leaf area were lowest, and epicuticular wax amount highest in trees growing 15 m from the motorway. Although no significant distance x clone interactions were detected, clone-based analyses indicated differences in genotypic responses to motorway proximity. Leaf N concentration did not differ with distance from the motorway for any of the clones. Leaf litter decomposition was only temporarily retarded in the roadside environment, suggesting minor effects on nutrient cycling. - Highlights: → Roadside hybrid aspen displayed xeromorphic leaf traits and reduction in growth rate. → These responses were limited to trees close to the motorway and only to some clones. → Leaf litter decomposition was only temporarily retarded in the roadside environment. - Hybrid aspen had more xeromorphic leaves, displayed reduced growth, and showed retarded litter decomposition at an early stage in the roadside environment.

Cloning and characterization of an AUX/IAA gene in Populus davidiana x P. alba var. Pyramidalis and the correlation between its time-course expression and the levels of indole-3-acetic in saplings inoculated with Trichoderma

International Nuclear Information System (INIS)

Yao, Z.; Baloch, A.M.; Zhai, T.; Jiang, C.; Liu, Z.; Zhang, R.

2018-01-01

Poda AUX/IAA gene, encoding an early-stage responsive protein to auxin in Populus davidiana x P. alba var. pyramidalis (Shanxin poplar), was cloned. The length of mRNA transcript of Poda AUX/IAA was 741bp, encoding a 248-amino-acid protein product, Poda AUX/IAA ORF analysis suggested that Poda AUX/IAA contained one conserved domain (pfam02309). Predicted molecular weight of Poda AUX/IAA was found to be 27kDa and its theoretical isoelectric point was determined as 8.21. Poda AUX/IAA was predicted to be a hydrophilic nucleoprotein and its multi-sequence alignment analysis showed that it shares high identity in four conserved domains with eight AUX/IAA proteins in other Populus species and these sequences of Poda AUX/IAA shared highest similarity with Pt-IAA14.1 in P. trichocarpa. In this study, we found that Poda AUX/IAA was expressed in both leaves and roots of Shanxin poplar. Three strains of Trichoderma asperellum were used to inoculate Shanxin poplar saplings. Inoculated saplings were cultured for 72 h. It was then found that IAA levels in both leaves and roots of inoculated saplings gradually increased and time-course expression patterns of PodaAUX/IAA was changed along with IAA levels. Results of Pearson correlation analysis demonstrated a negative correlation between expression levels of Poda AUX/IAA and IAA levels in both leaves and roots of Shanxin poplar saplings when compared with control. Negative correlation in inoculated saplings were less significant, probably as a result of Trichoderma inducing. (author)

Genetic variation of the riparian pioneer tree species populus nigra. II. Variation In susceptibility to the foliar rust melampsora larici-populina

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Legionnet; Muranty; Lefevre

1999-04-01

Partial resistance of Populus nigra L. to three races of the foliar rust Melampsora larici-populina Kleb. was studied in a field trial and in laboratory tests, using a collection of P. nigra originating from different places throughout France. No total resistance was found. The partial resistance was split into epidemiological components, which proved to be under genetic control. Various patterns of association of epidemiological components values were found. Principal components analysis revealed their relationships. Only 24% of the variance of the field susceptibility could be explained by the variation of the epidemiological components of susceptibility. This variable was significantly correlated with susceptibility to the most ancient and widespread race of the pathogen, and with the variables related to the size of the lesions of the different races. Analysis of variance showed significant differences in susceptibility between regions and between stands within one region. Up to 20% of variation was between regions, and up to 22% between stands, so that these genetic factors appeared to be more differentiated than the neutral diversity (up to 3.5% Legionnet & Lefevre, 1996). However, no clear pattern of geographical distribution of diversity was detected.

Can the capacity for isoprene emission acclimate to environmental modifications during autumn senescence in temperate deciduous tree species Populus tremula?

