WorldWideScience

Sample records for planted hardwood seedlings

  1. Planting and care of fine hardwood seedlings: Planting hardwood seedlings in the Central Hardwood Region.

    Science.gov (United States)

    Paula M. Pijut

    2003-01-01

    Forest tree planting in the United States on public and private land exceeded 2.6 million acres in 1999. Of that total, approximately 1.3 million acres (48 percent) were planted by private individuals (AF & PA 2001). In the Central Hardwood Region forest tree planting by private landowners exceeded 100,000 acres in 1999. Trees are planted for various reasons...

  2. Planting and care of fine hardwood seedlings: Nursery production of hardwood seedlings

    Science.gov (United States)

    Douglass F. Jacobs

    2003-01-01

    Access to quality tree seedlings is an essential component of a successful hardwood reforestation project. Hardwood plantations may be established by sowing seed directly to a field site, but the success of direct seeding operations has been inconsistent for many species, which indicates that more research is needed before this practice can be recommended. For...

  3. Planting and care of fine hardwood seedlings: diseases in hardwood tree plantings

    Science.gov (United States)

    Paula M. Pijut

    2006-01-01

    Hardwood trees planted for timber production, wildlife habitat, riparian buffers, native woodland restoration, windbreaks, watershed protection, erosion control, and conservation are susceptible to damage or even death by various native and exotic fungal or bacterial diseases. Establishment, growth, and the quality of the trees produced can be affected by these disease...

  4. Planting and care of fine hardwood seedlings: Diagnosing and controlling wildlife damage in hardwood plantations.

    Science.gov (United States)

    James McKenna; Keith Woeste

    2004-01-01

    Once trees are planted and begin growing, damage from wildlife can threaten their quality. In this publication we discuss how to identify and manage injury to hardwoods from wildlife to minimize losses.

  5. Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area

    International Nuclear Information System (INIS)

    Mayer, J.J.

    1999-01-01

    Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. The depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery of the wild pig damage, these areas were surveyed on foot to assess the magnitude of the depredation on the planted seedling crop. Foraging by the local wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the surveys, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreatment methodology is thought to have been the primary aspect of the restoration program that initially led the wild pigs to discover the planted seedlings. In addition, it is possible that a combination of other factors associated with odor and taste may have resulted in the selective depredation. Future wetland restoration efforts in areas with wild pigs should consider pretreatment methods and species to be planted. If pretreatment methods and species such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species

  6. Selective depredation of planted hardwood seedlings by wild pigs in a wetland restoration area

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, J.J.

    1999-12-17

    Following the planting of several thousand hardwood seedlings in a 69-ha wetland restoration area in west-central South Carolina, wild pigs (Sus scrofa) depredated a large percentage of the young trees. This planting was undertaken as part of a mitigation effort to restore a bottomland hardwood community in the corridor and delta of a third order stream that had been previously impacted by the discharge of heated nuclear reactor effluent. The depredated restoration areas had been pretreated with both herbicide and control burning prior to planting the hardwood seedlings. After discovery of the wild pig damage, these areas were surveyed on foot to assess the magnitude of the depredation on the planted seedling crop. Foraging by the local wild pigs in the pretreatment areas selectively impacted only four of the nine hardwood species used in this restoration effort. Based on the surveys, the remaining five species did not appear to have been impacted at all. A variety of reasons could be used to explain this phenomenon. The pretreatment methodology is thought to have been the primary aspect of the restoration program that initially led the wild pigs to discover the planted seedlings. In addition, it is possible that a combination of other factors associated with odor and taste may have resulted in the selective depredation. Future wetland restoration efforts in areas with wild pigs should consider pretreatment methods and species to be planted. If pretreatment methods and species such as discussed in the present study must be used, then the prior removal of wild pigs from surrounding lands will help prevent depredations by this non-native species.

  7. Planting and care of fine hardwood seedlings: Designing hardwood tree plantings for wildlife

    Science.gov (United States)

    Brian J. MacGowan

    2003-01-01

    Woody plants can be of value to many wildlife species. The species of tree or shrub, or the location, size, and shape of planting can all have an impact on wildlife. The purpose of this paper is to discuss the benefits of trees and shrubs for wildlife and how to design tree and shrub plantings for wildlife. Some of the practices may conflict with other management...

  8. Planting and care of fine hardwood seedlings: Financial and tax aspects of tree planting

    Science.gov (United States)

    William L. Hoover

    2004-01-01

    Trees are planted for many reasons, including soil and water conservation, wildlife habitat, nut and timber production. Altruism motivates many landowners to plant trees. There are, however, those who plant with the expectation of increasing their family's wealth. In this publication I discuss the financial and tax aspects of tree planting projects. The focus is...

  9. Bottomland Hardwood Planting: Example Contract Specifications

    National Research Council Canada - National Science Library

    Humprey, Monica

    2002-01-01

    This technical note provides an example of contract specifications that can be used as a template by USACE biologists, engineers, or contracting officers for contracting the planting of bottomland hardwood (BLH) seedlings...

  10. Quantifying flooding effects on hardwood seedling survival and growth for bottomland restoration

    Science.gov (United States)

    John M. Kabrick; Daniel C. Dey; J.W. Van Sambeek; Mark V. Coggeshall; Douglass F. Jacobs

    2012-01-01

    Growing interest worldwide in bottomland hardwood restoration necessitates improved ecological understanding of flooding effects on forest tree seedlings using methodology that accurately reflects field conditions. We examined hardwood seedling survival and growth in an outdoor laboratory where the timing, depth, duration, and flow rate of flood water can be carefully...

  11. California’s Hardwood Resource: Seeds, Seedlings, and Sprouts of Three Important Forest-Zone Species

    Science.gov (United States)

    Philip M. McDonald; John C. Tappeiner

    2002-01-01

    Although California black oak, tanoak, and Pacific madrone are the principal hardwood species in the forest zone of California and Oregon and are key components of many plant communities, their seed production, regeneration, and early growth requirements have received little study. Information is presented on seed production, storage, and germination, and on the...

  12. A Forest Tent Caterpillar Outbreak Increased Resource Levels and Seedling Growth in a Northern Hardwood Forest.

    Directory of Open Access Journals (Sweden)

    Danaë M A Rozendaal

    Full Text Available In closed-canopy forests, gap formation and closure are thought to be major drivers of forest dynamics. Crown defoliation by insects, however, may also influence understory resource levels and thus forest dynamics. We evaluate the effect of a forest tent caterpillar outbreak on understory light availability, soil nutrient levels and tree seedling height growth in six sites with contrasting levels of canopy defoliation in a hardwood forest in northern lower Michigan. We compared resource levels and seedling growth of six hardwood species before, during and in the three years after the outbreak (2008-2012. Canopy openness increased strongly during the forest tent caterpillar outbreak in the four moderately and severely defoliated sites, but not in lightly defoliated sites. Total inorganic soil nitrogen concentrations increased in response to the outbreak in moderately and severely defoliated sites. The increase in total inorganic soil nitrogen was driven by a strong increase in soil nitrate, and tended to become stronger with increasing site defoliation. Seedling height growth increased for all species in the moderately and severely defoliated sites, but not in lightly defoliated sites, either during the outbreak year or in the year after the outbreak. Growth increases did not become stronger with increasing site defoliation, but were strongest in a moderately defoliated site with high soil nutrient levels. Growth increases tended to be strongest for the shade intolerant species Fraxinus americana and Prunus serotina, and the shade tolerant species Ostrya virginiana. The strong growth response of F. americana and P. serotina suggests that recurring forest tent caterpillar outbreaks may facilitate the persistence of shade intolerant species in the understory in the absence of canopy gaps. Overall, our results suggest that recurrent canopy defoliation resulting from cyclical forest insect outbreaks may be an additional driver of dynamics in

  13. A Forest Tent Caterpillar Outbreak Increased Resource Levels and Seedling Growth in a Northern Hardwood Forest.

    Science.gov (United States)

    Rozendaal, Danaë M A; Kobe, Richard K

    2016-01-01

    In closed-canopy forests, gap formation and closure are thought to be major drivers of forest dynamics. Crown defoliation by insects, however, may also influence understory resource levels and thus forest dynamics. We evaluate the effect of a forest tent caterpillar outbreak on understory light availability, soil nutrient levels and tree seedling height growth in six sites with contrasting levels of canopy defoliation in a hardwood forest in northern lower Michigan. We compared resource levels and seedling growth of six hardwood species before, during and in the three years after the outbreak (2008-2012). Canopy openness increased strongly during the forest tent caterpillar outbreak in the four moderately and severely defoliated sites, but not in lightly defoliated sites. Total inorganic soil nitrogen concentrations increased in response to the outbreak in moderately and severely defoliated sites. The increase in total inorganic soil nitrogen was driven by a strong increase in soil nitrate, and tended to become stronger with increasing site defoliation. Seedling height growth increased for all species in the moderately and severely defoliated sites, but not in lightly defoliated sites, either during the outbreak year or in the year after the outbreak. Growth increases did not become stronger with increasing site defoliation, but were strongest in a moderately defoliated site with high soil nutrient levels. Growth increases tended to be strongest for the shade intolerant species Fraxinus americana and Prunus serotina, and the shade tolerant species Ostrya virginiana. The strong growth response of F. americana and P. serotina suggests that recurring forest tent caterpillar outbreaks may facilitate the persistence of shade intolerant species in the understory in the absence of canopy gaps. Overall, our results suggest that recurrent canopy defoliation resulting from cyclical forest insect outbreaks may be an additional driver of dynamics in temperate closed

  14. Planting and care of fine hardwood seedlings: Regenerating hardwoods in the Central Hardwoods Region: Soils

    Science.gov (United States)

    Felix Ponder, Jr.; Phillip E. Pope

    2003-01-01

    A large number of factors determine the successful establishment of trees. The site for a tree refers to where it grows, and includes living and nonliving factors that may have an impact on the tree's survival and growth. Site factors may be similar enough over a large area so as to be considered one site or different enough to be considered different sites....

  15. Chemical Weed Control Increases Survival and Growth in Hardwood Plantings

    Science.gov (United States)

    Gayne G. Erdmann

    1967-01-01

    In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond...

  16. Invasive plant species in hardwood tree plantations

    Science.gov (United States)

    Rochelle R. Beasley; Paula M. Pijut

    2010-01-01

    Invasive plants are species that can grow and spread aggressively, mature quickly, and invade an ecosystem causing economic and environmental damage. Invasive plants usually invade disturbed areas, but can also colonize small areas quickly, and may spread and dominate large areas in a few short years. Invasive plant species displace native or desirable forest...

  17. A Guide to Bottomland Hardwood Restoration

    Science.gov (United States)

    2001-06-01

    floristically Ecological Importance of Understory diverse undergrowth may serve to pollinate flowers, Plants including those of trees. Undergrowth vegetation...Herbaceous plants include bedstraw, Variants and associated vegetation. Sycamore- violet, wild carrot, wild lettuce , amsonia, mint, legumes, pecan...elements of bottomland hardwood restoration such as species selection, site preparation, direct seeding, planting of seedlings, and alternative

  18. Labelling of rice seedlings and rice plants with 32P

    International Nuclear Information System (INIS)

    Achmad Nasroh, K.

    1989-01-01

    Labelling of rice seedlings and rice plants with 32 P. Labelled rice seedlings can be used to tag insect pests that feed on. Radioactivity counting of 32 P in the endosperm and in the shoot of rice seeds that soaked for 72 hours in KH 2 32 PO 4 solution of 1 μCi/ml were 29,300 and 9,500 cpm respectively. When these labelled seedlings were grown in unlabelled medium the radioactivity in the shoot increased. It was due to the 32 P that was translocated to the shoot from the endosperm. The 32 P translocation reached maximum about one week after the seedling were grown in the unlabelled medium. Labelled seedlings could also be produced by growing 5, 10 and 15 days old seedlings hydroponically in Kimura B solution containing 32 P. Ten days after growing, the radioactivity concentration of the seedlings stem reached about 115,000; 85,000 and 170,000 cpm/mg dry weight for the 5, 10 and 15 days old seedlings respectively. For the implementation of this method, 20 ml labelled Kimura B was needed for labelling of one seedling. The seedlings should be prepared in tap water. During the growth the 32 P in the labelled seedlings was distributed throughout the plant, so that new leaves and tillers became also radioactive. (author). 5 refs

  19. Biodegradable bags for the production of plant seedlings

    OpenAIRE

    Bilck,Ana Paula; Olivato,Juliana Bonametti; Yamashita,Fabio; Souza,José Roberto Pinto de

    2014-01-01

    The production of plant seedlings has traditionally used polyethylene bags, which are thrown out in the soil or burned after transplant because the large amount of organic material attached to the bags makes recycling difficult. Additionally, when a seedling is taken from the bag for transplant, there is the risk of root damage, which compromises the plant’s development. In this study, we developed biodegradable bags to be used in seedling production, and we verify their influence on the deve...

  20. Biodegradable bags for the production of plant seedlings

    Directory of Open Access Journals (Sweden)

    Ana Paula Bilck

    2014-10-01

    Full Text Available The production of plant seedlings has traditionally used polyethylene bags, which are thrown out in the soil or burned after transplant because the large amount of organic material attached to the bags makes recycling difficult. Additionally, when a seedling is taken from the bag for transplant, there is the risk of root damage, which compromises the plant’s development. In this study, we developed biodegradable bags to be used in seedling production, and we verify their influence on the development of Brazilian ginseng (Pfaffia glomerata (Spreng Pedersen, when the plant is planted without being removed from the bag. Both black and white biodegradable bags remained intact throughout the seedling production period (60 days. After being transplanted into containers (240 days, they were completely biodegraded, and there was no significant difference between the dry mass of these plants and that of plants that were transplanted without the bags. The plants that were cultivated without being removed from the polyethylene bags had root development difficulties, and the wrapping showed no signs of degradation. The use of biodegradable films is an alternative for the production of bags for seedlings, as these can then be transplanted directly into the soil without removing the bag, reducing the risk of damage to the roots during the moment of transplant.

  1. Light and soil humidity influencing oak seedling growth and physiology in mixed hardwood gaps

    Directory of Open Access Journals (Sweden)

    Raddi S

    2009-06-01

    Full Text Available In “S. Rossore, Migliarino, Massaciuccoli” Natural Park (Pisa, I six-month-old pedunculate oak seedlings (Quercus robur L. were transplanted within natural gaps of a mixed oak forest. Micro-environmental variability for radiation and water soil content were measured for 145 seedlings during the year. Irradiation relative to the open field (IR ranged from 5% to 57%. Seven classes of IR each with 20 seedlings were selected. Leaf mass per area was strongly influenced by IR. In the first 3 years survival was high (95, 76 and 75%, respectively and seedling reached 14±6 cm, 27±13 cm and 39±19 (sd cm of height. Even if IR and soil water content (SWC were negatively associated, indicating a lower SWC at the centre of the gaps, height and its relative growth rate increased with IR (explored range: 8-40% with a significant interaction with SWC in the 1st year, indicating the positive effect of soil moisture. In the 3rd year dimensional traits were higher in L+W+ (high light and humidity followed by L-W+ (low light and high humidity, L+W- and finally by L-W-. Summer drought typical of the Mediterranean climate was evaluated by chlorophyll fluorescence of PSII on apical leaves of seedlings and mature trees at the beginning (21 June and in mid-summer (20 July. While in June physiological traits did not differ between low and high IR, in mid-summer (at the peak of water-stress seedlings of the two highest light classes showed chronic photoinhibition (Fv/Fm<0.75 and an increase in thermal dissipation (D by constitutive term (Dc=1-Fv/Fm and by regulated mechanisms of dissipation through xanthophyll-cycle term (Dx. Moreover, in July seedling leaf physiology largely differed with IR: leaves acclimated to high IR have higher photosynthetic potentialities, as shown by electron transport rate (ETR and quantum yield (P at saturating light maintained by an increase of the fraction of open reaction centres (qP, counterbalancing the efficiency decrease of the

  2. Thirteen Year Loblolly Pine Growth Following Machine Application of Cut-Stump Treament Herbicides For Hardwood Stump-Sprout Control

    Science.gov (United States)

    Clyde G. Vidrine; John C. Adams

    2002-01-01

    Thirteen year growth results of 1-0 out-planted loblolly pine seedlings on nonintensively prepared up-land mixed pine-hardwood sites receiving machine applied cut-stump treatment (CST) herbicides onto hardwood stumps at the time of harvesting is presented. Plantation pine growth shows significantly higher growth for pine in the CST treated plots compared to non-CST...

  3. Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide

    International Nuclear Information System (INIS)

    Davis, D.D. Skelly, J.M.

    1992-01-01

    In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests

  4. Tree planting in Haiti: How to plant and care for your nursery grown seedlings

    Science.gov (United States)

    Kyrstan Hubbel; Yvonne Barkley; Jeremiah R. Pinto; R. Kasten Dumroese; Sabine Deristin; Raymond Joseph; Randy Brooks; Anthony S. Davis

    2016-01-01

    Seedlings need the right amounts of sunlight, water and nutrients to live and grow into healthy trees. Different types of trees have different requirements, so seedlings will need planting sites that meet all of their requirements. For example, pine trees need full sun, a moderate amount of water and a certain combination of nutrients to grow into healthy trees. If you...

  5. Gene expression in plant lipid metabolism in Arabidopsis seedlings.

    Directory of Open Access Journals (Sweden)

    An-Shan Hsiao

    Full Text Available Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3, DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1 and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6 in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1 and LATE ELONGATED HYPOCOTYL (LHY from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis.

  6. Economic rationale for planting less trees in the face of seedling mortality

    Science.gov (United States)

    Thomas J. Dean; S. Joseph Chang

    2002-01-01

    Simple economic analyses are used to demonstrate that planting extra trees to compensate for initial seedling mortality can actually reduce the profit expected from a pine plantation. At a 6-percent interest rate, the cost of planting 15 or 25 percent additional seedlings compounded to the end of a 30-year rotation exceeds the revenue lost to these rates of seedling...

  7. Fifteen-Year Growth of Six Planted Hardwood Species on Sharkey Clay Soil

    Science.gov (United States)

    Roger M. Krinard; Harvey E. Kennedy

    1987-01-01

    Six hardwood species planted on Sharkey clay soil that had been disked the first 5 years for weed control were significantly taller at age 5 when compared to species grown on mowed sites. By age 15, there were no differences in heights within species except for sweet pecan. Average heights by species at age 15 were: cottonwood (Populus deltoides...

  8. Nursery stock quality as an indicator of bottomland hardwood forest restoration success in the Lower Mississippi River Alluvial Valley

    Science.gov (United States)

    Douglass F. Jacobs; Rosa C. Goodman; Emile S. Gardiner; K Frances Salifu; Ronald P. Overton; George Hernandez

    2012-01-01

    Seedling morphological quality standards are lacking for bottomland hardwood restoration plantings in the Lower Mississippi River Alluvial Valley, USA, which may contribute toward variable restoration success. We measured initial seedling morphology (shoot height, root collar diameter, number of first order lateral roots, fresh mass, and root volume), second year field...

  9. Naturally seeded versus planted ponderosa pine seedlings in group-selection openings

    Science.gov (United States)

    Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson

    2009-01-01

    The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer dependson the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In thisside-by-side study, the natural pine seedlings originated...

  10. Rare Plants of Southeastern Hardwood Forests and the Role of Predictive Modeling

    International Nuclear Information System (INIS)

    Imm, D.W.; Shealy, H.E. Jr.; McLeod, K.W.; Collins, B.

    2001-01-01

    Habitat prediction models for rare plants can be useful when large areas must be surveyed or populations must be established. Investigators developed a habitat prediction model for four species of Southeastern hardwood forests. These four examples suggest that models based on resource and vegetation characteristics can accurately predict habitat, but only when plants are strongly associated with these variables and the scale of modeling coincides with habitat size

  11. Growth of short-day treated spruce seedlings planted throughout British Columbia. FRDA report No. 209

    Energy Technology Data Exchange (ETDEWEB)

    Krasowski, M.J.; Letchford, T.; Eastham, A.M.

    1993-01-01

    Short photoperiod (SD) treatments of conifer seedlings induce bud dormancy and enhance cold acclimation. Such treatments are also useful in regulating seedling height to meet a specific target and in preparing seedlings for lifting at a desirable time. These trials were designed to compare different SD-treated and untreated stock in terms of their annual height and ground-line stem diameter increments, 1st year post-planting terminal bud phenology, and seedling survival and condition.

  12. Fifth workshop on seedling physiology and growth problems in oak plantings (abstracts).

    Science.gov (United States)

    Janette R. Thompson; Richard C. Schultz; J.W. Van Sambeek

    1993-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 30 abstracts.

  13. Ninth workshop on seedling physiology and growth problems in oak plantings (abstracts)

    Science.gov (United States)

    D.R. Weigel; J.W. Van Sambeek; C.H., eds. Michler

    2005-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 26 abstracts.

  14. Tenth workshop on seedling physiology and growth problems in oak plantings

    Science.gov (United States)

    Brian Roy Lockhart; Emile S. Gardiner; Daniel C. Dey

    2008-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 15 abstracts.

  15. Can cover data be used as a surrogate for seedling counts in regeneration stocking evaluations in northern hardwood forests?

    Science.gov (United States)

    Todd E. Ristau; Susan L. Stout

    2014-01-01

    Assessment of regeneration can be time-consuming and costly. Often, foresters look for ways to minimize the cost of doing inventories. One potential method to reduce time required on a plot is use of percent cover data rather than seedling count data to determine stocking. Robust linear regression analysis was used in this report to predict seedling count data from...

  16. Time interval between cover crop termination and planting influences corn seedling disease, plant growth, and yield

    Science.gov (United States)

    Experiments were established in controlled and field environment to evaluate the effect of time intervals between cereal rye cover crop termination and corn planting on corn seedling disease, corn growth, and grain yield in 2014 and 2015. Rye termination dates ranged from 25 days before planting (DB...

  17. Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants.

    Science.gov (United States)

    Merrild, Marie P; Ambus, Per; Rosendahl, Søren; Jakobsen, Iver

    2013-10-01

    Common mycorrhizal networks (CMNs) influence competition between plants, but reports regarding their precise effect are conflicting. We studied CMN effects on phosphorus (P) uptake and growth of seedlings as influenced by various disruptions of network components. Tomato (Solanum lycopersicon) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of (32)P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre-established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed improved growth. Solitary seedlings growing in a network patch that had been severed from the CMN also grew much better than seedlings of the corresponding CMN. Interspecific and size-asymmetric competition between plants may be amplified rather than relaxed by CMNs that transfer P to large plants providing most carbon and render small plants P deficient. It is likely that grazing or senescence of the large plants will alleviate the network-induced suppression of seedling growth. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  18. Survival of planted tupelo seedlings in F- and H-Area tree-kill zones

    International Nuclear Information System (INIS)

    Nelson, E.A.; Rogers, V.A.

    1995-01-01

    Swamp tupelo seedlings were planted in four areas which experienced previous tree mortality at the seeplines of the F- and H-Area Seepage Basins. The sites represented a range in severity of impact and stage of recovery. Seedlings were planted in February of 1994 and followed through the first growing season in the field. Survival on all sites through the first growing season was excellent, with greater than 92% of the seedlings still alive. Most seedlings appeared healthy with few external signs of stress. The performance of the seedlings will be followed in subsequent years to determine the physical state of the soil environment on seedling growth. Hopefully, the results will indicate that artificial reforestation can begin on similarly impacted sites prior to the beginning of natural revegetation of the site

  19. Influence of overstory density on ecophysiology of red oak (Quercus rubra) and sugar maple (Acer saccharum) seedlings in central Ontario shelterwoods

    Science.gov (United States)

    William C. Parker; Daniel C. Dey

    2008-01-01

    A field experiment was established in a secondgrowth hardwood forest dominated by red oak (Quercus rubra L.) to examine the effects of shelterwood overstory density on leaf gas exchange and seedling water status of planted red oak, naturally regenerated red oak and sugar maple (Acer saccharum Marsh.) seedlings during the first...

  20. Factors Affecting Planting Depth and Standing of Rice Seedling in Parachute Rice Transplanting

    Science.gov (United States)

    Astika, I. W.; Subrata, I. D. M.; Pramuhadi, G.

    2018-05-01

    Parachute rice transplanting is a simple and practical rice transplanting method. It can be done manually or mechanically, with various possible designs of machines or tools. This research aimed at quantitatively formulating related factors to the planting depth and standing of rice seedling. Parachute seedlings of rice were grown at several sizes of parachute soil bulb sizes. The trays were specially designed with a 3D printer having bulb sizes 7, 8, 9, 10 mm in square sides and 15 mm depth. At seedling ages of 8-12 days after sowing the seedling bulbs were drops into puddled soil. Soil hardness was set at 3 levels of hardness, measured in hardness index using golf ball test. Angle of dropping was set at 3 levels: 0°, 30°and 45° from the vertical axis. The height of droppings was set at 100 cm, 75 cm, and 50 cm. The relationship between bulb size, height of dropping, soil hardness, dropping angle and planting depth was formulated with ANN. Most of input variables did not significantly affect the planting depth, except that hard soil significantly differs from mild soil and soft soil. The dropping also resulted in various positions of the planted seedlings: vertical standing, sloped, and falling. However, at any position of the planted seedlings, the seedlings would recover themselves into normally vertical position. With this result, the design of planting machinery, as well as the manual planting operation, can be made easier.

  1. The vernal dam: Plant-microbe competition for nitrogen in northern hardwood forests

    International Nuclear Information System (INIS)

    Zak, D.R.; Groffman, P.M.; Pregitzer, K.S.; Tiedje, J.M.; Christensen, S.

    1990-01-01

    Nitrogen (N) uptake by spring ephemeral communities has been proposed as a mechanism that retains N within northern hardwood forests during the season of maximum loss. To understand better the importance of these plants in retaining N, the authors followed the movement of 15 NH 4 + and 15 NO 3 - into plant and microbial biomass. Two days following isotope addition, microbial biomass represented the largest labile pool of N and contained 8.5 times as much N as Allium tricoccum L. biomass. Microbial immobilization of 15 N was 10-20 times greater than uptake by A. tricoccum. Nitrification of 15 NH 4 + was five times lower in cores containing A. tricoccum compared to those without the spring ephemeral. Spring N retention within northern hardwood forests cannot be fully explained by plant uptake because microbial immobilization represented a significantly larger sink for N. Results suggest that plant and microbial uptake of NH 4 + may reduce the quantity of substrate available for nitrification and thereby lessen the potential for NO 3 - loss via denitrification and leaching

  2. Grass or fern competition reduce growth and survival of planted tree seedlings

    Science.gov (United States)

    Larry H. McCormick; Todd W. Bowersox

    1997-01-01

    Bareroot seedlings of northern red oak, white ash, yellow-poplar and white pine were planted into herbaceous communities at three forested sites in central Pennsylvania that were clearcut 0 to 1 year earlier. Seedlings were grown 4 years in the presence and absence of either an established grass or hay-scented fern community. Survival and height growth were measured...

  3. Root-collar diameter and third-year survival of three bottomland hardwoods planted on former agricultural fields in the Lower Mississippi Alluvial Valley

    Science.gov (United States)

    Emile S. Gardiner; Douglass F. Jacobs; Ronald P. Overton; George Hernandez

    2009-01-01

    Athough the Lower Mississippi Alluvial Valley (LMAV) has experienced substantial afforestation of former agricultural fields during the past 2 decades, seedling standards that support satisfactory outplanting performance of bottomland hardwood tree species are not available. A series of experimental plantations, established on three afforestation sites in the LMAV,...

  4. Quantifying structural and physiological controls on variation in canopy transpiration among planted pine and hardwood species in the southern Appalachians

    Science.gov (United States)

    Chelcy R. Ford; Robert M. Hubbard; James M. Vose

    2010-01-01

    Recent studies have shown that planted pine stands exhibit higher evapotranspiration (ET) and are more sensitive to climatic conditions compared with hardwood stands. Whether this is due to management and stand effects, biological effects or their interaction is poorly understood. We estimated growing season canopy- and sap flux-scaled leaf-level transpiration (Ec and...

  5. The Lr34 adult plant rust resistance gene provides seedling resistance in durum wheat without senescence.

    Science.gov (United States)

    Rinaldo, Amy; Gilbert, Brian; Boni, Rainer; Krattinger, Simon G; Singh, Davinder; Park, Robert F; Lagudah, Evans; Ayliffe, Michael

    2017-07-01

    The hexaploid wheat (Triticum aestivum) adult plant resistance gene, Lr34/Yr18/Sr57/Pm38/Ltn1, provides broad-spectrum resistance to wheat leaf rust (Lr34), stripe rust (Yr18), stem rust (Sr57) and powdery mildew (Pm38) pathogens, and has remained effective in wheat crops for many decades. The partial resistance provided by this gene is only apparent in adult plants and not effective in field-grown seedlings. Lr34 also causes leaf tip necrosis (Ltn1) in mature adult plant leaves when grown under field conditions. This D genome-encoded bread wheat gene was transferred to tetraploid durum wheat (T. turgidum) cultivar Stewart by transformation. Transgenic durum lines were produced with elevated gene expression levels when compared with the endogenous hexaploid gene. Unlike nontransgenic hexaploid and durum control lines, these transgenic plants showed robust seedling resistance to pathogens causing wheat leaf rust, stripe rust and powdery mildew disease. The effectiveness of seedling resistance against each pathogen correlated with the level of transgene expression. No evidence of accelerated leaf necrosis or up-regulation of senescence gene markers was apparent in these seedlings, suggesting senescence is not required for Lr34 resistance, although leaf tip necrosis occurred in mature plant flag leaves. Several abiotic stress-response genes were up-regulated in these seedlings in the absence of rust infection as previously observed in adult plant flag leaves of hexaploid wheat. Increasing day length significantly increased Lr34 seedling resistance. These data demonstrate that expression of a highly durable, broad-spectrum adult plant resistance gene can be modified to provide seedling resistance in durum wheat. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  6. Sixth workshop on seedling physiology and growth problems in oak plantings (abstracts); 1995 September 18-20; Tomahawk, WI.

    Science.gov (United States)

    Ronald M. Teclaw

    1996-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination ,and natural regeneration for oaks are described in 29 abstracts.

  7. Eighth workshop on seedling physiology and growth problems in oak plantings (abstracts). 2001 September 9-12; Hiwassee, GA.

    Science.gov (United States)

    S. Sung; P.P. Kormanik; W.J. Ostrosina; J.G. Isebrands

    2002-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 21 abstracts.

  8. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2013-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of "1"3"7Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of "1"3"7Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm"3) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of "1"3"7Cs in the rice seedlings ranged from 150 to 1900 Bq kg"-"1, and that in brown rice and sunflower ranged from 2 to 880 Bq kg"-"1 and from 580 to 3900 Bq kg"-"1, respectively. The Spearman's rank correlation coefficient between the measured concentration of "1"3"7Cs in rice seedlings and the measured concentration of "1"3"7Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of "1"3"7Cs from soil to plants over a longer period of time. (author)

  9. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2012-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of 137 Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of 137 Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm 3 ) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of 137 Cs in the rice seedlings ranged from 150 to 1900 Bq kg -1 , and that in brown rice and sunflower ranged from 2 to 880 Bq kg -1 and from 580 to 3900 Bq kg -1 , respectively. The Spearman's rank correlation coefficient between the measured concentration of 137 Cs in rice seedlings and the measured concentration of 137 Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of 137 Cs from soil to plants over a longer period of time. (author)

  10. Photosynthetic Responses of Seedlings of two Indigenous Plants ...

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. The potential role of exotic tree plantations in facilitating successional processes on degraded areas was evaluated in southern Ethiopia, Munessa-Shashemene forest, by examining photosynthetic responses of Bersamaabyssinica Fres. and Croton macrostachyusDel. seedlings naturally grown inside ...

  11. Limitations to postfire seedling establishment: The role of seeding technology, water availability, and invasive plant abundance

    Science.gov (United States)

    Jeremy J. James; Tony Svejcar

    2010-01-01

    Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abundance, and seeding technology influence postfire seedling establishment...

  12. Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

    Directory of Open Access Journals (Sweden)

    Daniel Lord

    2013-06-01

    Full Text Available Open lichen woodlands (LWs are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spruce-feathermoss (BSFM stands. After one year, seedling survival and nutritional status were equivalent among stand types but despite higher root elongation index (REI, planted seedlings in LWs had lower relative growth rate, smaller total biomass and stem diameter than those in BSFM stands. Soil fertility variables, soil temperature, nor seedling water potential, helped at explaining this early growth response. Disc scarification significantly improved seedling first-year survival, biomass and foliar nutrient concentrations of P, Ca, and Mg. Smaller planting stock showed higher REI, higher shoot water potential, and higher foliar nutrient concentration of all but one of the measured nutrients (N, P, K and Mg. Hence, preliminary results suggest that planting of smaller containerized black spruce stock, combined with disc scarification, shows potential for afforestation of unproductive LWs. The impact of the lichen mat and other potential growth limiting factors on afforestation of these sites requires further investigation.

  13. GARDEN CRESS GERMINABILITY AND SEEDLING VIGOUR AFTER TREATMENT WITH PLANT EXTRACTS

    Directory of Open Access Journals (Sweden)

    Miroslav Lisjak

    2015-12-01

    Full Text Available The usage of biologically active and environmentally friendly compounds has increasingly important role in the primary food production. This study was conducted in order to examine the impact of five commercial plant extracts on the seed vigour of garden cress (Lepidium sativum L.. The applied plant extracts significantly increased the germination. The highest fresh weight of seedlings, and also the lowest dry matter accumulation were observed in the treatment KE-plantasalva® without the sea salt addition. Equisetum extract inhibited the root elongation and resulted in the highest percentage of dry matter accumulated in seedlings, but also the lowest fresh weight.

  14. Planting and care of fine hardwood seedlings: Fertilizing, pruning, and thinning

    Science.gov (United States)

    James McKenna; Keith Woeste

    2004-01-01

    This publication outlines the cultural operations of pruning, fertilizing, and thinning that can greatly enhance the timber value of a plantation. This summary is based on the findings of many individuals. While there are alternatives to many of the recommended practices and differences of opinion existing among professionals, our purpose is to give the landowner a...

  15. Potential impacts of using sewage sludge biochar on the growth of plant forest seedlings

    Directory of Open Access Journals (Sweden)

    Maria Isidoria Silva

    Full Text Available ABSTRACT: Sewage sludge has long been successfully used in the production of nursery plants; however, some restriction may apply due to its high pathogenic characteristics. The process of charring the organic waste significantly reduces that undesired component and may be as effective as the non-charred residue. The aim of this study was to evaluate the effect of sewage sludge biochar on the growth and morphological traits of eucalyptus ( Eucalyptus grandis L. seedlings, and compare results with those observed when using uncharred sewage sludge. Treatments were arranged in a completely randomized design, in a 2 x 2 factorial scheme, with four replications. Charred and non-charred sewage sludge were tested with and without NPK addition. A control treatment was also evaluated. Ten weeks old eucalyptus seedlings were transferred to the pots and grew for eight weeks. Chlorophyll content, plant height and stem diameter were measured at 0, 30 and 60 days after transplant. Shoot and root biomass were measured after plant harvest. Dickson Quality Index was calculated to evaluate the overall quality of seedlings. Biochar was effective in improving the seedlings quality, and had similar effects as the non-charred waste. Therefore, sewage sludge biochar has the potential to improve the process of production of forest species seedlings and further reduce the environmental risks associated with the use of non-charred sewage sludge.

  16. Do seedling functional groups reflect ecological strategies of woody plant species in Caatinga?

    Directory of Open Access Journals (Sweden)

    Tatiane Gomes Calaça Menezes

    2017-11-01

    Full Text Available ABSTRACT It is assumed that morphological traits of seedlings reflect different strategies in response to environmental conditions. The ecological significance of this has been widely documented in rainforests, where habitat structure and species interactions play an important role in community assembly. However, in seasonally dry ecosystems, where environmental filtering is expected to strongly influence community structure, this relationship is poorly understood. We investigated this relationship between functional groups of seedlings and life history traits and tested whether functional group predicts the ecological strategies employed by woody species to deal with the stressful conditions in seasonally dry ecosystems. Seedling functional groups, life history traits and traits that reflect ecological strategies for occupying seasonally dry environments were described for twenty-six plant species. Seedlings of species from the Caatinga vegetation exhibited a functional profile different from that observed in rainforests ecosystems. Phanerocotylar-epigeal seedlings were the most frequently observed groups, and had the largest range of ecological strategies related to dealing with seasonally dry environments, while phanerocotylar-hypogeal-reserve seedlings exhibited an increase in frequency with seasonality. We discuss these results in relation to those observed in other tropical forests and their ecological significance in seasonally dry environments.

  17. Survivel, growth, and nutrition of tree seedlings fertilized at planting on Andisol soils in Iceland

    DEFF Research Database (Denmark)

    Oskarsson, Hreinn; Sigurgeirsson, Adalsteinn; Raulund-Rasmussen, Karsten

    2006-01-01

    seedlings, compared to control seedlings. It is concluded that fertilization during afforestation in Iceland and other areas in the world with similar climatic and soil properties could make the difference between plantation success or failure. Growth; Survival; Foliar nutrient concentration; Frost heaving......A field trial was carried out in 1995 to study the effect of fertilization at planting on the survival, growth, and nutrition of tree seedlings planted on Andisol soils at two sites in South Iceland. Nine fertilizer treatments were tested on three tree species Betula pubescens Ehrh., Larix sibirica...... survival and growth. Larger amounts of N increased mortality during the first year. Fertilized trees were less subject to frost heaving than untreated trees. In the year following application of NPK fertilizer the effect was insignificant on the foliar concentration of macronutrients of the fertilized...

  18. Germination and seedling establishment of spiny hopsage in response to planting date and seedbed environment

    Science.gov (United States)

    Nancy L. Shaw; Marshall R. Haferkamp; Emerenciana G. Hurd

    1994-01-01

    Reestablishment of spiny hopsrge (Grayia spinosa [Hook.] Moq.) in the shrub steppe requires development of appropriate seeding technology. We examined the effect of planting date and seedbed environment on germination and seedling establishment of 2 seed sources at 2 southwestern Idaho sites. Seedbeds were prepared by rototilling. In 1987-88, seeds...

  19. Effects of temperature, moisture and soil type on seedling emergence and mortality of riparian plant species

    NARCIS (Netherlands)

    ter Heerdt, Gerard N. J.; Veen, Ciska G.F.; van der Putten, Wim H.; Bakker, Jan P.

    Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in the

  20. Effects of temperature, moisture and soil type on seedling emergence and mortality of riparian plant species

    NARCIS (Netherlands)

    Heerdt, ter Gerard N.J.; Veen, Ciska G.F.; Putten, van der Wim H.; Bakker, Jan P.

    2017-01-01

    Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in the

  1. Effects of temperature, moisture and soil type on seedling emergence and mortality of riparian plant species

    NARCIS (Netherlands)

    Ter Heerdt, Gerard N.J.; Veen, G.F.; Van der Putten, Wim H.; Bakker, Jan P.

    Abstract Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in

  2. Physiological responses of planting frozen and thawed Douglas-fir seedlings

    Science.gov (United States)

    M. Anisul Islam; Kent G. Apostol; Douglass F. Jacobs; R. Kasten Dumroese

    2008-01-01

    We studied the short-term (7-day) physiological responses of planting thawed and frozen root plugs of Douglas-fir (Pseudotsuga menziesii) seedlings in 2 separate experiments under cool-moist and warm-dry growing conditions, respectively. Our results showed that shoot water potential, root hydraulic conductance, net photosynthesis (A), and...

  3. Photoinduced toxicity of fluoranthene on germination and early development of plant seedling.

    Science.gov (United States)

    Kummerová, Marie; Kmentová, Eva

    2004-07-01

    The influence of light on phytotoxicity of increased concentration (2, 5, 10 mg/l) of intact fluoranthene (FLT) and photomodified fluoranthene (phFLT) diluted in experimental solutions was investigated. The germination rate of lettuce (Lactuca sativa L.), onion (Allium cepa L.) and tomato (Lycopersicum esculentum L.) seeds and some parameters of seedlings primary growth of these plant species were used as laboratory indicators of phytotoxicity. Among them a length of root and shoot, their dry weight and a content of photosynthetic pigments in shoot were measured. The results demonstrated that the higher concentration (5 and 10 mg/l) of FLT and especially of phFLT significantly inhibited the germination rate of seeds and the length of root and shoot seedlings of all plant species. Decreased production of biomass expressed by dry weight of root and shoot was found in lettuce seedlings under the inhibitory effect of FLT and phFLT. An increased concentration of FLT and phFLT did not exhibit an unambiguous effect on the content of photosynthetic pigments in shoot of experimental plants. Only the highest concentration (10 mg/l) of FLT significantly increased content of chlorophylls a and b in lettuce, onion and tomato plants and content of carotenoids in lettuce and onion. Light intensified a significant inhibitory effect of phFLT in the most testified parameters of germination and seedling growth.

  4. Invasive plant suppresses the growth of native tree seedlings by disrupting belowground mutualisms.

    Directory of Open Access Journals (Sweden)

    Kristina A Stinson

    2006-05-01

    Full Text Available The impact of exotic species on native organisms is widely acknowledged, but poorly understood. Very few studies have empirically investigated how invading plants may alter delicate ecological interactions among resident species in the invaded range. We present novel evidence that antifungal phytochemistry of the invasive plant, Alliaria petiolata, a European invader of North American forests, suppresses native plant growth by disrupting mutualistic associations between native canopy tree seedlings and belowground arbuscular mycorrhizal fungi. Our results elucidate an indirect mechanism by which invasive plants can impact native flora, and may help explain how this plant successfully invades relatively undisturbed forest habitat.

  5. Responses of hybrid poplar clones and red maple seedlings to ambient O3 under differing light within a mixed hardwood forest

    International Nuclear Information System (INIS)

    Wei, C.; Skelly, J.M.; Pennypacker, S.P.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E.; Davis, D.D.

    2004-01-01

    The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O 3 ) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O 3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O 3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 μmol m -2 s -1 , respectively. Ambient O 3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001growing season. Percentage of total leaf area affected (%LAA) was positively correlated with cumulative O 3 exposures. More severe foliar injury was observed on plants grown within the full shade and partial shade plots than those observed on plants grown within the sun plot. Lower light availability within the partial shade and full shade plots significantly decreased net photosynthetic rate (Pn) and stomatal conductance (g wv ). The reductions in Pn were greater than reductions in g wv , which resulted in greater O 3 uptake per unit Pn in plants grown within the partial shade and full shade plots. Greater O 3 uptake per unit Pn was consistently associated with more severe visible foliar injury in all species and/or clones regardless of differences in shade tolerance. These studies suggest that plant physiological responses to O 3 exposure are likely complicated due to multiple factors under natural forest conditions. - Under natural forest conditions and ambient O 3 exposures, available light plays a significant role in determining O 3 uptake and

  6. ECOTOXICITY AND PHYTOTOXICITY OF PLANT PROTECTION PRODUCTS TO RHIZOSPHERE FUNGI AND WINTER WHEAT SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Anna Daria Stasiulewicz-Paluch

    2015-11-01

    Full Text Available Registration of plant protection products involves the analysis of their effects on soil microorganisms. The residues of plant protection products penetrate the soil, but their impact on fungi remains scarcely researched. In this study, the influence of selected plant protection products on the abundance of rhizosphere-dwelling fungi and the growth of winter wheat seedlings was evaluated under greenhouse conditions. The analysed plant protection products had an inhibitory effect on the growth of filamentous fungi in the rhizosphere, whereas yeasts were resistant to those products applied to soil. Tebuconazole exerted the strongest suppressive effect on the growth of filamentous fungi, and propiconazole was characterized by the greatest phytotoxic activity against winter wheat seedlings. Azoxystrobin had the weakest ecotoxic and phytotoxic effects, and its application to soil usually led to a rapid increase in the counts of fungi of the genus Acremonium.

  7. Frost heaving of planted tree seedlings in the boreal forest of northern Sweden

    International Nuclear Information System (INIS)

    Goulet, France

    2000-01-01

    Frost heaving can be a leading cause of tree seedling mortality in many places in the boreal forest of Northern Sweden. The aim of this investigation was to improve our understanding of frost heaving of planted tree seedlings as related to snow cover, scarification, planting methods and soil types. The thesis is based on a review paper, three field experiments and one laboratory experiment. The experiments focus on different methods to control frost heaving of forest tree seedlings and on a number of factors affecting the extent of frost heaving. The review paper identifies the many aspects of frost heaving of forest tree seedlings and agricultural crops based on an intensive review of the research contributions made during the last century. Even if many investigations have been carried out with the aim to decrease the extent of frost heaving, very little quantitative results are available for tree seedlings. In a field experiment, the choice of planting positions was effective in decreasing frost heaving of planted seedlings following mounding or disc-trenching. Seedlings planted in the depressions were largely affected by frost heaving with a maximal vertical displacement of 5.4 cm while frost heaving did not occur on the top of the mound. On the other hand, the planting time and planting depth had no influence on the extent of frost heaving. In another field experiment the size of the scarified patches was strongly correlated to frost heaving which reached between 7.6 and 11.5 cm in 4 and 8-dm patches compared to between 4.4 and 5.3 in non-scarified soil and in a 1-dm patch. Ground vegetation probably decreases the diurnal temperature variation and the number of freezing-thawing cycles. The duration and magnitude of frost temperatures, the frost hour sum, increased with patch size. The difference between the 8-dm and 1-dm patch increased to 2064 hour-degrees at the end of the winter. In larger patches, the planting depth seemed to be effective in reducing the

  8. Frost heaving of planted tree seedlings in the boreal forest of northern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Goulet, France

    2000-07-01

    Frost heaving can be a leading cause of tree seedling mortality in many places in the boreal forest of Northern Sweden. The aim of this investigation was to improve our understanding of frost heaving of planted tree seedlings as related to snow cover, scarification, planting methods and soil types. The thesis is based on a review paper, three field experiments and one laboratory experiment. The experiments focus on different methods to control frost heaving of forest tree seedlings and on a number of factors affecting the extent of frost heaving. The review paper identifies the many aspects of frost heaving of forest tree seedlings and agricultural crops based on an intensive review of the research contributions made during the last century. Even if many investigations have been carried out with the aim to decrease the extent of frost heaving, very little quantitative results are available for tree seedlings. In a field experiment, the choice of planting positions was effective in decreasing frost heaving of planted seedlings following mounding or disc-trenching. Seedlings planted in the depressions were largely affected by frost heaving with a maximal vertical displacement of 5.4 cm while frost heaving did not occur on the top of the mound. On the other hand, the planting time and planting depth had no influence on the extent of frost heaving. In another field experiment the size of the scarified patches was strongly correlated to frost heaving which reached between 7.6 and 11.5 cm in 4 and 8-dm patches compared to between 4.4 and 5.3 in non-scarified soil and in a 1-dm patch. Ground vegetation probably decreases the diurnal temperature variation and the number of freezing-thawing cycles. The duration and magnitude of frost temperatures, the frost hour sum, increased with patch size. The difference between the 8-dm and 1-dm patch increased to 2064 hour-degrees at the end of the winter. In larger patches, the planting depth seemed to be effective in reducing the

  9. Can environmental variation affect seedling survival of plants in northeastern Mexico?

    Directory of Open Access Journals (Sweden)

    García Jaime F.

    2011-01-01

    Full Text Available The effects of global warming increase the frequency and intensity of many climate events such as rainfall. We evaluated the effects of environmental conditions on early stage seedling survival of the native thorn scrub species Caesalpinia mexicana A. Gray, Celtis pallida Torr., Cordia boissieri A. DC., and Ebenopsis ebano (Berland. Barneby and J.W. Grimes, during the summer of 2009 and 2010. The experimental design had two factors, two levels of rainfall and three microhabitats of thorn scrub: (i open interspace, (ii thorn scrub edge and (iii under the canopy of dense thorn scrub. In dense thorn scrub, seedling survival was higher for Caesalpinia mexicana and Celtis pallida, and for Cordia boissieri and Ebenopsis ebano seedling survival was higher in dense thorn scrub and thorn scrub edge. The effect of rainfall on seedling survival depended on the year. Rainfall in 2010 and dense thorn scrub increased seedling survival of native species. For survival, the limiting factors of microhabitats appear to change across the years. Besides rainfall events, biological aspects like competition and mycorrhiza effects would need to be considered in models of plant establishment.

  10. Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

    NARCIS (Netherlands)

    Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

    Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

  11. [Comparative study on alkaloids of tissue-culture seedling and wild plant of Dendrobium huoshanense ].

    Science.gov (United States)

    Chen, Nai-dong; Gao, Feng; Lin, Xin; Jin, Hui

    2014-06-01

    To compare the composition and content of alkaloid of Dendrobium huoshanense tissue-culture seedling and wild plant. A comparative evaluation on the quality was carried out by HPLC and TLC methods including the composition and the content of alkaloids. Remarkable variation existed in the two kinds of Dendrobium huoshanense. For the tissue-culture plant, only two alkaloids were checked out by both HPLC and TLC while four alkaloids were observed in the wild plant. The alkaloid content of tissue-culture seedling and wild plant was(0. 29 ± 0. 11)%o and(0. 43 ± 0. 15) %o,respectively. Distinguished difference is observed in both composition and content of alkaloids from the annual shoots of different provenances of Dendrobium huoshanense. It suggested that the quality of tissue-culture seedling of Dendrobium huoshanense might be inconsistent with the wild plant. Furthermore, the established alkaloids-knock-out HPLC method would provide a new research tool on quality control of Chinese medicinal materials which contain unknown alkaloids.

  12. Phylogenetic and Functional Diversity of Fleshy-Fruited Plants Are Positively Associated with Seedling Diversity in a Tropical Montane Forest

    Directory of Open Access Journals (Sweden)

    Marcia C. Muñoz

    2017-08-01

    Full Text Available Mutualistic interactions between plants and animals can affect both plant and animal communities, and potentially leave imprints on plant demography. Yet, no study has simultaneously tested how trait variation in plant resources shapes the diversity of animal consumers, and how these interactions influence seedling recruitment. Here, we analyzed whether (i phylogenetic diversity and functional diversity of fruiting plants were correlated with the corresponding diversity of frugivorous birds, and (ii whether phylogenetic diversity and functional identity of plant and bird communities influenced the corresponding diversity and identity of seedling communities. We recorded mutualistic interactions between fleshy-fruited plants and frugivorous birds and seedling communities in 10 plots along an elevational gradient in the Colombian Andes. We built a phylogeny for plants/seedlings and birds and measured relevant morphological plant and bird traits that influence plant-bird interactions and seedling recruitment. We found that phylogenetic diversity and functional diversity of frugivorous birds were positively associated with the corresponding diversities of fruiting plants, consistent with a bottom-up effect of plants on birds. Moreover, the phylogenetic diversity of seedlings was related to the phylogenetic diversity of plants, but was unrelated to the phylogenetic diversity of frugivorous birds, suggesting that top-down effects of animals on seedlings were weak. Mean seed mass of seedling communities was positively associated with the mean fruit mass of plants, but was not associated with the mean avian body mass in the frugivore communities. Our study shows that variation in the traits of fleshy-fruited plants was associated with the diversity of frugivorous birds and affected the future trajectory of seedling recruitment, whereas the morphological traits of animal seed dispersers were unrelated to the phylogenetic and functional structure of

  13. The Effect of Salinity on Seed Germination and Seedling Growth of Four Medicinal Plant Species

    Directory of Open Access Journals (Sweden)

    H Javadi

    2014-07-01

    Full Text Available To study the effect of salinity stress on seed germination and seedling growth of four medicinal plants, Nigella sativa L., Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus L. an experiment was conducted in the botany laboratory of Islamic Azad University, Birjand branch. A completely randomized design (CRD with 3 replications was used as separately for each species. Treatments were consisted of six salinity (NaCl concentrations (0, 4, 8, 12, 16 and 20 dS m-1. The measured traits were root, shoot and seedling length, dry and fresh weight of seedling, germination rate and percent, seed vigor index, seedling water content and root/ shoot ratio. Salinity stress reduced significantly shoot, root and seedling length of the species. Increasing of salinity stress declined dry and fresh weight of Trigonella foenum and Nigella sativa L. and dry weight of Cannabis sativa L.. Seedling water content and root/ shoot ratio of Nigella sativa L. increased in salinity treatments. Increasing of salinity stress declined germination rate and percent in Nigella sativa L., but in other species (Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus only germination rate decreased. Trigonella foenum graecum germinated completely (%100 in all salinity treatments. Increasing of salinity until 16 dS m-1 reduced seed germination of Nigella sativa. Seed germination of Nigella sativa did not occurred in the highest salinity stress (20 dS m-1. Totally the results showed that in the germination stage, Trigonella foenum graecum and Cannabis sativa were relatively tolerate to salinity stress but Nigella sativa L. was the most sensitive one

  14. A plant growth-promoting symbiosis between Mycena galopus and Vaccinium corymbosum seedlings.

    Science.gov (United States)

    Grelet, Gwen-Aëlle; Ba, Ren; Goeke, Dagmar F; Houliston, Gary J; Taylor, Andy F S; Durall, Daniel M

    2017-11-01

    Typically, Mycena species are viewed as saprotrophic fungi. However, numerous detections of Mycena spp. in the roots of green plants suggest that a continuum from saprotrophy to biotrophy could exist. In particular, mycenoid species have repeatedly been found in Ericaceae plant roots. Our study asked whether (1) Mycena species are commonly found in the roots of green Ericaceae plants; (2) Mycena sequences are limited to a single group/lineage within the genus; and (3) a Mycena sp. can behave as a beneficial root associate with a typical ericoid mycorrhizal plant (Vaccinium corymbosum), regardless of how much external labile carbon is available. We detected Mycena sequences in roots of all sampled Ericaceae plants. Our Mycena sequences clustered in four different groups distributed across the Mycena genus. Only one group could be assigned with confidence to a named species (M. galopus). Our Mycena sequences clustered with other Mycena sequences detected in roots of ericoid mycorrhizal plant species collected throughout Europe, America, and Australia. An isolate of M. galopus promoted growth of V. corymbosum seedlings in vitro regardless of external carbon supply in the media. Seedlings inoculated with M. galopus grew as well as those inoculated with the ericoid mycorrhizal fungus Rhizoscyphus ericae. Surprisingly, this M. galopus isolate colonized Vaccinium roots and formed distinctive peg-like structures. Our results suggest that Mycena species might operate along a saprotroph-symbiotic continuum with a range of ericoid mycorrhizal plant species. We discuss our results in terms of fungal partner recruitment by Ericaceae plants.

  15. Transformation of Medicago truncatula via infiltration of seedlings or flowering plants with Agrobacterium

    DEFF Research Database (Denmark)

    Trieu, A.T.; Burleigh, S.H.; Kardailsky, I.V.

