WorldWideScience

Sample records for extinct seed plants

  1. Seed planting

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes prairie seed plantings on Neal Smith National Wildlife Refuge (formerly Walnut Creek National Wildlife Refuge) between 1992 and 2009.

  2. Seed dispersal anachronisms: rethinking the fruits extinct megafauna ate.

    Directory of Open Access Journals (Sweden)

    Paulo R Guimarães

    Full Text Available BACKGROUND: Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals > 10(3 kg, yet these dispersers were extinct in South America 10-15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. METHODOLOGY/PRINCIPAL FINDINGS: We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4-10 cm in diameter with up to five large seeds, and fruits > 10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size with either a single or few ( 100 seeds. Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. CONCLUSIONS/SIGNIFICANCE: Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal by relying on frugivores able to disperse enormous seed loads over long-distances. Present-day seed dispersal by scatter-hoarding rodents, introduced livestock, runoff, flooding, gravity, and human-mediated dispersal allowed survival of megafauna-dependent fruit species after extinction of the major seed dispersers. Megafauna extinction had several potential consequences, such as a scale shift reducing the seed dispersal distances, increasingly clumped spatial patterns, reduced geographic ranges and limited genetic variation and increased among

  3. High loss of plant phylogenetic and functional diversity due to simulated extinctions of pollinators and seed dispersers in a tropical savanna

    OpenAIRE

    Cianciaruso, Marcus V.; Batalha,Marco Antônio; Petchey, Owen L.

    2013-01-01

    Identification of the factors driving extinctions is fundamental to conservation biology. Here, we assessed the likely consequences of extinction of pollinators and dispersers for phylogenetic and functional diversity of savanna woody plant species. Loss of phylogenetic diversity was greater than expected by chance in simulated extinctions of moth- and beetle-pollinated species, and bird- and mammal-dispersed species. In extinction simulations of bee and bat-pollinated species, the loss of fu...

  4. Reconstructing past ecological networks: the reconfiguration of seed-dispersal interactions after megafaunal extinction.

    Science.gov (United States)

    Pires, Mathias M; Galetti, Mauro; Donatti, Camila I; Pizo, Marco A; Dirzo, Rodolfo; Guimarães, Paulo R

    2014-08-01

    The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as seed dispersal. The traits of several species of large-seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in seed-dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich seed-dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the seed-dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how seed dispersers were distributed among network modules. However, the recent introduction of livestock into the seed-dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the seed-dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.

  5. Plant evolution: pulses of extinction and speciation in gymnosperm diversity.

    Science.gov (United States)

    Davis, Charles C; Schaefer, Hanno

    2011-12-20

    Living gymnosperms represent the survivors of ancient seed plant lineages whose fossil record reaches back 270 million years. Two recent studies find that recent pulses of extinction and speciation have shaped today's gymnosperm diversity, contradicting the widespread assumption that gymnosperms have remained largely unchanged for tens of millions of years.

  6. [Silphium from Cyrenaica, an extinct medicinal plant].

    Science.gov (United States)

    Haas, Charles

    2008-01-01

    Silphium was both a spice and a medicinal plant. It was regarded as "one of the most precious gifts of Nature to man" (Pliny), and was one of the main sources of revenue contributing to Cyrenaica's wealth. It was so critical to the Cyrenian economy that most of their coins bore a picture of the plant. But, by the time of Nero, the plant had become extinct, probably as a result of overgrazing and overcropping. The botanical identification of silphium is dificult, but the plant was an Umbellifera and most closely resembled Ferula tingitana. Hippocrates, Celsus, Galen and Oribasius recommended it for quartan fever, but it was also said to be useful for many other diseases.

  7. Prescribed seed plantings

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains memos, notes, and tables related to tallgrass prairie seed harvesting on Neal Smith National Wildlife Refuge in 1995.

  8. Atmospheric extinction in simulation tools for solar tower plants

    Science.gov (United States)

    Hanrieder, Natalie; Wilbert, Stefan; Schroedter-Homscheidt, Marion; Schnell, Franziska; Guevara, Diana Mancera; Buck, Reiner; Giuliano, Stefano; Pitz-Paal, Robert

    2017-06-01

    Atmospheric extinction causes significant radiation losses between the heliostat field and the receiver in a solar tower plants. These losses vary with site and time. State of the art is that in ray-tracing and plant optimization tools, atmospheric extinction is included by choosing between few constant standard atmospheric conditions. Even though some tools allow the consideration of site and time dependent extinction data, such data sets are nearly never available. This paper summarizes and compares the most common model equations implemented in several ray-tracing tools. There are already several methods developed and published to measure extinction on-site. An overview of the existing methods is also given here. Ray-tracing simulations of one exemplary tower plant at the Plataforma Solar de Almería (PSA) are presented to estimate the plant yield deviations between simulations using standard model equations instead of extinction time series. For PSA, the effect of atmospheric extinction accounts for losses between 1.6 and 7 %. This range is caused by considering overload dumping or not. Applying standard clear or hazy model equations instead of extinction time series lead to an underestimation of the annual plant yield at PSA. The discussion of the effect of extinction in tower plants has to include overload dumping. Situations in which overload dumping occurs are mostly connected to high radiation levels and low atmospheric extinction. Therefore it can be recommended that project developers should consider site and time dependent extinction data especially on hazy sites. A reduced uncertainty of the plant yield prediction can significantly reduce costs due to smaller risk margins for financing and EPCs. The generation of extinction data for several locations in form of representative yearly time series or geographical maps should be further elaborated.

  9. Cascading effects of bird functional extinction reduce pollination and plant density.

    Science.gov (United States)

    Anderson, Sandra H; Kelly, Dave; Ladley, Jenny J; Molloy, Sue; Terry, Jon

    2011-02-25

    Reductions in bird numbers could hamper ecosystem services such as pollination, but experimental proof is lacking. We show that functional extinction of bird pollinators has reduced pollination, seed production, and plant density in the shrub Rhabdothamnus solandri (Gesneriaceae) on the North Island ("mainland") of New Zealand but not on three nearby island bird sanctuaries where birds remain abundant. Pollen limitation of fruit set is strong [pollen limitation index (PLI) = 0.69] and significant on the mainland but small (PLI = 0.15) and nonsignificant on islands. Seed production per flower on the mainland is reduced 84%. Mainland sites have similar adult densities, but 55% fewer juvenile plants per adult, than island sites. Seed addition experiments near adult R. solandri plants on the mainland found strong seed limitation 5 years after sowing for R. solandri but not for two other co-occurring woody species. This demonstrates a terrestrial trophic cascade.

  10. The evolution of seed dormancy: environmental cues, evolutionary hubs, and diversification of the seed plants.

    Science.gov (United States)

    Willis, Charles G; Baskin, Carol C; Baskin, Jerry M; Auld, Josh R; Venable, D Lawrence; Cavender-Bares, Jeannine; Donohue, Kathleen; Rubio de Casas, Rafael

    2014-07-01

    Seed dormancy, by controlling the timing of germination, can strongly affect plant survival. The kind of seed dormancy, therefore, can influence both population and species-level processes such as colonization, adaptation, speciation, and extinction. We used a dataset comprising over 14,000 taxa in 318 families across the seed plants to test hypotheses on the evolution of different kinds of seed dormancy and their association with lineage diversification. We found morphophysiological dormancy to be the most likely ancestral state of seed plants, suggesting that physiologically regulated dormancy in response to environmental cues was present at the origin of seed plants. Additionally, we found that physiological dormancy (PD), once disassociated from morphological dormancy, acted as an 'evolutionary hub' from which other dormancy classes evolved, and that it was associated with higher rates of lineage diversification via higher speciation rates. The environmental sensitivity provided by dormancy in general, and by PD in particular, appears to be a key trait in the diversification of seed plants. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  11. Ecological networks are more sensitive to plant than to animal extinction under climate change

    Science.gov (United States)

    Schleuning, Matthias; Fründ, Jochen; Schweiger, Oliver; Welk, Erik; Albrecht, Jörg; Albrecht, Matthias; Beil, Marion; Benadi, Gita; Blüthgen, Nico; Bruelheide, Helge; Böhning-Gaese, Katrin; Dehling, D. Matthias; Dormann, Carsten F.; Exeler, Nina; Farwig, Nina; Harpke, Alexander; Hickler, Thomas; Kratochwil, Anselm; Kuhlmann, Michael; Kühn, Ingolf; Michez, Denis; Mudri-Stojnić, Sonja; Plein, Michaela; Rasmont, Pierre; Schwabe, Angelika; Settele, Josef; Vujić, Ante; Weiner, Christiane N.; Wiemers, Martin; Hof, Christian

    2016-01-01

    Impacts of climate change on individual species are increasingly well documented, but we lack understanding of how these effects propagate through ecological communities. Here we combine species distribution models with ecological network analyses to test potential impacts of climate change on >700 plant and animal species in pollination and seed-dispersal networks from central Europe. We discover that animal species that interact with a low diversity of plant species have narrow climatic niches and are most vulnerable to climate change. In contrast, biotic specialization of plants is not related to climatic niche breadth and vulnerability. A simulation model incorporating different scenarios of species coextinction and capacities for partner switches shows that projected plant extinctions under climate change are more likely to trigger animal coextinctions than vice versa. This result demonstrates that impacts of climate change on biodiversity can be amplified via extinction cascades from plants to animals in ecological networks. PMID:28008919

  12. Alien plant invasions and native plant extinctions: a six-threshold framework

    Science.gov (United States)

    Downey, Paul O.; Richardson, David M.

    2016-01-01

    Biological invasions are widely acknowledged as a major threat to global biodiversity. Species from all major taxonomic groups have become invasive. The range of impacts of invasive taxa and the overall magnitude of the threat is increasing. Plants comprise the biggest and best-studied group of invasive species. There is a growing debate; however, regarding the nature of the alien plant threat—in particular whether the outcome is likely to be the widespread extinction of native plant species. The debate has raised questions on whether the threat posed by invasive plants to native plants has been overstated. We provide a conceptual framework to guide discussion on this topic, in which the threat posed by invasive plants is considered in the context of a progression from no impact through to extinction. We define six thresholds along the ‘extinction trajectory’, global extinction being the final threshold. Although there are no documented examples of either ‘in the wild’ (Threshold 5) or global extinctions (Threshold 6) of native plants that are attributable solely to plant invasions, there is evidence that native plants have crossed or breached other thresholds along the extinction trajectory due to the impacts associated with plant invasions. Several factors may be masking where native species are on the trajectory; these include a lack of appropriate data to accurately map the position of species on the trajectory, the timeframe required to definitively state that extinctions have occurred and management interventions. Such interventions, focussing mainly on Thresholds 1–3 (a declining population through to the local extinction of a population), are likely to alter the extinction trajectory of some species. The critical issue for conservation managers is the trend, because interventions must be implemented before extinctions occur. Thus the lack of evidence for extinctions attributable to plant invasions does not mean we should disregard the broader

  13. Seed bank characteristics of Dutch plant communities

    NARCIS (Netherlands)

    Bekker, RM; Schaminee, JHJ; Bakker, JP; Thompson, K

    With the recent appearances of a new and well-documented classification of the Dutch plant communities (Schaminee et al 1995a,b; 1996) and a database on the seed longevity of plant species of North West Europe (Thompson ct al. 1997a) it was possible to investigate patterns of seed longevity in Dutch

  14. Seed bank characteristics of Dutch plant communities

    NARCIS (Netherlands)

    Bekker, RM; Schaminee, JHJ; Bakker, JP; Thompson, K

    1998-01-01

    With the recent appearances of a new and well-documented classification of the Dutch plant communities (Schaminee et al 1995a,b; 1996) and a database on the seed longevity of plant species of North West Europe (Thompson ct al. 1997a) it was possible to investigate patterns of seed longevity in Dutch

  15. Ants sow the seeds of global diversification in flowering plants.

    Science.gov (United States)

    Lengyel, Szabolcs; Gove, Aaron D; Latimer, Andrew M; Majer, Jonathan D; Dunn, Robert R

    2009-01-01

    The extraordinary diversification of angiosperm plants in the Cretaceous and Tertiary periods has produced an estimated 250,000-300,000 living angiosperm species and has fundamentally altered terrestrial ecosystems. Interactions with animals as pollinators or seed dispersers have long been suspected as drivers of angiosperm diversification, yet empirical examples remain sparse or inconclusive. Seed dispersal by ants (myrmecochory) may drive diversification as it can reduce extinction by providing selective advantages to plants and can increase speciation by enhancing geographical isolation by extremely limited dispersal distances. Using the most comprehensive sister-group comparison to date, we tested the hypothesis that myrmecochory leads to higher diversification rates in angiosperm plants. As predicted, diversification rates were substantially higher in ant-dispersed plants than in their non-myrmecochorous relatives. Data from 101 angiosperm lineages in 241 genera from all continents except Antarctica revealed that ant-dispersed lineages contained on average more than twice as many species as did their non-myrmecochorous sister groups. Contrasts in species diversity between sister groups demonstrated that diversification rates did not depend on seed dispersal mode in the sister group and were higher in myrmecochorous lineages in most biogeographic regions. Myrmecochory, which has evolved independently at least 100 times in angiosperms and is estimated to be present in at least 77 families and 11 000 species, is a key evolutionary innovation and a globally important driver of plant diversity. Myrmecochory provides the best example to date for a consistent effect of any mutualism on large-scale diversification.

  16. Measurement of solar extinction in tower plants with digital cameras

    Science.gov (United States)

    Ballestrín, J.; Monterreal, R.; Carra, M. E.; Fernandez-Reche, J.; Barbero, J.; Marzo, A.

    2016-05-01

    Atmospheric extinction of solar radiation between the heliostat field and the receiver is accepted as a non-negligible source of energy loss in the increasingly large central receiver plants. However, the reality is that there is currently no reliable measurement method for this quantity and at present these plants are designed, built and operated without knowing this local parameter. Nowadays digital cameras are used in many scientific applications for their ability to convert available light into digital images. Its broad spectral range, high resolution and high signal to noise ratio, make them an interesting device in solar technology. In this work a method for atmospheric extinction measurement based on digital images is presented. The possibility of defining a measurement setup in circumstances similar to those of a tower plant increases the credibility of the method. This procedure is currently being implemented at Plataforma Solar de Almería.

  17. The role of climatic tolerances and seed traits in reduced extinction rates of temperate polygonaceae.

    Science.gov (United States)

    Kostikova, Anna; Salamin, Nicolas; Pearman, Peter B

    2014-07-01

    The latitudinal diversity gradient (LDG) is one of the most striking and consistent biodiversity patterns across taxonomic groups. We investigate the species richness gradient in the buckwheat family, Polygonaceae, which exhibits a reverse LDG and is, thus, decoupled from dominant gradients of energy and environmental stability that increase toward the tropics and confound mechanistic interpretations. We test competing age and evolutionary diversification hypotheses, which may explain the diversification of this plant family over the past 70 million years. Our analyses show that the age hypothesis, which posits that clade richness is positively correlated with the ecological and evolutionary time since clade origin, fails to explain the richness gradient observed in Polygonaceae. However, an evolutionary diversification hypothesis is highly supported, with diversification rates being 3.5 times higher in temperate clades compared to tropical clades. We demonstrate that differences in rates of speciation, migration, and molecular evolution insufficiently explain the observed patterns of differential diversification rates. We suggest that reduced extinction rates in temperate clades may be associated with adaptive responses to selection, through which seed morphology and climatic tolerances potentially act to minimize risk in temporally variable environments. Further study is needed to understand causal pathways among these traits and factors correlated with latitude. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  18. Pollen and seed dispersal among dispersed plants.

    Science.gov (United States)

    Ghazoul, Jaboury

    2005-08-01

    The ecological significance of spacing among plants in contributing to the maintenance of species richness, particularly in tropical forests, has received considerable attention that has largely focussed on distance- and density-dependent seed and seedling mortality. More recently it has become apparent that plant spacing is also relevant to pollination, which often constrains seed production. While seed and seedling survival is reduced at high conspecific densities, pollination success, by contrast, is positively correlated to local conspecific density. Distance-dependent mechanisms acting on pollination and seed production have now been described for a variety of plants, with relatively isolated plants or fragmented populations generally suffering reduced fecundity due to pollen limitation. Yet there is considerable variability in the vulnerability of plant species to pollination failure, which may be a function of breeding system, life history, the pollination vector, the degree of specialisation among plants and their pollinators, and other indirect effects of habitat change acting on plants or pollinators. As reduced tree densities and population fragmentation are common outcomes of anthropogenically altered landscapes, understanding how pollination processes are affected in such degraded landscapes can inform effective conservation and management of remaining natural areas.

  19. Endangered plant-parrot mutualisms: seed tolerance to predation makes parrots pervasive dispersers of the Parana pine

    Science.gov (United States)

    Tella, José L.; Dénes, Francisco V.; Zulian, Viviane; Prestes, Nêmora P.; Martínez, Jaime; Blanco, Guillermo; Hiraldo, Fernando

    2016-01-01

    Parrots are largely considered plant antagonists as they usually destroy the seeds they feed on. However, there is evidence that parrots may also act as seed dispersers. We evaluated the dual role of parrots as predators and dispersers of the Critically Endangered Parana pine (Araucaria angustifolia). Eight of nine parrot species predated seeds from 48% of 526 Parana pines surveyed. Observations of the commonest parrot indicated that 22.5% of the picked seeds were dispersed by carrying them in their beaks. Another five parrot species dispersed seeds, at an estimated average distance of c. 250 m. Dispersal distances did not differ from those observed in jays, considered the main avian dispersers. Contrary to jays, parrots often dropped partially eaten seeds. Most of these seeds were handled by parrots, and the proportion of partially eaten seeds that germinated was higher than that of undamaged seeds. This may be explained by a predator satiation effect, suggesting that the large seeds of the Parana pine evolved to attract consumers for dispersal. This represents a thus far overlooked key plant-parrot mutualism, in which both components are threatened with extinction. The interaction is becoming locally extinct long before the global extinction of the species involved. PMID:27546381

  20. Does adaptive strategy for delayed seed dispersion affect extinction probability of a desert species? an assessment using the population viability analysis and glass house experiment

    Directory of Open Access Journals (Sweden)

    Manish Mathur

    2014-10-01

    Full Text Available Canopy seed bank is an important adaptive evolutionary trait that provides various types of protection to the seeds. However, costing of such evolutionary trait on plant survival is largely unknown. Present investigation provided a new insight on the serotonious habit of Blepharis sindica associated with its endangerment status. Extinction probabilities of two available population of B. sindica were quantified using two types of census data, i.e., fruiting body number and actual population size. Population Viability Analysis (PVA revealed that delayed seed release tendency (higher fruiting body number was not synchronized with actual ground conditions (lower population size. PVA analysis based on actual population size indicated that both the available populations would vanish within 20 years. The mean time of extinction calculated from both type census data indicated its extinction within 48 years. For assessing the conservation criteria, a glass house experiment was carried out with different soil types and compositions. Pure sand and higher proportions of sand -silt were more suitable compared to clay; further, gravelly surface was the most unsuitable habitat for this species. Collection of the seeds from mature fruits/capsule and their sowing with moderate moisture availability with sandy soil could be recommended.

  1. Extinction cascades partially estimate herbivore losses in a complete Lepidoptera--plant food web.

    Science.gov (United States)

    Pearse, Ian S; Altermatt, Florian

    2013-08-01

    The loss of species from an ecological community can have cascading effects leading to the extinction of other species. Specialist herbivores are highly diverse and may be particularly susceptible to extinction due to host plant loss. We used a bipartite food web of 900 Lepidoptera (butterfly and moth) herbivores and 2403 plant species from Central Europe to simulate the cascading effect of plant extinctions on Lepidoptera extinctions. Realistic extinction sequences of plants, incorporating red-list status, range size, and native status, altered subsequent Lepidoptera extinctions. We compared simulated Lepidoptera extinctions to the number of actual regional Lepidoptera extinctions and found that all predicted scenarios underestimated total observed extinctions but accurately predicted observed extinctions attributed to host loss (n = 8, 14%). Likely, many regional Lepidoptera extinctions occurred for reasons other than loss of host plant alone, such as climate change and habitat loss. Ecological networks can be useful in assessing a component of extinction risk to herbivores based on host loss, but further factors may be equally important.

  2. Ancestral polyploidy in seed plants and angiosperms.

    Science.gov (United States)

    Jiao, Yuannian; Wickett, Norman J; Ayyampalayam, Saravanaraj; Chanderbali, André S; Landherr, Lena; Ralph, Paula E; Tomsho, Lynn P; Hu, Yi; Liang, Haiying; Soltis, Pamela S; Soltis, Douglas E; Clifton, Sandra W; Schlarbaum, Scott E; Schuster, Stephan C; Ma, Hong; Leebens-Mack, Jim; dePamphilis, Claude W

    2011-05-05

    Whole-genome duplication (WGD), or polyploidy, followed by gene loss and diploidization has long been recognized as an important evolutionary force in animals, fungi and other organisms, especially plants. The success of angiosperms has been attributed, in part, to innovations associated with gene or whole-genome duplications, but evidence for proposed ancient genome duplications pre-dating the divergence of monocots and eudicots remains equivocal in analyses of conserved gene order. Here we use comprehensive phylogenomic analyses of sequenced plant genomes and more than 12.6 million new expressed-sequence-tag sequences from phylogenetically pivotal lineages to elucidate two groups of ancient gene duplications-one in the common ancestor of extant seed plants and the other in the common ancestor of extant angiosperms. Gene duplication events were intensely concentrated around 319 and 192 million years ago, implicating two WGDs in ancestral lineages shortly before the diversification of extant seed plants and extant angiosperms, respectively. Significantly, these ancestral WGDs resulted in the diversification of regulatory genes important to seed and flower development, suggesting that they were involved in major innovations that ultimately contributed to the rise and eventual dominance of seed plants and angiosperms. ©2011 Macmillan Publishers Limited. All rights reserved

  3. The effect of shock loading on the survival of plant seeds

    Science.gov (United States)

    Leighs, J. A.; Hazell, P. J.; Appleby-Thomas, G. J.

    2012-07-01

    Meteorite and asteroid impacts into planet Earth seem rare but over the lifetime of our planet have been relatively frequent. Such collisions (involving very large impactors) have been blamed for mass extinctions during Earth’s history. It has also been postulated that impactors could carry life with them throughout the universe and seed our planet. This is the basis of the theory of panspermia (‘life everywhere’) and suggests that life could be spread throughout the universe by ‘piggy-backing’ on inter-planetary bodies, e.g. asteroids, which then collide with other planets, thus seeding them with life. The shock behaviour of organic matter has an important role to play in helping to inform the feasibility of such theories. An example of a model carrier for life in seeding mechanisms is the plant seed. Here we present the development of an experimental technique in which plant seed samples are shock-loaded and their viability subsequently assessed post-shock. This technique was tested on Lepidium sativum (cress) seed samples. Experimentally, shocked seeds showed positive viability in all tests performed until shocked with a maximum peak shock pressure of ca. 0.8 GPa. These results suggest it is unlikely that the plant seeds tested would be able to survive the extreme conditions on an asteroid during impact, but may be able to survive shock waves that would be generated from such collisions when existing on a planetary body.

  4. Seed rain and seed bank reveal that seed limitation strongly influences plant community assembly in grasslands.

    Directory of Open Access Journals (Sweden)

    Bryndís Marteinsdóttir

    Full Text Available Dispersal is an important factor in plant community assembly, but assembly studies seldom include information on actual dispersal into communities, i.e. the local propagule pool. The aim of this study was to determine which factors influence plant community assembly by focusing on two phases of the assembly process: the dispersal phase and the establishment phase. At 12 study sites in grazed ex-arable fields in Sweden the local plant community was determined and in a 100-m radius around the centre of each site, the regional species pool was measured. The local seed bank and the seed rain was explored to estimate the local propagule pool. Trait-based models were then applied to investigate if species traits (height, seed mass, clonal abilities, specific leaf area and dispersal method and regional abundance influenced which species from the regional species pool, dispersed to the local community (dispersal phase and which established (establishment phase. Filtering of species during the dispersal phase indicates the effect of seed limitation while filtering during the establishment phase indicates microsite limitation. On average 36% of the regional species pool dispersed to the local sites and of those 78% did establish. Species with enhanced dispersal abilities, e.g. higher regional abundance, smaller seeds and dispersed by cattle, were more likely to disperse to the sites than other species. At half the sites, dispersal was influenced by species height. Species establishment was however mainly unlinked to the traits included in this study. This study underlines the importance of seed limitation in local plant community assembly. It also suggests that without information on species dispersal into a site, it is difficult to distinguish between the influence of dispersal and establishment abilities, and thus seed and microsite limitation, as both can be linked to the same trait.

  5. Book Review on the Illustrated Seeds of Chinese Medicinal Plants

    Institute of Scientific and Technical Information of China (English)

    Guo QS; Wang QY; Liu L; HE Shan-an

    2010-01-01

    @@ Medicinal plants are important source for Oriental and Western medicines. There are more than 500 herbs commonly used today in China, in which near 30% of them are seed medicines and over 65% are propagated from seed.

  6. Seed fate in the myrmecochorous Neotropical plant Turnera ulmifolia L., from plant to germination

    Science.gov (United States)

    Salazar-Rojas, Betzabeth; Rico-Gray, Víctor; Canto, Azucena; Cuautle, Mariana

    2012-04-01

    Myrmecochory (seed dispersal by ants) differs from other dispersal systems in a series of advantages offered by the ants to the plants. Here, seed fate, from fruit to germination, of the myrmecochorous Neotropical plant Turnera ulmifolia L. is described. Seed movement from the fruit to their germination was studied, using different measurements and experiments. The results show that a T. ulmifolia individual produces ca. 5000 seeds per year. The main pre-seed-fall predators are the larvae of the Microlepidopteran Crocidosema plebejana Zeller, which consumed 1% of the seeds on the plant. The red-land crab Gecarcinus lateralis (Freminville) consumed 19% of the seeds beneath the plant and was the main post-seed-fall predator. Seed removal by ants was recorded on and beneath the plant, and ants removed 49% of the total seed production. Considering the seed removal events, the ant Forelius analis contributed with 64% of the total number of events. F. analis took seeds to its nest and discarded 23% of the seeds collected. Germination of seeds collected by F. analis was two to four times higher than that of seeds with and without elaiosome, respectively. The relatively low seed predation was probably related to ant defense, associated with the presence of extrafloral nectaries in this plant and with seed removal on the plant. Our results suggest that F. analis is a quantitatively efficient but qualitatively inefficient seed disperser of T. ulmifolia.

  7. Assessing ant seed predation in threatened plants: a case study

    Science.gov (United States)

    Albert, María José; Escudero, Adrián; Iriondo, José María

    2005-11-01

    Erodium paularense is a threatened plant species that is subject to seed predation by the granivorous ant Messor capitatus. In this paper we assessed the intensity and pattern of ant seed predation and looked for possible adaptive strategies at the seed and plant levels to cope with this predation. Seed predation was estimated in 1997 and 1998 at the population level by comparing total seed production and ant consumption, assessed by counting seed hulls in refuse piles. According to this method, ant seed predation ranged between 18% and 28%. A more detailed and direct assessment conducted in 1997 raised this estimate to 43%. In this assessment spatial and temporal patterns of seed predation by ants were studied by mapping all nest entrances in the studied area and marking the mature fruits of 109 reproductive plants with a specific colour code throughout the seed dispersal period. Intact fruit coats were later recovered from the refuse piles, and their mother plants and time of dispersal were identified. Seeds dispersed at the end of the dispersal period had a greater probability of escaping from ant seed predation. Similarly, in plants with late dispersal a greater percentage of seeds escaped from ant predation. Optimum dispersal time coincided with the maximum activity of granivorous ants because, at this time, ants focused their harvest on other plant species of the community. It was also observed that within-individual seed dispersal asynchrony minimised seed predation. From a conservation perspective, results show that the granivorous ant-plant interaction cannot be assessed in isolation and that the intensity of its effects basically depends on the seed dispersal pattern of the other members of the plant community. Furthermore, this threat must be assessed by considering the overall situation of the target population. Thus, in E. paularense, the strong limitation of safe-sites for seedling establishment reduces the importance of seed predation.

  8. Onion seed vigor in relation to plant growth and yield

    OpenAIRE

    Rodo Angélica B.; Marcos-Filho Julio

    2003-01-01

    Research has emphasized the relationship of laboratory germination and vigor to seedling emergence and stand establishment, but information relating seed vigor to plant performance is less available. The reliable procedures to evaluate onion (Allium cepa L.) seed vigor and decided the differences between seed physiological potential influence plant performance in field conditions were identified in two experimental years. Six seed lots of Petroline cultivar were evaluated for germination and ...

  9. Effect of Hydropriming and Biopriming on Seed Germination and Growth of Two Mexican Fir Tree Species in Danger of Extinction

    Directory of Open Access Journals (Sweden)

    Ramón Zulueta-Rodríguez

    2015-09-01

    Full Text Available Abies spp. in general have been shown to need a period of cold stratification to break dormancy and germinate, but this can be very time consuming. In this study, hydropriming by itself and in combination with biopriming was carried out on Abies hickelii and Abies religiosa seeds. For biopriming, three species of plant growth promoting rhizobacteria ( Pseudomonas fluorescens, P. putida and Bacillus subtilis were tested. The purpose was to determine if germination and growth could be improved for these two endangered species. Our results demonstrated that treating A. hickelii and A. religiosa with both hydropriming and biopriming with certain strains of Plant Growth-Promoting Rhizobacteria (PGPR could improve germination rates up to 91% for A. hickelii and up to 68% for A. religiosa. Importantly, these treatments showed no significant negative impact on the growth of A. religiosa and actually improved growth in A. hickelii. The application of both hydropriming and biopriming offer possibly an alternative methodology to improve germination, survival and preservation of these fir tree species of Mexico that are at risk of extinction.

  10. Plant response to sunflower seeds to osmotic conditioning

    Directory of Open Access Journals (Sweden)

    Camila Santos Barros de Morais

    2014-10-01

    Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.

  11. Extinction risk and diversification are linked in a plant biodiversity hotspot.

    Science.gov (United States)

    Davies, T Jonathan; Smith, Gideon F; Bellstedt, Dirk U; Boatwright, James S; Bytebier, Benny; Cowling, Richard M; Forest, Félix; Harmon, Luke J; Muasya, A Muthama; Schrire, Brian D; Steenkamp, Yolande; van der Bank, Michelle; Savolainen, Vincent

    2011-05-01

    It is widely recognized that we are entering an extinction event on a scale approaching the mass extinctions seen in the fossil record. Present-day rates of extinction are estimated to be several orders of magnitude greater than background rates and are projected to increase further if current trends continue. In vertebrates, species traits, such as body size, fecundity, and geographic range, are important predictors of vulnerability. Although plants are the basis for life on Earth, our knowledge of plant extinctions and vulnerabilities is lagging. Here, we disentangle the underlying drivers of extinction risk in plants, focusing on the Cape of South Africa, a global biodiversity hotspot. By comparing Red List data for the British and South African floras, we demonstrate that the taxonomic distribution of extinction risk differs significantly between regions, inconsistent with a simple, trait-based model of extinction. Using a comprehensive phylogenetic tree for the Cape, we reveal a phylogenetic signal in the distribution of plant extinction risks but show that the most threatened species cluster within short branches at the tips of the phylogeny--opposite to trends in mammals. From analyzing the distribution of threatened species across 11 exemplar clades, we suggest that mode of speciation best explains the unusual phylogenetic structure of extinction risks in plants of the Cape. Our results demonstrate that explanations for elevated extinction risk in plants of the Cape flora differ dramatically from those recognized for vertebrates. In the Cape, extinction risk is higher for young and fast-evolving plant lineages and cannot be explained by correlations with simple biological traits. Critically, we find that the most vulnerable plant species are nonetheless marching towards extinction at a more rapid pace but, surprisingly, independently from anthropogenic effects. Our results have important implications for conservation priorities and cast doubts on the

  12. Extinction risk and diversification are linked in a plant biodiversity hotspot.

    Directory of Open Access Journals (Sweden)

    T Jonathan Davies

    2011-05-01

    Full Text Available It is widely recognized that we are entering an extinction event on a scale approaching the mass extinctions seen in the fossil record. Present-day rates of extinction are estimated to be several orders of magnitude greater than background rates and are projected to increase further if current trends continue. In vertebrates, species traits, such as body size, fecundity, and geographic range, are important predictors of vulnerability. Although plants are the basis for life on Earth, our knowledge of plant extinctions and vulnerabilities is lagging. Here, we disentangle the underlying drivers of extinction risk in plants, focusing on the Cape of South Africa, a global biodiversity hotspot. By comparing Red List data for the British and South African floras, we demonstrate that the taxonomic distribution of extinction risk differs significantly between regions, inconsistent with a simple, trait-based model of extinction. Using a comprehensive phylogenetic tree for the Cape, we reveal a phylogenetic signal in the distribution of plant extinction risks but show that the most threatened species cluster within short branches at the tips of the phylogeny--opposite to trends in mammals. From analyzing the distribution of threatened species across 11 exemplar clades, we suggest that mode of speciation best explains the unusual phylogenetic structure of extinction risks in plants of the Cape. Our results demonstrate that explanations for elevated extinction risk in plants of the Cape flora differ dramatically from those recognized for vertebrates. In the Cape, extinction risk is higher for young and fast-evolving plant lineages and cannot be explained by correlations with simple biological traits. Critically, we find that the most vulnerable plant species are nonetheless marching towards extinction at a more rapid pace but, surprisingly, independently from anthropogenic effects. Our results have important implications for conservation priorities and cast

  13. Seed ferns survived the end-Cretaceous mass extinction in Tasmania.

    Science.gov (United States)

    McLoughlin, Stephen; Carpenter, Raymond J; Jordan, Gregory J; Hill, Robert S

    2008-04-01

    Seed ferns, dominant elements of the vegetation in many parts of the world from the Triassic to Cretaceous, were considered to have disappeared at the end of the Cretaceous together with several other groups that had occupied key positions in terrestrial and marine ecosystems such as dinosaurs, plesiosaurs, and ammonoids. Seed-fern demise is generally correlated with competition from diversifying flowering plants through the Cretaceous and the global environmental crisis related to the Chicxulub impact event in the paleotropics at the end of the period. New fossils from Tasmania show that one seed-fern lineage survived into the Cenozoic by at least 13 million years. These fossils are described here as a new species, Komlopteris cenozoicus. Komlopteris is a genus of seed ferns attributed to Corystospermaceae and until now was not known from sediments younger than the Early Cretaceous. Discovery of this "Lazarus taxon," together with the presence of a range of other relictual fossil and extant organisms in Tasmania, other southern Gondwanan provinces, and some regions of northern North America and Asia, underscores high-latitude regions as biodiversity refugia during global environmental crises and highlights their importance as sources of postextinction radiations.

  14. Can fruit seeds and undigested plant residuals cause acute appendicitis

    Directory of Open Access Journals (Sweden)

    Omer Engin

    2011-04-01

    Conclusions: The ratio of acute appendicitis caused by plants is minimal among all appendectomised patients, but avoidence of eating undigested fruit seeds and chewing plants well may help to prevent appendicitis.