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Sun, Zhihong; Copolovici, Lucian; Niinemets, Ülo

2012-03-01

Changes in isoprene emission (Φ(isoprene)), and foliage photosynthetic (A) rates, isoprene precursor dimethylallyldiphosphate (DMADP), and nitrogen and carbon contents were studied from late summer to intensive leaf fall in Populus tremula to gain insight into the emission controls by temperature and endogenous, senescence-induced, modifications. Methanol emissions, characterizing degradation of cell wall pectins, were also measured. A rapid reduction in Φ(isoprene) and A of 60-70% of the initial value was observed in response to a rapid reduction of ambient temperature by ca. 15°C (cold stress). Later phases of senescence were associated with further reductions in Φ(isoprene) and A, with simultaneous major decrease in nitrogen content. However, during episodes of temperature increase, A and in particular, Φ(isoprene) partly recovered. Variation in Φ(isoprene) during senescence was correlated with average temperature of preceding days, with the highest degree of explained variance observed with average temperature of 6 days. Throughout the study, methanol emissions were small, but a large burst of methanol emission was associated with leaf yellowing and abscission. Overall, these data demonstrate that the capacity for isoprene emission can adjust to environmental conditions in senescing leaves as well, but the responsiveness is low compared with mid-season and is also affected by stress.

Environmental Biotechnology Screening Cu and Cd tolerance in ...

African Journals Online (AJOL)

GRACE

2006-07-03

Jul 3, 2006 ... Hydroponic culture has been used to compare copper and cadmium tolerance in five Salix species from ... The use of some Salix species in phytoremediation for the removal of heavy metals from contaminated soils,.

Late Quaternary palaeoecological and palaeoclimatological reconstruction in the Gutaiului Mountains, northwest Romania

Science.gov (United States)

Feurdean, Angelica; Bennike, Ole

2004-12-01

Macrofossil, pollen, lithostratigraphy, mineral magnetic measurements (SIRM and magnetic susceptibility), loss-on-ignition, and AMS radiocarbon dating on sediments from two former crater lakes, situated at moderate altitudes in the Gutaiului Mountains of northwest Romania, allow reconstruction of Late Quaternary climate and environment. Shrubs and herbs with steppe and montane affinities along with stands of Betula and Pinus, colonised the surroundings of the sites prior to 14 700 cal. yr BP and the inferred climatic conditions were cold and dry. The gradual transition to open Pinus-Betula forests, slightly higher lake water temperatures, and higher lake productivity, indicate more stable environmental conditions between 14 700 and 14 100 cal. yr BP. This development was interrupted by cooler and drier climatic conditions between 14 100 and 13 800 cal. yr BP, as inferred from a reduction of open forests to patches, or stands, of Pinus, Betula, Larix, Salix and Populus. The expansion of a denser boreal forest, dominated by Picea, but including Pinus, Larix, Betula, Salix, and Ulmus started at 13 800 cal. yr BP, although the forest density seems to have been reduced between 13400 and 13200cal.yrBP. Air temperature and moisture availability gradually increased, but a change towards drier conditions is seen at 13400cal.yrBP. A distinct decrease in temperature and humidity between 12900 and 11500cal.yrBP led to a return of open vegetation, with patches of Betula, Larix, Salix, Pinus and Alnus and individuals of Picea. Macrofossils and pollen of aquatic plants indicate rising lake water temperatures and increased aquatic productivity already by ca. 11800cal.yrBP, 300 years earlier than documented by the terrestrial plant communities. At the onset of the Holocene, 11500cal.yrBP, forests dominated by Betula, Pinus and Larix expanded and were followed by dense Ulmus forests with Picea, Betula and Pinus at 11250cal.yrBP. Larix pollen was not found, but macrofossil evidence

Allometric equations commonly used for estimating shoot biomass in short-rotation wood energy species: a review

Directory of Open Access Journals (Sweden)