    2000-01-01

    Two rapid and simple in planta transformation methods have been developed for the model legume Medicago truncatula. The first approach is based on a method developed for transformation of Arabidopsis thaliana and involves infiltration of flowering plants with a suspension of Agrobacterium....... The second method involves infiltration of young seedlings with Agrobacterium. In both cases a proportion of the progeny of the infiltrated plants is transformed. The transformation frequency ranges from 4.7 to 76% for the flower infiltration method, and from 2.9 to 27.6% for the seedling infiltration method....... Both procedures resulted in a mixture of independent transformants and sibling transformants. The transformants were genetically stable, and analysis of the T-2 generation indicates that the transgenes are inherited in a Mendelian fashion. These transformation systems will increase the utility of M...

  16. Seedling stage strategies as a means of habitat specialization in herbaceous plants

    DEFF Research Database (Denmark)

    ten Brink, Dirk-Jan; Bruun, Hans Henrik

    2011-01-01

    The regeneration niche has been little investigated in studies of community assembly and plant distribution. We examined adaptive associations between seedling traits and habitat specialization. Two habitat contrasts were investigated across several evolutionary lineages of angiosperms: species...... specialized to forest vs. open habitats and to dry vs. wet habitats. We also tested whether effects of shade and drought vary independently or, alternatively, if shade may amplify effects on drought-stressed plants. Seedling response in terms of growth rate, height, slenderness, specific leaf area (SLA......) and degree of elongation (longest internode; petiole or leaf-sheath depending on species' morphology) to light and watering treatments was assessed. We used a factorial design involving three light regimes and two watering frequencies. The open-shaded habitat contrast and the dry-wet habitat contrast were...

  17. Sites of infection by pythium species in rice seedlings and effects of plant age and water depth on disease development.

    Science.gov (United States)

    Chun, S C; Schneider, R W

    1998-12-01

    ABSTRACT Seedling disease, caused primarily by several species of Pythium, is one of the major constraints to water-seeded rice production in Louisiana. The disease, also known as water-mold disease, seed rot, and seedling damping-off, causes stand reductions and growth abnormalities. In severe cases, fields must be replanted, which may result in delayed harvests and reduced yields. To develop more effective disease management tactics including biological control, this study was conducted primarily to determine sites of infection in seeds and seedlings; effect of plant age on susceptibility to P. arrhenomanes, P. myriotylum, and P. dissotocum; and minimum exposure times required for infection and seedling death. In addition, the effect of water depth on seedling disease was investigated. Infection rates of seed embryos were significantly higher than those of endosperms for all three Pythium spp. The development of roots from dry-seeded seedlings was significantly reduced by P. arrhenomanes and P. myriotylum at 5 days after planting compared with that of roots from noninoculated controls. Susceptibility of rice to all three species was sharply reduced within 2 to 6 days after planting, and seedlings were completely resistant at 8 days after planting. There was a steep reduction in emergence through the flood water, relative to the noninoculated control, following 2 to 3 days of exposure to inoculum of P. arrhenomanes and P. myriotylum. In contrast, P. dissotocum was much less virulent and required longer exposure times to cause irreversible seedling damage. Disease incidence was higher when seeds were planted into deeper water, implying that seedlings become resistant after they emerge through the flood water. These results suggest that disease control tactics including flood water management need to be employed for a very short period of time after planting. Also, given that the embryo is the primary site of infection and it is susceptible for only a few days, the

  18. Afforestation of Boreal Open Woodlands: Early Performance and Ecophysiology of Planted Black Spruce Seedlings

    OpenAIRE

    Tremblay, Pascal; Boucher, Jean-Francois; Tremblay, Marc; Lord, Daniel

    2013-01-01

    Open lichen woodlands (LWs) are degraded stands that lack the ability to regenerate naturally due to a succession of natural and/or anthropogenic disturbances. As they represent both interesting forest restoration and carbon sequestration opportunities, we tested disc scarification and planting of two sizes of containerized black spruce (Picea mariana Mill. (BSP)) seedlings for their afforestation. We compared treatment of unproductive LWs to reforestation of harvested, closed-crown black spr...

  19. Influence of nonuniform magnetic fields on orientation of plant seedlings in microgravity conditions

    Science.gov (United States)

    Nechitailo, G. S.; Mashinsky, A. L.; Kuznetsov, A. A.; Chikov, V. M.; Kuznetsov, O. A.

    2001-01-01

    Experiments on the spatial behavior of the flax ( Linum usitatissimum, L.) seedlings in a nonuniform magnetic field were conducted on the orbital space stations «Salutå and «Mirå. This field can displace sensory organelles (statoliths) inside receptor cells and such displacement should cause a physiological reaction of the plant - tropistic curvature. Experiments were conducted in the custom-built «Magnetogravistatå facility, where seeds were germinated and grown for 3-4 days in a magnetic field with the dynamic factor grad(H 2/2)≈ 10 7 Oe 2/cm, then fixed on orbit and returned to Earth for analysis. It was found, that 93% of the seedlings were oriented in the field consistently with curvature in response to displacement of statoliths along the field gradient by ponderomotive magnetic forces, while control seedlings grew in the direction of the initial orientation of the seed. This suggests, that gravity receptors of plants recognized magnetic forces on statoliths as gravity, and that gravity stimulus can be substituted for plants by a force of a different physical nature.

  20. Remnant Trees in Enrichment Planted Gaps in Quintana Roo, Mexico: Reasons for Retention and Effects on Seedlings

    Directory of Open Access Journals (Sweden)

    Angélica Navarro-Martínez

    2017-07-01

    Full Text Available Natural forest management in the tropics is often impeded by scarcity of advanced regeneration of commercial species. To supplement natural regeneration in a forest managed by a community in the Selva Maya of Mexico, nursery-grown Swietenia macrophylla seedlings were planted in multiple-tree felling gaps, known as bosquetes. Remnant trees are often left standing in gaps for cultural and economic reasons or due to their official protected status. We focus on these purposefully retained trees and their impacts on planted seedlings. Sampled bosquetes were 400–1800 m2, of which remnant trees covered a mean of 29%. Seedling height growth rates over the first 18 months after out-planting more than doubled with increased canopy openness from 0.09 m year−1 under medium cover to 0.22 m year−1 in full sun. Liana infestations and shoot tip damage were most frequent on seedlings in the open, but, contrary to our expectations, height growth rates were 0.14 m year−1 faster for liana-infested seedlings than non-infested and did not differ between damaged and undamaged seedlings. Apparently the more rapid height growth of well-illuminated seedlings more than compensated for the effects of lianas or shoot tip damage. Despite the abundance of remnant trees and their negative effects on seedling growth, enrichment planting in bosquetes has potential for community-based natural forest management in the tropics in supplementing natural regeneration of commercial species. One obvious recommendation is to leave fewer remnant trees, especially those of commercial species that are non-merchantable due to stem defects and trees retained for no apparent reason, which together constituted half of the remnant crown cover in the sampled bosquetes. Finally, given the rapid growth of lianas and understory palms in large canopy gaps, at least the most vigorous of the planted seedlings should be tended for at least two years.

  1. Environmental effects of nanosilver: impact on castor seed germination, seedling growth, and plant physiology.

    Science.gov (United States)

    Yasur, Jyothsna; Rani, Pathipati Usha

    2013-12-01

    Increasing use of nanoparticles in daily products is of great concern today, especially when their positive and negative impact on environment is not known. Hence, in current research, we have studied the impact of silver nanoparticle (AgNPs) and silver nitrate (AgNO3) application on seed germination, root, and shoot length of castor bean, Ricinus communis L. plant. Silver nanoparticles had no significant effects on seedling growth even at higher concentration of 4,000 mg L(-1), while the silver in bulk form as AgNO3 applied on the castor bean seeds inhibited the seed germination. Silver uptake in seedlings of the castor seeds on treatment with both the forms of silver was confirmed through atomic absorption spectroscopy studies. The silver nanoparticle and silver nitrate application to castor seeds also caused an enhanced enzymatic activity of ROS enzymes and phenolic content in castor seedlings. High-performance liquid chromatography analysis of individual phenols indicated enhanced content of parahydroxy benzoic acid. These kinds of studies are of great interest in order to unveil the movement and accumulation of nanoparticles in plant tissues for assessing future applications in the field or laboratory.

  2. Chemical evaluation of strawberry plants produced by tissue culturing of gamma irradiated seedlings

    International Nuclear Information System (INIS)

    Maraei, R.W.

    2007-01-01

    studies were conducted to evaluate the influence of gamma irradiation as a supplementary factor precedes tissue culture application on strawberry seedlings (c.v.Rosa Linda). the strawberry seedling were irradiated using 8 doses of co 60 gamma rays 50.75.100.125 ,150,250, 350 and 500 gray. tissue culture technique was applied on irradiated and unirradiated strawberry seedling. different characteristics of plantlets, plant and fruit of strawberry produced from the double treatment (irradiation followed by tissue culture) were studied as well as the early, total and exportable fruit yields. data indicated that, low radiation doses 50,75 and 100 gray increased all morphological and chemical characteristics of the plantlets, plant and fruit of strawberry, whereas radiation doses higher than 100 gray decreased them significantly. moreover 350 and gray were lethal doses. radiation dose 50 gray increased the survival percentage and the length of plantlets by 1.5% and 50% respectively more than the unirradiated treatment in all multiplication stages

  3. Plant growth regulators and ascorbic acid effects on physiological quality of wheat seedlings obtained from deteriorated seeds

    International Nuclear Information System (INIS)

    Moori, S.; Eisv, H.R.

    2017-01-01

    This study attempted to examine the effect of seed priming using plant growth regulators and vitamin C on the physiological traits of non-aged and aged seeds of wheat and their obtained seedlings. Accelerated aging (AA) method (40 degree C, RH=100% for 72h) was used for aging seeds. The seeds were pre-treated by gibberellin (GA), salicylic acid (SA), brassinosteroid (BR), and ascorbic acid (AS). Some seed traits such as germination and electric conductivity (EC) and seedling traits such as malondialdehyde (MDA) content, activity of some antioxidant enzymes, soluble protein content (SP), soluble sugar (SS), and proline were measured seven days after germination. The results showed that accelerated aging of seeds reduces the germination percentage and speed, increases soluble sugar, and reduces soluble protein, activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in the seedling. Pre-treatment of the aged seed by GA had the maximum positive impact on seed germination and seedling growth. Priming improved germination indices, quality of seedling, and seedling resistance against the oxidative stress caused by AA. It also improved cell membrane integrity and thus reduced seeds’ EC. Priming increased the activity of CAT, POD and SOD enzymes in both aged and non-aged seeds. When the deteriorated seeds were primed, proline and SS contents of the seedling increased significantly, but SP and MDA decreased. In general, pre-treatment of the non-aged and aged seeds by gibberellin improved the physiological quality of the seed and seedling. (author)

  4. Phytotoxic Activity of Ocimum tenuiflorum Extracts on Germination and Seedling Growth of Different Plant Species

    Directory of Open Access Journals (Sweden)

    A. K. M. Mominul Islam

    2014-01-01

    Full Text Available Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum, lettuce (Lactuca sativa, alfalfa (Medicago sativa, Italian ryegrass (Lolium multiflorum, barnyard grass (Echinochloa crus-galli, and timothy (Phleum pratense at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP, germination index (GI, germination energy (GE, speed of emergence (SE, seedling vigour index (SVI, and coefficient of the rate of germination (CRG of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50 and mean germination time (MGT were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.

  5. Accelerating Planted Green Ash Establishment on an Abandoned Soybean Field

    Science.gov (United States)

    John W. Groninger; Didier A. Babassana

    2002-01-01

    Planted green ash seedlings exhibit high survival rates on most bottomland sites that have recently come out of row crop production, making this species a popular choice for afforestation. Sub-optimal growth of planted hardwood tree species, including green ash, often delays the realization of many of the economic and environmental benefits that are used to justify the...

  6. Seventh workshop on seedling physiology and growth problems in oak plantings (abstracts); 1998 September 27-29; South Lake Tahoe, CA.

    Science.gov (United States)

    D.D. McCreary; J.G. Isebrands

    1999-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 17 abstracts.

  7. Use of Excel ion exchange equilibrium solver with WinGEMS to model and predict NPE distribution in the Mead/Westvaco Evandale, TX, hardwood bleach plant

    Science.gov (United States)

    Christopher Litvay; Alan Rudie; Peter Hart

    2003-01-01

    An Excel spreadsheet developed to solve the ion-exchange equilibrium in wood pulps has been linked by dynamic data exchange to WinGEMS and used to model the non-process elements in the hardwood bleach plant of the Mead/Westvaco Evandale mill. Pulp and filtrate samples were collected from the diffusion washers and final wash press of the bleach plant. A WinGEMS model of...

  8. EFFECT OF PLANTING MEDIA ON THE GROWTH OF Shorea pinanga Scheff. SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Diana Prameswari

    2004-11-01

    Full Text Available Shoreapinanga Scheff.   is a major tropical plant species which has an important  economic  value not  only for timber,  but also as illipe nut  (called tengkawang  in local  name production.   This species   is suggested   for  land  rehabilitation    and  forest  conservation.    In rehabilitation   action, S. pi11a11ga is usually   planted   on the poor  and degraded  area.   Application   of  chemical  fertilizer and compost  is used to increase  the survival  and growth  of  the  seedlings.  Excessive chemical fertilizer  input  to soil, however,  may cause  negative  effect on  soil,  plant  and  environment. Conversely,  compost  may improve soil porosity, soil aggregate,  water absorption   and soil fertility. The objective  of  the study  was  to examine  effect  of  planting  media  on growth  of  S. pinanga  seedlings. Complete  randomized  design has been arranged with 5 treatments,  e.g. soil mixed with husk  (at the proportion   of  1:1, soil mixed with acacia compost  (1:1,   soil mixed with charcoal of  rice husk (1:1   and soil mixed with humic acid (1:1.    Another  treatment  was  soil alone  used as control.   The  result showed that  growth  of  both  stem  height   and  diameter,  and  index  of seedling  quality  were affected  significantly   by planting  media.    The mixture  of  soil and  acacia compost  (1 :1  was the best  planting media for the growth  of S. pinanga seedlings,  which resulted in the growth  of height  (24.19   cm and stem diameter  (0.246 cm.  Meanwhile, soil mixed with rice husk charcoal (1:1  gave the best result to the index of  seedling quality (ISQ = 1.34   and total dry weight (TOW=   15.93  g.

  9. Effect of Salinity on Germination and Seedling Growth of Four Medicinal Plants

    Directory of Open Access Journals (Sweden)

    A Dadkhah

    2012-07-01

    Full Text Available This experiment was conducted in germinator in order to study the effects of water potential on seed germination, rate of germination and seedlings growth of four medicinal plants (Coriandrum sativum, Plantago psyllium, Discorinia sophia and Portulaca oleracea. Four water potential inclouding distilled water as control (0, -0.37, -0.59 and –0.81 Mpa which made by different salts (NaCl, CaCl2 and NaCl+CaCl2 in 5 to 1 molar ratio. The experiment was carried out based on completly randomized design with six replications. Results showed that the effects of water potential, type of salt on germination percentage, rate of germination, root and shoot length were significant. With decreasing water potential, germination percentage and rate of germination declined but the response of plant were differ. Germination of Portulaca oleracea was not affected by decreasing water potential where as other significantly decreased. The effect of salt composition was significant on rate and percentage germination. The percentage of germination at lower water potential (–0.37 MPa which made by NaCl + CaCl2 significantly was higher than the same water potential made by only NaCl and CaCl2. Although, percentage and rate germination of Portulaca oleracea were not affected by different water potential, seedling growth of Portulaca oleracea significantly decreased.

  10. Influence of irrigation method and container type on Northern red oak seedling growth and media electrical conductivity

    Science.gov (United States)

    Anthony S. Davis; Douglass F. Jacobs; Ronald P. Overton; R. Kasten Dumroese

    2008-01-01

    Container production of hardwood seedlings has not been extensively practiced. Efficient nursery production of hardwood seedlings in containers can be limited by formation of a broad foliar canopy, which limits irrigation uniformity. This study was established to investigate suitability of subirrigation, a method of irrigating seedlings from the container base that...

  11. Morphology and anatomy of the seedling and the tirodendro of Calophyllum brasiliense Cambess. (Clusiaceae

    Directory of Open Access Journals (Sweden)

    Valquíria Aparecida Mendes de Jesus

    2014-10-01

    Full Text Available Calophyllum brasiliense Cambess. is a tree species that is presented as an alternative to replace endangered species of hardwood. The morphology and anatomy of the seedling of this species is the object of the present study. Seedlings at different stages of development were obtained in greenhouse and analyzed fresh and fixed in FAA (Formalin-Acetic-Alcohol 50. The anatomical analysis was done by the freehand and microtome sections, according to standard techniques in plant anatomy. The seedling and/or tirodendro is cryptocotylar and hypogeal, has cataphylls, and presents eophylls and metaphylls simple with venation pinnate craspedodromous simple. The root is polyarch, the hypocotyl is very short, the cotyledons have an oily and starchy reserve, the epicotyl has stem structure, and eophylls and metaphylls are dorsiventral. The seedling may be classified in the Horsfieldia type/subtype.

  12. Mixed-power scaling of whole-plant respiration from seedlings to giant trees.

    Science.gov (United States)

    Mori, Shigeta; Yamaji, Keiko; Ishida, Atsushi; Prokushkin, Stanislav G; Masyagina, Oxana V; Hagihara, Akio; Hoque, A T M Rafiqul; Suwa, Rempei; Osawa, Akira; Nishizono, Tomohiro; Ueda, Tatsushiro; Kinjo, Masaru; Miyagi, Tsuyoshi; Kajimoto, Takuya; Koike, Takayoshi; Matsuura, Yojiro; Toma, Takeshi; Zyryanova, Olga A; Abaimov, Anatoly P; Awaya, Yoshio; Araki, Masatake G; Kawasaki, Tatsuro; Chiba, Yukihiro; Umari, Marjnah

    2010-01-26

    The scaling of respiratory metabolism with body mass is one of the most pervasive phenomena in biology. Using a single allometric equation to characterize empirical scaling relationships and to evaluate alternative hypotheses about mechanisms has been controversial. We developed a method to directly measure respiration of 271 whole plants, spanning nine orders of magnitude in body mass, from small seedlings to large trees, and from tropical to boreal ecosystems. Our measurements include the roots, which have often been ignored. Rather than a single power-law relationship, our data are fit by a biphasic, mixed-power function. The allometric exponent varies continuously from 1 in the smallest plants to 3/4 in larger saplings and trees. Therefore, our findings support the recent findings of Reich et al. [Reich PB, Tjoelker MG, Machado JL, Oleksyn J (2006) Universal scaling of respiratory metabolism, size, and nitrogen in plants. Nature 439:457-461] and West, Brown, and Enquist [West GB, Brown JH, Enquist BJ (1997) A general model for the origin of allometric scaling laws in biology. Science 276:122 -126.]. The transition from linear to 3/4-power scaling may indicate fundamental physical and physiological constraints on the allocation of plant biomass between photosynthetic and nonphotosynthetic organs over the course of ontogenetic plant growth.

  13. Performance of Oak Seedlings Grown under Different Oust® XP Regimes

    Directory of Open Access Journals (Sweden)

    Andrew Self

    2014-06-01

    Full Text Available Herbaceous weed control (HWC is prescribed for growing season control of vegetative competition in hardwood afforestation attempts on former agricultural areas. Without HWC, planted seedlings often exhibit poor growth and survival. While currently employed HWC methods are proven, there is a substantial void in research comparing HWC treatments spanning multiple years. A total of 4,320 bare-root seedlings of three oak species were planted on three Mississippi sites. All sites were of comparable soils and received above average precipitation for the majority of the three-year study. Eight combinations of HWC and mechanical site preparation were utilized at each site, with 480 seedlings planted in each of the nine blocks, and a total of 1,440 seedlings per species planted across all sites. Treatments were installed on 3.1 m centers, with mechanical treatments as follows: control, subsoiling, bedding, and combination plowing. HWC treatments included one and two-year applications of Oust® XP. Treatments were applied over seedlings post-planting in 1.5 m bands, at a rate of 140.1 g product/hectare. Excepting one species, HWC dependent height or groundline diameter differences were not detected among mechanical treatments, species, HWC regime, or combinations thereof. No survival differences were observed among site preparation treatments or species. However, analysis detected a growing season/HWC treatment interaction for seedling survival.

  14. Loblolly pine seedling growth after inoculation with plant growth-promoting rhizobacteria and ozone exposure

    Energy Technology Data Exchange (ETDEWEB)

    Estes, B.L.; Enebak, S.A.; Chappelka, A.H. [Auburn Univ., Auburn, AL (United States). School of Forestry and Wildlife Sciences

    2004-07-01

    The conifer tree species with the greatest economic importance in south eastern United States plantations is Loblolly pine. Plantations require intensive fertilization, pesticide application, and irrigation. In these cases growth-promoting rhizobacteria are useful in pest control. While it was once thought that ozone in the troposphere was limited to urban areas, it is now known that it is transported far from its place of origin. Ozone is known to impact plant growth negatively. There have been no previous studies on whether growth-promoting rhizobacteria can decrease the negative effects of ozone. In this study seedlings of Loblolly pine were inoculated with either Bacillus subtilis (Ehrenberg) Cohn or Paenibacillus macerans (Schardinger) Ash. These were exposed to controlled amounts of ozone for 8-12 weeks. All plants showed decreased biomass and increased foliar damage compared to plants that were not exposed to ozone. B. subtilis inoculated plants showed less foliar damage than un-inoculated ones and root dimensions were increased. The use of growth-promoting rhizobacteria is not ready for large-scale commercial application in forestry, but this demonstration of the possible beneficial effects on ozone exposure warrants further investigation. 44 refs., 3 tabs., 2 figs.

  15. Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants

    DEFF Research Database (Denmark)

    Merrild, Marie Porret; Ambus, Per; Rosendahl, Søren

    2013-01-01

    ) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of 32P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact...... or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre‐established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed...

  16. EFFECT OF PLANT EXTRACTS AND GROWTH SUBSTRATES ON CONTROLLING DAMPING-OFF IN PINUS TECUNUMANII SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Maria Alejandra Fajardo-Mejía

    2016-09-01

    Full Text Available Damping-off is considered one of the most limiting phytosanitary problems in conifer seedling production because it may cause massive damage or total plant death in short time periods. This pathology is caused by a complex of microorganisms, the most common of which are Fusarium spp. and Rhizoctonia spp. This study evaluated the effect of growth substrates and plant extracts at different concentrations on germination and incidence of disease in Pinus tecunumanii plants. The plants were inoculated with the damping-off pathogen Fusarium oxysporum and treatments were applied in a completely randomized design with a factorial arrangement of 4x2x3. This corresponded to four substrates (pine bark, rice hull, coconut husk and sandy soil (4:1; two plant extracts (Matricaria chamomilla and Datura stramonium, andthree concentrations of each extract (Control concentration: 0%, Concentration 1: 50 % and Concentration 2: Undiluted. Each treatment had three repetitions, with 25 plants per repetition. The growth substrates affected germination; the most effective of these were sandy soil (4:1 and pine bark, with 90% and 92% germination at day 20, respectively. No significant difference was observed between the germination obtained with these substrates and that obtained with coconut husk after day 19. Meanwhile, all of the extracts had a significant effect on controlling the disease when they were combined with the substrates, with the exception of coconut husk. With this last substrate the incidence of disease was lower than 4% without the application of plant extracts; this indicates that coconut husk discourages the development of the disease on its own.

  17. Effect of plant growth promoting rhizobia on seed germination and seedling traits in Acacia senegal

    Directory of Open Access Journals (Sweden)

    S.K. Singh

    2011-11-01

    Full Text Available Among arid zone tree species, Acacia senegal and Prosopis cineraria are the most important dryland resources of Western Rajasthan desert ecosystem. Due to ecological, biological and molecular similarities, they are often studied together. The climatic conditions in this region restrict the build-up of soil organic matter and soils are generally deficient in nitrogen. Studies were carried out to isolate and molecularly characterize the diverse group of plant growth promoting rhizobacteria from root nodules of native A. senegal and P. cineraria and their effect on seed germination and seedling traits in two genotypes of A. senegal. The direct sequencing of 16S rDNA region resulted in molecular identification of plant growth promoting rhizobacteria as Bacillus licheniformis, Sinorhizobium saheli isolated from root nodules of A. senegal and S. kostiense and S. saheli isolated from root nodules of P. cineraria. The partial sequences of 16S rDNA were assigned Gen accession numbers HQ738496, HQ738499, HQ738506 and HQ738508. Scarification treatment with sulphuric acid (98% for 15 minutes was able to break the exogenous seed dormancy and enhanced germination percentage in control treatment to 90% and 92.5% in A. senegal in genotypes CAZRI 113AS and CAZRI 35AS, respectively. The treatments with Bacillus licheniformis or S. kostiense, either inoculated individually or as coinoculants, had positive effect on phenotypic traits of germination. Two A. senegal genotypes exhibited significant differences with regard to all the phenotypic traits. On the other hand, treatments with S. saheli isolated from either A. senegal or P. cineraria had negative effects on germination and related phenotypic traits. Values of the coeffivient of determination (R2 over 80% for root length versus shoot length, root/shoot ratio and seedling weight respectively validate that the observed attributes are inter-dependable and linear progression trend can be predicted.

  18. Plant Killing by Mutualistic Ants Increases the Density of Host Species Seedlings in the Dry Forest of Costa Rica

    OpenAIRE

    Amador-Vargas, Sabrina

    2012-01-01

    Some species of plant-mutualistic ants kill the vegetation growing in the vicinities of their host plant, creating an area of bare ground (clearing). The reduced competition in the clearing may facilitate the establishment of host species sprouts (clones and seedlings), which in turn benefits the ants with additional food and shelter (“sprout-establishment hypothesis”). To test this hypothesis, the density and origin of Acacia collinsii sprouts growing inside clearings and in the vicinities o...

  19. Phenotypic plasticity of fine root growth increases plant productivity in pine seedlings

    Directory of Open Access Journals (Sweden)

    Grissom James E

    2004-09-01

    Full Text Available Abstract Background The plastic response of fine roots to a changing environment is suggested to affect the growth and form of a plant. Here we show that the plasticity of fine root growth may increase plant productivity based on an experiment using young seedlings (14-week old of loblolly pine. We use two contrasting pine ecotypes, "mesic" and "xeric", to investigate the adaptive significance of such a plastic response. Results The partitioning of biomass to fine roots is observed to reduce with increased nutrient availability. For the "mesic" ecotype, increased stem biomass as a consequence of more nutrients may be primarily due to reduced fine-root biomass partitioning. For the "xeric" ecotype, the favorable influence of the plasticity of fine root growth on stem growth results from increased allocation of biomass to foliage and decreased allocation to fine roots. An evolutionary genetic analysis indicates that the plasticity of fine root growth is inducible, whereas the plasticity of foliage is constitutive. Conclusions Results promise to enhance a fundamental understanding of evolutionary changes of tree architecture under domestication and to design sound silvicultural and breeding measures for improving plant productivity.

  20. Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings.

    Science.gov (United States)

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-10-01

    One of the proposed mechanisms through which plant growth-promoting rhizobacteria (PGPR) enhance plant growth is the production of plant growth regulators, especially cytokinin. However, little information is available regarding cytokinin-producing PGPR inoculation on growth and water stress consistence of forest container seedlings under drought condition. This study determined the effects of Bacillus subtilis on hormone concentration, drought resistance, and plant growth under water-stressed conditions. Although no significant difference was observed under well-watered conditions, leaves of inoculated Platycladus orientalis (oriental thuja) seedlings under drought stress had higher relative water content and leaf water potential compared with those of noninoculated ones. Regardless of water supply levels, the root exudates, namely sugars, amino acids and organic acids, significantly increased because of B. subtilis inoculation. Water stress reduced shoot cytokinins by 39.14 %. However, inoculation decreased this deficit to only 10.22 %. The elevated levels of cytokinins in P. orientalis shoot were associated with higher concentration of abscisic acid (ABA). Stomatal conductance was significantly increased by B. subtilis inoculation in well-watered seedlings. However, the promoting effect of cytokinins on stomatal conductance was hampered, possibly by the combined action of elevated cytokinins and ABA. B. subtilis inoculation increased the shoot dry weight of well-watered and drought seedlings by 34.85 and 19.23 %, as well as the root by 15.445 and 13.99 %, respectively. Consequently, the root/shoot ratio significantly decreased, indicative of the greater benefits of PGPR on shoot growth than root. Thus, inoculation of cytokinin-producing PGPR in container seedlings can alleviate the drought stress and interfere with the suppression of shoot growth, showing a real potential to perform as a drought stress inhibitor in arid environments.

  1. A role for arabinogalactan-proteins in plant cell expansion: evidence from studies on the interaction of ß-glucosyl Yariv reagent with seedlings of Arabidopsis thaliana

    DEFF Research Database (Denmark)

    Willats, William George Tycho; Knox, J.P.

    1996-01-01

    Seedlings of Arabidopsis thaliana were germinated and grown in medium containing ß-glucosyl Yariv reagent (ßGlcY), a synthetic phenyl glycoside that interacts specifically with arabinogalactan-proteins (AGPs), a class of plant cell surface proteoglycans. The effect of ßGlcY on the seedlings...

  2. Century-scale Variations in Plant and Soil Nitrogen Pools and Isotopic Composition in Northern Hardwood Forests

    Science.gov (United States)

    Goodale, C. L.; Fuss, C. B.; Lang, A.; Ollinger, S. V.; Ouimette, A.; Vadeboncoeur, M. A.; Zhou, Z.; Lovett, G. M.

    2017-12-01

    The mineral soil may act as both a source and a sink of nitrogen to plants over decadal to centennial timescales. However, the enormous size and spatial heterogeneity of mineral soil N regularly impede study of its role over the course of forest succession. Here, we measured tree and soil stocks of C, N and 15N to 50 cm depth in and near Hubbard Brook, New Hampshire, across eight forest stands of varying time since harvest (two stands each of 20, 40, and 100 years post-harvest, and old-growth forest). Measurements show that tree biomass and N stocks increased with stand age to an average of 145 t C/ha and 556 kg N/ha in old-growth forests, as cumulative net growth and N increment rates decreased from young (20 and 40-year old) to mature (100-year) to old-growth stands. Plant %N varied more by site than species, while plant 15N varied more by tree species than by site. Of the most common species, Acer saccharum (sugar maple) had consistently lighter 15N in all tissues (bark, leaf, wood) than Betula alleghaniensis (yellow birch). Soil organic matter stocks are very large, averaging 154 t C/ha and 8.1 tN/ha to 50 cm depth. Neither C nor N stock varied regularly with stand age, but old-growth stands had lower C:N ratios and higher 15N values than the successional stands. Ongoing analysis will predict the effects of harvest, regrowth, and N inputs and losses on expected and observed 15N changes over succession. These observations support the great capacity of the mineral soil to store and potentially supply N to northern hardwood forests.

  3. Utilizing NASA EOS to Assist in Determining Suitable Planting Locations for Bottomland Hardwood Trees in St. Bernard Parish, Louisiana

    Science.gov (United States)

    Reahard, R. R.; Arguelles, M.; Ewing, M.; Kelly, C.; Strong, E.

    2012-12-01

    St. Bernard Parish, located in southeast Louisiana, is rapidly losing coastal forests and wetlands due to a variety of natural and anthropogenic disturbances (e.g. subsidence, saltwater intrusion, low sedimentation, nutrient deficiency, herbivory, canal dredging, levee construction, spread of invasive species, etc.). After Hurricane Katrina severely impacted the area in 2005, multiple Non-Governmental Organizations (NGOs) have focused not only on rebuilding destroyed dwellings, but on rebuilding the ecosystems that once protected the citizens of St. Bernard Parish. Volunteer groups, NGOs, and government entities often work separately and independently of each other and use different sets of information to choose the best planting sites for restoring coastal forests. Using NASA Earth Observing Systems (EOS), Natural Resource Conservation Service (NRCS) soil surveys, and ancillary road and canal data in conjunction with ground truthing, the team created maps of optimal planting sites for several species of bottomland hardwood trees to aid in unifying these organizations, who share a common goal, under one plan. The methodology for this project created a comprehensive Geographic Information System (GIS) to help identify suitable planting sites in St. Bernard Parish. This included supplementing existing elevation data using Digital Elevation Models derived from LIDAR data, and determining existing land cover in the study area from classified Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery. Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) data from a single low-altitude swath was used to assess the health of vegetation over an area near the Mississippi River Gulf Outlet Canal (MRGO) and Bayou La Loutre. Historic extent of coastal forests was also mapped using aerial photos collected between 1952 and 1956. The final products demonstrated yet another application of NASA EOS in the rebuilding and monitoring of coastal ecosystems in

  4. Damages and causes of death in plantations with containerised seedlings of Scots pine and Norway spruce in the central of Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Naumburg, Jan

    2000-07-01

    In 1972, 94 forest areas were planted with containerised seedlings, 83 with Scots pine (Pinus sylvestris L.) and 11 with Norway spruce (Picea abies (L.) Karst.), in the central of Sweden. In the first season after planting, 99% of the Scots pine and 98% of the Norway spruce seedlings survived. Three seasons after plantation, 67% of Scots pine and 62% of Norway spruce were alive. The most common type of known damages causing mortality were mammals and insects. Vegetation was registered as the cause of mortality at some occasions in Scots pine plantations, whereas vegetation never was considered as the cause of death in Norway spruce plantations. The average size of the scarification patches were 0.25 m{sup 2} and 0.4 m{sup 2} in Scots pine and Norway spruce respectively. In Scots pine plantations there were 1600 planted seedlings ha{sup -1} and in Norway spruce there were 1550 ha{sup -1}. After the third growing season, the numbers of main crop plants, including naturally regenerated hardwood and softwood plants, were 1500 ha{sup -1} for Scots pine and 1350 ha{sup -1} for Norway spruce. The studied plantings had been approved if the recommended number of seedlings had been planted. As there always is some mortality among planted seedlings, in the present study 35-40%, this phenomenon has to be taken into consideration when dimensioning the number of seedlings which are to be planted.

  5. The role of plant water relations in achieving and maintaining the target seedling

    Science.gov (United States)

    John G. Mexal; Nabil Khadduri

    2011-01-01

    Water management is one of the most important factors in achieving the target seedling. Water is required for cell growth, nutrient transport, cooling through transpiration, and in small amounts for the photosynthetic reaction. Furthermore, judicious use of limiting water availability during the hardening phase can induce budset and increase seedling cold hardiness....

  6. EFFECT OF DROUGHT STRESS INDUCED BY MANNITOL ON PHYSIOLOGICAL PARAMETERS OF MAIZE (ZEA MAYS L. SEEDLINGS AND PLANTS

    Directory of Open Access Journals (Sweden)

    Katarzyna Możdżeń

    2015-02-01

    Full Text Available Plants are exposed to various stress factors which might lead to structural damage and physiological function abnormalities. Drought is one of the environmental stress factors that reduce the productivity of plants. The aim of our study was to determine the influence of drought stress induced by mannitol (-0.5 and -1.5MPa on selected physiological processes in Z. mays L. In the first stage we studied the effect of mannitol on the germination. In the second stage the effect of mannitol on the growth of plants germinated on distilled water and watered with mannitol in growth phase were measured. Mannitol, which decreased the water content in a concentration-dependent manner, had an inhibitory effect on germination and growth of seedlings and adult plants. Electrolyte leakage of cell membranes of the Z. mays seedlings showed high disturbances in the functioning of the membrane structures in the osmotic drought conditions. Similar results were obtained for maize roots, shoots and leaves in both treatment studies. Chlorophyll content showed only significant differences in plants from treated during the growth phase. Drought stress caused a decrease in chlorophyll content by almost a half compared to the control plants. Measurements of chlorophyll fluorescence of plant leaves from the second stage of experiments showed changes in fluorescence activity parameters Fv/Fm, NPQ, Rfd, qP, ect.; gas exchange measurements also showed changes in activity in each of the two phases.

  7. Substrates with green manure compost and leaf application of biofertilizer on seedlings of yellow passion fruit plants

    Directory of Open Access Journals (Sweden)

    Cristiane Muniz Barbosa Barros

    2013-12-01

    Full Text Available Substrates and fertilization are fundamental for seedling production, which well nourished can produce earlier and are more resistant to stresses. Animal manures are often used in non-industrialized substrates with good results, but their costs are increasing. Other residues may be used for plant nutrition, in substrates or in leaf fertilization. The aim of this work was to evaluate substrates prepared with green manure composts and the leaf application of biofertilizer on the formation of yellow passion fruit seedlings. A greenhouse experiment was conducted between December 2009 and February 2010, with a split-plot random block design. Plots received or not leaf application of supermagro biofertilizer. Subplots consisted of different substrates: soil; soil + cattle manure; soil + cattle manure composted with black oats straw; soil + cattle manure composted with ryegrass straw; soil + cattle manure composted with turnip straw; and soil + cattle manure composted with vetch straw. There were three dates of leaf fertilization: 10, 25 and 40 days after emergence (DAE. At 50 DAE plants were collected for evaluation of growth and accumulation of biomass and nutrients: N, P, K, Ca, Mg, Cu, Mn and Zn. Data were submitted to analysis of variance and means compared by Tukey test. The substrate soil + cattle manure promoted higher stem diameter, plant height, leaf area, root length and volume and nutrient accumulation. Among substrates with green manure composts, those prepared with black oats and turnip straw outranked the others. The use of leaf biofertilizer showed diverse results on seedling formation, being beneficial when combined to substrates with black oats composted straw, and prejudicial when combined to soil + cattle manure and soil + turnip composted straw substrates. The accumulation of nutrients by the seedlings occurred in the following order: K>Ca>N>Mg>P>Zn>Cu=Mn.

  8. Arabidopsis seedling flood-inoculation technique: a rapid and reliable assay for studying plant-bacterial interactions

    Directory of Open Access Journals (Sweden)

    Uppalapati Srinivasa R

    2011-10-01

    Full Text Available Abstract Background The Arabidopsis thaliana-Pseudomonas syringae model pathosystem is one of the most widely used systems to understand the mechanisms of microbial pathogenesis and plant innate immunity. Several inoculation methods have been used to study plant-pathogen interactions in this model system. However, none of the methods reported to date are similar to those occurring in nature and amicable to large-scale mutant screens. Results In this study, we developed a rapid and reliable seedling flood-inoculation method based on young Arabidopsis seedlings grown on MS medium. This method has several advantages over conventional soil-grown plant inoculation assays, including a shorter growth and incubation period, ease of inoculation and handling, uniform infection and disease development, requires less growth chamber space and is suitable for high-throughput screens. In this study we demonstrated the efficacy of the Arabidopsis seedling assay to study 1 the virulence factors of P. syringae pv. tomato DC3000, including type III protein secretion system (TTSS and phytotoxin coronatine (COR; 2 the effector-triggered immunity; and 3 Arabidopsis mutants affected in salicylic acid (SA- and pathogen-associated molecular pattern (PAMPs-mediated pathways. Furthermore, we applied this technique to study nonhost resistance (NHR responses in Arabidopsis using nonhost pathogens, such as P. syringae pv. tabaci, pv. glycinea and pv. tomato T1, and confirmed the functional role of FLAGELLIN-SENSING 2 (FLS2 in NHR. Conclusions The Arabidopsis seedling flood-inoculation assay provides a rapid, efficient and economical method for studying Arabidopsis-Pseudomonas interactions with minimal growth chamber space and time. This assay could also provide an excellent system for investigating the virulence mechanisms of P. syringae. Using this method, we demonstrated that FLS2 plays a critical role in conferring NHR against nonhost pathovars of P. syringae, but not to

  9. Effects of chronic exposure of seeds and seeds and seedlings of Arabidopsis Thaliana by low doses of γ-radiation on plant growth and development

    International Nuclear Information System (INIS)

    Litvinov, S.V.

    2013-01-01

    Article presents the results of research on the effect of chronic γ-irradiation in small doses on A. Thaliana seedlings and seeds growth and development. Exposure rate for the seeds was 0,45 mGy/h (total absorbed dose 30 cSv) and 0,18 mGy/h for seedlings (total absorbed dose 3 cSv). Statistically significant differences in the germination capacity, in the time of primary leaf rosette formation, in the hypocotyl length were revealed between irradiated and control seedlings. Plants from irradiated seeds differed by the higher growth rate of stem, they flowered and fruited earlier, but they also characterized on average shorter vegetative cycle in comparison with control plants. In our experiments it is shown significant impact of chronic low doses of γ-irradiation of seeds and seedlings on the ontogeny in A. Thaliana and on the parameters that reflect the growth and development of the irradiated plants

  10. Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.

    Science.gov (United States)

    Dutta, Bhabesh; Gitaitis, Ronald; Smith, Samuel; Langston, David

    2014-01-01

    The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea) to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean) and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6) colony forming units (CFUs)/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion). Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO) assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating), respectively and they were not significantly different (P = 0.67). The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating) and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03). None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be colonized by

  11. Interactions of seedborne bacterial pathogens with host and non-host plants in relation to seed infestation and seedling transmission.

    Directory of Open Access Journals (Sweden)

    Bhabesh Dutta

    Full Text Available The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6 colony forming units (CFUs/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion. Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating, respectively and they were not significantly different (P = 0.67. The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03. None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be

  12. Adaptive transgenerational plasticity in an annual plant: grandparental and parental drought stress enhance performance of seedlings in dry soil.

    Science.gov (United States)

    Herman, Jacob J; Sultan, Sonia E; Horgan-Kobelski, Tim; Riggs, Charlotte

    2012-07-01

    Stressful parental (usually maternal) environments can dramatically influence expression of traits in offspring, in some cases resulting in phenotypes that are adaptive to the inducing stress. The ecological and evolutionary impact of such transgenerational plasticity depends on both its persistence across generations and its adaptive value. Few studies have examined both aspects of transgenerational plasticity within a given system. Here we report the results of a growth-chamber study of adaptive transgenerational plasticity across two generations, using the widespread annual plant Polygonum persicaria as a naturally evolved model system. We grew five inbred Polygonum genetic lines in controlled dry vs. moist soil environments for two generations in a fully factorial design, producing replicate individuals of each genetic line with all permutations of grandparental and parental environment. We then measured the effects of these two-generational stress histories on traits critical for functioning in dry soil, in a third (grandchild) generation of seedling offspring raised in the dry treatment. Both grandparental and parental moisture environment significantly influenced seedling development: seedlings of drought-stressed grandparents or parents produced longer root systems that extended deeper and faster into dry soil compared with seedlings of the same genetic lines whose grandparents and/or parents had been amply watered. Offspring of stressed individuals also grew to a greater biomass than offspring of nonstressed parents and grandparents. Importantly, the effects of drought were cumulative over the course of two generations: when both grandparents and parents were drought-stressed, offspring had the greatest provisioning, germinated earliest, and developed into the largest seedlings with the most extensive root systems. Along with these functionally appropriate developmental effects, seedlings produced after two previous drought-stressed generations had

  13. Identification of Sweet Sorghum accessions with seedling cold tolerance using both lab cold germination test and field early Spring planting evaluation

    Science.gov (United States)

    Cultivars with quick seedling emergence and stand establishment at early spring cold conditions may be planted early in the same region with an extended period of plant growth and can potentially increase either grain yield, stem sugar yield, or biomass production of sorghum. Planting cultivars with...

  14. Effect of Nano-ZnO Particle Suspension on Growth of Mung (Vigna radiata and Gram (Cicer arietinum Seedlings Using Plant Agar Method

    Directory of Open Access Journals (Sweden)

    Pramod Mahajan

    2011-01-01

    Full Text Available The present study demonstrates an effect of nano-ZnO particles on the growth of plant seedlings of mung (Vigna radiate and gram (Cicer arietinum. The study was carried out in plant agar media to prevent precipitation of water-insoluble nanoparticles in the test units. Various concentrations of nano-ZnO particles in suspension form were introduced to the agar media, and their effect on the root and shoot growth of the seedlings was examined. The main experimental approach, using correlative light and scanning electron microscopy provided evidence of adsorption of nanoparticles on the root surface. Absorption of nanoparticles by seedlings root was also detected by inductive coupled plasma/atomic emission spectroscopy (ICP-AES. It was found that at certain optimum concentration, the seedlings displayed good growth over control, and beyond that, retardation in growth was observed.

  15. Negative and positive interactions among plants: effects of competitors and litter on seedling emergence and growth of forest and grassland species.

    Science.gov (United States)

    Loydi, A; Donath, T W; Otte, A; Eckstein, R L

    2015-05-01

    Living plant neighbours, but also their dead aboveground remains (i.e. litter), may individually exert negative or positive effects on plant recruitment. Although living plants and litter co-occur in most ecosystems, few studies have addressed their combined effects, and conclusions are ambivalent. Therefore, we examined the response in terms of seedling emergence and growth of herbaceous grassland and forest species to different litter types and amounts and the presence of competitors. We conducted a pot experiment testing the effects of litter type (grass, oak), litter amount (low, medium, high) and interspecific competition (presence or absence of four Festuca arundinacea individuals) on seedling emergence and biomass of four congeneric pairs of hemicryptophytes from two habitat types (woodland, grassland). Interactions between litter and competition were weak. Litter presence increased competitor biomass. It also had positive effects on seedling emergence at low litter amounts and negative effects at high litter amounts, while competition had no effect on seedling emergence. Seedling biomass was negatively affected by the presence of competitors, and this effect was stronger in combination with high amounts of litter. Litter affected seedling emergence while competition determined the biomass of the emerged individuals, both affecting early stages of seedling recruitment. High litter accumulation also reduced seedling biomass, but this effect seemed to be additive to competitor effects. This suggests that live and dead plant mass can affect species recruitment in natural systems, but the mechanisms by which they operate and their timing differ. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  16. Degradation of seed mucilage by soil microflora promotes early seedling growth of a desert sand dune plant.

    Science.gov (United States)

    Yang, Xuejun; Baskin, Carol C; Baskin, Jerry M; Zhang, Wenhao; Huang, Zhenying

    2012-05-01

    In contrast to the extensive understanding of seed mucilage biosynthesis, much less is known about how mucilage is biodegraded and what role it plays in the soil where seeds germinate. We studied seed mucilage biodegradation by a natural microbial community. High-performance anion-exchange chromatography (HPAEC) was used to determine monosaccharide composition in achene mucilage of Artemisia sphaerocephala. Mucilage degradation by the soil microbial community from natural habitats was examined by monosaccharide utilization tests using Biolog plates, chemical assays and phospholipid fatty acid (PLFA) analysis. Glucose (29.4%), mannose (20.3%) and arabinose (19.5%) were found to be the main components of achene mucilage. The mucilage was biodegraded to CO(2) and soluble sugars, and an increase in soil microbial biomass was observed during biodegradation. Fluorescence microscopy showed the presence of mucilage (or its derivatives) in seedling tissues after growth with fluorescein isothiocyanate (FITC)-labelled mucilage. The biodegradation also promoted early seedling growth in barren sand dunes, which was associated with a large soil microbial community that supplies substances promoting seedling establishment. We conclude that biodegradation of seed mucilage can play an ecologically important role in the life cycles of plants especially in harsh desert environments to which A. sphaerocephala is well-adapted. © 2011 Blackwell Publishing Ltd.

  17. THE EFFECTS OF SEED SOAKING WITH PLANT GROWTH REGULATORS ON SEEDLING VIGOR OF WHEAT UNDER SALINITY STRESS

    Directory of Open Access Journals (Sweden)

    Afzal Irfan

    2005-08-01

    Full Text Available Effects of seed soaking with plant growth regulators (IAA, GA3, kinetin or prostart on wheat (Triticum aestivum cv. Auqab-2000 emergence and seedling growth under normal (4 dS/cm and saline (15 dS/cm conditions were studied to determine their usefulness in increasing relative salt-tolerance. During emergence test, emergence percentage and mean emergence time (MET were significantly affected by most of priming treatments, however, root and shoot length, fresh and dry weight of seedlings were significantly increased by 25 ppm kinetin followed by 1% prostart for 2 h treatments under both normal and saline conditions. All pre-sowing seed treatments decreased the electrolyte leakage of steep water as compared to that of non-primed seeds even after 12 h of soaking. Seed soaking with 25 ppm kinetin induced maximum decrease in electrolyte leakage while an increase in electrolyte leakage was observed by 25, 50 or 100 ppm IAA treatments. It is concluded that priming has reduced the severity of the effect of salinity but the amelioration was better due to 25 ppm kinetin and 1% prostart (2 h treatments as these showed best results on seedling growth, fresh and dry weights under non-saline and saline conditions whereas seed soaking with IAA and GA3 were not effective in inducing salt tolerance under present experimental material and conditions.

  18. Mucilage extraction and substrates in the seedling development of yellow passion fruit plants

    Directory of Open Access Journals (Sweden)

    Ricardo Sfeir Aguiar

    2014-02-01

    Full Text Available The object of this work was to evaluate different methods of mucilage extraction and substrates on passion fruit seedling emergence and development , in a mist chamber. Five methods of mucilage extraction were used: water, water + sand, water + virgin whitewash; blender with protected blades and fermentation in water, and three different types of substrates: rice hull, vermiculite and coconut fiber. The experiment had a completely randomized design with five replications in a factorial 5 x 3 scheme (5 extraction methods of seed mucilage and 3 substrates being each parcel composed of 25 seeds. The parameters evaluated were: seedling emergence, speed of emergence index, leaf number, stem length, longest root length, weight of dry matter of roots and shoots. Water and fermentation in water are the best method for mucilage extraction and rice hull and coconut fiber are the best substrate for passionfruit seedling emergence and development.

  19. Database for estimating tree responses of walnut and other hardwoods to ground cover management practices

    Science.gov (United States)

    J.W. Van Sambeek

    2010-01-01

    The ground cover in plantings of walnut and other hardwoods can substantially affect tree growth and seed production. The number of alternative ground covers that have been suggested for establishment in tree plantings far exceeds the number that have already been tested with walnut and other temperate hardwoods. Knowing how other hardwood species respond to ground...

  20. THE CULTURE OF ASIMINA TRILOBA (L. DUNAL SEEDLINGS WITH A VIEW TOWARD THEIR DEVELOPMENT AS PLANTING MATERIAL

    Directory of Open Access Journals (Sweden)

    Beatrice Agneta Szilagyi

    2015-07-01

    Full Text Available Asimina triloba (L. Dunal, an exotic North American temperate-climate species, is little known or appreciated in Europe, especially in Romania. This work, with its goal of remodeling green spaces in Baia Mare by introducing the decorative species Asimina triloba (L. Dunal, proposes to test seedlings of the species in forced cultivation for producing vigorous dendrological material in a reduced time frame. Thus, in the course of experiments that took place from January to May 2014, the ecological valences of Asimina triloba were measured. The pedoclimatic conditions experienced were favorable to the growth and development of the plant in question.

  1. Response of planted ponderosa pine seedlings to weed control by herbicide in western Montana

    Science.gov (United States)

    Fabian C.C. Uzoh

    1999-01-01

    The effects of competing herbaceous vegetation on the growth of ponderosa pine seedlings with and without herbicide Pronone were characterized in this 1987-1990 study. Study areas were established in 36 plantations across western Montana on Champion International Corporation's timberland (currently owned by Plum Creek Timber Company). The study sites were divided...

  2. Inoculation of Loblolly Pine Seedlings at Planting with Basidiospores of Ectomycorrhizal Fungi in Chip Form

    Science.gov (United States)

    Peter R. Beckjord; Marla S. McIntosh; Edward Hacskaylo; John H. Jr. Melhuish; John H. Jr. Melhuish

    1984-01-01

    Basidiospores of the ectomycorrhizae-forming fungi Pisolithus tinctorius and Scleroderma auranteum incorporated into an organic hydrocolloid can be used successfully in field inoculation. Containerized loblolly pine seedlings were inoculated during outplanting by this method. This study showed that basidiospore chips were effective inocula in this investigation.

  3. Loblolly pine seedling response to competition from exotic vs. native plants

    Science.gov (United States)

    Pedram Daneshgar; Shibu Jose; Craig Ramsey; Robin Collins

    2006-01-01

    A field study was conducted in Santa Rosa County, FL to test the hypothesis that an exotic understory would exert a higher degree of competition on tree seedling establishment and growth than native vegetation. The study site was a 60 ha cutover area infested with the invasive exotic cogongrass [Imperata cylindrica (L.) Raeusch.]. A completely...

  4. Fungal and plant gene expression during the colonization of cacao seedlings by endophytic isolates of four Trichoderma species.

    Science.gov (United States)

    Bailey, B A; Bae, H; Strem, M D; Roberts, D P; Thomas, S E; Crozier, J; Samuels, G J; Choi, Ik-Young; Holmes, K A

    2006-11-01

    Endophytic isolates of Trichoderma species are being considered as biocontrol agents for diseases of Theobroma cacao (cacao). Gene expression was studied during the interaction between cacao seedlings and four endophytic Trichoderma isolates, T. ovalisporum-DIS 70a, T. hamatum-DIS 219b, T. harzianum-DIS 219f, and Trichoderma sp.-DIS 172ai. Isolates DIS 70a, DIS 219b, and DIS 219f were mycoparasitic on the pathogen Moniliophthora roreri, and DIS 172ai produced metabolites that inhibited growth of M. roreri in culture. ESTs (116) responsive to endophytic colonization of cacao were identified using differential display and their expression analyzed using macroarrays. Nineteen cacao ESTs and 17 Trichoderma ESTs were chosen for real-time quantitative PCR analysis. Seven cacao ESTs were induced during colonization by the Trichoderma isolates. These included putative genes for ornithine decarboxylase (P1), GST-like proteins (P4), zinc finger protein (P13), wound-induced protein (P26), EF-calcium-binding protein (P29), carbohydrate oxidase (P59), and an unknown protein (U4). Two plant ESTs, extensin-like protein (P12) and major intrinsic protein (P31), were repressed due to colonization. The plant gene expression profile was dependent on the Trichoderma isolate colonizing the cacao seedling. The fungal ESTs induced in colonized cacao seedlings also varied with the Trichoderma isolate used. The most highly induced fungal ESTs were putative glucosyl hydrolase family 2 (F3), glucosyl hydrolase family 7 (F7), serine protease (F11), and alcohol oxidase (F19). The pattern of altered gene expression suggests a complex system of genetic cross talk occurs between the cacao tree and Trichoderma isolates during the establishment of the endophytic association.

  5. Effect of storage temperature and duration on cold hardiness and dormancy of northern red oak seedlings: use of the electrolyte leakage procedure

    Science.gov (United States)

    Barrett C. Wilson; Douglass F. Jacobs

    2005-01-01

    Electrolyte leakage (EL) has successfully predicted cold hardiness of conifer seedlings in both research and commercial settings. EL has also been performed experimentally on European hardwood species. The objective of our study was to determine if further refinement and adjustment of EL methodology to account for the unique characteristics of hardwood seedlings (e.g...

  6. Susceptibility of peach GF 305 seedlings and selected herbaceous plants to plum pox virus isolates from western Slovakia.