  15. Effect of planting dates on seed yield and seed quality of Stylosanthes guianensis CIAT 184

    Directory of Open Access Journals (Sweden)

    Chureerat Satjipanon

    2005-11-01

    Full Text Available The objective of this experiment was to investigate the effect of planting dates on seed yield and quality of Stylosanthes guianensis CIAT 184 at Khon Kaen Animal Nutrition Research and Development Center, during May 2003 to February 2004. A randomized complete block design with four replications was used. Experimental treatments consisted of four planting dates spaced at about 30-day intervals from 23 May to 23 August 2003.The results revealed that planting date had a significant effect on seed yields and pure germinable seed yields (PGSY of S. guianensis CIAT 184. Plots planted on 23 July produced the highest seed yield and PGSY of 630 and 601 kg/ha, respectively followed by plots planted on 23 June and 23 May (514 and 501; 443 and 421 kg/ha, respectively. Plots planted on 23 August produced the lowest seed yield and PGSY of 269 and 262 kg/ha, respectively. There were no significant differences in seed purity percentage, germination percentage and 1000-seed weight among planting dates. Based on this research, it was concluded that late- July was the optimum planting date for S. guianensis CIAT 184 cultivation for seed production in Northeast Thailand.

  16. Mitochondrial biogenesis in plants during seed germination.

    Science.gov (United States)

    Law, Simon R; Narsai, Reena; Whelan, James

    2014-11-01

    Mitochondria occupy a central role in the eukaryotic cell. In addition to being major sources of cellular energy, mitochondria are also involved in a diverse range of functions including signalling, the synthesis of many essential organic compounds and a role in programmed cell death. The active proliferation and differentiation of mitochondria is termed mitochondrial biogenesis and necessitates the coordinated communication of mitochondrial status within an integrated cellular network. Two models of mitochondrial biogenesis have been defined previously, the growth and division model and the maturation model. The former describes the growth and division of pre-existing mature organelles through a form of binary fission, while the latter describes the propagation of mitochondria from structurally and biochemically simple promitochondrial structures that upon appropriate stimuli, mature into fully functional mitochondria. In the last decade, a number of studies have utilised seed germination in plants as a platform for the examination of the processes occurring during mitochondrial biogenesis. These studies have revealed many new aspects of the tightly regulated procession of events that define mitochondrial biogenesis during this period of rapid development. A model for mitochondrial biogenesis that supports the maturation of mitochondria from promitochondrial structures has emerged, where mitochondrial signalling plays a crucial role in the early steps of seed germination.

  17. In vivo nuclear magnetic resonance metabolite profiling in plant seeds.

    Science.gov (United States)

    Terskikh, Victor; Kermode, Allison R

    2011-01-01

    Nuclear magnetic resonance (NMR) spectroscopy has been successfully applied to profile a variety of primary and secondary metabolites in whole intact plant seeds in vivo. The nondestructive nature of NMR spectroscopy allows direct metabolic studies to be performed on the same seed throughout a given physio-logical process or key lifecycle transition, such as dormancy breakage, germination, and early postgerminative growth. Multinuclear NMR is capable of evaluating seed quality by assessing nondestructively nutrient reserves and seed protectants at seed maturity and to further monitor reserve mobilization following germination, which is critical for seedling emergence. In this chapter, we illustrate the use of several in vivo NMR techniques for metabolite profiling in seeds. Importantly, some of these methods have potential for the screening of single seeds or seed populations to identify seedlots with compromised viability either due to developmental problems or as a result of deterioration during prolonged storage.

  18. Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.

    Directory of Open Access Journals (Sweden)

    Xavier Arnan

    Full Text Available Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation and benefits (seed dispersal, the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.

  19. Uncoupling the effects of seed predation and seed dispersal by granivorous ants on plant population dynamics.

    Science.gov (United States)

    Arnan, Xavier; Molowny-Horas, Roberto; Rodrigo, Anselm; Retana, Javier

    2012-01-01

    Secondary seed dispersal is an important plant-animal interaction, which is central to understanding plant population and community dynamics. Very little information is still available on the effects of dispersal on plant demography and, particularly, for ant-seed dispersal interactions. As many other interactions, seed dispersal by animals involves costs (seed predation) and benefits (seed dispersal), the balance of which determines the outcome of the interaction. Separate quantification of each of them is essential in order to understand the effects of this interaction. To address this issue, we have successfully separated and analyzed the costs and benefits of seed dispersal by seed-harvesting ants on the plant population dynamics of three shrub species with different traits. To that aim a stochastic, spatially-explicit individually-based simulation model has been implemented based on actual data sets. The results from our simulation model agree with theoretical models of plant response dependent on seed dispersal, for one plant species, and ant-mediated seed predation, for another one. In these cases, model predictions were close to the observed values at field. Nonetheless, these ecological processes did not affect in anyway a third species, for which the model predictions were far from the observed values. This indicates that the balance between costs and benefits associated to secondary seed dispersal is clearly related to specific traits. This study is one of the first works that analyze tradeoffs of secondary seed dispersal on plant population dynamics, by disentangling the effects of related costs and benefits. We suggest analyzing the effects of interactions on population dynamics as opposed to merely analyzing the partners and their interaction strength.

  20. Can fruit seeds and undigested plant residuals cause acute appendicitis

    Institute of Scientific and Technical Information of China (English)

    Omer Engin; Mehmet Yildirim; Savas Yakan; Gulnihal Ay Coskun

    2011-01-01

    Objective:To investigate the relation between fruit seeds, plants residuals and appendicitis. Methods: Among cases that underwent appendectomy, the appendicitis cases having fruit seeds and undigested plant residuals in their etiology were examined retrospectively. Also, histopathological features, age, sex, and parameters of morbidity and mortality were used. Results: Fruit seed was found in one case(0.05%) with presence of pus in appendix lumen, undigested plant residuals in 7 cases(0.35%). It was determined that there were appendix inflammation in 2 of the plant residuals cases, while there were obstruction and lymphoid hyperplasia in the appendix lumen of5 cases. No mortality was observed.Conclusions: The ratio of acute appendicitis caused by plants is minimal among all appendectomised patients, but avoidence of eating undigested fruit seeds and chewing plants well may help to prevent appendicitis.

  1. Plant-seed predator interactions – ecological and evolutionary aspects

    OpenAIRE

    Östergård, Hannah

    2008-01-01

    Plant-animal interactions are affected by both abundance and distribution of interacting species and the community context in which they occur. However, the relative importance of these factors is poorly known. I examined the effects of predator host range, environmental factors, host plant populations, plant traits and fruit abortion on the intensity of pre-dispersal seed predation in 46 host populations of the perennial herb Lathyrus vernus. I recorded damage by beetle pre-dispersal seed pr...

  2. Assessment of Genetic Diversity in Seed Plants Based on a Uniform π Criterion

    Directory of Open Access Journals (Sweden)

    Bin Ai

    2014-12-01

    Full Text Available Despite substantial advances in genotyping techniques and massively accumulated data over the past half century, a uniform measurement of neutral genetic diversity derived by different molecular markers across a wide taxonomical range has not yet been formulated. We collected genetic diversity data on seed plants derived by AFLP, allozyme, ISSR, RAPD, SSR and nucleotide sequences, converted expected heterozygosity (He to nucleotide diversity (π, and reassessed the relationship between plant genetic diversity and life history traits or extinction risk. We successfully established a uniform π criterion and developed a comprehensive plant genetic diversity database. The mean population-level and species-level π values across seed plants were 0.00374 (966 taxa, 155 families, 47 orders and 0.00569 (728 taxa, 130 families, 46 orders, respectively. Significant differences were recovered for breeding system (p < 0.001 at the population level and geographic range (p = 0.023 at the species level. Selfing taxa had significantly lower π values than outcrossing and mixed-mating taxa, whereas narrowly distributed taxa had significantly lower π values than widely distributed taxa. Despite significant differences between the two extreme threat categories (critically endangered and least concern, the genetic diversity reduction on the way to extinction was difficult to detect in early stages.

  3. [Research advance in seed germination of desert woody plants].

    Science.gov (United States)

    Chang, Wei; Wu, Jian-guo; Liu, Yan-hong

    2007-02-01

    This paper reviewed the research methods of desert woody plants seed germination, and the effects of internal and external ecological factors on it. Most researchers use incubator and artificial climate chamber to dispose the seeds, while field investigation was few involved. Seed dormancy is the important physiological factor affecting germination, while seed size, mass and color are closely correlated with its maturity and vigor. The poor permeability of seed capsule is a barrier that restrains the germination, which can be weakened or eliminated by shaving, cutting, treating with low temperature, and dipping in chemical reagent, etc. Seed water content has a close correlation with its storage life and water-absorbing capability. Suitable temperature is the prerequisite of seed germination, while changing temperature can accelerate the germination. Soil moisture content is a limiting factor, while illumination is not so essential to the seed germination of most desert woody plants. Sand-burying plays an important role in the seed germination through regulating illumination, temperature, and soil moisture content. Salinity stress restrains the seed germination of desert woody plants observably. In further studies, the effects of multi-factors and the eco-physiological and molecular biological mechanisms of germination should be more concerned.

  4. ``From seed-to-seed'' experiment with wheat plants under space-flight conditions

    Science.gov (United States)

    Mashinsky, A.; Ivanova, I.; Derendyaeva, T.; Nechitailo, G.; Salisbury, F.

    1994-11-01

    An important goal with plant experiments in microgravity is to achieve a complete life cycle, the ``seed-to-seed experiment''. Some Soviet attempts to reach this goal are described, notably an experiment with the tiny mustard, Arabidopsis thaliana, in the Phyton 3 device on Salyut 7. Normal seeds were produced although yields were reduced and development was delayed. Several other experiments have shown abnormalities in plants grown in space. In recent work, plants of wheat (Triticum aestivum) were studied on the ground and then in a preliminary experiment in space. Biometric indices of vegetative space plants were 2 to 2.5 times lower than those of controls, levels of chlorophyll a and b were reduced (no change in the ratio of the two pigments), carotenoids were reduced, there was a serious imbalance in major minerals, and membrane lipids were reduced (no obvious change in lipid patterns). Following the preliminary studies, an attempt was made with the Svetoblock-M growth unit to grow a super-dwarf wheat cultivar through a life cycle. The experiment lasted 167 d on Mir. Growth halted from about day 40 to day 100, when new shoots appeared. Three heads had appeared in the boot (surrounded by leaves) when plants were returned to earth. One head was sterile, but 28 seeds matured on earth, and most of these have since produced normal plants and seeds. In principle, a seed-to-seed experiment with wheat should be successful in microgravity.

  5. "From seed-to-seed" experiment with wheat plants under space-flight conditions.

    Science.gov (United States)

    Mashinsky, A; Ivanova, I; Derendyaeva, T; Nechitailo, G; Salisbury, F

    1994-11-01

    An important goal with plant experiments in microgravity is to achieve a complete life cycle, the "seed-to-seed experiment." Some Soviet attempts to reach this goal are described, notably an experiment with the tiny mustard, Arabidopsis thaliana, in the Phyton 3 device on Salyut 7. Normal seeds were produced although yields were reduced and development was delayed. Several other experiments have shown abnormalities in plants grown in space. In recent work, plants of wheat (Triticum aestivum) were studied on the ground and then in a preliminary experiment in space. Biometric indices of vegetative space plants were 2 to 2.5 times lower than those of controls, levels of chlorophyll a and b were reduced (no change in the ratio of the two pigments), carotenoids were reduced, there was a serious imbalance in major minerals, and membrane lipids were reduced (no obvious change in lipid patterns). Following the preliminary studies, an attempt was made with the Svetoblock-M growth unit to grow a super-dwarf wheat cultivar through a life cycle. The experiment lasted 167 d on Mir. Growth halted from about day 40 to day 100, when new shoots appeared. Three heads had appeared in the boot (surrounded by leaves) when plants were returned to earth. One head was sterile, but 28 seeds matured on earth, and most of these have since produced normal plants and seeds. In principle, a seed-to-seed experiment with wheat should be successful in microgravity.

  6. Grazing impact on desert plants and soil seed banks: Implications for seed-eating animals

    Science.gov (United States)

    Pol, Rodrigo G.; Sagario, M. Cecilia; Marone, Luis

    2014-02-01

    We assess whether the knowledge of livestock diet helps to link grazing effects with changes in plant cover and soil seed bank size, aiming at inferring the consequences of grazing on seed-eating animals. Specifically, we test whether continuous and heavy grazing reduce the cover, number of reproductive structures and seed reserves of the same grass species whose seeds are selected and preferred by granivorous animals in the central Monte desert, Argentina. Grass cover and the number of grass spikes usually diminished under grazing conditions in the two localities studied (Telteca and Ñacuñán), and soil seed bank was consistently reduced in all three years evaluated owing to a decline of perennial grass and forb seeds. In particular, the abundance of those seeds selected and preferred by birds and ants (in all cases grass species) declined 70-92% in Ñacuñán, and 52-72% in Telteca. Reduction of perennial grass cover and spike number in grazed sites reinforced the causal link between livestock grazing and the decline of grass soil seed reserves throughout failed plant reproduction. Grass seed bank depletion suggests that grazing may trigger a "cascade" of mechanisms that affect the abundance and persistence of valuable fodder species as well as the availability of seed resources for granivorous animals.

  7. Seed dispersal of the Australian cycad Macrozamia miquelii (Zamiaceae): are cycads megafauna-dispersed "grove forming" plants?

    Science.gov (United States)

    Hall, John A; Walter, Gimme H

    2013-06-01

    Plants that invest in large, heavy seeds and colorful, fleshy fruits or analogous structures seem adapted for dispersal by large vertebrates. Some such plants, like Australian cycads in the genus Macrozamia, do not disperse well, which could be explained by seed-dispersal relationships with megafauna that are rare or extinct in contemporary ecosystems. Such plants provide an opportunity to investigate the ecological consequences of low seed-dispersal distances. • We investigated seed dispersal of Macrozamia miquelii in Central Queensland by tracking the fate of marked seeds, identifying the dispersal fauna and quantifying population demography and spatial structure. • We found that 70-100% of marked seeds remained within 1 m of maternal females (cycads are dioecious). Of the 812 seeds recovered (from 840 originally marked) only 24 dispersed >1 m from maternal females, the greatest observed dispersal being 5 m. We found an average of 2.2 seedlings and 0.7 juveniles within 1.5 m of mature females, which suggests that most seeds that remain in the vicinity of maternal females perish. Within-stand densities ranged between 1000 and 5000 plants/ha. The brushtail possum Trichosurus vulpecula was the only animal observed to move the seeds. • Macrozamia are adapted for dispersal by megafauna that are rare or absent in contemporary ecosystems. We argue that Macrozamia are "grove forming" plants that derive ecological benefit from existing as high-density, spatially discrete populations, the function of megafaunal dispersal adaptations being the infrequent dispersal of seeds en masse to establish new such groves in the landscape.

  8. Native Plants and Seeds, Oh My! Fifth Graders Explore an Unfamiliar Subject While Learning Plant Basics

    Science.gov (United States)

    Pauley, Lauren; Weege, Kendra; Koomen, Michele Hollingsworth

    2016-01-01

    Native plants are not typically the kinds of plants that are used in elementary classroom studies of plant biology. More commonly, students sprout beans or investigate with fast plants. At the time the authors started their plant unit (November), the school-yard garden had an abundance of native plants that had just started seeding, including…

  9. Endozoochorous dispersal of aquatic plants: does seed gut passage affect plant performance?

    Science.gov (United States)

    Figuerola, Jordi; Santamaría, Luis; Green, Andy J; Luque, Isabel; Alvarez, Raquel; Charalambidou, Iris

    2005-04-01

    The ingestion of seeds by vertebrates can affect the germinability and/or germination rate of seeds. It is, however, unclear if an earlier germination as a result of ingestion affects later plant performance. For sago pondweed, Potamogeton pectinatus, the effects of seed ingestion by ducks on both germinability and germination rate have been previously reported from laboratory experiments. We performed an experiment to determine the effects of seed ingestion by ducks on germination, seedling survival, plant growth and asexual multiplication. Both at the start and end of the winter, seeds were fed to three captive shovelers (Anas clypeata) and planted outdoors in water-filled containers. Plant biomass and its allocation to vegetative parts (shoot and roots), tubers, and seeds were determined in autumn. More duck-ingested seeds than control (uningested) seeds germinated in early winter, but this difference disappeared for seeds planted in late winter, when the treatments were first stratified for 3 mo. None of the variables for measuring seedling survival and plant performance varied between treatments. Under our experimental conditions (no herbivory or competition), ingestion by ducks in early winter resulted in increased performance for seeds surviving gut passage due to enhanced seed germinability, without other costs or benefits for the seedlings.

  10. Plant species with extremely small populations (PSESP in China: A seed and spore biology perspective

    Directory of Open Access Journals (Sweden)

    Ellie Merrett Wade

    2016-10-01

    Full Text Available Approximately one fifth of the world's plants are at risk of extinction. Of these, a significant number exist as populations of few individuals, with limited distribution ranges and under enormous pressure due to habitat destruction. In China, these most-at-risk species are described as ‘plant species with extremely small populations’ (PSESP. Implementing conservation action for such listed species is urgent. Storing seeds is one of the main means of ex situ conservation for flowering plants. Spore storage could provide a simple and economical method for fern ex situ conservation. Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation. But what is known about the seed and spore biology (storage and germination of at-risk species? We have used China's PSESP (the first group listing as a case study to understand the gaps in knowledge on propagule biology of threatened plant species. We found that whilst germination information is available for 28 species (23% of PSESP, storage characteristics are only known for 8% of PSESP (10 species. Moreover, we estimate that 60% of the listed species may require cryopreservation for long-term storage. We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.

  11. Endozoochorous dispersal of aquatic plants: does seed gut passage affect plant performance?

    NARCIS (Netherlands)

    Figuerola, J.; Santamaría, L.; Green, A.J.; Luque, I.; Alvarez, R.; Charalambidou, I.

    2005-01-01

    The ingestion of seeds by vertebrates can affect the germinability and/or germination rate of seeds. It is, however, unclear if an earlier germination as a result of ingestion affects later plant performance. For sago pondweed, Potamogeton pectinatus, the effects of seed ingestion by ducks on both g

  12. Rarity, species richness, and the threat of extinction--are plants the same as animals?

    Directory of Open Access Journals (Sweden)

    Sandra Knapp

    2011-05-01

    Full Text Available Assessment of conservation status is done both for areas or habitats and for species (or taxa. IUCN Red List categories have been the principal method of categorising species in terms of extinction risk, and have been shown to be robust and helpful in the groups for which they have been developed. A recent study highlights properties associated with extinction risk in flowering plants, focusing on the species-rich hot spot of the Cape region of South Africa, and concludes that merely following methods derived from studies of vertebrates may not provide the best estimates of extinction risk for plants. Biology, geography, and history all are important factors in risk, and the study poses many questions about how we categorise and assess species for conservation priorities.

  13. Features and distribution patterns of Chinese endemic seed plant species

    Institute of Scientific and Technical Information of China (English)

    Ji-Hong HUANG; Jian-Hua CHEN; Jun-Sheng YING; Ke-Ping MA

    2011-01-01

    We compiled and identified a list of Chinese. endemic seed plant species based on a large number of published References and expert reviews. The characters of these seed plant species and their distribution patterns were described at length. China is rich in endemic seed plants, with a total of 14 939 species (accounting for 52.1%of its total seed plant species) belonging to 1584 genera and 191 families. Temperate families and genera have a significantly higher proportion of endemism than cosmopolitan and tropical ones. The most primitive and derived groups have significantly higher endemism than the other groups. The endemism of tree, shrub, and liana or vine is higher than that of total species; in contrast, the endemism of herb is lower than that of total species. Geographically,these Chinese endemic plants are mainly distributed in Yunnan and Sichuan provinces, southwest China. Species richness and proportion of these endemic plants decrease with increased latitude and have a unimodal response to altitude. The peak value of proportion of endemism is at higher altitudes than that of total species and endemic species richness. The proportions of endemic shrub, liana or vine, and herb increase with altitude and have a clear unimodal curve. In contrast, the proportion of tree increases with altitude, with a sudden increase at~4000 m and has a completely different model. To date, our study provides the most comprehensive list of Chinese endemic seed plant species and their basic composition and distribution features.

  14. Early planting and hand sorting effectively controls seed-borne fungi in farm-retained bean seed

    Directory of Open Access Journals (Sweden)

    Ernest Dube

    2014-11-01

    Full Text Available Home-saved bean (Phaseolus vulgaris L. seed can be hand-sorted to remove discoloured seed, thereby reducing the level of contamination by certain seed-borne fungi and improving seed germination. In this study, the effect of planting date on the infection and discolouration of bean seed by seed-borne fungi was investigated in order to improve the quality of hand-sorted, farm-retained bean seeds used by resource poor smallholder farmers. The germination quality and level of seed-borne fungi in hand-sorted first-generation bean seed harvested from an early-, mid- and late-summer season planted crop was therefore assessed. The highest percentage of discoloured seed (68% was obtained from the mid-summer season planting. Non-discoloured seed from early- and late-season plantings had significantly (p"less than"0.001 higher normal germination (82% and 77%, respectively than that from the mid-season planting date (58%. Irrespective of planting date, unsorted seed and discoloured seed had higher levels of infection by Fusarium spp. and Phaeoisariopsis spp. than the non-discoloured seed. Removal of discoloured seed by hand sorting eliminated Rhizoctonia spp. from all seed lots. Farmers can eliminate this pathogen by simply removing discoloured seed. Non-discoloured seed from the early-planted crop had the lowest level of infection by Fusarium spp. and Phaeoisariopsis spp. The results indicate that planting date is an important consideration in improving the quality of hand-sorted farm-retained bean seed.

  15. Different tolerances of symbiotic and nonsymbiotic ant-plant networks to species extinctions

    Directory of Open Access Journals (Sweden)

    Wesley Dattilo

    2012-12-01

    Full Text Available The knowledge of the mechanisms that shape biodiversity-stability relationships is essential to understand ecological and evolutionary dynamics of interacting species. However, most studies focus only on species loss and ignore the loss of interactions. In this study, I evaluated the topological structure of two different ant-plant networks: symbiotic (ants and myrmecophytes and nonsymbiotic (ants and plants with extrafloral nectaries. Moreover, I also evaluated in both networks the tolerance to plant and ant species extinction using a new approach. For this, I used models based on simulations of cumulative removals of species from the network at random. Both networks were fundamentally different in the interaction and extinction patterns. The symbiotic network was more specialized and less robust to species extinction. On the other hand, the nonsymbiotic network tends to be functionally redundant and more robust to species extinction. The difference for food resource utilization and ant nesting in both ant-plant interactions can explain the observed pattern. In short, I contributed in this manner to our understanding of the biodiversity maintenance and coevolutionary processes in facultative and obligate mutualisms.

  16. an assessment of seed propagation of oilferous plant species with

    African Journals Online (AJOL)

    nb

    pedata grew luxuriously in all soil types while Jatropha curcas performed poorly ... recalcitrant and probably needed special attention and shortest storage time .... assess the effect of growth media on seed ..... Figure 4: Plant height of 4 plant species grown in 4 different soils 180 days .... utilize more light prior to leaf canopy.

  17. Age of planted Echinacea purpurea: The factor of seed yield and quality

    Directory of Open Access Journals (Sweden)

    Jevđović Radosav

    2007-01-01

    Full Text Available Results for yield and quality of echinacea purpurea seed obtained from age of plants one, two, three, four and five year are presented. In the laboratory experiments germination energy (GE, total germination (TG and weight seed was examined. The highest yield of seed was achieved in three-year echinacea purpurea plants, and the lowest yield was achieved in one-year plants. Age of planted established influence significant on total germination. This parametar the highest of seed in three-year plants and the lowest of seed in five-year echinacea purpurea plants. The highest of germination energy of seed established for the seed deriving from three-year echinacea purpurea planted, and the lowest in one-year plants. The absolute mass of seeds the highest in one-year plants, and the lowest for the seed deriving from five-year echinacea purpurea planted. .

  18. Impact of accelerated plant growth on seed variety development

    Science.gov (United States)

    Christophersen, Eric

    1998-01-01

    The commercial lives of agricultural seed products have steadily declined in recent years. The introduction of genetically engineered crop seeds in 1966 has accentuated that trend. Widespread grower demand for genetically engineered seed requires competitive response by industry followers in order to avert market share losses to the industry leaders. Limitations on plant transformation technology, regulatory requirements and patent impediments require companies to rapidly convert transformed lines into elite commercial products. Massive multigenerational backcrossing efforts are required to distribute genetically engineered traits into a broad product mix. Significant incidents of expression failures, or ``gene silencing,'' have occurred unexpectedly, requiring product substitution strategies. First-to-market strategies, competitive response, broad germplasm conversion and rescue of product failures all share the element of urgency. Technologies which reliably accelerate product development rates can expect favorable reception by commercial seed developers. A growth chamber which dramatically accelerates the rate of plant growth is described.

  19. Evolution of the YABBY gene family in seed plants.

    Science.gov (United States)

    Finet, Cédric; Floyd, Sandra K; Conway, Stephanie J; Zhong, Bojian; Scutt, Charles P; Bowman, John L

    2016-01-01

    Members of the YABBY gene family of transcription factors in angiosperms have been shown to be involved in the initiation of outgrowth of the lamina, the maintenance of polarity, and establishment of the leaf margin. Although most of the dorsal-ventral polarity genes in seed plants have homologs in non-spermatophyte lineages, the presence of YABBY genes is restricted to seed plants. To gain insight into the origin and diversification of this gene family, we reconstructed the evolutionary history of YABBY gene lineages in seed plants. Our findings suggest that either one or two YABBY genes were present in the last common ancestor of extant seed plants. We also examined the expression of YABBY genes in the gymnosperms Ephedra distachya (Gnetales), Ginkgo biloba (Ginkgoales), and Pseudotsuga menziesii (Coniferales). Our data indicate that some YABBY genes are expressed in a polar (abaxial) manner in leaves and female cones in gymnosperms. We propose that YABBY genes already acted as polarity genes in the last common ancestor of extant seed plants. © 2016 Wiley Periodicals, Inc.

  20. Effect of pre-planting irrigation, maize planting pattern and nitrogen on weed seed bank population.

    Science.gov (United States)

    Hemmati, E; Vazan, S; Oveisi, M

    2011-01-01

    Pre-planting irrigation and planting patterns are important factors in weed management that effect on seed bank. Additionally, the nitrogen is the most important factor in plant growth that affects weed-crop competition and ultimately, seed rain into the soil. A field experiment was conducted to study the effect of nitrogen application rates, pre-planting irrigation and maize planting patterns on weed seed bank population. Experimental factors were nitrogen rates at 4 levels (200, 300, 400 and 500 kg per hectare) as main plot; and pre-planting irrigation at 2 levels (irrigation before planting plus weeding emerged seedlings and, irrigation after sowing), and maize planting patterns (one-row and two-row planting of maize with same density per square of row length) that were assigned in a factorial arrangement to the sub plots. Soil samples were taken at the beginning of the season (before planting of maize) and at the end of the season (after harvest) at depth of 0-5 cm in the fixed quadrates (60 cm x 60 cm). The weed seeds were extracted from the soil samples and were identified using standard methods. The majority of weed seed bank populations included 6 weed species: Portulaca oleracea, Chenopodium album, Amaranthus retroflexus, Sorghum halepense, Daturea stramonium, Xanthium strumarium. Results showed that population of weed seed bank increased significantly with increasing nitrogen rate. The increasing rate was different between one-row and two-row planting patterns. The parameters indicated that seed bank population was much higher in a one row planting pattern of maize. With two-row planting, seed bank was decreased by 34, 26, 20 and 5% at 200, 300, 400 and 500 kg N/ha, respectively. Pre-planting irrigation was also found an effective implement to reduce the weed seed bank. When pre-planting irrigation was applied, seed bank was decreased by 57, 43, 34 and 9% at 200, 300, 400 and 500 kg N/ha. Increasing nitrogen because of weed's better growth and higher seed

  1. Molecular insights into seed dispersal mutualisms driving plant population recruitment

    Science.gov (United States)

    García, Cristina; Grivet, Delphine

    2011-11-01

    Most plant species require mutualistic interactions with animals to fulfil their demographic cycle. In this regard frugivory (i.e., the intake of fruits by animals) enhances natural regeneration by mobilizing a large amount of seeds from source trees to deposition sites across the landscape. By doing so, frugivores move propagules, and the genotypes they harbour creating the spatial, ecological, and genetic environment under which subsequent recruitment proceeds. Recruitment patterns can be envisioned as the result of two density- and distance-dependent processes: seed dispersal and seed/seedling survival (the Janzen-Connell model). Population genetic studies add another layer of complexity for understanding the fate of dispersed propagules: the genetic relatedness among neighbouring seeds within a seed clump, a major outcome of frugivore activity, modifies their chances of germinating and surviving. Yet, we virtually ignore how the spatial distribution of maternal progenies and recruitment patterns relate with each other in frugivore-generated seed rains. Here we focus on the critical role of frugivore-mediated seed dispersal in shaping the spatial distribution of maternal progenies in the seed rain. We first examine which genetic mechanisms underlying recruitment are influenced by the spatial distribution of maternal progenies. Next, we examine those studies depicting the spatial distribution of maternal progenies in a frugivore-generated seed rain. In doing so, we briefly review the most suitable analytical approaches applied to track the contribution of fruiting trees to the seed rain based on molecular data. Then we look more specifically at the role of distinct frugivore guilds in determining maternal genetic correlations and their expected consequences for recruitment patterns. Finally we posit some general conclusions and suggest future research directions that would provide a more comprehensive understanding of the ecological and evolutionary consequences

  2. Radiobiological experiments with plant seeds aboard the biosatellite Kosmos 1887

    Science.gov (United States)

    Anikeeva, I. D.; Vaulina, E. N.; Kostina, L. N.; Marenny, A. M.; Portman, A. I.; Rusin, S. V.; Benton, E. V.

    1990-01-01

    The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied provided with various protective measures: the seeds were located inside the satellite and in open space, protected with aluminium foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminium foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can be thus regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

  3. Radiobiological experiments with plant seeds aboard the biosatellite Cosmos 1887

    Science.gov (United States)

    Benton, E. V.; Anikeeva, I. D.; Akatov, Yu. A.; Vaulina, E. N.; Kostina, L. N.; Marenny, A.; Portman, A. I.; Rusin, S. V.

    1995-01-01

    The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied. The seeds were located inside the satellite in an open space, protected with aluminum foil and also exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminum foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival rate and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles (HCP). The seeds can thus be regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors.

  4. Geographic variations in seed dispersal by ants: are plant and seed traits decisive?

    Science.gov (United States)

    Boulay, R.; Coll-Toledano, J.; Manzaneda, A. J.; Cerdá, X.

    2007-03-01

    The effect of local ant species on the dispersal success of a myrmecochorous plant, Helleborus foetidus, was analyzed in two populations of the Iberian Peninsula (Caurel and Cazorla, respectively). The contribution of the various local ant species to dispersal was very unequal. While 5 and 19 ant taxa visited the plants of Caurel and Cazorla, respectively, most removal activity (67 and 80%) was performed by two species only (Formica lugubris and Camponotus cruentatus, respectively). Visits by dispersers were also unequally distributed between neighboring plants. While some plants were always visited during the period of seed release, others were never visited. A regression model indicated that this pattern might be explained by two plant traits: ants preferred to visit plants that released more seeds and whose elaiosomes were richer in oleic acid. Although it has long been known that this compound triggers removal by ants, it is the first demonstration that quantitative variations in elaiosome traits contribute to variation in dispersal success. Finally, other variables being equal, morphological traits (seed size, elaiosome size, and elaiosome/seed size ratio) did not affect ant behavior. Although myrmecochory has long been considered a diffuse interaction, our results support the idea that, at local scale, a limited number of ant species may be decisive to its evolution.

  5. Advances in seed conservation of wild plant species: a review of recent research

    National Research Council Canada - National Science Library

    Hay, Fiona R; Probert, Robin J

    2013-01-01

    .... Seed banking is now widely used for the ex situ conservation of wild plant species. Many seed banks that conserve wild species broadly follow international genebank guidelines for seed collection, processing, storage, and management...

  6. Scatter hoarding of seeds confers survival advantages and disadvantages to large-seeded tropical plants at different life stages.

    Directory of Open Access Journals (Sweden)

    Erin K Kuprewicz

    Full Text Available Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although

  7. Scatter hoarding of seeds confers survival advantages and disadvantages to large-seeded tropical plants at different life stages.

    Science.gov (United States)

    Kuprewicz, Erin K

    2015-01-01

    Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although tradeoffs in seed

  8. Modeling and analysis of a density-dependent stochastic integral projection model for a disturbance specialist plant and its seed bank.

    Science.gov (United States)

    Eager, Eric Alan; Rebarber, Richard; Tenhumberg, Brigitte

    2014-07-01

    In many plant species dormant seeds can persist in the soil for one to several years. The formation of these seed banks is especially important for disturbance specialist plants, as seeds of these species germinate only in disturbed soil. Seed movement caused by disturbances affects the survival and germination probability of seeds in the seed bank, which subsequently affect population dynamics. In this paper, we develop a stochastic integral projection model for a general disturbance specialist plant-seed bank population that takes into account both the frequency and intensity of random disturbances, as well as vertical seed movement and density-dependent seedling establishment. We show that the probability measures associated with the plant-seed bank population converge weakly to a unique measure, independent of initial population. We also show that the population either persists with probability one or goes extinct with probability one, and provides a sharp criteria for this dichotomy. We apply our results to an example motivated by wild sunflower (Helianthus annuus) populations, and explore how the presence or absence of a "storage effect" impacts how a population responds to different disturbance scenarios.

  9. Estimating seed production of common plants in seasonally flooded wetlands

    Science.gov (United States)

    Laubhan, Murray K.; Fredrickson, Leigh H.

    1992-01-01

    We developed a technique to quickly estimate seed production of common moist-soil plants because previously reported methods were too time consuming to be of value to waterfowl resource managers. Eleven regression equations were developed for 13 plant species in the upper Mississippi Alluvial Valley and the Rio Grande Valley, New Mexico. Estimated time to collect a sample was 1.5 minutes. Easily measured vegetation characteristics such as inflorescence number, inflorescence length, and plant height were used as independent variables to estimate seed mass of known mass samples. Coefficients of determination (R2) ranged from 0.79 for rice flatsedge (Cyperus iria) to 0.96 for smartweeds (Polygonum spp.). The accuracy and precision of equations tested using independent data indicate that the technique can be used to detect changes in seed mass of moist-soil plants in seasonally flooded impoundments. Because of the small sample area per plot used (0.0625 m2) and changes in the density of plants within an impoundment, we recommend that as many samples as economically feasible be collected to reliably estimate seed production.

  10. Tracing the primordial Chlamydiae: extinct parasites of plants?

    Science.gov (United States)

    Subtil, Agathe; Collingro, Astrid; Horn, Matthias

    2014-01-01

    Chlamydiae are obligate intracellular bacteria found as symbionts and pathogens in a wide range of eukaryotes, including protists, invertebrates, and vertebrates. It was recently proposed that an ancient chlamydial symbiont facilitated the establishment of primary plastids in a tripartite symbiosis with cyanobacteria and early eukaryotes. In this review, we summarize recent advances in understanding of the lifestyle and the evolutionary history of extant Chlamydiae. We reconstruct and describe key features of the ancient chlamydial symbiont. We propose that it was already adapted to an intracellular lifestyle before the emergence of Archaeplastida, and that several observations are compatible with an essential contribution of Chlamydiae to the evolution of algae and plants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Programming desiccation-tolerance: from plants to seeds to resurrection plants.