Julio Cesar Ríos-Saucedo

2016-01-01

Full Text Available Los cultivos dendroenergéticos de corta rotación en monte bajo (Short Rotation Coppice -SRC comúnmente están formados por individuos unifustales en el primer ciclo de corta, pero a partir del segundo ciclo, de cada cepa surgen numerosos vástagos o brotes, los cuales presentan desafíos interesantes al momento de estimar su biomasa. El objetivo de este trabajo fue identificar especies, longitud de rotación y tipos de modelos alométricos usados para estimar biomasa en SRC, en revistas científicas de las bases de datos Scopus y Web of Science. Entre los modelos para estimar la biomasa (y de uso más frecuente destaca el exponencial, que tiene como variable predictora el diámetro normal ( D ( y = b 0 D b 1 , diámetro basal de tallo ( Db ( y = b 0 Db b 1 y la combinación de diámetro normal al cuadrado por la altura total ( D 2 H ( y = b 0 + b 1 D 2 H . Los géneros con mayor número de modelos diferentes fueron Populus, Salix y Eucalyptus . Los dos primeros son los más estudiados. La longitud de rotación empleada en los cultivos estudiados varió de uno a 15 años.

Ozone air pollution and foliar injury development on native plants of Switzerland

International Nuclear Information System (INIS)

Novak, Kristopher; Skelly, John M.; Schaub, Marcus; Kraeuchi, Norbert; Hug, Christian; Landolt, Werner; Bleuler, Peter

2003-01-01

Visible ozone-induced foliar injury on native forest species of Switzerland was identified and confirmed under ambient OTC-conditions and related to the current European AOT40 standard. - The objectives of this study were to examine the foliar sensitivity to ozone exposure of 12 tree, shrub, and herbaceous species native to southern Switzerland and determine the seasonal cumulative ozone exposures required to induce visible foliar injury. The study was conducted from the beginning of May through the end of August during 2000 and 2001 using an open-top chamber research facility located within the Lattecaldo Cantonal Forest Nursery in Canton Ticino, southern Switzerland (600 m asl). Plants were examined daily and dates of initial foliar injury were recorded in order to determine the cumulative AOT40 ppb h ozone exposure required to cause visible foliar injury. Plant responses to ozone varied significantly among species; 11 species exhibited visible symptoms typical of exposures to ambient ozone. The symptomatic species (from most to least sensitive) were Populus nigra, Viburnum lantana, Salix alba, Crataegus monogyna, Viburnum opulus, Tilia platyphyllos, Cornus alba, Prunus avium, Fraxinus excelsior, Ribes alpinum, and Tilia cordata; Clematis spp. did not show foliar symptoms. Of the 11 symptomatic species, five showed initial injury below the critical level AOT40 10 ppmh O 3 in the 2001 season

Impacts of Vegetation Growth on Reach-scale Flood Hydraulics in a Sand-bed River and the Implications for Vegetation-morphology Coevolution

Science.gov (United States)

Box, S.; Wilcox, A. C.

2017-12-01

Vegetation alters flood hydraulics and geomorphic response, yet quantifying and predicting such responses across spatial and temporal scales remains challenging. Plant- and patch-scale studies consistently show that vegetation increases local hydraulic variability, yet reach-scale hydrodynamic models often assume vegetation has a spatially homogeneous effect on hydraulics. Using Nays2DH in iRIC (International River Interface Cooperative), we model the effect of spatially heterogeneous vegetation on a series of floods with varying antecedent vegetation conditions in a sand-bed river in western Arizona, taking advantage of over a decade of data on a system that experienced substantial geomorphic, hydrologic, and ecosystem changes. We show that pioneer woody seedlings (Tamarix, Populus, Salix) and cattail (Typha) increase local hydraulic variability, including velocity and bed shear stress, along individual cross sections, predominantly by decreasing velocity in zones of vegetation establishment and growth and increasing velocity in unvegetated areas, with analogous effects on shear stress. This was especially prominent in a study reach where vegetation growth contributed to thalweg incision relative to a vegetated bar. Evaluation of these results in the context of observed geomorphic response to floods elucidates mechanisms by which vegetation and channel morphology coevolve at a reach scale. By quantifying the influence of spatially heterogeneous vegetation on reach-scale hydraulics, we demonstrate that plant- and patch-scale research on vegetation hydraulics is applicable to ecogeomorphology at the reach scale.