    Science.gov (United States)

    Glasa, M; Matisová, J; Hricovský, I; Kúdela, O

    1997-12-01

    The susceptibility of peach GF 305 seedlings and herbaceous plants to five plum pox virus (PPV) isolates from orchards of western Slovakia was investigated. PPV was isolated from diseased plum, apricot and peach trees, and transmitted by chip-budding to peach GF 305. The herbaceous plants were infected by mechanical inoculation. The transmission was analysed by symptomatology and double sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Infected peaches developed leaf distortion, tissue clearing along the veins and small chlorotic spots (isolate BOR-3). With exception of BOR-3, the PPV isolates transmitted from peach caused local chlorotic spots on Chenopodium foetidum. The character of symptoms changed when a sap from PPV-infected Nicotiana benthamiana was used as virus inoculum. From N. benthamiana, the PPV isolates could be transmitted to Pisum sativum, cv. Colmo (light green mosaic), N. clevelandii and N. clevelandii x N. glutinosa hybrid (latent infection or chlorotic spots).

  7. Seedling lethality in Nicotiana plumbaginifolia conferred by Ds transposable element insertion into a plant-specific gene.

    Science.gov (United States)

    Majira, Amel; Domin, Monique; Grandjean, Olivier; Gofron, Krystyna; Houba-Hérin, Nicole

    2002-10-01

    A seedling lethal mutant of Nicotiana plumbaginifolia (sdl-1) was isolated by transposon tagging using a maize Dissociation (Ds) element. The insertion mutation was produced by direct co-transformation of protoplasts with two plasmids: one containing Ds and a second with an Ac transposase gene. sdl-1 seedlings exhibit several phenotypes: swollen organs, short hypocotyls in light and dark conditions, and enlarged and multinucleated cells, that altogether suggest cell growth defects. Mutant cells are able to proliferate under in vitro culture conditions. Genomic DNA sequences bordering the transposon were used to recover cDNA from the normal allele. Complementation of the mutant phenotype with the cDNA confirmed that the transposon had caused the mutation. The Ds element was inserted into the first exon of the open reading frame and the homozygous mutant lacked detectable transcript. Phenocopies of the mutant were obtained by an antisense approach. SDL-1 encodes a novel protein found in several plant genomes but apparently missingfrom animal and fungal genomes; the protein is highly conserved and has a potential plastid targeting motif.

  8. Effects of understory vegetation and litter on plant nitrogen (N, phosphorus (P, N:P ratio and their relationships with growth rate of indigenous seedlings in subtropical plantations.

    Directory of Open Access Journals (Sweden)

    Jun Wang

    Full Text Available Establishing seedlings in subtropical plantations is very important for forest health, succession and management. Information on seedling nutrient concentrations is essential for both the selection of suitable indigenous tree species to accelerate succession of the established plantation and sustainable forest management. In this study, we investigated the concentrations of nitrogen ([N], phosphorus ([P], and N:P ratio in leaves, stems and roots of seedlings of three indigenous tree species (Castanopsis chinensis, Michelia chapensis and Psychotria rubra transplanted with removing or retaining understory vegetation and litter at two typical subtropical forest plantations (Eucalyptus plantation and native species plantation. We also measured the relative growth rate (RGR of seedling height, and developed the relationships between RGR and leaf [N], [P] and N:P ratio. Results showed that treatments of understory vegetation and associated litter (i.e. removal or retained generally had no significant effects on leaf [N], [P], N:P ratio and RGR of the transplanted tree seedlings for the experimental period. But among different species, there were significant differences in nutrient concentrations. M. chapensis and P. rubra had higher [N] and [P] compared to C. chinensis. [N] and [P] also varied among different plant tissues with much higher values in leaves than in roots for all indigenous species. RGR of indigenous tree seedlings was mostly positively correlated with leaf [N] and [P], but negatively correlated with leaf N:P ratio. Considering the low [P] and high N:P ratio observed in the introduced indigenous tree seedlings, we propose that the current experimental plantations might be P limited for plant growth.

  9. Technological advances in temperate hardwood tree improvement including breeding and molecular marker applications

    Science.gov (United States)

    Paula M. Pijut; Keith E. Woeste; G. Vengadesan

    2007-01-01

    Hardwood forests and plantations are an important economic resource for the forest products industry worldwide and to the international trade of lumber and logs. Hardwood trees are also planted for ecological reasons, for example, wildlife habitat, native woodland restoration, and riparian buffers. The demand for quality hardwood from tree plantations will continue to...

  10. Early plant growth and biochemical responses induced by Azospirillum brasilense Sp245 lipopolysaccharides in wheat (Triticum aestivum L.) seedlings are attenuated by procyanidin B2.

    Science.gov (United States)

    Vallejo-Ochoa, Juan; López-Marmolejo, Mariel; Hernández-Esquivel, Alma Alejandra; Méndez-Gómez, Manuel; Suárez-Soria, Laura Nicolasa; Castro-Mercado, Elda; García-Pineda, Ernesto

    2018-03-01

    This study analyzes the effects of procyanidin B2 on early wheat plant growth and plant biochemical responses promoted by lipopolysaccharides (LPS) derived from the rhizobacteria Azospirillum brasilense Sp245. Measurements of leaf, root length, fresh weight, and dry weight showed in vitro plant growth stimulation 4 days after treatment with A. brasilense as well as LPS. Superoxide anion (O 2 ·- ) and hydrogen peroxide (H 2 O 2 ) levels increased in seedling roots treated with LPS (100 μg mL -1 ). The chlorophyll content in leaf decreased while the starch content increased 24 h after treatment in seedling roots. The LPS treatment induced a high increase in total peroxidase (POX) (EC 1.11.1.7) activity and ionically bound cell wall POX content in roots, when compared to respective controls. Early plant growth and biochemical responses observed in wheat seedlings treated with LPS were inhibited by the addition of procyanidin B2 (5 μg mL -1 ), a B type proanthocyanidin (PAC), plant-derived polyphenolic compound with binding properties of LPS. All results suggest first that the ionically bound cell wall POX enzymes could be a molecular target of A. brasilense LPS, and second that the recognition or association of LPS by plant cells is required to activate plant responses. This last event could play a critical role during plant growth regulation by A. brasilense LPS.

  11. Wheat transcription factor TaWRKY70 is positively involved in high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici

    Science.gov (United States)

    Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease of wheat (Triticum aestivum) worldwide. Wheat high-temperature seedling-plant (HTSP) resistance to Pst is non-race-specific and durable. WRKY transcription factors have proven to play important roles in ...

  12. Effects of site preparation treatments on early growth and survival of planted longleaf pine (Pinus palustris Mill.) seedlings in North Carolina

    Science.gov (United States)

    Benjamin O. Knapp; G. Geoff Wang; Joan L. Walker; Susan Cohen

    2006-01-01

    We tested the effects of eight site preparation treatments on early growth and survival of container-grown longleaf pine (Pinus palustris Mill.) seedlings. Treatments included an untreated check, six combinations of two initial vegetation control treatments (chopping or herbicide) with three planting site conditions (flat [no additional treatment],...

  13. Effect of length of interval between cereal rye cover crop termination and corn planting on seedling root disease and corn growth

    Science.gov (United States)

    Cereal rye cover crops terminated immediately before corn planting can sometimes reduce corn population, early growth, and yield. We hypothesized that cereal rye may act as a green bridge for corn pathogens and may increase corn seedling root disease. A field experiment was conducted over two years ...

  14. EFFECTS OF SOME PLANT GROWTH REGULATORS ON JASMONIC ACID INDUCED INHIBITION OF SEED GERMINATION AND SEEDLING GROWTH OF BARLEY

    Directory of Open Access Journals (Sweden)

    Kürşat ÇAVUŞOĞLU

    2009-02-01

    Full Text Available Abstract: The effects of gibberellic acid, kinetin, benzyladenine, ethylene, 24-epibrassinolide and polyamines (spermine, spermidine, putrescine, cadaverine on jasmonic acid inhibition of seed germination and seedling growth of barley were studied. All of the plant growth regulators studied were determined to have a succesful performance in reversing of the inhibitory effects of jasmonic acid on the seed germination and seedling growth. Moreover, the above mentioned growth regulators overcame the inhibitory effect of JA on the percentages of germination and coleoptile emergence in the same ratio, while GA3 was the most successful hormone on the fresh weight and radicle and coleoptile elongation in comparison with the other growth regulators. Key words: Barley, jasmonic acid, plant growth regulator, seed germination, seedling growth ARPANIN TOHUM ÇİMLENMESİ VE FİDE BÜYÜMESİNİN JASMONİK ASİT TEŞVİKLİ İNHİBİSYONU ÜZERİNE BAZI BİTKİ BÜYÜME DÜZENLEYİCİLERİNİN ETKİLERİ Özet: Arpanın tohum çimlenmesi ve fide büyümesinin jasmonik asit inhibisyonu üzerine gibberellik asit, kinetin, benziladenin, etilen, 24-epibrassinolit ve poliaminlerin (spermin, spermidin, putressin, kadaverin etkileri araştırılmıştır. Çalışılan bitki büyüme düzenleyicilerinin tümünün tohum çimlenmesi ve fide büyümesi üzerinde jasmonik asitin engelleyici etkisini tersine çevirmede başarılı bir performansa sahip oldukları belirlenmiştir. Dahası, yukarıda sözü edilen büyüme düzenleyicileri çimlenme ve koleoptil çıkış yüzdeleri üzerinde aynı oranda etkili olurken, taze ağırlık ve radikula ve koleoptil uzaması üzerinde diğer büyüme düzenleyicileri ile karşılaştırıldığında en başarılı hormon GA3 olmuştur. Anahtar kelimeler: Arpa, jasmonik asit, bitki büyüme düzenleyicisi, tohum çimlenmesi, fide büyümesi

  15. Effect of NaCl salinity on the germination and seedling growth of some medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad, Z; Hussain, F [University of Peshawar (Pakistan). Dept. of Botany

    2010-04-15

    Seeds of Lepidium sativum L., Linum usitatissimum L., Plantago ovata Forssk., and Trigonella foenum-graecum L. were tested in 0.05 (Control), 2.5, 5.0, 7.5, 10.0, 12.5, or 15.0 dS/m concentration of NaCl. ANOVA revealed highly significant differences for plumule growth while germination percentage, radicle growth, seedling fresh and dry weight and moisture contents showed non-significant variation under various salt concentrations. However, the differences among the species for all the parameters studied were highly significant. The findings suggest that these medicinal species might tolerate moderate levels of salinity and can be tried for cultivation on marginal salted soils. (author)

  16. Effect of NaCl salinity on the germination and seedling growth of some medicinal plants

    International Nuclear Information System (INIS)

    Muhammad, Z.; Hussain, F.

    2010-01-01

    Seeds of Lepidium sativum L., Linum usitatissimum L., Plantago ovata Forssk., and Trigonella foenum-graecum L. were tested in 0.05 (Control), 2.5, 5.0, 7.5, 10.0, 12.5, or 15.0 dS/m concentration of NaCl. ANOVA revealed highly significant differences for plumule growth while germination percentage, radicle growth, seedling fresh and dry weight and moisture contents showed non-significant variation under various salt concentrations. However, the differences among the species for all the parameters studied were highly significant. The findings suggest that these medicinal species might tolerate moderate levels of salinity and can be tried for cultivation on marginal salted soils. (author)

  17. Vegetative and seedling regeneration of pin cherry (Prunus pensylvanica): Efficacy of herbicide treatment. NODA note No. 21

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, A U; Bell, F W; Peterson, G W

    1996-11-01

    Pin cherry (Prunus pensylvanica L.) is a major competing plant commonly found in young conifer plantations in both boreal and northern hardwood forests. This note describes and presents results of a study conducted to determine, for pin cherry, the ratio of the current year`s seedling recruitment versus the previous year`s stem density; seed production; the soil seed bank; and the efficacy of a glyphosate herbicide treatment to control this competitor. The study was carried out in a seven-year-old jack pine plantation north of Atikokan, Ontario.

  18. Influence of mineral nutrition on susceptibility and recovery of planted seedlings of ungulate browse

    Science.gov (United States)

    Owen T. Burney; Douglass F. Jacobs

    2010-01-01

    Efforts to minimize animal damage during reforestation in the Oregon Coast Range have had little success. Enhancing plant mineral nutrition via application of controlled-release fertilization at the time of planting may provide some relief from ungulate browse pressure due to increased height growth, but associated impacts on susceptibility of fertilized plants to...

  19. Arbuscular Mycorrhizal Fungus Species Dependency Governs Better Plant Physiological Characteristics and Leaf Quality of Mulberry (Morus alba L.) Seedlings.

    Science.gov (United States)

    Shi, Song-Mei; Chen, Ke; Gao, Yuan; Liu, Bei; Yang, Xiao-Hong; Huang, Xian-Zhi; Liu, Gui-Xi; Zhu, Li-Quan; He, Xin-Hua

    2016-01-01

    Understanding the synergic interactions between arbuscular mycorrhizal fungi (AMF) and its host mulberry (Morus alba L.), an important perennial multipurpose plant, has theoretical and practical significance in mulberry plantation, silkworm cultivation, and relevant textile industry. In a greenhouse study, we compared functional distinctions of three genetically different AMF species (Acaulospora scrobiculata, Funneliformis mosseae, and Rhizophagus intraradices) on physiological and growth characteristics as well as leaf quality of 6-month-old mulberry seedlings. Results showed that mulberry was AMF-species dependent, and AMF colonization significantly increased shoot height and taproot length, stem base and taproot diameter, leaf and fibrous root numbers, and shoot and root biomass production. Meanwhile, leaf chlorophyll a or b and carotenoid concentrations, net photosynthetic rate, transpiration rate and stomatal conductance were generally significantly greater, while intercellular CO2 concentration was significantly lower in AMF-inoculated seedlings than in non-AMF-inoculated counterparts. These trends were also generally true for leaf moisture, total nitrogen, all essential amino acids, histidine, proline, soluble protein, sugar, and fatty acid as they were significantly increased under mycorrhization. Among these three tested AMFs, significantly greater effects of AMF on above-mentioned mulberry physiological and growth characteristics ranked as F. mosseae > A. scrobiculata > R. intraradices, whilst on mulberry leaf quality (e.g., nutraceutical values) for better silkworm growth as F. mosseae ≈A. scrobiculata > R. intraradices. In conclusion, our results showed that greater mulberry biomass production, and nutritional quality varied with AMF species or was AMF-species dependent. Such improvements were mainly attributed to AMF-induced positive alterations of mulberry leaf photosynthetic pigments, net photosynthetic rate, transpiration rate, and N

  20. Internalisation potential of Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica subsp. enterica serovar Typhimurium and Staphylococcus aureus in lettuce seedlings and mature plants.

    Science.gov (United States)

    Standing, Taryn-Ann; du Plessis, Erika; Duvenage, Stacey; Korsten, Lise

    2013-06-01

    The internalisation potential of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli O157:H7 and Salmonella enterica subsp. enterica serovar Typhimurium in lettuce was evaluated using seedlings grown in vermiculite in seedling trays as well as hydroponically grown lettuce. Sterile distilled water was spiked with one of the four human pathogenic bacteria (10(5) CFU/mL) and used to irrigate the plants. The potential for pathogen internalisation was investigated over time using light microscopy, transmission electron microscopy and viable plate counts. Additionally, the identities of the pathogens isolated from internal lettuce plant tissues were confirmed using polymerase chain reaction with pathogen-specific oligonucleotides. Internalisation of each of the human pathogens was evident in both lettuce seedlings and hydroponically grown mature lettuce plants. To our knowledge, this is the first report of S. aureus internalisation in lettuce plants. In addition, the levels of background microflora in the lettuce plants were determined by plate counting and the isolates identified using matrix-assisted laser ionisation-time of flight (MALDI-TOF). Background microflora assessments confirmed the absence of the four pathogens evaluated in this study. A low titre of previously described endophytes and soil inhabitants, i.e., Enterobacter cloacae, Enterococcus faecalis, Lysinibacillus fusiformis, Rhodococcus rhodochrous, Staphylococcus epidermidis and Staphylococcus hominis were identified.

  1. Decarboxylation of indole-3-acetic acid and inhibition of growth in Avena sativa seedlings by plant-derived photosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, T.M. [Dickinson Coll., Carlisle, PA (United States). Dept. of Biology

    1996-12-01

    A number of plant phototoxins, when supplemented with UVA (320-400 nm) radiation, are capable of sensitizing the decomposition of indole-3-acetic acid (IAA), as measured by release of {sup 14}CO{sub 2} from carboxyl-labeled IAA. Alpha-terthienyl ({alpha}T) and harmine caused significant rates of IAA decarboxylation at concentrations as low as 1 nM and were approximately 80% as effective as riboflavin and flavin mononucleotide. Partial inhibition by sodium azide indicates that the {alpha}T-induced decarboxylation of IAA is predominately, but not entirely, a type II reaction mediated by singlet oxygen. Based on changes in UV absorption spectra, it appears that the hormones gibberellic acid, abscisic acid and 6-benzylaminopurine (a cytokinin) are less susceptible to photosensitized decomposition than is IAA. Alpha-terthienyl plus UVA also inhibited elongation growth and reduced endogenous IAA levels in Avena sativa L. coleoptile sections and promoted senescence in intact Avena seedlings. These results confirm the alelopathic potential of plant photosensitizers such as {alpha}T and indicate that the phytohormone IAA may represent an additional target for the action of photosensitizers. (Author).

  2. Effect of plant growth regulators on indirect shoot organogenesis of Ficus religiosa through seedling derived petiole segments

    Directory of Open Access Journals (Sweden)

    Mohsen Hesami

    2018-06-01

    Full Text Available Ficus religiosa is known as a long-lived multipurpose forest tree. The tree plays an important role for religious, medicinal, and ornamental purposes. However, the propagation rate of Ficus religiosa is low in natural habitat so the plant tissue culture techniques are an applicable method for multiplication of this valuable medicinal plants. Thus, the aim of this study is to understand the effect of different auxin/cytokinin ratios on indirect shoot organogenesis of this plant. According to our results, the maximum callus induction frequency (100% was obtained on Murashige and Skoog (MS medium supplemented with 0.5 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D plus 0.05 mg/l 6-benzylaminopurine (BAP from petiole segments. For shoot induction purpose, the yellow-brownish, friable, organogenic calli were inoculated on shoot induction medium. On MS medium supplemented with 1.5 mg/l BAP and 0.15 mg/l Indole-3-butyric acid (IBA, 96.66% of the petiole-derived calli responded with an average number of 3.56 shoots per culture. The highest root formation frequency (96.66%, root number (5.5, and root length (4.83 cm were achieved on MS medium containing 2.0 mg/l IBA plus 0.1 mg/l Naphthaleneacetic acid (NAA. The rooted shoots were successfully transferred to field condition and the substrate with the mixture of cocopeat and perlite (1:1 had the highest survival rate (96.66%. This is the first report of an effective in vitro organogenesis protocol for F. religiosa by indirect shoot organogenesis through axenic seedling derived petiole explants, which can be efficiently employed for conservation of this important medicinal plant species as well as the utilization of active biomolecules. Keywords: Callus formation, Multiplication, Acclimatization, Growth regulators ratio

  3. Effects of plant-soil feedback on tree seedling growth under arid conditions

    NARCIS (Netherlands)

    Meijer, S.S.; Holmgren, M.; Putten, van der W.H.

    2011-01-01

    Aims: Plants are able to influence their growing environment by changing biotic and abiotic soil conditions. These soil conditions in turn can influence plant growth conditions, which is called plant–soil feedback. Plant–soil feedback is known to be operative in a wide variety of ecosystems ranging

  4. Fertilizing Southern Hardwoods

    Science.gov (United States)

    W. M. Broadfoot; A. F. Ike

    1967-01-01

    If present trends continue, fertilizing may soon be economically feasible in southern hardwood stands. Demands for the wood are rising, and the acreage alloted for growing it is steadily shrinking. To supply anticipated requests for information, the U. S. Forest Service has established tree nutrition studies at the Southern Hardwoods Laboratory in Stoneville,...

  5. Production and early field performance of RPM® seedlings in Missouri floodplains

    Science.gov (United States)

    Daniel C. Dey; Wayne Lovelace; John M. Kabrick; Michael A. Gold

    2004-01-01

    A new nursery culture process has been developed to produce large container RPM? seedlings in an effort to improve the success in artificially regenerating hardwoods. Major features of the process include air root pruning of seedlings grown in a well aerated soil medium to encourage a dense, fibrous root system. Production has focused on native bottomland tree, shrub,...

  6. The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

    Science.gov (United States)

    Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

    2009-04-01

    Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

  7. Comparative gas-exchange in leaves of intact and clipped, natural and planted cherrybark oak (Quercus pagoda Raf.) seedlings

    Science.gov (United States)

    Brian R. Lockhart; John D. Hodges

    2005-01-01

    Gas-exchange measurements, including C022-exchange rate (net photosynthesis), stomatal conductance, and transpiration, were conducted on intact and clipped cherrybark oak (Quercus pagoda Raf.) seedlings growing in the field and in a nursery bed. Seedlings in the field, released from midstory and understory woody competition,...

  8. Relating leaf photosynthetic rate to whole-plant growth: drought and shade effects on seedlings of four Quercus species

    NARCIS (Netherlands)

    Quero Perez, J.L.; Villar, R.; Marañón, T.; Zamora, R.; Vega, D.; Sack, L.

    2008-01-01

    Understanding the impacts of combined resource supplies on seedlings is critical to enable prediction of establishment growth, and forest dynamics. We investigated the effects of irradiance and water treatments on absolute growth, and relative growth rate (RGR) and its components, for seedlings of

  9. Response of northern red oak, black walnut, and white ash seedlings to various levels of simulated summer deer browsing

    Science.gov (United States)

    Robert C. Morrissey; Douglass F. Jacobs; John R. Seifert

    2008-01-01

    Understanding the response of tree seedlings to browsing by white-tailed deer (Odocoileus virginianus Zimmerman) is critical to the management of high value hardwood plantations in the Central Hardwood Forest Region. One-year-old black walnut (Juglans nigra L.), northern red oak (Quercus rubra L.), and white ash...

  10. Relevance of Vṛkṣāyurveda and other traditional methods for organic production of nursery seedlings of useful plants

    Directory of Open Access Journals (Sweden)

    Geetha Suresh

    2013-01-01

    Full Text Available Plant propagation is critical to augment the resource and has been the main concern for farmers and planters through history. India has evolved the science of Vṛkṣāyurveda to address the above issue. An effort is made here to review Vṛkṣāyurveda literature related to nursery techniques. Different libraries were visited and relevant review material obtained by hand search and from databases. Interaction with Sanskrit scholars and eminent scientists working in the field of Vṛkṣāyurveda, as well as the efforts of the authors of this paper, helped in the selection of pertinent literature. In the absence of original texts, authentic translations of the publications were referred. A conscious decision was made to limit the search to the fields of seed storage, pretreatment and nutrition of seedlings. To have a comparative account recent trends and literature on nursery technology were also examined. This was supplemented by interviews with traditional organic farmers. Our survey revealed that the time period of the literature pertaining to Vṛkṣāyurveda ranges from BCE 1200 to the present times. The subject has evolved from morphological descriptions and uses of plants, in texts such as R.gveda and Atharvaveda, to treatises dedicated solely to the art of growing plants like Kṛṣi-Parāśara and Vṛkṣāyurveda. It is also evident that there were important periods when more works appeared across subjects such as water divining, soil types, seed collection and storage, propagation, germination and sprouting, watering regimen, pest, and disease control. The review revealed that valuable information pertaining to nursery techniques is available in Vṛkṣāyurveda, which can be used in the development of nursery protocol. This will not only help in effective organic nursery management, but also ensure the health and livelihood security of the communities involved and effective waste management.

  11. Relevance of Vṛkṣāyurveda and other traditional methods for organic production of nursery seedlings of useful plants.

    Science.gov (United States)

    Suresh, Geetha; Haridasan, K; Krishnamurthy, Kulithala Viswanathan

    2013-07-01

    Plant propagation is critical to augment the resource and has been the main concern for farmers and planters through history. India has evolved the science of Vṛkṣāyurveda to address the above issue. An effort is made here to review Vṛkṣāyurveda literature related to nursery techniques. Different libraries were visited and relevant review material obtained by hand search and from databases. Interaction with Sanskrit scholars and eminent scientists working in the field of Vṛkṣāyurveda, as well as the efforts of the authors of this paper, helped in the selection of pertinent literature. In the absence of original texts, authentic translations of the publications were referred. A conscious decision was made to limit the search to the fields of seed storage, pretreatment and nutrition of seedlings. To have a comparative account recent trends and literature on nursery technology were also examined. This was supplemented by interviews with traditional organic farmers. Our survey revealed that the time period of the literature pertaining to Vṛkṣāyurveda ranges from BCE 1200 to the present times. The subject has evolved from morphological descriptions and uses of plants, in texts such as Ṛgveda and Atharvaveda, to treatises dedicated solely to the art of growing plants like Kṛṣi-Parāśara and Vṛkṣāyurveda. It is also evident that there were important periods when more works appeared across subjects such as water divining, soil types, seed collection and storage, propagation, germination and sprouting, watering regimen, pest, and disease control. The review revealed that valuable information pertaining to nursery techniques is available in Vṛkṣāyurveda, which can be used in the development of nursery protocol. This will not only help in effective organic nursery management, but also ensure the health and livelihood security of the communities involved and effective waste management.

  12. Alterations in polyribosome and messenger ribonucleic acid metabolism and messenger ribonucleoprotein utilization in osmotically stressed plant seedlings

    International Nuclear Information System (INIS)

    Mason, H.S.

    1986-01-01

    Polyribosome aggregation state in growing tissues of barley and wheat leaf of stems of pea and squash was studied in relation to seedling growth and water status of the growing tissue in plants at various levels of osmotic stress. It was found to be highly correlated with water potential and osmotic potential of the growing tissue and with leaf of stem elongation rate. Stress rapidly reduced polyribosome content and water status in growing tissues of barley leaves; changes were slow and slight in the non-growing leaf blade. Membrane-bound and free polyribosomes were equally sensitive to stress-induced disaggregation. Incorporation of 32 PO 4 3- into ribosomal RNA was rapidly inhibited by stress, but stability of poly(A) + RNA relative to ribosomal RNA was similar in stressed and unstressed tissues, with a half-life of about 12 hours. Stress also caused progressive loss of poly(A) + RNA from these tissues. Quantitation of poly(A) and in vitro messenger template activity in polysome gradient fractions showed a shift of activity from the polysomal region to the region of 20-60 S in stressed plants. Messenger RNA in the 20-60 S region coded for the same peptides as mRNA found in the polysomal fraction. Nonpolysomal and polysome-derived messenger ribonucleoprotein complexes (mRNP) were isolated, and characteristic proteins were found associated with either fraction. Polysomal mRNP from stressed or unstressed plants were translated with similar efficiency in a wheat germ cell-free system. It was concluded that no translational inhibitory activity was associated with nonpolysomal mRNP from barley prepared as described

  13. Effects of copper-based compounds, antibiotics and a plant activator on population sizes and spread of Clavibacter michiganensis subsp. michiganensis in greenhouse tomato seedlings

    OpenAIRE

    Milijašević Svetlana; Todorović Biljana; Potočnik Ivana; Rekanović Emil; Stepanović Miloš

    2009-01-01

    Three copper-based compounds (copper hydroxide, copper oxychloride, copper sulphate), two antibiotics (streptomycin and kasugamycin) and a plant activator (ASM) significantly reduced population sizes and spread of C. michiganensis subsp. michiganensis among tomato seedlings in the greenhouse. Streptomycin had the best effect in reducing pathogen population size in all sampling regions. Moreover, this antibiotic completely stopped the spread of C. michiganensis subsp. michiganensis in the regi...

  14. Study the effect of salinity levels and seed priming on germination and seedling properties of two medicinal plant species from Asteraceae family

    Directory of Open Access Journals (Sweden)

    M. Kafi

    2016-04-01

    Full Text Available Soil and water sources salinity are important constrains which threat the sustainable agriculture production in Iran. In order to evaluate the effect of different antioxidants and salinity levels on germination and seedling properties of two medicinal species (Cnicus benedictus L., and (Cichorium intybus L., an experiment was conducted using a factorial based on completely randomized design with four replications at Special Crops Laboratory of Ferdowsi University of Mashhad. The studied factor for each plant included: seed priming at 4 levels including control (distilled water, ascorbic acid (40 mM, gibberlic acid (75 mg.lit-1 and salicylic acid (1.5 mM, and five salinity levels according to electrical conductivity by adding NaCl to distilled water (control, 5,10,15 and 20 ds.m-1. According to results, pretreatment with salicylic acid improved all of the germination and seedling properties in Cnicus benedictus L. but gibberlic acid could to improved germination and seedling properties in Cichorium intybus L. species. There were strong correlation between germination rate and radical and caulicle length especially on Cichorium intybus species. Generally, seed priming with gibberlic acid and salicylic acid could improve germination and seedling properties of these two species. Both species showed a reliable tolerance to NaCl salinity at germination stage, and germination was 60% compared with control at 20 ds.m-1 treatment.

  15. Infection and colonization of rice seedlings by the plant growth-promoting bacterium Herbaspirillum seropedicae Z67.

    Science.gov (United States)

    James, Euan K; Gyaneshwar, Prasad; Mathan, Natarajan; Barraquio, Wilfredo L; Reddy, Pallavolu M; Iannetta, Pietro P M; Olivares, Fabio L; Ladha, Jagdish K

    2002-09-01

    A beta-glucoronidase (GUS)-marked strain of Herbaspirillum seropedicae Z67 was inoculated onto rice seedling cvs. IR42 and IR72. Internal populations peaked at over 10(6) log CFU per gram of fresh weight by 5 to 7 days after inoculation (DAI) but declined to 10(3) to 10(4) log CFU per gram of fresh weight by 28 DAI. GUS staining was most intense on coleoptiles, lateral roots, and at the junctions of some of the main and lateral roots. Bacteria entered the roots via cracks at the points of lateral root emergence, with cv. IR72 appearing to be more aggressively infected than cv. IR42. H. seropedicae subsequently colonized the root intercellular spaces, aerenchyma, and cortical cells, with a few penetrating the stele to enter the vascular tissue. Xylem vessels in leaves and stems were extensively colonized at 2 DAI but, in later harvests (7 and 13 DAI), a host defense reaction was often observed. Dense colonies of H. seropedicae with some bacteria expressing nitrogenase Fe-protein were seen within leaf and stem epidermal cells, intercellular spaces, and substomatal cavities up until 28 DAI. Epiphytic bacteria were also seen. Both varieties showed nitrogenase activity but only with added C, and the dry weights of the inoculated plants were significantly increased. Only cv. IR42 showed a significant (approximately 30%) increase in N content above that of the uninoculated controls, and it also incorporated a significant amount of 15N2.

  16. Attempts to Localize and Identify the Gravity-sensing Device of Plant Seedlings

    Science.gov (United States)

    Bandurski, R. S.; Schulze, A.; Momonoki, Y.; Desrosiers, M.; Fearn-Desrosiers, D.

    1985-01-01

    The growth hormone asymmetry develops within three minutes following the initiation of the gravitational asymmetry and radio-labeled compounds being transported from the seed to the shoot also show asymmetric distribution. It is found that the target of the gravity stimulus resides primarily in the permability of the vascular tissue that regulates the supply of hormone to the surrounding tissues. It is hypothesized that the gravitational stimulus induces an asymmetric change in the rate of secretion of the growth hormone, IAA, from the vascular tissue into the surrounding cortical cells. More hormone would be secreted from the vascular stele proximal to the lower side of a horizontally placed plant shoot than from the upper side. This results in more growth hormone in the lower cortical (plus epidermal) cells, and ultimately more growth, such that the plant grows asymmetrically and, ultimately attain its normal vertical orientation. A theory was developed of how plants respond to the gravitational stimulus. The theory is based upon the analytical results concerning the effects of gravity on the distribution of the plant growth hormone, IAA, in both its free and conjugated forms, and upon the effect of the growth stimulis on the distribution of externally applied radio-labeled compounds. Its advantage is that it is testable and that it is built upon solid knowledge of the effects of the gravitational stimulus upon the endogenous growth hormone, IAA, and upon the distribution of externally applied radio-labeled compounds.

  17. A Public Image Database for Benchmark of Plant Seedling Classification Algorithms

    DEFF Research Database (Denmark)

    Giselsson, Thomas Mosgaard; Nyholm Jørgensen, Rasmus; Jensen, Peter Kryger

    A database of images of approximately 960 unique plants belonging to 12 species at several growth stages is made publicly available. It comprises annotated RGB images with a physical resolution of roughly 10 pixels per mm. To standardise the evaluation of classification results obtained...

  18. Responses of seedlings of tropical woody plants to environmental stresses with emphasis on Theobroma cacao and Hevea brasiliensis

    Energy Technology Data Exchange (ETDEWEB)

    Sena Gomes, A.R.

    1987-01-01

    Relative humidity, flooding, temperature, wind, and SO/sub 2/ variously influenced physiological processes and growth of tropical woody plants, with emphasis on three Theobroma cacao varieties and three Hevea brasiliensis families. Stomata were smaller and more numerous in Theobroma than in Hevea. In Theobroma, but not Heavea, stomatal frequency decreased from the leaf base to the apex and from the midrib outward. Stomata of Theobroma cacao var. Catongo opened in high relative humidity (RH) and closed in low RH. The more open stomata in high RH were associated with high rates of photosynthesis, low leaf water potential, high water use efficiency (WUE), and low transpiration rate (TR). Variations in TR and WUE were correlated with changes in vapor pressure deficit. Other responses included stomatal closure, decreased chlorophyll content, leaf epinasty, production of hypertrophied lenticels and adventitious roots, and acceleration of ethylene production. Responses to flooding varied with species, Theobroma varieties and Hevea families. Effects of temperature regimes on growth varied with species, varieties and families, plant parts, growth parameters, and time of harvesting. Optimal temperatures for dry weight increase of stems or roots of Theobroma cacao var. Comum were 22.2 C; and 33.3 C for dry weight increase or relative growth rates of leaves or seedlings. Optimal temperatures for growth varied for Hevea families. Wind injured leaves of Theobroma cacao, with more injury by wind of 6.0 than 3.0 m s/sup -1/. Stomata were more open on windy than on calm days, but tended to close at high wind speeds. Wind lowered transpiration rate but the reduction was not correlated with leaf dehydration. SO/sub 2/ at 0.5, 1.0, or 1.5 ppm for 24 h did not injure Theobroma leaves but reduced dry weight increment of leaves of var. Catongo but not Catongo/Sial.

  19. Flood tolerance of oak seedlings from bottomland and upland sites

    Science.gov (United States)

    Michael P. Walsh; Jerry Van Sambeek; Mark Coggeshall; David. Gwaze

    2009-01-01

    Artificial regeneration of oak species in floodplains presents numerous challenges because of the seasonal flooding associated with these areas. Utilizing not only flood-tolerant oak species, but also flood tolerant seed sources of the oak species, may serve to enhance seedling survival and growth rates. Despite the importance of these factors to hardwood forest...

  20. Effects of seed and seedling predation by small mammals on ...

    African Journals Online (AJOL)

    Seed predation reduced seedling recruitment from seeds planted in March 1986 in mature fynbos, but ... Seed predation did not significantly reduce seedling recruitment from seed planted in July, August and ... AJOL African Journals Online.

  1. Influence of flooding and landform properties on riparian plant communities in an old-growth northern hardwood watershed

    Science.gov (United States)

    P. Charles Goebel; Kurt S. Pregitzer; Brian J. Palik

    2012-01-01

    In most forested landscapes, the organization of plant communities across stream valleys is thought to be regulated by a complex set of interactions including flooding, landform properties, and vegetation. However, few studies have directly examined the relative influence of frequent and infrequent flooding, as well as landform properties, on riparian plant community...

  2. Alfalfa seedlings grown outdoors are more resistant to UV-induced DNA damage than plants grown in a UV-free environmental chamber

    International Nuclear Information System (INIS)

    Takayanagi, Shinnosuke; Trunk, J.G.; Sutherland, J.C.; Sutherland, B.M.

    1994-01-01

    The relative UV sensitivities of alfalfa seedlings grown outdoors versus plants grown in a growth chamber under UV-filtered cool white fluorescent bulbs have been determined using three criteria: (1) level of endogenous DNA damage as sites for the UV endonuclease from Micrococcus luteus, (2) susceptibility to pyrimidine dimer induction by a UV challenge exposure and (3) ability to repair UV-induced damage. We find that outdoor-grown plants contain approximately equal frequencies of endogenous DNA damages, are less susceptible to dimer induction by a challenge exposure of broad-spectrum UV and photorepair dimers more rapidly than plants grown in an environmental chamber under cool white fluorescent lamps plus a filter removes most UV radiation. These data suggest that plants grown in a natural environment would be less sensitive to UVB-induced damage than would be predicted on the basis of studies on plants grown under minimum UV. (author)

  3. Seedling emergence response of rare arable plants to soil tillage varies by species.

    Science.gov (United States)

    Torra, Joel; Recasens, Jordi; Royo-Esnal, Aritz

    2018-01-01

    Very little information is available on emergence of rare arable plants (RAP) in relation to soil disturbance and seed burial conditions in Europe. This information is essential to design conservation and soil management strategies to prevent the decline of these species in agroecosystems. The objective of this research was to investigate the effect of soil cultivation with burial time on the emergence and seed persistence of RAP. Seeds of 30 RAP species were collected from Spanish arable fields and subjected to two tillage treatments: (a) no soil disturbance, and (b) autumnal soil disturbance down to 10 cm depth every year. The treatments simulated no-till and tilled (disking), respectively. In plots under no-till, RAP seeds were sown at 1-cm depth. In the tilled plots, seeds were sown homogeneously mixed in the top 1-10 cm of soil. The trial was established every two consecutive seasons, and each trial was maintained for two years. Annual cumulative plant emergence was calculated each year; whereas the first trial was monitored for a third year to estimate seed longevity using a persistence index. The response in emergence of the 30 RAP to annual tillage varied among species. With burial time (number of years), higher emergence was observed for seeds sown in tilled soil. This was true across all species, and with strong season effects. The persistence index was correlated with seed weight, species with bigger seeds had low persistence indices while no pattern was observed for small seeded species. Most RAP species, particularly those with high persistence, showed induction of secondary dormancy processes, highlighting the importance of tillage to promote RAP emergence, and hence, seed bank replenishment. Therefore, as time passes the absence of soil tillage may represent a driver of RAP seed bank decline for those species with secondary dormancy processes. In conclusion, it is important to design soil management strategies, such as regular tillage to promote

  4. Development of hardwood seed zones for Tennessee using a geographic information system

    Science.gov (United States)

    Post, L.S.; Schlarbaum, S.E.; Van Manen, F.; Cecich, R.A.; Saxton, A.M.; Schneider, J.F.

    2003-01-01

    For species that have no or limited information on genetic variation and adaptability to nonnative sites, there is a need for seed collection guidelines based on biological, climatological, and/or geographical criteria. Twenty-eight hardwood species are currently grown for reforestation purposes at the East Tennessee State Nursery. The majority of these species have had no genetic testing to define guidelines for seed collection location and can be distributed to sites that have a very different environment than that of seed origin(s). Poor survival and/or growth may result if seedlings are not adapted to environmental conditions at the planting location. To address this problem, 30 yr of Tennessee county precipitation and minimum temperature data were analyzed and grouped using a centroid hierarchical cluster analysis. The weather data and elevational data were entered into a Geographic Information System (GIS) and separately layered over Bailey's Ecoregions to develop a seed zone system for Tennessee. The seed zones can be used as a practical guideline for collecting seeds to ensure that the resulting seedlings will be adapted to planting environments.

  5. Regulation of Plant Growth, Photosynthesis, Antioxidation and Osmosis by an Arbuscular Mycorrhizal Fungus in Watermelon Seedlings under Well-Watered and Drought Conditions

    Science.gov (United States)

    Mo, Yanling; Wang, Yongqi; Yang, Ruiping; Zheng, Junxian; Liu, Changming; Li, Hao; Ma, Jianxiang; Zhang, Yong; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Drought stress has become an increasingly serious environmental issue that influences the growth and production of watermelon. Previous studies found that arbuscular mycorrhizal (AM) colonization improved the fruit yield and water use efficiency (WUE) of watermelon grown under water stress; however, the exact mechanisms remain unknown. In this study, the effects of Glomus versiforme symbiosis on the growth, physio-biochemical attributes, and stress-responsive gene expressions of watermelon seedlings grown under well-watered and drought conditions were investigated. The results showed that AM colonization did not significantly influence the shoot growth of watermelon seedlings under well-watered conditions but did promote root development irrespective of water treatment. Drought stress decreased the leaf relative water content and chlorophyll concentration, but to a lesser extent in the AM plants. Compared with the non-mycorrhizal seedlings, mycorrhizal plants had higher non-photochemical quenching values, which reduced the chloroplast ultrastructural damage in the mesophyll cells and thus maintained higher photosynthetic efficiency. Moreover, AM inoculation led to significant enhancements in the enzyme activities and gene expressions of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and O2− compared with non-mycorrhizal plants. Under drought stress, the soluble sugar and proline contents were significantly increased, and further enhancements were observed by pre-treating the drought-stressed plants with AM. Taken together, our findings indicate that mycorrhizal colonization enhances watermelon drought tolerance through a stronger root system, greater protection of photosynthetic apparatus, a more efficient antioxidant system and improved osmoregulation. This study contributes to advances

  6. Regulation of Plant Growth, Photosynthesis, Antioxidation and Osmosis by an Arbuscular Mycorrhizal Fungus in Watermelon Seedlings under Well-Watered and Drought Conditions.

    Science.gov (United States)

    Mo, Yanling; Wang, Yongqi; Yang, Ruiping; Zheng, Junxian; Liu, Changming; Li, Hao; Ma, Jianxiang; Zhang, Yong; Wei, Chunhua; Zhang, Xian

    2016-01-01

    Drought stress has become an increasingly serious environmental issue that influences the growth and production of watermelon. Previous studies found that arbuscular mycorrhizal (AM) colonization improved the fruit yield and water use efficiency (WUE) of watermelon grown under water stress; however, the exact mechanisms remain unknown. In this study, the effects of Glomus versiforme symbiosis on the growth, physio-biochemical attributes, and stress-responsive gene expressions of watermelon seedlings grown under well-watered and drought conditions were investigated. The results showed that AM colonization did not significantly influence the shoot growth of watermelon seedlings under well-watered conditions but did promote root development irrespective of water treatment. Drought stress decreased the leaf relative water content and chlorophyll concentration, but to a lesser extent in the AM plants. Compared with the non-mycorrhizal seedlings, mycorrhizal plants had higher non-photochemical quenching values, which reduced the chloroplast ultrastructural damage in the mesophyll cells and thus maintained higher photosynthetic efficiency. Moreover, AM inoculation led to significant enhancements in the enzyme activities and gene expressions of superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase in watermelon leaves upon drought imposition. Consequently, AM plants exhibited lower accumulation of MDA, H2O2 and [Formula: see text] compared with non-mycorrhizal plants. Under drought stress, the soluble sugar and proline contents were significantly increased, and further enhancements were observed by pre-treating the drought-stressed plants with AM. Taken together, our findings indicate that mycorrhizal colonization enhances watermelon drought tolerance through a stronger root system, greater protection of photosynthetic apparatus, a more efficient antioxidant system and improved osmoregulation. This study contributes

  7. Timber, Browse, and Herbage on Selected Loblolly-Shortleaf Pine-Hardwood Forest Stands

    Science.gov (United States)

    Gale L. Wolters; Alton Martin; Warren P. Clary

    1977-01-01

    A thorough vegetation inventory was made on loblolly-shortleaf pine-hardwood stands scheduled by forest industry for clearcutting, site preparation, and planting to pine in north central Louisiana and southern Arkansas. Overstory timber, on the average, contained about equal proportions of softwood and hardwood basal area. Browse plants ranged from 5,500 to over 70,...

  8. Response of herbaceous plant community diversity and composition to overstorey harvest within riparian management zones in Northern Hardwoods

    Science.gov (United States)

    Eric K. Zenner; Michelle A. Martin; Brian J. Palik; Jerilynn E. Peck; Charles R. Blinn

    2013-01-01

    Partial timber harvest within riparian management zones (RMZs) may permit active management of riparian forests while protecting stream ecosystems, but impacts on herbaceous communities are poorly understood. We compared herbaceous plant community abundance, diversity and composition in RMZs along small streams in northern Minnesota, USA, among four treatments before...

  9. Herbicide options for hardwood management

    Science.gov (United States)

    Andrew W. Ezell; A. Brady Self

    2016-01-01

    The use of herbicides in hardwood management presents special problems in that many of the most effective herbicides are either designed to control hardwoods or the product is not labeled for such applications. Numerous studies involving herbicide application in hardwoods have been completed at Mississippi State University. This paper is a compilation of results from...

  10. Solar ultraviolet-B radiation affects seedling emergence, DNA integrity, plant morphology, growth rate, and attractiveness to herbivore insects in Datura ferox

    International Nuclear Information System (INIS)

    Ballare, C.L.; Scopel, A.L.; Stapleton, A.E.

    1996-01-01

    To study functional relationships between the effects of solar ultraviolet-B radiation (UV0B) on different aspects of the physiology of a wild plant, we carried out exclusion experiments in the field with the summer annual Datura ferrox L. Solar UV-B incident over Buenos Aires reduced daytime seedling emergence, inhibited stem elongation and leaf expansion, and tended to reduce biomass accumulation during early growth. However, UV-B had no effect on calculated net assimilation rate. Using a monoclonal antibody specific to the cyclobutane-pyrimidine dimer (CPD), we found that plants receiving full sunlight had more CPDs per unit of DNA than plants shielded from solar UV-B, but the positive correlation between UV-B and CPD burden tended to level off at high (near solar) UV-B levels. At our field site, Datura plants were consumed by leaf beetles (Coleoptera), and the proportion of plants attacked by insects declined with the amount of UV-B received during growth. Field experiments showed that plant exposure to solar UV-B reduced the likelihood of leaf beetle attack by one-half. Our results highlight the complexities associated with scaling plant responses to solar UV-B, because they show: (a) a lack of correspondence between UV-B effects on net assimilation rate and whole-plant growth rate, (b) nonlinear UV-B dose-response curves, and (c) UV-B effects of plant attractiveness to natural herbivores. 56 refs., 7 figs

  11. Nine-year performance of four hardwoods on a harvested site with and without fertilizer tree shelters, and weed mats in southern Illinois

    Science.gov (United States)

    Felix, Jr. Ponder; J.W. Van Sambeek

    2013-01-01

    Quality hardwood species often dominate stands on intermediate to high quality sites before regeneration. However, successfully regenerating these species after the harvest is rarely achieved on these sites. Hardwood species were planted on a high quality site in southern Illinois after clearcutting to study the effect of several cultural practices on the hardwoods...

  12. Microwave irradiation effects on vermicasts potency, and plant growth and antioxidant activity in seedlings of Chinese cabbage (Brassica rapa subsp. pekinensis

    Directory of Open Access Journals (Sweden)

    Lord Abbey

    2017-04-01

    Full Text Available Vermicasts is rich in beneficial microorganisms and plant growth factors. Unlike soils, the effect of microwave irradiation (MWI on vermicasts potency has not been reported. This study investigated MWI effects on vermicasts potency, plant growth and biochemical activity in Chinese cabbage ‘Bilko’ seedlings. Fresh, moist vermicasts were microwaved at power output levels: 0, 100, 200, 300, 400 and 800 Watts (W. Water loss, nutrients and total aerobic plate content were assessed. A complete randomized design greenhouse experiment was used to evaluate seedlings growth performance and tissue bioactivity. Water loss increased from 5 mg/g (0 W to 215 mg/g (800 W. Total dissolved solids and electrical conductivity of the vermicasts gradually increased with an increase in MWI power output level from 0 to 200 W. This was followed by a steep rise through treatment 300 W and a peak at 400 W. Total nitrogen and nitrate decreased, while ammonia-nitrogen and nitrite-nitrogen increased at higher power levels. Similarly, phosphorus, potassium, magnesium, calcium, manganese, barium and molybdenum contents increased while sodium and barium remained fairly constant. However, MWI irradiation reduced total aerobic plate count by ≥50%. Plant growth and biomass were increased by the 400 W and 800 W MWI treatments. Antioxidant activity was highest in 200, 400 and 800 W treated plants. Collectively the finding indicated that the 400 W treatment increased the bioavailability of nutrients, and represents the best option for plant growth enhancement and improved antioxidant activity.

  13. The role of above-ground competition and nitrogen vs. phosphorus enrichment in seedling survival of common European plant species of semi-natural grasslands.

    Directory of Open Access Journals (Sweden)

    Tobias Ceulemans

    Full Text Available Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering competition by reducing grassland productivity through mowing or herbivory can mitigate the environmental impact of nutrient pollution. Furthermore, few studies so far discriminate between nitrogen and phosphorus pollution. We performed a full factorial experiment in greenhouse mesocosms combining nitrogen and phosphorus addition with two clipping regimes designed to relax above-ground competition. Next, we studied the survival and growth of seedlings of eight common European grassland species and found that five out of eight species showed higher survival under the clipping regime with the lowest above-ground competition. Phosphorus addition negatively affected seven plant species and nitrogen addition negatively affected four plant species. Importantly, the negative effects of nutrient addition and higher above-ground competition were independent of each other for all but one species. Our results suggest that at any given level of soil nutrients, relaxation of above-ground competition allows for higher seedling survival in grasslands. At the same time, even at low levels of above-ground competition, nutrient enrichment negatively affects survival as compared to nutrient-poor conditions. Therefore, although maintaining low above-ground competition appears essential for species' recruitment, for instance through mowing or herbivory, these management efforts are likely to be insufficient and we conclude that environmental policies aimed to reduce both excess nitrogen and particularly phosphorus inputs are also necessary.

  14. The potential of beech seedlings to adapt to low P availability in soil - plant versus microbial effects on P mobilising potential in the rhizosphere

    Science.gov (United States)

    Meller, Sonia; Frey, Beat; Frossard, Emmanuel; Spohn, Marie; Schack-Kirchner, Helmer; Luster, Jörg

    2016-04-01

    The objective of our work was to investigate to what extent tree seedlings (Fagus sylvatica) are able to adapt the process of P mobilisation in the rhizosphere according to P speciation in the soil. Such mobilisation activity can include root exudation of P mobilising compounds or stimulation of specific P mobilising soil microbes. We hypothesized that Fagus sylvatica seedlings can adapt their own activity based on their P nutritional status and genetic memory of how to react under a given nutritional situation. To test the hypothesis, we set up a cross-growth experiment with beech of different provenances growing in soil from their own provenance site and in soil differing in P availability. Experiments were performed as a greenhouse experiment, with temperature control and natural light, during one vegetation period in rhizoboxes . We used two acidic forest soils, contrasting in P availability, collected at field sites of the German research priority program "Ecosystem Nutrition". Juvenile trees were collected along with the soils at the sites and planted respectively. The occurrence of P mobilising compounds and available P in the rhizosphere and in bulk soil were measured during the active growth season of the plants. In particular, we assessed phosphatase activity, (measured with zymography and plate enzymatic assay at pH 4,6.5, and 11) carboxylates and phosphate (measured by application of ion exchange membranes to specific soil micro zones, and by microdialysis), and pH (mapping with optodes). Plant P nutrition status was assessed by total P, N/P, phosphatase activity, and metabolic (TCA extractable) P in the leaves. The P-nutritional status of the beech provenances differed markedly independent from the P status of the soil where they were actually grown during experiment. In particular, the juvenile trees from the site rich in mineral P were sufficient in P, while those from the P-poor site with mostly organic P, were deficient. Enzymatic activity at the

  15. Hardwood sawmill downtime costs

    Science.gov (United States)

    Jan Wiedenbeck; Kyle Blackwell

    2003-01-01

    How time flies when you don't pay attention to it. With hardwood sawmill operating costs ranging from $4 to $25 per operating minute ($95/MBF to $335/MBF) and gross profit margins ranging from $0.10/BF to $0.35/BF, five extra minutes of downtime per day will cost a sawmill that produces an average of 20,000 BF per day (5 MMBF annually) between $21 and $73 per day...

  16. Grazing on Regeneration Sites Encourages Pine Seedling Growth

    Science.gov (United States)

    Raymond D. Ratliff; Renee G. Denton

    1995-01-01

    Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the...

  17. Containers of Attalea funifera fibers to produce eucalyptus seedlings

    Directory of Open Access Journals (Sweden)

    Andrea Vita Reis Mendonça

    2016-09-01

    Full Text Available The aim of this study was to assess the technical feasibility of using biodegradable containers made of fiber waste of Attalea funifera Martius to produce seedling of Eucalyptus camaldulensis Dehnh. The work was carried out in three stages: manufacture of piassava fiber containers, seedling production and field simulation. The experiment of seedling production was in completely randomized design, with two treatments (polyethylene tube and biodegradable container and 10 repetitions, with 64 seedlings per repetition. After 93 days, seedlings were evaluated based on quality variables. The simuation of initial growth of seedlings in the field consisted in planting seedlings in containers of 11L, in completely randomized design, with three treatments: seedlings produced in polyethylene tubes; seedlings produced in biodegradable containers, without removal of the container during planting; and seedlings produced in biodegradable containers, with removal of the container at planting, with ten repetitions, with one seedling by repetition. The biodegradable container withstood the production cycle and resulted in seedlings within acceptable standards quality. The use of biodegradable container, made of palm fibers, waived the removal of this vessel in the final planting.

  18. Is Eastern Hardwood Sawtimber Becoming Scarcer?

    Science.gov (United States)

    William G. Luppold; Gilbert P. Dempsey; Gilbert P. Dempsey

    1996-01-01

    In recent years the hardwood lumber industry has become increasingly concerned about the availability and quality of hardwood sawtimber. However, these concerns seem to contradict USDA Forest Service estimates of increased volume and quality of hardwood sawtimber. This paper examines changes in eastern hardwood sawtimber inventories and the apparent contradiction...

  19. Successes and failures in controlling weeds in hardwood seedbeds at the Arkansas Forestry Commission Baucum Forest Nursery

    Science.gov (United States)

    Allan Murray

    2009-01-01

    Fumigation with methyl bromide is essential in the production of hardwood seedlings in nurseries in the southern United States. However, the proposed rules under the 2008 U.S. Environmental Protection Agency (EPA) Risk Mitigation will further restrict the use of methyl bromide for nursery use.

  20. Carbon Nanotubes Filled with Different Ferromagnetic Alloys Affect the Growth and Development of Rice Seedlings by Changing the C:N Ratio and Plant Hormones Concentrations.