    Science.gov (United States)

    Farrant, Jill M; Moore, John P

    2011-06-01

    Desiccation-tolerance (DT) evolved as the key solution to survival on land by the early algal ancestors of terrestrial plants. This 'first' DT involved utilizing rapidly mobilisable repair mechanisms and is still found today in mosses, such as Tortula ruralis, and ferns, such as Mohria caffrorum. The first seed plants lost vegetative DT while investing their seeds with tolerance mechanisms improving their survival in unfavourable environments. The mechanisms of DT in seeds are strongly connected to their developmentally regulated maturation programs. We propose that angiosperm resurrection plants acquired tolerance by re-activating their innate DT mechanisms in their vegetative tissues. Here we review the current hypotheses regarding the genetic evidence for the evolution of DT in resurrection plants. We also present strong evidence showing the activation of seed specific genetic elements in the vegetative tissues of resurrection plants. Copyright © 2011. Published by Elsevier Ltd.

  12. Biogenic synthesis of gold and silver nanoparticles by seed plants.

    Science.gov (United States)

    Iyer, R Indira; Panda, Tapobrata

    2014-02-01

    Nanoparticles have an enormous range of biomedical and environmental applications and can be used for development of various nanodevices for diagnostics and drug delivery. Biogenic production of nanoparticles, that is of silver and gold, by seed plants, especially flowering plants, has evoked considerable interest in the last decade. Different organs of plants as well as callus cultures have been used for the production of these metal nanoparticles. It is possible to regulate the geometry of the nanoparticles by modifying the experimental parameters. In many cases the phytosynthesized gold and silver nanoparticles have been demonstrated to be potentially useful for treatment of various diseases. The production of gold and silver nanoparticles by diverse species of seed plants and their biological activity are discussed in this article.

  13. Growing knowledge: an overview of Seed Plant diversity in Brazil

    OpenAIRE

    Zappi, Daniela C.; Filardi,Fabiana L. Ranzato; Leitman,Paula; Souza, Vinícius C.; Bruno M. T. Walter; José R. Pirani; Morim,Marli P.; de Queiroz, Luciano P.; Cavalcanti,Taciana B.; Mansano, Vidal F.; Forzza,Rafaela C.; Abreu,Maria C.; Acevedo-Rodríguez, Pedro; Agra,Maria de F.; Almeida Jr.,Eduardo B.

    2016-01-01

    An updated inventory of Brazilian seed plants is presented and offers important insights into the country’s biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while th...

  14. The DigitalSeed: An Interactive Toy for Investigating Plants

    Science.gov (United States)

    Cherubini, Mauro; Gash, Hugh; McCloughlin, Thomas

    2008-01-01

    Plant growth, development and reproduction are fundamental concepts in biology; yet there is a recorded lack of motivation for young people to grapple with these concepts. Here we present the "DigitalSeed" toy for making investigations around these concepts more accessible to children through hands-on digital interaction. This is part of an…

  15. Analysis of plant soil seed banks and seed dispersal vectors: Its potential and limits for forensic investigations.

    Science.gov (United States)

    Šumberová, Kateřina; Ducháček, Michal

    2017-01-01

    Plant seeds exhibit many species-specific traits, thus potentially being especially helpful for forensic investigations. Seeds of a broad range of plant species occur in soil seed banks of various habitats and may become attached in large quantities to moving objects. Although plant seeds are now routinely used as trace evidence in forensic practice, only scant information has been published on this topic in the scientific literature. Thus, the standard methods remain unknown to specialists in such botanical subjects as plant ecology and plant geography. These specialists, if made aware of the forensic uses of seeds, could help in development of new, more sophisticated approaches. We aim to bridge the gap between forensic analysts and botanists. Therefore, we explore the available literature and compare it with our own experiences to reveal both the potential and limits of soil seed bank and seed dispersal analysis in forensic investigations. We demonstrate that habitat-specific and thus relatively rare species are of the greatest forensic value. Overall species composition, in terms of species presence/absence and relative abundance can also provide important information. In particular, the ecological profiles of seeds found on any moving object can help us identify the types of environments through which the object had travelled. We discuss the applicability of this approach to various European environments, with the ability to compare seed samples with georeferenced vegetation databases being particularly promising for forensic investigations. We also explore the forensic limitations of soil seed bank and seed dispersal vector analyses.

  16. Seed dispersal by specialist versus generalist foragers: the plant's perspective

    Science.gov (United States)

    Larson, D.L.

    1996-01-01

    I examined the seed dispersal ecology of the stem parasitic plant, desert mistletoe (Phoradendron californicum, Viscaceae), with the objectives of (1) determining the relative effectiveness of specialist and generalist foragers for seed dispersal, (2) determining the extent to which desert mistletoe fruiting characteristics correspond to those predicted for plants attracting specialist versus generalist foragers, and (3) examining the potential consequences of the observed dispersal strategy for mistletoe reproduction. Three species of birds, phainopepla, Gila woodpecker, and northern mockingbird, fed on desert mistletoe at my study site. The specialist, phainopepla, was the most abundant and the most likely to perch in host species, where defecated seeds had a greater probability of lodging in a site suitable for establishment. Gila woodpeckers, although abundant, spent little time in host plants, thus dooming most of the seeds they consumed. Mockingbirds may disperse a small number of seeds, but were abundant enough to consume only a small portion of the available fruits. As expected for plants attracting specialist frugivores, mistletoes produced fruits throughout the 6-month season in which phainopeplas reside in the Sonoran desert. Contrary to expectation, numbers of fruits produced far exceeded the amount that could be consumed by the frugivores at my study site. Fruit crop size was positively related to absolute fruit removal, but not to proportional removal at the scale of the entire study site. However, crop size was positively related to proportional removal within the neighborhood of mistletoes occupying an individual host tree. Frugivores were attracted to infected hosts, host attractiveness increased, although proportional removal of fruit declined, with number of female mistletoes. The observed dispersal ecology of desert mistletoe suggests the likelihood of increasingly clumped distributions of mistletoe plants, as more and more seeds are deposited

  17. A functional phylogenomic view of the seed plants.

    Science.gov (United States)

    Lee, Ernest K; Cibrian-Jaramillo, Angelica; Kolokotronis, Sergios-Orestis; Katari, Manpreet S; Stamatakis, Alexandros; Ott, Michael; Chiu, Joanna C; Little, Damon P; Stevenson, Dennis Wm; McCombie, W Richard; Martienssen, Robert A; Coruzzi, Gloria; Desalle, Rob

    2011-12-01

    A novel result of the current research is the development and implementation of a unique functional phylogenomic approach that explores the genomic origins of seed plant diversification. We first use 22,833 sets of orthologs from the nuclear genomes of 101 genera across land plants to reconstruct their phylogenetic relationships. One of the more salient results is the resolution of some enigmatic relationships in seed plant phylogeny, such as the placement of Gnetales as sister to the rest of the gymnosperms. In using this novel phylogenomic approach, we were also able to identify overrepresented functional gene ontology categories in genes that provide positive branch support for major nodes prompting new hypotheses for genes associated with the diversification of angiosperms. For example, RNA interference (RNAi) has played a significant role in the divergence of monocots from other angiosperms, which has experimental support in Arabidopsis and rice. This analysis also implied that the second largest subunit of RNA polymerase IV and V (NRPD2) played a prominent role in the divergence of gymnosperms. This hypothesis is supported by the lack of 24nt siRNA in conifers, the maternal control of small RNA in the seeds of flowering plants, and the emergence of double fertilization in angiosperms. Our approach takes advantage of genomic data to define orthologs, reconstruct relationships, and narrow down candidate genes involved in plant evolution within a phylogenomic view of species' diversification.

  18. A functional phylogenomic view of the seed plants.

    Directory of Open Access Journals (Sweden)

    Ernest K Lee

    2011-12-01

    Full Text Available A novel result of the current research is the development and implementation of a unique functional phylogenomic approach that explores the genomic origins of seed plant diversification. We first use 22,833 sets of orthologs from the nuclear genomes of 101 genera across land plants to reconstruct their phylogenetic relationships. One of the more salient results is the resolution of some enigmatic relationships in seed plant phylogeny, such as the placement of Gnetales as sister to the rest of the gymnosperms. In using this novel phylogenomic approach, we were also able to identify overrepresented functional gene ontology categories in genes that provide positive branch support for major nodes prompting new hypotheses for genes associated with the diversification of angiosperms. For example, RNA interference (RNAi has played a significant role in the divergence of monocots from other angiosperms, which has experimental support in Arabidopsis and rice. This analysis also implied that the second largest subunit of RNA polymerase IV and V (NRPD2 played a prominent role in the divergence of gymnosperms. This hypothesis is supported by the lack of 24nt siRNA in conifers, the maternal control of small RNA in the seeds of flowering plants, and the emergence of double fertilization in angiosperms. Our approach takes advantage of genomic data to define orthologs, reconstruct relationships, and narrow down candidate genes involved in plant evolution within a phylogenomic view of species' diversification.

  19. Planting seeds for the future of food.

    Science.gov (United States)

    Green, Hilary; Broun, Pierre; Cakmak, Ismail; Condon, Liam; Fedoroff, Nina; Gonzalez-Valero, Juan; Graham, Ian; Lewis, Josette; Moloney, Maurice; Oniang'o, Ruth K; Sanginga, Nteranya; Shewry, Peter; Roulin, Anne

    2016-03-30

    The health and wellbeing of future generations will depend on humankind's ability to deliver sufficient nutritious food to a world population in excess of 9 billion. Feeding this many people by 2050 will require science-based solutions that address sustainable agricultural productivity and enable healthful dietary patterns in a more globally equitable way. This topic was the focus of a multi-disciplinary international conference hosted by Nestlé in June 2015, and provides the inspiration for the present article. The conference brought together a diverse range of expertise and organisations from the developing and industrialised world, all with a common interest in safeguarding the future of food. This article provides a snapshot of three of the recurring topics that were discussed during this conference: soil health, plant science and the future of farming practice. Crop plants and their cultivation are the fundamental building blocks for a food secure world. Whether these are grown for food or feed for livestock, they are the foundation of food and nutrient security. Many of the challenges for the future of food will be faced where the crops are grown: on the farm. Farmers need to plant the right crops and create the right conditions to maximise productivity (yield) and quality (e.g. nutritional content), whilst maintaining the environment, and earning a living. New advances in science and technology can provide the tools and know-how that will, together with a more entrepreneurial approach, help farmers to meet the inexorable demand for the sustainable production of nutritious foods for future generations.

  20. Planting seeds for the future of food

    Science.gov (United States)

    Broun, Pierre; Cakmak, Ismail; Condon, Liam; Fedoroff, Nina; Gonzalez‐Valero, Juan; Graham, Ian; Lewis, Josette; Moloney, Maurice; Oniang'o, Ruth K; Sanginga, Nteranya; Shewry, Peter; Roulin, Anne

    2016-01-01

    Abstract The health and wellbeing of future generations will depend on humankind's ability to deliver sufficient nutritious food to a world population in excess of 9 billion. Feeding this many people by 2050 will require science‐based solutions that address sustainable agricultural productivity and enable healthful dietary patterns in a more globally equitable way. This topic was the focus of a multi‐disciplinary international conference hosted by Nestlé in June 2015, and provides the inspiration for the present article. The conference brought together a diverse range of expertise and organisations from the developing and industrialised world, all with a common interest in safeguarding the future of food. This article provides a snapshot of three of the recurring topics that were discussed during this conference: soil health, plant science and the future of farming practice. Crop plants and their cultivation are the fundamental building blocks for a food secure world. Whether these are grown for food or feed for livestock, they are the foundation of food and nutrient security. Many of the challenges for the future of food will be faced where the crops are grown: on the farm. Farmers need to plant the right crops and create the right conditions to maximise productivity (yield) and quality (e.g. nutritional content), whilst maintaining the environment, and earning a living. New advances in science and technology can provide the tools and know‐how that will, together with a more entrepreneurial approach, help farmers to meet the inexorable demand for the sustainable production of nutritious foods for future generations. © 2015 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26619956

  1. European orchid cultivation – from seed to mature plant

    Directory of Open Access Journals (Sweden)

    Jan Ponert

    2012-02-01

    Full Text Available We describe a method for growing orchids of the genera Dactylorhiza and Ophrys, two European members of the subfamily Orchidoideae, from seeds to mature plants using asymbiotic in vitro cultures and glasshouse pot cultures. Four media were used: two new media 1/4–2 and Mo2 and two modifications of Michl medium (Michl 1988. We also describe a highly efficient technique for seed disinfection using a syringe. We tested the effects of ethanol treatment on Anacmaptis morio (L R. M. Bateman, Pridgeon & M. W. seeds, sugar media composition on Dactylorhiza majalis (Rchb. P. F. Hunt & Summerh., Oeceoclades decaryana (H. Perrier ex Guillaumin & Manguin Garay & Taylor and Ophrys lojaconoi P. Delforge and the effect of kinetin on Dactylorhiza majalis protocorm growth. Sucrose was the best carbon source, while hexose resulted in the inhibition of protocorm development at early stages. The addition of kinetin at 10 mg/l resulted in the formation of the largest protocorms. Ethanol can have positive effect on seed germination when applied for a short time (2 min, while long-time ethanol exposure (60 min can kill the seeds.

  2. Variation in seed size is structured by dispersal syndrome and cone morphology in conifers and other nonflowering seed plants.

    Science.gov (United States)

    Leslie, Andrew B; Beaulieu, Jeremy M; Mathews, Sarah

    2017-02-10

    Seed size varies tremendously in plants and its evolution is influenced by multiple ecological and biological factors that are difficult to disentangle. In this study, we focus on understanding the role of seed dispersal by animals in the evolution of seed size in conifers, the most diverse extant nonflowering seed plant group. Relationships among seed size, dispersal syndrome, climate and cone morphology were analyzed across conifers using quantitative models of character evolution and phylogenetic regression techniques. Dispersal syndrome is a more consistent predictor of seed size within major extant conifer clades than climate. Seeds are generally larger in animal-dispersed than wind-dispersed species, and particular cone morphologies are consistently associated with specific ranges in seed size. Seed size and cone morphology evolve in a correlated manner in many animal-dispersed conifers, following a trade-off that minimizes the total size of the dispersal unit. These relationships are also present in other nonflowering seed plant groups, and have been important in the evolution of seeds and cones at least over the Cenozoic and perhaps over much of the later Mesozoic.

  3. Role of Heavy Metal Pumps in Transport of Zinc from Soil to Seeds of Plants

    DEFF Research Database (Denmark)

    Olsen, Lene Irene

    at this location actively export zinc from the mother plant seed coat. Mutant plants that lack AtHMA2 and AtHMA4 accumulate zinc in the seed coat, and consequently have vastly reduced amounts of zinc inside the seed. The finding that AtHMA2 and AtHMA4 are involved in pumping zinc out of the mother plant seed coat...

  4. How important is long-distance seed dispersal for the regional survival of plant species?

    OpenAIRE

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by first relating plant species' dispersal traits to seed dispersal kernels and then relating the kernels to regional survival of the species. We used a recently developed and tested mechanistic seed di...

  5. Geographic patterns of endemic seed plant genera diversity in China

    OpenAIRE

    Shengbin Chen; Zhiyun Ouyang; Yu Fang; Zhenji Li

    2011-01-01

    Endemism describes the phenomenon that the distribution of individual species/taxa is critically restricted to a specific region. Seed plant genera endemic to China (endemic genera) are those with their main geographic distribution range within the borders of China. The geographic patterns of endemic genera can not only guide conservation planning, but these organisms are also important biological resources. We gath-ered data of 173 localities on environmental and spatial factors, and regiona...

  6. Universality of phloem transport in seed plants.

    Science.gov (United States)

    Jensen, Kåre Hartvig; Liesche, Johannes; Bohr, Tomas; Schulz, Alexander

    2012-06-01

    Since Münch in the 1920s proposed that sugar transport in the phloem vascular system is driven by osmotic pressure gradients, his hypothesis has been strongly supported by evidence from herbaceous angiosperms. Experimental constraints made it difficult to test this proposal in large trees, where the distance between source and sink might prove incompatible with the hypothesis. Recently, the theoretical optimization of the Münch mechanism was shown to lead to surprisingly simple predictions for the dimensions of the phloem sieve elements in relation to that of fast growing angiosperms. These results can be obtained in a very transparent way using a simple coupled resistor model. To test the universality of the Münch mechanism, we compiled anatomical data for 32 angiosperm and 38 gymnosperm trees with heights spanning 0.1-50 m. The species studied showed a remarkable correlation with the scaling predictions. The compiled data allowed calculating stem sieve element conductivity and predicting phloem sap flow velocity. The central finding of this work is that all vascular plants seem to have evolved efficient osmotic pumping units, despite their huge disparity in size and morphology. This contribution extends the physical understanding of phloem transport, and will facilitate detailed comparison between theory and field experiments.

  7. Atmospheric extinction in solar tower plants: the Absorption and Broadband Correction for MOR measurements

    Science.gov (United States)

    Hanrieder, N.; Wilbert, S.; Pitz-Paal, R.; Emde, C.; Gasteiger, J.; Mayer, B.; Polo, J.

    2015-05-01

    Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrating solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in raytracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested and more than 19 months of measurements were collected at the Plataforma Solar de Almería and compared. Both instruments are primarily used to determine the meteorological optical range (MOR). The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED) light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for Concentrating Solar Power (CSP), a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the actual, time-dependent by the collector reflected solar spectrum. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the Absorption and Broadband Correction (ABC) procedure, additional

  8. Atmospheric extinction in solar tower plants: the Absorption and Broadband Correction for MOR measurements

    Directory of Open Access Journals (Sweden)

    N. Hanrieder

    2015-05-01

    Full Text Available Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrating solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in raytracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested and more than 19 months of measurements were collected at the Plataforma Solar de Almería and compared. Both instruments are primarily used to determine the meteorological optical range (MOR. The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for Concentrating Solar Power (CSP, a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the actual, time-dependent by the collector reflected solar spectrum. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the Absorption and Broadband Correction (ABC procedure

  9. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

    Directory of Open Access Journals (Sweden)

    Marta Rueda

    forest amount is of primary importance for the persistence of understory plants, to neglect the impact of fragmentation for some species can lead them to local extinction.

  10. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

    Science.gov (United States)

    Rueda, Marta; Moreno Saiz, Juan Carlos; Morales-Castilla, Ignacio; Albuquerque, Fabio S; Ferrero, Mila; Rodríguez, Miguel Á

    2015-01-01

    primary importance for the persistence of understory plants, to neglect the impact of fragmentation for some species can lead them to local extinction.

  11. Flowers, fruits, seeds, and pollen of Landeenia gen. nov., an extinct sapindalean genus from the Eocene of Wyoming.

    Science.gov (United States)

    Manchester, S R; Hermsen, E J

    2000-12-01

    The new genus Landeenia is recognized on the basis of flowers, pollen, infructescences, fruits, and seeds from the middle Eocene of southwestern and northwestern Wyoming. Landeenia aralioides (MacGinitie) comb.nov. has cymose inflorescences with actinomorphic, bisexual flowers, a pentamerous calyx, about ten stamens, and a superior gynoecium of ∼18 carpels sharing a single style. The fruits are globose to oblate, loculicidally dehiscent capsules, with a persistent calyx, and contain flat, elliptical seeds that are surrounded by a small wing. Pollen removed from the anthers is tricolpate with finely striate sculpture. Although clearly dicotyledonous, the combination of characters found in Landeenia is not known in any modern genus. The familial affinities of the plant, though certainly not with the Araliaceae as previously thought, remain uncertain. However, the combination of characters is consistent with treatment as a member of the Sapindales. The fossil material is thus assigned to the rank of Sapindales-Incertae sedis.

  12. An effective seed protection method for planting Zostera marina (eelgrass) seeds: Implications for their large-scale restoration.

    Science.gov (United States)

    Zhang, Pei-Dong; Fang, Chao; Liu, Jie; Xu, Qiang; Li, Wen-Tao; Liu, Yan-Shan

    2015-06-15

    We describe an innovative method of planting Zostera marina (eelgrass) seeds in which hessian bags filled with high-silted sediments are used as a seed protecting device. Here, we evaluated the effectiveness of the method through a field seed-sowing experiment over a three year period. The suitable seed planting density required by the seeds of Z. marina in this method was also investigated. In the spring following seed distribution, seedling establishment rate of Z. marina subjected to different seed densities of 200-500seedsbag(-1) ranged from 16% to 26%. New eelgrass patches from seed were fully developed and well maintained after 2-3years following distribution. The seed planting density of 400seedsbag(-1) may be the most suitable for the establishment of new eelgrass patches. Our results demonstrate that seed-based restoration can be an effective restoration tool and the technique presented should be considered for future large-scale Z. marina restoration projects. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Effect of Seed Position on Parental Plant on Proportion of Seeds Produced with Nondeep and Intermediate Physiological Dormancy.

    Science.gov (United States)

    Lu, Juan J; Tan, Dun Y; Baskin, Carol C; Baskin, Jerry M

    2017-01-01

    The position in which seeds develop on the parental plant can have an effect on dormancy-break and germination. We tested the hypothesis that the proportion of seeds with intermediate physiological dormancy (PD) produced in the proximal position on a raceme of Isatis violascens plants is higher than that produced in the distal position, and further that this difference is related to temperature during seed development. Plants were watered at 3-day intervals, and silicles and seeds from the proximal (early) and distal (late) positions of racemes on the same plants were collected separately and tested for germination. After 0 and 6 months dry storage at room temperature (afterripening), silicles and seeds were cold stratified for 0-16 weeks and tested for germination. Mean daily maximum and minimum temperatures during development/maturation of the two groups of seeds did not differ. A higher proportion of seeds with the intermediate level than with the nondeep level of PD was produced by silicles in the proximal position than by those in the distal position, while the proportion of seeds with nondeep PD was higher in the distal than in the proximal position of the raceme. The differences were not due only to seed mass. Since temperature and soil moisture conditions were the same during development of the seeds in the raceme, differences in proportion of seeds with intermediate and nondeep PD are attributed to position on parental plant. The ecological consequence of this phenomenon is that it ensures diversity in dormancy-breaking and germination characteristics within a seed cohort, a probable bet-hedging strategy. This is the first demonstration of position effects on level of PD in the offspring.

  14. Responses of plant morphology and seed quality to long-term ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... shows that 1000-seed weight, germination percentage, plant height, fiber root length, height of first ramet, individual .... The shape of L. chinensis seed was thin and ... Animal trampling, especially after rain, compact the topsoil ...

  15. Seed consumption and dispersal of ant-dispersed plants by slugs.

    Science.gov (United States)

    Türke, Manfred; Heinze, Eric; Andreas, Kerstin; Svendsen, Sarah M; Gossner, Martin M; Weisser, Wolfgang W

    2010-07-01

    In beech-dominated forests in Central Europe, many spring geophytes show adaptations to seed dispersal by ants (myrmecochory). Ants, however, can be rare in such moist forests. Motivated by observations of slug feeding on seeds we investigated the seed consumption of two plant species, Anemone nemorosa and Asarum europaeum, by slugs, in a series of experiments. In a seed predation experiment in a beech forest, we found that seed removal was strongly reduced when gastropods were excluded from the seed depots. The contribution of insects, including ants, and rodents to seed removal was relatively less but differed between May and July. In the laboratory, slug species, in particular Arion sp., consumed seeds of both plant species. Slugs either consumed the elaiosomes of seeds or swallowed seeds intact. Swallowed seeds were defecated undamaged and germinated as well as control seeds when buried overwinter, indicating the potential for seed dispersal by slugs. We also recovered seeds of myrmecochores in the faeces of several slugs caught in forests. In a slug release experiment in the forest, slugs moved up to 14.6 m (mean 4.4 m) in 15 h, which is the median gut passage time of seeds based on measurements made in the laboratory. We also found that when slug-defecated seeds were offered to rodents, these were less attractive than control seeds, suggesting that passage through the slug gut reduces seed predation risk. Our results demonstrate that slugs are significant consumers of elaiosomes or entire seeds of ant-dispersed plants and that they can function as seed dispersers of these plants.

  16. Relation between extinction and assisted colonization of plants in the arctic-alpine and boreal regions.

    Science.gov (United States)

    Pykälä, Juha

    2017-06-01

    Assisted colonization of vascular plants is considered by many ecologists an important tool to preserve biodiversity threatened by climate change. I argue that assisted colonization may have negative consequences in arctic-alpine and boreal regions. The observed slow movement of plants toward the north has been an argument for assisted colonization. However, these range shifts may be slow because for many plants microclimatic warming (ignored by advocates of assisted colonization) has been smaller than macroclimatic warming. Arctic-alpine and boreal plants may have limited possibilities to disperse farther north or to higher elevations. I suggest that arctic-alpine species are more likely to be driven to extinction because of competitive exclusion by southern species than by increasing temperatures. If so, the future existence of arctic-alpine and boreal flora may depend on delaying or preventing the migration of plants toward the north to allow northern species to evolve to survive in a warmer climate. In the arctic-alpine region, preventing the dispersal of trees and shrubs may be the most important method to mitigate the negative effects of climate change. The purported conservation benefits of assisted colonization should not be used to promote the migration of invasive species by forestry. © 2016 Society for Conservation Biology.

  17. Atmospheric extinction in solar tower plants: absorption and broadband correction for MOR measurements

    Directory of Open Access Journals (Sweden)

    N. Hanrieder

    2015-08-01

    Full Text Available Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrated solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in ray-tracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested, and more than 19 months of measurements were collected and compared at the Plataforma Solar de Almería. Both instruments are primarily used to determine the meteorological optical range (MOR. The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for concentrated solar power (CSP, a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the time-dependent solar spectrum which is reflected by the collector. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the absorption and broadband correction (ABC procedure

  18. Atmospheric extinction in solar tower plants: absorption and broadband correction for MOR measurements

    Science.gov (United States)

    Hanrieder, N.; Wilbert, S.; Pitz-Paal, R.; Emde, C.; Gasteiger, J.; Mayer, B.; Polo, J.

    2015-08-01

    Losses of reflected Direct Normal Irradiance due to atmospheric extinction in concentrated solar tower plants can vary significantly with site and time. The losses of the direct normal irradiance between the heliostat field and receiver in a solar tower plant are mainly caused by atmospheric scattering and absorption by aerosol and water vapor concentration in the atmospheric boundary layer. Due to a high aerosol particle number, radiation losses can be significantly larger in desert environments compared to the standard atmospheric conditions which are usually considered in ray-tracing or plant optimization tools. Information about on-site atmospheric extinction is only rarely available. To measure these radiation losses, two different commercially available instruments were tested, and more than 19 months of measurements were collected and compared at the Plataforma Solar de Almería. Both instruments are primarily used to determine the meteorological optical range (MOR). The Vaisala FS11 scatterometer is based on a monochromatic near-infrared light source emission and measures the strength of scattering processes in a small air volume mainly caused by aerosol particles. The Optec LPV4 long-path visibility transmissometer determines the monochromatic attenuation between a light-emitting diode (LED) light source at 532 nm and a receiver and therefore also accounts for absorption processes. As the broadband solar attenuation is of interest for solar resource assessment for concentrated solar power (CSP), a correction procedure for these two instruments is developed and tested. This procedure includes a spectral correction of both instruments from monochromatic to broadband attenuation. That means the attenuation is corrected for the time-dependent solar spectrum which is reflected by the collector. Further, an absorption correction for the Vaisala FS11 scatterometer is implemented. To optimize the absorption and broadband correction (ABC) procedure, additional

  19. Seeds of alpine plants are short lived: implications for long-term conservation.

    Science.gov (United States)

    Mondoni, Andrea; Probert, Robin J; Rossi, Graziano; Vegini, Emanuele; Hay, Fiona R

    2011-01-01

    Alpine plants are considered one of the groups of species most sensitive to the direct and indirect threats to ecosystems caused by land use and climate change. Collecting and banking seeds of plant species is recognized as an effective tool for providing propagating material to re-establish wild plant populations and for habitat repair. However, seeds from cold wet environments have been shown to be relatively short lived in storage, and therefore successful long-term seed conservation for alpine plants may be difficult. Here, the life spans of 69 seed lots representing 63 related species from alpine and lowland locations from northern Italy are compared. Seeds were placed into experimental storage at 45 °C and 60 % relative humidity (RH) and regularly sampled for germination. The time taken in storage for viability to fall to 50 % (p(50)) was determined using probit analysis and used as a measure of relative seed longevity between seed lots. Across species, p(50) at 45 °C and 60 % RH varied from 4·7 to 95·5 d. Seed lots from alpine populations/species had significantly lower p(50) values compared with those from lowland populations/species; the lowland seed lots showed a slower rate of loss of germinability, higher initial seed viability, or both. Seeds were progressively longer lived with increased temperature and decreased rainfall at the collecting site. Seeds of alpine plants are short lived in storage compared with those from lowland populations/related taxa. The lower resistance to ageing in seeds of alpine plants may arise from low selection pressure for seed resistance to ageing and/or damage incurred during seed development due to the cool wet conditions of the alpine climate. Long-term seed conservation of several alpine species using conventional seed banking methods will be problematic.

  20. Splash-cup plants accelerate raindrops to disperse seeds.

    Science.gov (United States)

    Amador, Guillermo J; Yamada, Yasukuni; McCurley, Matthew; Hu, David L

    2013-02-01

    The conical flowers of splash-cup plants Chrysosplenium and Mazus catch raindrops opportunistically, exploiting the subsequent splash to disperse their seeds. In this combined experimental and theoretical study, we elucidate their mechanism for maximizing dispersal distance. We fabricate conical plant mimics using three-dimensional printing, and use high-speed video to visualize splash profiles and seed travel distance. Drop impacts that strike the cup off-centre achieve the largest dispersal distances of up to 1 m. Such distances are achieved because splash speeds are three to five times faster than incoming drop speeds, and so faster than the traditionally studied splashes occurring upon horizontal surfaces. This anomalous splash speed is because of the superposition of two components of momentum, one associated with a component of the drop's motion parallel to the splash-cup surface, and the other associated with film spreading induced by impact with the splash-cup. Our model incorporating these effects predicts the observed dispersal distance within 6-18% error. According to our experiments, the optimal cone angle for the splash-cup is 40°, a value consistent with the average of five species of splash-cup plants. This optimal angle arises from the competing effects of velocity amplification and projectile launching angle.

  1. Rapid demise and recovery of plant ecosystems across the end-Permian extinction event

    Science.gov (United States)

    Hochuli, Peter A.; Hermann, Elke; Vigran, Jorunn Os; Bucher, Hugo; Weissert, Helmut

    2010-12-01

    The end-Permian extinction event was the most pronounced biotic and ecological crisis in the history of the Earth. It is assumed that over 80% of marine genera disappeared, and that this event had a major impact on the evolution of marine organisms. The impact of this event on terrestrial biota is poorly known and a matter of controversial discussions. In contrast to the fundamental changes in marine fauna most major groups of plants range from the Late Palaeozoic into the Mesozoic. Consequently the impact of the end-Permian extinction event on the evolution of plants was often regarded as minor. However, major changes in the composition of the plant communities have been documented and a number of catastrophic scenarios have been envisioned — including the almost total destruction of plant ecosystems. Based on expanded sections from the Southern Barents Sea (Northern Norway) we trace mid-latitudinal terrestrial ecosystems across the Permo-Triassic transition with a time resolution in the order of 10 kyr, based on a high resolution C org-isotope stratigraphy. Our results show that the floral turnovers are linked with major changes in the C-isotope record and hence with global carbon cycling. The palynological records document the successive steps in the evolution of terrestrial ecosystems. After gradual changes during the latest Permian, plant ecosystems suffered from a major environmental perturbation leading to a rapid turnover from gymnosperm dominated ecosystems to assemblages dominated by lycopods. The dominance of the lycopods, expressed in a spore-spike, represents a relatively short-lived event in the order of 10 kyr. This perturbation of the terrestrial ecosystems preceded the globally recognized negative δ 13C org isotope spike by up to 100 kyr. It coincides with a first end-Permian negative shift of the C-isotope curve and was probably induced by a first major perturbation of the chemistry of the atmosphere, related to the onset of the volcanic

  2. Why Would Plant Species Become Extinct Locally If Growing Conditions Improve?

    Directory of Open Access Journals (Sweden)

    Koen Kramer, Rienk-Jan Bijlsma, Thomas Hickler, Wilfried Thuiller

    2012-01-01

    Full Text Available Two assumptions underlie current models of the geographical ranges of perennial plant species: 1. current ranges are in equilibrium with the prevailing climate, and 2. changes are attributable to changes in macroclimatic factors, including tolerance of winter cold, the duration of the growing season, and water stress during the growing season, rather than to biotic interactions. These assumptions allow model parameters to be estimated from current species ranges. Deterioration of growing conditions due to climate change, e.g. more severe drought, will cause local extinction. However, for many plant species, the predicted climate change of higher minimum temperatures and longer growing seasons means, improved growing conditions. Biogeographical models may under some circumstances predict that a species will become locally extinct, despite improved growing conditions, because they are based on an assumption of equilibrium and this forces the species range to match the species-specific macroclimatic thresholds. We argue that such model predictions should be rejected unless there is evidence either that competition influences the position of the range margins or that a certain physiological mechanism associated with the apparent improvement in growing conditions negatively affects the species performance. We illustrate how a process-based vegetation model can be used to ascertain whether such a physiological cause exists. To avoid potential modelling errors of this type, we propose a method that constrains the scenario predictions of the envelope models by changing the geographical distribution of the dominant plant functional type. Consistent modelling results are very important for evaluating how changes in species areas affect local functional trait diversity and hence ecosystem functioning and resilience, and for inferring the implications for conservation management in the face of climate change.

  3. Why would plant species become extinct locally if growing conditions improve?

    Science.gov (United States)

    Kramer, Koen; Bijlsma, Rienk-Jan; Hickler, Thomas; Thuiller, Wilfried

    2012-01-01

    Two assumptions underlie current models of the geographical ranges of perennial plant species: 1. current ranges are in equilibrium with the prevailing climate, and 2. changes are attributable to changes in macroclimatic factors, including tolerance of winter cold, the duration of the growing season, and water stress during the growing season, rather than to biotic interactions. These assumptions allow model parameters to be estimated from current species ranges. Deterioration of growing conditions due to climate change, e.g. more severe drought, will cause local extinction. However, for many plant species, the predicted climate change of higher minimum temperatures and longer growing seasons means, improved growing conditions. Biogeographical models may under some circumstances predict that a species will become locally extinct, despite improved growing conditions, because they are based on an assumption of equilibrium and this forces the species range to match the species-specific macroclimatic thresholds. We argue that such model predictions should be rejected unless there is evidence either that competition influences the position of the range margins or that a certain physiological mechanism associated with the apparent improvement in growing conditions negatively affects the species performance. We illustrate how a process-based vegetation model can be used to ascertain whether such a physiological cause exists. To avoid potential modelling errors of this type, we propose a method that constrains the scenario predictions of the envelope models by changing the geographical distribution of the dominant plant functional type. Consistent modelling results are very important for evaluating how changes in species areas affect local functional trait diversity and hence ecosystem functioning and resilience, and for inferring the implications for conservation management in the face of climate change.

  4. Influence of ingredients of motor transport exhausts on the seed productivity of adornment flowering plants

    Directory of Open Access Journals (Sweden)

    О. P. Pryimak

    2009-03-01

    Full Text Available Basic descriptions of the seminal productivity for some ornamental flowering plants under influence of cars’ emissions are presented. Decreasing of the seminal productivity, germinating capacity of seeds and mass of thousand seeds was found. Recommendations on plants using for planting of the cities environment polluted by vehicles emissions are proposed.

  5. Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement.

    Science.gov (United States)

    Jetiyanon, Kanchalee; Wittaya-Areekul, Sakchai; Plianbangchang, Pinyupa

    2008-10-01

    The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.