    Science.gov (United States)

    Hao, Yi; Yu, Feifan; Lv, Ruitao; Ma, Chuanxin; Zhang, Zetian; Rui, Yukui; Liu, Liming; Cao, Weidong; Xing, Baoshan

    2016-01-01

    The aim of this study was to investigate the phytotoxicity of thin-walled carbon nanotubes (CNTs) to rice (Oryza sativa L.) seedlings. Three different CNTs, including hollow multi-walled carbon nanotubes (MWCNTs), Fe-filled carbon nanotubes (Fe-CNTs), and Fe-Co-filled carbon nanotubes (FeCo-CNTs), were evaluated. The CNTs significantly inhibited rice growth by decreasing the concentrations of endogenous plant hormones. The carbon to nitrogen ratio (C:N ratio) significantly increased in rice roots after treatments with CNTs, and all three types of CNTs had the same effects on the C:N ratio. Interestingly, the increase in the C:N ratio in roots was largely because of decreased N content, indicating that the CNTs significantly decreased N assimilation. Analyses of the Fe and Co contents in plant tissues, transmission electron microscope (TEM) observations and energy dispersive X-ray spectroscopy (EDS) analysis proved that the CNTs could penetrate the cell wall and the cell membrane, and then enter the root cells. According to the author's knowledge, this is the first time to study the relationship between carbon nanotubes and carbon nitrogen ratio and plant hormones.

  1. Short Communication Synergistic effect of rhizobia and plant growth promoting rhizobacteria on the growth and nodulation of lentil seedlings under axenic conditions

    Directory of Open Access Journals (Sweden)

    Muhammad Zafar-ul-Hye

    2013-05-01

    Full Text Available Plant growth promoting rhizobacteria (PGPR containing ACC-deaminase in combination with rhizobia can improve the growth and nodulation in plants by suppressing the endogenous level of ethylene. In the present study, ten strains, each of PGPR and rhizobia from the previously screened cultures were tested for their effect as co-inoculants on growth and nodulation of lentil in growth pouches under axenic conditions. Results showed that most of the combinations improved the lentil growth as compared to the un-inoculated control. Maximum increase in shoot length (1.87 fold, root length (1.97 fold and total biomass (1.98 fold over the un-inoculated control was observed in the treatment where the lentil seedlings were inoculated with the combination Z24P10. Co-inoculation also improved the nodulation in lentil and the maximum number of nodules plant-1 (24 nodules were observed in the combination Z22P10. However, there was no nodulation in few combinations. It is concluded that the co-inoculation with rhizobia and PGPR containing ACC-deaminase has improved the growth and nodulation in lentil under axenic conditions and the selected combinations may be evaluated in pot and field trials

  2. Growing container seedlings: Three considerations

    Science.gov (United States)

    Kas Dumroese; Thomas D. Landis

    2015-01-01

    The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...

  3. Root growth and hydraulic conductivity of southern pine seedlings in response to soil temperature and water availability after planting

    Science.gov (United States)

    Mary Anne Sword Sayer; John C. Brissette; James P. Barnett

    2005-01-01

    Comparison of the root system growth and water transport of southern pine species after planting in different root-zone environments is needed to guide decisions regarding when, and what species to plant. Evaluation of how seed source affects root system responses to soil conditions will allow seed sources to be matched to planting conditions. The root growth and...

  4. Impact of the invasive plant Syzigium jambos (Myrtaceae on patterns of understory seedling abundance in a Tropical Premontane Forest, Costa Rica

    Directory of Open Access Journals (Sweden)

    Gerardo Avalos

    2006-06-01

    Full Text Available Habitat fragmentation, along with other human-induced disturbances, increase the vulnerability of native habitats to be invaded by aggressive, ecologically released, exotic species. Syzigium jambos (L. Alston (Myrtaceae, Rose Apple is an important invader still spreading throughout Hawaii, the Antilles, Central and South America. This study examines the effects of S. jambos on plant understory diversity in a 25 ha Tropical Premontane Moist Forest in Atenas, Alajuela, Costa Rica, a protected watershed that supplies drinking water for several human communities. Our final objective is to develop a management strategy combining water protection with the preservation of a representative sample of the original plant diversity in the area. Thirty 2 X 2 m plots were distributed throughout the Municipal Forest maintaining a minimum of 10 m between plots, and 2 m from trails, to sample all understory seedlings and saplings of S. jambos, Coffea arabica (coffee and tree seedlings. We found a clear dominance of S. jambos over all other understory plants. Of the total 1 285 sampled plants, S. jambos comprised 51%, coffee seedlings represented 14,78%, being the rest tree seedlings. Syzigium jambos had the highest density (5.46 plants/m2, S.D. = 6.44 compared to tree (3.67 plants/ m2, S.D. = 3.44 and coffee seedlings (1.58 plants/ m2, S.D. = 2.13. There was a highly significant negative relationship between the relative abundance of S. jambos and tree (r2 = 0.52, p La fragmentación del hábitat, junto con otros disturbios antropogénicos, aumentan la vulnerabilidad de los ambientes nativos a la invasión por especies exóticas, agresivas y sin controles ecológicos. Syzigium jambos (L. Alston (Myrtaceae, Manzana Rosa es una invasora importante que todavía está extendiendose en Hawaii, Las Antillas, Centro y Suramérica. Este estudio examina los efectos de S. jambos sobre la diversidad de plantas del sotobosque en un Bosque Húmedo Premontano de 25 ha en

  5. Direct detection of the plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae in infected rice seedlings using matrix assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Kajiwara, Hideyuki

    2016-01-01

    The plant pathogens Burkholderia glumae, Burkholderia gladioli pv. gladioli, and Erwinia chrysanthemi pv. zeae were directly detected in extracts from infected rice seedlings by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This method did not require culturing of the pathogens on artificial medium. In the MALDI-TOF MS analysis, peaks originating from bacteria were found in extracts from infected rice seedlings. The spectral peaks showed significantly high scores, in spite of minor differences in spectra. The spectral peaks originating from host plant tissues did not affect this direct MALDI-TOF MS analysis for the rapid identification of plant pathogens. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Synergy of agroforestry and bottomland hardwood afforestation

    Science.gov (United States)

    Twedt, D.J.; Portwood, J.; Clason, Terry R.

    2003-01-01

    Afforestation of bottomland hardwood forests has historically emphasized planting heavy-seeded tree species such as oak (Quercus spp.) and pecan (Caryaillinoensis) with little or no silvicultural management during stand development. Slow growth of these tree species, herbivory, competing vegetation, and limited seed dispersal, often result in restored sites that are slow to develop vertical vegetation structure and have limited tree diversity. Where soils and hydrology permit, agroforestry can provide transitional management that mitigates these historical limitations on converting cropland to forests. Planting short-rotation woody crops and intercropping using wide alleyways are two agroforestry practices that are well suited for transitional management. Weed control associated with agroforestry systems benefits planted trees by reducing competition. The resultant decrease in herbaceous cover suppresses small mammal populations and associated herbivory of trees and seeds. As a result, rapid vertical growth is possible that can 'train' under-planted, slower-growing, species and provide favorable environmental conditions for naturally invading trees. Finally, annual cropping of alleyways or rotational pulpwood harvest of woody crops provides income more rapidly than reliance on future revenue from traditional silviculture. Because of increased forest diversity, enhanced growth and development, and improved economic returns, we believe that using agroforestry as a transitional management strategy during afforestation provides greater benefits to landowners and to the environment than does traditional bottomland hardwood afforestation.

  7. Air lateral root pruning affects longleaf pine seedling root system morphology

    Science.gov (United States)

    Shi-Jean Susana Sung; Dave Haywood

    2016-01-01

    Longleaf pine (Pinus palustris) seedlings were cultured with air lateral root pruning (side-vented containers, VT) or without (solid-walled containers, SW). Seedling root system morphology and growth were assessed before planting and 8 and 14 months after planting. Although VT seedlings had greater root collar diameter than the SW before planting,...

  8. Tree species composition and structure in an old bottomland hardwood forest in south-central Arkansas

    Science.gov (United States)

    Brian Roy Lockhart; James M. Guldin; Thomas Foti

    2010-01-01

    Tree species composition and structure was determined for an old bottomland hardwood forest located in the Moro Creek Bottoms Natural Area in south-central Arkansas. Diversity for this forest was high with species richness ranging from 33 for the overstory and sapling strata to 26 for the seedling stratum and Shannon-Weiner values of 2.54 to 1.02 for the overstory and...

  9. Strip thinning young hardwood forests: multi-functional management for wood, wildlife, and bioenergy

    Science.gov (United States)

    Jamie Schuler; Ashlee Martin

    2016-01-01

    Upland hardwood forests dominate the Appalachian landscape. However, early successional forests are limited. In WV and PA, for example, only 8 percent of the timberland is classified as seedling and sapling-sized. Typically no management occurs in these forests due to the high cost of treatment and the lack of marketable products. If bioenergy markets come to fruition...

  10. Onion seedling production in styrofoam trays under controlled environment, as summer-planted onions Plantas de cebola produzidas em bandejas sob cultivo protegido, no verão

    Directory of Open Access Journals (Sweden)

    Maria Cristina Veiga De Vincenzo

    2003-02-01

    Full Text Available Summer-planted onion (Allium cepa L. can increase grower profits, but the production of seedlings for transplant is difficult. This experiment was carried out in Piracicaba, SP, Brazil, with the objective of studying the behavior of the short-day onion hybrid Mercedes, in its initial stage, under controlled greenhouse environment, as summer-planted onions. Four formulated substrates, two different numbers of plants per cell were tested, and 288-cell styrofoam trays used. Trials were set up in split-plot design (n=3. Substrate and number of plants per cell represented main plots, and N application (2 and 3 times a week the subplots. The number of three plants per cell decrease the earlier onset of bulbing and increase plant height; substrates did not show differences; and the N application 3 times a week increased plant height and leaf dry weight, but did not result in earlier onset of bulbing.Uma das dificuldades do cultivo do verão da cebola (Allium cepa L., que permite maior lucro pois esta é a época de entressafra, é a produção de plantas para o transplante. Com o objetivo de verificar o comportamento na fase de muda do híbrido Mercedes, sob cultivo protegido como cultura de verão, o experimento foi instalado em estufa, em Piracicaba, SP com bandejas de isopor de 288 células. Foram testados quatro substratos. e dois números de plantas por células (3 e 4 plantas/célula, sendo sub-plot a suplementação mineral com nitrogênio 2 e 3 vezes por semana com nitrato de cálcio + nitrato de potássio. O delineamento experimental foi inteiramente casualizado, com fatorial 4 x 2 em parcelas subdivididas, e três repetições. A densidade de três plantas por célula apresentou menor taxa de bulbificação precoce e maior altura da planta; não houve diferença quanto aos substratos e que a aplicação de nitrogênio três vezes por semana apresentou os maiores valores de altura da planta e peso da matéria seca da parte aérea, n

  11. Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer

    Directory of Open Access Journals (Sweden)

    Nicholas Bolton

    2018-03-01

    Full Text Available Emerald ash borer (EAB continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations in depressional black ash wetlands in the Ottawa National Forest in Michigan to mimic the short-term and long-term effects of EAB. These wetlands were planted with 10 alternative tree species in 2013. Based on initial results in the Michigan sites, a riparian corridor in the Superior Municipal Forest in Wisconsin was planted with three alternative tree species in 2015. Results across both locations indicate that silver maple (Acer saccharinum L., red maple (Acer rubrum L., American elm (Ulmus americana L., and northern white cedar (Thuja occidentalis L. are viable alternative species to plant in black ash-dominated wetlands. Additionally, selectively planting on natural or created hummocks resulted in two times greater survival than in adjacent lowland sites, and this suggests that planting should be implemented with microsite selection or creation as a primary control. Regional landowners and forest managers can use these results to help mitigate the canopy and structure losses from EAB and maintain forest cover and hydrologic function in black ash-dominated wetlands after infestation.

  12. 1997 Hardwood Research Award Winner: "Automatic Color Sorting of Hardwood Edge-Glued Panel Parts"

    Science.gov (United States)

    D. Earl Kline; Richard Conners; Qiang Lu; Philip A. Araman

    1997-01-01

    The National Hardwood Lumber Association's 1997 Hardwood Research Award was presented to D. Earl Kline, Richard Conners, Qiang Lu and Philip Araman at the 25th Annual Hardwood Symposium for developing an automatic system for color sorting hardwood edge-glued panel parts. The researchers comprise a team from Virginia Tech University and the USDA Forest Service in...

  13. Seedling root targets

    Science.gov (United States)

    Diane L. Haase

    2011-01-01

    Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...

  14. A theoretical framework for whole-plant carbon assimilation efficiency based on metabolic scaling theory: a test case using Picea seedlings.

    Science.gov (United States)

    Wang, Zhiqiang; Ji, Mingfei; Deng, Jianming; Milne, Richard I; Ran, Jinzhi; Zhang, Qiang; Fan, Zhexuan; Zhang, Xiaowei; Li, Jiangtao; Huang, Heng; Cheng, Dongliang; Niklas, Karl J

    2015-06-01

    Simultaneous and accurate measurements of whole-plant instantaneous carbon-use efficiency (ICUE) and annual total carbon-use efficiency (TCUE) are difficult to make, especially for trees. One usually estimates ICUE based on the net photosynthetic rate or the assumed proportional relationship between growth efficiency and ICUE. However, thus far, protocols for easily estimating annual TCUE remain problematic. Here, we present a theoretical framework (based on the metabolic scaling theory) to predict whole-plant annual TCUE by directly measuring instantaneous net photosynthetic and respiratory rates. This framework makes four predictions, which were evaluated empirically using seedlings of nine Picea taxa: (i) the flux rates of CO(2) and energy will scale isometrically as a function of plant size, (ii) whole-plant net and gross photosynthetic rates and the net primary productivity will scale isometrically with respect to total leaf mass, (iii) these scaling relationships will be independent of ambient temperature and humidity fluctuations (as measured within an experimental chamber) regardless of the instantaneous net photosynthetic rate or dark respiratory rate, or overall growth rate and (iv) TCUE will scale isometrically with respect to instantaneous efficiency of carbon use (i.e., the latter can be used to predict the former) across diverse species. These predictions were experimentally verified. We also found that the ranking of the nine taxa based on net photosynthetic rates differed from ranking based on either ICUE or TCUE. In addition, the absolute values of ICUE and TCUE significantly differed among the nine taxa, with both ICUE and temperature-corrected ICUE being highest for Picea abies and lowest for Picea schrenkiana. Nevertheless, the data are consistent with the predictions of our general theoretical framework, which can be used to access annual carbon-use efficiency of different species at the level of an individual plant based on simple, direct

  15. Harvesting costs and utilization of hardwood plantations

    Science.gov (United States)

    Tim P. McDonald; Bryce J. Stokes

    1994-01-01

    The use of short rotation, intensive culture (SRIC) practices in hardwoods to meet fiber supply needs is becoming increasingly widespread. Total plated area of short rotation hardwood fiber plantations is currently about 22,000 ha (McDonald and Stokes 1993). That figure should certainly to grow in response to public concerns over loss of natural hardwood stands. With...

  16. Conifers, angiosperm trees, and lianas: growth, whole-plant water and nitrogen use efficiency, and stable isotope composition ({delta}13C and {delta}18O) of seedlings grown in a tropical environment.

    Science.gov (United States)

    Cernusak, Lucas A; Winter, Klaus; Aranda, Jorge; Turner, Benjamin L

    2008-09-01

    Seedlings of several species of gymnosperm trees, angiosperm trees, and angiosperm lianas were grown under tropical field conditions in the Republic of Panama; physiological processes controlling plant C and water fluxes were assessed across this functionally diverse range of species. Relative growth rate, r, was primarily controlled by the ratio of leaf area to plant mass, of which specific leaf area was a key component. Instantaneous photosynthesis, when expressed on a leaf-mass basis, explained 69% of variation in r (P physiological models of tropical forest trees.

  17. Proteomics and Transcriptomics analysis of Arabidopsis Seedlings in Microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — On Earth plants are constantly exposed to a gravitational field of 1g. Gravity affects a plant in every step of its development. Germinating seedlings orient their...

  18. Effect of ethephon on hardening of Pachystroma longifolium seedlings

    Directory of Open Access Journals (Sweden)

    João Alexandre Lopes Dranski

    2013-06-01

    Full Text Available Immediately after planting, tree seedlings face adverse environmental and biotic stresses that must be overcome to ensure survival and to yield a desirable growth. Hardening practices in the nursery may help improve seedling stress resistance through reduction of aboveground plant tissues and increased root volume and biomass. We conducted an assay to quantify changes in the morphogenesis following application of ethephon on seedlings of Pachystroma longifolium (Ness I. M. Johnst.during hardening. The results showed no effect of the ethephon treatments on the number of leaves but a reduction of up to 50% in seedling height increment, and an increase in stem diameter increment of up to 44% with the 600 mg L-1 ethephon treatment, which consequently altered seedling Dickson Quality Index. Our results indicate that ethephon may help to promote desired morphological changes that occur during seedling hardening in nurseries.

  19. Direct-seedling pines in the south

    Science.gov (United States)

    Harold J. Derr; William F. Mann

    1971-01-01

    Direct seeding of the southern pines is a versatile reforestation technique that is being widely accepted by land managers. On many sites it is more economical than planting nursery-grown seedlings or waiting for natural reproduction. It is applicable on some sites where access, terrain, or drainage conditions make planting difficult. Commercial trials have proved it...

  20. Drying hardwood lumber

    Energy Technology Data Exchange (ETDEWEB)

    Chow, A T

    1988-11-14

    Dried lumber is a high-value-added product, especially when it is of high quality. Lumber damaged during the drying operation can represent substantial lost revenue. It has been demonstrated that dehumidification kilns can improve lumber quality, and reduce energy consumption over conventional drying methods. A summary of the literature on drying hardwood lumber, particularly using heat pump dehumidification, has been prepared to allow the information to be readily accessible to Ontario Hydro personnel who work with customers in the lumber industry. For that purpose, this summary has been prepared from the perspective of the customer, a dry kiln operator. Included are brief descriptions of drying schedules, precautions needed to minimize drying defects in the lumber, and rules-of-thumb for selecting and estimating the capital cost of the drying equipment. A selection of drying schedules and moisture contents of green lumber, a glossary of lumber defects and brief descriptions of the possible preventive measures are also included. 10 refs., 8 figs., 4 tabs.

  1. Effects of Mechanical Site Preparation on Growth of Oaks Planted on Former Agricultural Fields

    Directory of Open Access Journals (Sweden)

    John D. Hodges

    2011-12-01

    Full Text Available Mechanical site preparation is frequently proposed to alleviate problematic soil conditions when afforesting retired agricultural fields. Without management of soil problems, any seedlings planted in these areas may exhibit poor growth and survival. While mechanical site preparation methods currently employed in hardwood afforestation are proven, there is a substantial void in research comparing subsoiling, bedding, and combination plowing treatments. A total of 4,320 bare-root Nuttall oak (Quercus texana Buckley, Shumard oak (Quercus shumardii Buckley, and swamp chestnut oak (Quercus michauxii Nutt. seedlings were planted in February 2008 on three Mississippi sites. All sites were of comparable soils and received above average precipitation throughout the three-year duration of the study. Four site preparation treatments were replicated at each site, with 480 seedlings planted in each of nine replications, and a total of 1,440 seedlings per species planted across all sites. Mechanical treatments were installed using 3.1 m row centers, with treatments as follows: control, subsoiling, bedding, and combination plowing. Treatment effects on seedling height, groundline diameter (GLD, and survival were analyzed. Seedlings exhibited greater height in bedded and combination plowed areas (79.7 cm to 102.7 cm and 82.6 cm to 100.1 cm, respectively compared to subsoiled or control areas (70.4 cm to 84.6 cm and 71.4 cm to 86.9 cm, respectively. Greater GLD was observed in bedded and combination plowed areas (11.9 mm to 18.4 mm and 12.2 mm to 18.3 mm, respectively compared to subsoiled or control areas (10.2 mm to 14.6 mm and 10.5 mm to 15.6 mm, respectively. Survival was high for this study (94.%, and no differences were detected among treatments.

  2. Short-Term Response of Native Flora to the Removal of Non-Native Shrubs in Mixed-Hardwood Forests of Indiana, USA

    Directory of Open Access Journals (Sweden)

    Joshua M. Shields

    2015-05-01

    Full Text Available While negative impacts of invasive species on native communities are well documented, less is known about how these communities respond to the removal of established populations of invasive species. With regard to invasive shrubs, studies examining native community response to removal at scales greater than experimental plots are lacking. We examined short-term effects of removing Lonicera maackii (Amur honeysuckle and other non-native shrubs on native plant taxa in six mixed-hardwood forests. Each study site contained two 0.64 ha sample areas—an area where all non-native shrubs were removed and a reference area where no treatment was implemented. We sampled vegetation in the spring and summer before and after non-native shrubs were removed. Cover and diversity of native species, and densities of native woody seedlings, increased after shrub removal. However, we also observed significant increases in L. maackii seedling densities and Alliaria petiolata (garlic mustard cover in removal areas. Changes in reference areas were less pronounced and mostly non-significant. Our results suggest that removing non-native shrubs allows short-term recovery of native communities across a range of invasion intensities. However, successful restoration will likely depend on renewed competition with invasive species that re-colonize treatment areas, the influence of herbivores, and subsequent control efforts.

  3. Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

    International Nuclear Information System (INIS)

    Nelson, E.A.

    2000-01-01

    thickets that support a lower diversity of wildlife. No volunteer seedlings of heavy-seeded hardwoods or cypress have been found in the corridor areas. Research was conducted to determine methods to reintroduce tree species characteristic of more mature forested wetlands. Three restoration strategies were formulated to deal with the differing conditions of the Upper Corridor, the Lower Corridor, and the Delta regions of the impacted area. Site preparation and planting of each area with mixtures of tree species were carried out to speed the restoration of the ecosystem. Species composition and selection were altered based on the current and expected hydrological regimes that the reforestation areas will be experiencing. Because of the operational design of the restoration project, a research program naturally followed to document the success. Many of those efforts are detailed here

  4. An Examination of Regional Hardwood Roundwood Markets in West Virginia

    Science.gov (United States)

    William Luppold; Delton Alderman; Delton Alderman

    2005-01-01

    West Virginia?s hardwood resource is large and diverse ranging from oak-hickory forests in the southern and western portions of the state to northern hardwood stands in the northeastern region. West Virginia also has a diverse group of primary hardwood- processing industries, including hardwood grade mills, industrial hardwood sawmills, engineered wood-product...

  5. Strategic plans for the Hardwood Tree Improvement and Regeneration Center

    Science.gov (United States)

    Charles H. Michler; Keith E. Woeste

    2002-01-01

    The mission of the Hardwood Tree Improvement and Regeneration Center (HTIRC) at Purdue University is to advance the science of hardwood tree improvement and genomics in the central hardwood region of the United States by: developing and disseminating knowledge on improving the genetic quality of hardwood tree species; conserving fine hardwood germplasm; developing...

  6. First-year growth for two oak species and three planting stocks planted on areas disturbed by Hurricane Katrina

    Science.gov (United States)

    Andrew Dowdy; Andrew W. Ezell; Emily B. Schultz; John D. Hodges; Andrew B. Self

    2014-01-01

    Bottomland hardwood forests were damaged by Hurricane Katrina in 2005 when it made landfall along the Gulf Coast. Regenerating these areas, which can be difficult without planning and artificial regeneration, has often been problematic when using 1-0 bare-root seedlings because of inconsistencies with the seedling quality. Some growers have begun producing...

  7. Uptake pathways of fluorescent indicators by pea seed and seedlings and their potential as anti-counterfeiting labeling for plant seeds

    International Nuclear Information System (INIS)

    Lin, C.; Guan, Y. J.; Fu, H.; Hu, J.; Tian, Y. X.

    2015-01-01

    The present study investigates the effects of seed soaking in varying concentration of rhodamine B (RB) or safranine T (ST) solutions on germination and seedling growth of pea seeds. The fluorescence in pea seedling at different developmental stages was observed. The results indicate that there were no adverse effects of seed soaking in RB (0.1mg/ml) and ST (0.5, 0.3, 0.1mg/ml) solutions on germination, seedling growth, antioxidant enzyme activities, malondialdehyde (MDA) and chlorophyll contents. The seeds treated with RB showed bright red and orange fluorescence under green (546 nm) and blue (495 nm) light excitation, respectively while no red or orange color was observed in the control seeds. In addition, the vascular bundles of stem, seedling roots and aerial parts of seedlings treated with RB all emitted brilliant fluorescence for a longer time as compared with that treated with ST. It can be concluded that pea seed labeled with RB by seed soaking at appropriate concentration could be used as a potential anti-counterfeiting technique in pea seeds. (author)

  8. Avaliação qualitativa de mudas destinadas à arborização urbana no Estado de Minas Gerais Qualitative evaluation of tree seedlings destined for urban planting in the State of Minas Gerais

    Directory of Open Access Journals (Sweden)

    Elzimar de Oliveira Gonçalves

    2004-08-01

    Full Text Available Este estudo, realizado em diversos viveiros do Estado de Minas Gerais, objetivou avaliar a qualidade das mudas destinadas à arborização urbana. A avaliação foi feita através de visitas a 12 viveiros no estado, sendo seis de instituições públicas e seis de particulares. Os resultados indicaram que, de maneira geral, não há uma preocupação com a qualidade das mudas, fato comprovado pelas altas porcentagens daquelas fora do padrão. Somente as injúrias mecânicas e as raízes expostas estavam com baixas porcentagens fora do ideal. Os problemas que mais contribuem para a baixa qualidade das mudas, tanto em viveiros públicos quanto particulares, são a altura abaixo da recomendada e a ausência de podas de condução e de formação. Portanto, os primeiros esforços para a melhoria da qualidade devem ser sobre essas características. A análise indicou ainda que grande parte dos problemas se deve à falta de treinamento dos funcionários e domínio das técnicas silviculturais necessárias à produção das mudas, principalmente em se tratando de viveiros particulares, onde as mudas estão com qualidade inferior às dos viveiros públicos.This study was carried out in nurseries in the State of Minas Gerais to evaluate the quality of tree seedlings destined to urban areas. Twelve nurseries were evaluated; half of them run by public institutions and the other half were private nurseries. The results showed that, in general, there is not a concern with quality of seedling, which is proven by the high percentages of low quality seedlings. Only plants with mechanical injuries and exposed roots had low off standard percentages. In both public and private nurseries, the problems that most contributed for low quality seedlings are height bellow recommended and lack of pruning for tree conduction and formation. Therefore, efforts for quality improvement must first be put on these characteristics. Furthermore, the analyses showed that the

  9. Eastern Redcedar Seedling Assessment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Eastern redcedar tree seedling growth in response to various soil, nitrogen, and photosynthetic radiation characteristics. This dataset is associated with the...

  10. Marketing Hardwoods to Furniture Producers

    Science.gov (United States)

    Steven A. Sinclair; Robert J. Bush; Philip A. Araman

    1989-01-01

    This paper discusses some of the many problems in developing marketing programs for small wood products manufacturers. It examines the problems of using price as a dominant means for getting and attracting customers. The marketing of hardwood lumber to furniture producers is then used as an example. Data from 36 furniture lumber buyers is presented to illustrate...

  11. Bottomland Hardwood Ecosystem Management Project

    Science.gov (United States)

    John A. Stanturf; Calvin E. Meier

    1994-01-01

    Federal agency approaches to land management are undergoing a shift from parcel-specific concerns toward a more holistic, ecosystem management approach. Southern bottomland hardwood ecosystems provide important environmental services and commodity goods (Wharton et al. 1982), yet much of our knowledge of these systems comes from anecdotal information. The Bottomland...

  12. Anthracnose Diseases of Eastern Hardwoods

    Science.gov (United States)

    Frederick H. Berry

    1985-01-01

    Anthracnose diseases of hardwood trees are widespread throughout the Eastern United States. The most common symptom of these diseases is dead areas or blotches on the leaves. Because of the brown and black, scorched appearance of the leaves, the diseases are sometimes called leaf blight.

  13. Soil Management for Hardwood Production

    Science.gov (United States)

    W. M. Broadfoot; B. G. Blackmon; J. B. Baker

    1971-01-01

    Soil management is the key to successful hardwood management because soil properties are probably the most important determinants of forest productivity. Because of the lack of soil uniformity, however, many foresters have become frustrated with attempts to relate soil to satisfactory growth. Since soil scientists have been unable to predict site quality for trees in...

  14. Facilitating Oak and Hickory Regeneration in Mature Central Hardwood Forests

    Directory of Open Access Journals (Sweden)

    Eric J. Holzmueller

    2014-12-01

    Full Text Available Advanced oak and hickory regeneration is often absent in mature oak-hickory forests in the Central Hardwood Region of the United States. Prescribed fire and thinning, alone and combined, are commonly prescribed silvicultural treatments that are recommended to initiate the regeneration process. This study examined the regeneration response in three mature oak stands following four treatments: (1 thin, (2 burn, (3 thinning and burning, or (4 no treatment (control. Ten years after initial treatment, results indicate that oak and hickory seedlings had greater height and diameter in the thinning and burning treatment compared to the control and that this treatment may help facilitate desirable regeneration in mature oak-hickory forests.

  15. Abundance and Size Distribution of Cavity Trees in Second-Growth and Old-Growth Central Hardwood Forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson III; David R. Larsen

    2005-01-01

    In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

  16. Abundance and size distribution of cavity trees in second-growth and old-growth central hardwood forests

    Science.gov (United States)

    Zhaofei Fan; Stephen R. Shifley; Martin A. Spetich; Frank R. Thompson; David R. Larsen

    2005-01-01

    In central hardwood forests, mean cavity-tree abundance increases with increasing standsize class (seedling/sapling, pole, sawtimber, old-growth). However, within a size class, the number of cavity trees is highly variable among 0.1-ha inventory plots. Plots in young stands are most likely to have no cavity trees, but some plots may have more than 50 cavity trees/ha....

  17. Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on ...

    African Journals Online (AJOL)

    Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on Plant Species Recovery in Kondoa Irangi Hills, Tanzania. ... There were high significant correlations of 0.85 and 0.87 between seedling recruitment and mortality in both sites, indicating that other factors, probably aridity, rather than prevailing site conditions ...

  18. Twenty-nine years of development in planted cherrybark oak-sweetgum mixtures: implications for future mixed-species hardwood plantations

    Science.gov (United States)

    Brian Roy Lockhart; Andrew W. Ezell; John D. Hodges; Wayne K. Clatterbuck

    2012-01-01

    Results from a long-term planted mixture of cherrybark oak (Quercus pagoda Raf.) and sweetgum (Liquidambar styraciflua L.) showed sweetgum taller in height and larger in diameter than cherrybark oak early in plantation development. By age 17, cherrybark oak was similar in height and diameter with sweetgum and by age 21 was taller...

  19. Effect of seedling stock on the early stand development and physiology of improved loblolly pine (Pinus taeda L.) seedlings

    Science.gov (United States)

    Shakuntala Sharma; Joshua P. Adams; Jamie L. Schuler; Robert L. Ficklin; Don C. Bragg

    2016-01-01

    This study assessed the effects of spacing and genotype on the growth and physiology of improved loblolly pine (Pinus taeda L.) seedlings from three distinct genotypes planted in Drew County, Arkansas (USA). Genotype had a significant effect on survival and height. Clone CF Var 1 showed greater height and survival compared to other seedlings....

  20. The effects of seed ingestion by livestock, dung fertilization, trampling, grass competition and fire on seedling establishment of two woody plant species

    CSIR Research Space (South Africa)

    Tjelele, J

    2015-02-01

    Full Text Available the objectives of an agricultural enterprise. The objectives of this study were to determine the effects of gut passage (goats, cattle), dung (nutrients), fire, grass competition and trampling on establishment of A. nilotica and D. cinerea seedlings. Germination...

  1. Effects of ionizing-radiation and post-radiation action of some plant growth regulators on the seed germination and seedling growth of Scotch pine

    Directory of Open Access Journals (Sweden)

    Leszek Michalski

    2015-01-01

    Full Text Available The effects of small doses of gamma irradiation on the seed germination and seedling growth of Scotch pine and post-radiation action of water solutions of IAA, GA3 and kinetin have been investigated. Changes in the destructive action of ionizing-radiation toy gibberellic acid and its intensifying by IAA and kinetin has been found.

  2. The Hardwood Tree Improvement and Regeneration Center: its strategic plans for sustaining the hardwood resource

    Science.gov (United States)

    Charles H. Michler; Michael J. Bosela; Paula M. Pijut; Keith E. Woeste

    2003-01-01

    A regional center for hardwood tree improvement, genomics, and regeneration research, development and technology transfer will focus on black walnut, black cherry, northern red oak and, in the future, on other fine hardwoods as the effort is expanded. The Hardwood Tree Improvement and Regeneration Center (HTIRC) will use molecular genetics and genomics along with...

  3. Utilization of the Eastern Hardwood Resource by the Hardwood Sawmilling Industry

    Science.gov (United States)

    William Luppold; John Baumgras; John Baumgras

    2001-01-01

    The eastern hardwood resource contains numerous species that differ in grain, color, texture, and workability. Because the value of hardwoods is derived from appearance, these variations in physical attributes can cause the price for identical grades of hardwood lumber to vary by as much as 600% between species. As a result, there is incentive for primary processors to...

  4. The state of hardwood lumber markets

    Science.gov (United States)

    Gilbert P. Dempsey; William G. Luppold

    1992-01-01

    Although the 1990-91 recession has temporarily dampened the demand for hardwood lumber, the decade of the 1980s was a period of strong growth in the hardwood market. After experiencing a flat market in 1980 and a decline in 1982, the demand for hardwood lumber by both the domestic industry and the export market increased strongly—from 8 billion board feet in 1982 to 11...

  5. Encroachment Dynamics of Juniperus virginiana L. and Mesic Hardwood Species into Cross Timbers Forests of North-Central Oklahoma, USA

    Directory of Open Access Journals (Sweden)

    Daniel L. Hoff

    2018-02-01

    Full Text Available Cross Timbers forests, typically dominated by Quercus stellata Wangenh. and Q. marilandica Muenchh., are the transition zone between eastern deciduous forest and prairie in the southern Great Plains. Fire exclusion beginning in the mid-1900s has led to increasing stand density and encroachment of fire-intolerant Juniperus virginiana L. and mesic hardwood. We measured current forest structure and tree ages of 25 stands (130 plots in north-central Oklahoma to characterize the extent and dynamics of encroachment. The respective basal area and stand density of the overstory (diameter at breast height; dbh > 10 cm were 19.0 m2 ha−1 and 407 trees ha−1 with Q. stellata comprising 43% of basal area and 42% of stand density. Quercus marilandica represented only 3% of basal area and 4% of overstory density. Juniperus virginiana represented 7% of basal area and 14% of stand density while mesic hardwoods, e.g., Celtis spp., Ulmus spp., Carya spp., 33% of basal area and stand density. The sapling layer was dominated by mesic hardwoods (68% and J. virginiana (25% while the seedling layer was dominated by mesic hardwoods (74%. The majority of Quercus recruited into the overstory between 1910–1970, while recruitment of J. virginiana and mesic hardwoods began more recently (post 1950s. Growth rate, based on the relationship between age and dbh, was faster for mesic hardwoods than for J. virginiana and Q. stellata. These results indicate that removal of recurrent surface fire as a disturbance agent has significantly altered forest composition in the Cross Timbers region by allowing encroachment of J. virginiana and fire-intolerant, mesic hardwoods. This increases wildfire risk because J. virginiana is very flammable and will alter how these forests respond to future drought and other disturbance events.

  6. Cold stratification, but not stratification in salinity, enhances seedling ...

    African Journals Online (AJOL)

    use

    2011-10-26

    Oct 26, 2011 ... Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. ... Key words: Cold stratification, salt stress, seedling emergence, ... methods used to cope with salinity, seed pre-sowing.

  7. Re-use of seedling containers and Fusarium circinatum association ...

    African Journals Online (AJOL)

    Re-use of seedling containers and Fusarium circinatum association with asymptomatic Pinus patula planting stock. Andrew R Morris, Gerda Fourie, Izette Greyling, Emma T Steenkamp, Nicoletta B Jones ...

  8. The Relationship Between Soils and Foliar Nutrition For Planted Royal Paulownia

    Science.gov (United States)

    James E. Johnson; David O. Mitchem; Richard E. Kreh

    2002-01-01

    Royal paulownia is becoming an important hardwood plantation species in the southern U.S. A study was done to investigate two novel site preparation techniques for aiding the establishment of royal paulownia seedlings in the Virginia Piedmont. The effects of these treatments on the foliar nutrition of first year seedlings was determined, as was the relationship...

  9. RESULTS ON THE EFFECT OF DIFFERENT TYPES OF ROMANIAN NATIVE PEAT BIO COMPOSITES POTS ON SEEDLING GROWTH

    OpenAIRE

    Florina Uleanu

    2013-01-01

    Seedlings production is an important link in vegetable culture because many vegetables species are grown by producing prior of seedlings. The theme work is in line with Western trends to produce seedlings by integrating new vegetables technologies, profitable, with positive effect on limiting pathogens to obtain seedlings, using biodegradable pots. Were conducted various observations and measurements on plants when they have reached the optimum phase for planting. We have determined: height o...

  10. The effects of Vexar® seedling protectors on the growth and development of lodgepole pine roots

    Science.gov (United States)

    Engeman, Richard M.; Anthony, R. Michael; Krupa, Heather W.; Evans, James

    1997-01-01

    The effects on the growth and development of lodgepole pine roots from the Vexar® tubes used to protect seedlings from pocket gopher damage were studied in the Targhee National Forest, Idaho and the Deschutes National Forest, Oregon. At each site, Vexar-protected and unprotected seedlings, with and without above-ground gopher damage were examined after six growing seasons for root deformities and growth. Undamaged seedlings exhibited greater growth, reflecting the importance of non-lethal gopher damage as a deterrent to tree growth. Protected seedlings with similar damage history as unprotected seedlings had greater root depth than unprotected seedlings, although unprotected seedlings with no above-ground damage generally had the greatest root weight. In general, the percent of seedlings with root deformities was greater for the unprotected seedlings than for the Vexar-protectd seedlings, although this could be largely due to the greater care required to plant protected seedlings. Acute deformities were more common for unprotected seedlings, whereas root deformities with less severe bending were more common for protected seedlings. The incidence of crossed roots was similar for protected and unprotected seedlings on the Deschutes site, where enough occurrences of this deformity permitted analyses. Protected seedlings were similar in root abundance, root distribution, root size and vigor to the unprotected seedlings, with some indication from the Deshutes study site that root distribution was improved with Vexar protection.

  11. Hardwood supply in the Pacific Northwest-a policy perspective.

    Science.gov (United States)

    Terry L. Raettig; Kent P. Connaughton; Glenn R. Ahrens

    1995-01-01

    The policy framework for the hardwood resource and hardwood industry in western Oregon and Washington is examined. Harvesting trends, harvesting behavior of public and private landowners, and harvesting regulation are presented to complete the analysis of factors affecting short-run hardwood supply. In the short term, the supply of hardwoods is generally favorable, but...

  12. Low-grade hardwood lumber production, markets, and issues

    Science.gov (United States)

    Dan Cumbo; Robert Smith; Philip A. Araman

    2003-01-01

    Due to recent downturn in the economy and changes in traditional hardwood markets. U.S. hardwood manufacturers are facing significant difficulties. In particular, markets for low-grade lumber have been diminishing, while increased levels of the material are being produced at hardwood sawmills in the United States. A nationwide survey of hardwood lumber manufacturers...

  13. Gluing of Eastern Hardwoods: A Review

    Science.gov (United States)

    Terry Sellers; James R. McSween; William T. Nearn

    1988-01-01

    Over a period of years, inrreasing demand for softwoods in the Eastern United States has led to an increase in the growth of hardwoods on cut-over softwood sites. Unfortunately these hardwood trees are often of a size and shape unsuitable for the production of high-grade lumber and veneer. They do, however, represent a viable, economic soures of raw material for...

  14. Automatic Edging and Trimming of Hardwood Lumber

    Science.gov (United States)

    D. Earl Kline; Eugene M. Wengert; Philip A. Araman

    1990-01-01

    Studies have shown that there is a potential to increase hardwood lumber value by more than 20 percent through optimum edging and trimming. Even a small portion of this percentage can boost the profitability of hardwood lumber manufacturers substantially. The objective of this research project is to develop an automated system which would assist in correct edging and...

  15. 77 FR 71017 - Hardwood Plywood From China

    Science.gov (United States)

    2012-11-28

    ...)] Hardwood Plywood From China Determinations On the basis of the record \\1\\ developed in the subject... plywood from China that are allegedly subsidized and sold in the United States at less than fair value... and subsidized imports of hardwood plywood from China. Accordingly, effective September 27, 2012, the...

  16. Sources of the Indiana hardwood industry's competitiveness

    Science.gov (United States)

    Silas Tora; Eva Haviarova

    2008-01-01

    The estimated 1,600 forest products-related firms in Indiana employ more than 56,000 workers. Hardwood manufacturers are the largest segment, adding approximately $2 billion per year of raw product value. A recent report by BioCrossroads ranked the hardwood industry as the most important in the agricultural sector in Indiana. Like most of the other forest products...

  17. The pallet industry: a changing hardwood market

    Science.gov (United States)

    G.P. Dempsey; D.G. Martens

    1991-01-01

    From its inception during World War II, the wooden pallet industry has grown to become the Nation's largest industrial consumer of hardwood lumber products. Since most of the raw material in wooden pallets is lower grade lumber, the pallet industry's growth, efficiency, and changing raw material inputs must be of concern to the grade hardwood lumber industry...

  18. Analysis on Factors Affecting Seedling Establishment in Rice

    Directory of Open Access Journals (Sweden)

    Ju LUO

    2007-03-01

    Full Text Available Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production. Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl (long, medium and short were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions. The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations, and two semi-dwarf varieties (G140, Zhong 96–21 with good seedling establishments and optimum mesocotyl lengths were found. The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl, coleoptile, seeding depth, flooding duration, and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl, coleoptile, mesocotyl × coleoptile, seeding depth, flooding duration and mesocotyl × sowing depth in the experiment for seedling establishment.

  19. Responses of endogenous proline in rice seedlings under chromium exposure

    Directory of Open Access Journals (Sweden)

    X.Z. Yu

    2016-12-01

    Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p

  20. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L.

    Science.gov (United States)

    Ortmans, William; Mahy, Grégory; Monty, Arnaud

    2016-02-01

    Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

  1. Estabelecimento de plântulas e desempenho de plantas em resposta ao vigor dos aquênios de girassol Seedlings establishment and plants performance as affected by sunflower achenes vigour

    Directory of Open Access Journals (Sweden)

    Madelon Rodrigues Sá Braz

    2009-10-01

    Full Text Available O vigor das sementes pode influenciar o estabelecimento e o desempenho das plantas, mas o efeito na produção dessas plantas, principalmente, de cultivo anual, cuja colheita é feita na fase reprodutiva, não está completamente esclarecido. O objetivo do trabalho foi avaliar a influência da qualidade fisiológica de aquênios de girassol no estabelecimento das plântulas e no desempenho das plantas. Para tanto, foi instalado um experimento em campo, com três lotes de aquênios de girassol da cultivar 'Embrapa 122 V2000', com distintos níveis de vigor. A população de plantas foi avaliada aos 10, 20, 40, 60, 80 e 100 dias após a semeadura (DAS. Aos 20, 40, 60, 80 e 100DAS, em intervalo de 20 dias, foram avaliados a altura da planta, o número de folhas, o diâmetro de caule e a massa de matéria seca de parte aérea e total. Também aos 100DAS foram avaliados o número de aquênios por planta, a massa de 1000 aquênios, a produção de aquênios (g planta-1 e o rendimento (kg ha-1. Após dois e seis meses da colheita, os aquênios foram submetidos aos testes de germinação, de primeira contagem, de envelhecimento acelerado, de emergência de plântulas em areia, de comprimento de plântula e de condutividade elétrica. Os resultados permitiram concluir que houve efeito favorável do vigor dos aquênios na população de plantas até os 60DAS. A utilização de aquênios vigorosos de girassol favoreceu o desenvolvimento das plantas após 60DAS, e esse efeito persistiu até a produção, na ausência de diferença na população inicial.Seed vigour may influence the establishment and growth of plants. However, the effect on plants production mostly annual crop, which harvesting is done in the reproductive phase, is not clear. The aim of this research was to evaluate the influence of sunflower achenes physiological quality on the seedlings establishment and plant performance. An experiment was installed in the field, with three lots of

  2. Control of decay in bolts and logs of northern hardwoods during storage

    Science.gov (United States)

    Theodore C. Scheffer; T. W. Jones

    1953-01-01

    Many wood-using plants in the Northeast store large quantities of hardwood logs for rather long periods. Sometimes a large volume of the wood is spoiled by decay during the storage period. A number of people have asked: "How can we prevent this loss?"

  3. Growth and Survival of Hardwoods and Pine Interplanted with European Alder

    Science.gov (United States)

    William T. Plass

    1977-01-01

    European black alder is recommended for planting on many surface mine spoils in the eastern United States. It grows rapidly on a range of spoil types and contributes to soil enrichment by fixing nitrogen and providing a leaf fall rich in nutrients. This study evaluated the effect of alder on the survival and growth of five hardwood and five pine species. After 10...

  4. In vitro propagation of tropical hardwood tree species — A review (2001-2011)

    Science.gov (United States)

    Paula M. Pijut; Rochelle R. Beasley; Shaneka S. Lawson; Kaitlin J. Palla; Micah E. Stevens; Ying. Wang

    2012-01-01

    Tropical hardwood tree species are important economically and ecologically, and play a significant role in the biodiversity of plant and animal species within an ecosystem. There are over 600 species of tropical timbers in the world, many of which are commercially valuable in the international trade of plywood, roundwood, sawnwood, and veneer. Many of these tree...

  5. 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...

  6. Avian response to bottomland hardwood reforestation: the first 10 years

    Science.gov (United States)

    Twedt, D.J.; Wilson, R.R.; Henne-Kerr, J.L.; Grosshuesch, D.A.

    2002-01-01

    Bttomland hardwood forests were planted on agricultural fields in Mississippi and Louisiana using either predominantly Quercus species (oaks) or Populus deltoides (eastern cottonwood). We assessed avian colonization of these reforested sites between 2 and 10 years after planting. Rapid vertical growth of cottonwoods (circa 2 - 3 m / yr) resulted in sites with forest structure that supported greater species richness of breeding birds, increased Shannon diversity indices, and supported greater territory densities than on sites planted with slower-growing oak species. Grassland birds (Spiza americana [Dickcissel], and Sturnella magna [Eastern Meadowlark]) were indicative of species breeding on oak-dominated reforestation # 10 years old. Agelaius phoeniceus (Red-winged Blackbird) and Colinus virginianus (Northern Bobwhite) characterized cottonwood reforestation # 4 years old, whereas 14 species of shrub-scrub birds (e.g., Passerina cyanea [Indigo Bunting]) and early-successional forest birds (e.g., Vireo gilvus [Warbling Vireo]) typified cottonwood reforestation 5 to 9 years after planting. Rates of daily nest survival did not differ between reforestation strategies. Nest parasitism increased markedly in older cottonwood stands, but was overwhelmed by predation as a cause of nest failure. Based on Partners in Flight prioritization scores and territory densities, the value of cottonwood reforestation for avian conservation was significantly greater than that of oak reforestation during their first 10 years. Because of benefits conferred on breeding birds, we recommend reforestation of bottomland hardwoods include a high proportion of fast-growing, early successional species such as cottonwood.

  7. 90SR uptake by Pinus ponderosa and Pinus radiata seedlings inoculated with ectomycorrhizal fungi

    International Nuclear Information System (INIS)

    Entry, J.A.; Emmingham, W.H.; Rygiewicz, P.T.

    1994-01-01

    Strontium-90 ( 90 Sr) is a radionuclide characteristic of fallout from nuclear reactor accidents and nuclear weapons testing. Prior studies have shown that Pinus ponderosa and P. radiata seedlings can remove appreciable quantities of 90 Sr from soil and store it in plant tissue. In this study, we inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi. Inoculated and noninoculated (control) seedlings were compared for their ability to remove 90 Sr from an organic growth medium. Ectomycorrhizal P. ponderosa and P. radiata seedlings are able to remove 3-5 times more 90 Sr from contaminated soil than seedlings without ectomycorrhizae. (Author)

  8. Métodos de produção de mudas, distribuição de matéria seca e produtividade de plantas beterraba Seedlings production and yield of beet plants

    Directory of Open Access Journals (Sweden)

    Vandeir Francisco Guimarães

    2002-09-01

    Full Text Available Comparou-se desenvolvimento de mudas de beterraba (cv. Tall Top Early Wonder, produzidas por diferentes métodos, através da distribuição de matéria seca na planta. Comparou-se os tratamentos T1 - mudas produzidas em bandejas de 288 células (1,2 x 10-5 m³; T2 - 200 células (1,6 x 10-5 m³ ; T3 - 128 células (3,2 x 10-5 m³; T4 - 128 células (7,2 x 10-5 m³; T5 - semeadura direta e T6 - mudas de raiz nua. Aos 28 dias após a semeadura (DAS, as mudas produzidas em bandejas foram transplantadas para campo, juntamente com mudas de raiz nua (T6. O delineamento experimental foi de blocos ao acaso com quatro repetições. Foram coletadas plantas semanalmente dos 28 aos 98 DAS. Determinou-se a matéria seca das folhas, pecíolos, raízes e da parte aérea e a matéria fresca das raízes. Aos 98 DAS, realizou-se a colheita das raízes comerciais, expressando-se a produtividade em kg ha-1. Para o tratamento T5, o espessamento da raiz tuberosa começou 42 DAS. Por sua vez, as plantas provenientes dos tratamentos T1, T2, T3, T4 e T6 iniciaram o acúmulo de matéria seca nas raízes a partir dos 56 DAS. Os métodos de produção de mudas não influenciaram significativamente na produtividade da cultura, porém aumentaram o ciclo, quando comparado à semeadura direta. Caso a disponibilidade de área seja fator limitante, a produção de mudas em bandejas é recomendável, sendo indicadas bandejas de 288 células.Different methods of beet seedling production were evaluated by distributing dry matter on the plants. The experimental design was of randomized blocks with four replications and six treatments: T1 - seedlings produced in trays of 288 cells (1.2 x 10-5 m³; T2 - 200 cells (1.6 x 10-5 m³; T3 - 128 cells (3.2 x 10-5 m³; T4 - 128 cells (7.2 x 10-5 m³; T5 - direct sowing and T6 - bare-root seedlings. The seedlings produced in trays and the bare-root seedlings were transplanted to the field on the 28th day after the sowing (DAS, with spacing of

  9. Rice seedling and plant development as affected by increasing rates of penoxsulam under controlled environments Desenvolvimento de plântulas e plantas adultas de arroz em função de doses crescentes de penoxsulam em ambiente controlado

    Directory of Open Access Journals (Sweden)

    G. Concenço

    2006-01-01

    Full Text Available Rice is a major staple in many countries. Weed control is one of the factors limiting higher rice yield. ALS (acetolactate synthase-inhibiting herbicides are desirable weed control herbicides because of their high efficacy, low toxicity to mammalians, and low rates used. An important herbicide characteristic is high selectivity to the crop, since it facilitates fast crop establishment and greater crop advantage over the weeds. The objectives of this work were to study the effects of increasing rates of the ALS-inhibiting herbicide penoxsulam on seed integrity and germination, and seedling and plant development of rice cv. BRS Pelota under controlled laboratory and greenhouse conditions. The results showed that penoxsulam affected rice germination and seedling and plant growth at rates above 54 g a.i. ha-1, and that penoxsulam is safe for rice seedling development at the currently recommended rates.O arroz é componente importante da dieta humana em vários países. Entre os fatores que limitam o aumento na sua produtividade está o controle de plantas daninhas. Os herbicidas inibidores da ALS (acetolactato sintase são preferidos em razão da alta eficiência no controle de plantas daninhas, da baixa toxicidade aos mamíferos e das baixas doses utilizadas. Uma característica importante que um herbicida deve possuir é a alta seletividade à cultura, pois ela implica estabelecimento mais rápido, com vantagem competitiva sobre as plantas daninhas. O objetivo deste trabalho foi estudar os efeitos do herbicida inibidor da ALS penoxsulam em doses crescentes sobre a integridade e germinação das sementes, bem como sobre o desenvolvimento inicial das plântulas e da planta adulta do cultivar BRS Pelota, sob condições de ambiente controlado (laboratório e casa de vegetação. Os resultados mostraram que o penoxsulam afetou a germinação e o crescimento de plântulas e plantas adultas nas doses acima de 54 g i.a. ha-1 e que ele é seguro para o

  10. Computer Simulation of a Hardwood Processing Plant

    Science.gov (United States)

    D. Earl Kline; Philip A. Araman

    1990-01-01

    The overall purpose of this paper is to introduce computer simulation as a decision support tool that can be used to provide managers with timely information. A simulation/animation modeling procedure is demonstrated for wood products manufacuring systems. Simulation modeling techniques are used to assist in identifying and solving problems. Animation is used for...

  11. Effects of rhododendron removal on the water use of hardwood species following eastern hemlock mortality

    Science.gov (United States)

    Hawthorne, S. N.; Miniat, C.; Elliott, K.

    2017-12-01

    Forest disturbance that alters vegetation species composition can affect ecosystem productivity and function. The loss of eastern hemlock (Tsuga canadensis) to hemlock woolly adelgid infestations in southern Appalachian Mountains has resulted in more than a two-fold increase in growth of co-occurring rhododendron (Rhododendron maximum) understory, evergreen shrubs. In contrast, the growth of hardwood species increased by 1.2 fold during the same 5 year period following infestation. This study examines the effects of mechanically removing the rhododendron shrub layer on water use and growth of hardwood species. The treatment—hypothesized to speed ecosystem recovery of structure and function—involved cutting, spreading and burning rhododendron stems to remove both rhododendron and soil O-horizon. Sap flow, soil moisture and micro-climate (humidity, temperature) were measured in a pair of reference and treated plots. Preliminary results from the relatively dry summer/fall 2016 have shown that the mean daily transpiration (Et) of the treated plot was 24% greater than the mean daily Et of hardwood trees in the reference plot (t-test, p treatment plots compared to the reference plots. This suggests that the removal of the shrub layer reduced competition for resources for the canopy and seedling trees, which may increase tree growth and recruitment. Thus, in the wake of hemlock loss, recovery of riparian forest structure and function may be aided with shrub layer removal.

  12. Effect of phosphate-solubilizing bacteria isolated from semiarid soils on pitahaya seedlings (Hylocereus undatus)

    OpenAIRE

    Bautista-Cruz, Angélica; Ortiz-Hernández, Yolanda Donají; Martínez-Gallegos, Verónica; Martínez Gutiérrez, Gabino

    2015-01-01

    Phosphate-solubilizing bacteria (PSB) are a group of organisms that solubilize fixed forms of phosphorus, making it available for the plant growth. The effect of three PSB strains, called PSBMi, PSBHc and PSBVa, on growth of pitahaya seedlings (Hylocereus undatus) was studied in a growth chamber. The results indicated that plant stem diameter, plant height, plant total dry weight and root length were greatest in pitahaya seedlings inoculated with PSBMi. The increase in these plant growth vari...

  13. Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

    Science.gov (United States)

    Mary Anne Sword Sayer; Shi-Jean Susana Sung; James D. Haywood

    2011-01-01

    Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling...