  6. Plant and metagenomic DNA extraction of mucilaginous seeds.

    Science.gov (United States)

    Ramos, Simone N M; Salazar, Marcela M; Pereira, Gonçalo A G; Efraim, Priscilla

    2014-01-01

    The pulp surrounding the seeds of some fruits is rich in mucilage, carbohydrates, etc. Some seeds are rich in proteins and polyphenols. Fruit seeds, like cacao (Theobroma cacao) and cupuassu (Theobroma grandiflorum), are subjected to fermentation to develop flavor. During fermentation, ethanol is produced [2-6]. All of these compounds are considered as interfering substances that hinder the DNA extraction [4-8]. Protocols commonly used in the DNA extraction in samples of plant origin were used, but without success. Thus, a protocol for DNA samples under different conditions that can be used for similar samples was developed and applied with success. The protocol initially described for RNA samples by Zeng et al. [9] and with changes proposed by Provost et al. [5] was adapted for extracting DNA samples from those described. However, several modifications have been proposed:•Samples were initially washed with petroleum ether for fat phase removal.•RNAse was added to the extraction buffer, while spermidin was removed.•Additional steps of extraction with 5 M NaCl, saturated NaCl and CTAB (10%) were included and precipitation was carried out with isopropanol, followed by washing with ethanol.

  7. Phylogenomics and coalescent analyses resolve extant seed plant relationships.

    Directory of Open Access Journals (Sweden)

    Zhenxiang Xi

    Full Text Available The extant seed plants include more than 260,000 species that belong to five main lineages: angiosperms, conifers, cycads, Ginkgo, and gnetophytes. Despite tremendous effort using molecular data, phylogenetic relationships among these five lineages remain uncertain. Here, we provide the first broad coalescent-based species tree estimation of seed plants using genome-scale nuclear and plastid data By incorporating 305 nuclear genes and 47 plastid genes from 14 species, we identify that i extant gymnosperms (i.e., conifers, cycads, Ginkgo, and gnetophytes are monophyletic, ii gnetophytes exhibit discordant placements within conifers between their nuclear and plastid genomes, and iii cycads plus Ginkgo form a clade that is sister to all remaining extant gymnosperms. We additionally observe that the placement of Ginkgo inferred from coalescent analyses is congruent across different nucleotide rate partitions. In contrast, the standard concatenation method produces strongly supported, but incongruent placements of Ginkgo between slow- and fast-evolving sites. Specifically, fast-evolving sites yield relationships in conflict with coalescent analyses. We hypothesize that this incongruence may be related to the way in which concatenation methods treat sites with elevated nucleotide substitution rates. More empirical and simulation investigations are needed to understand this potential weakness of concatenation methods.

  8. Phylogenomics and coalescent analyses resolve extant seed plant relationships.

    Science.gov (United States)

    Xi, Zhenxiang; Rest, Joshua S; Davis, Charles C

    2013-01-01

    The extant seed plants include more than 260,000 species that belong to five main lineages: angiosperms, conifers, cycads, Ginkgo, and gnetophytes. Despite tremendous effort using molecular data, phylogenetic relationships among these five lineages remain uncertain. Here, we provide the first broad coalescent-based species tree estimation of seed plants using genome-scale nuclear and plastid data By incorporating 305 nuclear genes and 47 plastid genes from 14 species, we identify that i) extant gymnosperms (i.e., conifers, cycads, Ginkgo, and gnetophytes) are monophyletic, ii) gnetophytes exhibit discordant placements within conifers between their nuclear and plastid genomes, and iii) cycads plus Ginkgo form a clade that is sister to all remaining extant gymnosperms. We additionally observe that the placement of Ginkgo inferred from coalescent analyses is congruent across different nucleotide rate partitions. In contrast, the standard concatenation method produces strongly supported, but incongruent placements of Ginkgo between slow- and fast-evolving sites. Specifically, fast-evolving sites yield relationships in conflict with coalescent analyses. We hypothesize that this incongruence may be related to the way in which concatenation methods treat sites with elevated nucleotide substitution rates. More empirical and simulation investigations are needed to understand this potential weakness of concatenation methods.

  9. Allelopatic effects of some medicinal plant essential oils on plant seeds germination

    Directory of Open Access Journals (Sweden)

    ALI SHOKOUHIAN

    2016-04-01

    Full Text Available The effect of essential oils from some medicinal plants on seed germination was studied with the aim of assessing their potential use as bioherbicides. The experiment was conducted as factorial based on completely randomized design (CRD with three replications. Seeds of 3 summer crops including lettuce (Lactuca sativa, pepper (Piper longum and tomato (Solanum lycopersicum were exposed to essential oils of rosemary (Rosmarinus officinalis, thyme (Thymus vulgaris and anise (Pimpinella anisum at 3 different concentrations (25 and 50% diluted and undiluted. Treated seeds were grown in a growth chamber at 25°C for 5 days. The number of germinated seeds in each Petri dish was daily counted. After five days seed germination percentage (Ge was calculated. Biplot analysis was performed using genotype plus genotype environment interaction (GGE method. Results showed that the allelopathic effect on Ge was varied among studied plants, which was mainly due to i differences in the composition of the studied essential oils and ii different allelopathic effects of the studied essential oils on Ge. Accordingly, compared to the individual use, combining several essential oils would have a greater inhibitory effect on Ge of weeds.

  10. Annual Variability in Seed Production by Woody Plants and the Masting Concept: Reassessment of Principles and Relationship to Pollination and Seed Dispersal

    OpenAIRE

    Herrera, Carlos M.; Jordano, Pedro; GUITIÁN, J.; Traveset, Anna

    1998-01-01

    By analyzing 296 published and unpublished data sets describing annual variation in seed output by 144 species of woody plants, this article addresses the following questions. Do plant species naturally fall into distinct groups corresponding to masting and nonmasting habits? Do plant populations generally exhibit significant bimodality in annual seed output? Are there significant relationships between annual variability in seed production and pollination and seed dispersal modes, as predicte...

  11. All about Plant Pollination: Fruit, Flowers & Seeds. Plant Life for Children[TM]. Schlessinger Science Library. [Videotape].

    Science.gov (United States)

    2000

    Flowers are not only pretty, they are also one of the key elements in the process of plant pollination and reproduction that goes from flowers to fruits to seeds! In All About Plant Pollination: Fruit, Flowers & Seeds, young scientists learn about the different parts of a flower through the use of microscopic photography and detailed diagrams.…

  12. All about Plant Pollination: Fruit, Flowers & Seeds. Plant Life for Children[TM]. Schlessinger Science Library. [Videotape].

    Science.gov (United States)

    2000

    Flowers are not only pretty, they are also one of the key elements in the process of plant pollination and reproduction that goes from flowers to fruits to seeds! In All About Plant Pollination: Fruit, Flowers & Seeds, young scientists learn about the different parts of a flower through the use of microscopic photography and detailed diagrams.…

  13. Seed dispersal distances: a typology based on dispersal modes and plant traits

    OpenAIRE

    Vittoz, P.; Engler, R.

    2007-01-01

    The ability of plants to disperse seeds may be critical for their survival under the current constraints of landscape fragmentation and climate change. Seed dispersal distance would therefore be an important variable to include in species distribution models. Unfortunately, data on dispersal distances are scarce, and seed dispersion models only exist for some species with particular dispersal modes. To overcome this lack of knowledge, we propose a simple approach to estimate seed dispersal di...

  14. A Simplified Seed Transformation Method for Obtaining Transgenic Brassica napus Plants

    Institute of Scientific and Technical Information of China (English)

    SONG Li; ZHAO De-gang; WU Yong-jun; TIAN Xiao-e

    2009-01-01

    We report here a seed transformation of sonication-assisted,no-tissue culture to rapidly produce transgenic Brassica napus plants.This method comprises the steps of treating seeds by ultrasonic wave,inoculating Agrobacterium tumefaciens with a recombinant ChlFN-a gene and germinating directly of treatment seed on wet filter papers.The obtained transformants were verified by GUS histochemical assay and nested PCR amplification.It suggests that seed transformation has a potential use in genetic transformation of rape.

  15. Frugivory and the effects of ingestion by bats on the seed germination of three pioneering plants

    Science.gov (United States)

    de Carvalho-Ricardo, Maria C.; Uieda, Wilson; Fonseca, Renata Cristina B.; Rossi, Marcelo N.

    2014-02-01

    The dispersion and seedling establishment of pioneering plants can be favoured by the presence of frugivorous bats because the bats usually improve seed germination after ingestion. Although seed germinability is known to vary greatly after ingestion by different bats, the relative contribution of each bat species to seed germination within plant communities is poorly understood. In this study, we first determined the fauna of frugivorous bats in a semideciduous seasonal forest remnant in southern Brazil and subsequently identified the plant species of the seeds passed through their guts. Second, the germination performance (i.e., germination percentage and speed) of the seeds of three pioneering plants (Piper aduncum, Piper hispidinervum and Solanum granuloso-leprosum) ingested by the most abundant bats was compared with that of the non-ingested seeds (seeds collected from fruits). Additionally, the effects on seed germination of different bat species were compared. During one year, five species of frugivorous bats were caught, and the seeds of eleven identifiable plant species (not counting those of undetermined species) were found in their faeces. We found that the germination performance of the seeds of Piper species was significantly enhanced after ingestion by bats, whereas S. granuloso-leprosum seeds had neutral or reduced germinability when seeds in faeces were compared with pulp-removed seeds. Our results revealed that the bat species that were captured exerted different effects upon seed germination; such a disparity is expected to result in different rates of early establishment of these pioneer plants in tropical forests, most likely affecting forest composition and structure, particularly during the initial stages of succession.

  16. The development of juvenile plants of the hybrid orchid Bratonia after seed cryopreservation.

    Science.gov (United States)

    Popov, A S; Popova, E V; Nikishina, T V; Kolomeytseva, G L

    2004-01-01

    The development of juvenile plants of hybrid Bratonia orchid in vitro after seed storage in liquid nitrogen and the effect of nutrient medium composition on protocorm multiplication and plant regeneration were investigated. Cryopreservation did not inhibit the germination rate of seeds. Protocorms derived from cryopreserved seeds developed faster than protocorms from control (unfrozen) seeds during the first 45 days. But during further culturing, this tendency was not retained and finally protocorms from cryopreserved seeds had the same size as control ones. There were no significant differences in leaf number and shoot length between juvenile plants derived from unfrozen and cryopreserved seeds. We found that among four tested media liquid Morel medium was the most preferable for protocorm multiplication, and liquid ?S medium with half-strength macronutrients was the best one for the development of juvenile plants.

  17. A New Approach to Modify Plant Microbiomes and Traits by Introducing Beneficial Bacteria at Flowering into Progeny Seeds.

    Science.gov (United States)

    Mitter, Birgit; Pfaffenbichler, Nikolaus; Flavell, Richard; Compant, Stéphane; Antonielli, Livio; Petric, Alexandra; Berninger, Teresa; Naveed, Muhammad; Sheibani-Tezerji, Raheleh; von Maltzahn, Geoffrey; Sessitsch, Angela

    2017-01-01

    The microbial component of healthy seeds - the seed microbiome - appears to be inherited between plant generations and can dynamically influence germination, plant performance, and survival. As such, methods to optimize the seed microbiomes of major crops could have far-reaching implications for plant breeding and crop improvement to enhance agricultural food, feed, and fiber production. Here, we describe a new approach to modulate seed microbiomes of elite crop seed embryos and concomitantly design the traits to be mediated by seed microbiomes. Specifically, we discovered that by introducing the endophyte Paraburkholderia phytofirmans PsJN to the flowers of parent plants we could drive its inclusion in progeny seed microbiomes, thereby inducing vertical inheritance to the offspring generation. We demonstrated the introduction of PsJN to seeds of monocot and dicot plant species and the consequential modifications to seed microbiome composition and growth traits in wheat, illustrating the potential role of novel seed-based microbiomes in determining plant traits.

  18. Seed odor mediates an obligate ant-plant mutualism in Amazonian rainforests.

    Science.gov (United States)

    Youngsteadt, Elsa; Nojima, Satoshi; Häberlein, Christopher; Schulz, Stefan; Schal, Coby

    2008-03-25

    Seed dispersal mutualisms are essential for the survival of diverse plant species and communities worldwide. Among invertebrates, only ants have a major role in seed dispersal, and thousands of plant species produce seeds specialized for ant dispersal in "diffuse" multispecies interactions. An outstanding but poorly understood ant-seed mutualism occurs in the Amazonian rainforest, where arboreal ants collect seeds of several epiphyte species and cultivate them in nutrient-rich nests, forming abundant and conspicuous hanging gardens known as ant-gardens (AGs). AG ants and plants are dominant members of lowland Amazonian ecosystems, and their interaction is both specific and obligate, but the means by which ants locate, recognize, and accept their mutualist seeds while rejecting other seeds is unknown. Here we address the chemical and behavioral basis of the AG interaction. We show that workers of the AG ant Camponotus femoratus are attracted to odorants emanating from seeds of the AG plant Peperomia macrostachya, and that chemical cues also elicit seed-carrying behavior. We identify five compounds from P. macrostachya seeds that, as a blend, attract C. femoratus workers. This report of attractive odorants from ant-dispersed seeds illustrates the intimacy and complexity of the AG mutualism and begins to illuminate the chemical basis of this important and enigmatic interaction.

  19. Effect of essential oil of Origanum rotundifolium on some plant pathogenic bacteria, seed germination and plant growth of tomato

    Science.gov (United States)

    Dadaşoǧlu, Fatih; Kotan, Recep; Karagöz, Kenan; Dikbaş, Neslihan; Ćakmakçi, Ramazan; Ćakir, Ahmet; Kordali, Şaban; Özer, Hakan

    2016-04-01

    The aim of this study is to determine effect of Origanum rotundifolium's essential oil on some plant pathogenic bacterias, seed germination and plant growth of tomato. Xanthomonas axanopodis pv. vesicatoria strain (Xcv-761) and Clavibacter michiganensis ssp. michiganensis strain (Cmm) inoculated to tomato seed. The seeds were tested for germination in vitro and disease severity and some plant growth parameters in vivo. In vitro assay, maximum seed germination was observed at 62,5 µl/ml essential oil treatment in seeds inoculated with Xcv-761 and at 62,5 µl/ml essential oil and streptomycin treatment in seeds inoculated with Cmm. The least infected cotiledon number was observed at 500 µg/ml streptomycin treatment in seeds inoculated with Cmm. In vivo assay, maximum seed germination was observed at 250 µl/ml essential oil teratment in tomato inoculated with Cmm. Lowest disease severity, is seen in the CMM infected seeds with 250 µl/ml essential oil application these results were statistically significant when compared with pathogen infected seeds. Similarly, in application conducted with XCV-761 infected seed, the lowest disease severity was observed for seeds as a result of 250 µl/ml essential oil application. Also according to the results obtained from essential oil application of CMM infected seeds conducted with 62,5 µl/ml dose; while disease severity was found statistically insignificant compared to 250 µl/ml to essential oil application, ıt was found statistically significant compared to pathogen infected seeds. The results showed that essential oil of O. rotundifolium has a potential for some suppressed plant disease when it is used in appropriate dose.

  20. Use of tetrazolium (TTC, Germ's and greenhouse plant emergences methods for testing seed vigour of selected ornamental plant species

    Directory of Open Access Journals (Sweden)

    Roman Hołubowicz

    2013-12-01

    Full Text Available In the years 1996-1997 the experiments were carried out on methods to investigate seed vigour of tassel flower (Amaranthus caudatus L., sand pink (Dianthus chinensis L., babies' breath (Gypsophila elegans M.B., sweet pea (Lathyrus odorathus L., African marigold (Tagetes erecta L. and zinnia (Zinnia elegans Jasq.. The main goals of this research were to specify conditions for accelerated ageing (AA of the seeds of a few selected ornamental plant species and to choose the most appropriate methods for their seed vigour evaluation in the laboratory and greenhouse conditions. All used in the experiments seeds came from the commercial seed lots from Polish seed company. Evaluation was carried out on the seed samples with high and low vigour. The latter ones were received through subjecting the seed samples to AA, i.e. by placing them in 100% relative humidity (RH at 44°C, except African marigold-at 42°C, in the darkness and keeping them for 144, 88, 100, 48, 72 and 72 hours, respectively. The tested seed vigour estimated methods included the Germ's method, the 2,3,5-triphenyl tetrazoilum chloride (TTC method and the test of plant emergences in the greenhouse. The high vigour seeds samples were used as a check. The Germ's method was found to be useful to evaluate sand pink, babies' breath and African marigold seed vigour, whereas the TTC method was found to be suitable for vigour evaluation of sand pink, babies' breath and zinnia. At present stage of our knowledge about seed vigour, the plant emergences in the greenhouse method was found to be the best for evaluation of seed vigour of tassel flower, sand pink, babies' breath, sweet pea and zinnia. It is reasonable to combine a few methods of seed vigour evaluation for ornamental plant species.

  1. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions

    DEFF Research Database (Denmark)

    Heleno, R. H.; Olesen, Jens Mogens; Nogales, M.

    2013-01-01

    Alien plants are a growing threat to the Gala´pagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most...... plants were dispersed via two pathways: dryfruited plants were preferentially dispersed by finches, while fleshy fruited species were mostly dispersed by other birds and reptiles....

  2. Loss of animal seed dispersal increases extinction risk in a tropical tree species due to pervasive negative density dependence across life stages.

    Science.gov (United States)

    Caughlin, T Trevor; Ferguson, Jake M; Lichstein, Jeremy W; Zuidema, Pieter A; Bunyavejchewin, Sarayudh; Levey, Douglas J

    2015-01-07

    Overhunting in tropical forests reduces populations of vertebrate seed dispersers. If reduced seed dispersal has a negative impact on tree population viability, overhunting could lead to altered forest structure and dynamics, including decreased biodiversity. However, empirical data showing decreased animal-dispersed tree abundance in overhunted forests contradict demographic models which predict minimal sensitivity of tree population growth rate to early life stages. One resolution to this discrepancy is that seed dispersal determines spatial aggregation, which could have demographic consequences for all life stages. We tested the impact of dispersal loss on population viability of a tropical tree species, Miliusa horsfieldii, currently dispersed by an intact community of large mammals in a Thai forest. We evaluated the effect of spatial aggregation for all tree life stages, from seeds to adult trees, and constructed simulation models to compare population viability with and without animal-mediated seed dispersal. In simulated populations, disperser loss increased spatial aggregation by fourfold, leading to increased negative density dependence across the life cycle and a 10-fold increase in the probability of extinction. Given that the majority of tree species in tropical forests are animal-dispersed, overhunting will potentially result in forests that are fundamentally different from those existing now.

  3. How important is long-distance seed dispersal for the regional survival of plant species?

    NARCIS (Netherlands)

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by fi

  4. How important is long-distance seed dispersal for the regional survival of plant species?

    NARCIS (Netherlands)

    Soons, M.B.; Ozinga, W.A.

    2005-01-01

    Long-distance seed dispersal is generally assumed to be important for the regional survival of plant species. In this study, we quantified the importance of long-distance seed dispersal for regional survival of plant species using wind dispersal as an example. We did this using a new approach, by

  5. Seed dispersal by a captive corvid: the role of the 'Alalā (Corvus hawaiiensis) in shaping Hawai'i's plant communities.

    Science.gov (United States)

    Culliney, Susan; Pejchar, Liba; Switzer, Richard; Ruiz-Gutierrez, Viviana

    2012-09-01

    Species loss can lead to cascading effects on communities, including the disruption of ecological processes such as seed dispersal. The endangered 'Alalā (Corvus hawaiiensis), the largest remaining species of native Hawaiian forest bird, was once common in mesic and dry forests on the Big Island of Hawai'i, but today it exists solely in captivity. Prior to its extinction in the wild, the 'Alalā may have helped to establish and maintain native Hawaiian forest communities by dispersing seeds of a wide variety of native plants. In the absence of 'Alalā, the structure and composition of Hawai'i's forests may be changing, and some large-fruited plants may be dispersal limited, persisting primarily as ecological anachronisms. We fed captive 'Alalā a variety of native fruits, documented behaviors relating to seed dispersal, and measured the germination success of seeds that passed through the gut of 'Alalā relative to the germination success of seeds in control groups. 'Alalā ate and carried 14 native fruits and provided germination benefits to several species by ingesting their seeds. Our results suggest that some plants rely heavily on 'Alalā for these services. In captivity, juvenile birds displayed seed dispersal behaviors more often than adult birds for most fruiting plants in our study. We introduced captive 'Alalā to two large-fruited, dry-forest plants, not previously recorded as 'Alalā food resources, but which may once have been part of their natural diet. The seed dispersal behavior that 'Alalā displayed toward these species supports the inclusion of dry and mesic forests in 'Alalā habitat restoration plans and adds weight to the idea that plant dispersal limitation may contribute to the rarity of these plants. Our study provides evidence that 'Alalā have the capacity to play a vital role in maintaining the diversity of fruiting plants in native Hawaiian forests through seed dispersal and enhanced seed germination, thus adding greater urgency to

  6. Early genome duplications in conifers and other seed plants.

    Science.gov (United States)

    Li, Zheng; Baniaga, Anthony E; Sessa, Emily B; Scascitelli, Moira; Graham, Sean W; Rieseberg, Loren H; Barker, Michael S

    2015-11-01

    Polyploidy is a common mode of speciation and evolution in angiosperms (flowering plants). In contrast, there is little evidence to date that whole genome duplication (WGD) has played a significant role in the evolution of their putative extant sister lineage, the gymnosperms. Recent analyses of the spruce genome, the first published conifer genome, failed to detect evidence of WGDs in gene age distributions and attributed many aspects of conifer biology to a lack of WGDs. We present evidence for three ancient genome duplications during the evolution of gymnosperms, based on phylogenomic analyses of transcriptomes from 24 gymnosperms and 3 outgroups. We use a new algorithm to place these WGD events in phylogenetic context: two in the ancestry of major conifer clades (Pinaceae and cupressophyte conifers) and one in Welwitschia (Gnetales). We also confirm that a WGD hypothesized to be restricted to seed plants is indeed not shared with ferns and relatives (monilophytes), a result that was unclear in earlier studies. Contrary to previous genomic research that reported an absence of polyploidy in the ancestry of contemporary gymnosperms, our analyses indicate that polyploidy has contributed to the evolution of conifers and other gymnosperms. As in the flowering plants, the evolution of the large genome sizes of gymnosperms involved both polyploidy and repetitive element activity.

  7. Floristic characteristics of alien invasive seed plant species in China

    Directory of Open Access Journals (Sweden)

    CONGYAN WANG

    Full Text Available ABSTRACT This study aims to determine the floristic characteristics of alien invasive seed plant species (AISPS in China. There are a total of five hundred and thirteen AISPS, belonging to seventy families and two hundred and eighty-three genera. Seventy families were classified into nine areal types at the family level, and "Cosmopolitan" and "Pantropic" are the two main types. Two hundred and eighty-three genera were classified into twelve areal types at the genus level, and "Pantropic", "Trop. Asia & Amer. disjuncted", and "Cosmopolitan" are the three main types. These results reveal a certain degree of diversity among AISPS in China. The floristic characteristics at the family level exhibit strong pantropic characteristics. Two possible reasons for this are as follows. Firstly, southeastern China is heavily invaded by alien invasive plant species and this region has a mild climate. Secondly, southeastern China is more disturbed by human activities than other regions in China. The floristic characteristics at the genus level display strong pantropic but with abundant temperate characteristics. This may be due to that China across five climatic zones and the ecosystems in which the most alien invasive plant species occur have the same or similar climate with their natural habitat.

  8. Importance of earthworm-seed interactions for the composition and structure of plant communities: A review

    Science.gov (United States)

    Forey, Estelle; Barot, Sébastien; Decaëns, Thibaud; Langlois, Estelle; Laossi, Kam-Rigne; Margerie, Pierre; Scheu, Stefan; Eisenhauer, Nico

    2011-11-01

    Soil seed bank composition and dynamics are crucial elements for the understanding of plant population and community ecology. Earthworms are increasingly recognized as important dispersers and predators of seeds. Through direct and indirect effects they influence either positively or negatively the establishment and survival of seeds and seedlings. Seedling establishment is affected by a variety of earthworm-mediated mechanisms, such as selective seed ingestion and digestion, acceleration or deceleration of germination, and seed transport. Earthworm casts deposited on the soil surface and the entrance of earthworm burrows often contain viable seeds and constitute important regeneration niches for plant seedlings and therefore likely favour specific seed traits. However, the role of earthworms as seed dispersers, mediators of seed bank dynamics and seed predators has not been considered in concert. The overall effect of earthworms on plant communities remains little understood. Most knowledge is based on laboratory studies on temperate species and future work has to explore the biological significance of earthworm-seed interactions under more natural conditions. In this review we summarize the current knowledge on earthworm-seed interactions and discuss factors determining these interactions. We highlight that this interaction may be an underappreciated, yet major driving force for the dynamics of soil seed banks and plant communities which most likely have experienced co-evolutionary processes. Despite the experimental bias, we hypothesize that the knowledge gathered in the present review is of crucial relevance for restoration and conservation ecology. For instance, as earthworms emerge as successful and ubiquitous invaders in various ecosystems, the summarized information might serve as a basis for realistic estimations and modelling of consequences on native plant communities. We depict promising directions of future research and point to the need to consider

  9. Pollination and seed dispersal are the most threatened processes of plant regeneration

    Science.gov (United States)

    Neuschulz, Eike Lena; Mueller, Thomas; Schleuning, Matthias; Böhning-Gaese, Katrin

    2016-07-01

    Plant regeneration is essential for maintaining forest biodiversity and ecosystem functioning, which are globally threatened by human disturbance. Here we present the first integrative meta-analysis on how forest disturbance affects multiple ecological processes of plant regeneration including pollination, seed dispersal, seed predation, recruitment and herbivory. We analysed 408 pairwise comparisons of these processes between near-natural and disturbed forests. Human impacts overall reduced plant regeneration. Importantly, only processes early in the regeneration cycle that often depend on plant-animal interactions, i.e. pollination and seed dispersal, were negatively affected. Later processes, i.e. seed predation, recruitment and herbivory, showed overall no significant response to human disturbance. Conserving pollination and seed dispersal, including the animals that provide these services to plants, should become a priority in forest conservation efforts globally.

  10. Relative rates of synonymous substitutions in the mitochondrial, chloroplast and nuclear genomes of seed plants.

    Science.gov (United States)

    Drouin, Guy; Daoud, Hanane; Xia, Junnan

    2008-12-01

    Previous studies have estimated that, in angiosperms, the synonymous substitution rate of chloroplast genes is three times higher than that of mitochondrial genes and that of nuclear genes is twelve times higher than that of mitochondrial genes. Here we used 12 genes in 27 seed plant species to investigate whether these relative rates of substitutions are common to diverse seed plant groups. We find that the overall relative rate of synonymous substitutions of mitochondrial, chloroplast and nuclear genes of all seed plants is 1:3:10, that these ratios are 1:2:4 in gymnosperms but 1:3:16 in angiosperms and that they go up to 1:3:20 in basal angiosperms. Our results show that the mitochondrial, chloroplast and nuclear genomes of seed plant groups have different synonymous substitutions rates, that these rates are different in different seed plant groups and that gymnosperms have smaller ratios than angiosperms.

  11. Advances in seed conservation of wild plant species: a review of recent research.

    Science.gov (United States)

    Hay, Fiona R; Probert, Robin J

    2013-01-01

    Seed banking is now widely used for the ex situ conservation of wild plant species. Many seed banks that conserve wild species broadly follow international genebank guidelines for seed collection, processing, storage, and management. However, over the last 10-20 years, problems and knowledge gaps have been identified, which have led to more focused seed conservation research on diverse species. For example, there is now greater ecogeographic understanding of seed storage behaviour and of the relative longevity of orthodox seeds, and we are therefore able to predict which species should be conserved using cryostorage techniques; seed development studies have identified when seeds should be harvested for maximal tolerance of desiccation and longevity in storage, as well as highlighting how seed development can vary between species; and there is now a wealth of literature on the dormancy-breaking and germination requirements of wild species which, as well as enabling better management of accessions, will also mean that their use in restoration, species reintroduction, or for evaluation for other applications is possible. Future research may be focused, for example, on nursery and plant production systems for wild plant species that maximize genetic diversity, so that introduced seeds and plant materials have the resilience to cope with future environmental stresses.

  12. Effects of hypobaria and hypoxia on seed germination of six plant species

    Science.gov (United States)

    Tang, Yongkang; Gao, Feng; Guo, Shuangsheng; Li, Fang

    2014-10-01

    Hypobaria (low pressure) is typically associated with hypoxia (low oxygen partial pressure). There are several advantages of growing higher plants under hypobaria in the moon or mars habitat. The objectives of this research were to investigate the seed germination of six plant species under hypobaric and ambient total pressure conditions. Seeds were sown and germinated under three levels of total atmospheric pressure (101, 30 and 10 kPa) and three levels of oxygen partial pressures (21, 6 and 2 kPa) in an 8-day study. Hypoxia (6 or 2 kPa) significantly inhibited all seed germination under three levels of total atmospheric pressure by increasing the electrical conductivity and the optical density, decreasing the seed germination percentage and seed dehydrogenase activity and inhibiting the growth of the shoots and roots. Hypobaria (30 or 10 kPa) markedly improved seed germination and root growth by enhancing the oxygen diffusion rate under hypoxic conditions (6 or 2 kPa). The seeds of three dicot plants (lettuce, Chinese cabbage and cucumber) were more sensitive to hypoxia caused by hypobaria than were those of three monocot plants (maize, wheat and rice); lettuce and cucumber seeds had the highest sensitivity, whereas rice seeds had the lowest sensitivity. This research demonstrates that six experimental seeds can germinate normally under hypobaria (30 kPa), but the oxygen partial pressure should not be less than 6 kPa.

  13. Role of Heavy Metal Pumps in Transport of Zinc from Soil to Seeds of Plants

    DEFF Research Database (Denmark)

    Olsen, Lene Irene

    . In Arabidopsis roots, the heavy metal ATPases AtHMA2 and AtHMA4 are localized to the pericycle cells and are important for the export of zinc, in order for zinc to enter the xylem and get to the shoot. I have identified a new novel role for AtHMA2 and AtHMA4 in the developing seed. The Arabidopsis seed consists...... at this location actively export zinc from the mother plant seed coat. Mutant plants that lack AtHMA2 and AtHMA4 accumulate zinc in the seed coat, and consequently have vastly reduced amounts of zinc inside the seed. The finding that AtHMA2 and AtHMA4 are involved in pumping zinc out of the mother plant seed coat...

  14. Design, Development and Evaluation of a Pneumatic Seeder for Automatic Planting of Seeds in Cellular Trays

    Directory of Open Access Journals (Sweden)

    E Movahedi

    2014-04-01

    Full Text Available For planting fine seeds in cellular trays, an automatic pneumatic seeder was designed, constructed and evaluated. CATIA software was used to design and analysis the system parts of the seeder. Different parts of the seeder, including vibrating seed hopper, vacuum boom, seed picking nozzles, seed tube, pneumatic system and electronic control unit for automation of the seeder, were designed and constructed. The area of nozzle orifice was used to calculate the required pressure of nozzle tip. The seeder was evaluated using two sizes of trays. Experiments were performed with five replications and the error of planting the seeds in the 105 and 390-cellular trays were 1.9 and 0.46 percent, respectively. The time of planting for 105 and 390 cellular trays reduced from 20 min (for manual seeding to 35 s and from 90 min to 160 s, respectively.

  15. Seed dispersal and establishment of endangered plants on Oceanic Islands: the Janzen-Connell model, and the use of ecological analogues.

    Directory of Open Access Journals (Sweden)

    Dennis M Hansen

    Full Text Available BACKGROUND: The Janzen-Connell model states that plant-specific natural enemies may have a disproportionately large negative effect on progeny close to maternal trees. The majority of experimental and theoretical studies addressing the Janzen-Connell model have explored how it can explain existing patterns of species diversity in tropical mainland areas. Very few studies have investigated how the model's predictions apply to isolated oceanic islands, or to the conservation management of endangered plants. Here, we provide the first experimental investigation of the predictions of the Janzen-Connell model on an oceanic island, in a conservation context. In addition, we experimentally evaluate the use of ecological analogue animals to resurrect the functional component of extinct frugivores that could have dispersed seeds away from maternal trees. METHODOLOGY/PRINCIPAL FINDINGS: In Mauritius, we investigated seed germination and seedling survival patterns of the critically endangered endemic plant Syzygium mamillatum (Myrtaceae in relation to proximity to maternal trees. We found strong negative effects of proximity to maternal trees on growth and survival of seedlings. We successfully used giant Aldabran tortoises as ecological analogues for extinct Mauritian frugivores. Effects of gut-passage were negative at the seed germination stage, but seedlings from gut-passed seeds grew taller, had more leaves, and suffered less damage from natural enemies than any of the other seedlings. CONCLUSIONS/SIGNIFICANCE: We provide the first experimental evidence of a distance-dependent Janzen-Connell effect on an oceanic island. Our results potentially have serious implications for the conservation management of rare plant species on oceanic islands, which harbour a disproportionately large fraction of the world's endemic and endangered plants. Furthermore, in contrast to recent controversy about the use of non-indigenous extant megafauna for re

  16. Polyphenols: planting the seeds of treatment for the metabolic syndrome.

    Science.gov (United States)

    Cherniack, E Paul

    2011-06-01

    Greater understanding about the pathogenesis of metabolic syndrome and potential causes suggests that plant polyphenols might be useful as a treatment. Dietary excess energy can be stored in adipocytes, leading to the release of proinflammatory cytokines and adipose-related hormones that cause vascular injury. Plant polyphenols, organic compounds found in numerous plant species and their fruits, are being actively studied as potential treatments for components of the metabolic syndrome. Individual polyphenols that have been examined include resveratrol, quercetin, epigallocathechin-3-gallate, and curcumin. Resveratrol lowers weight, blood pressure, glucose, and insulin resistance in rodents, and a human trial is currently underway. Quercetin decreases lipid and glucose levels in obese rats, and in a human investigation of subjects with the metabolic syndrome has lowered blood pressure without significant alteration of lipids. Epigallocathechin-3-gallate-induced weight loss has attenuated glucose levels and insulin resistance in rodents and improved hemoglobin A(1c) and lipid in human studies. Plant extracts also can be used. Grape seed and chokeberry extracts have decreased blood pressure and lipid levels in small human trials. Other human investigations have shown the beneficial effects of cocoa, coffee, carob, and Momordica charantia. Thus far, most studies have involved a small number of subjects and have been of short duration. Future studies should be designed to account for a disease process in which the pathogenic factors may take place for years before disease manifestations take place, the possibly limited bioavailability of polyphenols, and the potential need to provide combinations or modifications of polyphenols. Published by Elsevier Inc.

  17. Species-specific seed dispersal in an obligate ant-plant mutualism.

    Directory of Open Access Journals (Sweden)

    Elsa Youngsteadt

    Full Text Available Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs. The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism.

  18. Species-specific seed dispersal in an obligate ant-plant mutualism.

    Science.gov (United States)

    Youngsteadt, Elsa; Baca, Jeniffer Alvarez; Osborne, Jason; Schal, Coby

    2009-01-01

    Throughout lowland Amazonia, arboreal ants collect seeds of specific plants and cultivate them in nutrient-rich nests, forming diverse yet obligate and species-specific symbioses called Neotropical ant-gardens (AGs). The ants depend on their symbiotic plants for nest stability, and the plants depend on AGs for substrate and nutrients. Although the AGs are limited to specific participants, it is unknown at what stage specificity arises, and seed fate pathways in AG epiphytes are undocumented. Here we examine the specificity of the ant-seed interaction by comparing the ant community observed at general food baits to ants attracted to and removing seeds of the AG plant Peperomia macrostachya. We also compare seed removal rates under treatments that excluded vertebrates, arthropods, or both. In the bait study, only three of 70 ant species collected P. macrostachya seeds, and 84% of observed seed removal by ants was attributed to the AG ant Camponotus femoratus. In the exclusion experiment, arthropod exclusion significantly reduced seed removal rates, but vertebrate exclusion did not. We provide the most extensive empirical evidence of species specificity in the AG mutualism and begin to quantify factors that affect seed fate in order to understand conditions that favor its departure from the typical diffuse model of plant-animal mutualism.

  19. Phylogeny of seed plants based on all three genomic compartments: extant gymnosperms are monophyletic and Gnetales' closest relatives are conifers.

    Science.gov (United States)

    Bowe, L M; Coat, G; dePamphilis, C W

    2000-04-11

    Efforts to resolve Darwin's "abominable mystery"-the origin of angiosperms-have led to the conclusion that Gnetales and various fossil groups are sister to angiosperms, forming the "anthophytes." Morphological homologies, however, are difficult to interpret, and molecular data have not provided clear resolution of relationships among major groups of seed plants. We introduce two sequence data sets from slowly evolving mitochondrial genes, cox1 and atpA, which unambiguously reject the anthophyte hypothesis, favoring instead a close relationship between Gnetales and conifers. Parsimony- and likelihood-based analyses of plastid rbcL and nuclear 18S rDNA alone and with cox1 and atpA also strongly support a gnetophyte-conifer grouping. Surprisingly, three of four genes (all but nuclear rDNA) and combined three-genome analyses also suggest or strongly support Gnetales as derived conifers, sister to Pinaceae. Analyses with outgroups screened to avoid long branches consistently identify all gymnosperms as a monophyletic sister group to angiosperms. Combined three- and four-gene rooted analyses resolve the branching order for the remaining major groups-cycads separate from other gymnosperms first, followed by Ginkgo and then (Gnetales + Pinaceae) sister to a monophyletic group with all other conifer families. The molecular phylogeny strongly conflicts with current interpretations of seed plant morphology, and implies that many similarities between gnetophytes and angiosperms, such as "flower-like" reproductive structures and double fertilization, were independently derived, whereas other characters could emerge as synapomorphies for an expanded conifer group including Gnetales. An initial angiosperm-gymnosperm split implies a long stem lineage preceding the explosive Mesozoic radiation of flowering plants and suggests that angiosperm origins and homologies should be sought among extinct seed plant groups.

  20. Thieving rodents as substitute dispersers of megafaunal seeds.

    Science.gov (United States)

    Jansen, Patrick A; Hirsch, Ben T; Emsens, Willem-Jan; Zamora-Gutierrez, Veronica; Wikelski, Martin; Kays, Roland

    2012-07-31

    The Neotropics have many plant species that seem to be adapted for seed dispersal by megafauna that went extinct in the late Pleistocene. Given the crucial importance of seed dispersal for plant persistence, it remains a mystery how these plants have survived more than 10,000 y without their mutualist dispersers. Here we present support for the hypothesis that secondary seed dispersal by scatter-hoarding rodents has facilitated the persistence of these large-seeded species. We used miniature radio transmitters to track the dispersal of reputedly megafaunal seeds by Central American agoutis, which scatter-hoard seeds in shallow caches in the soil throughout the forest. We found that seeds were initially cached at mostly short distances and then quickly dug up again. However, rather than eating the recovered seeds, agoutis continued to move and recache the seeds, up to 36 times. Agoutis dispersed an estimated 35% of seeds for >100 m. An estimated 14% of the cached seeds survived to the next year, when a new fruit crop became available to the rodents. Serial video-monitoring of cached seeds revealed that the stepwise dispersal was caused by agoutis repeatedly stealing and recaching each other's buried seeds. Although previous studies suggest that rodents are poor dispersers, we demonstrate that communities of rodents can in fact provide highly effective long-distance seed dispersal. Our findings suggest that thieving scatter-hoarding rodents could substitute for extinct megafaunal seed dispersers of tropical large-seeded trees.

  1. Trait-mediated seed predation, dispersal and survival among frugivore-dispersed plants in a fragmented subtropical forest, Southwest China.

    Science.gov (United States)

    Lai, Xin; Guo, Cong; Xiao, Zhishu

    2014-06-01

    By tracking the fate of individual seeds from 6 frugivore-dispersed plants with contrasting seed traits in a fragmented subtropical forest in Southwest China, we explored how rodent seed predation and hoarding were influenced by seed traits such as seed size, seed coat hardness and seed profitability. Post-dispersal seed fates varied significantly among the 6 seed species and 3 patterns were witnessed: large-seeded species with a hard seed coat (i.e. Choerospoadias axillaries and Diospyros kaki var. silvestris) had more seeds removed, cached and then surviving at caches, and they also had fewer seeds predated but a higher proportion of seeds surviving at the source; medium-sized species with higher profitability and thinner seed coat (i.e. Phoebe zhennan and Padus braohypoda) were first harvested and had the lowest probability of seeds surviving either at the source or at caches due to higher predation before or after removal; and small-seeded species with lower profitability (i.e. Elaeocarpus japonicas and Cornus controversa) had the highest probability of seeds surviving at the source but the lowest probability of seeds surviving at caches due to lower predation at the source and lower hoarding at caches. Our study indicates that patterns of seed predation, dispersal and survival among frugivore-dispersed plants are highly determined by seed traits such as seed size, seed defense and seed profitability due to selective predation and hoarding by seed-eating rodents. Therefore, trait-mediated seed predation, dispersal and survival via seed-eating rodents can largely affect population and community dynamics of frugivore-dispersed plants in fragmented forests.

  2. Sowing quality of seeds sunflower, depending on the influence of plant growth regulators and protectants

    OpenAIRE

    Буряк, Ю. І.; Огурцов, Ю. Є.; Чернобаб, О. В.; Клименко, І. І.

    2014-01-01

    Aim. The aim of this work was to study the influence of plant growth regulators and protectants on the sowing quality of seeds parental forms and hybrids of sunflower.Methodology and materials. Research conducted in the Plant Production Institute named after V.Ya. Yuriev NAAS. The predecessor of sunflower – winter wheat. Sunflower seeds parent lines Сх1010А, Х720В, Х526В and hybrids F1 Romance and Maximus were sown in optimal terms with the seeding norm of 57 thousand pieces of viable seeds p...

  3. Seed dispersal and germination traits of 70 plant species inhabiting the Gurbantunggut Desert in northwest China.

    Science.gov (United States)

    Liu, Huiliang; Zhang, Daoyuan; Yang, Xuejun; Huang, Zhenying; Duan, Shimin; Wang, Xiyong

    2014-01-01

    Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude) of seed mass were smaller and narrower than those in other floras (5-8 orders of magnitude), which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory), and anemochorous species were most abundant. Seed mass (F = 3.50, P = 0.01), seed size (F = 8.31, P seed shape (F = 2.62, P = 0.04) differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight) (P = 0.15), seed size (P = 0.38), or seed shape (variance) (P = 0.95) and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F = 3.64, P = 0.01) and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces.

  4. Seed Dispersal and Germination Traits of 70 Plant Species Inhabiting the Gurbantunggut Desert in Northwest China

    Directory of Open Access Journals (Sweden)

    Huiliang Liu

    2014-01-01

    Full Text Available Seed dispersal and germination were examined for 70 species from the cold Gurbantunggut Desert in northwest China. Mean and range (3 orders of magnitude of seed mass were smaller and narrower than those in other floras (5–8 orders of magnitude, which implies that selection favors relatively smaller seeds in this desert. We identified five dispersal syndromes (anemochory, zoochory, autochory, barochory, and ombrohydrochory, and anemochorous species were most abundant. Seed mass (F=3.50, P=0.01, seed size (F=8.31, P<0.01, and seed shape (F=2.62, P=0.04 differed significantly among the five dispersal syndromes and barochorous species were significantly smaller and rounder than the others. There were no significant correlations between seed mass (seed weight (P=0.15, seed size (P=0.38, or seed shape (variance (P=0.95 and germination percentage. However, germination percentages differed significantly among the dispersal syndromes (F=3.64, P=0.01 and seeds of ombrohydrochorous species had higher germination percentages than those of the other species. In the Gurbantunggut Desert, the percentage of species with seed dormancy was about 80%. In general, our studies suggest that adaptive strategies in seed dispersal and germination of plants in this area are closely related to the environment in which they live and that they are influenced by natural selection forces.

  5. Seed dispersal networks in the Galápagos and the consequences of alien plant invasions

    OpenAIRE

    Heleno, Rubén H.; Olesen, Jens M.; Nogales, Manuel; Vargas, Pablo; Traveset, Anna

    2013-01-01

    Alien plants are a growing threat to the Galápagos unique biota. We evaluated the impact of alien plants on eight seed dispersal networks from two islands of the archipelago. Nearly 10 000 intact seeds from 58 species were recovered from the droppings of 18 bird and reptile dispersers. The most dispersed invaders were Lantana camara, Rubus niveus and Psidium guajava, the latter two likely benefiting from an asynchronous fruit production with most native plants, which facilitate their consumpt...

  6. Surface structure and properties of plant seed oil bodies.

    Science.gov (United States)

    Tzen, J T; Huang, A H

    1992-04-01

    Storage triacylglycerols (TAG) in plant seeds are present in small discrete intracellular organelles called oil bodies. An oil body has a matrix of TAG, which is surrounded by phospholipids (PL) and alkaline proteins, termed oleosins. Oil bodies isolated from mature maize (Zea mays) embryos maintained their discreteness, but coalesced after treatment with trypsin but not with phospholipase A2 or C. Phospholipase A2 or C exerted its activity on oil bodies only after the exposed portion of oleosins had been removed by trypsin. Attempts were made to reconstitute oil bodies from their constituents. TAG, either extracted from oil bodies or of a 1:2 molar mixture of triolein and trilinolein, in a dilute buffer were sonicated to produce droplets of sizes similar to those of oil bodies; these droplets were unstable and coalesced rapidly. Addition of oil body PL or dioleoyl phosphatidylcholine, with or without charged stearylamine/stearic acid, or oleosins, to the medium before sonication provided limited stabilization effects to the TAG droplets. High stability was achieved only when the TAG were sonicated with both oil body PL (or dioleoyl phosphatidylcholine) and oleosins of proportions similar to or higher than those in the native oil bodies. These stabilized droplets were similar to the isolated oil bodies in chemical properties, and can be considered as reconstituted oil bodies. Reconstituted oil bodies were also produced from TAG of a 1:2 molar mixture of triolein and trilinolein, dioleoyl phosphatidylcholine, and oleosins from rice (Oryza sativa), wheat (Triticum aestivum), rapeseed (Brassica napus), soybean (Glycine max), or jojoba (Simmondsia chinensis). It is concluded that both oleosins and PL are required to stabilize the oil bodies and that oleosins prevent oil bodies from coalescing by providing steric hindrance. A structural model of an oil body is presented. The current findings on seed oil bodies could be extended to the intracellular storage lipid

  7. The effect of hydrostatic vs. shock pressure treatment of plant seeds

    Science.gov (United States)

    Mustey, A.; Leighs, J. A.; Appleby-Thomas, G. J.; Wood, D. C.; Hazael, R.; McMillan, P. F.; Hazell, P. J.

    2014-05-01

    The hydrostatic pressure and shock response of plant seeds has been investigated antecedently, primarily driven by interest in reducing bacterial contamination of crops and the theory of panspermia, respectively. However, comparisons have not previously been made between these two methods ofapplying pressure to plant seeds. Here such a comparison has been undertaken based on the premise that any correlations in collected data may provide a route to inform understanding of damage mechanisms in the seeds under test. In this work two varieties of plant seeds were subjected to hydrostatic pressure via a non-end-loaded piston cylinder setup and shock compression via employment of a 50 mm bore, single stage gas gun using the flyer plate technique. Results from germination tests of recovered seed samples have been compared and contrasted, and initial conclusions made regarding causes of trends in the resultant data-set. Data collected has shown that cress seeds are extremely resilient to static loading, whereas the difference in the two forms of loading is negligible for lettuce seeds. Germination time has been seen to extend dramatically following static loading of cress seeds to greater than 0.4 GPa. In addition, the cut-off pressure previously seen to cause 0% germination in dynamic experiments performed on cress seeds has now also been seen in lettuce seeds.

  8. Seed dispersal by ants and its consequences for the phenology of plants : a study system for mutualistic animal plant interactions

    OpenAIRE

    Oberrath, Reik

    2000-01-01

    The hypothesis was tested that ant dispersed plant species are adapted to the seasonal variation in ant activity, i.e. that ant dispersed plant species produce ripe fruits when the activity of their seed dispersers is especially high. Two testable predictions of this hypothesis exist: 1. Ant dispersed and differently dispersed plant species differ in their seasonal development, i.e. ant dispersed plant species fruit (flower) earlier or later in the year than other plant species. Floristic inv...

  9. Single-Copy Genes as Molecular Markers for Phylogenomic Studies in Seed Plants.

    Science.gov (United States)

    Li, Zhen; De La Torre, Amanda R; Sterck, Lieven; Cánovas, Francisco M; Avila, Concepción; Merino, Irene; Cabezas, José Antonio; Cervera, María Teresa; Ingvarsson, Pär K; Van de Peer, Yves

    2017-05-01

    Phylogenetic relationships among seed plant taxa, especially within the gymnosperms, remain contested. In contrast to angiosperms, for which several genomic, transcriptomic and phylogenetic resources are available, there are few, if any, molecular markers that allow broad comparisons among gymnosperm species. With few gymnosperm genomes available, recently obtained transcriptomes in gymnosperms are a great addition to identifying single-copy gene families as molecular markers for phylogenomic analysis in seed plants. Taking advantage of an increasing number of available genomes and transcriptomes, we identified single-copy genes in a broad collection of seed plants and used these to infer phylogenetic relationships between major seed plant taxa. This study aims at extending the current phylogenetic toolkit for seed plants, assessing its ability for resolving seed plant phylogeny, and discussing potential factors affecting phylogenetic reconstruction. In total, we identified 3,072 single-copy genes in 31 gymnosperms and 2,156 single-copy genes in 34 angiosperms. All studied seed plants shared 1,469 single-copy genes, which are generally involved in functions like DNA metabolism, cell cycle, and photosynthesis. A selected set of 106 single-copy genes provided good resolution for the seed plant phylogeny except for gnetophytes. Although some of our analyses support a sister relationship between gnetophytes and other gymnosperms, phylogenetic trees from concatenated alignments without 3rd codon positions and amino acid alignments under the CAT + GTR model, support gnetophytes as a sister group to Pinaceae. Our phylogenomic analyses demonstrate that, in general, single-copy genes can uncover both recent and deep divergences of seed plant phylogeny. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  10. The signature of seeds in resurrection plants: a molecular and physiological comparison of desiccation tolerance in seeds and vegetative tissues.

    Science.gov (United States)

    Illing, Nicola; Denby, Katherine J; Collett, Helen; Shen, Arthur; Farrant, Jill M

    2005-11-01

    Desiccation-tolerance in vegetative tissues of angiosperms has a polyphyletic origin and could be due to 1) appropriation of the seed-specific program of gene expression that protects orthodox seeds against desiccation, and/or 2) a sustainable version of the abiotic stress response. We tested these hypotheses by comparing molecular and physiological data from the development of orthodox seeds, the response of desiccation-sensitive plants to abiotic stress, and the response of desiccation-tolerant plants to extreme water loss. Analysis of publicly-available gene expression data of 35 LEA proteins and 68 anti-oxidant enzymes in the desiccation-sensitive Arabidopsis thaliana identified 13 LEAs and 4 anti-oxidants exclusively expressed in seeds. Two (a LEA6 and 1-cys-peroxiredoxin) are not expressed in vegetative tissues in A. thaliana, but have orthologues that are specifically activated in desiccating leaves of Xerophyta humilis. A comparison of antioxidant enzyme activity in two desiccation-sensitive species of Eragrostis with the desiccation-tolerant E. nindensis showed equivalent responses upon initial dehydration, but activity was retained at low water content in E. nindensis only. We propose that these antioxidants are housekeeping enzymes and that they are protected from damage in the desiccation-tolerant species. Sucrose is considered an important protectant against desiccation in orthodox seeds, and we show that sucrose accumulates in drying leaves of E. nindensis, but not in the desiccation-sensitive Eragrostis species. The activation of "seed-specific" desiccation protection mechanisms (sucrose accumulation and expression of LEA6 and 1-cys-peroxiredoxin genes) in the vegetative tissues of desiccation-tolerant plants points towards acquisition of desiccation tolerance from seeds.

  11. Preliminary design, construction and evaluation of robot of tomato seed planting for the trays of greenhouse

    Directory of Open Access Journals (Sweden)

    J Ghezavati

    2015-09-01

    Full Text Available Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of it was equal to 5,887,715 tons with an average production of 117,887 tons in 4352 hectares in the provinces, respectively. Having high production volume and quality, costly hybrid seeds are currently used for the major planting areas of vegetable in Iran. Most of the used transplanted seedlings are 83%. Since the seeds are expensive, the percentage of seedlings and healthy and disease-free seeds should be used for maximized germination and be transferred to the fields of open space. Preparing seedlings in transplanting trays is a technology to respond to this need. Trays are covered with a layer of Peat and Miculite fertilizers. Then, one seed is manually placed in each cell after gauging and preparing a suitable field. However, manually placing seeds is time-consuming and requires hard labor. Sixteen working labors per hour are required for 15 × 7 cell in order to have 10200 seedlings grown in 100 trays. Due to lack of adequate labor, production capacity of greenhouses is reduced, especially in the farming season when finding labor for planting vegetable sprouts is laborious. Therefore, mechanizing tray seeding operations is essential to increase the capacity of the growing industry of greenhouses in Iran. Materials and Methods: Initially, the tomato seeds were examined in the laboratory. The most important parameters of the study included size, shape, weight, the speed of getting out of the tank and the minimum carrying speed. Then, a vacuum-based single seed picking unit was prepared to investigate the factors influencing the design, so that a single tomato seed can be harvested from the masses. The most important factors considered in the

  12. Forest succession and population viability of grassland plants: long repayment of extinction debt in Primula veris.

    Science.gov (United States)

    Lehtilä, Kari; Dahlgren, Johan P; Garcia, Maria Begoña; Leimu, Roosa; Syrjänen, Kimmo; Ehrlén, Johan

    2016-05-01

    Time lags in responses of organisms to deteriorating environmental conditions delay population declines and extinctions. We examined how local processes at the population level contribute to extinction debt, and how cycles of habitat deterioration and recovery may delay extinction. We carried out a demographic analysis of the fate of the grassland perennial Primula veris after the cessation of grassland management, where we used either a unidirectional succession model for forest habitat or a rotation model with a period of forest growth followed by a clear-cut and a new successional cycle. The simulations indicated that P. veris populations may have an extinction time of decades to centuries after a detrimental management change. A survey of the current incidence and abundance of P. veris in sites with different histories of afforestation confirmed the simulation results of low extinction rates. P. veris had reduced incidence and abundance only at sites with at least 100 years of forest cover. Time to extinction in simulations was dependent on the duration of the periods with favourable and unfavourable conditions after management cessation, and the population sizes and growth rates in these periods. Our results thus suggest that the ability of a species to survive is a complex function of disturbance regimes, rates of successional change, and the demographic response to environmental changes. Detailed demographic studies over entire successional cycles are therefore essential to identify the environmental conditions that enable long-term persistence and to design management for species experiencing extinction debts.

  13. Naturally occurring phenanthrene degrading bacteria associated with seeds of various plant species.

    Science.gov (United States)

    Fernet, Jennifer L; Lawrence, John R; Germida, James J

    2016-01-01

    Seeds of 11 of 19 plant species tested yielded naturally occurring phenanthrene degrading bacteria when placed on phenanthrene impression plates. Seed associated phenanthrene degrading bacteria were mostly detected on caragana, Canada thistle, creeping red fescue, western wheatgrass, and tall wheat grass. Based on 16S rRNA analysis the most common bacteria isolated from these seeds were strains belonging to the genera Enterobacteria, Erwinia, Burkholderia, Pantoea, Pseudomonas, and Sphingomonas. These plants may provide an excellent source of pre-adapted bacterial-plant associations highly suitable for use in remediation of contaminated soil environments.

  14. Generalist birds promote tropical forest regeneration and increase plant diversity via rare-biased seed dispersal.

    Science.gov (United States)

    Carlo, Tomás A; Morales, Juan M

    2016-07-01

    Regenerated forests now compose over half of the world's tropical forest cover and are increasingly important as providers of ecosystem services, freshwater, and biodiversity conservation. Much of the value and functionality of regenerating forests depends on the plant diversity they contain. Tropical forest diversity is strongly shaped by mutualistic interactions between plants and fruit-eating animals (frugivores) that disperse seeds. Here we show how seed dispersal by birds can influence the speed and diversity of early successional forests in Puerto Rico. For two years, we monitored the monthly fruit production of bird-dispersed plants on a fragmented landscape, and measured seed dispersal activity of birds and plant establishment in experimental plots located in deforested areas. Two predominantly omnivorous bird species, the Northern Mockingbird (Mimus polyglottos) and the Gray Kingbird (Tyrannus dominicensis), proved critical for speeding up the establishment of woody plants and increasing the species richness and diversity of the seed rain in deforested areas. Seed dispersal by these generalists increased the odds for rare plant species to disperse and establish in experimental forest-regeneration plots. Results indicate that birds that mix fruit and insects in their diets and actively forage across open and forested habitats can play keystone roles in the regeneration of mutualistic plant-animal communities. Furthermore, our analyses reveal that rare-biased (antiapostatic) frugivory and seed dispersal is the mechanism responsible for increasing plant diversity in the early-regenerating community. © 2016 by the Ecological Society of America.

  15. Isolation and characterisation of plant defensins from seeds of Asteraceae, Fabaceae, Hippocastanaceae and Saxifragaceae.

    Science.gov (United States)

    Osborn, R W; De Samblanx, G W; Thevissen, K; Goderis, I; Torrekens, S; Van Leuven, F; Attenborough, S; Rees, S B; Broekaert, W F

    1995-07-17

    From seeds of Aesculus hippocastanum, Clitoria ternatea, Dahlia merckii and Heuchera sanguinea five antifungal proteins were isolated and shown to be homologous to plant defensins previously characterised from radish seeds and gamma-thionins from Poaceae seeds. Based on the spectrum of their antimicrobial activity and the morphological distortions they induce on fungi the peptides can be divided into two classes. The peptides did not inhibit any of three different alpha-amylases.

  16. Barley seed coating with free and immobilized alkaline phosphatase to improve P uptake and plant growth

    OpenAIRE

    Pilar Izquierdo, María Concepción; Ortega Santamaría, Natividad; Pérez Mateos, Manuel; Busto Núñez, Mª Dolores

    2012-01-01

    Coating barley seeds with free and immobilized alkaline phosphatase was investigated as a potential means to enhance plant utilization of accumulated soil phosphorus (P). Two coating techniques were studied: film-coating and pelleting. The highest phosphatase activity retention in the coating layer, ranging from 0·48 to 0·67, was observed when seeds were film-coated with phosphatase–polyresorcinol complex (PPC). The germination of seeds film-coated or pelleted with alkaline phosph...

  17. Seed bank and big sagebrush plant community composition in a range margin for big sagebrush

    Science.gov (United States)

    Martyn, Trace E.; Bradford, John B.; Schlaepfer, Daniel R.; Burke, Ingrid C.; Laurenroth, William K.

    2016-01-01

    The potential influence of seed bank composition on range shifts of species due to climate change is unclear. Seed banks can provide a means of both species persistence in an area and local range expansion in the case of increasing habitat suitability, as may occur under future climate change. However, a mismatch between the seed bank and the established plant community may represent an obstacle to persistence and expansion. In big sagebrush (Artemisia tridentata) plant communities in Montana, USA, we compared the seed bank to the established plant community. There was less than a 20% similarity in the relative abundance of species between the established plant community and the seed bank. This difference was primarily driven by an overrepresentation of native annual forbs and an underrepresentation of big sagebrush in the seed bank compared to the established plant community. Even though we expect an increase in habitat suitability for big sagebrush under future climate conditions at our sites, the current mismatch between the plant community and the seed bank could impede big sagebrush range expansion into increasingly suitable habitat in the future.

  18. Plant spacing and pollen quantity on yield and quality of squash seeds

    Directory of Open Access Journals (Sweden)

    Lima Márcio S. de

    2003-01-01

    Full Text Available Squash seeds yield and quality can be improved by proper population plant spacing and the pollen quantity, which influences the pollination quality and fertilization. Nine experiments were conducted as a factorial combination of three spacing between plants (0.8 x 0.3, 0.8 x 0.6 and 0.8 x 0.9 m, two quantities of pollen (50% of an anther and another entire one and natural insect pollination. Seed and fruit production parameters, and seed quality were evaluated. A randomized complete block design, five replications, with ten plants per plot was adopted. Larger plant spacing increased the average number of mature fruits and seed yield per plant. Seed yield was directly proportional to the amount of pollen used during pollination. Higher amounts of pollen resulted in higher seed yield per area, but the plant spacing did not affect this characteristic. Manual pollination, using a whole anther, did not differ from natural pollination in relation to seed yield and quality.

  19. The effect of hydrostatic vs. shock pressure treatment on plant seeds

    Science.gov (United States)

    Mustey, Adrian; Leighs, James; Appleby-Thomas, Gareth; Wood, David; Hazael, Rachael; McMillan, Paul; Hazell, Paul

    2013-06-01

    The hydrostatic pressure and shock response of plant seeds have both been previously investigated (primarily driven by an interest in reducing bacterial contamination of crops and the theory of panspermia respectively). However, comparisons have not previously been made between these two methods of applying pressure to plant seeds. Here such a comparison has been undertaken based on the premise that any correlations in such data may provide a route to inform understanding of damage mechanisms in the seeds under test. In this work two varieties of plant seeds were subjected to hydrostatic pressure via a non-end-loaded piston cylinder set-up and shock compression via employment of a 50-mm bore, single stage gas gun using the flyer-plate technique. Results from germination tests of recovered seed samples have been compared and contrasted, and initial conclusions made regarding causes of trends in the resultant data-set.

  20. EFFECT OF SOME PLANT EXTRACT AGAINST SEED BORNE INFECTION OF COLLECTOTRICHUM DESTRUCTIVUM ON VIGNA UNIGUCULATA L.

    Directory of Open Access Journals (Sweden)

    Umesh P. Mogle1 and

    2012-06-01

    Full Text Available The cowpea, Vigna unguiculata L. Walp is an ancient food crop, suffering from many fungal diseases. Collectotrichum destructivum is a harmful seed borne pathogen causing disease to the cowpea plant. Control of seed borne infection would be a possible means of reducing losses due to this disease, attempts were made, fungal species isolated from cowpea seeds were used as inocula. The effects of leaf extracts of Argemone mexicana L., Semecarpus anacardium L., Cassia fistula L., Tephrosia purpurea (L. Pers., were evaluated for the control of Collectotrichum destructivum on seeds of cowpea. The seeds were soaked in sterile distilled water extract (10, 20 and 30%, w/v of the leaves for 5, 10 and 15 h. All these plant extracts had significant inhibitory growth effect on the fungal pathogen. Argemone mexicana extract was more effective followed by Semecarpus anacardium, Cassia fistula and Tephrosia purpurea plant extracts and compared favorably with benomyl in the control of the pathogen.

  1. Fruitful factors: what limits seed production of flowering plants in the alpine?

    Science.gov (United States)

    Straka, Jason R; Starzomski, Brian M

    2015-05-01

    Predicting demographic consequences of climate change for plant communities requires understanding which factors influence seed set, and how climate change may alter those factors. To determine the effects of pollen availability, temperature, and pollinators on seed production in the alpine, we combined pollen-manipulation experiments with measurements of variation in temperature, and abundance and diversity of potential pollinators along a 400-m elevation gradient. We did this for seven dominant species of flowering plants in the Coast Range Mountains, British Columbia, Canada. The number of viable seeds set by plants was influenced by pollen limitation (quantity of pollen received), mate limitation (quality of pollen), temperature, abundance of potential pollinators, seed predation, and combinations of these factors. Early flowering species (n = 3) had higher seed set at high elevation and late-flowering species (n = 4) had higher seed set at low elevation. Degree-days >15 °C were good predictors of seed set, particularly in bee-pollinated species, but had inconsistent effects among species. Seed production in one species, Arnica latifolia, was negatively affected by seed-predators (Tephritidae) at mid elevation, where there were fewer frost-hours during the flowering season. Anemone occidentalis, a fly-pollinated, self-compatible species had high seed set at all elevations, likely due to abundant potential pollinators. Simultaneously measuring multiple factors affecting reproductive success of flowering plants helped identify which factors were most important, providing focus for future studies. Our work suggests that responses of plant communities to climate change may be mediated by flowering time, pollination syndrome, and susceptibility to seed predators.

  2. Both host-plant phylogeny and chemistry have shaped the African seed-beetle radiation.

    Science.gov (United States)

    Kergoat, Gaël J; Delobel, Alex; Fédière, Gilles; Rü, Bruno Le; Silvain, Jean-François

    2005-06-01

    For the last 40 years, many authors have attempted to characterize the main patterns of plant-insect evolutionary interactions and understand their causes. In the present work on African seed-beetles (Coleoptera: Bruchidae), we have performed a 10-year field work to sample seeds of more than 300 species of potential host-plants (from the family Fabaceae), to obtain bruchids by rearing. This seed sampling in the field was followed by the monitoring of adult emergences which gave us the opportunity to identify host-plant use accurately. Then, by using molecular phylogenetics (on a combined data set of four genes), we have investigated the relationships between host-plant preferences and insect phylogeny. Our objectives were to investigate the level of taxonomic conservatism in host-plant fidelity and host-plant chemistry. Our results indicate that phylogenetically related insects are associated with phylogenetically related host-plants but the phylogeny of the latter cannot alone explain the observed patterns. Major host shifts from Papilionoideae to Mimosoideae subfamilies have happened twice independently suggesting that feeding specialization on a given host-plant group is not always a dead end in seed-beetles. If host-plant taxonomy and chemistry in legumes generally provide consistent data, it appears that the nature of the seed secondary compounds may be the major factor driving the diversification of a large clade specializing on the subfamily Mimosoideae in which host-plant taxonomy is not consistent with chemical similarity.

  3. Pantoea allii sp. nov., isolated from onion plants and seed.

    Science.gov (United States)

    Brady, Carrie L; Goszczynska, Teresa; Venter, Stephanus N; Cleenwerck, Ilse; De Vos, Paul; Gitaitis, Ronald D; Coutinho, Teresa A

    2011-04-01

    Eight yellow-pigmented, Gram-negative, rod-shaped, oxidase-negative, motile, facultatively anaerobic bacteria were isolated from onion seed in South Africa and from an onion plant exhibiting centre rot symptoms in the USA. The isolates were assigned to the genus Pantoea on the basis of phenotypic and biochemical tests. 16S rRNA gene sequence analysis and multilocus sequence analysis (MLSA), based on gyrB, rpoB, infB and atpD sequences, confirmed the allocation of the isolates to the genus Pantoea. MLSA further indicated that the isolates represented a novel species, which was phylogenetically most closely related to Pantoea ananatis and Pantoea stewartii. Amplified fragment length polymorphism analysis also placed the isolates into a cluster separate from P. ananatis and P. stewartii. Compared with type strains of species of the genus Pantoea that showed >97 % 16S rRNA gene sequence similarity with strain BD 390(T), the isolates exhibited 11-55 % whole-genome DNA-DNA relatedness, which confirmed the classification of the isolates in a novel species. The most useful phenotypic characteristics for the differentiation of the isolates from their closest phylogenetic neighbours are production of acid from amygdalin and utilization of adonitol and sorbitol. A novel species, Pantoea allii sp. nov., is proposed, with type strain BD 390(T) ( = LMG 24248(T)).

  4. Role of Endogenous Plant Growth Regulators in Seed Dormancy of Avena fatua

    Science.gov (United States)

    Metzger, James D.

    1983-01-01

    Gibberellin A1 (GA1) was identified by combined gas chromatographymass spectrometry as the major biologically active gibberellin (GA) in seeds of wild oat (Avena fatua L.) regardless of the depth of dormany or stage of imbibition. Both unimbibed dormant and nondromant seeds contained similar amounts of GA1 as estimated by the d5-maize bioassay. During imbibition, the level of GA1 declined in both dormant and non-dormant seeds, although the decline was more rapid in dormant seeds. Only in imbibing nondormant seeds did the GA biosynthesis inhibitor, 2-chloroethyltrimethyl ammonium chloride (CCC), cause a reduction in the level of GA1 from that observed in control seeds. These results are interpreted as an indication that while afterripening does not cause a direct change in the levels of GAs during dry storage, it does induce a greater capacity for GA biosynthesis during imbibition. Nondormant seeds imbibed in the presence of 50 millimolar CCC germinated equally as well as untreated seeds. When wild oat plants were fed CCC throughout the entire life cycle, viable seeds were produced that lacked detectable GA-like substances. These seeds afterripened at a slightly slower rate than the controls. Moreover, completely afterripened (nondormant) seeds from plants fed CCC continuously contained no detectable GA-like substances, and when these seeds germinated, dwarf seedlings were produced, indicating GA biosynthesis was inhibited during and after germination. In total, these results suggest that the increased capacity for GA biosynthesis observed in imbibing nondormant seeds is not a necessary prerequisite for germination. It is therefore possible that GA biosynthesis in imbibing nondormant seeds is one of many coordinated biochemical events that occur during germination rather than an initiator of the processes leading to germination. PMID:16663302

  5. SeedUSoon: A New Software Program to Improve Seed Stock Management and Plant Line Exchanges between Research Laboratories.