  14. Natural products use for protection of seedling in planting trees Uso de produtos naturais para proteção de mudas na arborização de pastagens

    Directory of Open Access Journals (Sweden)

    Valéria Cristina Zago

    2008-04-01

    Full Text Available Conventional productive systems have depleted environmental resources and weakened unsustainable agroecosystems. Silvopastoral systems can be a viable alternative for the recovery of degraded areas. The objective of this experiment was to evaluate natural products used to protect seedlings in planting trees in pastures which the cattle is permanently grazing and the seedlings have no mechanical restraint to keep the cattle away. The experiment was conducted at “Embrapa Gado de Corte”, Mato Grosso do Sul State, Brazil, from February 2nd 2005 to March 28th 2005. The statistical design employed was the split-plot random design, with ten replications. The following treatments were given to the plots: 1 cattle manure around the tree seedlings; 2 dried bovine blood; 3 crushed egg shells; and 4 no protection (control. The subplots contained five tree species: Myroxylon peruiferum (Bálsamo, Dipteryx alata (Cumbaru, Schizolobium parahyba (Guapuruvu, Genipa americana (Jenipapo and Mimosa caesalpineaefolia (Sansão do campo. Herbivory was intense for all treatments. The survival rate of S. parahyba was 72.5%, and 100% of M. caesalpineafolia died. Cattle manure produced the best results, with partial protection of tree seedlings. Application of egg or blood did not offer any protection to the young trees. The concentration and frequency of application of manure for seedling protection deserves further attention.Os sistemas de produção convencional têm esgotado os recursos ambientais, o que torna o agroecossistema frágil e insustentável. Sistemas silvipastoris podem ser alternativas viáveis na recuperação de pastagens degradadas. Este estudo foi desenvolvido com o objetivo de avaliar produtos naturais na implantação de espécies arbóreas em pastagens com presença constante de bovinos, sem proteção das mudas. O experimento foi conduzido na Embrapa Gado de Corte, Campo Grande, MS, no período de 02/02/2005 a 28/03/2005. O delineamento

  15. Management and inventory of southern hardwoods

    Science.gov (United States)

    John A. Putnam; George M. Furnival; J.S. McKnight

    1960-01-01

    The valleys and uplands of the South outside the mountains and upper Piedmont have, since 1915, been responsible for about 45 percent of the national production of hardwood sawtimber. They are strong indications that this situation may continue indefinitely.

  16. Diversity for seedling vigor in wild barley (hordeum vulgare L. subs. simpatina) germplasm

    International Nuclear Information System (INIS)

    Tyagi, K.; Park, M.R.; Lee, H.J.; Lee, C.A.; Rehman, S.; Steffenson, B.; Lee, K.J.; Yun, S.J.

    2011-01-01

    Seedling vigor is important for improving stand establishment of barley crops, particularly in arid regions and areas where the soil temperature is low at sowing time. Three hundred and fifteen wild barley accessions from the Wild Barley Diversity Collection (WBDC) were evaluated for nine seedling vigor traits in a poly house and growth chamber under hydroponic conditions. The accessions exhibited significant differences for all traits investigated. Traits showing greatest phenotypic variation were seedling visual score, plant height, shoot fresh weight, shoot dry weight and shoot length. Seed weight exhibited the least variation. Seed weight was significantly correlated with visual seedling score and shoot and seedling fresh and dry weight. Correlation analysis showed that the visual seedling score was a reliable method for estimating seedling vigor in wild barley. The first three principal components (PC) explained 82.3% of the variation present in the WBDC with PC1(54.0%) associated with shoot fresh weight, shoot dry weight, seedling dry weight, seedling fresh weight, shoot length and seedling length. Accessions from the southwest portion of the Fertile Crescent, like WBDC020 (Turkey), WBDC238 (Jordan) and WBDC244 (Jordan) exhibited the highest positive values for most of the plant vigor traits investigated. These wild barley accessions likely carry alleles that will be useful for the improvement of plant vigor traits in cultivated barley. (author)

  17. RESULTS ON THE EFFECT OF DIFFERENT TYPES OF ROMANIAN NATIVE PEAT BIO COMPOSITES POTS ON SEEDLING GROWTH

    Directory of Open Access Journals (Sweden)

    Florina Uleanu

    2013-07-01

    Full Text Available Seedlings production is an important link in vegetable culture because many vegetables species are grown by producing prior of seedlings. The theme work is in line with Western trends to produce seedlings by integrating new vegetables technologies, profitable, with positive effect on limiting pathogens to obtain seedlings, using biodegradable pots. Were conducted various observations and measurements on plants when they have reached the optimum phase for planting. We have determined: height of seedlings, root length, leaf number, root volume total weight, weight of the aerial and weight of roots. The obtained data was calculated and considered as average / variant.

  18. Long branch-chains of amylopectin with B-type crystallinity in rice seed with inhibition of starch branching enzyme I and IIb resist in situ degradation and inhibit plant growth during seedling development : Degradation of rice starch with inhibition of SBEI/IIb during seedling development.

    Science.gov (United States)

    Pan, Ting; Lin, Lingshang; Wang, Juan; Liu, Qiaoquan; Wei, Cunxu

    2018-01-08

    Endosperm starch provides prime energy for cereal seedling growth. Cereal endosperm with repression of starch branching enzyme (SBE) has been widely studied for its high resistant starch content and health benefit. However, in barley and maize, the repression of SBE changes starch component and amylopectin structure which affects grain germination and seedling establishment. A high resistant starch rice line (TRS) has been developed through inhibiting SBEI/IIb, and its starch has very high resistance to in vitro hydrolysis and digestion. However, it is unclear whether the starch resists in situ degradation in seed and influences seedling growth after grain germination. In this study, TRS and its wild-type rice cultivar Te-qing (TQ) were used to investigate the seedling growth, starch property changes, and in situ starch degradation during seedling growth. The slow degradation of starch in TRS seed restrained the seedling growth. The starch components including amylose and amylopectin were simultaneously degraded in TQ seeds during seedling growth, but in TRS seeds, the amylose was degraded faster than amylopectin and the amylopectin long branch-chains with B-type crystallinity had high resistance to in situ degradation. TQ starch was gradually degraded from the proximal to distal region of embryo and from the outer to inner in endosperm. However, TRS endosperm contained polygonal, aggregate, elongated and hollow starch from inner to outer. The polygonal starch similar to TQ starch was completely degraded, and the other starches with long branch-chains of amylopectin and B-type crystallinity were degraded faster at the early stage of seedling growth but had high resistance to in situ degradation during TRS seedling growth. The B-type crystallinity and long branch-chains of amylopectin in TRS seed had high resistance to in situ degradation, which inhibited TRS seedling growth.

  19. California's hardwood resource: history and reasons for lack of a sustained hardwood industry

    Science.gov (United States)

    Dean W. Huber; Philip M. McDonald

    1992-01-01

    Interest in utilizing California's forest-zone hardwoods for lumber and wood products has waxed and waned for more than 140 years. In spite of many unsuccessful ventures, strong interest is once again evident from landowners, processors, consumers, and policy makers. Their interest suggests a need to know past pitfalls, to recognize some realities of hardwood...

  20. Urban solid waste in the production of Lafoensia pacari seedlings

    Directory of Open Access Journals (Sweden)

    Alan H. M. de Abreu

    Full Text Available ABSTRACT This study aimed to verify the potential of urban solid wastes as substrate for production of seedlings of Lafoensia pacari. Five treatments were tested, four with solid wastes and one standard substrate, namely: sewage sludge from Alegria Wastewater Treatment Plant (WTP; sewage sludge from Ilha do Governador WTP; sewage sludge from Sarapuí WTP; domestic garbage compost (Fertlurb; and a commercial substrate made of biostabilized pine bark (standard substrate. The wastes received 20% (in volume of shredded coconut fiber. At 105 days after sowing, the seedlings were evaluated for different quality parameters. Seedlings produced with Sarapuí WTP sewage sludge showed the best results in all the parameters, followed by seedlings produced with sewage sludge from Alegria and Ilha do Governador WTPs, which did not differ. Seedlings produced with domestic garbage compost showed satisfactory results, higher than the ones observed for seedlings produced with commercial substrate. The urban solid wastes with 20% of coconut fiber showed high potential and can be recommended for the composition of substrate in the production of Lafoensia pacari seedlings.

  1. Effects of benzoic acid and cadmium toxicity on wheat seedlings

    Directory of Open Access Journals (Sweden)

    Kavita Yadav

    2013-06-01

    Full Text Available Benzoic acid (BA and Cd exhibit cumulative effects on plants due to their accumulation in the soil. The present study reports the effects of BA an allelochemical, Cd and their combinations on seed germination, seedling growth, biochemical parameters, and response of antioxidant enzymes in Triticum aestivum L. The experiment was conducted in sand supplemented with Hoagland nutrient solution. Benzoic acid was applied at concentrations of 0.5, 1.0, and 1.5 mM with or without Cd (7 mg L-1 to observe effects of allelochemical and Cd alone and in combination on wheat. Both stresses exhibited inhibitory effect on growth and metabolism of wheat seedlings. The allelochemical in single and combined treatments with Cd decreased seedling growth as compared to Cd stress. The two stresses significantly enhanced malondialdehyde content of wheat seedlings. The activity of other antioxidant enzymes, viz. superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase (APX, and guaiacol peroxidase (POX were also recorded. SOD increased in seedlings under the two stresses. CAT more prominently ameliorates the toxic effects of H2O2 as compared with APX and POX and protected wheat seedlings from oxidative stress. Allelochemical buttressed the toxic effect of Cd on wheat seedlings.

  2. A management guide for northern hardwoods in New England

    Science.gov (United States)

    Adrian M. Gilbert; Victor S. Jensen

    1958-01-01

    Northern hardwood forests occupy about 9 million acres of land in New England. In recent years, these hardwood forests have made increasing contributions to the economy of this region. Their future management should be even more rewarding.

  3. Impact of climate change, seedling type and provenance on the risk of damage to Norway spruce (Picea abies (L.) Karst.) seedlings in Sweden due to early summer frosts

    Energy Technology Data Exchange (ETDEWEB)

    Langvall, Ola (Swedish Univ. of Agricultural Sciences, Unit for Field-based Forest Research, Asa Forest Research Station, Lammhult (Sweden))

    2011-04-15

    A model including site-specific microclimate-affecting properties of a forest regeneration area together with seedling characteristics was used to evaluate the accumulated risk of frost damage to Norway spruce (Picea abies (L.) Karst.) seedlings. Climate change in Sweden was simulated on the basis of the regional climate model RCA3. The daily average temperature, the driving factor for bud burst in the model, was adjusted using the difference between the mean of the climate model data for the years 1961-1990 and 2036-2065. The model was run for a highly frost prone, clear-cut site in which bare-rooted Norway spruce seedlings of mid-Swedish provenance were planted. Alternate runs were conducted with data for containerized seedlings and seedlings of Belarusian origin. The study showed that bud burst will occur at earlier dates throughout Sweden in the period 2036-2065 if the climate changes according to either of the climate scenarios examined, compared to the reference period 1961-1990. Furthermore, the risk of damage to Norway spruce seedlings as a result of frost events during summer will increase in southern Sweden and be unaffected or decrease in northern Sweden. The risk of frost damage was exacerbated in containerized seedlings, while the risk was lower for the seedlings of Belarusian provenance when compared with bare-rooted seedlings or seedlings of mid-Swedish origin

  4. Seedling Composition and Facilitative Effects of the Herbaceous Layer in a Monsoon-Affected Forest in Nanjenshan, Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Su-Wei Fan

    2010-11-01

    Full Text Available Tree seedlings play an important role in forest regeneration. To understand the factors that control seedling establishment, we (1 compared the composition patterns of tree seedlings and their corresponding overstories, (2 examined the relationships between seedling composition and environmental factors and (3 evaluated the interaction (competition or facilitation between seedlings and herbaceous layer in a wind-stressed forest in Nanjenshan, southern Taiwan. In the study plot, seedling abundance of canopy, subcanopy and shrub species (with true leaves and < 1 cm diameter at breast height and coverage of herbaceous species (including herbaceous species, climbers and tree ferns ≤ ca. 1 m in height were investigated on three transects with a total of 180 contiguous 5 × 5 m quadrats. Clustering classification and ordination methods were used to reveal the tree seedling composition patterns and the relationships between seedling composition and environmental factors. Correlation coefficients were computed between herbaceous coverage and seedling abundance among herb-seedling species pairs and between tall (≥ 1 m high/short (< 0.5 m high herbs and seedlings pairs to test the herb-seedling interaction. The spatial distribution of tree seedlings presented a perfect match to the overstory vegetation pattern. There was a strong relationship among seedling composition, herbaceous composition and topographic features, especially exposure to monsoon winds. Because of the absence of strong correlations between herbaceous structure/species and seedling abundances, the strong linkage in spatial patterns between seedling and herbaceous compositions suggests that certain plant species in the study plot have similar responses to the monsoon exposure. Our results also indicated that seedlings < 1 cm in diameter were strongly influenced by wind stress, similar to the response of the overstory composition, and that the facilitative/competitive effects of the

  5. Seedling recruitment of forb species under experimental microhabitats in alpine grassland

    International Nuclear Information System (INIS)

    Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.

    2015-01-01

    Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)

  6. Identification of zygotic and nucellar seedlings in citrus interspecific ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... Department of Plant Breeding and Improvement, Iran Citrus Research Institute, Mottahari Street, Ramsar, .... (C. aurantium) rootstock plants for further agronomic evaluation .... literatures may be attributed to pollination efficiency and ... zygotic seedlings in Swingle citromelo Citrus paradisi × Poncirus tifoliata.

  7. Sugar signalling during germination and early seedling establishment in Arabidopsis

    NARCIS (Netherlands)

    Dekkers, S.J.W.

    2006-01-01

    Sugars have pronounced effects on many plant processes like gene expression, germination and early seedling development. Several screens for sugar insensitive mutants were performed to identify genes involved in sugar response pathways using the model plant Arabidopsis. These include sun, gin and

  8. Protejarea puieţilor de răşinoase împotriva atacului de Hylobius abietis prin îmbăiere în Supersect 10EC şi Nu-Film 17 [Protection of conifer seedlings against pine weevil (Hylobius abietis feeding by dipping into Supersect 10EC and Nu-Film 17 before planting

    Directory of Open Access Journals (Sweden)

    Olenici N

    2002-07-01

    Full Text Available Protection of seedlings afforded by Supersect 10EC alone and Supersect 10EC mixed with NuFilm 17 against pine weevil feeding was evaluated in field experiments in northern part of Romania. The seedlings, mainly of Norway spruce, but also European larch and Black pine, have been treated by dipping into insecticide solution (1 % Supersect or 1 % Supersect plus 1 % Nu-Film just before planting of the seedlings in three new clear-cutting areas. The efficacy of the treatment was evaluated after 3-5 months. The frequency of attack in Norway spruce seedlings was reduced by 21.4-61.1% when Supersect was used together with Nu-Film, but only by 0-35.5 % when it was used alone. For the same species, the intensity of attack was diminished by 62.4-83,2 % when the treatment was done with Supersect and Nu-Film, and by 48.7-63.3 % when it was used only Supersect. For the other two species, the efficacy of treatment was generally lower. The tests showed that in new clear-cuttings, where the weevil population level is very high and the weevils are active for a long time, the treatment could be efficiently enough only during the first 2- 3 months especially during the years with rainy weather. Consequently, additional protective measure should be applied in such situations. In order to achieve a good efficiency, the stems of the seedlings should be clear and dry before the treatment, and after the treatment the seedlings should be protected against the rain until the insecticide dries up on them. Higher concentrations of insecticides could give better results, but this should be proved in other tests.

  9. Are there regional differences in US hardwood product exports?

    Science.gov (United States)

    Matt Bumgardner; Scott Bowe; William Luppold

    2016-01-01

    Exporting is a critical component of the product mix for many domestic hardwood firms. Previous research has identified factors associated with hardwood lumber exporting behavior, but less is known about the advantages and disadvantages to exporting associated with the region within which a firm is located, or about exporting of secondary hardwood products. A procedure...

  10. Growth and shifts in eastern hardwood lumber production

    Science.gov (United States)

    William G. Luppold; Gilbert P. Dempsey

    1993-01-01

    An analysis of recent trends in eastern U.S. hardwood lumber production indicates that total output increased sharply between 1977 and 1991. The increase, however, was much more pronounced in the East's northern tier of states than in the southern. This paper first examines recent hardwood lumber usage trends and historic hardwood lumber production trends. Changes...

  11. 40 years of hardwood lumber comsumption: 1963 to 2002

    Science.gov (United States)

    William Luppold; Matthew Bumgardner

    2008-01-01

    An analysis of hardwood lumber consumption found that demand has changed dramatically over the past four decades as a result of material substitution, changes in construction and remodeling products markets, and globalization. In 1963 furniture producers consumed 36 percent of the hardwood products lumber used by domestic manufacturers. Producers of hardwood...

  12. U.S. Hardwood Imports Grow as World Supplies Expand

    Science.gov (United States)

    William C. Siegel; Clark Row

    1965-01-01

    Rapidly increasing imports have captured a significant share of America's hardwood markets. Total imports of hardwood raw materials and building products are now four times as large as exports. Before World War II the U. S. was a net exporter of hardwoods, and imports were limited to high-quality mahogany and specialty logs and lumber. Availability of large...

  13. Effect of vertical integration on the utilization of hardwood resources

    Science.gov (United States)

    Jan Wiedenbeck

    2002-01-01

    The effectiveness of vertical integration in promoting the efficient utilization of the hardwood resource in the eastern United States was assessed during a series of interviews with vertically integrated hardwood manufacturers in the Appalachian region. Data from 19 companies that responded to the 1996 phone survey indicate that: 1) vertically integrated hardwood...

  14. Acclimatization and growth of ornamental pineapple seedlings under organic substrates

    Directory of Open Access Journals (Sweden)

    Ronan Carlos Colombo

    2017-09-01

    Full Text Available The in vitro propagation techniques are commonly used to produce ornamental pineapple seedlings in commercial scale, aiming to attend the growers with genetic and sanitary quality seedlings. However, the choice of the ideal substrate is essential for the acclimatization and growth stage of the seedlings propagated by this technique, since some substrates can increase the seedling mortality and/or limit the seedling growth due to its physical and chemical characteristics. Thus, the aim of this study was to evaluate the acclimatization of ornamental pineapple [Ananas comosus (L. Merr. var. ananassoides (Baker Coppens & Leal] on different substrates. Seedlings with approximately seven centimeters, obtained from in vitro culture, were transplanted into styrofoam trays filled with the following substrates: sphagnum; semi-composed pine bark; carbonized rice husk; sphagnum + semicomposed pine bark; sphagnum + carbonized rice husk; and semi-composed pine bark + carbonized rice husk. Each treatment was replicated five times using 10 plants. At 180 days, there were evaluated the following variables: survival percentage, plant height, number of leaves, leaf area, largest root length, and shoot and root dry matter. The substrate semi-composed pine bark + carbonized rice husk presented the lowest mean (62% for survival percentage. The semi-composed pine bark and semi-composed pine bark + carbonized rice husk treatments presented significant increments in some evaluated biometric characteristics. The semi-composed pine bark is the most favorable substrate for the A. comosus var. ananassoids acclimatization.

  15. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  16. Seedlings Of Ocotea puberula (Lauraceae): identification and monitoring of aporphinoid alkaloids; Mudas de Ocotea puberula (Lauraceae): identificacao e monitoramento de alcaloides aporfinoides

    Energy Technology Data Exchange (ETDEWEB)

    Zanin, Sandra Maria Warumby; Miguel, Obdulio Gomes; Montrucchio, Deise Prehs; Costa, Camila Klocker; Lagos, Jesse Boquett [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Farmacia; Lordello, Ana Luisa Lacava, E-mail: lordello@ufpr.b [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica

    2011-10-26

    This work describes the occurrence and contents of aporphinoids alkaloids in seedlings of Ocotea puberula from germination until 12 months old and in leaves from adult plants. Seedling leaves showed an alkaloids profile similar to leaves of adult plant. However, leaves in seedlings showed higher contents of the alkaloids boldine, dicentrine, leucoxine and isodomesticine when compared to adult plants. The alkaloids concentration in stems and leaves increased during the development of the seedlings, followed by a remarkable decrease of these compounds in roots. Cultivation in a seedling-nursery method is also described. (author)

  17. Effects of photoperiod, plant growth regulators and culture media on in vitro growth of seedlings of Cyrtochilum loxense (Lindl. Kraenzl. an endemic and endangered orchid from Ecuador

    Directory of Open Access Journals (Sweden)

    Yadira González

    2014-10-01

    Full Text Available Cyrtochilum loxense (Lindl. Kraenzl. is an endemic and seriously endangered orchid species endemic in the Loja Province (Southern Ecuador. The main goals of this research were to analyze how culture media, plant growth regulators and photoperiod affect the growth of C. loxense. Eight month old plants (approximate 1 – 1.5 cm in height obtained by in vitro germination, were cultivated on MS media or Knudson C; MS with three levels of naphthalene acetic acid (NAA and 6-benzylaminopurine (BAP (2/0.5; 1/0.5 y 0.5/ 0.5 mg-1L; and three photoperiodic regimes (24/0, 16/8, 8/16 h on MS with and without plant growth regulators. No significant differences of shoot induction were observed on media with or without plant growth regulators, and all tested photoperiods. The highest growth (1.2 cm was observed in plantlets cultivated on growth regulator-free media with a 16/8 photoperiod. Also the shoot and root formation was better in this species in absence of plant growth regulators. Probably this response is due to the endogenous hormone levels in the tissues or due to the kind and concentrations of PGRs used were too low to induce positive morphogenetic responses.

  18. Synthesis of ectomycorrhizae on northern red oak seedlings in a Michigan nursery

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, R.K.; Johnson, P.S.

    1993-01-01

    Vegetative inoculum of the ectomycorrhizal fungus Suillus luteus was thoroughly mixed into fumigated nursery soil, and northern red oak seedlings of four families were evaluated one and two years after sowing for ectomycorrhizal development, growth, and nutrition. At the end of year one, treated seedlings were successfully inoculated with S. luteus, but the percentage varied significantly with family. Suillus luteus persisted on lateral roots two years following sowing. Two of four seedling families inoculated with S. luteus were significantly larger in size than control plants. These results suggest that the fungal symbiont S. luteus can be successfully introduced into nurseries and that early ectomycorrhizal development improves the growth of northern red oak seedlings.

  19. AMMONIUM TOXICITY AND NITRATE RESPONSE OF AXENICALLY GROWN DACTYLORHIZA-INCARNATA SEEDLINGS

    NARCIS (Netherlands)

    DIJK, E; ECK, N

    1995-01-01

    The response to ammonium- and nitrate-nitrogen of seedlings of the calcicole orchid species Dactylorhiza incarnata (L.) Soo was tested in axenic in vitro culture of c. 3-month-old protocorms. A pronounced toxicity of ammonium ions was observed. Seedlings raised from plants of a coastal population

  20. Innovating a system for producing and distributing hybrid oil palm seedlings to smallholder farmers in Benin

    NARCIS (Netherlands)

    Vissoh, Pierre V.; Tossou, Rigobert C.; Akpo, Essegbemon; Kossou, Dansou; Jiggins, Janice

    2017-01-01

    This article analyses the development of a system for producing and distributing hybrid oil palm seedlings to small-scale famers. The existing seed system had become so corrupted that the seedlings actually planted were largely of unimproved kinds. The article describes institutional experiments

  1. Root morphology and growth of bare-root seedlings of Oregon white oak

    Science.gov (United States)

    Peter J. Gould; Constance A. Harrington

    2009-01-01

    Root morphology and stem size were evaluated as predictors of height and basal-area growth (measured at groundline) of 1-1 Oregon white oak (Quercus garryana Dougl. ex Hook.) seedlings planted in raised beds with or without an additional irrigation treatment. Seedlings were classified into three root classes based on a visual assessment of the...

  2. The role of large container seedlings in afforesting oaks in bottomlands

    Science.gov (United States)

    Daniel C. Dey; John M. Kabrick; Michael Gold

    2006-01-01

    We planted large container (RPM®) and 1-0 bareroot seedlings of pin oak (Quercus palustris Muenchh.) and swamp white oak (Q. bicolor Willd.) in crop fields in the Missouri River floodplain. We also evaluated the benefits of soil mounding and a grass (Agrostis gigantea Roth) cover crop. RPM®) oak seedlings had significantly greater...

  3. A systems genetics study of seed quality and seedling vigour in Brassica rapa

    NARCIS (Netherlands)

    Basnet, R.K.

    2015-01-01

    Summary

    Seed is the basic and most critical input for seed propagated agricultural crops: seed quality and seedling vigour determine plant establishment, growth and development in both natural and agricultural ecosystems. Seed quality and seedling vigour are mainly

  4. The impact of the herbicide atrazine on growth and photosynthesis of seagrass, Zostera marina (L.), seedlings

    International Nuclear Information System (INIS)

    Gao Yaping; Fang Jianguang; Zhang Jihong; Ren Lihua; Mao Yuze; Li Bin; Zhang Mingliang; Liu Dinghai; Du Meirong

    2011-01-01

    Highlights: → Impact of the widely used herbicide atrazine on eelgrass seedlings was studied. → Atrazine presents a threat to eelgrass seedlings growth and photosynthesis. → The impact of atrazine on eelgrass seedlings is much higher than for adult plants. - Abstract: The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants.

  5. Colonization with Arbuscular Mycorrhizal Fungi Promotes the Growth of Morus alba L. Seedlings under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2015-03-01

    Full Text Available Morus alba L. is an important tree species planted widely in China because of its economic value. In this report, we investigated the influence of two arbuscular mycorrhizal fungal (AMF species, Glomus mosseae and Glomus intraradices, alone and together, on the growth of M. alba L. seedlings under greenhouse conditions. The growth parameters and physiological performance of M. alba L. seedlings were evaluated 90 days after colonization with the fungi. The growth and physiological performance of M. alba L. seedlings were significantly affected by the AMF species. The mycorrhizal seedlings were taller, had longer roots, more leaves and a greater biomass than the non-mycorrhizae-treated seedlings. In addition, the AMF species-inoculated seedlings had increased root activity and a higher chlorophyll content compared to non-inoculated seedlings. Furthermore, AMF species colonization increased the phosphorus and nitrogen contents of the seedlings. In addition, simultaneous root colonization by the two AMF species did not improve the growth of M. alba L. seedlings compared with inoculation with either species alone. Based on these results, these AMF species may be applicable to mulberry seedling cultivation.

  6. Implications of seed size for seedling survival in Carnegiea gigantea and Ferocactus wislizeni (Cactaceae)

    Science.gov (United States)

    Bowers, Janice E.; Pierson, E.A.

    2001-01-01

    Larger seeds have been shown to convey benefits for seedling survival but the mechanisms of this process are not well understood. In this study, seed size and seedling survival were compared for 2 sympatric cactus species, Carnegiea gigantea (Engelm.) Britt. & Rose and Ferocactus wislizeni (Engelm.) Britt. & Rose, in laboratory and field experiments in the northern Sonoran Desert. Both species have small seeds, but Ferocactus seeds are nearly twice as long and 3 times as heavy as those of Carnegiea. The difference in size is perpetuated after germination: new Ferocactus seedlings have 4 times the estimated volume of new Carnegiea seedlings. In an outdoor experiment, annual survivorship of both species was low but was 6 times higher for Ferocactus (6 seedlings, 8.1%) than Carnegiea (1 seedling, 1.4%). The pattern of seedling mortality in relation to temperature and rain suggests that, after the initial flush of seed and seedling predation, drought and heat took a greater toll on Carnegiea than Ferocactus seedlings, probably because the larger seedling volume of Ferocactus conferred greater drought tolerance. In addition, F. wislizeni could become established without benefit of nurse plants whereas C. gigantea could not; this might reflect differential tolerance to high soil temperatures.

  7. Accumulation of Monoterpenoid Indole Alkaloids in Periwinkle Seedlings ("Catharanthus roseus") as a Model for the Study of Plant-Environment Interactions

    Science.gov (United States)

    Miranda-Ham, Maria de Lourdes; Islas-Flores, Ignacio; Vazquez-Flota, Felipe

    2007-01-01

    Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using…

  8. Molecular biology of Ganoderma pathogenicity and diagnosis in coconut seedlings.

    Science.gov (United States)

    Kandan, A; Radjacommare, R; Ramanathan, A; Raguchander, T; Balasubramanian, P; Samiyappan, R

    2009-01-01

    The pathogenicity of Ganoderma boninense was tested on coconut seedlings under greenhouse conditions and infection confirmed by using immunological and molecular diagnostic tools. Desiccation of older leaves and the emergence of sporophores were observed from pathogen-inoculated seedlings, whereas a control seedling does not show any pathogenic symptoms. Mature sporophores were formed within 10-13 weeks after inoculation. Polyclonal antibodies raised against mycelial proteins of Ganoderma were used for detection of Ganoderma in infected field palm and seedlings through indirect enzyme-linked immunosorbent assay technique. We adopted dot-immunobinding assay for the detection of Ganoderma from greenhouse and field samples. Under nucleic-acid-based diagnosis, G. boninense (167 bp) was detected from artificially inoculated seedlings and infected field palms by polymerase chain reaction. Apart from these, histopathological studies also support the Ganoderma pathogenicity in coconut seedlings. The pathogenicity test and combination of all the three diagnostic methods for Ganoderma could be highly reliable, rapid, sensitive and effective screening of resistance in planting material in the future.

  9. Promoting and maintaining diversity in contemporary hardwood forests: Confronting contemporary drivers of change and the loss of ecological memory

    Science.gov (United States)

    Christopher R. Webster; Yvette L. Dickinson; Julia I. Burton; Lee E. Frelich; Michael A. Jenkins; Christel C. Kern; Patricia Raymond; Michael R. Saunders; Michael B. Walters; John L. Willis

    2018-01-01

    Declines in the diversity of herbaceous and woody plant species in the understory of eastern North American hardwood forests are increasingly common. Forest managers are tasked with maintaining and/or promoting species diversity and resilience; however, the success of these efforts depends on a robust understanding of past and future system dynamics and identification...

  10. The wheat WRKY transcription factors TaWRKY49 and TaWRKY62 confer differential high-temperature seedling-plant resistance to Puccinia striiformis f. sp. tritici.

    Directory of Open Access Journals (Sweden)

    Junjuan Wang

    Full Text Available WRKY transcription factors (TFs play crucial roles in plant resistance responses to pathogens. Wheat stripe rust, caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst, is a destructive disease of wheat (Triticum aestivum worldwide. In this study, the two WRKY genes TaWRKY49 and TaWRKY62 were originally identified in association with high-temperature seedling-plant resistance to Pst (HTSP resistance in wheat cultivar Xiaoyan 6 by RNA-seq. Interestingly, the expression levels of TaWRKY49 and TaWRKY62 were down- and up-regulated, respectively, during HTSP resistance in response to Pst. Silencing of TaWRKY49 enhanced whereas silencing TaWRKY62 reduced HTSP resistance. The enhanced resistance observed on leaves following the silencing of TaWRKY49 was coupled with increased expression of salicylic acid (SA- and jasmonic acid (JA-responsive genes TaPR1.1 and TaAOS, as well as reactive oxygen species (ROS-associated genes TaCAT and TaPOD; whereas the ethylene (ET-responsive gene TaPIE1 was suppressed. The decreased resistance observed on leaves following TaWRKY62 silencing was associated with increased expression of TaPR1.1 and TaPOD, and suppression of TaAOS and TaPIE1. Furthermore, SA, ET, MeJA (methyl jasmonate, hydrogen peroxide (H2O2 and abscisic acid (ABA treatments increased TaWRKY62 expression. On the other hand, MeJA did not affect the expression of TaWRKY49, and H2O2 reduced TaWRKY49 expression. In conclusion, TaWRKY49 negatively regulates while TaWRKY62 positively regulates wheat HTSP resistance to Pst by differential regulation of SA-, JA-, ET and ROS-mediated signaling.

  11. Studies on the seedling growth of Adansonia digitata AL. | Chia ...

    African Journals Online (AJOL)

    The germination and growth of seedlings of Adansonia digitata were investigated at the Biological garden of ABU Zaria, Nigeria (07o38′ and 11o11′N) at different planting depths and soil types. The seeds were planted at different planting depths of 1.0 cm, 2.0 cm, 4.0 cm and 6.0 cm in nursery bags and kept in a screen ...

  12. Manganese (Mn) stress toward hyperaccumulators plants combination (HPC) using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition on soybean (Glycine max) seedling stage

    Science.gov (United States)

    Darmawan, Tania Sylviana; Zahroh, Tata Taqiyyatuz; Merindasya, Mirza; Masfaridah, Ririn; Hartanti, Dyah Ayu Sri; Arum, Sekar; Nurhatika, Sri; Muhibuddin, Anton; Surtiningsih, Tini; Arifiyanto, Achmad

    2017-06-01

    Heavy metals were a metal bracket which had a specific gravity greater than 5 g / cm3. Manganese was one of them because it has a specific gravity of 7.4 g / cm3. Together with widespread cases of soil contamination caused by heavy metals as well as increased development of the science of breeding ground rapidly, then the alternative rehabilitation techniques were relatively cheap and effective it needs to be developed and even some cases of contaminated management soil using a combination of plants with microorganisms to be more effective. Thus it was necessary to develop research on plants that were able to accumulate heavy metals and other toxic materials, such as Mn so that the land becomes safe for health and the environment. Based on above reason this research aimed to see the influence of hyperaccumulators combination of plants using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition to stressed by manganese (Mn) on soybean (Glycine max). Observations of growth, chlorophyll content and heavy metals analysis performed on nine treatments (P1-P9) and one control (P0). The results showed a combination of hyperaccumulators under mychorrizal helped overcome the stress of manganese (Mn) in the leaves of soybean (G. max). It gave an influence on the number of leaves and chlorophyll content of soybean (G. max), but no effect performed on the height and the roots of soybean (G. max). The use of plants in small amounts hyperaccumulators (P1;1 jatropha and 1 lamtoro) was sufficient to cope with stress of Mn in the leaves of soybean (G. max).

  13. Salinity tolerance of Dodonaea viscosa L. inoculated with plant growth-promoting rhizobacteria: assessed based on seed germination and seedling growth characteristics

    Directory of Open Access Journals (Sweden)

    Yousefi Sonia

    2017-06-01

    Full Text Available The study was conducted to evaluate the potential of different strains of plant growth-promoting rhizobacteria (PGPR to reduce the effects of salinity stress on the medicinal hopbush plant. The bacterium factor was applied at five levels (non-inoculated, inoculated by Pseudomonas putida, Azospirillum lipoferum + Pseudomonas putida, Azotobacter chroococcum + Pseudomonas putida, and Azospirillum lipoferum + Azotobacter chroococcum + Pseudomonas putida, and the salinity stress at six levels: 0, 5, 10, 15, 20, and 50 dS m-1. The results revealed that Pseudomonas putida showed maximal germination percentage and rate at 20 dS m-1 (18.33% and 0.35 seed per day, respectively. The strongest effect among the treatments was obtained with the treatment combining the given 3 bacteria at 15 dS m-1 salinity stress. This treatment increased the root fresh and dry weights by 31% and 87.5%, respectively (compared to the control. Our results indicate that these bacteria applied on hopbush affected positively both its germination and root growth. The plant compatibility with the three bacteria was found good, and the treatments combining Pseudomonas putida with the other one or two bacteria discussed in this study can be applied in nurseries in order to restore and extend the area of hopbush forests and akin dry stands.

  14. Endophytic fungi reduce leaf-cutting ant damage to seedlings

    Science.gov (United States)

    Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

    2011-01-01

    Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

  15. Sobrevivência de espécies arbóreas plantadas em clareiras causadas pela colheita de madeira em uma floresta de terra firme no município de Paragominas na Amazônia brasileira Survival of seedlings planted in gaps after harvesting in a terra firme rain forest in Paragominas region in the Brazilian Amazonia

    Directory of Open Access Journals (Sweden)

    Jaqueline Macêdo Gomes

    2010-03-01

    Full Text Available Analisou-se a sobrevivência de mudas plantadas em 400 clareiras causadas por exploração florestal de impacto reduzido, em floresta de terra firme na Amazônia Oriental. Foram plantadas 3.818 mudas de 17 espécies, das quais apenas Schizolobium amazonicum não ocorre na área de estudo. A distância entre as mudas plantadas foi de aproximadamente 5m. As avaliações ocorreram em 2005 e 2006. Com base na sobrevivência das mudas aos 11 meses após o plantio, as espécies indicadas para o enriquecimento de clareiras são: Schizolobium amazonicum, Cedrela odorata, Jacaranda copaia, Manilkara huberi, Astronium gracile, Pouteria bilocularis, Tabebuia impetiginosa,Pseudopiptadenia suaveolens, Cordia goeldiana, Parkia gigantocarpa, Simarouba amara, Sterculia pilosa, Laetia procera, Dinizia excelsa e Schefflera morototoni. Estudos sobre a taxa de crescimento, em períodos mais longos, são necessários para confirmar a utilização dessas espécies em plantios de enriquecimento de clareiras oriundas de exploração florestal, como alternativa para aumentar a produtividade e o valor econômico das florestas naturais manejadas na Amazônia brasileira.Survival of seedlings planted in 400 gaps created by reduced impact logging in a terra firme forest in the Eastern Amazonia was evaluated. 3,818 seedlings from 17 species occurring in the study area, except for Schizolobium amazonicum (paricá, which is rare in natural forests of Paragominas region, were planted in the gaps. Spacing of planted seedlings was 5m. According to survival of seedlings during 11 months after planting, the species Schizolobium amazonicum, Cedrela odorata, Jacaranda copaia, Manilkara huberi, Astronium gracile, Pouteria bilocularis, Tabebuia impetiginosa,Pseudopiptadenia suaveolens, Cordia goeldiana, Parkia gigantocarpa, Simarouba amara, Sterculia pilosa, Laetia procera, Dinizia excelsa and Schefflera morototoni can be suggested for enriching in gaps created by reduced impact logging

  16. Controle de plantas daninhas na produção de mudas de plantas ornamentais Weed control in ornamental plant seedling production

    Directory of Open Access Journals (Sweden)

    F.C.L. Freitas

    2007-09-01

    g ha-1 de oxyfluorfen, para plantas de copo-de-leite, estrelítzia e palmeira-australiana, respectivamente, na aplicação em área total, e nas concentrações superiores a 0,0018%, na aplicação dirigida, aos 30 DAA.This study aimed to evaluate efficacy of oxyfluorfen in controlling Pilea microphylla for the production of ornamental plant shoots. Two experiments were carried out in a randomized block design, arranged in a factorial scheme 2 x 7, with three replicates. One trial was composed by three ornamental plant species (Zantedeschia aethiopica, Strelitzia reginae and Archontophoenix cunninghamiana and seven oxyfluorfen rates (0, 24, 72, 144, 216, 288 and 360 g ha-1, sprayed in a total area; the other trial was composed by the same species and seven oxyfluorfen concentrations (0.00000, 0.00036, 0.00072, 0.00144, 0.00288, 0.00576 and 0.01152% of a.i. applied directly as spray, without reaching the ornamental plant leaves. Each experimental unit was represented by a pot with an ornamental plant shoot, infested with Pilea microphylla. At 15, 30 and 60 days after application (DAA visual evaluations of the control on P. microphylla and toxicity on ornamental plants were carried out. For the total area spray, the A. cunninghamiana plant pots demanded high herbicide doses due to this species' larger foliar area, during application, making the herbicide contact with weeds difficult. Still in this application modality,light intoxication symptoms were observed in the ornamental plants, being more evident in the A. cunninghamiana plants. For the direct spray modality, no interaction among the factors, species and herbicide concentration, nor herbicide behavior differences were observed for the characteristics evaluated. Intoxication was not observed in the ornamental plants in none of the treatments evaluated, for the direct spray modality. Efficient P. microphylla control was verified for rates above 90% at 300, 320 and 340 kg ha-1 of oxyfluorfen, plants of Z

  17. Resistance to Phytophthora cinnamomi among seedlings from backcross families of hybrid american chestnut

    Science.gov (United States)

    Steven N. Jeffers; Inga M. Meadows; Joseph B. James; Paul H. Sisco

    2012-01-01

    American chestnut (Castanea dentata (Marsh.) Borkh.) once was a primary hardwood species in forests of the eastern United States. Sometime during the late 18th century, it is speculated that Phytophthora cinnamomi, which causes Phytophthora root rot (PRR) on many woody plant species, was introduced to the southeast region of...

  18. Bioaccumulation of hexachlorobutadiene in pumpkin seedlings after waterborne exposure.

    Science.gov (United States)

    Hou, Xingwang; Zhang, Haiyan; Li, Yanlin; Yu, Miao; Liu, Jiyan; Jiang, Guibin

    2017-10-18

    Hexachlorobutadiene (HCBD) has been listed as a persistent organic pollutant (POP) in the Stockholm Convention, and is now drawing more and more research interest. However, the understanding of its bioaccumulation, especially in plants, is still very limited. In this work, the behavior of HCBD in aqueous solution and pumpkin seedlings was studied through in-lab hydroponic exposure experiments. It was found that 69% of HCBD volatilized from water to the atmosphere after one day of exposure, and only 1% remained in the solution after four days. This high volatility might be the main cause of the low HCBD levels in aqueous environments. Although a great amount of HCBD volatilized into the atmosphere, only a small proportion of airborne HCBD was captured by the leaves and stems of the blank pumpkin seedling controls. The translocation of HCBD from the leaves to the bottom roots, as well as its release from the roots into the water, was detected. For the exposure groups, the pumpkin seedlings absorbed HCBD from both the hydroponic solution and the air via the roots and leaves, respectively. The concentration of HCBD in the exposed pumpkin roots linearly increased with the continuous addition of HCBD into the exposure system. Upward translocation from the roots to the leaves and downward translocation from the leaves to the roots existed simultaneously in the exposed pumpkin seedlings. However, the concentrations of HCBD in the leaves, stems and roots in the exposure group were much higher than those of the blank plant controls, suggesting little contribution from the airborne HCBD in the hydroponically exposed pumpkin seedlings. The lipid content did not show obvious effects on the bioaccumulation and biodistribution of HCBD in the pumpkin seedlings, indicating that the translocation of HCBD within the pumpkin seedlings might be an active process. This study provided new findings on the environmental behavior of HCBD, which will be helpful for understanding the exposure

  19. A Dynamic Model of California's Hardwood Rangelands

    Science.gov (United States)

    Richard B. Standiford; Richard E. Howitt

    1991-01-01

    Low profitability of hardwood rangeland management, and oak tree harvesting for firewood markets and forage enhancement has led to concern about the long-term sustainability of the oak resource on rangelands. New markets for recreational hunting may give value to oaks for the habitat they provide for game species, and broaden the economic base for managers. A ranch...

  20. Guide to Regeneration of Bottomland Hardwoods

    Science.gov (United States)

    Martha R. McKevlin

    1992-01-01

    This guide will help landowners, consulting foresters, and public service foresters regenerate bottomland hardwoods. It discusses (1) interpretation of site characteristics, (2) selection of species, and (3) selection of regeneration methods. A dichotomous key for selection of appropriate regeneration methods under various conditions is presented.

  1. Placing our northern hardwood woodlots under management

    Science.gov (United States)

    Russell J. Hutnik

    1956-01-01

    Do you own a woodlot? Does it contain mostly northern hardwoods - that is, beech, birch, maple, and ash, with some hemlock and spruce? If the answers to these two questions are "yes," then you may be interested in the work that is carried on at the Bartlett Experimental Forest in New Hampshire. This is one of the field laboratories established by the U. S....

  2. Efficient silvicultural practices for eastern hardwood management

    Science.gov (United States)

    Gary W. Miller; John E. Baumgras

    1994-01-01

    Eastern hardwood forests are now managed to meet a wide range of objectives, resulting in the need for silvicultural alternatives that provide timber, wildlife, aesthetics, recreation, and other benefits. However, forest management practices must continue to be efficient in terms of profiting from current harvests, protecting the environment, and sustaining production...

  3. Sampling the quality of hardwood trees

    Science.gov (United States)

    Adrian M. Gilbert

    1959-01-01

    Anyone acquainted with the conversion of hardwood trees into wood products knows that timber has a wide range in quality. Some trees will yield better products than others. So, in addition to rate of growth and size, tree values are affected by the quality of products yielded.

  4. Chapter 10:Hardwoods for timber bridges

    Science.gov (United States)

    James P. Wacker; Ed T. Cesa

    2005-01-01

    This chapter describes the joint efforts of the Forest Service and the FHWA to administer national programs including research, demonstration bridges, and technology transfer components. Summary information on a number of Forest Service-WIT demonstration bridges constructed with hardwoods is also provided.

  5. Proceedings, 15th central hardwood forest conference

    Science.gov (United States)

    David S. Buckley; Wayne K. Clatterbuck; [Editors

    2007-01-01

    Proceedings of the 15th central hardwood forest conference held February 27–March 1, 2006, in Knoxville, TN. Includes 86 papers and 30 posters pertaining to forest health and protection, ecology and forest dynamics, natural and artificial regeneration, forest products, wildlife, site classification, management and forest resources, mensuration and models, soil and...

  6. Proceedings 19th Central Hardwood Forest Conference

    Science.gov (United States)

    John W. Groninger; Eric J. Holzmueller; Clayton K. Nielsen; Daniel C., eds. Dey

    2014-01-01

    Proceedings from the 2014 Central Hardwood Forest Conference in Carbondale, IL. The published proceedings include 27 papers and 47 abstracts pertaining to research conducted on biofuels and bioenergy, forest biometrics, forest ecology and physiology, forest economics, forest health including invasive species, forest soils and hydrology, geographic information systems,...

  7. Automation for Primary Processing of Hardwoods

    Science.gov (United States)

    Daniel L. Schmoldt

    1992-01-01

    Hardwood sawmills critically need to incorporate automation and computer technology into their operations. Social constraints, forest biology constraints, forest product market changes, and financial necessity are forcing primary processors to boost their productivity and efficiency to higher levels. The locations, extent, and types of defects found in logs and on...

  8. Stocking chart for upland central hardwoods

    Science.gov (United States)

    Martin E. Dale; Donald E. Hilt

    1989-01-01

    The upland hardwoods stocking chart, introduced by Gingrich in 1967, has become one of the forest manager's most useful tools. The chart allows you to determine the condition of the present stand in relation to a stocking standard. The stocking of a stand is extremely helpful in prescribing various silvicultural treatments such as intermediate thinnings,...

  9. Harvesting systems for the northern forest hardwoods

    Science.gov (United States)

    Chris B. LeDoux

    2011-01-01

    This monograph is a summary of research results and environmental compliance measures for timber harvesting operations. Data are presented from the Northern Research Station's forest inventory and analysis of 20 states in the northern forest hardwoods. Harvesting systems available in the region today are summarized. Equations for estimating harvesting costs are...

  10. Defining Hardwood Veneer Log Quality Attributes

    Science.gov (United States)

    Jan Wiedenbeck; Michael Wiemann; Delton Alderman; John Baumgras; William Luppold

    2004-01-01

    This publication provides a broad spectrum of information on the hardwood veneer industry in North America. Veneer manufacturers and their customers impose guidelines in specifying wood quality attributes that are very discriminating but poorly defined (e.g., exceptional color, texture, and/or figure characteristics). To better understand and begin to define the most...

  11. Bottomland hardwood afforestation: State of the art

    Science.gov (United States)

    Emile S. Gardiner; D. Ramsey Russell; Mark Oliver; Lamar C. Dorris

    2000-01-01

    Over the past decade, land managers have implemented large-scale afforestation operations across the Southern United States to rehabilitate agricultural land historically converted from bottomland hardwood forest cover types. These afforestation efforts were initially concentrated on public land managed by State or Federal Government agencies, but have later shifted...

  12. Applying group selection in upland hardwoods

    Science.gov (United States)

    Gary w. Miller; H. Clay Smith

    1991-01-01

    Interest in applying group selection in upland hardwoods has grown in recent years, primarily in response to public opposition to the aesthetic effects of clearcutting. Critics suggest that an uneven-aged silvicultural practice such as group selection might be a suitable compromise--drastically reducing negative visual effects of harvesting trees while continuing to...

  13. Mycorrhization of containerised Pinus nigra seedlings with Suillus granulatus under open field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, J.; Keca, N.; Martinovie, A.

    2012-07-01

    Seedling mycorrhization acts as an efficient tool for improving the quality of seedlings. In this study, the effectiveness of Suillus granulatus, originating from Pinus heldreichii forests (Montenegro), to produce containerized ectomycorrhizal seedlings of autochthonous Pinus nigra in open field conditions was investigated. Spore (106, 107, 108) and vegetative (1:16, 1:8, 1:4) inoculation on ectomycorrhizal formation and seedling growth were tested. Spore and vegetative inoculums of autochthonous Pisolithus arhizus were used in the same trial as additional control treatments. The utilization of vegetative and spore inoculums of autochthonous S. granulatus has proven to be an effective method of obtaining containerized ectomycorrhizal P. nigra seedlings under open field conditions after 11 months. S. granulatus spore inoculations resulted in well developed ectomycorrhiza, decreasing the growth of the P. nigra seedlings in the first growing season. Mycelial inoculations resulted in slightly developed S. granulatus ectomycorrhiza, which increased the growth of the seedlings. Therefore, it would be feasible to use spore inocula of S. granulatus, with 10{sup 6} spores per plant, to produce ectomycorrhizal P. nigra plants on a large scale. Controlled mycorrhizal inoculation of seedlings is not a common practice in Montenegrin and Serbian nurseries; as such, the obtained results will contribute to the enhancement of nursery production of Pinus nigra and other conifers. This also could be assumed as a starting point for many further efforts and investigations with autochthonous fungal and plant material in this region. (Author) 47 refs.

  14. Melatonin Has the Potential to Alleviate Cinnamic Acid Stress in Cucumber Seedlings

    Directory of Open Access Journals (Sweden)

    Juanqi Li

    2017-07-01

    Full Text Available Cinnamic acid (CA, which is a well-known major autotoxin secreted by the roots in cucumber continuous cropping, has been proven to exhibit inhibitory regulation of plant morphogenesis and development. Melatonin (MT has been recently demonstrated to play important roles in alleviating plant abiotic stresses. To investigate whether MT supplementation could improve cucumber seedling growth under CA stress, we treated cucumber seeds and seedlings with/without MT under CA- or non-stress conditions, and then tested their effects on cucumber seedling growth, morphology, nutrient element content, and plant hormone. Overall, 10 μM MT best rescued cucumber seedling growth under 0.4 mM CA stress. MT was found to alleviate CA-stressed seedling growth by increasing the growth rates of cotyledons and leaves and by stimulating lateral root growth. Additionally, MT increased the allocation of newly gained dry weight in roots and improved the tolerance of cucumber seedlings to CA stress by altering the nutrient elements and hormone contents of the whole plant. These results strongly suggest that the application of MT can effectively improve cucumber seedling tolerance to CA stress through the perception and integration of morphology, nutrient element content and plant hormone signaling crosstalk.

  15. Effect of specific plant-growth-promoting rhizobacteria (PGPR) on growth and uptake of neonicotinoid insecticide thiamethoxam in corn (Zea mays L.) seedlings.

    Science.gov (United States)

    Myresiotis, Charalampos K; Vryzas, Zisis; Papadopoulou-Mourkidou, Euphemia

    2015-09-01

    Corn (Zea mays L.) is one of the most important cereal crops in the world and is used for food, feed and energy. Inoculation with plant-growth-promoting rhizobacteria (PGPR) would reduce the use of chemical fertilisers and pesticides and could be suggested as an alternative practice for sustainable production of corn in modern agricultural systems. In this study, the effect of two Bacillus PGPR formulated products, Companion (B. subtilis GB03) and FZB24 (B. subtilis FZB24), on corn growth and root uptake of insecticide thiamethoxam was investigated. All bacterial treatments enhanced root biomass production by 38-65% compared with the uninoculated control, with no stimulatory effect of PGPR on above-ground biomass of corn. The uptake results revealed that, in plants inoculated with the PGPR B. subtilis FZB24 and B. subtilis GB03, singly or in combination, the uptake and/or systemic translocation of thiamethoxam in the above-ground corn parts was significantly higher at the different growth ages compared with the control receiving no bacterial treatment. The findings suggest that the PGPR-elicited enhanced uptake of thiamethoxam could lead to improved efficiency of thiamethoxam using reduced rates of pesticides in combination with PGPR as an alternative crop protection technique. © 2014 Society of Chemical Industry.

  16. Effects of Copper-based Compounds, Antibiotics and a Plant Activator on Population Sizes and Spread of Clavibacter michiganensis subsp. michiganensis in Greenhouse Tomato Seedlings

    Directory of Open Access Journals (Sweden)

    Svetlana Milijašević

    2009-01-01

    Full Text Available Three copper-based compounds (copper hydroxide, copper oxychloride, copper sulphate, two antibiotics (streptomycin and kasugamycin and a plant activator (ASM significantly reduced population sizes and spread of C. michiganensis subsp. michiganensis among tomatoseedlings in the greenhouse. Streptomycin had the best effect in reducing pathogen population size in all sampling regions. Moreover, this antibiotic completely stopped the spread of C. michiganensis subsp. michiganensis in the region most distant from the inoculumfocus. Copper hydroxide mixed with streptomycin significantly limited the pathogen population, compared with copper hydroxide alone, the other copper-based compounds, ASM and kasugamycin. However, combining streptomycin with copper hydroxide did notcontribute to its greater efficacy against the pathogen population. Copper-based compounds, in general, were less effective in limiting pathogen population sizes than the other treatments in all three sampling regions, primarily copper oxychloride and the combinationof copper hydroxide and mancozeb. Among copper compounds, copper hydroxide was the most prominent in reducing the bacterial population, especially in the region closest to the inoculum focus, while its combination with mancozeb did not improve the effects. Kasugamycin significantly limited pathogen population size, compared to copper bactericides, but it was less effective than the other antibiotic compound, i.e. streptomycin. The plant activator ASM significantly reduced population density, and it was more effectivewhen used three days prior to inoculation than six days before inoculation.