    Science.gov (United States)

    Charavay, Céline; Segard, Stéphane; Pochon, Nathalie; Nussaume, Laurent; Javot, Hélène

    2017-01-01

    Plant research is supported by an ever-growing collection of mutant or transgenic lines. In the past, a typical basic research laboratory would focus on only a few plant lines that were carefully isolated from collections of lines containing random mutations. The subsequent technological breakthrough in high-throughput sequencing, combined with novel and highly efficient mutagenesis techniques (including site-directed mutagenesis), has led to a recent exponential growth in plant line collections used by individual researchers. Tracking the generation and genetic properties of these genetic resources is thus becoming increasingly challenging for researchers. Another difficulty for researchers is controlling the use of seeds protected by a Material Transfer Agreement, as often only the original recipient of the seeds is aware of the existence of such documents. This situation can thus lead to difficult legal situations. Simultaneously, various institutions and the general public now demand more information about the use of genetically modified organisms (GMOs). In response, researchers are seeking new database solutions to address the triple challenge of research competition, legal constraints, and institutional/public demands. To help plant biology laboratories organize, describe, store, trace, and distribute their seeds, we have developed the new program SeedUSoon, with simplicity in mind. This software contains data management functions that allow the separate tracking of distinct mutations, even in successive crossings or mutagenesis. SeedUSoon reflects the biotechnological diversity of mutations and transgenes contained in any specific line, and the history of their inheritance. It can facilitate GMO certification procedures by distinguishing mutations on the basis of the presence/absence of a transgene, and by recording the technology used for their generation. Its interface can be customized to match the context and rules of any laboratory. In addition, Seed

  6. SeedUSoon: A New Software Program to Improve Seed Stock Management and Plant Line Exchanges between Research Laboratories

    Science.gov (United States)

    Charavay, Céline; Segard, Stéphane; Pochon, Nathalie; Nussaume, Laurent; Javot, Hélène

    2017-01-01

    Plant research is supported by an ever-growing collection of mutant or transgenic lines. In the past, a typical basic research laboratory would focus on only a few plant lines that were carefully isolated from collections of lines containing random mutations. The subsequent technological breakthrough in high-throughput sequencing, combined with novel and highly efficient mutagenesis techniques (including site-directed mutagenesis), has led to a recent exponential growth in plant line collections used by individual researchers. Tracking the generation and genetic properties of these genetic resources is thus becoming increasingly challenging for researchers. Another difficulty for researchers is controlling the use of seeds protected by a Material Transfer Agreement, as often only the original recipient of the seeds is aware of the existence of such documents. This situation can thus lead to difficult legal situations. Simultaneously, various institutions and the general public now demand more information about the use of genetically modified organisms (GMOs). In response, researchers are seeking new database solutions to address the triple challenge of research competition, legal constraints, and institutional/public demands. To help plant biology laboratories organize, describe, store, trace, and distribute their seeds, we have developed the new program SeedUSoon, with simplicity in mind. This software contains data management functions that allow the separate tracking of distinct mutations, even in successive crossings or mutagenesis. SeedUSoon reflects the biotechnological diversity of mutations and transgenes contained in any specific line, and the history of their inheritance. It can facilitate GMO certification procedures by distinguishing mutations on the basis of the presence/absence of a transgene, and by recording the technology used for their generation. Its interface can be customized to match the context and rules of any laboratory. In addition, Seed

  7. Assessing the impacts of nonrandom seed dispersal by multiple frugivore partners on plant recruitment.

    Science.gov (United States)

    Razafindratsima, Onja H; Dunham, Amy E

    2015-01-01

    Directed dispersal is defined as enhanced dispersal of seeds into suitable microhabitats, resulting in higher recruitment than if seeds were dispersed randomly. While this constitutes one of the main explanations for the adaptive value of frugivore-mediated seed dispersal, the generality of this advantage has received little study, particularly when multiple dispersers are involved. We used probability recruitment models of a long-lived rainforest tree in Madagascar to compare recruitment success under dispersal by multiple frugivores, no dispersal, and random dispersal. Models were parameterized using a three-year recruitment experiment and observational data of dispersal events by three frugivorous lemur species that commonly disperse its seeds. Frugivore-mediated seed dispersal was nonrandom with respect to canopy cover and increased modeled per-seed sapling recruitment fourfold compared to no dispersal. Seeds dispersed by one frugivore, Eulemur rubriventer, had higher modeled recruitment probability than seeds dispersed randomly. However, as a group, our models suggest that seeds dispersed by lemurs would have lower recruitment than if dispersal were random. Results demonstrate the importance of evaluating the contribution of multiple frugivores to plant recruitment for understanding plant population dynamics and the ecological and evolutionary significance of seed dispersal.

  8. Fantasy Seed Company: A Role Playing Game for Plant Breeding Courses

    Science.gov (United States)

    Hague, Steve S.

    2011-01-01

    Understanding plant breeding as well as procedures and issues of seed companies are skills students studying agronomy need to acquire. Simulation games can be effective teaching tools in developing higher-order thinking skills of students. The "Fantasy Seed Company" game was developed to create motivated learners by allowing students to run a mock…

  9. Does an ant-dispersed plant, Viola reichenbachiana, suffer from reduced seed dispersal under inundation disturbances?

    NARCIS (Netherlands)

    Prinzing, A.; Dauber, J.; Hammer, E.; Hammouti, N.; Bohning-Gaese, K.

    2008-01-01

    Many plant species use ants as seed dispersers. This dispersal mode is considered to be susceptible to disturbances, but the effect of natural, small-scale disturbances is still unknown. We investigated how small-scale disturbances due to inundation affect seed dispersal in Viola reichenbachiana, a

  10. Fantasy Seed Company: A Role Playing Game for Plant Breeding Courses

    Science.gov (United States)

    Hague, Steve S.

    2011-01-01

    Understanding plant breeding as well as procedures and issues of seed companies are skills students studying agronomy need to acquire. Simulation games can be effective teaching tools in developing higher-order thinking skills of students. The "Fantasy Seed Company" game was developed to create motivated learners by allowing students to run a mock…

  11. High-throughput culturing of fungi from plant litter by a dilution-to-extinction technique.

    Science.gov (United States)

    Collado, Javier; Platas, Gonzalo; Paulus, Barbara; Bills, Gerald F

    2007-06-01

    High-throughput bacterial cultivation has improved the recovery of slow-growing and previously uncultured bacteria. The most robust high-throughput methods are based on techniques of 'dilution to extinction' or 'extinction culturing'. The low-density partitioning of CFUs in tubes or microwells exploits the fact that the number of culturable species typically increases as inoculum density decreases. Bacterial high-throughput culturing methods were adapted to fungi to generate large numbers of fungal extinction cultures. The efficiency of extinction culturing was assessed by comparing it with particle filtration and automated plate-streaking. Equal volumes of particle suspension from five litter collections of the New Zealand forest tree Elaeocarpus dentatus were compared. Dilute particle suspensions of litter were pipetted into 48-well tissue culture plates containing 1 mL of agar medium per well. Particle volumes from the same samples were applied to continuous agar surfaces in Omnitray plates by automated streaking, and fungal diversity and richness were measured. The spectrum of isolates was assessed by microscopy and sequencing of the ITS or 28S region of the rRNA gene. Estimates of species diversity between the two methods were comparable, but extinction culturing increased species richness. Compared with plating methods using continuous surfaces, extinction culturing distributes fungal propagules over partitioned surfaces. Intercolony interactions are reduced, permitting longer incubation times, and colony initiation and recovery improved. Effort to evaluate and recover colonies from fungal isolation plates was substantially reduced.

  12. Plant growth regulation in seed crops of perennial ryegrass (Lolium perenne L)

    DEFF Research Database (Denmark)

    Boelt, Birte; Lemaire, Charles; Abel, Simon;

    2016-01-01

    Seed yield components were recorded in plants of perennial ryegrass cv. Calibra a medium late, forage type (4n) in a two factorial block design with Nitrogen (N) and plant growth regulator (PGR) application in 2014 and 2015 at Aarhus University (AU), Flakkebjerg. For each plant, reproductive...

  13. Response of SC704 maize hybrid seed production to planting pattern

    African Journals Online (AJOL)

    Mohammed Reza

    2012-05-08

    May 8, 2012 ... 1Safiabad Research Center, Dezful, Iran. 2Department of ... Key words: Planting pattern, seed produce, corn grain, S.C.704 hybrid. INTRODUCTION ... plants for light, moisture and food would decrease and plants will have a ...

  14. Soil Seed Bank and Plant Community Development in Passive Restoration of Degraded Sandy Grasslands

    Directory of Open Access Journals (Sweden)

    Renhui Miao

    2016-06-01

    Full Text Available To evaluate the efficacy of passive restoration on soil seed bank and vegetation recovery, we measured the species composition and density of the soil seed bank, as well as the species composition, density, coverage, and height of the extant vegetation in sites passively restored for 0, 4, 7, and 12 years (S0, S4, S7, and S12 in a degraded grassland in desert land. Compared with S0, three more species in the soil seed bank at depths of 0–30 cm and one more plant species in the community was detected in S12. Seed density within the topsoil (0–5 cm was five times higher in S12 than that in S0. Plant densities in S7 and S12 were triple and quadruple than that in S0. Plant coverage was increased by 1.5 times (S4, double (S7, and triple (S12 compared with S0. Sørensen’s index of similarity in species composition between the soil seed bank and the plant community were high (0.43–0.63, but it was lower in short-term restoration sites (S4 and S7 than that in no and long-term restoration sites (S0 and S12. The soil seed bank recovered more slowly than the plant community under passive restoration. Passive restoration is a useful method to recover the soil seed bank and vegetation in degraded grasslands.

  15. Evolution of the APETALA2 Gene Lineage in Seed Plants.

    Science.gov (United States)

    Zumajo-Cardona, Cecilia; Pabón-Mora, Natalia

    2016-07-01

    Gene duplication is a fundamental source of functional evolutionary change and has been associated with organismal diversification and the acquisition of novel features. The APETALA2/ETHYLENE RESPONSIVE ELEMENT-BINDING FACTOR (AP2/ERF) genes are exclusive to vascular plants and have been classified into the AP2-like and ERF-like clades. The AP2-like clade includes the AINTEGUMENTA (ANT) and the euAPETALA2 (euAP2) genes, both regulated by miR172 Arabidopsis has two paralogs in the euAP2 clade, namely APETALA2 (AP2) and TARGET OF EAT3 (TOE3) that control flowering time, meristem determinacy, sepal and petal identity and fruit development. euAP2 genes are likely functionally divergent outside Brassicaceae, as they control fruit development in tomato, and regulate inflorescence meristematic activity in maize. We studied the evolution and expression patterns of euAP2/TOE3 genes to assess large scale and local duplications and evaluate protein motifs likely related with functional changes across seed plants. We sampled euAP2/TOE3 genes from vascular plants and have found three major duplications and a few taxon-specific duplications. Here, we report conserved and new motifs across euAP2/TOE3 proteins and conclude that proteins predating the Brassicaceae duplication are more similar to AP2 than TOE3. Expression data show a shift from restricted expression in leaves, carpels, and fruits in non-core eudicots and asterids to a broader expression of euAP2 genes in leaves, all floral organs and fruits in rosids. Altogether, our data show a functional trend where the canonical A-function (sepal and petal identity) is exclusive to Brassicaceae and it is likely not maintained outside of rosids. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Implications of nonrandom seed abscission and global stilling for migration of wind-dispersed plant species.

    Science.gov (United States)

    Thompson, Sally E; Katul, Gabriel G

    2013-06-01

    Migration of plant populations is a potential survival response to climate change that depends critically on seed dispersal. Biological and physical factors determine dispersal and migration of wind-dispersed species. Recent field and wind tunnel studies demonstrate biological adaptations that bias seed release toward conditions of higher wind velocity, promoting longer dispersal distances and faster migration. However, another suite of international studies also recently highlighted a global decrease in near-surface wind speeds, or 'global stilling'. This study assessed the implications of both factors on potential plant population migration rates, using a mechanistic modeling framework. Nonrandom abscission was investigated using models of three seed release mechanisms: (i) a simple drag model; (ii) a seed deflection model; and (iii) a 'wear and tear' model. The models generated a single functional relationship between the frequency of seed release and statistics of the near-surface wind environment, independent of the abscission mechanism. An Inertial-Particle, Coupled Eulerian-Lagrangian Closure model (IP-CELC) was used to investigate abscission effects on seed dispersal kernels and plant population migration rates under contemporary and potential future wind conditions (based on reported global stilling trends). The results confirm that nonrandom seed abscission increased dispersal distances, particularly for light seeds. The increases were mitigated by two physical feedbacks: (i) although nonrandom abscission increased the initial acceleration of seeds from rest, the sensitivity of the seed dispersal to this initial condition declined as the wind speed increased; and (ii) while nonrandom abscission increased the mean dispersal length, it reduced the kurtosis of seasonal dispersal kernels, and thus the chance of long-distance dispersal. Wind stilling greatly reduced the modeled migration rates under biased seed release conditions. Thus, species that require

  17. Soil moisture and fungi affect seed survival in California grassland annual plants.

    Directory of Open Access Journals (Sweden)

    Erin A Mordecai

    Full Text Available Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season than in the summer (dry season, but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

  18. Soil moisture and fungi affect seed survival in California grassland annual plants.

    Science.gov (United States)

    Mordecai, Erin A

    2012-01-01

    Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season) than in the summer (dry season), but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

  19. How Does Your Garden Grow? Early Conceptualization of Seeds and Their Place in the Plant Growth Cycle.

    Science.gov (United States)

    Hickling, Anne K.; Gelman, Susan A.

    1995-01-01

    Examined young children's understanding of seed origins and growth preconditions and the stages of plant growth. Found that, by 4.5 years, children realized that natural causal mechanisms underlie plant growth and appreciated the relationship of seeds to plants. Results suggest that preschoolers hold theory-like understandings of plants similar to…

  20. Patterns of synonymous codon usage bias in chloroplast genomes of seed plants

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Codon usage in chloroplast genome of six seed plants (Arabidopsis thaliana, Populus alba, Zea mays, Triticum aestivum,Pinus koraiensis and Cycas taitungensis) was analyzed to find general patterns of codon usage in chloroplast genomes of seed plants.The results show that chloroplast genomes of the six seed plants had similar codon usage patterns, with a strong bias towards a high representation of NNA and NNT codons. In chloroplast genomes of the six seed plants, the effective number of codons (ENC) for most genes was similar to that of the expected ENC based on the GC content at the third codon position, but several genes with low ENC values were laying below the expected curve. All of these data indicate that codon usage was dominated by a mutational bias in chloroplast genomes of seed plants and that selection appeared to be limited to a subset of genes and to only subtly affect codon us-age. Meantime, four, six, eight, nine, ten and 12 codons were defined as the optimal codons in chloroplast genomes of the six seed plants.

  1. MYCOFLORA ASSOCIATED WITH SOME STORED SEEDS AND THEIR CONTROL BY AQUEOUS EXTRACT FROM MEDICINAL PLANTS

    Directory of Open Access Journals (Sweden)

    ZAKARIA A. M. BAKA*, MAMDOUH S. SERAG AND TAREK A. KARDOSHA

    2014-10-01

    This study aimed to isolate and identify seed-borne fungi associated with some seeds collected from Egypt markets during storage and the possibility of their control by medicinal plant extracts. The studied seeds were Sorghum bicolor, Triticum aestivum, Oryza sativa, Lens esculentus, Vigna sinensis, Arachis hypogea and Vicia faba. Thirteen fungal species were isolated from those Aspergillus niger, A. flavus and Penicillium chrysogenum were the most prevalent. Sixteen medicinal plants named Allium sativum, Aloe vera, Mentha basilicum, Musa acuminate, Eucalptus rostrata, Datura stramonium, Zingiber officinale, Azadirachta indica, Jatropha curcas, Euphorbia peplis, Ocimum basilicum, Carum carvi, Rosmarinus officinalis, Nigella sativa, Cuminum cyminum and Citrullus colocynthis were screened for their antifungal activities. Aqueous plant extracts of all mentioned plants were tested against the most prodomonant fungal species. Allium sativum, Zingiber officinale, Datura stramonium and Citrullus colocynthis exhibited the highest antifungal activity within all plants tested. Treated seeds by plant extracts showed an increase of the percentage of their germination and reduction of seed-borne fungal infection. Mycotoxins of infected seeds and fungal pathogens were also determined.

  2. Nickel translocation from seed during germination and growth of young maize plants

    OpenAIRE

    Doroghazi Oto T.; Kastori Rudolf R.; Maksimović Ivana V.

    2010-01-01

    Effect of different concentrations of nickel (0, 10-5, 10-4, 10-3 and 10-2 mol Ni/dm3) present at the time of maize seed imbibition, on concentration, distribution and nickel accumulation coefficient in the root and the shoot, biological value of the seed and growth of young plants was investigated. It was found that during germination the nickel from the seed is intensively translocated to the root and shoot of young plants. With increase of applied concentrations of nickel, its concen...

  3. Soil seed banks confer resilience to savanna grass-layer plants during seasonal disturbance

    Science.gov (United States)

    Scott, Kenneth; Setterfield, Samantha; Douglas, Michael; Andersen, Alan

    2010-03-01

    An understanding of soil seed bank processes is crucial for understanding vegetation dynamics, particularly in ecosystems experiencing frequent disturbance. This paper examines seed bank dynamics in a tropical savanna in northern Australia, an environment characterised by frequent fire and highly seasonal rainfall. In particular, we examine the contribution of seed bank processes to the high level of resilience shown by grass-layer vegetation in relation to fire. We assess the spatial congruence between seed bank composition and extant vegetation, document temporal variation in the germinable seed bank over the annual dry season, test the effects of laboratory-applied heat and smoke treatments on seed germinability, and determine the effect of experimental fires on seed bank composition. Although dominant species were shared, the composition of the germinable seed bank was significantly different to that of extant vegetation, with approximately half the extant species not being detected in the seed bank. The density and species richness of germinable seeds was significantly greater in the late dry season than the early dry season, with annual grasses showing particularly high levels of seed dormancy in the early dry season. The density and species richness of germinable seeds in the seed bank was significantly enhanced by laboratory-applied treatments of smoke and especially heat, driven by the response of legumes. However, fire had no significant effect on the density or species richness of germinable seeds in the field, indicating soil temperatures during fire were too low to overcome physical dormancy, or burial was too deep to experience adequate heating or smoke exposure. Our results provide a mechanistic understanding of the persistence of annual grasses and forbs in an environment subject to frequent fire and highly seasonal rainfall, and, together with the sprouting capacity of perennial grasses, explain the high resilience of savanna grass-layer plants in

  4. Fatty acids and sterols composition, and antioxidant activity of oils extracted from plant seeds.

    Science.gov (United States)

    Kozłowska, Mariola; Gruczyńska, Eliza; Ścibisz, Iwona; Rudzińska, Magdalena

    2016-12-15

    This study determined and compared the contents of bioactive components in plant seed oils extracted with n-hexane (Soxhlet method) and chloroform/methanol (Folch method) from coriander, caraway, anise, nutmeg and white mustard seeds. Oleic acid dominated among unsaturated fatty acids in nutmeg and anise seed oils while petroselinic acid was present in coriander and caraway oils. Concerning sterols, β-sitosterol was the main component in seed oils extracted with both methods. The content of total phenolics in nutmeg, white mustard and coriander seed oils extracted with chloroform/methanol was higher than in their counterparts prepared with n-hexane. The seed oil samples extracted according to the Folch method exhibited a higher ability to scavenge DPPH radicals compared to the oil samples prepared with the Soxhlet method. DPPH values of the methanolic extracts derived from oils produced with the Folch method were also higher than in the oils extracted with n-hexane.

  5. Using composting for control seed germination of invasive plant (water hyacinth) in Extremadura (Spain)

    Science.gov (United States)

    Labrador, Juana; Gordillo, Judit; Ruiz, Trinidad; Albano, Eva; Moreno, Marta M.

    2016-04-01

    The biotransformation of the invasive water hyacinth (Eichhornia crassipes) by composting has been showed as a viable alternative to offset the economic cost of eliminating an invasive plant giving a value to the by-product; however, as result of the propagative plant capacity, it was necessary to check if the composting process could eliminate the germination seed rate. Despite the high temperatures and the biochemical biotransformation processes of the composting components, in the case of seed water hyacinth, with a recovery rate of 100%, damage was observed in some parts of the seed anatomy such as in the outer teguments; however, other parts of the seed coat and the endosperm maintained their integrity. A microscopic analysis revealed that the embryo was noticeable and this was supported by the rate of seed germination observed (3.5 ± 0.96%). The results indicate that the use of water hyacinth for compost production is not completely safe from an environmental perspective. Keywords: Eichhornia crassipes, water hyacinth, invasive plant, seed anatomy, seed germination rate, compost. References: Ruiz T., Martín de Rodrigo E., Lorenzo G., Albano E., Morán R., Sánchez J.M. 2008. The Water Hyacinth, Eichhornia crassipes: an invasive plant in the Guadiana River Basin (Spain). Aquatic Invasions Volume 3, Issue 1:42-53.

  6. The Importance of Seed Characteristics in the Dispersal of Splash-Cup Plants

    Science.gov (United States)

    Eklof, Joel; Pepper, Rachel Pepper; Echternach, Juliana

    2016-11-01

    Splash-cup plants disperse their seeds by exploiting the kinetic energy of raindrops. When raindrops impact the splash-cup, a 3-5 mm vessel that holds seeds, the seeds are projected up to 1 m away from the parent plant. It has been established, using 3D printed models, that a 40°cone angle maximizes dispersal distance when seeds are not present in the cup. We therefore use 40°cups with the addition of different types of seeds to determine the effect that seeds of varying characteristics have on the dispersal and splash dynamics of splash-cup plants. Splash characteristics and dispersal distances of seeds with differing characteristics such as size, shape, texture, density, and hydrophobicity were compared to one another, as well as to the case of having no seeds present. We found that the presence of seeds dramatically decreased dispersal distance and changed splash characteristics (are measured by the angle and velocity of the resulting splash). In addition, different types of seeds yielded splashes with differing dispersal distance and splash characteristics. Splash characteristics and dispersal distances of glass beads of differing hydrophobicity were compared to determine the effect hydrophobicity has on dispersal and splash dynamics. These beads yielded some differences in dispersal distance, but no notable difference in splash dynamics. Models of the conical fruit bodies of the splash-cups were 3D printed and high-speed video was used to find splash characteristics, and dispersal distance was calculated by measuring the distance from the model to the final resting position of the seeds and droplets.

  7. When will plant morphology affect the shape of a seed dispersal "kernel"?

    Science.gov (United States)

    Cousens, R D; Rawlinson, A A

    2001-08-07

    Most models of dispersal assume that plants are point sources. In reality, the scale in height over which seed sources are distributed is often of the same order as the scale in distance over which most individual seeds are dispersed. But is this sufficient to affect the fundamental shapes of dispersal frequency distributions? Most published conclusions about the effects of canopy structure on dispersal are subjective. A model is developed to explore the consequences of plant canopies for the shapes of whole-plant seed dispersal "kernels". The canopies were described by simple geometric shapes, while an empirical probability density function (PDF) was used for dispersal from a point source. It was found that the resulting whole-plant PDF for dispersal distance was almost invariably peaked, whereas the PDF for the density of seed rain (as would be measured by pitfall traps) could either be peaked or monotonic according to the canopy shape, position of seeds in the canopy, and mean dispersal distance. The shapes of kernels from whole plants (distributed seed sources) can be very different from those derived from a point source under certain circumstances. Copyright 2001 Academic Press.

  8. Dynamics of seed-borne rice endophytes on early plant growth stages.

    Directory of Open Access Journals (Sweden)

    Pablo R Hardoim

    Full Text Available Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed.

  9. Pre-sowing magnetic treatments of tomato seeds increase the growth and yield of plants.

    Science.gov (United States)

    De Souza, A; Garcí, D; Sueiro, L; Gilart, F; Porras, E; Licea, L

    2006-05-01

    The effects of pre-sowing magnetic treatments on growth and yield of tomato (cv Campbell-28) were investigated under field conditions. Tomato seeds were exposed to full-wave rectified sinusoidal non-uniform magnetic fields (MFs) induced by an electromagnet at 100 mT (rms) for 10 min and at 170 mT (rms) for 3 min. Non-treated seeds were considered as controls. Plants were grown in experimental plots (30.2 m(2)) and were cultivated according to standard agricultural practices. During the vegetative and generative growth stages, samples were collected at regular intervals for growth rate analyses, and the resistance of plants to geminivirus and early blight was evaluated. At physiological maturity, the plants were harvested from each plot and the yield and yield parameters were determined. In the vegetative stage, the treatments led to a significant increase in leaf area, leaf dry weight, and specific leaf area (SLA) per plant. Also, the leaf, stem, and root relative growth rates of plants derived from magnetically treated seeds were greater than those shown by the control plants. In the generative stage, leaf area per plant and relative growth rates of fruits from plants from magnetically exposed seeds were greater than those of the control plant fruits. At fruit maturity stage, all magnetic treatments increased significantly (P magnetically treated seeds than that of the controls. A significant delay in the appearance of first symptoms of geminivirus and early blight and a reduced infection rate of early blight were observed in the plants from exposed seeds to MFs. Pre-sowing magnetic treatments would enhance the growth and yield of tomato crop.

  10. Viability of various weed seeds in anaerobic conditions (biogas plant)

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, S.; Hansen, J.

    1983-04-01

    Seeds from different weeds, Urtica urens L. (nettle), Solanum nigrum L. (nightshade), Avena fatua L. (wild oat-grass), Brassica napus L. (rape), Chenopodium album L. (goose-foot), were put into small polyester net bags, which were placed in biogas reactors containing cattle manure. These ''biogas reactors'' were placed at different temperatures . Net bags were taken out after 4.5, 10.5, 21.5, 38 and 53 days, and the seeds were tested for their viability by germination tests and the tetrazolium method. Concerning all seeds it was manifested that the viability decreased very steeply at 35degC. Most of the seeds had a T/sub 50/ at 2-5 days; Chenopodium album L seeds had a T/sub 50/ at 16 days. After 4.5 days it was not possible to find living Avena fatua L seeds. The decrease in viability was less steep at 20degC and even less steep at 2degC.

  11. Does spatial arrangement of 3D plants affect light transmission and extinction coefficient within maize crops?

    Science.gov (United States)

    Row spacing effects on light interception and extinction coefficient have been inconsistent for maize (Zea mays L.) when calculated with field measurements. To avoid inconsistencies due to variable light conditions and variable leaf canopies, we used a model to describe three-dimensional (3D) shoot ...

  12. Mother-plant-mediated pumping of zinc into the developing seed.

    Science.gov (United States)

    Olsen, Lene Irene; Hansen, Thomas H; Larue, Camille; Østerberg, Jeppe Thulin; Hoffmann, Robert D; Liesche, Johannes; Krämer, Ute; Surblé, Suzy; Cadarsi, Stéphanie; Samson, Vallerie Ann; Grolimund, Daniel; Husted, Søren; Palmgren, Michael

    2016-01-01

    Insufficient intake of zinc and iron from a cereal-based diet is one of the causes of 'hidden hunger' (micronutrient deficiency), which affects some two billion people(1,2). Identifying a limiting factor in the molecular mechanism of zinc loading into seeds is an important step towards determining the genetic basis for variation of grain micronutrient content and developing breeding strategies to improve this trait(3). Nutrients are translocated to developing seeds at a rate that is regulated by transport processes in source leaves, in the phloem vascular pathway, and at seed sinks. Nutrients are released from a symplasmic maternal seed domain into the seed apoplasm surrounding the endosperm and embryo by poorly understood membrane transport processes(4-6). Plants are unique among eukaryotes in having specific P1B-ATPase pumps for the cellular export of zinc(7). In Arabidopsis, we show that two zinc transporting P1B-ATPases actively export zinc from the mother plant to the filial tissues. Mutant plants that lack both zinc pumps accumulate zinc in the seed coat and consequently have vastly reduced amounts of zinc inside the seed. Blockage of zinc transport was observed at both high and low external zinc supplies. The phenotype was determined by the mother plant and is thus due to a lack of zinc pump activity in the seed coat and not in the filial tissues. The finding that P1B-ATPases are one of the limiting factors controlling the amount of zinc inside a seed is an important step towards combating nutritional zinc deficiency worldwide.

  13. Seed size-number trade-off in Euterpe edulis in plant communities of the Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Santin Brancalion

    2014-06-01

    Full Text Available Investigations of seed size and number differences among plant populations growing in contrasting habitats can provide relevant information about ecological strategies that optimize reproductive effort. This may imply important consequences for biodiversity conservation and restoration. Therefore, we sought to investigate seed size-number trade-off in Euterpe edulis populations growing in plant communities in the Brazilian Atlantic Forest. Seed dry mass and seed number per bunch were evaluated in 2008 and 2009 in large remnants of the Seasonally Dry Forest, Restinga Forest and Atlantic Rainforest in southeastern Brazil, in 20 individuals per site and year. Seed size and seed number varied among forest types, but a seed size-number trade-off was neither observed within nor among populations. Positive association between seed size and number was found in the Atlantic Rainforest, and reduced seed crop was not accompanied by heavier seeds in the Restinga Forest. Seed dry mass declined in 2009 in all three forest types. Compared to seed number in 2008, palms of both the Restinga Forest and the Atlantic Rainforest produced in 2009 higher yields of smaller seeds - evidence of between years seed size-number trade-off -, while the Seasonally Dry Forest population produced a reduced number of smaller seeds. Such a flexible reproductive strategy, involving neutral, positive, and negative associations between seed size and number could enhance the ecological amplitude of this species and their potential to adapt to different environment conditions.

  14. 植物遗传资源的种子基因库保存%Ex Situ Conservation of Plant Genetic Resources through Seed-Gene Bank

    Institute of Scientific and Technical Information of China (English)

    唐安军; 宋松泉; 龙春林

    2007-01-01

    一个物种的灭绝是与其受生物因子和非生物因子的威胁程度相关的.随着物种的加速绝灭,保护生物多样性受到广泛地关注.保护生物多样性的最有效的生物技术之一是建立种子基因库,进行迁地保护.种子库理想的贮藏条件主要取决于种子含水量、贮藏环境(如温度和湿度)和贮存种子的容器.进行种子贮藏,了解种子生命力和活力的影响因子的作用机理是十分重要和必要的.除了种子自身的生理特征外,种子的贮藏寿命与种子成熟度、收获技术、加工处理方法也是息息相关的.即使在最适的库存条件下,种子也会随时间发生劣变.因此,必须根据种子特定的贮藏行为,加以考虑影响种子存活的3个主要方面(贮藏环境、贮藏期和植物种类)而选择有效的贮藏方案.本文试图讨论种子贮藏生理的几个重要方面及其需解决的技术问题,以便更好地通过种子基因库,长期有效地保存植物种质资源.%With the acceleration of extinction of species,biodiversity conservation is extensively concerned.The extinction of species is concerned with the degree of threat by biotic and abiotic factors.So,taking action to preserve plant species is very necessary and paramount before their extinction.One of the most effective biological techniques to conserve the biodiversity is the establishment of genebanks,i.e.ex situ conservation.The elucidation of various factors that regulate seed viability and vigor in storage is essential.An ideal condition to prolong the longevity is mainly depended on seed water content,temperature,humidity and types of containers used during storage.The optimum stage of seed maturity,harvesting techniques and processing,in addition to physiological features such as degree of dormancy,also play key roles in seed storage.Certainly,desiccated seeds deteriorate with time even under extremely good genebanking conditions.According to seed storage

  15. [Relationships between seed size and seedling growth strategy of herbaceous plant: a review].

    Science.gov (United States)

    Wu, Gao-lin; Du, Guo-zhen

    2008-01-01

    Seed size and seedling recruitment strategy are of importance in the life-history strategy of plant. In this paper, the current ecological researches at home and aboard on the relationships between seed size and seedling growth were reviewed from the aspects of the effects of seed size on seed germination and seedling emergence, the relationships between seed size and seedling growth traits, and the relationships between seed size and seedling survival and competition ability. Some suggestions on future researches in this field were put forward. There were likely different relationships between seed size and seedling growth in different microenvironments and vegetation types, and the effects of seed size on seedling growth could result in different contributions of different seed-size species to the seedling recruitment of vegetation. The large-scale community level and the small-scale intra- and inter-species level researches on this issue should be strengthened, which would have significance for the recruitment and renewing of natural vegetation.

  16. Plant Response to TSWV and Seed Accumulation of Resveratrol in Peanut

    Science.gov (United States)

    Biotic and abiotic stress may induce peanut plants to produce a high amount of resveratrol. The relationship of plant response to tomato spotted wilt virus (TSWV) and seed accumulation of resveratrol was investigated. Twenty peanut accessions and six wild relatives were selected from the US peanut g...

  17. Effects of Autumn and Spring Heat Waves on Seed Germination of High Mountain Plants.

    Science.gov (United States)

    Orsenigo, Simone; Abeli, Thomas; Rossi, Graziano; Bonasoni, Paolo; Pasquaretta, Cristian; Gandini, Maurizia; Mondoni, Andrea

    2015-01-01

    Alpine plants are considered to be particularly vulnerable to climate change and related extreme episodes, such as heat waves. Despite growing interest in the impact of heat waves on alpine plants, knowledge about their effects on regeneration is still fragmentary. Recruitment from seeds will be crucial for the successful migration and survival of these species and will play a key role in their future adaptation to climate change. In this study, we assessed the impacts of heat waves on the seed germination of 53 high mountain plants from the Northern Apennines (Italy). The seeds were exposed to laboratory simulations of three seasonal temperature treatments, derived from real data recorded at a meteorological station near the species growing site, which included two heat wave episodes that occurred both in spring 2003 and in autumn 2011. Moreover, to consider the effect of increasing drought conditions related to heat waves, seed germination was also investigated under four different water potentials. In the absence of heat waves, seed germination mainly occurred in spring, after seeds had experienced autumn and winter seasons. However, heat waves resulted in a significant increase of spring germination in c. 30% of the species and elicited autumn germination in 50%. When heat waves were coupled with drought, seed germination decreased in all species, but did not stop completely. Our results suggest that in the future, heat waves will affect the germination phenology of alpine plants, especially conditionally dormant and strictly cold-adapted chorotypes, by shifting the emergence time from spring to autumn and by increasing the proportion of emerged seedlings. The detrimental effects of heat waves on recruitment success is less likely to be due to the inhibition of seed germination per se, but rather due to seedling survival in seasons, and temperature and water conditions that they are not used to experiencing. Changes in the proportion and timing of emergence

  18. Lignification of the plant and seed quality of RR soybeans sprayed with herbicide glyphosate

    Directory of Open Access Journals (Sweden)

    Cristiane Fortes Gris

    2013-04-01

    Full Text Available Differences in levels of lignin in the plant between conventional and transgenic cultivars RR has been reported by several authors, however, there are few studies evaluating the influence of spraying of glyphosate on the lignin in the plant and RR soybean seeds. The aim of this study was to evaluate the physiological quality of RR transgenic soybean seeds and the lignin contents of plants sprayed with the herbicide glyphosate. The assays were conducted both in greenhouse and field in the municipality of Lavras, MG, in the agricultural year 2007/08. The experiment was arranged in a splitplot design with four replicates, considering the treatments hand weeding and herbicide glyphosate as plots, and five RR soybean cultivars (BRS 245 RR, BRS 247 RR, Valiosa RR, Silvânia RR and Baliza RR as splitplots. In the greenhouse, the cultivars tested were BRS 245 RR and Valiosa RR in a randomized block design with four replicates. The sprayings were carried out at stages V3, V7 and early R5 (3L/ha. The 1000 seed weight, mechanical injury, germination and germination velocity index, emergence velocity index, accelerated aging, electrical conductivity and water soaking seed test, lignin content in the seed coat, in the stem and legumes were determined. The spraying of glyphosate herbicide, in greenhouse and field, did not alter the physiological quality of seeds and the lignin contents in the plant.

  19. Insights into the microstructures of hygroscopic movement in plant seed dispersal.

    Science.gov (United States)

    Elbaum, Rivka; Abraham, Yael

    2014-06-01

    As non-motile organisms, plants develop means to spread their progenies. Hygroscopic movement is a very common mechanism employed in seed dispersal. This type of movement is created when the tissue desiccates and the cell walls dry and shrink. A contraction force develops, the direction and strength of which depends on the architecture of the tissue. This force may be utilized for a simple release of seeds, their catapultion, and for pushing seeds along the soil to a germination locus. We review the formation of a bend, a twist and a coil within various dispersal apparatuses as a reaction to the dehydration of the tissue. We compare the microscopic structures of hygroscopic devices supporting slow or fast movement, adaptations to dry or wet climates, and single use versus repeated movement. We discuss the development of the disconnecting tissues in relation to the development of a hygroscopic mechanism. As plant cultivation is dependent on seed dispersal control, we demonstrate that during the domestication of sesame and wheat, seed dispersal is avoided not due to a defective hygroscopic tissue, but rather a missing dehiscence tissue. Seed dispersal is a crucial stage in the life cycle of plants. Thus, hygroscopic movement plays a central part in plant ecology and agriculture.