  17. Comparative study of drought and salt stress effects on germination and seedling growth of pea

    Directory of Open Access Journals (Sweden)

    Petrović Gordana

    2016-01-01

    Full Text Available Seed germination is first critical and the most sensitive stage in the life cycle of plants compromise the seedlings establishment. Salt and drought tolerance testing in initial stages of plant development is of vital importance, because the seed with more rapid germination under salt or water deficit conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields. The aim of this study was to determine whether the pea seed germination and seedling growth were inhibited by the salt toxicity and osmotic effect during the seedling development, and also identification of the sensitive seedling growth parameters in response to those stresses. Based on the obtained results, pea has been presented to be more tolerant to salt than water stress during germination and early embryo growth. Investigated cultivars showed greater susceptibility to both abiotic stresses when it comes growth parameters compared to seed germination. [Projekat Ministarstva nauke Republike Srbije, br. TR-31024 i br. TR-31022

  18. Growth of young Tabebuia aurea seedlings under irrigation with wastewater from fish farming

    Directory of Open Access Journals (Sweden)

    José R. de S. Pinto

    2016-06-01

    Full Text Available ABSTRACT This study aimed to evaluate the growth of young Tabebuia aurea seedlings irrigated with different concentrations of wastewater from fish farming. The experiment was conducted in a seedling nursery, from June to August 2013. The treatments consisted of five concentrations of wastewater from fish farming diluted in freshwater (0, 25, 50, 75 and 100% of wastewater. Plant height, stem diameter and plant height/stem diameter ratio were evaluated every 15 days to verify the effects of treatments on seedlings growth. At the end of the experiment, individual leaf area, leaf area, leaf dry matter, stem dry matter, root dry matter, total dry matter and Dickson quality index were also evaluated. The reuse of wastewater from fish farming diluted at concentrations of 25 and 50% in freshwater is a viable alternative in the production of Tabebuia aurea seedlings. However, higher concentrations hinder the production of seedlings of this species.

  19. Radiation effects on Brassica seeds and seedlings

    Science.gov (United States)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  20. Light-emitting diode lighting for forest nursery seedling production

    Science.gov (United States)

    R. Kasten Dumroese; Jeremiah R. Pinto; Anthony S. Davis

    2015-01-01

    Crop lighting is an energy-intensive necessity for nursery production of high-quality native plants and forest tree seedlings. During the winter months (especially in northern USA latitudes) or overcast or cloudy days, the amount of solar radiation reaching greenhouse crops is insufficient resulting in growth cessation, early terminal bud formation, and failure of...

  1. Glyoxalase I expression pattern in Hevea brasiliensis seedlings ...

    African Journals Online (AJOL)

    Glyoxalase I expression pattern in Hevea brasiliensis seedlings under varied stress conditions. MVP Siraj, A Thulaseedharan, Anu Augustine. Abstract. Drought is one of the most important stress factors which adversely affect plants' growth and productivity. Global climate change may make this situation more serious in the ...

  2. Simulated drought influences oxidative stress in Zea mays seedlings ...

    African Journals Online (AJOL)

    Drought is an abiotic factor that limits the productivity of crop plants survival and productivity. This study was conducted to evaluate the effects of simulated drought on the malondialdehyde (MDA) and antioxidant enzymes activity in Zea mays. Seedlings were grown for 8 weeks in nursery bags filled with sandy-loam soil in ...

  3. Height suppression of tomato plug seedlings by an environment ...

    African Journals Online (AJOL)

    Experiments were conducted to investigate appropriate concentrations of plant growth retardants (PGRs) and duration of seed soaking in order to suppress hypocotyl length and plug seedling height of 2 tomato cultivars ( Lycopersicum esculentum Mill. cv. Seogeon and Seokwang). Daminozide (B-9), uniconazole ...

  4. Cold stratification, but not stratification in salinity, enhances seedling ...

    African Journals Online (AJOL)

    Cold stratification, but not stratification in salinity, enhances seedling growth of wheat under salt treatment. L Wang, HL Wang, CH Yin, CY Tian. Abstract. Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. Experiments were conducted to test the hypothesis that cold ...

  5. Gene activity test determines cold tolerance in Douglas-fir seedlings

    Science.gov (United States)

    Peter A. Balk; Diane L. Haase; Monique F. van Wordragen

    2008-01-01

    Forest tree nurseries rely on a tight scheduling of operations to be able to deliver vigorous seedlings to the planting site. Cooler or freezer storage is often used to maintain planting stock in an inactive condition and to ensure a plant supply for geographically diverse planting sites, which is a requirement for large-scale or internationally operating nurseries....

  6. Repetitive Reaction and Restitution (R3) induction of drought hardiness in conifer container seedlings

    Science.gov (United States)

    Jol Hodgson

    2011-01-01

    Planting failures are often attributed to unexpectedly harsh conditions after planting. Characterization of soil water at the planting site, along with associated influences of site preparation and soil texture, is recommended. Additionally, tree planting technique and seedling biology should be targeted to site conditions. A nursery regime for induction of drought...

  7. Bacillus amyloliquefaciens L-S60 Reforms the Rhizosphere Bacterial Community and Improves Growth Conditions in Cucumber Plug Seedling

    Directory of Open Access Journals (Sweden)

    Yuxuan Qin

    2017-12-01

    Full Text Available Vegetable plug seedling has become the most important way to produce vegetable seedlings in China. This seedling method can significantly improve the quality and yield of vegetables compared to conventional methods. In the process of plug seedling, chemical fertilizers or pesticides are often used to improve the yield of the seedlings albeit with increasing concerns. Meanwhile, little is known about the impact of beneficial bacteria on the rhizosphere microbiota and the growth conditions of vegetables during plug seedling. In this study, we applied a culture-independent next-generation sequencing-based approach and investigated the impact of a plant beneficial bacterium, Bacillus amyloliquefaciens L-S60, on the composition and dynamics of rhizosphere microbiota and the growth conditions of cucumbers during plug seedling. Our results showed that application of L-S60 significantly altered the structure of the bacterial community associated with the cucumber seedling; presence of beneficial rhizosphere species such as Bacillus, Rhodanobacter, Paenibacillus, Pseudomonas, Nonomuraea, and Agrobacterium was higher upon L-S60 treatment than in the control group. We also measured the impact of L-S60 application on the physiological properties of the cucumber seedlings as well as the availability of main mineral elements in the seedling at different time points during the plug seedling. Results from those measurements indicated that L-S60 application promoted growth conditions of cucumber seedlings and that more available mineral elements were detected in the cucumber seedlings from the L-S60 treated group than from the control group. The findings in this study provided evidence for the beneficial effects of plant growth-promoting rhizosphere bacteria on the bacterial community composition and growth conditions of the vegetables during plug seedling.

  8. Juglone effects on seedling growth in intact and coatless seeds of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... Key words: Juglone, muskmelon, seedling growth, protein content, polyphenol oxidase activity. INTRODUCTION ... Juglone has been isolated from many plants in the .... In pea seeds, a relation between PPO activity and seed.

  9. Effects of Different Ectomycorrhizal Fungal Inoculates on the Growth of Pinus tabulaeformis Seedlings under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2016-12-01

    Full Text Available The tree species Pinus tabulaeformis Carr. (P. tabulaeformis is commonly planted in China due to its economic and ecological value. In order to identify one or more ectomycorrhizal (ECM fungal species for future P. tabulaeformis afforestation, we investigated the effects of five ECM fungal species: Laccaria laccata, Boletus edulis, Gomphidius viscidus, Suillus grevillei, and Suillus luteus on the growth of P. tabulaeformis seedlings under greenhouse conditions. The growth parameters of P. tabulaeformis seedlings were evaluated 90 days following fungal colonisation. The majority of seedlings were significantly affected by ECM inoculation. Mycorrhizal inoculated seedlings were taller, had more lateral roots, and a greater biomass compared with the non-mycorrhizal (CK seedlings. With the exception of G. viscidus, inoculated seedlings exhibited higher phosphorus, potassium, and nitrogen content compared with the CK seedlings. In addition, ECM colonisation increased the enzymatic activity of catalase, acidic phosphatase, protease, and the urease content in the rhizosphere soil. Our study showed that Laccaria laccata, Suillus grevillei, and Suillus luteus may be useful for improving the growth and cultivation of P. tabulaeformis seedlings. Furthermore, we observed that S. luteus inoculation increased the gas exchange parameters of P. tabulaeformis seedlings under field conditions.

  10. SOURCES OF MYCORRHIZAL INFECTION OF SHOREA ACUMINATA SEEDLINGS UNDER LABORATORY CONDITIONS

    Directory of Open Access Journals (Sweden)

    LEE Su SEE

    1995-01-01

    Full Text Available Uninoculated dipterocarp seedlings raised in normal field soil in nurseries were always found to have mycorrhizas after a few months. This study set out to determine whether dipterocarp seedlings could continue to grow and develop in the absence of mycorrhizas and also to determine possible sources of mycorrhizal infection of dipterocarp seedlings raised under laboratory conditions using Shorea acuminata as a typical example. Seedlings were planted in capped or uncapped perspex boxes containing sterile or non-sterile field soil and watered daily with sterile water or tap water. Seedling growth and development of mycorrhizas were monitored at monthly intervals for up to seven months. Seedlings grown in sterile soil remained uninfected after seven months while infection was found in some of the seedlings grown in normal soil regardless of whether they had been watered with tap water or sterile water. This showed that field soil (i.e. under grass far from the forest contained suitable inoculum for forest tree seedlings. Tap water and the air were not important sources of infection. However, mycorrhizal infection was very uneven indicating that the inoculum was probably very unevenly distributed in the soil or that the inoculum density was rather low. Seedlings grown in sterile soil showed better growth than those grown in normal soil and infection of roots by parasitic fungi in the latter was also observed.

  11. Arbuscular Mycorrhizal Symbiosis Modulates Antioxidant Response and Ion Distribution in Salt-Stressed Elaeagnus angustifolia Seedlings

    Directory of Open Access Journals (Sweden)

    Wei Chang

    2018-04-01

    Full Text Available Elaeagnus angustifolia L. is a drought-resistant species. Arbuscular mycorrhizal symbiosis is considered to be a bio-ameliorator of saline soils that can improve salinity tolerance in plants. The present study investigated the effects of inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis on the biomass, antioxidant enzyme activities, and root, stem, and leaf ion accumulation of E. angustifolia seedlings grown during salt stress conditions. Salt-stressed mycorrhizal seedlings produced greater root, stem, and leaf biomass than the uninoculated stressed seedlings. In addition, the seedlings colonized by R. irregularis showed notably higher activities of superoxide dismutase (SOD, catalase (CAT, and ascorbate peroxidase (APX in the leaves of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Mycorrhizal seedlings not only significantly increased their ability to acquire K+, Ca2+, and Mg2+, but also maintained higher K+:Na+ ratios in the leaves and lower Ca2+:Mg2+ ratios than non-mycorrhizal seedlings during salt stress. These results suggest that the salt tolerance of E. angustifolia seedlings could be enhanced by R. irregularis. The arbuscular mycorrhizal symbiosis could be a promising method to restore and utilize salt-alkaline land in northern China.

  12. Arbuscular Mycorrhizal Symbiosis Modulates Antioxidant Response and Ion Distribution in Salt-Stressed Elaeagnus angustifolia Seedlings.

    Science.gov (United States)

    Chang, Wei; Sui, Xin; Fan, Xiao-Xu; Jia, Ting-Ting; Song, Fu-Qiang

    2018-01-01

    Elaeagnus angustifolia L. is a drought-resistant species. Arbuscular mycorrhizal symbiosis is considered to be a bio-ameliorator of saline soils that can improve salinity tolerance in plants. The present study investigated the effects of inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis on the biomass, antioxidant enzyme activities, and root, stem, and leaf ion accumulation of E. angustifolia seedlings grown during salt stress conditions. Salt-stressed mycorrhizal seedlings produced greater root, stem, and leaf biomass than the uninoculated stressed seedlings. In addition, the seedlings colonized by R. irregularis showed notably higher activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in the leaves of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Mycorrhizal seedlings not only significantly increased their ability to acquire K + , Ca 2+ , and Mg 2+ , but also maintained higher K + :Na + ratios in the leaves and lower Ca 2+ :Mg 2+ ratios than non-mycorrhizal seedlings during salt stress. These results suggest that the salt tolerance of E. angustifolia seedlings could be enhanced by R. irregularis. The arbuscular mycorrhizal symbiosis could be a promising method to restore and utilize salt-alkaline land in northern China.

  13. Quality assessment of truffle-inoculated seedlings in Italy: proposing revised parameters for certification

    Directory of Open Access Journals (Sweden)

    Domizia Donnini

    2014-08-01

    Full Text Available Aim of study: the main aims of this study were to evaluate the quality of truffle-inoculated seedlings produced by commercial nurseries in Italy and to identify their minimum requisites in terms of plant age, health, homogeneity, and cut-off percentage of inoculated Tuber and non-Tuber ectomycorrhizae, based on the analysis of an extensive sample of seedlings subjected to quality control and certification.Area of study: truffle-inoculated seedlings produced by Italian commercial nurseries.Material and Methods: analysis of truffle-inoculated seedlings for health and quality standards; recording of presence of inoculated Tuber spp. and other concurrent fungi according to the official Italian method for certification; selective amplification of ectomycorrhizal DNA by PCR species-specific primers.Main results: We showed that mycorrhization levels in truffle-inoculated seedlings increased with time after truffle-spore inoculation. The highest mean percentage of the inoculated Tuber spp., but also the highest presence of contaminants, were recorded after three years. The mycorrhization level of Tuber melanosporum and T. aestivum was higher in Corylus and Ostrya seedlings than in Q. ilex and Q. pubescens, but the latter two host species showed the lowest presence of other ectomycorrhizal fungi. Mycorrhization level distribution in truffle-inoculated seedlings of suitable batches differed very little from the distribution in only all suitable seedlings. Truffle seedlings with other Tuber spp. were very few and even absent after three years. The general quality of Italian truffle-inoculated seedlings is high but can be improved even further by revising the parameters used for their certification.Research highlights: Mycorrhization assessment in truffle-inoculated seedlings produced by commercial nurseries and a revision of the parameters of quality standards following several years of certification in Italy.Keywords: Truffle cultivation; truffle

  14. Effect of CO2 Enrichment on the Growth and Nutrient Uptake of Tomato Seedlings

    Institute of Scientific and Technical Information of China (English)

    LI Juan; ZHOU Jian-Min; DUAN Zeng-Qiang; DU Chang-Wen; WANG Huo-Yan

    2007-01-01

    Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (360 or 720 μL L-1), and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age),and the seedling vigor index (seedling vigor index = stem thickness/(plant height × total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.

  15. Variation in experimental flood impacts and ecogeomorphic feedbacks among native and exotic riparian tree seedlings

    Science.gov (United States)

    Kui, L.; Stella, J. C.; Skorko, K.; Lightbody, A.; Wilcox, A. C.; Bywater-Reyes, S.

    2012-12-01

    Flooding interacts with riparian plants on a variety of scales, resulting in coevolution of geomorphic surfaces with plant vegetation communities. Our research aims to develop a mechanistic understanding of riparian seedling damage from small floods, with a focus on differential responses among species (native and non-native), ecogeomorphic feedbacks, and implications for riparian restoration. We tested the effects of controlled flood events on cottonwood (Populus fremontii) and tamarisk (Tamarix spp.) seedlings in an experimental meandering stream channel. We hypothesized that seedling dislodgement and burial would be influenced by individual plant height, species-specific morphology, patch density, and differences in hydraulic forces (as a function of location on the bar). Four experimental floods were tested, with different combinations of plant species and seedling densities. For each flood run, rooted seedlings were installed within a 1.5-m-wide sandbar during low flow conditions and stream discharge was increased to a constant flood level for approximately 8 hours, after which seedling response was assessed. Seedling damage was analyzed within a logistic regression framework that predicted the probability of dislodgement or burial as a function of the explanatory variables. Plant dislodgement depended on root length and the location on the sandbar, whereas burial depended on plant height, species-specific morphology, and location. For every centimeter increase in plant height, the odds of plant burial decreased by 10 percent, illustrating the rate at which plants developed flood resistance as they grow taller. With every meter closer to the thalweg, plant dislodgement was four times more likely, and plant burial was 2.6 times more likely. The probability of burial was twice as great for tamarisk seedlings as for cottonwood. The increased sedimentation within tamarisk patches was associated with a denser foliage and a more compact crown for this species. The

  16. Effects of Azospirillum lipoferum on seedling characteristics derived from sunflower (Helianthus annus L. seed water deficit conditions

    Directory of Open Access Journals (Sweden)

    H. Hadi

    2016-05-01

    Full Text Available Seedling characteristics of different sunflower (Helianthus annus L. cultivars under drought stress and inoculation with the Azospirillum lipoferum in a spilt-factorial layout based on randomized complete block design with three replications were evaluated. Treatments included dehydration stress (seed produced on maternal plants which irrigated after 60 (desirable irrigation, 120 (medium stress, 180 mm (severe stress evaporation from evaporation pan class A, different sunflower cultivars (Lakomka, Master, Favorite, Soor and Armavirosky and inoculation with bacteria (Azospirillum lipoferum and control. Bacteria allocated in the main plots and seeds which derived from dehydration stress conditions and different cultivars were allocated in sub plots as a factorial layout. Results showed that the time of seedling emergence, seedling vigor index, leaf petiole, stem and seedling dry weight were increased 14, 44, 30, 31, 22 and 27 percent by inoculating with bacteria, respectively. The percent of Seedling emergence of seeds derived from medium stress 48 percent was more than optimal irrigation conditions. Final appearance, speed of emergence, emergence index, dry weight and stamina seedling resulting from severe stress conditions were decreased compared with optimal irrigation. Seedling emergence of seeds derived from medium stress which inoculated with bacteria increased by 9 percent. Emergence speed index, appearance, stamina and seedling dry weights of seeds which inoculated with bacteria increased at medium and sever water stress. With consideration of the effect of dehydration stress on germination and seedling emergence, seed inoculation with bacteria improved seedling emergence and seedling vigor of seeds derived from dehydration stress conditions.

  17. METHYL JASMONATE AND STEM BENDING HARDENING AND INITIAL GROWTH OF Cordia trichotoma SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Danielle Acco Cadorin

    2015-12-01

    Full Text Available The submission of seedlings to mechanical stimuli and plant growth regulator promote their hardening and can be included in the routine of nurseries, favoring the survival and initial growth in the field. The study aimed to evaluate the effects of applying methyl jasmonate and stem bending in hardening and initial growth of Cordia trichotoma seedlings. Seedlings were subjected to 20 stem bending daily for 4 weeks; 20 stem bending daily for 8 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 4 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 8 weeks and the control treatment. The design was a completely randomized, with five repetitions of the fourteen seedlings. Seedlings submitted to hardening treatments showed less increment in height, greater increment in stem diameter and less value for strength index. Seedlings of control treatment had greater loss of root tissue electrolytes and less potential for root regeneration. In the field, 180 days after planting, seedlings submitted to eight weeks of stem bending and eight methyl jasmonate applications showed greater increment in height and stem diameter. The results indicate that both stem bending such as methyl jasmonate application for eight weeks are effective in promoting hardening and improve the starting performance in field of Cordia trichotoma seedlings.

  18. Changes in faunal and vegetation communities along a soil calcium gradient in northern hardwood forests

    Science.gov (United States)

    Beier, Colin M.; Woods, Anne M.; Hotopp, Kenneth P.; Gibbs, James P.; Mitchell, Myron J.; Dovciak, Martin; Leopold, Donald J.; Lawrence, Gregory B.; Page, Blair D.

    2012-01-01

    Depletion of Ca from forest soils due to acidic deposition has had potentially pervasive effects on forest communities, but these impacts remain largely unknown. Because snails, salamanders, and plants play essential roles in the Ca cycle of northern hardwood forests, we hypothesized that their community diversity, abundance, and structure would vary with differences in biotic Ca availability. To test this hypothesis, we sampled 12 upland hardwood forests representing a soil Ca gradient in the Adirondack Mountains, New York (USA), where chronic deposition has resulted in acidified soils but where areas of well-buffered soils remain Ca rich due to parent materials. Along the gradient of increasing soil [Ca2+], we observed increasing trends in snail community richness and abundance, live biomass of redback salamanders (Plethodon cinereus (Green, 1818)), and canopy tree basal area. Salamander communities were dominated by mountain dusky salamanders (Desmognathus ochrophaeus Cope, 1859) at Ca-poor sites and changed continuously along the Ca gradient to become dominated by redback salamanders at the Ca-rich sites. Several known calciphilic species of snails and plants were found only at the highest-Ca sites. Our results indicated that Ca availability, which is shaped by geology and acidic deposition inputs, influences northern hardwood forest ecosystems at multiple trophic levels, although the underlying mechanisms require further study.

  19. Plants' responses to drought and shade environments

    African Journals Online (AJOL)

    전병기

    factors affect plants' growth, morphology, physiology and biochemistry. Many research works .... Hardwood and Conifer tree species n central Wisconsin: Influence of light regime and .... Ecotypic variation in response to light spectra in Scots ...

  20. A Predictive Coexpression Network Identifies Novel Genes Controlling the Seed-to-Seedling Phase Transition in Arabidopsis thaliana.

    Science.gov (United States)

    Silva, Anderson Tadeu; Ribone, Pamela A; Chan, Raquel L; Ligterink, Wilco; Hilhorst, Henk W M

    2016-04-01

    The transition from a quiescent dry seed to an actively growing photoautotrophic seedling is a complex and crucial trait for plant propagation. This study provides a detailed description of global gene expression in seven successive developmental stages of seedling establishment in Arabidopsis (Arabidopsis thaliana). Using the transcriptome signature from these developmental stages, we obtained a coexpression gene network that highlights interactions between known regulators of the seed-to-seedling transition and predicts the functions of uncharacterized genes in seedling establishment. The coexpressed gene data sets together with the transcriptional module indicate biological functions related to seedling establishment. Characterization of the homeodomain leucine zipper I transcription factor AtHB13, which is expressed during the seed-to-seedling transition, demonstrated that this gene regulates some of the network nodes and affects late seedling establishment. Knockout mutants for athb13 showed increased primary root length as compared with wild-type (Columbia-0) seedlings, suggesting that this transcription factor is a negative regulator of early root growth, possibly repressing cell division and/or cell elongation or the length of time that cells elongate. The signal transduction pathways present during the early phases of the seed-to-seedling transition anticipate the control of important events for a vigorous seedling, such as root growth. This study demonstrates that a gene coexpression network together with transcriptional modules can provide insights that are not derived from comparative transcript profiling alone. © 2016 American Society of Plant Biologists. All Rights Reserved.

  1. Growth and ABA responses of maple seedlings to aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, A.; Robitaille, G.; Boutin, R. [Canadian Forestry Service, Sainte Foy, PQ (Canada); Nadeau, P. [Agriculture and Agri-Food Canada Research Station, Sainte-Foy, PQ (Canada)

    1995-12-01

    The impacts of low pH and 2.0 mM aluminum (Al) on the growth of sugar maple seedlings was assessed over a 13-week period. The hypothesis was that low pH and high aluminum concentration would lower the vigor of sugar maple seedlings and were contributing factors to sugar maple stand decline. The effects of the stresses were measured in roots and shoots. The concentration of abscisis acid (ABA) in xylem sap in response to Al over time was measured to determine whether it could be used as an indicator of Al stress in sugar maple seedlings. At week 9, total leaf area of Al-treated seedlings was reduced by 27%, but by week 13 leaf area was similar for seedlings in all treatments. None of the other growth parameters examined were negatively affected by the treatments at either week 9 or week 13. ABA concentration in the xylem sap was not affected by any of the treatments. The duration of exposure to Al was found critical when assessing a threshold concentration for Al toxicity because plants can acclimate to an Al concentration previously considered toxic. 36 refs., 1 tab., 6 figs.

  2. Symbiotic propagation of seedlings of Cyrtopodium glutiniferum Raddi (Orchidaceae

    Directory of Open Access Journals (Sweden)

    Fernanda Aparecida Rodrigues Guimarães

    2013-09-01

    Full Text Available In nature, orchid seeds obtain the nutrients necessary for germination by degrading intracellular fungal structures formed after colonization of the embryo by mycorrhizal fungi. Protocols for asymbiotic germination of orchid seeds typically use media with high concentrations of soluble carbohydrate and minerals. However, when reintroduced into the field, seedlings obtained via asymbiotic germination have lower survival rates than do seedlings obtained via symbiotic germination. Tree fern fiber, the ideal substrate for orchid seedling acclimatization, is increasingly scarce. Here, we evaluated seed germination and protocorm development of Cyrtopodium glutiniferum Raddi cultivated in asymbiotic media (Knudson C and Murashige & Skoog and in oatmeal agar (OA medium inoculated with the mycorrhizal fungus Epulorhiza sp., using non-inoculated OA medium as a control. We also evaluated the performance of tree fern fiber, pine bark, eucalyptus bark, corncob and sawdust as substrates for the acclimatization of symbiotically propagated plants. We determined germination percentages, protocorm development and growth indices at 35 and 70 days of cultivation. Relative growth rates and the effects of substrates on mycorrhizal formation were calculated after 165 days of cultivation. Germination efficiency and growth indices were best when inoculated OA medium was used. Corncob and pine bark showed the highest percentages of colonized system roots. The OA medium inoculated with Epulorhiza sp. shows potential for C. glutiniferum seedling production. Corncob and pine bark are promising substitutes for tree fern fiber as substrates for the acclimatization of orchid seedlings.

  3. Study on tissue culture for Gelidium seedling

    Science.gov (United States)

    Pei, Lu-Qing; Luo, Qi-Jun; Fei, Zhi-Qing; Ma, Bin

    1996-06-01

    As seedling culture is a crucial factor for successful cultivation of Gelidium, the authors researched tissue culture technology for producing seedlings. The morphogeny and experimental ecology were observed and studied fully in 2 5 mm isolated tissue fragments. Regeneration, appearance of branching creepers and attaching structure and new erect seedlings production and development were studied. Fragments were sown on bamboo slice and vinylon rope. The seedlings were cultured 20 30 days indoor, then cultured in the sea, where the density of erect seedlings was 3 19 seedlings/cm2, growth rate was 3.84% day. The frond arising from seedlings directly was up to 10 cm per year. The ecological conditions for regenerated seedlings are similar to the natural ones. The regenerated seedlings are suitable for raft culture in various sea areas.

  4. Germination and seedling establishment in orchids: a complex of requirements.

    Science.gov (United States)

    Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara

    2015-09-01

    Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several

  5. Information Sharing in the Hardwood Supply Chain

    OpenAIRE

    Stiess, Timothy Stephen

    2010-01-01

    The Hardwood Industry in United States has been challenged by low-cost competition from overseas. Although cost reduction strategies have had minimal success, the proximity of industry to the domestic market has large implications on a more customer-focused strategy. The problem arises that individual companies and supply chains evolved based on the principles of economies of size and not on the flexibility to adapt to customer needs and changing resource constraints. An increased rate at ...

  6. Effects of timber harvest on structural diversity and species composition in hardwood forests

    Directory of Open Access Journals (Sweden)

    FARZAM TAVANKAR

    2015-04-01

    Full Text Available Tavankar F, Bonyad AE. 2015. Effects of timber harvest on structural diversity and species composition in hardwood forests. Biodiversitas 16: 1-9. Forest management leads to changes in structure and species composition of stands. In this research vertical and horizontal structure and species composition were compared in two harvested and protected stands in the Caspian forest of Iran. The results indicated the tree and seedling density, total basal area and stand volume was significantly (P < 0.01 higher in the protected stand. The Fagus orientalis L. had the most density and basal area in the both stands. Species importance value (SIV of Fagus orientalis in the protected stand (92.5 was higher than in the harvested stand (88.5. While, the SIV of shade-intolerant tree species such as Acer insigne, Acer cappadocicum and Alnus subcordata was higher in the harvested stand. The density of trees and seedling of rare tree species, such as Ulmus glabra, Tilia begonifolia, Zelkova caprinifolia and Fraxinus coriarifolia, was also higher in the protected stand. The Shannon-Wiener diversity index in the protected stand (0.84 was significantly higher (P < 0.01 than in the harvested stand (0.72. The highest diversity value in the harvested stand was observed in DBH of 10-40 cm class, while DBH of 40-70 cm had the highest diversity value in the protected stand.

  7. Machine site preparation improves seedling performance on a high-elevation site in southwest Oregon

    International Nuclear Information System (INIS)

    McNabb, D.H.; Baker-Katz, K.; Tesch, S.D.

    1993-01-01

    Douglas-fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of four site-preparation treatments (scarify, scarify/till, soil removal, and soil removal/till) and on unprepared control areas were compared for 5 yr at a high-elevation, nutrient-poor site in the western Siskiyou Mountains of southwest Oregon. Fifth-year survival of seedlings was at least 85% among machine-prepared plots, compared to 42% on control plots. Cover of competing vegetation remained less than 25% during the period for all machine treatments. In contrast, vegetation cover on control plots was 30% at the time of planting and increased to nearly 75% after 5 yr. Competing vegetation clearly impeded seedling performance. The effects of unusually droughty conditions at the time of planting in 1982 were examined further by interplanting additional seedlings in the soil-removal treatment in 1985. The interplanting was followed by more normal spring precipitation, and seedlings grew better over 5 yr than those planted in 1982. The slow recovery of competing vegetation and generally poor seedling growth on all treatments during both planting years are attributed to low soil fertility

  8. Production and development of eucalyptus seedlings in function of doses of phosphorus

    Directory of Open Access Journals (Sweden)

    José Henrique Tertulino Rocha

    2013-12-01

    Full Text Available This study evaluated the effect of phosphorus (P on the survival in the nursery and early development in the field of clonal Eucalyptus urophylla x Eucalyptus grandis seedlings. The experimental design was completely randomized with four treatments and five replicates of 30 plants per replicate. At the end of the cycle (90 days, 15 seedlings were used for determining the dry matter accumulation and nutrient concentration in the shoot. The rest was planted in the field to determine the percentage of survival and early development. The treatments consisted of four doses of P fertilization (0.0, 1.3, 2.6 and 5.2 mg plant-1. To obtain high quality seedlings in conditions similar to this experiment it is required doses of P in the range from 3.6 to 3.8 mg plant-1. Doses greater than 4 mg plant-1 affect the development and quality of eucalyptus seedlings. An adequate phosphorus fertilization of eucalyptus seedlings increase, by about 30%, the percentage of surviving seedlings in the field.

  9. Potential production of Aspidosperma cylindrocarpon seedlings viarescue seedlings

    Directory of Open Access Journals (Sweden)

    Nathália Ferreira e Silva

    Full Text Available ABSTRACT: Translocation of rare populations is regarded as the last resort for the conservation of species whose habitat destruction is imminent. The objective of the present study was to evaluate the effect of two height classes and three leaf reduction intensities on growth and increases in height, stem diameter, survival, and new leaf production in seedlings of Aspidosperma cylindrocarpon (peroba obtained via rescue seedlings in a remnant of tropical semi deciduous forest. We recovered 240 individuals that were divided into two height classes (Class I-5 to 15cm and Class II-20 to 35cm and subjected to three leaf reduction intensities (0%, 50%, and 100%, which were then transported to a shade house with 50% light reduction. Measurements of height, stem diameter, and new leaf production were collected 8 times at 0, 15, 60, 75, 90, 105, 120, and 135 days, and survival rate was measured at day 135. The average survival rate was 82.9%; 77.5% for one Class I (5-15cm and 88.3% for Class II (20-35cm. Higher seedling growth was observed for the 0% leaf reduction treatment in both height classes. The leaves insertion were greater in the 100% cuts, with a decrease observed over time. It is advisable to restore A. cylindrocarpon seedlings in two height classes owing to the high survival rate, leaf appearance, and growth reported in the present study. The no-leaf reduction treatment (0% is the most viable alternative for the production of A. cylindrocarpon seedlings, via rescue seedlings.

  10. Researching effects of prescribed fire in hardwood forests

    Science.gov (United States)

    Stacy L. Clark; Kathleen E. Franzreb; Cathryn H. Greenberg; Tara Keyser; Susan C. Loeb; David L. Loftis; W. Henry McNab; Joy M. O' Keefe; Callie Jo Schweitzer; Martin Spetich

    2012-01-01

    The Upland Hardwood Ecology and Management Research Work Unit (RWU 4157) is a group of research teams located across the South, strategically placed to conduct research in physiographic sub-regions of the upland hardwood ecosystems including the southern Appalachian Mountains, the Cumberland Plateau, the Boston Mountains, and the Missouri Plateau. Our RWU is one of 16...

  11. An econometric model of the hardwood lumber market

    Science.gov (United States)

    William G. Luppold

    1982-01-01

    A recursive econometric model with causal flow originating from the demand relationship is used to analyze the effects of exogenous variables on quantity and price of hardwood lumber. Wage rates, interest rates, stumpage price, lumber exports, and price of lumber demanders' output were the major factors influencing quantities demanded and supplied and hardwood...

  12. Spectral reflectance of five hardwood tree species in southern Indiana

    Science.gov (United States)

    Dale R. Weigel; J.C. Randolph

    2013-01-01

    The use of remote sensing to identify forest species has been ongoing since the launch of Landsat-1 using MSS imagery. The ability to separate hardwoods from conifers was accomplished by the 1980s. However, distinguishing individual hardwood species is more problematic due to similar spectral and phenological characteristics. With the launch of commercial satellites...

  13. Match Your Hardwood Lumber to Current Market Needs

    Science.gov (United States)

    Robert J. Bush; Steven A. Sinclair; Philip A. Araman

    1990-01-01

    This article explains how hardwood lumber producers can best market their product. The study included four segments of the market for hardwood lumber. These segments were: furniture, cabinet, dimension and flooring, and molding/millwork manufacturers. The article explains how the study was conducted and the characteristics of companies (i.e., potential customers) that...

  14. Silvicultural guide for northern hardwoods in the northeast

    Science.gov (United States)

    William B. Leak; Mariko Yamasaki; Robbo. Holleran

    2014-01-01

    This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and...

  15. On Tour... Primary Hardwood Processing, Products and Recycling Unit

    Science.gov (United States)

    Philip A. Araman; Daniel L. Schmoldt

    1995-01-01

    Housed within the Department of Wood Science and Forest Products at Virginia Polytechnic Institute is a three-person USDA Forest Service research work unit (with one vacancy) devoted to hardwood processing and recycling research. Phil Araman is the project leader of this truly unique and productive unit, titled ãPrimary Hardwood Processing, Products and Recycling.ä The...

  16. Do region and gender influence hardwood product selection?

    Science.gov (United States)

    Delton Alderman

    2013-01-01

    Consumer preference is a fundamental focus of marketing research as it is used in developing marketing strategy and the positioning of products against competitors. This study evaluated consumer hardwood preferences of consumers from three United States geographical regions, which included six different metropolitan areas. Seven hardwood species and three laminate...

  17. Factors affecting regional changes in hardwood lumber production

    Science.gov (United States)

    William G. Luppold; Gilbert P. Dempsey; Gilbert P. Dempsey

    1994-01-01

    Hardwood lumber production increased by nearly 1.8 billion board feet between 1986 and 1990 and decreased sharply in 1991. However, not all areas of the country experienced the same growth in hardwood lumber production during the 1980s. While lumber production in inland regions of the eastern United States and the west increased during the 1980s, lumber output in...

  18. Hardwood lumber supply chain: current status and market opportunities

    Science.gov (United States)

    Urs Buehlmann; Matthew Bumgardner; Al Schuler; Mark Barford

    2007-01-01

    The membership of the Appalachian Hardwood Manufacturers Association was surveyed in 2005 to determine the current status of large Appalachian sawmills. The primary focus was to assess the impacts of globalization on primary manufacturing, but attention was also paid to general issues affecting the hardwood lumber supply chain-from concerns over forest health and log...

  19. A new tree classification system for southern hardwoods

    Science.gov (United States)

    James S. Meadows; Daniel A. Jr. Skojac

    2008-01-01

    A new tree classification system for southern hardwoods is described. The new system is based on the Putnam tree classification system, originally developed by Putnam et al., 1960, Management ond inventory of southern hardwoods, Agriculture Handbook 181, US For. Sew., Washington, DC, which consists of four tree classes: (1) preferred growing stock, (2) reserve growing...

  20. Exploring research priorities for the North American hardwood industry

    Science.gov (United States)

    David Brinberg; Earl Kline; Delton Alderman; Philip Araman; Ed Cesa; Steve Milauskas; Tom Walthousen; Jan Wiedenbeck

    2008-01-01

    With the increase of globalization, the North American hardwood industry is facing many challenges to remain competitive and sustainable, facing drastic changes in the areas of labor, land, manufacturing, markets and marketing, and supply chain. The hardwood industry is especially vulnerable, with the influx of foreign manufacturers and suppliers with greater natural...

  1. Southern hardwood forestry group going strong after 50 years

    Science.gov (United States)

    Brian Roy Lockhart; Steve Meadows; Jeff Portwood

    2005-01-01

    On November 15,200 1, the Southern Hardwood Forestry Group (referred to as the Group) met at the U.S. Forest Service Southern Research Station's Southern Hardwoods Laboratory in Stoneville, hlississippi to celebrate the Group's 50th anniversary. About 130 members and guests attended to celebrate the 50th anniversary of the Group and to honor its charter...

  2. Nondestructive evaluation of incipient decay in hardwood logs

    Science.gov (United States)

    Xiping Wang; Jan Wiedenbeck; Robert J. Ross; John W. Forsman; John R. Erickson; Crystal Pilon; Brian K. Brashaw

    2005-01-01

    Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide...

  3. Hardwood genetics and tree improvement - A Midwest USA perspective

    Science.gov (United States)

    C. H. Michler; R. Meilan; K. E. Woeste; P. M. Pijut; D. Jacobs; P. Aldrich; J. Glaubitz

    2005-01-01

    Fine hardwood trees in the Central Hardwoods region of the United States are an important resource for the furniture, cabinetry, flooring, modular home, and paneling manufacturing industries. Consumers find wood from these trees to be very desirable because of quality factors such as grain, strength and color. To enhance wood production, tree improvement programs can...

  4. Market Definition For Hardwood Timber in the Southern Appalachians

    Science.gov (United States)

    Jeffrey P. Prestemon; John M. Pye; Karen Lee Abt; David N. Wear

    1999-01-01

    Direct estimation of aggregate hardwood supply is seriously complicated by the diversity of prices, species, and site conditions in hardwood stands. An alternative approach is to aggregate regional supply based on stumpage values of individual stands, arguably the real driver of harvest decisions. Complicating this approach is that species-specific prices are only...

  5. Leaf area and net photosynthesis during development of Prunus serotina seedlings

    Science.gov (United States)

    Stephen B. Horsley; Kurt W. Gottschalk

    1993-01-01

    We used the plastochron index to study the relationship between plant age, leaf age and development, and net photosynthesis of black cherry (Prtmus serotina Ehrh.) seedlings. Leaf area and net photosynthesis were measured on all leaves >=75 mm of plants ranging in age from 7 to 20 plastochrons. Effects of plant developmental stage...

  6. The effect of ectomycorrhizal fungi and bacteria on pine seedlings

    Directory of Open Access Journals (Sweden)

    Hanna Dahm

    2014-08-01

    Full Text Available The effect of ecomycorrhizal fungi (Hebelon crustuliniforme(Bull.: Fr. Quél. 5392 and Pisolithus tinctorius (Pers. Coker et Couch 5335 and bacteria (Bacillus polymyxa and Azospirillum brasilense. associated with mycorrhizas on the growth of pine seedligs was investigated. In addition the influence of bacteria on fungal biomass production and the relationship between ectomycorrhizal fungi and fungi pathogenic to root of pine seedlings were determined. In general, the shoot/root ratio was higher in plants inoculated with Hebeloma crustuliniforme and bacteria than in the control seedlings (grown only under sterile conditions. In non-sterile substrate the root/shoot ratio of the mycorrhizal seedlings was lower as compared to the control. Similar phenomenon was noted in plants inoculated with the mycorrhizal fungus Pisolithus tinetorius. The bacteria used as well as the time of introduction of these organisms into the cultures of mycorrhiza fungi affected the production of fungal biomass. Hebeloma crustuliniforme and Pisolithus tinctorius inhibited the growth of Rizoctonia solani and Fusarium oxysporum fungi pathogenic to pine seedlings.

  7. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    Science.gov (United States)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  8. A predictive coexpression network identifies novel genes controlling the seed-to-seedling phase transition in arabidopsis Thaliana

    NARCIS (Netherlands)

    Silva, Anderson Tadeu; Ribone, Pamela A.; Chan, Raquel L.; Ligterink, Wilco; Hilhorst, Henk W.M.

    2016-01-01

    The transition from a quiescent dry seed to an actively growing photoautotrophic seedling is a complex and crucial trait for plant propagation. This study provides a detailed description of global gene expression in seven successive developmental stages of seedling establishment in Arabidopsis

  9. Cavity size and copper root pruning affect production and establishment of container-grown longleaf pine seedlings

    Science.gov (United States)

    Marry Anne Sword Sayer; James D. Haywood; Shi-Jean Susana Sung

    2009-01-01

    With six container types, we tested the effects of cavity size (i.e., 60, 93, and 170 ml) and copper root pruning on the root system development of longleaf pine (Pinus palustris Mill.) seedlings grown in a greenhouse. We then evaluated root egress during a root growth potential test and assessed seedling morphology and root system development 1 year after planting in...

  10. Effects of container cavity size and copper coating on field performance of container-grown longleaf pine seedlings

    Science.gov (United States)

    Shi-Jean Susana Sung; James D. Haywood; Mary A. Sword-Sayer; Kristina F. Connor; D. Andrew Scott

    2010-01-01

    Longleaf pine (Pinus palustris Mill.) seedlings were grown for 27 weeks in 3 container cavity sizes [small (S), medium (M), and large (L)], and half the containers were coated with copper (Cu). In November 2004, we planted 144 seedlings from each of 6 container treatments in each of 4 replications in central LA. All plots were burned in February 2006...

  11. Big-leaf mahogany (Swietenia macrophylla) seedling survival and growth across a topographic gradient in southeast Pará, Brazil

    Science.gov (United States)

    James Grogana; Mark S. Ashtona; Galv& atilde; Jurandir oc

    2003-01-01

    Adult populations of big-leaf mahogany (Swietenia macrophylla) occur in aggregations along seasonal streams in transitional evergreen forests of southeast Pará, Brazil. To test whether variable seedling survival and growth across topography may underlie this observed distribution pattern, we planted nursery-grown seedlings in the...

  12. Seed treatments with essential oils protect radish seedlings against drought

    Directory of Open Access Journals (Sweden)

    Joshua D. Klein

    2017-10-01

    Full Text Available Establishment of seedlings of economic crops is often reduced if there is not a steady supply of water. Essential oils (EO from plants are increasingly used instead of synthetic chemicals to protect plant and animal products against biotic and abiotic stresses. We investigated priming radish seeds by soaking or by matriconditioning with synthetic or natural compounds as a means of inducing resistance to drought stress, thus maintaining crop yield. Priming radish seeds for two hours in solutions of essential oils (EO thymol and carvacrol derived from Origanum syriacum, with “oregano natural product” (ONP; a solution of the residue remaining after EO extraction, or with the gibberellin synthesis inhibitor trinexapac ethyl (TE, was much more effective in inducing drought resistance than was matriconditioning with the same compounds in sawdust for two days. The latter treatment induced considerable fungal and bacterial infection in treated seeds if the substrate-matrix was not heat-treated beforehand. The increase in specific leaf area in plants from treated seeds was mostly consistent with an increase in leaf water content. Seed treatments with EO, ONP, and especially TE led to a three-fold increase in radish seedling survival compared with water-treated controls, when 21 day-old seedlings were irrigated after 6 days of drought. Under drought conditions, seedlings from treated seeds had a 2–3-fold increase in relative water content increased 2–3-fold, while membrane permeability decreased 20–50-fold as a result of the treatments. However, the physical benefits of the treatments often did not correlate with treatment-induced increases in physiological parameters such as pigments (chlorophyll, carotenoid, anthocyanin, pigment ratios (chlorophyll a/b, carotenoid/chlorophyll, or antioxidant activity. Seed treatments with biostimulants can be as effective as treatments with synthetic compounds in inducing drought resistance in seedlings.

  13. Central Hardwoods ecosystem vulnerability assessment and synthesis: a report from the Central Hardwoods Climate Change Response Framework project

    Science.gov (United States)

    Leslie Brandt; Hong He; Louis Iverson; Frank R. Thompson; Patricia Butler; Stephen Handler; Maria Janowiak; P. Danielle Shannon; Chris Swanston; Matthew Albrecht; Richard Blume-Weaver; Paul Deizman; John DePuy; William D. Dijak; Gary Dinkel; Songlin Fei; D. Todd Jones-Farrand; Michael Leahy; Stephen Matthews; Paul Nelson; Brad Oberle; Judi Perez; Matthew Peters; Anantha Prasad; Jeffrey E. Schneiderman; John Shuey; Adam B. Smith; Charles Studyvin; John M. Tirpak; Jeffery W. Walk; Wen J. Wang; Laura Watts; Dale Weigel; Steve. Westin

    2014-01-01

    The forests in the Central Hardwoods Region will be affected directly and indirectly by a changing climate over the next 100 years. This assessment evaluates the vulnerability of terrestrial ecosystems in the Central Hardwoods Region of Illinois, Indiana, and Missouri to a range of future climates. Information on current forest conditions, observed climate trends,...

  14. Soil properties in 35 y old pine and hardwood plantations after conversion from mixed pine-hardwood forest

    Science.gov (United States)

    D. Andrew Scott; Michael G. Messina

    2009-01-01

    Past management practices have changed much of the native mixed pine-hardwood forests on upland alluvial terraces of the western Gulf Coastal Plain to either pine monocultures or hardwood (angiosperm) stands. Changes in dominant tree species can alter soil chemical, biological, and physical properties and processes, thereby changing soil attributes, and ultimately,...

  15. Meeting forest restoration challenges: Using the Target Plant Concept

    Science.gov (United States)

    Kas Dumroese; Thomas D. Landis; Jeremy Pinto; Diane L. Haase; Kim W. Wilkinson; Anthony S. Davis

    2016-01-01

    Meeting forest restoration challenges relies on successful establishment of plant materials (e.g., seeds, cuttings, rooted cuttings, or seedlings, etc.; hereafter simply "seedlings"). The Target Plant Concept (TPC) provides a flexible framework that nursery managers and their clients can use to improve the survival and growth of these seedlings. The...

  16. Composting of organically amended/treated hardwood and softwood sawdust

    International Nuclear Information System (INIS)

    Takyi-Lartey, Rita

    2015-07-01

    Sawdust is a major waste produced by the wood industry. Adding value to sawdust through composting is one of the surest means by which environmental pollution could be minimized. About 500 kg of softwood and hardwood sawdust were separately mixed with mucuna leaves and kitchen waste in the ratio of 3:1:1 on weight basis and heaped using effluent from abattoir to develop composts. Objectives of the study were to monitor changes in the physico-chemical properties, NH4"+ ‒ N, NO3"‒ ‒ N, C:N ratio, minerals N, K, P, microbial load and toxic elements in the composts during a 12 week period. Germination test was also done to evaluate the stability and maturity of the composts developed. Degradation of softwood sawdust compost (SSC) was better in the mesophilic phase while that of hardwood sawdust compost (HSC) occurred in the thermophilic phase. Thus, significantly higher amount of the organic material in SSC was decomposed during the period as compared to HSC. Also, greater percentage of the nitrogen in the initial material of SSC was converted into plant-available inorganic nitrogen (NH4"+ and NO3"‒) than was achieved in HSC. Hence, most of the mineral nitrogen in HSC that was converted was lost, probably in the thermophilic phase. On the contrary, the amount of organic nitrogen contained in the finished composts of both SSC and HSC were adequately good for application to the soil. Additionally, concentrations of pathogenic microorganisms in SSC and HSC products were within acceptable limits in terms of toxicity on growing plants. The softwood sawdust compost was relatively more stable as compared to HSC under the experimental conditions. Concentrations of heavy metals in both SSC and HSC were also within acceptable limits that would cause no toxicity to plants. Also, moisture contents in both SSC and HSC were within the good range (40 - 60%) required for a good compost. Thus both SSC and HSC produced were of good quality. Further research targeting specific

  17. Screening cotton genotypes for seedling drought tolerance

    Directory of Open Access Journals (Sweden)

    Penna Julio C. Viglioni

    1998-01-01

    Full Text Available The objectives of this study were to adapt a screening method previously used to assess seedling drought tolerance in cereals for use in cotton (Gossypium hirsutum L. and to identify tolerant accessions among a wide range of genotypes. Ninety genotypes were screened in seven growth chamber experiments. Fifteen-day-old seedlings were subjected to four 4-day drought cycles, and plant survival was evaluated after each cycle. Three cycles are probably the minimum required in cotton work. Significant differences (at the 0.05 level or lower among entries were obtained in four of the seven experiments. A "confirmation test" with entries previously evaluated as "tolerant" (high survival and "susceptible" (low survival was run. A number of entries duplicated their earlier performance, but others did not, which indicates the need to reevaluate selections. Germplasms considered tolerant included: `IAC-13-1', `IAC-RM4-SM5', `Minas Sertaneja', `Acala 1517E-1' and `4521'. In general, the technique is simple, though time-consuming, with practical value for screening a large number of genotypes. Results from the screening tests generally agreed with field information. The screening procedure is suitable to select tolerant accessions from among a large number of entries in germplasm collections as a preliminary step in breeding for drought tolerance. This research also demonstrated the need to characterize the internal lack of uniformity in growth chambers to allow for adequate designs of experiments.

  18. N2-fixation and seedling growth promotion of lodgepole pine by endophytic Paenibacillus polymyxa.

    Science.gov (United States)

    Anand, Richa; Grayston, Susan; Chanway, Christopher

    2013-08-01

    We inoculated lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) with Paenibacillus polymyxa P2b-2R, a diazotrophic bacterium previously isolated from internal stem tissue of a naturally regenerating pine seedling to evaluate biological nitrogen fixation and seedling growth promotion by this microorganism. Seedlings generated from pine seed inoculated with strain P2b-2R were grown for up to 13 months in a N-limited soil mix containing 0.7 mM available N labeled as Ca((15)NO3)2 to facilitate detection of N2-fixation. Strain P2b-2R developed a persistent endophytic population comprising 10(2)-10(6) cfu g(-1) plant tissue inside pine roots, stems, and needles during the experiment. At the end of the growth period, P2b-2R had reduced seedling mortality by 14 % and (15)N foliar N abundance 79 % and doubled foliar N concentration and seedling biomass compared to controls. Our results suggest that N2-fixation by P. polymyxa enhanced growth of pine seedlings and support the hypothesis that plant-associated diazotrophs capable of endophytic colonization can satisfy a significant proportion of the N required by tree seedlings growing under N-limited conditions.

  19. Towards plant wires

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self...

  20. Seedling vigor and genetic variability for rice seed, seedling emergence and seedling traits

    International Nuclear Information System (INIS)

    Ali, S.S.; Jafri, S.J.H.; Jamil, M.; Ijaz, M.

    1994-01-01

    Eleven local rice cultivars including Basmati 370 were evaluated for seedling vigor. Three groups of traits were evaluated viz; seed traits (Seed density, seed volume see weight, paddy length and grain length), seed emergence traits (emergence %, emergence index and emergence rate index), and seedling traits (fresh root length, dry root weight, emergence percentage, root length, dry root weight, seed weight and relative root weight were observed significant, respectively. Seed density, relative root weight, emergence rate index and root to shoot ratio were relatively more amenable to improvement. Relative expected genetic advance was the function of heritability and coefficient of phenotypic variability, latter being more important. (author)

  1. Effects of auxin and misting on the rooting of herbaceous and hardwood cuttings from the fig tree Efeitos de auxina e nebulização no enraizamento de estacas herbáceas e lenhosas de figueira

    Directory of Open Access Journals (Sweden)

    Cleiton Mateus Sousa

    2013-06-01

    Full Text Available Propagation of the fig tree predominately uses hardwood cuttings obtained from pruning stock plants. With a view to optimising fig tree propagation, the effects of auxin and misting on the rooting of herbaceous and hardwood cuttings from the fig tree were evaluated. An experiment was set up in a 2x2x2 factorial design, with two types of cuttings (softwood and hardwood, two levels of auxin (0 and 1000 mg L-1 indolbutyric acid and two environments (with and without misting. Thirty days after starting the experiment, rooting, root length, sprouting and losses were all evaluated. The interaction of the type of cutting and the auxin was significant for rooting, sprouting, root length and cutting loss. Misting did not affect the variables analysed. In the absence of auxin, there was no difference between the type of cutting for rooting, length of root and sprouting, while the application of auxin (1,000 mg L-1 produced a reduction in these variables. The production of fig tree seedlings can be made from either softwood or hardwood cuttings and does not require the use of auxin or misting.A propagação da figueira predomina com o uso de estacas lenhosas obtidas após a poda de plantas matrizes. Visando otimizar a propagação da figueira, avaliou-se os efeitos da auxina e da nebulização no enraizamento de estacas herbáceas e lenhosas de figueira. Foi implantado um experimento em fatorial 2x2x2, sendo dois tipos de estacas (herbáceas e lenhosas, dois níveis de auxina (0 e 1.000 mg L-1 de ácido indolbultírico e dois ambientes (com ou sem nebulização. Aos 30 dias após a implantação do experimento, avaliou-se o enraizamento, comprimento da radícula, brotação e perdas. A interação do tipo de estaca e auxina foi significativa para enraizamento, brotação, comprimento da radícula e perdas de estacas. A nebulização não interferiu nas variáveis analisadas. Na ausência de auxina não houve diferença entre os tipos de estacas para o

  2. Pre-damage biomass allocation and not invasiveness predicts tolerance to damage in seedlings of woody species in Hawaii.

    Science.gov (United States)

    Lurie, Matthew H; Barton, Kasey E; Daehler, Curtis C

    2017-12-01

    Plant-herbivore interactions have been predicted to play a fundamental role in plant invasions, although support for this assertion from previous research is mixed. While plants may escape from specialist herbivores in their introduced ranges, herbivory from generalists is common. Tolerance traits may allow non-native plants to mitigate the negative consequences of generalist herbivory that they cannot avoid in their introduced range. Here we address whether tolerance to herbivory, quantified as survival and compensatory growth, is associated with plant invasion success in Hawaii and investigate traits that may enhance tolerance in seedlings, the life stage most susceptible to herbivory. In a greenhouse experiment, we measured seedling tolerance to simulated herbivory through mechanical damage (50% leaf removal) of 16 non-native woody plant species differing in invasion status (invasive vs. non-invasive). Seedlings were grown for 2 weeks following damage and analyzed for biomass to determine whether damaged plants could fully compensate for the lost leaf tissue. Over 99% of all seedlings survived defoliation. Although species varied significantly in their levels of compensation, there was no consistent difference between invasive and non-invasive species. Seedlings of 11 species undercompensated and remained substantially smaller than control seedlings 2 weeks after damage; four species were close to compensating, while one species overcompensated. Across species, compensation was positively associated with an increased investment in potential storage reserves, specifically cotyledons and roots, suggesting that these organs provide resources that help seedlings re-grow following damage. Our results add to a growing consensus that pre-damage growth patterns determine tolerance to damage, even in young seedlings which have relatively low biomass. The lack of higher tolerance in highly invasive species may suggest that invaders overcome herbivory barriers to invasion

  3. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  4. Linking carbon and water relations to drought-induced mortality in Pinus flexilis seedlings.