  20. Responses of predatory invertebrates to seeding density and plant species richness in experimental tallgrass prairie restorations

    Science.gov (United States)

    Nemec, Kristine T.; Allen, Craig R.; Danielson, Stephen D.; Helzer, Christopher J.

    2014-01-01

    In recent decades, agricultural producers and non-governmental organizations have restored thousands of hectares of former cropland in the central United States with native grasses and forbs. However, the ability of these grassland restorations to attract predatory invertebrates has not been well documented, even though predators provide an important ecosystem service to agricultural producers by naturally regulating herbivores. This study assessed the effects of plant richness and seeding density on the richness and abundance of surface-dwelling (ants, ground beetles, and spiders) and aboveground (ladybird beetles) predatory invertebrates. In the spring of 2006, twenty-four 55 m × 55 m-plots were planted to six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Natural Resources Conservation Service Conservation Reserve Program mix, CP25), at low and high seeding densities. Ants, ground beetles, and spiders were sampled using pitfall traps and ladybird beetles were sampled using sweep netting in 2007–2009. The abundance of ants, ground beetles, and spiders showed no response to seed mix richness or seeding density but there was a significant positive effect of richness on ladybird beetle abundance. Seeding density had a significant positive effect on ground beetle and spider species richness and Shannon–Weaver diversity. These results may be related to differences in the plant species composition and relative amount of grass basal cover among the treatments rather than richness.

  1. A Seed-Based Plant Propagation Algorithm: The Feeding Station Model

    Directory of Open Access Journals (Sweden)

    Muhammad Sulaiman

    2015-01-01

    Full Text Available The seasonal production of fruit and seeds is akin to opening a feeding station, such as a restaurant. Agents coming to feed on the fruit are like customers attending the restaurant; they arrive at a certain rate and get served at a certain rate following some appropriate processes. The same applies to birds and animals visiting and feeding on ripe fruit produced by plants such as the strawberry plant. This phenomenon underpins the seed dispersion of the plants. Modelling it as a queuing process results in a seed-based search/optimisation algorithm. This variant of the Plant Propagation Algorithm is described, analysed, tested on nontrivial problems, and compared with well established algorithms. The results are included.

  2. Single-tube hydroponics as a novel idea for small-scale production of crop seed in a plant incubator.

    Science.gov (United States)

    Kuroda, Masaharu; Ikenaga, Sachiko

    2015-01-01

    We present a novel protocol for small-scale production of crop seed in a plant incubator termed "Single-tube hydroponics." Our protocol minimizes the materials and methods for cultivation whereby a large number of independent plants can be cultured in a limited space. This study may aid in the improvement of crop seed components, especially in the cultivation of transgenic plants.

  3. Effects of mowing date on the opportunities of seed dispersal of ditch bank plant species under different management regimes

    NARCIS (Netherlands)

    Leng, X.; Musters, C.J.M.; Snoo, de G.R.

    2011-01-01

    Mowing and plant removal is a traditional practice in low-intensity farming and likely to lead to high plant species richness. Even today, scientific knowledge on the impact of mowing on seed availability is still very limited. We studied whether the seed availability of ditch bank plant species was

  4. The arbuscular mycorrhizal host status of plant cannot be linked with the Striga seed-germination-activity of plant root exudates

    NARCIS (Netherlands)

    Lendzemo, V.W.; Kuyper, T.W.; Urban, A.; Vegvari, G.; Puschenreiter, M.; Schickmann, S.; Langer, I.; Steinkellner, S.; Vierheilig, H.

    2009-01-01

    Root exudates from sorghum, a Striga and arbuscular mycorrhizal fungal (AMF) host plant, and a number of Striga non-host plants which are AM host or AM non-host plants were collected and their effect on seed germination of Striga hermonthica was tested. Striga seeds germinate exclusively in presence

  5. Breaking of Judas tree seed dormancy by plant hormone treatments

    Directory of Open Access Journals (Sweden)

    Grbić Mihailo

    2014-01-01

    Full Text Available The study deals with the influence of growth regulators on the germination of Judas tree (Cercis siliquastrum L. seed which is double dormant. We simultaneously tested seeds prepared in the conventional procedure: scarification + stratification and scarified seeds treated with phytohormones from the groups of gibberellins, auxin and cytokinins. The results indicate a positive effect of gibberellic acid (GA, as well as some combinations of this phytohormone with others. Recommendations for practice are to combine the conventional procedure with GA. The procedure may shorten the duration of stratification; the application of GA should follow stratification because the temperature of 4°C does not provide growth regulators activity. The study results can serve as the base for easier generative reproduction of this valuable woody ornamental species which could have a wide use in changed climate conditions. [Projekat Ministarstva nauke Republike Srbije, br. 43007: Studying climate change and its influence on the environment: impacts, adaptation and mitigation

  6. Phytotracker, an information management system for easy recording and tracking of plants, seeds and plasmids

    Science.gov (United States)

    2012-01-01

    Background A large number of different plant lines are produced and maintained in a typical plant research laboratory, both as seed stocks and in active growth. These collections need careful and consistent management to track and maintain them properly, and this is a particularly pressing issue in laboratories undertaking research involving genetic manipulation due to regulatory requirements. Researchers and PIs need to access these data and collections, and therefore an easy-to-use plant-oriented laboratory information management system that implements, maintains and displays the information in a simple and visual format would be of great help in both the daily work in the lab and in ensuring regulatory compliance. Results Here, we introduce ‘Phytotracker’, a laboratory management system designed specifically to organise and track plasmids, seeds and growing plants that can be used in mixed platform environments. Phytotracker is designed with simplicity of user operation and ease of installation and management as the major factor, whilst providing tracking tools that cover the full range of activities in molecular genetics labs. It utilises the cross-platform Filemaker relational database, which allows it to be run as a stand-alone or as a server-based networked solution available across all workstations in a lab that can be internet accessible if desired. It can also be readily modified or customised further. Phytotracker provides cataloguing and search functions for plasmids, seed batches, seed stocks and plants growing in pots or trays, and allows tracking of each plant from seed sowing, through harvest to the new seed batch and can print appropriate labels at each stage. The system enters seed information as it is transferred from the previous harvest data, and allows both selfing and hybridization (crossing) to be defined and tracked. Transgenic lines can be linked to their plasmid DNA source. This ease of use and flexibility helps users to reduce their

  7. Allelopathy of the invasive plant Bidens frondosa on the seed germination of Geum japonicum var. chinense.

    Science.gov (United States)

    Wang, X F; Hassani, D; Cheng, Z W; Wang, C Y; Wu, J

    2014-12-12

    Five gradient concentrations (0.02, 0.04, 0.06, 0.08, and 0.10 g/mL) of leaching liquors from the roots, stems, and leaves of the invasive plant Bidens frondosa were used as conditioning fluid to examine its influence on seed germination conditions of the native plant Geum japonicum var. chinense in Huangshan. All leaching liquors of organs suppressed the seed germination of Geum japonicum var. chinense and reduced the final germination percentage and rate, and increased the germination inhibition rate, with a bimodal dependence on concentration. The leaching liquor inhibited the seed germination significantly at the concentration of 0.02 g/mL respectively. The seed germination was also inhibited as the concentration reached to 0.04 g/mL and beyond. Hence the allelopathic effects of the organs were significantly enhanced respectively. This phenomenon represented the presence of allelopathy substances in the root, stem and leaf of Bidens frondosa.

  8. Metabolites change in Jatropha plants due to seed treatment with rhizobacteria and Rhizoctonia bataticola

    Directory of Open Access Journals (Sweden)

    Surender Kumar

    2013-11-01

    Full Text Available An experiment on the metabolite [salicylic acid (SA, jasmonicacid (JA, hydrocyanic acid (HCN and chitinase activity] changes owing to seed treatment with pathogen, plant growth promoting rhizobacteria (PGPRs - (P. maltophilia, P. fluorescens and Bacillus subtilis alone and in combination was conducted at Chaudhary Charan Singh, Haryana Agricultural University, Regional Research Station, Bawal. Jatropha curcas plants raised from root rot pathogen (Rhizoctonia bataticola treated seeds showed an initial increase in SA and hydrocyanic acid HCN content and an opposite trend was observed for JA level and chitinase activity. Though, PGPRs inoculation resulted in higher increase in SA level, JA level and chitinaseactivity in both the cases alone as well as in integration with pathogen, however, maximum increase in JA content was explicited in plants raised after seed treatment with P. fluorescens, the most effective rhizobacteria amongst PGPRs studied. Highest increase in HCN content (45 μg g-1 over control (24 μg g-1 was noticed for P. fluorescens followed by co-seed inoculation with P. fluorescens + pathogen (43 μg g-1 at 10 DPI. The co-seed inoculation elicited 68 units at 10 DPI whereas the pathogen challenged plants showed lower chitinase activity with 42 units. All the metabolites declinedslightly or sharply with age of the plant irrespective of inoculations.

  9. Cosmosperma polyloba gen. et sp. nov., a seed plant from the Upper Devonian of South China

    Science.gov (United States)

    Wang, Deming; Liu, Le; Meng, Meicen; Xue, Jinzhuang; Liu, Tuo; Guo, Yun

    2014-08-01

    Seed plants with ovules were abundant in the Late Devonian of Euramerica and they contribute significantly to our understanding of their early history. However, coeval ovules have been scarce in other regions of the world. Specimens of the seed plant Cosmosperma polyloba gen. et sp. nov. Wang et al. were recently obtained from the Upper Devonian (Famennian) Wutong Formation, at Fanwan Village, Changxing County, Zhejiang Province, China. This new seed plant has cupulate ovules, the uniovulate cupules with up to 16 distal segments and with minute spines on the outer surface, synangiate pollen organs bearing six to eight microsporangia fused only at the base, and planate and highly dissected pinnules in alternate arrangement. It differs from other Devonian seed plants mainly in the organization and position of the uniovulate and ornamented cupule, and in the highly dissected pinnules. Cosmosperma Wang et al. represents the first Devonian ovules recovered from China or eastern Asia and further illustrates the diversity of early spermatophytes. As for the Late Devonian seed plants, it is suggested that the pollen organs are synangiate and simple in organization, and the branches and leaves are generally planate.

  10. Soil warming increases plant species richness but decreases germination from the alpine soil seed bank.

    Science.gov (United States)

    Hoyle, Gemma L; Venn, Susanna E; Steadman, Kathryn J; Good, Roger B; McAuliffe, Edward J; Williams, Emlyn R; Nicotra, Adrienne B

    2013-05-01

    Global warming is occurring more rapidly above the treeline than at lower elevations and alpine areas are predicted to experience above average warming in the future. Temperature is a primary factor in stimulating seed germination and regulating changes in seed dormancy status. Thus, plant regeneration from seed will be crucial to the persistence, migration and post disturbance recruitment of alpine plants in future climates. Here, we present the first assessment of the impact of soil warming on germination from the persistent alpine soil seed bank. Contrary to expectations, soil warming lead to reduced overall germination from the soil seed bank. However, germination response to soil temperature was species specific such that total species richness actually increased by nine with soil warming. We further explored the system by assessing the prevalence of seed dormancy and germination response to soil disturbance, the frequency of which is predicted to increase under climate change. Seeds of a significant proportion of species demonstrated physiological dormancy mechanisms and germination of several species appeared to be intrinsically linked to soil disturbance. In addition, we found no evidence of subalpine species and little evidence of exotic weed species in the soil, suggesting that the soil seed bank will not facilitate their invasion of the alpine zone. In conclusion, changes in recruitment via the alpine soil seed bank can be expected under climate change, as a result of altered dormancy alleviation and germination cues. Furthermore, the alpine soil seed bank, and the species richness therein, has the potential to help maintain local species diversity, support species range shift and moderate species dominance. Implications for alpine management and areas for further study are also discussed.

  11. Plant regeneration from seeds responds to phylogenetic relatedness and local adaptation in Mediterranean Romulea (Iridaceae) species.

    Science.gov (United States)

    Carta, Angelino; Hanson, Sarah; Müller, Jonas V

    2016-06-01

    Seed germination is the most important transitional event between early stages in the life cycle of spermatophytes and understanding it is crucial to understand plant adaptation and evolution. However, so far seed germination of phylogenetically closely related species has been poorly investigated. To test the hypothises that phylogenetically related plant species have similar seed ecophysiological traits thereby reflecting certain habitat conditions as a result of local adaptation, we studied seed dormancy and germination in seven Mediterranean species in the genus Romulea (Iridaceae). Both the across-species model and the model accounting for shared evolutionary history showed that cool temperatures (≤ 15°C) were the main factor that promoted seed germination. The absence of embryo growth before radicle emergence is consistent with a prompt germination response at cool temperatures. The range of temperature conditions for germination became wider after a period of warm stratification, denoting a weak primary dormancy. Altogether these results indicate that the studied species exhibit a Mediterranean germination syndrome, but with species-specific germination requirements clustered in a way that follows the phylogenetic relatedness among those species. In addition, species with heavier seeds from humid habitats showed a wider range of conditions for germination at dispersal time than species from dry habitats possessing lighter seeds. We conclude that while phylogenetically related species showed very similar germination requirements, there are subtle ecologically meaningful differences, confirming the onset of adaptation to local ecological factors mediated by species relatedness.

  12. Toxic effects of traditional Ethiopian fish poisoning plant Milletia ferruginea (Hochst) seed extract on aquatic macroinvertebrates.

    Science.gov (United States)

    Karunamoorthi, K; Bishaw, D; Mulat, T

    2009-01-01

    The present investigation was carried out to evaluate the toxic effects of traditional Ethiopian fish poisoning plant Birbira [vernacular name (local native language, Amharic); Milletia ferruginea] seed extract on aquatic macroinvertebrates, Baetidae (Mayflies) and Hydropsychidae (Caddisflies), under laboratory conditions. In Ethiopia, toxic plant; Milletia ferruginea pulverized seeds have been used for fish poisoning since time immemorial. Macroinvertebrates are important biological indicators of alteration in the natural water sources. Milletia ferruginea seed extract was applied at concentrations of 125, 250, 500 1000 and 2000 ppm on Hydropsychididae whereas Baetidae were exposed at various concentrations viz., 31.25, 62.5, 125, 250 & 500 ppm. Milletia ferruginea seeds crude extract of lethal doses (LCso and LC90) required for Baetidae 49.29 mg/l and 172.52 mg/l were respectively and the respective doses (LC50 and LC90) against Hydropsychidae were 679.64 mg/l and 2383.93 mg/l. The present investigation end result demonstrated that Milletia ferruginea seed extracts were extremely toxic to Baetidae than Hydropsychididae. As a result, application of Milletia ferruginea seed extracts into the rivers/streams for fish poisoning possibly leads to contamination and disruption of food chain in the aquatic ecosystem. Therefore, the concerned authorities should launch appropriate awareness campaign among the local inhabitants and fisherman about adverse effect of Birbira seed extracts. Furthermore, providing alternative ecofriendly techniques for fish harvesting may possibly bring constructive out come in the near future.

  13. Multi-component Erlang distribution of plant seed masses and sizes

    Science.gov (United States)

    Fan, San-Hong; Wei, Hua-Rong

    2012-12-01

    The mass and the size distributions of plant seeds are very similar to the multi-component Erlang distribution of final-state particle multiplicities in high-energy collisions. We study the mass, length, width, and thickness distributions of pumpkin and marrow squash seeds in this paper. The corresponding distribution curves are obtained and fitted by using the multi-component Erlang distribution. In the comparison, the method of χ2-testing is used. The mass and the size distributions of the mentioned seeds are shown to obey approximately the multi-component Erlang distribution with the component number being 1.

  14. Preliminary design, construction and evaluation of robot of tomato seed planting for the trays of greenhouse

    Directory of Open Access Journals (Sweden)

    J Ghezavati

    2015-09-01

    Full Text Available Introduction: From an economic viewpoint, tomato is considered as the second most valuable crop after potato. It is also preceded by the potato in terms of per capita consumption in the world. In 2008, the cultivation area used for the tomato as equal to 163,539 hectares in Iran and the production of it was equal to 5,887,715 tons with an average production of 117,887 tons in 4352 hectares in the provinces, respectively. Having high production volume and quality, costly hybrid seeds are currently used for the major planting areas of vegetable in Iran. Most of the used transplanted seedlings are 83%. Since the seeds are expensive, the percentage of seedlings and healthy and disease-free seeds should be used for maximized germination and be transferred to the fields of open space. Preparing seedlings in transplanting trays is a technology to respond to this need. Trays are covered with a layer of Peat and Miculite fertilizers. Then, one seed is manually placed in each cell after gauging and preparing a suitable field. However, manually placing seeds is time-consuming and requires hard labor. Sixteen working labors per hour are required for 15 × 7 cell in order to have 10200 seedlings grown in 100 trays. Due to lack of adequate labor, production capacity of greenhouses is reduced, especially in the farming season when finding labor for planting vegetable sprouts is laborious. Therefore, mechanizing tray seeding operations is essential to increase the capacity of the growing industry of greenhouses in Iran. Materials and Methods: Initially, the tomato seeds were examined in the laboratory. The most important parameters of the study included size, shape, weight, the speed of getting out of the tank and the minimum carrying speed. Then, a vacuum-based single seed picking unit was prepared to investigate the factors influencing the design, so that a single tomato seed can be harvested from the masses. The most important factors considered in the

  15. Plants arrangement and number of seeds per hole in the agroeconomic yield of pea

    Directory of Open Access Journals (Sweden)

    Elissandra Pacito Torales

    2014-12-01

    Full Text Available The aim of this work was to study the ‘luciana 50’ pea, cultivated with different numbers of rows of plants in the plot and with two and three seeds per hill. The work carried out in Dourados-MS, between March-July 2010. Treatments were arranged in 3 x 2 factorial in randomized complete block design with six replicates. Populations corresponding to the sowing with two, three and four rows per plot were 264,000, 396,000 and 528,000 plants ha-1, respectively, with two seeds per hill, and 396,000, 594,000 and 792,000 plants ha-1, respectively, with three seeds per hill. The harvest was done at 108 days after sowing. In cultivation with four rows of plants and two seeds per hill, were obtained the highest yields of fresh and dry weight of grains and pods commercial, with increases of 29.88%, 33.85%, 29.14% and 32.22%, respectively, and higher number of grains and pods commercial, with increases of 28.13% and 27.12%, respectively, over two rows of plants with two seeds per hill. The highest yield of fresh weight of shoots, of bark and of non-commercial pods were with four rows of plants, with increases of 1.75 t ha-1, 0.44 t ha-1 and 0.47 t ha-1 respectively, compared to two rows. Considering the yield of commercial pods and grains and the estimated net income, it can be concluded that sowing of ‘Luciana 50’ pea should be performed with four rows of plants and two seeds per hill.

  16. Leading-Edge Vortices Elevate Lift of Autorotating Plant Seeds

    NARCIS (Netherlands)

    Lentink, D.; Dickson, W.B.; Leeuwen, van J.L.; Dickinson, M.H.

    2009-01-01

    As they descend, the autorotating seeds of maples and some other trees generate unexpectedly high lift, but how they attain this elevated performance is unknown. To elucidate the mechanisms responsible, we measured the three-dimensional flow around dynamically scaled models of maple and hornbeam see

  17. Some extinct plant taxa on the territory of Novi Sad and their vulnerability status in Vojvodina and Serbia

    Directory of Open Access Journals (Sweden)

    Đakić Žarko S.

    2012-01-01

    Full Text Available Natural habitats on the territory of Novi Sad are almost fully destroyed today, as well as their characteristic plant taxa. The reason for disappearance of natural habitats is the development of suburban communities, which is an irreversible process. Plant taxa, specific for wet, salty, and sandy ecosystems grew on those habitats twenty years ago and earlier. This paper presents the overview of 9 taxa (Suaeda maritima subsp. maritima, Androsace elongata subsp. elongata, Cirsium boujartii subsp. boujartii, Aster sedifolius subsp. canus, Blackstonia perfoliata subsp. serotina, Plantago maritima subsp. maritima, Salvia nutans, Allium angulosum, and Typha schuttleworthii. These taxa presented integral parts of autochthonous flora of Novi Sad. Since some of these taxa were found in the field 21 years ago and some even 93 years ago, they are extinct from the flora of Novi Sad.

  18. Biodiesel from plant seed oils as an alternate fuel for compression ignition engines-a review.

    Science.gov (United States)

    Vijayakumar, C; Ramesh, M; Murugesan, A; Panneerselvam, N; Subramaniam, D; Bharathiraja, M

    2016-12-01

    The modern scenario reveals that the world is facing energy crisis due to the dwindling sources of fossil fuels. Environment protection agencies are more concerned about the atmospheric pollution due to the burning of fossil fuels. Alternative fuel research is getting augmented because of the above reasons. Plant seed oils (vegetable oils) are cleaner, sustainable, and renewable. So, it can be the most suitable alternative fuel for compression ignition (CI) engines. This paper reviews the availability of different types of plant seed oils, several methods for production of biodiesel from vegetable oils, and its properties. The different types of oils considered in this review are cashew nut shell liquid (CNSL) oil, ginger oil, eucalyptus oil, rice bran oil, Calophyllum inophyllum, hazelnut oil, sesame oil, clove stem oil, sardine oil, honge oil, polanga oil, mahua oil, rubber seed oil, cotton seed oil, neem oil, jatropha oil, egunsi melon oil, shea butter, linseed oil, Mohr oil, sea lemon oil, pumpkin oil, tobacco seed oil, jojoba oil, and mustard oil. Several methods for production of biodiesel are transesterification, pre-treatment, pyrolysis, and water emulsion are discussed. The various fuel properties considered for review such as specific gravity, viscosity, calorific value, flash point, and fire point are presented. The review also portrays advantages, limitations, performance, and emission characteristics of engine using plant seed oil biodiesel are discussed. Finally, the modeling and optimization of engine for various biofuels with different input and output parameters using artificial neural network, response surface methodology, and Taguchi are included.

  19. Post-fire seeding of great basin native plants using conventional and minimum-till rangeland drills

    Science.gov (United States)

    Objectives of post-fire seeding in the Great Basin include reestablishment of perennial cover, suppression of exotic annual weeds, and increasingly restoration of diverse plant communities. Non-conventional seeding techniques may be required when seeding mixes of grasses, forbs and shrubs containing...

  20. Effect of Planting Methods and Seeding Rates on Yield of Alfalfa (Medicago sativa L. CV. Hamedani in Bajgah, Fars Province

    Directory of Open Access Journals (Sweden)

    A. Yazdani

    2015-06-01

    ha-1, respectively. Seeding rates also had a significant effect on number of weeds so that maximum and minimum weed numbers were obtained in 20 kg and 5 kg seed ha-1. Our results showed that 20 kg seed ha-1 and furrow planting method was the best treatment to gain maximum forage yield and minimum weed's detrimental impact.

  1. Hydroquinone; A novel bioactive compound from plant-derived smoke can cue seed germination of lettuce

    Science.gov (United States)

    Kamran, Muhammad; Khan, Abdul L.; Ali, Liaqat; Hussain, Javid; Waqas, Muhammad; Al-Harrasi, Ahmed; Imran, Qari M.; Kim, Yoon-Ha; Kang, Sang-Mo; Yun, Byung-Wook; Lee, In-Jung

    2017-05-01

    Plant-derived smoke has been known to play an important role in distribution and growth of vegetation. Using a proficiently designed furnace, we extracted smoke from the leaves of four plant viz. Helianthus annuus, Aloe vera, Ginkgo biloba, and Cymbopogon jwarancusa. Smoke dilutions obtained from these plants were obtained in different concentrations to identify potential lettuce growth promoting smoke solution. Results revealed that smoke obtained from Ginkgo biloba significantly enhanced the lettuce seed germination. This solution was then partitioned into ethyl acetate, dichloromethane, n-hexane, chloroform and ether fractions. Ethyl acetate fraction was found to be potent to enhance seed germination. This fraction was subjected to column chromatography and spectroscopic techniques to obtain compound 1. This compound was identified as hydroquinone using 1D and 2D NMR techniques. At low concentrations (5, 10 and 20 ppm), compound 1 enhanced the lettuce seed germination; however, higher concentrations inhibited its growth as compared to control.

  2. Assessing the potential of candidate DNA barcodes for identifying non-flowering seed plants.

    Science.gov (United States)

    Pang, X; Luo, H; Sun, C

    2012-09-01

    In plants, matK and rbcL have been selected as core barcodes by the Consortium for the Barcode of Life (CBOL) Plant Working Group (PWG), and ITS/ITS2 and psbA-trnH were suggested as supplementary loci. Yet, research on DNA barcoding of non-flowering seed plants has been less extensive, and the evaluation of DNA barcodes in this division has been limited thus far. Here, we evaluated seven markers (psbA-trnH, matK, rbcL, rpoB, rpoC1, ITS and ITS2) from non-flowering seed plants. The usefulness of each region was assessed using four criteria: the success rate of PCR amplification, the differential intra- and inter-specific divergences, the DNA barcoding gap and the ability to discriminate species. Among the seven loci tested, ITS2 produced the best results in the barcoding of non-flowering seed plants. In addition, we compared the abilities of the five most-recommended markers (psbA-trnH, matK, rbcL, ITS and ITS2) to identify additional species using a large database of gymnosperms from GenBank. ITS2 remained effective for species identification in a wide range of non-flowering seed plants: for the 1531 samples from 608 species of 80 diverse genera, ITS2 correctly authenticated 66% of them at the species level. In conclusion, the ITS2 region can serve as a useful barcode to discriminate non-flowering seed plants, and this study will contribute valuable information for the barcoding of plant species.

  3. Evolution of plant cell wall: Arabinogalactan-proteins from three moss genera show structural differences compared to seed plants.

    Science.gov (United States)

    Bartels, Desirée; Baumann, Alexander; Maeder, Malte; Geske, Thomas; Heise, Esther Marie; von Schwartzenberg, Klaus; Classen, Birgit

    2017-05-01

    Arabinogalactan-proteins (AGPs) are important proteoglycans of plant cell walls. They seem to be present in most, if not all seed plants, but their occurrence and structure in bryophytes is widely unknown and actually the focus of AGP research. With regard to evolution of plant cell wall, we isolated AGPs from the three mosses Sphagnum sp., Physcomitrella patens and Polytrichastrum formosum. The moss AGPs show structural characteristics common for AGPs of seed plants, but also unique features, especially 3-O-methyl-rhamnose (trivial name acofriose) as terminal monosaccharide not found in arabinogalactan-proteins of angiosperms and 1,2,3-linked galactose as branching point never found in arabinogalactan-proteins before. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. A New Approach to Modify Plant Microbiomes and Traits by Introducing Beneficial Bacteria at Flowering into Progeny Seeds

    Science.gov (United States)

    Mitter, Birgit; Pfaffenbichler, Nikolaus; Flavell, Richard; Compant, Stéphane; Antonielli, Livio; Petric, Alexandra; Berninger, Teresa; Naveed, Muhammad; Sheibani-Tezerji, Raheleh; von Maltzahn, Geoffrey; Sessitsch, Angela

    2017-01-01

    The microbial component of healthy seeds – the seed microbiome – appears to be inherited between plant generations and can dynamically influence germination, plant performance, and survival. As such, methods to optimize the seed microbiomes of major crops could have far-reaching implications for plant breeding and crop improvement to enhance agricultural food, feed, and fiber production. Here, we describe a new approach to modulate seed microbiomes of elite crop seed embryos and concomitantly design the traits to be mediated by seed microbiomes. Specifically, we discovered that by introducing the endophyte Paraburkholderia phytofirmans PsJN to the flowers of parent plants we could drive its inclusion in progeny seed microbiomes, thereby inducing vertical inheritance to the offspring generation. We demonstrated the introduction of PsJN to seeds of monocot and dicot plant species and the consequential modifications to seed microbiome composition and growth traits in wheat, illustrating the potential role of novel seed-based microbiomes in determining plant traits. PMID:28167932

  5. In vivo monitoring of seeds and plant-tissue water absorption using optical coherence tomography and optical coherence microscopy

    Science.gov (United States)

    Sapozhnikova, Veronika V.; Kutis, Irina S.; Kutis, Sergey D.; Kuranov, Roman V.; Gelikonov, Grigory V.; Shabanov, Dmitry V.; Kamensky, Vladislav A.

    2004-07-01

    First experimental results on OCT imaging of internal structure of plant tissues and in situ OCT monitoring of plant tissue regeneration at different water supply are reported. Experiments for evaluating OCT capabilities were performed on Tradescantia. The investigation of seeds swelling was performed on wheat seeds (Triticum L.), barley seeds (Hordeum L.), long-fibred flax seeds (Linum usitatissimum L.) and cucumber seeds (Cucumis sativus L.). These OCT images correlate with standard microscopy data from the same tissue regions. Seeds were exposed to a low-intensity physical factor-the pulsed gradient magnetic field (GMF) with pulse duration 0.1 s and maximum amplitude 5 mT (4 successive pulses during 0.4 s). OCT and OCM enable effective monitoring of fast reactions in plants and seeds at different water supply.

  6. Seed production of woody plants in conditions of environment pollution by metallurgical industry emissions

    Directory of Open Access Journals (Sweden)

    Z. V. Gritzay

    2011-10-01

    Full Text Available The influence of environment pollution by metallurgical industry emissions on woody plants bearing parameters was examined. The results obtained show the decrease of bearing rate, diminution of seeds, fruits and seed cells sizes in woody plants affected by technogenic emissions. Attenuation of the 1000 seeds’ weight was established. Incresing the amount of fruits with development deviations was ascertained. It was found aplasia and abnormal form of the samara fruit of ash and ailanthus trees, arcuation and narrowing of some parts of the catalpa fruitcases. Practical recommendations on using seeds’ sensitive parameters in biomonitoring of woody phytocenoses under technogenic stressful conditions are proposed.

  7. Treatment of Arabidopsis thaliana seeds with an HSP90 inhibitor increases plant resistance

    Science.gov (United States)

    Kozeko, Liudmyla

    2016-07-01

    Resistance of plants to unfavourable conditions is an important feature to use them as an autotrophic link of Life Support Systems in space exploration missions. It significantly depends on basic and stress-induced levels of heat shock proteins (HSP) in cells. It is known that HSP90 can bind and maintain heat shock transcription factors (HSF) as a monomer that lacks DNA binding activity and thereby regulate HSP expression. Modulation of activity of the HSP synthesis and resistance by HSP90 in plants is not well investigated. The objective of this study was to determine how treatment of seeds with an HSP90 inhibitor affects environmental responsiveness in Arabidopsis thaliana. Seed treatment with geldanamycin (GDA) was used to reduce HSP90 function. The affect of space flight stressors was simulated by gamma-irradiation and thermal upshift. Two series of experiments were carried out: 1) exposure of dry seeds to gamma-irradiation (1 kGy, ^{60}Co); 2) heat shock of seedlings. It was shown that GDA treatment of seeds stimulated the seedling growth after seed irradiation. It also increased both the basic thermotolerance (45°C for 45 min) and induced thermotolerance (45°C for 1,5-2,5 h after pretreatment at 37°C for 2 h) in seedlings. In addition, seed treatment with GDA had a prolonged effect on the HSP70 production in seedlings under normal and stressful conditions. It shows that the stimulatory effects of GDA may be caused by induction of HSP70 synthesis. The obtained data demonstrate that pre-treatment of seeds with GDA before planting allows inducing the stress resistance at least at early growth stages of plants.

  8. Does Seed Priming Induce Changes in the Levels of Some Endogenous Plant Hormones in Hexaploid Wheat Plants Under Salt Stress?

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to assess whether salt tolerance could be improved in spring wheat (Triticum aestivum L.), the present study was performed by soaking the seeds of two cultivars, namely MH-97 (salt sensitive) and Inqlab91 (salt tolerant), for 12 h in distilled water or 100 mol/m3 CaCl2, KCl, or NaCl. Primed seeds from each treatment group and non-primed seeds were sown in a field in which NaCl salinity of 15 dS/m was developed. Priming of seeds with CaCl2, followed by priming with KCl and NaCl, was found to be effective in alleviating the adverse effects of salt stress on both wheat cultivars in terms of shoot fresh and dry weights and grain yield. Priming with CaCl2 alleviated the adverse effects of salt stress on hormonal balance in plants of both cultivars. In MH-97plants, CaCl2 pretreatment considerably reduced leaf abscisic acid (ABA) concentrations and increased leaf free salicylic acid (SA) concentrations under both saline and non-saline conditions. In contrast, in the Inqlab-91plant, CaCl2 increased free indoleacetic acid (IAA) and indolebutyric acid (IBA) content. However, priming of seeds with CaCl2 did not alter free polyamine levels in either cultivar, although spermidine levels were considerably lower in plants raised from seeds treated with CaCl2 for both cultivars under saline conditions. Priming with KCl increased growth in Inqlab-91 plants, but not in MH-97 plants, under saline conditions. The salinity induced reduction in auxins (IAA and IBA) was alleviated by NaCl priming in both cultivars under saline conditions.However, NaCl increased leaf free ABA content and lowered leaf SA and putrescine levels in Inqlab-91 plants under saline conditions. In conclusion, although all three priming agents (i.e. CaCl2, KCl, and NaCI) were effective in alleviating the adverse effects of salt stress on wheat plants, their effects on altering the levels of different plant hormones were different in the two cultivars.

  9. Seed quality effects on seedling emergence, plant stand establishment and grain yield in two-row barley

    Directory of Open Access Journals (Sweden)

    A. RAJALA

    2008-12-01

    Full Text Available Seed viability and vigour play important roles in seedling emergence, plant stand establishment and yield potential. The majority of cereal fields in Finland are typically sown with farm saved seed (FSS. If the quality of the seed is not known, there can be insidious yield reduction. This research was conducted to study the effects of seed quality on seedling emergence rate, seedling number and yielding capacity. The study comprised three-year field experiments conducted during 2007–2009, established at three sites: Jokioinen, Nousiainen and Ylistaro. Spring barley cultivars Saana (2007 and Annabell (2008-2009 were sown at rate of 500 germinating seeds m-2. Five seed lots were included as treatments: farm saved seed (FSS; downgraded seed 2.7 mm; upgraded seed >2.7 mm with disinfection (FSS>2.7 mm + dis; and commercial certified seed with disinfection (CCS. Up- and down-graded seed lots (FSS2.7 mm, and FSS>2.7 mm + dis all originated from the FSS. Seedling emergence rate was measured from the time when coleoptiles started to break through the soil surface. The number of seedlings (3 × 1 m row per plot was recorded at five-day intervals four times from the same rows. Plots were harvested at physiological maturity and grain yield (kg ha-1, hectolitre weight (HLW, kg single grain weight (SGW, mg and grain protein content (% were recorded. Seed lots of CCS and FSS>2.7 mm + dis enhanced seedling emergence rate and increased the number of plants compared with other treatments. These two seed lots also produced the highest grain yield and had the lowest grain protein. Seed quality had an apparent effect on plant stand establishment and grain yield. A seed lot effect was evident despite identical targeted sowing rates that took into account germination rate and seed weight. Therefore, differences in seedling emergence and yielding capacity were likely outcomes of variation in seed vigour among the five treatments.;

  10. Seed Bank Contribution to Vascular Plant Richness on Temporary Floating Islands

    Science.gov (United States)

    Cherry, J. A.