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J; Kueppers, Lara M; Domec, Jean-Christophe; Mitton, Jeffry

    2015-07-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below -5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations. © The Author 2015. Published by Oxford University Press. All rights reserved

  5. The influence of seedling density in containers on morphological characteristics of European beech

    Directory of Open Access Journals (Sweden)

    Wrzesiński Piotr

    2015-09-01

    Full Text Available This study examines the influence on growth parameters, in particular the morphological features of the root system, of 1-year-old European beech seedlings cultivated in containers with two different densities. The experiment was conducted in the container nursery in Skierdy (Forest District of Jabłonna in spring 2011. After 10 months of cultivation in Hiko polyethylene containers, above- and below-ground parts of the seedlings were measured. The measurements of the root system were conducted with a scanner and the WinRHIZO software. No influence due to the seedling density on either shoot height or thickness was observed, but instead the research showed that different seedling densities affected the development of root systems. The mean root thickness and dry mass of the European beech seedlings were significantly higher at the lower density. The influence of seedling density on the development of root mass deserves special attention as it is the most important factor affecting future growth of the seedlings during cultivation. This tendency also suggests that the amount of nutrients allocated to shoot development may be higher in order to improve the efficiency of photosynthesis. At both densities, differences in biomass accumulation affected the root-toshoot ratio. In seedlings cultivated at the lower density, the increased dry root matter of the seedlings resulted in a significant increase in the root-to-shoot ratio. This may cause a potential growth advantage of these seedlings after they are planted and may thus result in a more productive cultivation.

  6. Arabidopsis phosphoinositide-specific phospholipase C 4 negatively regulates seedling salt tolerance.

    Science.gov (United States)

    Xia, Keke; Wang, Bo; Zhang, Jiewei; Li, Yuan; Yang, Hailian; Ren, Dongtao

    2017-08-01

    Previous physiological and pharmacological studies have suggested that the activity of phosphoinositide-specific phospholipase C (PI-PLC) plays an important role in regulating plant salt stress responses by altering the intracellular Ca 2+ concentration. However, the individual members of plant PLCs involved in this process need to be identified. Here, the function of AtPLC4 in the salt stress response of Arabidopsis seedlings was analysed. plc4 mutant seedlings showed hyposensitivity to salt stress compared with Col-0 wild-type seedlings, and the salt hyposensitive phenotype could be complemented by the expression of native promoter-controlled AtPLC4. Transgenic seedlings with AtPLC4 overexpression (AtPLC4 OE) exhibited a salt-hypersensitive phenotype, while transgenic seedlings with its inactive mutant expression (AtPLC4m OE) did not exhibit this phenotype. Using aequorin as a Ca 2+ indicator in plc4 mutant and AtPLC4 OE seedlings, AtPLC4 was shown to positively regulate the salt-induced Ca 2+ increase. The salt-hypersensitive phenotype of AtPLC4 OE seedlings was partially rescued by EGTA. An analysis of salt-responsive genes revealed that the transcription of RD29B, MYB15 and ZAT10 was inversely regulated in plc4 mutant and AtPLC4 OE seedlings. Our findings suggest that AtPLC4 negatively regulates the salt tolerance of Arabidopsis seedlings, and Ca 2+ may be involved in regulating this process. © 2017 John Wiley & Sons Ltd.

  7. Seedling Regeneration in the Alpine Treeline Ecotone: Comparison of Wood Microsites and Adjacent Soil Substrates

    Directory of Open Access Journals (Sweden)

    Adelaide Chapman Johnson

    2016-11-01

    Full Text Available Although climate warming is generally expected to facilitate upward advance of forests, conifer seedling regeneration and survival may be hindered by low substrate moisture, high radiation, and both low and high snow accumulation. To better understand substrate-related factors promoting regeneration in the alpine treeline ecotone, this study compared 2 substrates supporting conifer seedlings: rotten downed wood and adjacent soil. Study locations, each with 3 levels of incoming radiation, were randomly selected at forest line–alpine meadow borders in Pacific Northwest wilderness areas extending along an east–west precipitation gradient. Associations among substrate type, seedling density, radiation, site moisture, site temperature, plant water potential, and plant stomatal conductance were assessed. Wood microsites, flush with the ground and supporting Abies spp conifer seedlings, extended up to 20 m into alpine meadows from the forest line. Although wood microsites thawed later in the spring and froze earlier in the fall, they had warmer summer temperatures, greater volumetric water content, and more growing degree hours, and seedlings growing on wood had higher water potentials than seedlings growing on adjacent soil. At drier eastern sites, there was a positive relationship between seedling density and volumetric water content. Further, there was a positive relationship between seedling stomatal conductance and volumetric water content. Our study indicates that in the Pacific Northwest. and likely elsewhere, seedlings benefit from wood microsites, which provide greater water content. Given predictions of increased summer drought in some locations globally, wood microsites at forest line–alpine meadows and forest line–grasslands borders may become increasingly important for successful conifer regeneration.

  8. [Effects of precipitation and interspecific competition on Quercus mongolica and pinus koraiensis seedlings growth].

    Science.gov (United States)

    Wu, Jing-Lian; Wang, Miao; Lin, Fei; Hao, Zhan-Qing; Ji, Lan-Zhu; Liu, Ya-Qin

    2009-02-01

    Aiming at the variation of precipitation pattern caused by global warming, a field simulation experiment was conducted to study the effects of 30% increase (+W) and decrease (-W) of precipitation on the morphology, growth, and biomass partitioning of mono- and mixed cultured seedlings of Quercus mongolica and Pinus koraiensis, the two dominant tree species in temperate broad-leaved Korean pine mixed forest in Changbai Mountains. Comparing with monoculture, mixed culture increased the canopy width and main root length of Q. mongolica seedlings, but decreased the basal diameter, plant height, leaf number, and dry masses of root, stem, leaf and whole plant of P. koraiensis seedlings significantly. Treatment (-W) increased the stem/mass ratio while decreased the main root length of Q. mongolica seedlings, and decreased the main root length, leaf number, dry masses of leaf and whole plant, and leaf/mass ratio, while increased the stem/mass ratio of P. koraiensis seedlings significantly, compared with treatment CK. Treatment (+W) had no significant effect on these indices of the two species. At early growth stage, interspecific competition and precipitation pattern had significant effects on the morphology and growth of the seedlings, and the responses were much stronger for P. koraiensis than for Q. mongolica.

  9. [Comparison of development condition of different Liriope spicata seedlings].

    Science.gov (United States)

    Wang, Yue; Su, He; Zhan, Yan-Ting; Yang, Yang; Dong, Xue-Hui

    2017-04-01

    The study identified the main morphological index of the seedlings classification including seedling age,the root width and number of newborn buds and coarse roots, according to the local agricultural production techniques and assessment of Liriope spicata's growth and development condition. After carrying on K cluster analysis of the morphological, we separated the seedlings into two levels. The first level (Ⅰ): the new talent with the root width exceeding two point five millimeters, the new born buds exceeding three, and with the coarse root exceeding one. The second level (Ⅱ): the old talent with the root width below one millimeters, the newborn buds below two and without coarse root. The study surveyed the plants' growth index dynamics, as well as the yield and quality of the tuberous root. The experimental results suggested that the growth condition of seedling Ⅰwas better, the yield of earthnut higher, the quality of earthnut more excellent. The study lied the foundation of L. spicata's grading standards and standardized production. Copyright© by the Chinese Pharmaceutical Association.

  10. Experiences in the containerized tree seedlings forest nurseries production

    Directory of Open Access Journals (Sweden)

    Eduardo González-Izquierdo

    2014-12-01

    Full Text Available The work summarizes the results of the research carried out by the team of forest nurseries at Sustainable Forest Management Group in Pinar del Río University Forest Research Centre in the last 25 years. The characteristics of seedlings quality are presented, the best growing media, the water management to harden the forest species under the ecological conditions of more and more lingering periods of drought. The studied forest species were: Talipariti elatum (Sw. Fryxell, Pinus tropicalis Morelet , Swietenia mahagon(L.Jacq. Swietenia macrophylla King, Caesalpinia violacea (Mill. Stand, Genipa americana L, Gerascanthus gerascanthoides (Kunth Borhidi y Cedrela odorata L. y Eucalyptus grandis Hill ex Maiden. The main results can be summarized in the following way: the size of the containers oscillates between 90 and 300 cubic centimeters; the growing media combines organic and composted components fundamentally of Pinus caribaea and Eucalyptus ssp bark., with proportions that they vary according to the species and the disposability of these components in the nurseries where the plants take place; for the water management hardening procedures were used by watering in last month of the cultivation. In general the economic analyses demonstrated the decrease of the production costs for seedlings with the employment of this novel technology, the same as their advantages on the traditional technology of seedlings production in polybags: humanization of manpower work in forest nursery, reduction of costs production, improvement of produced seedling quality and productivity increase of their workers.

  11. Measuring Maize Seedling Drought Response in Search of Tolerant Germplasm

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    Dirk Hays

    2013-02-01

    Full Text Available To identify and develop drought tolerant maize (Zea mays L., high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and their hybrid testcross progeny were evaluated for germination, survival and recovery after a series of drought cycles. Genotypic differences among inbred lines and hybrid testcrosses were best explained approximately 13 and 18 days after planting, respectively. Genotypic effects were significant and explained over 6% of experimental variance. Specifically three inbred lines had significant survival, and 14 hybrids had significant recovery. However, no significant correlation was observed between hybrids and inbreds (R2 = 0.03, indicating seedling stress response is more useful as a secondary screening parameter in hybrids than in inbred lines per se. Field yield data under full and limited irrigation indicated that seedling drought mechanisms were independent of drought responses at flowering in this study.

  12. Regulation of Flavonoid Biosynthetic Genes in Germinating Arabidopsis Seedlings.

    Science.gov (United States)

    Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM

    1992-01-01

    Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632

  13. Salt tolerance of physalis during germination and seedling growth

    International Nuclear Information System (INIS)

    Yildirim, E.; Karlidag, H.

    2011-01-01

    The study was conducted to evaluate the effect of NaCl salinity on germination and emergence of Physalis ixocarpa and Physalis peruviana. Seeds of P. ixocarpa and P. peruviana were germinated by the use of 0, 30, 60, 90, 120 and 180 mM NaCl solutions in petri dishes. Final germination percentage (FGP) decreased with the increase in NaCl concentration. Both species germinated at the ranges of salinity. P. peruviana gave the greater germination percentages under salt stress than P. ixocarpa. NaCl salinity at different concentrations adversely affected germination rates. For seedling growth, seeds of both species were sown at 10 mm depth in plastic trays filled with peat to determine final emergence percentage (FEP). The trays were irrigated manually to saturation every day with 0, 30, 60, 90, 120, 150 or 180 mM NaCl solutions to maintain the level of salinity. Salinity affected seed emergence and seedlings growth more than seed germination. The study showed that no emergence of Physalis was observed at 90, 120 and 180 mM NaCl salinity. Fresh and dry weights of normal seedlings were also evaluated. Salt stress significantly decreased the plant fresh and dry weight of both species. Based on the results of the experiment, it can be concluded that seedling emergence and growth is more sensitive to salt stress than seed germination in Physalis. (author)

  14. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    Science.gov (United States)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  15. Spatial distribution of seeds and seedlings of two tropical tree species: Is there correspondence between patterns?

    International Nuclear Information System (INIS)

    Parrado Rosselli, Angela

    2007-01-01

    The spatial patterns of seed and seedling distribution relative to parent trees (seed and seedling shadow, respectively) were studied for Dacryodes chimantensis (Burseraceae) and Brosimum utile (Moraceae), two common tree species of terra firme forests of Colombian Amazonia. The general objective was to assess whether the patterns imposed by seed dispersal change or persist in subsequent life stages occurring during the transition from seeds/saplings to adult stages. Seed and seedling shadows on the ground were characterized for each tree species along four 50-m radial transects from the base of the parent tree. Causes of seed and seedling predation as a function of distance to the parent tree were determined, as well as the spatial consistency between life stages. Results showed that seed density of both Dacryodes and Brosimum declined leptokurtically with distance, and it was skewed towards the parent tree. However, seed density was more skewed and leptokurtic in Dacryodes than in Brosimum. The overall trend was maintained in the seedling stage of both species and was positively correlated with the distribution patterns of seeds. Seed and seedling predation were positively correlated with density and negatively correlated with the distance from the parent tree. Factors that could be generating the high consistency between the spatial patterns of seed and seedling distribution are discussed, as well as its implications in the population structure of both species and the debate on the factors that influence the spatial distribution of plant species in tropical rain forests.

  16. Use of aquatic macrophytes in substrate composition to produce moringa seedlings

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2016-03-01

    Full Text Available The use of aquatic macrophytes in substrate composition to produce seedlings of moringa is a sustainable alternative. Therefore, the objective of this research was to evaluate the development of moringa seedlings using substrates composed with aquatic macrophytes, and to determine concentrations of N, P and K in the seedlings. We used different combinations of weeds (M, manure (E and topsoil (TV to compose the substrates. The experiment was conducted in a 3 × 4 factorial in randomized arrangement with four replications. We evaluated plant height, crown diameter and stem, relative growth rate in height, canopy diameter and in stem, dry matter of aerial part and of roots, root length and root/shoot ratio, besides the content of N, P and K in seedlings. Moringa seedlings showed reduced growth when produced in substrates composed only with cattail. Water lettuce and substrates composed of 60% M + 30%E + 10 % TV and 70% M + 30% E, promoted greater nutrition and growth of moringa seedlings. The substrate 60M +30E +10TV composed by water hyacinth and cattail resulted in greater amount of P in moringa seedlings.

  17. GROWTH OF Jacaranda puberula Cham. SEEDLINGS IN NURSERY UNDER DIFFERENT SHADING LEVELS

    Directory of Open Access Journals (Sweden)

    Lausanne Soraya de Almeida

    2010-08-01

    Full Text Available Jacaranda puberula, known as caroba, is a species that presents potential use for the recovery of degraded areas, since it possesses fast growth and adapts well to sandy and loamy soils. It presents great aggressiveness in secondary forests and it can be used as urban tree because it produces beautiful lilac flowers. With the intention of obtaining information about potential species for use in recovery of riparian forest, were tested in the nursery of the city hall of the municipal district of Colombo, the development of seedlings of Jacaranda puberula submitted at 30, 50 and 70% of shading. There were used 40 seedlings by treatment and there were evaluated the following parameters: height (60, 90 and 120 days and diameter (90 and 120 days of all seedlings, leaf area and root and shoot dry weight of 6 seedlings per treatment. The largest averages of the analyzed variables were obtained for the 30% shading, except for root dry weight.  The seedlings exposed to full sun presented high mortality rate and was not compared to the others. The smallest averages of the analyzed variables, except for height, were observed for the shading of 70%, indicating that this treatment is not advisable for the production of seedlings of this species in nursery. The best condition for planting the seedlings appears to be in open areas with shading of 30 to 50%, since its natural occurrence is not at full exposure.

  18. Seedling establishment in a masting desert shrub parallels the pattern for forest trees

    Science.gov (United States)

    Meyer, Susan E.; Pendleton, Burton K.

    2015-05-01

    The masting phenomenon along with its accompanying suite of seedling adaptive traits has been well studied in forest trees but has rarely been examined in desert shrubs. Blackbrush (Coleogyne ramosissima) is a regionally dominant North American desert shrub whose seeds are produced in mast events and scatter-hoarded by rodents. We followed the fate of seedlings in intact stands vs. small-scale disturbances at four contrasting sites for nine growing seasons following emergence after a mast year. The primary cause of first-year mortality was post-emergence cache excavation and seedling predation, with contrasting impacts at sites with different heteromyid rodent seed predators. Long-term establishment patterns were strongly affected by rodent activity in the weeks following emergence. Survivorship curves generally showed decreased mortality risk with age but differed among sites even after the first year. There were no detectable effects of inter-annual precipitation variability or site climatic differences on survival. Intraspecific competition from conspecific adults had strong impacts on survival and growth, both of which were higher on small-scale disturbances, but similar in openings and under shrub crowns in intact stands. This suggests that adult plants preempted soil resources in the interspaces. Aside from effects on seedling predation, there was little evidence for facilitation or interference beneath adult plant crowns. Plants in intact stands were still small and clearly juvenile after nine years, showing that blackbrush forms cohorts of suppressed plants similar to the seedling banks of closed forests. Seedling banks function in the absence of a persistent seed bank in replacement after adult plant death (gap formation), which is temporally uncoupled from masting and associated recruitment events. This study demonstrates that the seedling establishment syndrome associated with masting has evolved in desert shrublands as well as in forests.

  19. Effect of canopy position on germination and seedling survival of epiphytic bromeliads in a Mexican humid montane forest.

    Science.gov (United States)

    Winkler, Manuela; Hülber, Karl; Hietz, Peter

    2005-05-01

    Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses. The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2.5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations. Experimental germination percentages ranged from 7.2 % in Tillandsia deppeana to 33.7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3.5 and 9.4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season. Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage.

  20. RESEARCH ON THE DEVELOPMENT OF ALTERNATIVE TECHNOLOGIES FOR THE PRODUCTION OF TOMATO SEEDLINGS IN DRĂGANU ARGEŞ

    Directory of Open Access Journals (Sweden)

    Florina Uleanu

    2017-12-01

    Full Text Available This paper aims to find the most efficient techniques for the production of seedlings because it represents one of the greatest concerns of the vegetable growers, being a subject of great interest. A special attention shows determining influence of different pots, plastic or biodegradable, on the growth and development of tomato seedlings. The replanting of the seedlings was carried out in various pots (of polyethylene film, from peat, Jiffy pots, small and big alveolar pallets filled with nutritional mixture. The best growth in height was achieved in seedlings transplanted in polyethylene pots (B1, except for Parris hybrid, the favorable effects on seedlings growth being explained by their better nutritional capacity as a result of the development of a stronger root system. As a type of pot, it is noted that seedlings transplanted into large alveolar pallets formed floral buds before planting in all hybrids studied. The type of pots used to transplant seedlings, and especially their size, positively influences the number of leaves. This work brings to the forefront the influence of different pots of plastic or biodegradable material on the growth and development of tomato seedlings that have been transplanted and maintained in these pots until planting.

  1. Physiological and foliar injury responses of Prunus serotina, Fraxinus americana, and Acer rubrum seedlings to varying soil moisture and ozone

    International Nuclear Information System (INIS)

    Schaub, M.; Skelly, J.M.; Steiner, K.C.; Davis, D.D.; Pennypacker, S.P.; Zhang, J.; Ferdinand, J.A.; Savage, J.E.; Stevenson, R.E.

    2003-01-01

    High soil water availability favors ozone uptake, increases foliar injury, and exacerbates the negative ozone effect on gas exchange of seedlings of deciduous tree species. - Sixteen black cherry (Prunus serotina, Ehrh.), 10 white ash (Fraxinus americana, L.) and 10 red maple (Acer rubrum, L.) 1-year old seedlings were planted per plot in 1997 on a former nursery bed within 12 open-top chambers and six open plots. Seedlings were exposed to three different ozone scenarios (ambient air: 100% O 3 ; non-filtered air: 98% ambient O 3 ; charcoal-filtered air: 50% ambient O 3 ) within each of two different water regimes (nine plots irrigated, nine plots non-irrigated) during three growing seasons. During the 1998 and 1999 growing season, leaf gas exchange, plant water relations, and foliar injury were measured. Climatic data, ambient- and chamber-ozone-concentrations were monitored. We found that seedlings grown under irrigated conditions had similar (in 1998) but significantly higher gas exchange rates (in 1999) than seedlings grown within non-irrigated plots among similar ozone exposures. Cherry and ash had similar ozone uptake but cherry developed more ozone-induced injury (<34% affected leaf area, LAA) than ash (<5% LAA), while maple rarely showed foliar injury, indicating the species differed in ozone sensitivity. Significantly more severe injury on seedlings grown under irrigated conditions than seedlings grown under non-irrigated conditions demonstrated that soil moisture altered seedling responses to ambient ozone exposures

  2. Vegetative Propagation and the Genetic Improvement of North American Hardwoods

    Science.gov (United States)

    R. E. Farmer

    1973-01-01

    Progress and problems in vegetative propagation of important North American hardwoods are reviewed with emphasis on rooting cuttings and the application of propagation techniques in breeding research. Some problems in rooting physiology are discussed.

  3. How second-growth northern hardwoods develop after thinning

    Science.gov (United States)

    Robert W., Jr. Wilson

    1953-01-01

    In the northern hardwood region, second-growth stands occupy thousands of acres. These stands are of all ages, in all conditions. They were brought about by fire, charcoal and fuelwood cuttings, land abandonment, or a combination of these causes.

  4. Two eras of globalization and hardwood sawtimber demand

    Science.gov (United States)

    William G. Luppold; Matthew S. Bumgardner

    2006-01-01

    In the early 1970s, the adoption of floating exchange rates resulted in more fluid transfers between international currencies and spurred increased international demand for hardwood lumber produced in the United States.

  5. Endophytic bacteria in cacti seeds can improve the development of cactus seedlings.

    Science.gov (United States)

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association between the giant cardon cactus Pachycereus pringlei and endophytic bacteria help seedlings establish and grow on barren rock, This cactus, together with other desert plants, is responsible for weathering ancient lava flows in the Baja California Peninsula of Mexico.When cardon seeds are inoculated with endophytic...

  6. Establishing Longleaf Pine Seedlings Under a Loblolly Pine Canopy (User’s Guide)

    Science.gov (United States)

    2017-02-01

    longleaf pine forests (Figure 1) for the diverse values they provide. These forests afford abundant recreational opportunities like hiking , bird...combined herbicide-fertilizer treatments that might benefit planted longleaf pine seedlings after planting. In addition to measuring longleaf pine

  7. Effects of genetics, management intensity, and seedling density on early stocking in loblolly pine

    Science.gov (United States)

    Scott D. Roberts; Randall J. Rousseau; B. Landis Herrin

    2015-01-01

    Rapid establishment and early tree growth can be key factors in successful plantation management. This generally entails planting good quality planting stock at a seedling density appropriate for the management objectives and then managing at an appropriate intensity with a goal of fully occupying the site as quickly as possible within the context of those objectives....

  8. Evaluation of RPM™ oak seedlings in afforesting floodplain crop fields along the Missouri River

    Science.gov (United States)

    Daniel C. Dey; John M. Kabrick; Michael A. Gold

    2005-01-01

    Regenerating oaks in agricultural floodplains is problematic because of their slow juvenile shoot growth, intense plant competition, seasonal flooding, and browsing by wildlife. Planting large nursery stock has been recommended to increase the competitiveness of oak seedlings. The Forrest Keeling Nursery in Missouri developed the Root Production Method (RPM™)...

  9. Antibiotics Do Not Control Blister Rust in Eastern White Pine Seedlings

    Science.gov (United States)

    William R. Phelps; Ray Weber

    1968-01-01

    To prevent blister rust infections in Eastern white pine seedlings, the antibiotics, cycloheximide (acti-dione) and Phytoactin, were tested in root dips, root slurries, and foliar drenches before planting and after planting the trees. None of the methods and materials tested was effective.

  10. SALINITY TOLERANCE OF SEVERAL RICE GENOTYPES AT SEEDLING STAGE

    Directory of Open Access Journals (Sweden)

    Heni Safitri

    2018-01-01

    Full Text Available Salinity is one of the most serious problems in rice cultivation. Salinity drastically reduced plant growth and yield, especially at seedling stage. Several rice genotypes have been produced, but their tolerance to salinity has not yet been evaluated. The study aimed to evaluate salinity tolerance of rice genotypes at seedling stage. The glasshouse experiment was conducted at Cimanggu Experimental Station, Bogor, from April to May 2013. Thirteen rice genotypes and two check varieties, namely Pokkali (salt tolerant and IR29 (salt sensitive were tested at seedling stage. The experiment was arranged in a randomized complete block design with three replications and two factors, namely the levels of NaCl (0 and 120 mM and 13 genotypes of rice. Rice seedlings were grown in the nutrient culture (hydroponic supplemented with NaCl at different levels. The growth and salinity injury levels of the genotypes were recorded periodically. The results showed that salinity level of 120 mM NaCl reduced seedling growth of all rice genotypes, but the tolerant ones were survived after 14 days or until the sensitive check variety died. Based on the visual injury symptoms on the leaves, five genotypes, i.e. Dendang, Inpara 5, Inpari 29, IR77674-3B-8-2-2-14-4-AJY2, and IR81493-BBB-6-B- 2-1-2 were tolerant to 120 mM salinity level, while Inpara 4 was comparable to salt sensitive IR29. Hence, Inpara 4 could be used as a salinity sensitive genotype for future research of testing tolerant variety. Further evaluation is needed to confirm their salinity tolerance under field conditions. 

  11. Morphological and photosynthetic adaptations of Tabebuia aurea seedlings in the nursery

    Directory of Open Access Journals (Sweden)

    Eduardo R Gonçalves

    2013-11-01

    Full Text Available Tabebuia aurea (Benth. & Hook. f. ex S. Moore (Bignoniaceae is a boreal species common in Brazil. It is used for ornamental parks and along sidewalks. Its timber is also used for furniture. The objective of this study was to evaluate the effect of nursery shading on the growth and photosynthesis of T. aurea and their photosynthetic adaptation after being transferred to direct sunlight. The T. aurea seedlings were grown under 0, 50, 70 or 95% shade. The photosynthetic active radiation and leaf gas exchange were measured over two distinct periods: 51 (young seedlings and 70 days after having been sown under each shade treatment. Immediately after the measurements were taken, the seedlings were transferred into full sunlight and the measurements were repeated two times after 15 min and 3 days under ambient sunlight. T. aurea seedlings showed satisfactory growth up to 50% shade in the nursery, which could be verified both by growth measurement and by total biomass accumulation. Shading greater than 70% reduced the number of leaves, the leaf area and the stem diameter in relation to plants exposed to full sunlight. The results suggest that T. aurea seedlings should be grown under full sunlight or under shading up to 50% to maximize their growth in the nursery and to minimize stress when transferring the seedlings to their final planting sites.

  12. Reforestation of bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    N. Krishnakumar

    2012-11-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted indegradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth.However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum(Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum(Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings of Eucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings of E. tereticornis showed 95% survival over the control seedlings and their growth was also significantlyhigher. Tissue nutrients (N, P, K were also found higher inAM fungi inoculated E. tereticornis than un inoculated control seedlings.

  13. Reforestation of Bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with Arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    A. Karthikeyan

    2012-12-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted in degradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth. However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum (Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum (Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings ofEucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings ofE. tereticornis showed 95% survival over the control seedlings and their growth was also significantly higher. Tissue nutrients (N, P, K were also found higher in AM fungi inoculated E. tereticornis than un inoculated control seedlings

  14. Seedling emergence of an array of Campomanesia adamantium (Cambess. O. Berg, under different conditions

    Directory of Open Access Journals (Sweden)

    Kaila Ressel

    2014-12-01

    Full Text Available Seedling emergence of an array of Campomanesia adamantium (Cambess. O. Berg, under different conditions. Campomanesia adamantium are shrubs with berries that are yellow when ripe, with sweet, aromatic and juicy pulp. The fruits are very appreciated by the Midwestern Brazilian population because, beyond the economic potential, gabirobeiras have important ecological and medicinal applications. The few reports concerning methods of C. adamantium propagation demonstrate varied responses of the germination process, and variation sometimes occurs for seeds planted under similar conditions. The objective of this study was to evaluate the inluence of different substrates and seed pulp extraction methods on seedling emergence of C. adamantium. Seeds were collected from a single individual. The experiment tested four methods of seed pulp extraction: a Control: seeds sown with pulp, b seeds whose pulp was mechanically removed by friction using fine sawdust, c seeds whose pulp was removed by washing in running water; d seeds with pulp soaked for 24 h. Four different substrates per pulp extraction type were then used for planting: 1 Vermiculite; 2 Plantmax ®; 3 Tri-Mix ®, 4 washed medium-grain sand. Sand was the substrate that produced the best result for seedling emergence, however there were no significant differences in seedling emergence between seed processing methods. The presence of seed pulp did not impact percent seedling emergence, nor did it affect average time or speed of seedling emergence.

  15. SEED, SEEDLINGS AND GERMINATION MORPHOLOGY OF Copaifera langsdorfii Desf. (Leguminosae-Caesalpinioideae

    Directory of Open Access Journals (Sweden)

    Maria Elane de Carvalho Guerra

    2006-12-01

    Full Text Available The knowledge of seed and seedling morphology are extremely important to the identification and preservation of plant species. In order to studying seed and seedling morphology and seed germination of copaiba (Copaifera langsdorfii Desf seeds, experiments were conducted at the Laboratory of Seed Analysis and Laboratory of Botany of the Federal University of Ceará. In copaíba seeds the characteristics studied were shape, size (length, width, thickness and morphology. The kind of germination, the root systems, hypocotyls, epicotyls and first leaves were the characteristics evaluated in copaiba seedlings. Ruler and pachimeter were used to make the measurements, as well as optical microscope and magnifying glass. The seeds are exalbumin kind, have neuter photoblastism and epigeous germination. Seed coat shows a palisade cell layer with a conspicuous light line. The seedlings have compound first leaves and axial root system.

  16. The role of vanillin and p-coumaric acid in the growth of Scotch pine seedlings

    Directory of Open Access Journals (Sweden)

    M. Michniewicz

    2015-01-01

    Full Text Available It was stated that vanillin and p-coumaric acid used at concentrations 10-8-10-5M stimulated the growth of pine seedlings. Most effective were these substances used at concentration 10-7M. Both phenolic compounds stimulated the elongation, fresh and dry weight in very young seedlings (up to 3-4 weeks and increased the fresh and dry weight only in older ones (7 weeks. The stimulation of growth processes in pine seedlings treated with vanillin and p-coumaric acid coincided with the increase of auxins in roots and with the decrease of free gibberellins in these plant organs. Neither vanillin nor p-coumaric acid influenced the level of ABA-like inhibitor both in the shoots and roots of pine seedlings.

  17. The effects of ultraviolet radiation on the growth and gross morphology of Zea mays, Linn. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ann Kristine Joy T.; Mendiola, Carlo Paulo T

    2000-03-01

    The study was conducted with a descriptive experimental design in order to determine the effects of broad spectrum ultraviolet radiation on growth factors, seedling height, root length, chlorophyll content, organic weights, and percentage survival, as well as gross morphological factors, leaf, stem, and root appearance, of native sweet corn seedlings. The study was limited to the seedling stage of the plant and observations were taken after 20 days of treatment. The results gathered show that there was a visible manifestation of the detrimental effects of UV on the irradiated seedlings. There were observed decreases in the growth parameters while the gross morphological parameters exhibited signs of wilting and stress. It was therefore concluded that based on the observed results, UV had a detrimental effect on the studied growth and gross morphological parameters. (Author)

  18. Evaluation of substrates for seedlings establishment in laboratory of Puya raimondii Harms (Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Giovana Vadillo

    2006-10-01

    Full Text Available Puya raimondii Harms (Bromeliaceae is a monocarpic plant, that can produce about 6 to 12 million seeds, nevertheless is very rare to find seedlings in their natural habitat, indicating difficulties for its establishment. In this work, the conditions for establishment of P. raimondii under laboratory conditions were determined carrying out experiments to determine the better substrate. It was compared the survival and vigour of P. raimondii seedling that were transplanted in peat, moss, peat-soil and moss-soil substrates. The peat substrate showed high survival and was better for establishment of seedlings because it maintains steady and suitable humidity and pH conditions, this allowed that seedlings presents a good vigour. Substrates with very little (case peat-earth or too much (case moss humidity retention had a negative effect over vigour and development.

  19. Identification of 'Ubá' mango tree zygotic and nucellar seedlings using ISSR markers

    Directory of Open Access Journals (Sweden)

    Aline Rocha

    2014-10-01

    Full Text Available Polyembryonic seeds are characterized by the development of over one embryo in the same seed, which can be zygotic and nucellar. The objective of this work was to identify the genetic origin, whether zygotic or nucellar, of seedlings of polyembryonic seeds of 'Ubá' mango tree using ISSR markers, and relating them with the vigor of the seedlings. Thus, mangos were harvested in Visconde do Rio Branco (accession 102 and Ubá (accessions 112, 138, 152 and 159, whose seeds were germinated in plastic trays filled with washed sand. Fifty days after sowing, seedlings from five seeds of each one of the accessions 102, 112, 138, 159 and from 10 seeds of the accession 152, were analyzed. These sseedlings were characterized and evaluated for plant height, stem circumference and mass of fresh aerial part and the most vigorous seedling was the one displaying at least two of these traits higher than the other seedlings from seed. Leaves were collected for genomic DNA extraction, which was amplified using seven ISSR primers previously selected based on the amplification profile and considering the number and resolution of fragments. Zygotic seedlings were found in 18 seeds, which were the most vigorous in six seeds. The results evidenced the existence of genetic variability in orchards using seedlings grown from seeds, because the farmer usually uses the most vigorous ones, assuming that this is of nucellar origin. These results also indicate that the most vigorous seedling are not always nucellar, inasmuch as of 20% of the total seeds evaluated, the zygotic seedling was the most vigorous.

  20. [Effects of different endophytic fungi on seedling growth of Dendrobium devonianum].

    Science.gov (United States)

    Huang, Hui; Shao, Shi-Cheng; Gao, Jiang-Yun

    2016-06-01

    To obtain seedling growth-promoting fungi is a key step in restoration-friendly cultivation of medicinal Dendrobium species, since there are a large number of functionally-unknown endophytic fungi in the roots of Dendrobium plants.In this study, six functionally-unknown endophytic fungal strains were isolated from roots of D.devonianum using single peleton isolation technology, and used in inoculation experiments to test their effectiveness for seedling growth in D.devonianum.After 90 days of inoculation, comparing with the control treatment, FDdS-1, FDdS-2 and FDdS-4 showed strong pathogenic or fatal effects on seedlings; while, FDdS-12, FDdS-9 and FDdS-5 had different effects on seedling growth.FDdS-5 had significant promoting effects on height, fresh and dry weight, stem diameter and root numbers, while FDdS-9 only had significant promoting effect on seedling height, and FDdS-12 had a negative effect on seedling growth.According to the anatomical features of the inoculated roots, FDdS-5 fungi could infect the velamina of seedlings and the existence of symbiosis pelotons in the cortex cells, suggesting that FDdS-5 is a mycorrhiza fungi of D.devonianum.FDdS-5 and FDdS-9 were identified as Sebacina vermifera and Sebacina sp.by molecular technologies.By using FDdS-5 in the restoration-friendly cultivation of D.devonianum, it could effectively promote seedling growth and shorten the seedling growth periods.The results will aid in reintroduction and cultivation of D.devonianum. Copyright© by the Chinese Pharmaceutical Association.

  1. Influence of establishment timing and planting stock on early rotational growth of loblolly pine plantations in Texas

    Science.gov (United States)

    M. A. Blazier; E. L. Taylor; A. G. Holley

    2010-01-01

    Planting container seedlings, which have relatively fully formed root systems encased in a soil-filled plug, may improve loblolly pine plantation productivity by increasing early survival and growth relative to that of conventionally planted bareroot seedlings. Planting seedlings in fall may also confer productivity increases to loblolly pine plantations by giving...

  2. Specificity of fungal associations of Pyroleae and Monotropa hypopitys during germination and seedling development.

    Science.gov (United States)

    Johansson, V A; Bahram, M; Tedersoo, L; Kõljalg, U; Eriksson, O

    2017-05-01

    Mycoheterotrophic plants obtain organic carbon from associated mycorrhizal fungi, fully or partially. Angiosperms with this form of nutrition possess exceptionally small 'dust seeds' which after germination develop 'seedlings' that remain subterranean for several years, fully dependent on fungi for supply of carbon. Mycoheterotrophs which as adults have photosynthesis thus develop from full to partial mycoheterotrophy, or autotrophy, during ontogeny. Mycoheterotrophic plants may represent a gradient of variation in a parasitism-mutualism continuum, both among and within species. Previous studies on plant-fungal associations in mycoheterotrophs have focused on either germination or the adult life stages of the plant. Much less is known about the fungal associations during development of the subterranean seedlings. We investigated germination and seedling development and the diversity of fungi associated with germinating seeds and subterranean seedlings (juveniles) in five Monotropoideae (Ericaceae) species, the full mycoheterotroph Monotropa hypopitys and the putatively partial mycoheterotrophs Pyrola chlorantha, P. rotundifolia, Moneses uniflora and Chimaphila umbellata. Seedlings retrieved from seed sowing experiments in the field were used to examine diversity of fungal associates, using pyrosequencing analysis of ITS2 region for fungal identification. The investigated species varied with regard to germination, seedling development and diversity of associated fungi during juvenile ontogeny. Results suggest that fungal host specificity increases during juvenile ontogeny, most pronounced in the fully mycoheterotrophic species, but a narrowing of fungal associates was found also in two partially mycoheterotrophic species. We suggest that variation in specificity of associated fungi during seedling ontogeny in mycoheterotrophs represents ongoing evolution along a parasitism-mutualism continuum. © 2017 John Wiley & Sons Ltd.

  3. Growth, water relations and photosynthesis of seedlings and resprouts after fire

    Science.gov (United States)

    Clemente, Adelaide S.; Rego, Francisco C.; Correia, Otília A.

    2005-05-01

    Seasonal patterns of growth, water relations, photosynthesis and leaf characteristics were compared between obligate seeders ( Cistus monspeliensis and Cistus ladanifer) and resprouters ( Arbutus unedo and Pistacia lentiscus) from the first to the second year after fire. We hypothesized that seedlings would be more water-limited than resprouts due to their shallower root systems. Regarding water use strategies, Cistus species are drought semi-deciduous and A. unedo and P. lentiscus are evergreen sclerophylls, therefore, comparisons were based on the relative deviation from mature conspecific plants. Seedlings and resprouts had higher shoot elongation and leaf production than mature plants, and over an extended period. Differences from mature plants were larger in resprouts, with two-fold transpiration, leaf conductance and photosynthesis in late spring/early summer. Seedlings of C. monspeliensis exhibited higher transpiration and leaf conductance than mature plants, while those of C. ladanifer only exhibited higher water potential. Growth increments and ameliorated water relations and photosynthesis after fire were attributed to an increase in water and nutrient availability. The small differences in water relations and photosynthesis between seedlings and mature conspecifics are in accordance with the prediction of seedlings experiencing higher water limitation than resprouts. We attribute these results to differences in root systems: resprouters benefited from an increase in root/shoot ratios and the presence of deep roots whereas Cistus seedlings relied on very shallow roots, which cannot provide assess to deep water during summer. Nevertheless, seedlings did not show evidence of experiencing a more severe water limitation than mature conspecifics, which we attributed to the presence of efficient mechanisms of avoiding and tolerating water stress. The results are discussed in relation to post-fire demography of seeders and resprouters in Mediterranean

  4. Asymbiotic germination, seedling development and plantlet propagation of Encyclia aff. oncidioides - an endangered orchid

    Directory of Open Access Journals (Sweden)

    Ewa Łojkowska

    2011-01-01

    Full Text Available In order to estimate the best germination conditions of Encyclia aff. oncidioides seeds, five different media (Fast, Knudson C modified by Vajrabhaya, Murashige and Skoog, PB2 and modified Vacin and Went with different concentrations of plant growth regulators such as benzyladenine (BA, naphthaleneacetic acid (NAA and gibberellic acid (GA3 were tested. No beneficial effect was observed when BA and NAA were applied to the germination medium and GA3 inhibited germination. The effect of light, activated charcoal, coconut water and casein hydrolysate on seed germination was also studied. The growth rate of seedlings on three different media supplemented with activated charcoal and plant growth regulators was checked. The applied plant growth regulators had no beneficial effect on the further growth of seedlings. Fast and PB2 media with 0.2% activated charcoal proved to be the best for E. aff. oncidioides seed germination, seedling development and plantlet propagation.

  5. Why Seedlings Die: Linking Carbon and Water Limitations to Mechanisms of Mortality During Establishment in Conifer Seedlings

    Science.gov (United States)

    Reinhardt, K.; Germino, M. J.; Kueppers, L. M.; Mitton, J.; Castanha, C.

    2012-12-01

    BACKGROUND Recent ecophysiological studies aimed at explaining adult tree mortality during drought have examined the carbon (C)-exhaustion compared to the hydraulic-failure hypotheses for death. Prolonged drought leads to durations of stomatal closure (and thus limited C gain), which could result in long periods of negative C balance and fatal reductions in whole-plant C reserves (i.e., available non-structural carbohydrates ["NSC"]). Alternatively, C reserves may not decrease much but could become increasingly inaccessible to sink tissues in long dry-periods due to impediments to translocation of photosynthate (e.g., through disruption of hydrostatic pressure flow in phloem). As C reserves decline or become inaccessible, continued maintenance respiration has been hypothesized to lead to exhaustion of NSC after extended durations of drought, especially in isohydric plant species. On the other hand, hydraulic failure (e.g., catastrophic xylem embolisms) during drought may be the proximate cause of death, occurring before true C starvation occurs. Few studies have investigated specifically the mechanism(s) of tree death, and no published studies that we know of have quantified changes in NSC during mortality. EXPERIMENTAL DESIGN AND HYPOTHESES We conducted two studies that investigated whole-tree and tissue-specific C relations (photosynthetic C gain, respiration, dry-mass gain, and NSC pools) in Pinus flexilis seedlings during the initial establishment phase, which is characterized by progressive drought during summer. We measured survival, growth and biomass allocation, and C-balance physiology (photosynthetic C-gain and chlorophyll fluorescence, respiration C-use, and NSC concentrations) from germination to mortality. We hypothesized that 1) stomatal and biochemical limitations to C gain would constrain seedling survival (through inadequate seasonal C-balance), as has been shown for conifer seedlings near alpine treeline; 2) hydraulic constraints (embolisms and

  6. Heat shock protein Hsp90-2 expression in the Arabidopsis thaliana seedlings under clinorotation

    Science.gov (United States)

    Kozeko, Liudmyla

    Heat shock proteins 90 kDa (Hsp90) are abundant under normal conditions and induced by stress. This family is distinguished from other chaperones in that most of its substrates are signal transduction proteins. Previously, we determined some time-dependent increase in the Hsp90 level in pea seedlings in response to simulated microgravity that indicated a stress-reaction. However, expression of the individual members of the Hsp90 family have specific pattern. The purpose of this study was to investigate possible alterations in the gene expression pattern of cytosolic Hsp90-2 in Arabidopsis thaliana seedlings under 2D-clinorotation. To obtain detailed expression pattern of the HSP90-2 genes we used seeds that provides a resource of loss-of-function mutations gene expression patterns via translational fusions with the reporter gene, GUS (a line N 166718, NASC). There were two variants of the experiment: 1) seedlings grew under clinorotation for 10, 12, 14 d; 2) seedlings grew in the stationary conditions for 10 d followed by clinorotation for 3 h -at 22o C and 16h light cycle. The seedlings grown in the stationary conditions were used as a control. GUS staining showed that HSP90-2 expression was regulated during seedling development and affected by clinorotation in the heterozygous mutant plants. In the homozygous for the mutation plants, HSP90-2 expression was stable during seedling development and not affected by clinorotation. GUS staining was observed in cotyledons, leaves and hypocotyls of the seedlings (especially intense in vascular bundles), indicating intensive cellular processes with participation of this chaperone. Possible pathways of influence of clinorotation on HSP90-2 expression are discussed.

  7. Carbon dynamics of Acer pseudoplatanus seedlings under drought and complete darkness.

    Science.gov (United States)

    Piper, Frida I; Fajardo, Alex

    2016-11-01

    Carbon (C) storage is considered a key component to plant survival under drought and shade, although the combined effects of these factors on survival remain poorly understood. We investigated how drought and shade alter the C dynamics and survival of tree seedlings, and whether drought limits the access to or usage of stored C. We experimentally applied two levels of soil humidity (well-watered versus drought, the latter induced by dry-down) and light availability (light versus complete darkness) on 1-year-old seedlings of Acer pseudoplatanus L. for 3 months. We quantified the survival, biomass, growth rate and non-structural carbohydrates (NSC) of seedlings at their time of death or at the end of the experiment for those that survived. We found that the soil dried out faster when drought was combined with light than when it was combined with complete darkness. Seedlings subjected to both drought and light showed reduced growth and reached 100% mortality earlier than any other treatment, with the highest NSC concentrations at the time of death. Seedlings exposed to both drought and complete darkness died significantly earlier than seedlings exposed to complete darkness only, but had similar NSC concentrations at time of their death, suggesting that drought accelerated the use of stored C under complete darkness. Complete darkness significantly reduced seedling growth and whole-plant NSC concentrations regardless of soil humidity, while root NSC concentrations were significantly more reduced when complete darkness was combined with drought conditions. Thus, the C dynamics in A. pseudoplatanus seedlings under complete darkness was not hindered by drought, i.e., the access and use of stored C was not limited by drought. The contrasting growth and C storage responses driven by drought under light versus complete darkness are consistent with a key role of the drought progression in the C dynamics of trees. © The Author 2016. Published by Oxford University Press. All

  8. Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

    Science.gov (United States)

    Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

    2009-01-01

    Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

  9. Starch bioengineering affects cereal grain germination and seedling establishment

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel

    2014-01-01

    Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...... structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics...... showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated...

  10. Seed loss and volunteer seedling establishment of rapeseed in the northernmost European conditions: potential for weed infestation and GM risks

    Directory of Open Access Journals (Sweden)

    Pirjo Peltonen-Sainio

    2014-11-01

    Full Text Available Rapeseed soil seed bank development and volunteer plant establishment represent substantial risk for crop infestation and GM contamination. This study was designed to complement such investigations with novel understanding from high latitude conditions. Four experiments were designed to characterise seed loss at harvest, persistence, viability and capacity for volunteer seedling establishment, as well as impact of management measures on soil seed bank dynamics. Oilseed rape was the primary crop investigated due to the availability of GM cultivars and because of the increasing importance. Harvest losses and soil seed bank development were significant. Volunteer seedlings emerged at reasonably high rates, especially in the first autumn after harvest, but about 10% of buried seeds maintained their viability for at least three years. Soil incorporation methods had no major effect on numbers of volunteer seedlings, but herbicide treatments controlled volunteer seedlings efficiently, though not completely, due to irregular timing of seedling emergence.

  11. The Wood and Bark of Hardwoods Growing on Southern Pine Sites - A Pictorial Atlas

    Science.gov (United States)

    Charles W. McMillin; Floyd G. Manwiller

    1980-01-01

    Provides a pictorial description of the structure and appearance of 23 pine-site hardwoods, an overview of hardwood anatomy, and data on the resource and certain important physical properties of stemwood and bark.

  12. Seedling recruitment of Colophospermum mopane on the Highveld ...

    African Journals Online (AJOL)

    Seedling recruitment of Colophospermum mopane on the Highveld of Zimbabwe: research note. ... Open areas with bare ground or sparse grass cover were favourable sites for seedling recruitment. Seedlings ... AJOL African Journals Online.

  13. Low power continuous wave-laser seed irradiation effect on Moringa oleifera germination, seedling growth and biochemical attributes.

    Science.gov (United States)

    Urva; Shafique, Hina; Jamil, Yasir; Haq, Zia Ul; Mujahid, Tamveel; Khan, Aman Ullah; Iqbal, Munawar; Abbas, Mazhar

    2017-05-01

    Recently, laser application in agriculture has gained much attention since plant characteristics were improved significantly in response of pre-sowing seed treatment. Pre-sowing laser seed treatment effects on germination, seedling growth and mineral profile were studied in Moringa olifera. M. olifera healthy seeds were exposed to 25, 50, 75mJ low power continuous wave laser light and grown under greenhouse conditions. The seedling growth and biochemical attributes were evaluated from 10-day-old seedlings. The germination parameters (percentage, mean germination time), vigor index, seedling growth (root length, seedling length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight) enhanced considerably. The laser energy levels used for seed irradiation showed variable effects on germination, seedling growth and mineral profile. The mineral contents were recorded to be higher in seedling raised from laser treated seeds, which were higher in roots versus shoots and leaves. The effect of laser treatment on seedling fat, nitrogen and protein content was insignificant and at higher energy level both nitrogen and protein contents decreased versus control. Results revealed that M. olifera germination, seedling growth and mineral contents were enhanced and optimum laser energy level has more acceleratory effect since at three laser energy levels the responses were significantly different. Overall the laser energy levels effect on germination and seedling growth was found in following order; 75mJ>50mJ>25mJ, where as in case of fat, protein and nitrogen contents the trend was as; 25mJ>50mJ and 75mJ. However, this technique could possibly be used to improve the M. olifera germination, seedling growth, and minerals contents where germination is low due to unfavorable conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Increased acidification in the rhizosphere of cactus seedlings induced by Azospirillum brasilense

    Science.gov (United States)

    Carrillo, Angel; Li, Ching; Bashan, Yoav

    2002-08-01

    Acidification of the rhizosphere of cactus seedlings (giant cardon, Pachycereus pringlei) after inoculation with the plant growth-promoting bacterium Azospirillum brasilense Cd, in the presence or absence of ammonium and nitrate, was studied to understand how to increase growth of cardon seedlings in poor desert soils. While ammonium enhanced rhizosphere and liquid culture acidification, inoculation with the bacteria enhanced it further. On the other hand, nitrate increased pH of the rhizosphere, but combined with the bacterial inoculation, increase in pH was significantly smaller. Bacterial inoculation with ammonium enhanced plant growth.

  15. Effects of Corn Canopy on Seedling Emergence of Seven Weed Species

    Directory of Open Access Journals (Sweden)

    F Kordbacheh

    2012-02-01

    Full Text Available In this research corn were planted in 3 densities (8, 12, 16 plant/m2 in two planting patterns (single and double-row with seven summer weed species, including redroot pigweed, green foxtail, annual bluegrass, common lambsquarter, jimsonweed, black nightshade and johnsongrass were planted. Temperature, quality and quantity of light reaching to soil surface were measured and the number of emerged seedlings for each weed species was countered in three sampling dates. Temperature fluctuation wasn't affected by density and planting patterns and was reduced with canopy formation. In all weed species 3 seedling emergence patterns were observed. In small seed species, redroot pigweed had one germination flush, so it was not respond to crop canopy. The number of emerged weed seedlings of annual bluegrass, common lambsquarter and green foxtail were significantly higher in bareground than under corn canopy. In double-row planting pattern was higher compared to the single-row and had three germination flushes. The number of emerged seedlings in the species with relatively large seeds had no significant difference between bareground and under corn canopy in jimsonweed and black nightshade. But it increased in johnsongrass under corn canopy compare to the bare ground. In all three species it was higher in double-row compare to single-row pattern. Jimsonweed had three germination flushes but blacknightshade and johnsongrass had 1 germination flush.

  16. Hydrogen sulphide improves adaptation of Zea mays seedlings to iron deficiency.

    Science.gov (United States)

    Chen, Juan; Wu, Fei-Hua; Shang, Yu-Ting; Wang, Wen-Hua; Hu, Wen-Jun; Simon, Martin; Liu, Xiang; Shangguan, Zhou-Ping; Zheng, Hai-Lei

    2015-11-01

    Hydrogen sulphide (H2S) is emerging as a potential molecule involved in physiological regulation in plants. However, whether H2S regulates iron-shortage responses in plants is largely unknown. Here, the role of H2S in modulating iron availability in maize (Zea mays L. cv Canner) seedlings grown in iron-deficient culture solution is reported. The main results are as follows: Firstly, NaHS, a donor of H2S, completely prevented leaf interveinal chlorosis in maize seedlings grown in iron-deficient culture solution. Secondly, electron micrographs of mesophyll cells from iron-deficient maize seedlings revealed plastids with few photosynthetic lamellae and rudimentary grana. On the contrary, mesophyll chloroplasts appeared completely developed in H2S-treated maize seedlings. Thirdly, H2S treatment increased iron accumulation in maize seedlings by changing the expression levels of iron homeostasis- and sulphur metabolism-related genes. Fourthly, phytosiderophore (PS) accumulation and secretion were enhanced by H2S treatment in seedlings grown in iron-deficient solution. Indeed, the gene expression of ferric-phytosiderophore transporter (ZmYS1) was specifically induced by iron deficiency in maize leaves and roots, whereas their abundance was decreased by NaHS treatment. Lastly, H2S significantly enhanced photosynthesis through promoting the protein expression of ribulose-1,5-bisphosphate carboxylase large subunit (RuBISCO LSU) and phosphoenolpyruvate carboxylase (PEPC) and the expression of genes encoding RuBISCO large subunit (RBCL), small subunit (RBCS), D1 protein (psbA), and PEPC in maize seedlings grown in iron-deficient solution. These results indicate that H2S is closely related to iron uptake, transport, and accumulation, and consequently increases chlorophyll biosynthesis, chloroplast development, and photosynthesis in plants. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. Examination of worldwide hardwood lumber production, trade, and apparent consumption: 1995-2013

    Science.gov (United States)

    William G. Luppold; Matthew S. Bumgardner

    2015-01-01

    Worldwide hardwood lumber production fluctuated between 1995 and 2013 and changed considerably with respect to regional market shares. Similarly, worldwide hardwood lumber imports and exports have been constantly changing. Understanding these changes is important because collectively, they define the hardwood lumber consumption of a region or country. In 1995, North...

  18. Decision Criteria for German Hardwood Lumber Buyers: Market Needs and Purchase

    Science.gov (United States)

    Thomas G. Ponzurick; Robert J. Bush; Dieter Schaupp; Philip A. Araman

    1993-01-01

    The purpose of this study was to develop a better understanding of hardwood exports to the German market. A mail survey was conducted which resulted in a 47.8 percent rate of response. Of those German hardwood buyers responding to the survey, 71 percent purchased hardwood lumber directly from North America.

  19. Impacts of changing hardwood lumber consumption and price on stumpage and sawlog prices in Ohio

    Science.gov (United States)

    William Luppold; Matthew Bumgardner; T. Eric. McConnell

    2014-01-01

    In the early 2000s, increasing US furniture imports preceded declining US hardwood lumber demand and price. In the summer of 2002, however, hardwood lumber prices started to increase as demand by construction industries increased. By the mid-2000s, hardwood lumber prices hit all-time highs. Lumber prices hit all-time highs for red oak (Quercus spp...

  20. Marketing low-grade hardwoods for furniture stock - a new approach

    Science.gov (United States)

    Hugh W. Reynolds; Charles J. Gatchell

    1979-01-01

    A hardwood shortage of high-grade lumber exists while there is a surplus of low-grade hardwood timber. Two things are needed for the surplus to correct the shortage: a new manufacturing system and a new marketing technique. Utilization research at the Princeton Forestry Sciences Laboratory has developed the new system for converting low-grade hardwood for furniture use...

  1. The changing structure of the hardwood lumber industry with implications on technology adaptation

    Science.gov (United States)

    William Luppold; John Baumgras; John Baumgras

    2000-01-01

    The hardwood sawmilling industry has been changing over the last 50 years as a result of changes in hardwood sawtimber inventory and in the demand for hardwood lumber. In 1950 the industry was composed of numerous individual mills, few of which produced more than 3 million board feet of lumber annually. During this time the furniture industry was the major user of...

  2. Genetic improvement of hardwood fiber production in the north-central region: potentials and breeding alternatives

    Science.gov (United States)

    R.E., Jr. Farmer

    1973-01-01

    In the Lake States, aspens are now growing towards senility Faster than they are being harvested (Groff 1966). In the Central States, wood processing residues have recently supplied about one-half of the area's hardwood fiber requirement (Blyth 1970), thus allowing hardwood growing stock to continue its recuperation. In fact, the national hardwood fiber supply...

  3. A Comparison of Market Needs to the Species and Quality Composition of the Eastern Hardwood

    Science.gov (United States)

    Robert J. Bush; Philip A. Araman

    1991-01-01

    Many markets for hardwood lumber have experienced growth in recent years. Eastern and Central hardwood lumber production reached an estimated 11.2 billion board feet in 1988, a twenty year high. Wood furniture, flooring, and exports have also experienced growth in the last ten years. During the same period, annual growth on eastern hardwood forests has exceeded annual...

  4. Germination and Seedling Development of Seeds from Different Parkia biglobosa (Jacq G. Don Trees

    Directory of Open Access Journals (Sweden)

    Christiana O. ADEYEMI

    2013-02-01

    Full Text Available The effect of daylight, continuous illumination and acid scarification on the seed germination and seedling vegetative growth (epicotyl and hypocotyl lengths, and number of secondary roots of different Parkia biglobosawere investigated in the Plant Physiology Laboratory University of Ilorin, Ilorin Kwara State Nigeria. Seeds from two out of the twenty six Parkia tree samples (trees B and T germinated within 24 hours of planting in the daylight germination study while seeds from another tree (Q did not germinate until the third week after planting (3WAP. Some seeds have higher germination percentage both in the daylight (preliminary germination study and in the continuous light (illuminated study. The treatment with concentrated Sulphric acid (conc. H2SO4was effective in breaking the seed dormancy as seeds from eight (8 trees produced one hundred percent (100% germination. At p= 0.05 the length of epicotyl and hypocoty1 lengths were significantly different as seedling vegetative growth were long in the seedlings from the daylight experiment than the continuous light experiment. The vegetative growths of the seedlings from the scarified seed were longer at 15min of scarification in all except in trees F and Z. It was observed that the time of scarification affect the both seed germination and seedling development.

  5. The impact of the herbicide atrazine on growth and photosynthesis of seagrass, Zostera marina (L.), seedlings.

    Science.gov (United States)

    Gao, Yaping; Fang, Jianguang; Zhang, Jihong; Ren, Lihua; Mao, Yuze; Li, Bin; Zhang, Mingliang; Liu, Dinghai; Du, Meirong

    2011-08-01

    The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  6. PHYSIOLOGICAL AND FOLIAR INJURY RESPONSES OF PRUNUS SEROTINA, FRAXINUS AMERICANA, AND ACER RUBRUM SEEDLINGS TO VARYING SOIL MOISTURE AND OZONE. (R825244)

    Science.gov (United States)

    Sixteen black cherry (Prunus serotina, Ehrh.), 10 white ash (Fraxinus americana, L.) and 10 red maple (Acer rubrum, L.) 1-year old seedlings were planted per plot in 1997 on a former nursery bed within 12 open-top chambers and six open plots. Seedlings wer...

  7. Direct and indirect effects of a dense understory on tree seedling recruitment in temperate forests: habitat-mediated predation versus competition

    Science.gov (United States)

    Alejandro A. Royo; Walter P. Carson

    2008-01-01

    In forests characterized by a dense woody and herbaceous understory layer, seedling recruitment is often directly suppressed via interspecific competition. Alternatively, these dense layers may indirectly lower tree recruitment by providing a haven for seed and seedling predators that prey on neighboring plant species. To simultaneously...

  8. Allelopathic activity of Leonurus siribicus L. on seed germination and seedling growth of wheat and identification of 4- hydroxy benzoic acid as an allelochemical by chromatography

    International Nuclear Information System (INIS)

    Sayed, M. A.; Imam, R.; Siddiqui, M.N.

    2016-01-01

    The aim of this study was to investigate the allelopathic effects of L. siribicus extract on seed germination and seedlings growth of wheat as well as to identify potential allelochemical. The different concentration (5, 10 and 15%) of aqueous extract were applied during the time of sowing and at 5 days after sowing of wheat seed. L. siribicus extract showed concentration and time - depending activity. Different concentration of aqueous extract inhibited seed germination, seedlings growth, when extracts were applied during the time of seed sowing. The stimulatory effect of seedlings growth were found for 5 % aqueous extract, in contrast 10 and 15% extract inhibited seedlings growth, when extracts were applied at 5 days after sowing. Apart from, 4-hydroxy benzoic acids affected seedlings growth irrespective of application time. The weight of dry matter of wheat seedlings were increased for 5% than 10 and 15% extracts. Thin layer chromatography suggested that the presence of 4-hydroxy benzoic acid including other allelopathic and growth regulatory compounds inhibited germination and seedlings growth. Mineral composition was determined and its might have some stimulatory effect on seedlings growth. It was interesting that 5% extract inhibited germination and seedlings growth, when it was applied during the time of seed sowing, but stimulated seedling growth, when it was applied at 5 days after sowing. The extract of this plants can be used either for bioherbicide as well as growth stimulatory agents for the organic farming system. To find out molecular mechanism behind it, further research is to be done. (author)

  9. Overstory density affects field performance of underplanted red oak (Quercus rubra L.) in Ontario

    Science.gov (United States)

    Daniel C. Dey; William C. Parker

    1997-01-01

    Red oak seedlings were underplanted in a closed-canopy mature northern hardwood stand and an adjacent shelterwood in central Ontario. Overstory density effects on seedling survival and growth were assessed 2 yr after planting. After 2 yr, seedling survival was 90% in the uncut stand and over 99% in the shelterwood. Seedlings in the uncut stand experienced negligible or...

  10. ADDING ECOLOGICAL REALISM TO PLANT TESTING

    Science.gov (United States)

    Current test protocols for the protection of nontarget plants used when registering pesticides in the United States and many other countries depend on two tests using greenhouse grown, agricultural seedling plants. The seedling emergence and vegetative vigor tests are used to as...

  11. Fungos endofíticos em Annona spp.: isolamento, caracterização enzimática e promoção do crescimento em mudas de pinha (Annona squamosa L. Endophytic fungi of Annona spp.: isolation, enzymatic characterization of isolates and plant growth promotion in Annona squamosa L. seedlings

    Directory of Open Access Journals (Sweden)

    Roberta Lane de Oliveira Silva

    2006-09-01

    Full Text Available A partir de folhas, caules e raízes de plantas de pinha e graviola coletadas em Pernambuco foram obtidos 110 e 90 isolados fúngicos endofíticos, respectivamente. Vinte e nove isolados foram selecionados e avaliados quanto à produção de enzimas extracelulares, através do método qualitativo em placas com meios sólidos específicos, e à capacidade de estimular o crescimento de mudas de pinha. Esses isolados foram identificados como pertencentes aos gêneros Acremonium (10,34%, Aspergillus (3,45%, Chaetomium (3,45%, Colletotrichum (10,34%, Cylindrocladium (13,8%, Fusarium (31,03%, Glomerella (3,45%, Nigrospora (6,9%, Penicillium (6,9% e Phomopsis (10,34%. Dezenove isolados apresentaram atividade lipolítica, cinco atividade proteolítica e nenhum deles atividades celulolítica ou amilolítica. Onze isolados dos gêneros Acremonium (GFR6 e GRR1, Colletotrichum (GFR4 e PFR4, Phomopsis (PFR3 e GCR4, Cylindrocladium (GRR4, Chaetomium (GRR7 e Fusarium (GRR5, PRR1 e PRR6 promoveram eficientemente o crescimento vegetal. Os índices de aumento da biomassa seca da parte aérea de mudas de pinha variou de 23,2 a 32,7%, sendo que nenhum isolado promoveu a biomassa seca da raiz. Destaca-se também que 20 isolados apresentaram efeito deletério significativo (P = 0,05 na biomassa seca da raiz das mudas de pinha. Em tecidos aparentemente sadios de plantas de pinha e graviola são encontrados alguns fungos que podem promover o crescimento da parte aérea, como também reduzir o crescimento da raiz e outros sem efeito no crescimento de mudas de pinha.Endophytic isolates of fungi were obtained from leaves, stems and roots of 110 sweetsop and 90 soursop plants from Pernambuco. Twenty-nine isolates were analyzed for production of extracellular enzymes by qualitative assay in Petri dishes containing specific solid media, and for the capacity to promote growth of sweetsop seedlings. These isolates were identified as Acremonium (10.34%, Aspergillus (3

  12. Effect of lead on nucleic acid and protein contents of rice (Oryza sativa L. ) seedlings and its interaction with IAA and GA/sub 3/ in different plant systems

    Energy Technology Data Exchange (ETDEWEB)

    Maitra, P.; Mukherh, S.

    1979-09-01

    Activity of lead acetate, (CH/sub 3/COO)/sub 2/Pb, 3 H/sub 2/O, was studied in germinating rice seedlings with respect to RNA, DNA and alkali soluble protein contents. RNA, DNA and protein contents greatly reduced both in embryo and endosperm with increasing concentrations of lead and with concomitant increase in amino acid content in embryo. When IAA was supplied in combination with lead acetate, variable amounts of relief of elongation inhibition of wheat coleoptile sections were noticed. With GA/sub 3/, however, lead-induced inhibition of either lettuce (Lactuca sativa L.) hypocotyl elongation or ..cap alpha..-amylase production in rice half seeds was largely overcome.

  13. Antioxidant properties of soybean seedlings inoculated with Trichoderma asperellum

    Directory of Open Access Journals (Sweden)

    Manojlović Ana S.

    2017-01-01

    Full Text Available This study was conducted in order to assess the effect of inoculation of soybean (Glycine max L. seeds with Trichoderma asperellum, followed by mites (Tetranychus urticae exposure on lipid peroxidation (LP process and the activity of antioxidant enzymes. T. urticae is an occasional pest of soybean that causes biotic stress. Biotic stress leads to overproduction of reactive oxygen species (ROS which may cause damage to vital biomolecules. Enzymatic antioxidant defense systems protect plants against oxidative stress. T. asperellum is commonly used as biocontrol agent against plant pathogens. It has been suggested that previous inoculation of seeds with T. asperellum may cause induced resistance against biotic stress. The aim of this study was to determine LP intensity and antioxidant enzymes activity in inoculated and non-inoculated soybean seedlings with and without exposure to mites. Noticeably higher LP intensity was detected in non-inoculated group treated with mites compared to control group. Inoculated soybean seedlings treated with mites had lower LP intensity compared to noninoculated group. Also, it has been noticed that inoculation with Trichoderma asperellum itself, produced mild stress in plants. In addition, positive correlation between enzymes activity and LP was noticed. The level of oxidative stress in plants was followed by the change of LP intensity. According to results obtained, it was concluded that the greatest oxidative stress occurred in non-inoculated group treated with mites and that inoculation successfully reduced oxidative stress. The results indicate that inoculation of soybean seeds with T. asperellum improves resistance of soybean seedlings against mites attack. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31022

  14. Diversity of seedling responses to drought

    NARCIS (Netherlands)

    Slot, M.; Poorter, L.

    2007-01-01

    Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist

  15. Final Report: N-Acylethanolamine metabolism and the acquisition of photoautotrophy during seedling establishment

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Kent

    2018-01-29

    Research in our labs, supported since 2005 by Basic Energy Sciences, has led to the discovery of a new lipid mediator pathway that influences phytohormone-mediated regulation of plant growth and development—the so-called N-acylethanolamine (NAE) regulatory pathway. This pathway in plants shares conserved metabolic machinery with the endocannabinoid signaling system of vertebrates that regulates a multitude of physiological and behavioral processes in mammals, suggesting that the metabolism of NAEs is an important regulatory feature of eukaryotic biology. Current evidence in plants points to interactions between NAE metabolism, abscisic acid (ABA) signaling and light signaling to modulate seedling establishment and the acquisition of photoautotrophic growth. The proposed research fits well within the mission of Photosynthetic Systems and Physical Biosciences which seek “to understand the processes by which plants, algae and non-medical microbes capture, convert and/or store energy”. The fundamental regulatory processes that govern seedling establishment directly influence the assembly of photosynthetic energy conversion systems in essentially all higher plants. Our main hypothesis is that seedlings coordinate the metabolic depletion of NAEs during seedling establishment through a complex interaction of hydrolysis (by fatty acid amide hydrolase, FAAH) and oxidation (by lipoxygenases, LOX) and that newly-reported oxylipin metabolites of polyunsaturated NAEs help to coordinate seedling development and acquisition of photoautotrophy in response to appropriate environmental cues. Evidence suggests that ethanolmide oxylipins derived from NAEs can reversibly accumulate in seedlings and adjust/arrest seedling establishment and chloroplast development in conjunction with ABA signaling and light-signaling pathways. Our results provide important new information linking the production of small molecule lipid mediators in seedlings to the coordinated development of

  16. Effect of Acinetobacter sp on metalaxyl degradation and metabolite profile of potato seedlings (Solanum tuberosum L. alpha variety.

    Directory of Open Access Journals (Sweden)

    Fabiola G Zuno-Floriano

    Full Text Available One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC-TOF-MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism.

  17. Factors influencing changes in U.S. hardwood log and lumber exports from 1990 to 2011. BioResources

    Science.gov (United States)

    William G. Luppold; Matthew S. Bumgardner

    2013-01-01

    Domestic consumption of hardwood products in the United States since 2000 has trended downward, making exports the single most important market for higher grade hardwood lumber and a major market for higher value hardwood logs. Between 1990 and 2011, hardwood lumber exports increased by 46%. During most of this period, Canada was the largest export market for U.S....

  18. Interactive effects of rice residue and water stress on growth and metabolism of wheat seedlings

    Directory of Open Access Journals (Sweden)

    Nimisha Amist

    2014-08-01

    Full Text Available In the present study effects of rice residue with and without water stress were studied on Triticum aestivum L. cv. Shatabadi. The mixture of residue and garden soil in 1:1 ratio was considered as 50% (R1 and only decomposed residue as 100% (R2. Garden soil was taken as control. Twenty five seeds were sown in each experimental trays filled with soil mixture according to the treatments. Trays were arranged in two groups. After 15 days one set was subjected to water stress (WS by withholding water supply for 3 days. Morphological and biochemical parameters of 18 days old seedlings were recorded. Seedling height decreased in all treatments. A gradual decrease in relative water content, pigment and protein contents of wheat seedlings were observed. Sugar and proline contents increased in treatments. An increase in malondialdehyde (MDA content and antioxidative enzyme activities was recorded. Elevation in catalase activity was observed in all treatments except in plants with water deficit. Ascorbate peroxidase (APX and guaiacol peroxidase (GPX activities increased when residue mixed with soil but decreased in seedlings under the combined influence of the residue and water stress. Higher amount of MDA and lower activities of APX and GPX reflected the oxidative damage in seedlings under combined treatments. Rice residue inhibited growth of wheat seedlings. Water stress intensified the effects of residue.

  19. Hydraulic redistribution of water from Pinus ponderosa trees to seedlings: evidence for an ectomycorrhizal pathway.

    Science.gov (United States)

    Warren, Jeffrey M; Brooks, J Renée; Meinzer, Frederick C; Eberhart, Joyce L

    2008-01-01

    While there is strong evidence for hydraulic redistribution (HR) of soil water by trees, it is not known if common mycorrhizal networks (CMN) can facilitate HR from mature trees to seedlings under field conditions. Ponderosa pine (Pinus ponderosa) seedlings were planted into root-excluding 61-microm mesh barrier chambers buried in an old-growth pine forest. After 2 yr, several mature trees were cut and water enriched in D(2)O and acid fuchsin dye was applied to the stumps. Fine roots and mycorrhizal root tips of source trees became heavily dyed, indicating reverse sap flow in root xylem transported water from stems throughout root systems to the root hyphal mantle that interfaces with CMN. Within 3 d, D(2)O was found in mesh-chamber seedling foliage > 1 m from source trees; after 3 wk, eight of 10 mesh-chamber seedling stem samples were significantly enriched above background levels. Average mesh-chamber enrichment was 1.8 x greater than that for two seedlings for which the connections to CMN were broken by trenching before D(2)O application. Even small amounts of water provided to mycorrhizas by HR may maintain hyphal viability and facilitate nutrient uptake under drying conditions, which may provide an advantage to seedlings hydraulically linked by CMN to large trees.

  20. Short Communication. Physiological effects of Rhizopogon Roseolus on Pinus halepensis seedlings

    Directory of Open Access Journals (Sweden)

    J.A. Alfonso Domínguez Núñez

    2013-12-01

    Full Text Available Aim of study: The inoculation of forest seedlings with ectomycorrhizal fungi can improve the morphological and physiological qualities of plants, especially those used for regeneration of arid areas. Rhizopogon roseolus is an ectomycorrhizal fungus (ECM commonly used for reforestation. In this study, the specific objectives were to know some morphophysiological effects of Rhizopogon Roseolus on Pinus halepensis seedlings under standard nursery conditionsArea of study: ETSI Montes and EUIT Forestal, Madrid.Material and Methods: In nursery, under well watered conditions and peat growing substrates, Aleppo pine seedlings were inoculated with R. roseolus. Five months after the inoculations, we examined the growth, water parameters (osmotic potential at full turgor [Ψπfull], osmotic potential at zero turgor [Ψπ0], and the tissue modulus of elasticity near full turgor [Emax], mycorrhizal colonization, and concentration and content of macronutrients in the seedlings. Subsequently, a trial was conducted to assess the root growth potential.Main results: The mycorrhization decreased the height and diameter of mycorrhizal seedlings but increased the root weight and root branching. R. roseolus did not cause any significant effect on the regeneration of new roots or on any of the tested hydric parameters, but it did improve N uptake of the seedlings.Research highlights: The mycorrhizal inoculation increased the N uptake. The mycorrhizal inoculation caused opposite effects on some growth parametersKeywords: Osmotic adjustment; elastic adjustment; mineral nutrition; root growth potential; nursery; Rhizopogon roseolus;  Pinus halepensis. 

  1. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    Science.gov (United States)

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

  2. Early field performance of drought-stressed scots pine (pinus sylvestris l.) seedlings

    International Nuclear Information System (INIS)

    Kulac, S.; Clcek, E.; Tasdemir, U.

    2015-01-01

    Scots pine (Pinus sylvestris) has a large natural distribution throughout the world, including semi-arid areas of Turkey, where it is being used for afforestation. Determining the drought resistance of Scots pine provenances can increase the success of afforestation efforts in semi-arid regions. In the first stage of this study, water-stress treatments were applied to ten provenances of one-year-old Scots pine seedlings in their second vegetation period (between April and November). The diameter and height of the seedlings were evaluated in the nursery in order to determine their morphology. The four drought-stress treatments consisted of once-weekly irrigation (IR1), twice-weekly irrigation (IR2-Control), biweekly irrigation (IR3) and open field conditions (IR4). Later, the water-stressed seedlings were planted in a semi-arid district in Bayburt, Turkey, and their survival and growth performances were evaluated over a five-year period. The nursery study showed that drought stress and provenance as well as the interaction of the two significantly affected the morphological characteristics of the seedlings. Under water-stress conditions, the best growth performance was found in the Dokurcun, Degirmendere and Dirgine provenance seedlings. Water-stress and provenance factors and their interaction also affected the open field performance of the seedlings, where the Degirmendere, Dirgine and Dokurcun provenances again exhibited the best performance. Consequently, these Scots pine provenances can be recommended for afforestation sites having conditions similar to those of the study site. (author)

  3. Thirteen-year hardwood tree performance on a Midwest surface mine

    International Nuclear Information System (INIS)

    Ashby, W.C.; Kolar, C.A.

    1998-01-01

    Black walnut (Juglans nigra L.), sweetgum (Liquidambar styraciflua L.), tuliptree (Liriodendron tulipifera L.), white oak (Quercus alba L.), bur oak (Q. macrocarpa Michx.), and pin oak (Q. palustris Muenchh.) seedlings were planted both fall 1980 and spring 1981 on mixed overburden strip-mining banks (ungraded), mixed overburden graded to approximate original contour (AOC) (graded), mixed overburden graded to AOC wit h 60 cm of replaced pre-mining surface soil materials (topsoil), and on old fields near the strip-mine (unmined). Black walnut and pin oak were also planted as seed, with a total of 6000 seedlings/seed spots in the study. Initial species field viability ranged from 86 to 100%. With one exception, after 3 growing seasons oak seedlings had 50% or greater survival. Survival was mostly lower after 3 years with some additional mortality by years 8 and 13. Height and diameter breast height were measured after 13 years. Survival and growth of trees planted fall or spring was similar overall with variable performance by species. Seedlings of several species on the ungraded site had over 50% survival after 13 years, with fewer trees where planted as seed. Mean height of all species combined was significantly greater on the ungraded than on any other site and was lowest on the topsoil site. The unmined sites had high variability in species survival and height. Better reclamation with trees resulted from a deep, well-drained rooting medium with minimal compaction and a mineral-rich surface soil including coarse fragments over 2 mm in size for long-term productivity

  4. Response of some Citrus Rootstock Seedlings to Fertilization by the Aqueous Extract of some Irradiated Animal Manures

    International Nuclear Information System (INIS)

    Awad, S.M.

    2008-01-01

    A pot experiment was carried out during two consecutive seasons i.e. 2001 and 2002 on two citrus rootstocks namely Sour orange and Volkamer lemon seedlings two-month-old planted in a sandy soil under greenhouse to study the feasibility of using the aqueous extract of some animal manures i.e. poultry, sheep and cattle treated by gamma irradiation at 10 kGay to keep the manure free from pathogenic organisms, pests and weed seeds and as a natural source of nutrients instead of mineral fertilizers, and it's effect on growth and leaf nutrients content of seedlings. Generally, results showed that all the tested treatments enhanced most of growth parameters such as seedling height, stem diameter, root length, number of leaves/seedling, number of roots/seedling, and dry weight for both of stem, leaves, root and total dry weight/plant. Moreover, such treatments improved leaf nutrient content of both of Sour orange and Volkamer lemon seedlings. Meanwhile, seedlings fertilized by the aqueous extract of poultry manure achieved the highest values of growth parameters and leaf nutrients content as well as mineral fertilizer followed by those treated by the aqueous extract of both sheep and cattle manures

  5. Physico-chemical changes in karkade (Hibiscus sabdariffa L.) seedlings responding to salt stress.

    Science.gov (United States)

    Galal, Abdelnasser

    2017-03-01

    Salinity is one of the major abiotic stress factors affecting series of morphological, physiological, metabolic and molecular changes in plant growth. The effect of different concentrations (0, 25, 50, 100 and 150 mM) of NaCl on the vegetative growth and some physiological parameters of karkade (Hibiscus sabdariffa var. sabdariffa) seedling were investigated. NaCl affected the germination rate, delayed emergence and retarded vegetative growth of seedlings. The length of seedling as well as the leaf area was significantly reduced. The fresh weight remained lower in NaCl treated seedlings compared to control. NaCl at 100 and 150 mM concentrations had significant effect on the dry matter contents of the treated seedlings. The chloroplast pigments in the treated seedlings were affected, suggesting that the NaCl had a significant effect on the chlorophyll and carotenoid biosynthesis. The results showed that the salt treatments induced an increase in proline concentration of the seedlings. The osmotic potential (ψs) of NaCl treated seedlings decreased with increasing NaCl concentrations. Salt treatments resulted in dramatic quantitative reduction in the total sterol percent compared with control ones. Salt stress resulted in increase and decrease of Na + and K + ions, respectively. NaCl salinity increased lipid peroxidation. SDS-PAGE was used to evaluate protein pattern after applying salt stress. High molecular weight proteins were intensified, while low molecular weight proteins were faint. NaCl at 100 and 150 mM concentration distinguished with new protein bands. Salt stress induced a new peroxidase bands and increased the band intensity, indicating the protective role of peroxidase enzyme.

  6. Mechanisms of induction of cross thermo- and radioresitance of Zea mays seedlings

    International Nuclear Information System (INIS)

    Gikoshvili, T.I.; Beletskij, I.P.; Vilenchik, M.M.; Kuzin, A.M.

    1988-01-01

    Thermotolerance of plant seedlings was shown to be induced not only by their heating at 43 deg C but also by γ-irradiation with doses of 2 or 3 Gy, the kinetics of the tolerance development in both cases being similar to each other and to the kinetics of development of the radioresistance state induced by γ-radiation within the same dose range (1 to 3 Gy). This state did not develop in seedlings treated with cycloheximide, an inhibitor of protein synthesis. After a 15-minute heating at 43 deg C or γ-irradiation with a dose of 2 Gy, synthesis of some proteins was similarly activated, among which three had similar molecular mass. The data obtained suggest that γ-irradiation with low doses induces in plant seedlings the synthesis of proteins that can increase thermo- and radioresistance

  7. GROWTH AND NODULATION OF LEUCAENA AND PROSOPIS SEEDLINGS IN SOIL PLUS TANNERY SLUDGE

    Directory of Open Access Journals (Sweden)

    Ademir Sérgio Ferreira de Araújo

    2006-01-01

    Full Text Available The objective of this paper was to evaluate the growth and nodulation of Leucaena and Prosopis seedlings in soil plus tannery sludge. The study was conducted in a greenhouse, using bags containing soil plus tannery sludge. Seedlings of Leucaena and Prosopis inoculated with Bradyrhizobium sp were used. Results were evaluated 90 days after plant emergency. The application of tannery sludge, in the rate of 11.250 kg per hectare significantly increased plant height, stem diameter, and above ground dry mass ofLeucaena. Regarding Prosopis, there were no significant increases in these variables with tannery sludge application, except for aerial dry mass. No significant differences were seen between the treatments with sludge and inoculated with Bradyrhizobium sp. as to nodule number and dry mass. Tannery sludge evaluated in this work did not affect nodulation, besides favoring Leucaena and Prosopis seedling growth.

  8. Mechanism of artemisinin phytotoxicity action: induction of reactive oxygen species and cell death in lettuce seedlings.

    Science.gov (United States)

    Yan, Zhi-Qiang; Wang, Dan-Dan; Ding, Lan; Cui, Hai-Yan; Jin, Hui; Yang, Xiao-Yan; Yang, Jian-She; Qin, Bo

    2015-03-01

    Artemisinin has been recognized as an allelochemical that inhibits growth of several plant species. However, its mode of action is not well clarified. In this study, the mechanism of artemisinin phytotoxicity on lettuce seedlings was investigated. Root and shoot elongation of lettuce seedlings were inhibited by artemisinin in a concentration-dependent manner. The compound effectively arrested cell division and caused loss of cell viability in root tips of lettuce. Overproduction of reactive oxygen species (ROS) was induced by artemisinin. Lipid peroxidation, proline overproduction and reduction of chlorophyll content in lettuce seedlings were found after treatments. These results suggested that artemisinin could induce ROS overproduction, which caused membrane lipids peroxidation and cell death, and impacted mitosis and physiological processes, resulting in growth inhibition of receptor plants. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. In vitro germination and acclimatization of cambui tree type seedlings

    Directory of Open Access Journals (Sweden)

    Ana da Silva Lédo

    2014-01-01

    Full Text Available There are few reports in literature on the in vitro behavior of cambui tree (Myrciaria tenella O. Berg and acclimatization conditions. The aim of this study was to evaluate the effect of culture media on in vitro germination and the effect of different substrates on the acclimatization of two Myrciaria tenella types. The study was carried out at the Embrapa Tabuleiros Costeiros Laboratory of Plant Tissue Culture, Aracaju, SE. Seeds were extracted from fruits of two Myrciaria tenella types: Orange and Purple Types. The seeds were inoculated in the following culture media: T1 - MS medium + 30g L -1 sucrose, T2 - 1/2 MS medium + 15g L -1 sucrose and T3 - control without MS salts. To study the effect of substrates on acclimatization, seedlings were transferred to plastic containers with capacity of 300cm 3 containing the following sterilized substrates: S1 - soil and powdered coconut husk - SPC (1:1 by volume; S2 - soil, washed sand and powdered coconut husk - SAPC (1:1:1 by volume and S3 - Biomix (r commercial substrate - SC. The medium without MS salts promoted 100% in vitro germination and 1/2 MS medium greater development of seedlings. All substrates studied are suitable for acclimatization of seedlings germinated in vitro. Myrciaria tenella of yellow type showed greater vigor during acclimatization.

  10. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2015-01-01

    Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.

  11. Fungi of the genus Fusarium as pathogens of soybean seedlings

    Directory of Open Access Journals (Sweden)

    Joanna Marcinkowska

    2013-12-01

    Full Text Available Twenty isolates of fungi of the genus Fusarium collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species F. culmorum was most numerously represented among the isolated (4 of 8 pathogens. Isolates of F. sambucinum were also pathogenic (2 of 4 and those of F. soloni (1 of 3, too. The only isolate of F. avenaceum also caused seedling blight. Two isolates of F. oxysporum and two of F. arthrosporioides were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

  12. Continuous measurement of stem-diameter growth response of Pinus pinea seedlings mycorrhizal with Rhizopogon roseolus and submitted to two water regimes.

    Science.gov (United States)

    Parladé, Javier; Cohen, Moshe; Doltra, Jordi; Luque, Jordi; Pera, Joan

    2001-08-01

    Linear variable differential transformer (LVDT) sensors were used to detect continuous diameter growth responses of Pinus pinea (stone pine) seedlings inoculated with the ectomycorrhizal fungus Rhizopogon roseolus. Colonised and non-colonised seedlings provided with sensors were submitted to different water regimes in two consecutive experiments established in a controlled-temperature greenhouse module (cycle 1), and in an adjacent module without temperature control (cycle 2). Under regular irrigation, colonised seedlings showed significantly higher growth than non-colonised seedlings. Water-stressed seedlings showed no benefit from inoculation in terms of growth. Also, seedlings with a high colonisation level recovered more slowly from water stress than control seedlings. A significant positive relationship between maximum daily shrinkage (amplitude of the daily stem contraction) and global radiation was observed only in the first water-stress period in cycle 1 and in regularly irrigated seedlings in both cycles. However, no differential responses due to inoculation were observed. The mycorrhizal colonisation of the seedlings at the end of the experiment was related with the initial colonisation level. Mycorrhizal colonisation by R. roseolus in old roots was maintained at significantly higher levels in seedlings which had an initial colonisation level >50% than in seedlings with 50% than in seedlings with an initial colonisation sensors can be used to detect a differential response of plants according to water supply, mycorrhizal status and, in some cases, to their colonisation level. The results are discussed in relation to the predictive possibilities of the method for the selection of efficient mycorrhizal fungi for the promotion of plant growth.

  13. Adult trees cause density-dependent mortality in conspecific seedlings by regulating the frequency of pathogenic soil fungi.

    Science.gov (United States)

    Liang, Minxia; Liu, Xubing; Gilbert, Gregory S; Zheng, Yi; Luo, Shan; Huang, Fengmin; Yu, Shixiao

    2016-12-01

    Negative density-dependent seedling mortality has been widely detected in tropical, subtropical and temperate forests, with soil pathogens as a major driver. Here we investigated how host density affects the composition of soil pathogen communities and consequently influences the strength of plant-soil feedbacks. In field censuses of six 1-ha permanent plots, we found that survival was much lower for newly germinated seedlings that were surrounded by more conspecific adults. The relative abundance of pathogenic fungi in soil increased with increasing conspecific tree density for five of nine tree species; more soil pathogens accumulated around roots where adult tree density was higher, and this greater pathogen frequency was associated with lower seedling survival. Our findings show how tree density influences populations of soil pathogens, which creates plant-soil feedbacks that contribute to community-level and population-level compensatory trends in seedling survival. © 2016 John Wiley & Sons Ltd/CNRS.

  14. Towards plant wires.

    Science.gov (United States)

    Adamatzky, Andrew

    2014-08-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self-growing wetware circuits and devices, and integration of plant-based electronic components into future and emergent bio-hybrid systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  15. Effect of long-term drought on carbon allocation and nitrogen uptake of Pinus sylvestris seedlings

    Science.gov (United States)

    Pumpanen, Jukka; Aaltonen, Heidi; Lindén, Aki; Köster, Kajar; Biasi, Christina; Heinonsalo, Jussi

    2015-04-01

    Weather extremes such as drought events are expected to increase in the future as a result of climate change. The drought affects the allocation of carbon assimilated by plants e.g. by modifying the root to shoot ratio, amount of fine roots and the amount of mycorrhizal fungal hyphae. We studied the effect of long term drought on the allocation of carbon in a common garden experiment with 4-year-old Pinus sylvestris seedlings. Half of the seedlings were exposed to long-term drought by setting the soil water content close to wilting point for over two growing seasons whereas the other half was grown in soil close to field capacity. We conducted a pulse labelling with 13CO2 in the end of the study by injecting a known amount of 13C enriched CO2 to the seedlings and measuring the CO2 uptake and distribution of 13C to the biomass of the seedlings and to the root and rhizosphere respiration. In addition, we studied the effect of drought on the decomposition of needle litter and uptake of nitrogen by 15N labelled needles buried in the soil in litter bags. The litterbags were collected and harvested in the end of the experiment and the changes in microbial community in the litterbags were studied from the phospholipid fatty acid (PLFA) composition. We also determined the 15N isotope concentrations from the needles of the seedlings to study the effect of drought on the nitrogen uptake of the seedlings. Our results indicate that the drought had a significant effect both on the biomass allocation of the seedlings and on the microbial species composition. The amount of carbon allocated belowground was much higher in the seedlings exposed to drought compared to the control seedlings. The seedlings seemed to adapt their carbon allocation to long-term drought to sustain adequate needle biomass and water uptake. The seedlings also adapted their osmotic potential and photosynthesis capacity to sustain the long-term drought as was indicated by the measurements of osmotic potential

  16. Características biométricas de mudas de Tabebula chrysotricha(standl. formadas em diferentes substratos e soluções de fertirrigação, quando plantadas em campo Biometric characterizations of Tabebula chrysotricha (standl. seedlings formed in different substrates and fertirrigation solutions, when planted in fields

    Directory of Open Access Journals (Sweden)

    Isabele Sarzi

    2010-04-01

    solutions with electric conductivities of 1.06 dS m-1, 2.12 dS m-1, 3.2 dS m-1 and 4.25 dS m-1. The propagative material was sowed directly into plastic containers (120mL with the respective substrates. The fertilization was received through sub irrigation once a week, respecting the treatments of fertilizations. When the seedlings reached 20cm of height, approximately, they were replaced under black screens (9% of shading, where they remained until planting in Taubaté-SP. Seedlings produced in coconut fiber 100% granulate reached, in the field, higher heights, stem diameters and number of leaves. In function of applied solutions, heights of the aerial part were homogeneous starting from 167 days after planting. The production of T. chrysotricha seedlings is recommended in granulated coconut fiber substrate and fertilizer solutions with electric conductivity of 1.06 dS m-1.

  17. Pyridine 2,4-dicarboxylic acid suppresses tomato seedling growth

    Science.gov (United States)

    Fragkostefanakis, Sotirios; Kaloudas, Dimitrios; Kalaitzis, Panagiotis

    2018-01-01

    Pyridine 2,4-dicarboxylic acid is a structural analogue of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μΜ of PDCA decreased hydroxyproline content in roots while only the 250 μΜ treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μΜ PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs) are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μΜ which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analogue. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  18. Pyridine 2,4-Dicarboxylic Acid Suppresses Tomato Seedling Growth

    Directory of Open Access Journals (Sweden)

    Sotirios Fragkostefanakis

    2018-01-01

    Full Text Available Pyridine 2,4-dicarboxylic acid is a structural analog of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μM of PDCA decreased hydroxyproline content in roots while only the 250 μM treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μM PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μM which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analog. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  19. Insight into the hydraulics and resilience of Ponderosa pine seedlings using a mechanistic ecohydrologic model

    Science.gov (United States)

    Maneta, M. P.; Simeone, C.; Dobrowski, S.; Holden, Z.; Sapes, G.; Sala, A.; Begueria, S.

    2017-12-01

    In semiarid regions, drought-induced seedling mortality is considered to be caused by failure in the tree hydraulic column. Understanding the mechanisms that cause hydraulic failure and death in seedlings is important, among other things, to diagnose where some tree species may fail to regenerate, triggering demographic imbalances in the forest that could result in climate-driven shifts of tree species. Ponderosa pine is a common lower tree line species in the western US. Seedlings of ponderosa pine are often subject to low soil water potentials, which require lower water potentials in the xylem and leaves to maintain the negative pressure gradient that drives water upward. The resilience of the hydraulic column to hydraulic tension is species dependent, but from greenhouse experiments, we have identified general tension thresholds beyond which loss of xylem conductivity becomes critical, and mortality in Ponderosa pine seedlings start to occur. We describe this hydraulic behavior of plants using a mechanistic soil-vegetation-atmosphere transfer model. Before we use this models to understand water-stress induced seedling mortality at the landscape scale, we perform a modeling analysis of the dynamics of soil moisture, transpiration, leaf water potential and loss of plant water conductivity using detailed data from our green house experiments. The analysis is done using a spatially distributed model that simulates water fluxes, energy exchanges and water potentials in the soil-vegetation-atmosphere continuum. Plant hydraulic and physiological parameters of this model were calibrated using Monte Carlo methods against information on soil moisture, soil hydraulic potential, transpiration, leaf water potential and percent loss of conductivity in the xylem. This analysis permits us to construct a full portrait of the parameter space for Ponderosa pine seedling and generate posterior predictive distributions of tree response to understand the sensitivity of transpiration

  20. Responses of Tree Seedlings near the Alpine Treeline to Delayed Snowmelt and Reduced Sky Exposure

    Directory of Open Access Journals (Sweden)

    Maaike Y. Bader

    2017-12-01

    Full Text Available Earlier snowmelt changes spring stress exposure and growing-season length, possibly causing shifts in plant species dominance. If such shifts involve trees, this may lead to changes in treeline position. We hypothesized that earlier snowmelt would negatively affect the performance of tree seedlings near the treeline due to higher spring stress levels, but less so if seedlings were protected from the main stress factors of night frosts and excess solar radiation. We exposed seedlings of five European treeline tree species: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata, and Sorbus aucuparia to two snow-cover treatments (early and late melting, with about two weeks difference combined with reduced sky exposure during the day (shading or night (night warming, repeated in two years, at a site about 200 m below the regional treeline elevation. Physiological stress levels (as indicated by lower Fv/Fm in the first weeks after emergence from snow were higher in early-emerging seedlings. As expected, shade reduced stress, but contrary to expectation, night warming did not. However, early- and late-emerging seedlings did not differ overall in their growth or survival, and the interaction with shading was inconsistent between years. Overall, shading had the strongest effect, decreasing stress levels and mortality (in the early-emerging seedlings only, but also growth. A two-week difference in snow-cover duration did not strongly affect the seedlings, although even smaller differences have been shown to affect productivity in alpine and arctic tundra vegetation. Still, snowmelt timing cannot be discarded as important for regeneration in subalpine conditions, because (1 it is likely more critical in very snow-rich or snow-poor mountains or landscape positions; and (2 it can change (subalpine vegetation phenology and productivity, thereby affecting plant interactions, an aspect that should be considered in future studies.

  1. PERCHLORATE PHYTOREMEDIATION USING HARDWOOD TREES AND VASCULAR PLANTS

    Science.gov (United States)

    Perchlorate has contaminated water and soils at several locations in the United States. Perchlorate iswater soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground and surface water conditions. Perchlorate is of concern because of...

  2. Effects of light intensity and fertilization on the growth of Andean Oak Seedlings at Nursery

    International Nuclear Information System (INIS)

    Sepulveda, Yira Lucia; Diez, Maria Claudia; Moreno, Flavio Humberto; Leon, Juan Diego; Walter Osorio, Nelson

    2014-01-01

    Quercus humboldtii is a native plant species of great importance in Colombia for use in reforestation and restoration of degraded Andean highlands. The species is highly threatened and it is necessary to establish programs of propagation and planting. However, little is known about their nutritional and light requirements. The aim of this study was to determine the effects of single and combined relative illumination (IR) and fertilization on the growth of seedlings of Q. humboldtii at nursery. For this purpose three contrasting ir regimes (high, medium, and low ir) and nine fertilization treatments were established: complete (TC), a missing nutrient (-N,-P,-K,-Ca,-Mg, -S,-B) and a control without fertilization (TO). The best development of seedlings was showed in the medium ir condition. All treatments with a lacking nutrient showed decreases in seedling development regarding TC, except in the -B treatment. Nitrogen was the most limiting nutrient yielding biomass similar to that of TO. The impact of nutrient limitation on seedling performance was in the following order:-N>-Ca,-K,-P>-Mg,-S>-B. no significant interaction IR x fertilization was detected on seedling development.

  3. Warming and neighbor removal affect white spruce seedling growth differently above and below treeline.

    Science.gov (United States)

    Okano, Kyoko; Bret-Harte, M Syndonia

    2015-01-01

    Climate change is expected to be pronounced towards higher latitudes and altitudes. Warming triggers treeline and vegetation shifts, which may aggravate interspecific competition and affect biodiversity. This research tested the effects of a warming climate, habitat type, and neighboring plant competition on the establishment and growth of white spruce (Picea glauca (Moench) Voss) seedlings in a subarctic mountain region. P. glauca seedlings were planted in June 2010 under 4 different treatments (high/control temperatures, with/without competition) in 3 habitats (alpine ridge above treeline/tundra near treeline /forest below treeline habitats). After two growing seasons in 2011, growth, photosynthesis and foliar C and N data were obtained from a total of 156, one-and-a-half year old seedlings that had survived. Elevated temperatures increased growth and photosynthetic rates above and near treeline, but decreased them below treeline. Competition was increased by elevated temperatures in all habitat types. Our results suggest that increasing temperatures will have positive effects on the growth of P. glauca seedlings at the locations where P. glauca is expected to expand its habitat, but increasing temperatures may have negative effects on seedlings growing in mature forests. Due to interspecific competition, possibly belowground competition, the upslope expansion of treelines may not be as fast in the future as it was the last fifty years.

  4. Fate of 14C-labelled diazinon in rice seedling and paddy soil

    International Nuclear Information System (INIS)

    Lee, Seong Kye; Kim, Kyoon; Park, Chang Kyu; Hwang, Eul Chul

    1985-01-01

    The fate of diazinon in the intact rice plants and submerged paddy soil has been investigated with (2- 14 C pyrimidine) diazinon. The labelled diazinon solution was applied to paddy water and distribution of radioactivities in the rice seedlings, paddy soil, volatile fraction and carbon dioxide has been ascertained at end the of incubation times of 0.5,1,4,6 and 9 days respectively. In addition, extract of plants and paddy soils were subjected to TLC separation for examination of possible transformation products of diazinon. The results may be summarized as follow; 1. Total recoveries of radiactivities were between 57.2∼73.6 per cent. 2. Radioactivity in rice seedlings increased with incubation periods reaching one tenth of treated radioactivity at the end of 9 day incubation. 3. Non-extractable radioactivity in paddy soil increased with incubation periods. 4. Radioactive volatile fraction increased in the presence of the rice seedlings. 5. Pyrimidinol was unique conversion product of diazinon in rice seedlings and paddy soils. 6. Pyrimidinol applied to paddy soil is readily absorbed by rice seedlings. (Author)

  5. Effects of rhizobacteria on the respiration and growth of Cerasus sachalinensis Kom. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Qin, S.; Zhou, W.; Li, Z.; Lyu, D.

    2016-11-01

    In this study, we investigated the influence of rhizosphere microorganisms on seed germination and root metabolism in Cerasus sachalinensis Kom. We inoculated C. sachalinensis plants with suspensions of dominant bacterial strains isolated from their rhizosphere. Four bacterial strains each with significant growth-promoting or growth-inhibiting effects were screened from the efficient root-colonizing microorganisms. The number of actinomycetes increased and that of fungi decreased significantly in the seedling rhizospheres after rhizobacteria treatment. The growth-promoting bacteria slightly affected the respiration rates and respiratory pathway enzymes, but significantly improved root viability, root carbohydrate concentration and seedling growth. Bacillus cereus, Staphylococcus sp. and Pseudomonas fluorescens were identified as the growth-promoting rhizobacteria; one strain could not be identified. After inoculation with the growth-inhibiting bacteria, the number of fungal colonies in the seedling rhizospheres increased and root viability and respiration rate as well as starch and sucrose accumulation in the roots significantly decreased. The glycolysis, pentose phosphate and alternative oxidase pathways became the major pathways of respiratory metabolism after inoculation with the growth-inhibiting bacteria. The height, leaf number, growth and dry weight of the seedlings decreased significantly in plants inoculated with the growth-inhibiting bacteria. Inoculation of C. sachalinensis rhizosphere with growth-promoting and growth-inhibiting bacteria affected the soil environmental factors such as microbial group composition, nutrient concentration and seedling biomass. (Author)

  6. Germination and development of pecan cultivar seedlings by seed stratification

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate the effect of seed stratification on germination rate, germination speed, and initial development of seedlings of six pecan (Carya illinoinensis cultivars under subtropical climatic conditions in southern Brazil. For stratification, the seeds were placed in boxes with moist sand, in a cold chamber at 4°C, for 90 days. In the fourteenth week after sowing, the emergence speed index, total emergence, plant height, stem diameter, and number of leaves were evaluated. Seed stratification significantly improves the germination potential and morphological traits of the evaluated cultivars.

  7. Synthesis of Pisolithus Ectomycorrhizae on Pecan Seedlings in Fumigated Soil

    Science.gov (United States)

    Donald H. Marx

    1979-01-01

    Curtis variety of pecan (Carya illinoensis) seedlings were grown for 8 months in fumigated soil infested at sowing with mycelial inoculum of Pisolithus tinctorius. Pisolithus ectomycorrhizae were formed on all inoculated seedlings and significantly improved their growth over control seedlings. Inoculated and control seedlings also formed ectomycorrhizae with naturally...

  8. Seed and seedling traits affecting critical life stage transitions and recruitment outcomes in dryland grasses

    Science.gov (United States)

    1. Seeding native plants is a key management practice to counter land degradation across the globe, yet the majority of seeding efforts fail, limiting the ability of this tool to accelerate ecosystem recovery. 2. Seedling recruitment requires transitions through several life stages, some of which ma...

  9. Overstory removal and residue treatments affect soil surface, air, and soil temperature: implications for seedling survival

    Science.gov (United States)

    Roger D. Hungerford; Ronald E. Babbitt

    1987-01-01

    Potentially lethal ground surface temperatures were measured at three locations in the Northern Rocky Mountains but occurred more frequently under treatments with greater overstory removal. Observed maximum and minimum temperatures of exposed surfaces are directly related to the thermal properties of the surface materials. Survival of planted seedlings was consistent...

  10. Exogenous abscisic acid application during grain filling in winter wheat improves cold tolerance of offspring's seedlings

    DEFF Research Database (Denmark)

    Li, X.; Cai, J.; Liu, Fulai

    2014-01-01

    Low temperature seriously depresses seed germination and seedling growth in winter wheat (Triticum aestivum L.). In this study, wheat plants were sprayed with abscisic acid (ABA) and fluridone (inhibitor of ABA biosynthesis) at 19 days after anthesis (DAA) and repeated at 26 DAA. The seeds of those...

  11. β-Amino-n-butyric Acid Regulates Seedling Growth and Disease Resistance of Kimchi Cabbage

    Directory of Open Access Journals (Sweden)

    Yeong Chae Kim

    2013-09-01

    Full Text Available Non-protein amino acid, β-amino-n-butyric acid (BABA, has been involved in diverse physiological processes including seedling growth, stress tolerance and disease resistance of many plant species. In the current study, treatment of kimchi cabbage seedlings with BABA significantly reduced primary root elongation and cotyledon development in a dose-dependent manner, which adverse effects were similar to the plant response to exogenous abscisic acid (ABA application. BABA was synergistically contributing ABA-induced growth arrest during the early seedling development. Kimchi cabbage leaves were highly damaged and seedling growth was delayed by foliar spraying with high concentrations of BABA (10 to 20 mM. BABA played roles differentially in in vitro fungal conidial germination, mycelial growth and conidation of necrotroph Alternaria brassicicola causing black spot disease and hemibiotroph Colletotrichum higginsianum causing anthracnose. Pretreatment with BABA conferred induced resistance of the kimchi cabbage against challenges by the two different classes of fungal pathogens in a dose-dependent manner. These results suggest that BABA is involved in plant development, fungal development as well as induced fungal disease resistance of kimchi cabbage plant.

  12. Growth, Plastochron, and the Final Number of Nodes of China Pink Seedlings Grown on Different Substrates

    Directory of Open Access Journals (Sweden)

    Marília Milani

    Full Text Available ABSTRACT The objective of this work was to plot the growth curves and determine the plastochron and the final number of nodes of China pink seedlings grown on different substrates. Thus, 392 China pink seedlings were grown on seven substrates under greenhouse conditions, in Santa Maria in the state of Rio Grande do Sul, Brazil. The growth curves were plotted using the logistic model. The plastochron was estimated by the inverse of the angular coefficient of the simple linear regression between the number of accumulated nodes and accumulated thermal sum from the subsampling of the seedlings. In all substrates, the logistic model fit better for the variable number of leaves than for the plant height. The plants in substrates with 50% of soil plus 50% of rice husk ash, and 80% of rice husk ash plus 20% earthworm humus had the longest cycles with 74 and 65 days, respectively. They completed the cycles with a thermal sum of 1317.9 ºC day for number of leaves and plant height. The growth curves that were plotted by the logistic model and the plastochron of the China pink seedlings are dependent on the type of substrate used. The commercial substrate Mecplant® had the best results. The average final number of nodes of the main stem of the plants was 14 for all substrates.

  13. Seasonal dynamics of ectomycorrhizal fungus assemblages on oak seedlings in the southeastern Appalachian Mountains

    Science.gov (United States)

    John F. Walker; Orson K. Jr. Miller; Jonathan L. Horton

    2008-01-01

    The potential for seasonal dynamics in ectomycorrhizal (EM) fungal assemblages has important implications for the ecology of both the host trees and the fungal associates. We compared EM fungus distributions on root systems of out-planted oak seedlings at two sites in mixed southeastern Appalachian Mountain forests at the Coweeta Hydrologic Laboratory in North Carolina...

  14. Tree Seedlings Establishment Across a Hydrologic Gradient in a Bottomland Restoration

    Science.gov (United States)

    Randall K. Kolka; Carl C. Trettin; E.A. Nelson; W.H. Conner

    1998-01-01

    Seedling establishment and survival on the Savannah River Site in South Carolina is being monitored as part of the Pen Branch Bottomland Restoration Project. Bottomland tree species were planted from 1993-1995 across a hydrologic gradient which encompasses the drier upper floodplain corridor, the lower floodplain corridor and the continuously inundated delta. Twelve...

  15. Induction of resistance in cucumber against seedling damping-off by ...

    African Journals Online (AJOL)

    Bacillus megaterium L8, a plant growth-promoting rhizobacterium (PGPR), was isolated and evaluated for its ability to induce resistance in cucumber against seedling damping-off caused by Pythium aphanidermatum. Root-splitting challenge experiments showed that L8 treatment of cucumber roots more effectively ...

  16. Stocktype and vegetative competition influences on Pseudotsuga menziesii and Larix occidentalis seedling establishment

    Science.gov (United States)

    Jeremiah R. Pinto; Bridget A. McNassar; Olga A. Kildisheva; Anthony S. Davis

    2018-01-01

    Douglas fir (Pseudotsuga menziesii var. glauca (Mayr) Franco), and western larch (Larix occidentalis Nutt.) are species of ecological and commercial importance that occur throughout the Western United States. Effective reforestation of these species relies on successful seedling establishment, which is affected by planting stock quality, stocktype size, and...

  17. Effects of temperature on Pinus patula seedlings growing in pots in a ...

    African Journals Online (AJOL)

    The re-establishment of Pinus patula seedlings into sites with high harvesting residue (slash) loads can negatively affect the survival of these plants. Field trials have examined the role that insect pests and fungal diseases play in causing this phenomenon. Research has also indicated that temperatures at ground level tend ...

  18. HISTONE DEACETYLASE 9 represses seedling traits in Arabidopsis thaliana dry seeds

    NARCIS (Netherlands)

    van Zanten, Martijn; Zöll, C.; Wang, Z.; Philipp, C.; Carles, A.; Li, Y.; Kornet, N.G.; Liu, Y.; Soppe, W.J.J.

    2014-01-01

    Plant life is characterized by major phase changes. We studied the role of histone deacetylase (HDAC) activity in the transition from seed to seedling in Arabidopsis. Pharmacological inhibition of HDAC stimulated germination of freshly harvested seeds. Subsequent analysis revealed that histone

  19. [Adaptability of Helianthus annuus seedlings to crude oil pollution in soil and its improvement measures under salinization stress].

    Science.gov (United States)

    Zhang, Jing-lei; Ci, Hua-cong; He, Xing-dong; Liang, Yu-ting; Zhao, Xuan; Sun, Hui-ting; Xie, Hong-tao

    2015-11-01

    To explore the adaptability of plant under salt stress to crude oil pollution of soil and improvement measures, a pot experiment of Helianthus annuus seedlings was conducted using orthogonal experiment method with crude oil-sodium chloride-desulfurization gypsum and cinder-zeolite-desulfurization gypsum-sawdust. The results showed that, with the increase of soil crude oil concentration, the relative growth rate (RGR) of plant height, RGR of aboveground biomass and root N: P ratios of H. annuus seedlings decreased significantly, while the activity of SOD and CAT increased at first and then decreased significantly. The RGR of plant height and aboveground biomass significantly increased (P pollution of soil could decrease the relative growth rate of H. annuus seedling, and sawdust could reduce the influence of crude oil pollution on plant growth under salt stress.

  20. Effect of elevated Al and pH on the growth and root morphology of Al-tolerant and Al-sensitive wheat seedlings in an acid soil

    Directory of Open Access Journals (Sweden)

    Md. Toufiq Iqbal

    2014-03-01

    Full Text Available Aluminium ion (Al3+ toxicity and hydrogen ion (H+ activity are the major constraints for plant growth in acid soil. This study was undertaken to determine the effect of pH and Al on the growth response and changes in root morphology of Al-tolerant (ET8 and Al-sensitive (ES8 wheat seedlings. Different levels of AlCl3 and CaCO3 were added to the soils to manipulate soil pH and extractable Al. The results showed that the bulk soil pH remained constant at pH 4.1 with further applications of AlCl3, and that the seedlings died at the 200 mg AlCl3/kg treatments. The ET8 seedlings responded better than the ES8 seedlings in both low and high Al and pH. The ET8 seedlings had higher root surface areas and root tip numbers than the ES8 seedlings in the Al treatment. In contrast, the ES8 had higher root diameters than the ET8 seedlings due to the elevated Al supply. Apoplast Al increased with the increase of soil available extractable Al, and declined with the decrease of soil extractable Al. The ET8 seedlings accumulated more Al in their apoplast than the ES8 seedlings. This study concluded that accumulation of Al in the apoplast is also involved in Al tolerance mechanism with the addition of organic acid exudation.