    2005-05-01

    Fluctuating water levels create opportunities for recruitment of new individuals from wetland seed banks. In this study, floating island formation functioned similarly to drawdowns in water level by creating patches of sediment that were less inundated than the surrounding, undisturbed deep-water marsh. To examine if and how seed banks contributed to temporary formation of distinct plant assemblages on these islands, field surveys of plant percent cover on and off of islands were conducted over two years, along with a controlled greenhouse experiment in which inundation was manipulated. Plant assemblages differed significantly on and off of floating islands. Floating-leaved perennials dominated undisturbed deep-water marsh, while emergent species dominated floating islands. Moreover, species richness was greater on islands than in the undisturbed deep-water marsh. Plant assemblages in the greenhouse experiment also differed among inundation treatments in a manner consistent with differences observed in field surveys. These results demonstrate that floating island formation temporarily altered levels of inundation favoring the germination of a more species-rich, emergent plant assemblage. Because these islands persisted long enough for several species to set seed, their formation may contribute to the maintenance of the seed bank and help maintain populations of otherwise rare species within the deep-water marsh.

  11. Control of Seed Germination and Plant Development by Carbon and Nitrogen Availability

    Science.gov (United States)

    Osuna, Daniel; Prieto, Pilar; Aguilar, Miguel

    2015-01-01

    Little is known about the molecular basis of the influence of external carbon/nitrogen (C/N) ratio and other abiotic factors on phytohormones regulation during seed germination and plant developmental processes, and the identification of elements that participate in this response is essential to understand plant nutrient perception and signaling. Sugars (sucrose, glucose) and nitrate not only act as nutrients but also as signaling molecules in plant development. A connection between changes in auxin transport and nitrate signal transduction has been reported in Arabidopsis thaliana through the NRT1.1, a nitrate sensor and transporter that also functions as a repressor of lateral root growth under low concentrations of nitrate by promoting auxin transport. Nitrate inhibits the elongation of lateral roots, but this effect is significantly reduced in abscisic acid (ABA)-insensitive mutants, what suggests that ABA might mediate the inhibition of lateral root elongation by nitrate. Gibberellin (GA) biosynthesis has been also related to nitrate level in seed germination and its requirement is determined by embryonic ABA. These mechanisms connect nutrients and hormones signaling during seed germination and plant development. Thus, the genetic identification of the molecular components involved in nutrients-dependent pathways would help to elucidate the potential crosstalk between nutrients, nitric oxide (NO) and phytohormones (ABA, auxins and GAs) in seed germination and plant development. In this review we focus on changes in C and N levels and how they control seed germination and plant developmental processes through the interaction with other plant growth regulators, such as phytohormones. PMID:26635847

  12. Seed and Root Endophytic Fungi in a Range Expanding and a Related Plant Species

    Directory of Open Access Journals (Sweden)

    Stefan Geisen

    2017-08-01

    Full Text Available Climate change is accelerating the spread of plants and their associated species to new ranges. The differences in range shift capacity of the various types of species may disrupt long-term co-evolved relationships especially those belowground, however, this may be less so for seed-borne endophytic microbes. We collected seeds and soil of the range-expanding Centaurea stoebe and the congeneric Centaurea jacea from three populations growing in Slovenia (native range of both Centaurea species and the Netherlands (expanded range of C. stoebe, native range of C. jacea. We isolated and identified endophytic fungi directly from seeds, as well as from roots of the plants grown in Slovenian, Dutch or sterilized soil to compare fungal endophyte composition. Furthermore, we investigated whether C. stoebe hosts a reduced community composition of endophytes in the expanded range due to release from plant-species specific fungi while endophyte communities in C. jacea in both ranges are similar. We cultivated 46 unique and phylogenetically diverse endophytes. A majority of the seed endophytes resembled potential pathogens, while most root endophytes were not likely to be pathogenic. Only one endophyte was found in both roots and seeds, but was isolated from different plant species. Unexpectedly, seed endophyte diversity of southern C. stoebe populations was lower than of populations from the north, while the seed endophyte community composition of northern C. stoebe populations was significantly different southern C. stoebe as well as northern and southern C. jacea populations. Root endophyte diversity was considerably lower in C. stoebe than in C. jacea independent of plant and soil origin, but this difference disappeared when plants were grown in sterile soils. We conclude that the community composition of fungal endophytes not only differs between related plant species but also between populations of plants that expand their range compared to their native

  13. Influence of Seeding Rate on Weed Density in Soybean Planting System for Southeastern Coastal Plains

    Directory of Open Access Journals (Sweden)

    Pawel Wiatrak

    2011-01-01

    Full Text Available Problem statement: Increasing seeding rates may help decrease weed pressure in soybean [Glycine max (L. Merr.] wide row spacing. Approach: The objective of this study was to evaluate the influence of five glyphosate-resistant soybean Maturity Groups (MG (IV, V, VI, VII and VIII and six seeding rates (68,000,136,000, 204,000, 272,000, 340,000 and 408,000 seeds ha-1 on weed density under dryland conditions on the Southeastern coastal plain in 2007-2009. Results: Weed decrease with increasing seeding rate varied over years. Weed density was generally lower at higher seeding rates for most MG soybeans at 30 and 60 DAP, except MG IV and VIII at 30 DAP in 2007 and MG VI at 30 DAP in 2008. At 60 DAP, soybean leaf area index (LAI and normalized difference vegetation index (NDVI were greater with lower weed density. Conclusion: Additionally, negative correlations were observed between weed density and plant LAI/NDVI for all MG in 2008 and MG IV through VI in 2009. These results suggest that increased seeding rates may help decrease weed pressure and improve soybean growth at early growth stages. However the response of weed pressure to seeding rate may vary over years and depend on MG soybean.

  14. Arachidonic and eicosapentaenoic acids in Araucariaceae, a unique feature among seed plants

    Directory of Open Access Journals (Sweden)

    Wolff Robert L.

    2000-01-01

    Full Text Available It is generally admitted that seed plants (spermaphytes are unable to synthesize either arachidonic or eicosapentaenoic acids (AA and EPA, the classic essential fatty acids in animals. We give here chromatographic and spectrometric data showing that species from the primitive family Araucariaceae (gymnosperms are able to synthesize AA and/or EPA in their seeds and leaves. Agathis robusta, in particular, contains AA and EPA in small amounts in its seeds, with no D5-unsaturated polymethylene-interrupted fatty acids (D5-UPIFA with 18 carbon atoms, whereas Araucaria spp. contain both AA and C18 D5-UPIFA. In both species, D5-UPIFA with 20 carbon atoms are present as in all other Coniferophytes. All metabolic intermediates necessary for the biosynthesis of AA and/or EPA have been characterized in Araucariaceae seeds. The relevance of these observations is discussed with regard to the phylogeny of Coniferophytes.

  15. Seed harvesting of a threatened African tree dispersed by rodents: Is enrichment planting a solution?

    Directory of Open Access Journals (Sweden)

    Carrie E. Seltzer

    2015-01-01

    Full Text Available Non-timber forest products (NTFPs provide income to local communities with less ecological harm than timber extraction. Yet overharvesting can still influence the regeneration and sustainability of these resources. Developing sustainable harvesting practices for emerging NTFPs depends on the biology of the NTFP species, the ecological context in which management occurs, and its cost in terms of effort and resources. Allanblackia stuhlmannii (Clusiaceae is a canopy tree species whose seeds are a source of vegetable oil and an important food for rodents. In an experiment within the Amani Nature Reserve (Tanzania, we studied how enrichment planting of A. stuhlmannii seeds affected germination and establishment rates under varying local levels of seed abundance and rodent activity. Overall, germination and establishment rates were high (4.8% and 2.2%, respectively, after 11 months, while local ecological conditions had a short lived (1–2 weeks and unexpectedly small influence on the persistence of planted seeds. Given these rates, we estimate a cost of approximately US$0.14 per seedling. Enrichment planting of seeds, across a range of local ecological conditions, appears to be a viable and cost effective management strategy for increasing A. stuhlmannii recruitment in harvested areas.

  16. Protocol for Large-Scale Collection, Processing, and Storage of Seeds of Two Mesohaline Submerged Aquatic Plant Species

    Science.gov (United States)

    2006-08-01

    quantities sufficient to restore underwater grass habitats on a scale of hectares. Although this system was developed for P. perfoliatus and R. maritima...dispersing plants to new habitats . Embryos formed in seeds are better protected and have more abundant food reserves than those in other plant groups like...the bryophytes and pterido- phytes (Batygina 2002, Fernald 1970). Auxiliary seed tissues provide mechanisms for efficient embryo (seed) dispersal

  17. The presence of a below-ground neighbour alters within-plant seed size distribution in Phaseolus vulgaris

    NARCIS (Netherlands)

    Chen, B.; During, H.J.; Vermeulen, P.J.; Anten, N.P.R.

    2014-01-01

    * Background and Aims Considerable variation in seed size commonly exists within plants, and is believed to be favoured under natural selection. This study aims to examine the extent to which seed size distribution depends on the presence of competing neighbour plants. * Methods Phaseolus vulgaris p

  18. Does seeding after severe forest fires in western USA mitigate negative impacts on soils and plant communities?

    Science.gov (United States)

    D. Peppin; P. Fule; J. Beyers; C. Sieg; M. Hunter

    2011-01-01

    Broadcast seeding is one of the most widely used post-wildfire emergency response treatments intended to reduce soil erosion, increase vegetative ground cover, and minimize establishment and spread of non-native plant species. However, seeding treatments can also have negative effects such as competition with recovering native plant communities and inadvertent...

  19. Influence of seed size and weight used in sowing on common bird’s-foot-trefoil (Lotus corniculatus L. Plant vigour

    Directory of Open Access Journals (Sweden)

    Toth Ilie

    2015-10-01

    Full Text Available Growth and development of common bird’s-foot-trefoil (Lotus corniculatus L. plants are influenced by seed size and weight upon sowing. Studies show that the five seed size groups influence plant vigour, i.e. a 2-4 times increase of morphological organs (roots, seedlings, leaves in larger and heavier seed group than in smaller and lighter seed group. This increase was also pointed out by the strong correlations between seed size and plant vigour.

  20. Concerning the preliminary results of space experiment with the seeds of rare plants (on the boad of BION-M No.1)

    Science.gov (United States)

    Gorelov, Yury; Kurganskaya, Lubov; Ilyin, Vyacheslav; Ruzaeva, Irina; Rozno, Svetlana; Kavelenova, Ludmila

    The problem of native flora plants conservation appears today as one of the most actual for humanity. The wide spreading natural ecosystems degradation results in the status changes for formerly common species to rare, endangered or extincted ones. That is why the complex of biological diversity conservation measures must be used including ex situ and in situ forms. Last years the seed banks (special seed collections in controlled conditions, including temperature below zero) and field banks (special alive plants collections) were created in many countries taking in mind the future of humanity. The seed banks as long-term depositories can be placed on the space stations where the threat of earth catastrophes is removed. But we must make it clear how the complex of space flight factors effects upon the seed quality and germination and plants development from “cosmic” seeds. For instance, the action of residual ionizing radiation into space apparatus on plant seeds can alter its vitality maybe by the growth of free radicals pool in molecular and subcellular level. The unknown level of such action permits us to propose wide diapason of effects from the absence of any changes to the stimulation of vital activity, decrease of it, mutagenesis and maybe the death of seeds. Only the experiments that begin in space and continue on the Earth can show us the effect of space flight factors complex on plant seeds. Here we describe the first results of experiment held on the board of space apparatus “Bion-M” No1. Totally 79 experiments were included to the program of “Bion-M”, among them the experiment “Biocont-BS”. The equipment for it was prepared by Central Scientific Research Institute of Machine-building; the seed material was selected and prepared by the Botanical Garden of Samara State University. The equipment with seeds was into space apparatus, which working orbit was average 575 km and the flight lasted for 30 days. The seed samples of 9 rare plants

  1. The influence of seed treatment with gamma radiation on plant yield

    DEFF Research Database (Denmark)

    Mølle, K.G.

    1965-01-01

    to 20,000 rads. The experiments were run either as pot or as field experiments, with varying growing periods up to maturity. The experimental data included germination percentage and yield of dry matter, as well as other plant characters, e.g. plant height and number of leaves per plant. The dry......The effect of seed irradiation with γ-rays on the yield of plants has been examined for the following species: Spring barley, spring and winter wheat, winter rye, maize, fodder pea, white mustard, fodder beet, and radish. Cobalt-60 was used as the source of radiation, with doses varying from 10...

  2. Protamine sulfate precipitation method depletes abundant plant seed-storage proteins: A case study on legume plants.

    Science.gov (United States)

    Kim, Yu Ji; Wang, Yiming; Gupta, Ravi; Kim, So Wun; Min, Chul Woo; Kim, Yong Chul; Park, Ki Hun; Agrawal, Ganesh Kumar; Rakwal, Randeep; Choung, Myoung-Gun; Kang, Kyu Young; Kim, Sun Tae

    2015-05-01

    Depletion of abundant proteins is one of the effective ways to improve detection and identification of low-abundance proteins. Our previous study showed that protamine sulfate precipitation (PSP) method can deplete abundant ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) from leaf proteins and is suitable for their in-depth proteome investigation. In this study, we provide evidence that the PSP method can also be effectively used for depletion of abundant seed-storage proteins (SSPs) from the total seed proteins of diverse legume plants including soybean, broad bean, pea, wild soybean, and peanut. The 0.05% protamine sulfate (PS) was sufficient to deplete major SSPs from all legumes tested except for peanut where 0.1% PS was required. SDS-PAGE, Western blotting and 2DE analyses of PS-treated soybean and peanut seed proteins showed enriched spots in PS-supernatant than total proteins. Coefficient of variation percentage (%CV) and principal component analysis of 2DE spots support the reproducibility, suitability, and efficacy of the PSP method for quantitative and comparative seed proteome analysis. MALDI-TOF-TOF successfully identified some protein spots from soybean and peanut. Hence, this simple, reproducible, economical PSP method has a broader application in depleting plant abundant proteins including SSPs in addition to RuBisCO, allowing discussion for comprehensive proteome establishment and parallel comparative studies in plants.

  3. Effects of Ambient Humidity on Plant Growth Enhancement by Atmospheric Air Plasma Irradiation to Plant Seeds

    Science.gov (United States)

    Sarinont, Thapanut; Amano, Takaaki; Koga, Kazunori; Shiratani, Masaharu

    2015-09-01

    Humidity is an important factor for plasma-bio applications because composition of species generated by atmospheric pressure plasmas significantly depends on the humidity. Here we have examined effects of humidity on the growth enhancement to study the mechanism. Experiments were carried out with a scalable DBD device. 10 seeds of Raphanus sativus L. were set for x = 5 mm and y = 3 mm below the electrodes. The humidity Hair was 10 - 90 %Rh. The ratio of length of plants with plasma irradiation to that of control increases from 1.2 for Hair = 10 %Rh to 2.5 for Hair = 50 %Rh. The ratio is 2.5 for Hair = 50-90 %Rh. This humidity dependence is similar to the humidity dependence of O2+-H2O,H3O*, NO2--H2Oand NO3--H2Odensities, whereas it is different from that of other species such as O3, NO, and so on. The similarity gives information on key species for the growth enhancement.

  4. APPLICATION OF PLANT GROWTH-PROMOTING RHIZOBACTERIA TO RUNNER BEAN INCREASES SEED CARBOHYDRATE AND PROTEIN YIELD

    OpenAIRE

    Marius Stefan; Neculai Munteanu; Marius Mihasan

    2013-01-01

    The potential of two rhizobacterial strains with plant growth promoting capabilities (mineral phosphate solubilization and IAA production traits) to influence the nutritive value of runner bean grains was assessed on plants cultivated in organic crop system. Seed inoculation with rhizobacterial strains improve the nutritive value of the harvested grains by enhancing the soluble protein content up to 11.97 % and total reducing carbohydrates content up to 28.97%. The number of fractions detecte...

  5. Developmental peculiarities and seed-borne endophytes in quinoa: Omnipresent, robust bacilli contribute to plant fitness.

    Directory of Open Access Journals (Sweden)

    Andrea ePitzschke

    2016-01-01

    Full Text Available Among potential climate change-adapted crops for future agriculture, quinoa (Chenopodium quinoa, a facultative halophyte plant with exceptional nutritional properties, stands out as a prime candidate. This work examined how quinoa deals with extreme situations during seed rehydration. A seed-borne microbiome was discovered and its potential role in early development and stress resistance investigated.Methods involved germination and drought exposure assays, histochemical detection of reactive oxygen species, and diverse tests with seed(ling material to assess microbial occurrence, release and proliferation. Quinoa´s microbial partners were biochemically, microscopically and taxonomically characterized.Quinoa distinguishes itself from other plants in multiple ways. It germinates within minutes, even under extremely hostile conditions. Broken seeds/split embryos are able to regenerate. Furthermore, quinoa seedlings are resurrection-competent. These peculiarities became in part explainable upon discovery of seed-borne microorganisms. 100% of quinoa seeds, from different sources, are inhabited by bacteria of the genus Bacillus. These endophytes are mobile and reside in all seedling organs, indicating vertical transmission. Owing to their strong catalase activity and high superoxide contents they can modify host redox properties. One outcome is cell expansion, enabling quinoa to overcome a critical period in development, seedling establishment.Quinoa´s immediate confrontation with foreign ROS and bacterial elicitors likely induces a naturally primed state, enabling plants to withstand extreme situations. The endophytic bacteria, which are cultivable and highly robust themselves, have high potential for application in agriculture, food (amylase and cosmetics (catalase industry. An exciting question arising from this work is: Can quinoa´s microbiome be transferred to improve stress resistance in other plant species?

  6. Seed and root endophytic fungi in a range expanding and a related plant species

    NARCIS (Netherlands)

    Geisen, Stefan; Kostenko, Olga; Cnossen, Mark C.; Hooven, ten Freddy C.; Vreš, Branko; Putten, van der Wim H.

    2017-01-01

    Climate change is accelerating the spread of plants and their associated species to new ranges. The differences in range shift capacity of the various types of species may disrupt long-term co-evolved relationships especially those belowground, however, this may be less so for seed-borne

  7. Seed and root endophytic fungi in a range expanding and a related plant species

    NARCIS (Netherlands)

    Geisen, Stefan; Kostenko, Olga; Cnossen, Mark C.; ten Hooven, Freddy C.; Vreš, Branko; van Der Putten, Wim H.

    2017-01-01

    Climate change is accelerating the spread of plants and their associated species to new ranges. The differences in range shift capacity of the various types of species may disrupt long-term co-evolved relationships especially those belowground, however, this may be less so for seed-borne endophytic

  8. Developmental Peculiarities and Seed-Borne Endophytes in Quinoa: Omnipresent, Robust Bacilli Contribute to Plant Fitness.

    Science.gov (United States)

    Pitzschke, Andrea

    2016-01-01

    Among potential climate change-adapted crops for future agriculture, quinoa (Chenopodium quinoa), a facultative halophyte plant with exceptional nutritional properties, stands out as a prime candidate. This work examined how quinoa deals with extreme situations during seed rehydration. Quinoa distinguishes itself from other plants in multiple ways. It germinates within minutes, even under extremely hostile conditions. Broken seeds/split embryos are able to regenerate. Furthermore, quinoa seedlings are resurrection-competent. These peculiarities became in part explainable upon discovery of seed-borne microorganisms. 100% of quinoa seeds, from different sources, are inhabited by diverse members of the genus Bacillus. These endophytes are motile and reside in all seedling organs, indicating vertical transmission. Owing to their high catalase activities and superoxide contents the bacteria potentially manipulate the host's redox status. Superoxide-driven cell expansion enables quinoa to overcome a critical period in development, seedling establishment. Quinoa's immediate confrontation with "foreign" reactive oxygen species and bacterial elicitors likely induces a naturally primed state, enabling plants to withstand extreme situations. The endophytic bacteria, which are cultivable and highly robust themselves, have high potential for application in agriculture, food (amylase) and cosmetics (catalase) industry. This work also discusses the potential of transferring quinoa's microbiome to improve stress resistance in other plant species.

  9. Planting the Seeds: Growth in Rural Education [Two]... A Series of Choices

    Science.gov (United States)

    Online Submission, 2006

    2006-01-01

    "Planting the Seeds: Growth in Rural Education [Two]... A Series of Choices" outlines nine effective practices in programming for small and rural schools. The nine projects are described and additional resources, contacts, and references are provided for each. The nine projects include an outreach school partnership, the use of a mobile…

  10. Eliminating anti-nutritional plant food proteins: the case of seed protease inhibitors in pea.

    Science.gov (United States)

    Clemente, Alfonso; Arques, Maria C; Dalmais, Marion; Le Signor, Christine; Chinoy, Catherine; Olias, Raquel; Rayner, Tracey; Isaac, Peter G; Lawson, David M; Bendahmane, Abdelhafid; Domoney, Claire

    2015-01-01

    Several classes of seed proteins limit the utilisation of plant proteins in human and farm animal diets, while plant foods have much to offer to the sustainable intensification of food/feed production and to human health. Reduction or removal of these proteins could greatly enhance seed protein quality and various strategies have been used to try to achieve this with limited success. We investigated whether seed protease inhibitor mutations could be exploited to enhance seed quality, availing of induced mutant and natural Pisum germplasm collections to identify mutants, whilst acquiring an understanding of the impact of mutations on activity. A mutant (TILLING) resource developed in Pisum sativum L. (pea) and a large germplasm collection representing Pisum diversity were investigated as sources of mutations that reduce or abolish the activity of the major protease inhibitor (Bowman-Birk) class of seed protein. Of three missense mutations, predicted to affect activity of the mature trypsin / chymotrypsin inhibitor TI1 protein, a C77Y substitution in the mature mutant inhibitor abolished inhibitor activity, consistent with an absolute requirement for the disulphide bond C77-C92 for function in the native inhibitor. Two further classes of mutation (S85F, E109K) resulted in less dramatic changes to isoform or overall inhibitory activity. The alternative strategy to reduce anti-nutrients, by targeted screening of Pisum germplasm, successfully identified a single accession (Pisum elatius) as a double null mutant for the two closely linked genes encoding the TI1 and TI2 seed protease inhibitors. The P. elatius mutant has extremely low seed protease inhibitory activity and introgression of the mutation into cultivated germplasm has been achieved. The study provides new insights into structure-function relationships for protease inhibitors which impact on pea seed quality. The induced and natural germplasm variants identified provide immediate potential for either halving

  11. Response of perennial woody plants to seed treatment by electromagnetic field and low-temperature plasma.

    Science.gov (United States)

    Mildaziene, Vida; Pauzaite, Giedre; Malakauskiene, Asta; Zukiene, Rasa; Nauciene, Zita; Filatova, Irina; Azharonok, Viktor; Lyushkevich, Veronika

    2016-08-30

    Radiofrequency (5.28 MHz) electromagnetic radiation and low-temperature plasma were applied as short-term (2-15 min) seed treatments to two perennial woody plant species, including Smirnov's rhododendron (Rhododendron smirnowii Trautv.) and black mulberry (Morus nigra L.). Potential effects were evaluated using germination indices and morphometry. The results suggest that treatment with electromagnetic field stimulated germination of freshly harvested R. smirnowii seeds (increased germination percentage up to 70%), but reduced germination of fresh M. nigra seeds (by 24%). Treatment with low-temperature plasma negatively affected germination for R. smirnowii, and positively for M. nigra. The treatment-induced changes in germination depended on seed dormancy state. Longer-term observations revealed that the effects persisted for more than a year; however, even negative effects on germination came out as positive effects on plant morphometric traits over time. Treatments characterized as distressful based on changes in germination and seedling length increased growth of R. smirnowii after 13 months. Specific changes included stem and root branching, as well as increased leaf count and surface area. These findings imply that longer-term patterns of response to seed stressors may be complex, and therefore, commonly used stressor-effects estimates, such as germination rate or seedling morphology, may be insufficient for qualifying stress response. Bioelectromagnetics. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Transport via xylem and accumulation of aflatoxin in seeds of groundnut plant.

    Science.gov (United States)

    Snigdha, M; Hariprasad, P; Venkateswaran, G

    2015-01-01

    Aflatoxin contamination in groundnut seeds in the absence of any aflatoxigenic fungi leads to a hypothesis that aflatoxins are present naturally in soil and is transferred to seeds through uptake by roots. A survey was conducted on the natural occurrence of aflatoxins in agricultural soils, among nine main groundnut-growing regions of Karnataka state, India. All 71 soil samples collected in this survey were contaminated with aflatoxins esp. AFB1. An in vitro xylem sap experiment proved the ability of groundnut plant roots to absorb AFB1, and transport to aerial plant parts via the xylem. Hydroponics experiment also proved the uptake of AFB1 by the roots and their translocation to shoot. Uptake was affected by the initial concentration of toxin and pH of the medium. Among the 14 varieties screened, GPBD4 and MLT.K.107 (III) recorded highest and least AFB1 uptake, respectively. The above results were validated using a greenhouse experiment. Here, the aflatoxin absorbed by root gradually transferred to shoot that was later found in seeds towards the end of experiment. Thus, the groundnut seeds can also get contaminated with aflatoxin by direct uptake of aflatoxin through conducting tissue in addition to fungal infection. The present study revealed the novel mode of aflatoxin contamination in groundnut seeds without fungal infection. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Joint estimation of contemporary seed and pollen dispersal rates among plant populations.

    Science.gov (United States)

    Robledo-Arnuncio, J J

    2012-03-01

    There are few statistical methods for estimating contemporary dispersal among plant populations. A maximum-likelihood procedure is introduced here that uses pre- and post-dispersal population samples of biparentally inherited genetic markers to jointly estimate contemporary seed and pollen immigration rates from a set of discrete external sources into a target population. Monte Carlo simulations indicate that accurate estimates and reliable confidence intervals can be obtained using this method for both pollen and seed migration rates at modest sample sizes (100 parents/population and 100 offspring) when population differentiation is moderate (F(ST) ≥ 0.1), or by increasing pre-dispersal samples (to about 500 parents/population) when genetic divergence is weak (F(ST) = 0.01). The method exhibited low sensitivity to the number of source populations and achieved good accuracy at affordable genetic resolution (10 loci with 10 equifrequent alleles each). Unsampled source populations introduced positive biases in migration rate estimates from sampled sources, although they were minor when the proportion of immigration from the latter was comparatively low. A practical application of the method to a metapopulation of the Australian resprouter shrub Banksia attenuata revealed comparable levels of directional seed and pollen migration among dune groups, and the estimate of seed dispersal was higher than a previous estimate based on conservative assignment tests. The method should be of interest to researchers and managers assessing broad-scale nonequilibrium seed and pollen gene flow dynamics in plants.

  14. A plant DNA ligase is an important determinant of seed longevity.

    Science.gov (United States)

    Waterworth, Wanda M; Masnavi, Ghzaleh; Bhardwaj, Rajni M; Jiang, Qing; Bray, Clifford M; West, Christopher E

    2010-09-01

    DNA repair is important for maintaining genome integrity. In plants, DNA damage accumulated in the embryo of seeds is repaired early in imbibition, and is important for germination performance and seed longevity. An essential step in most repair pathways is the DNA ligase-mediated rejoining of single- and double-strand breaks. Eukaryotes possess multiple DNA ligase enzymes, each having distinct roles in cellular metabolism. Here, we report the characterization of DNA LIGASE VI, which is only found in plant species. The primary structure of this ligase shows a unique N-terminal region that contains a β-CASP motif, which is found in a number of repair proteins, including the DNA double-strand break (DSB) repair factor Artemis. Phenotypic analysis revealed a delay in the germination of atlig6 mutants compared with wild-type lines, and this delay becomes markedly exacerbated in the presence of the genotoxin menadione. Arabidopsis atlig6 and atlig6 atlig4 mutants display significant hypersensitivity to controlled seed ageing, resulting in delayed germination and reduced seed viability relative to wild-type lines. In addition, atlig6 and atlig6 atlig4 mutants display increased sensitivity to low-temperature stress, resulting in delayed germination and reduced seedling vigour upon transfer to standard growth conditions. Seeds display a rapid transcriptional DNA DSB response, which is activated in the earliest stages of water imbibition, providing evidence for the accumulation of cytotoxic DSBs in the quiescent seed. These results implicate AtLIG6 and AtLIG4 as major determinants of Arabidopsis seed quality and longevity.

  15. Transcriptome Analysis of Gelatin Seed Treatment as a Biostimulant of Cucumber Plant Growth

    Directory of Open Access Journals (Sweden)

    H. T. Wilson

    2015-01-01

    Full Text Available The beneficial effects of gelatin capsule seed treatment on enhanced plant growth and tolerance to abiotic stress have been reported in a number of crops, but the molecular mechanisms underlying such effects are poorly understood. Using mRNA sequencing based approach, transcriptomes of one- and two-week-old cucumber plants from gelatin capsule treated and nontreated seeds were characterized. The gelatin treated plants had greater total leaf area, fresh weight, frozen weight, and nitrogen content. Pairwise comparisons of the RNA-seq data identified 620 differentially expressed genes between treated and control two-week-old plants, consistent with the timing when the growth related measurements also showed the largest differences. Using weighted gene coexpression network analysis, significant coexpression gene network module of 208 of the 620 differentially expressed genes was identified, which included 16 hub genes in the blue module, a NAC transcription factor, a MYB transcription factor, an amino acid transporter, an ammonium transporter, a xenobiotic detoxifier-glutathione S-transferase, and others. Based on the putative functions of these genes, the identification of the significant WGCNA module and the hub genes provided important insights into the molecular mechanisms of gelatin seed treatment as a biostimulant to enhance plant growth.

  16. Seed germination of medicinal plant, fennel (Foeniculum vulgare Mill), as affected by different priming techniques.

    Science.gov (United States)

    Tahaei, Amirreza; Soleymani, Ali; Shams, Majid

    2016-09-01

    Reduced seed germination is among the most important factors adversely affecting crop stand and subsequent plant growth. Fennel (Foeniculum vulgare Mill) is an important medicinal plant with poor seed germination rate, occasionally. It is accordingly pertinent to find methods which can enhance fennel seed germination and remove the barriers of dormancy breaking. The present experiments studied the effects of two different priming (cold moist stratification and osmopriming) and 14 dormancy breaking techniques (hormonal, osmopriming, biopriming, chemical priming, and hydropriming) on the seed germination and seedling growth of two different fennel genotypes under growth chamber conditions. In the first and second experiment, the priming techniques including the time lengths of cold moist stratification (0, 15, 30, and 45 days) and the concentrations of polyethylene glycol 6000 (PEG6000, osmopriming at -0.99, -1.35, and -2.33 MPa) were used as the main plots. However, in both experiments, the dormancy breaking techniques and fennel genotypes were factorially combined and used as the subplots. Different seed- and seedling-related parameters including germination (%), plumule, radicle and seedling length, average germination time, rate and homogeneity of germination, and seed vigor index were determined. Both priming techniques were efficient on the enhancement of seed germination and seedling growth. Among the dormancy breaking techniques, Aminol Forte (biopriming), kadostim (biopriming), benzyl adenine + kinetin (biopriming), distilled water (hydropriming), gibberellin + kinetin (hormonal priming), and benzyl adenine + kinetin + gibberellin (biopriming) were the most effective ones. The related concentrations were equal to 100 mg/l, 10(-5) M, and 0.4 %. The fennel genotypes reacted significantly different under priming conditions. It is possible to enhance seed germination and seedling growth of fennel using priming and dormancy breaking

  17. Glycinebetaine enhances the tolerance of tomato plants to high temperature during germination of seeds and growth of seedlings.

    Science.gov (United States)

    Li, Shufen; Li, Feng; Wang, Jianwei; Zhang, Wen; Meng, Qingwei; Chen, Tony H H; Murata, Norio; Yang, Xinghong

    2011-11-01

    Tomato (Lycopersicon esculentum cv. 'Moneymaker') was transformed with a codA gene, from Arthrobacter globiformis, for choline oxidase that had been modified to allow targeting to both chloroplasts and the cytosol. Glycinebetaine (GB) accumulated in seeds of transformed plants up to 1 µmol g(-1) dry weight (DW), while no detectable GB was found in wild-type (WT) seeds. The codA-transgenic seeds germinated faster and at higher frequency than WT seeds with high temperature treatment. After heat stress, levels of expression of a mitochondrial small heat-shock protein (MT-sHSP), heat-shock protein 70 (HSP70) and heat-shock cognate 70 (HSC70) were higher in transgenic seeds than in WT seeds during heat stress, and the accumulation of HSP70 was more prominent in codA-transgenic seeds than in WT seeds. Addition of GB to the germination medium or imbibition of seeds in a solution of GB enhanced the tolerance of WT seeds to high temperatures. WT seeds treated with exogenous GB also expressed heat-shock genes at elevated levels and accumulated more HSP70 than controls. Our results suggest that GB, either applied exogenously or accumulated in vivo in codA-transgenic seeds, enhanced the expression of heat-shock genes in and improved the tolerance to high temperature of tomato seeds during germination.

  18. High frequency plant regeneration from mature seed- derived callus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... The overall plant regeneration rates of the examined cultivars ranged from 7.5 to ... MS basal salts and vitamins (Murashige and Skoog. 1962), 500 mg .... and BA examined, MS medium fortified with 5 mg l-1 of. 2,4-D and 0.5 ...

  19. Effects of farmer social status and plant biocultural value on seed circulation networks in Vanuatu

    Directory of Open Access Journals (Sweden)

    Mathieu Thomas

    2016-06-01

    Full Text Available Seed circulation among farmers, which is embedded in composite social networks, is a key process in the dynamics of seed systems that shape crop diversity. We analyzed the daily circulation of biological objects, i.e., cultivated plants (31 species, 284 landraces, within a community of first-generation migrants (16 households, 30 persons living on the island of Vanua Lava in the South Pacific archipelago nation of Vanuatu. By combining participant observation, ethnobiological inventories, and social network analysis, we investigated how farmer social status and plant biocultural value affect plant circulation. Plant biocultural value was estimated by referring to their local classification according to uses, cultivation practices, growing environments, and biological properties. An aggregate plant circulation network (577 events and three subnetworks (i.e., for starchy, side dish, or snack food categories sharing the same 30 nodes were analyzed using exponential random graph models. Evidence that farmer social status influences the patterns of plant circulation was found through the distribution of structural parameters of the network, including: dyadic reciprocity; in-degree, out-degree, and their correlation; triadic cycling; and transitivity. At the scale of the aggregate network, direct or indirect reciprocity was not observed. Instead, a high out-degree (i.e., being a more frequent giver and a negative correlation between in-degree and out-degree both confer prestige and reinforce hierarchy. These results suggest that some of the social dynamics of the Melanesian-type Big Man political system may persist, even though the system itself no longer exists in traditional form. Moreover, based on our comparative analysis of the three subnetworks, farmer social status appears to influence greatly the circulation of plants with high biocultural value while having little influence on plants with low biocultural value. Farmer social status and plant

  20. Endophytic fungal pre-treatments of seeds alleviates salinity stress effects in soybean plants.

    Science.gov (United States)

    Radhakrishnan, Ramalingam; Khan, Abdul Latif; Lee, In-Jung

    2013-12-01

    In the present study, four endophytic fungi (GM-1, GM-2, GM-3, and GM-4) were tested for their ability to improve soybean plant growth under salinity stress conditions. The seed germination and plant growth were higher in seeds pretreated with endophytic fungal cultures than their controls. The positive influence of fungi on plant growth was supported by gibberellins analysis of culture filtrate (CF), which showed wide diversity and various concentrations of GAs. Specifically, GA4, GA7, GA8, GA9, GA12, and GA20 were found in fungal CFs. Under salinity stress conditions, GM-1 significantly enhanced the length and fresh weight of soybean plants relative to other fungal treatments. GM-1 effectively mitigated the adverse effects of salinity by limiting lipid peroxidation and accumulating protein content. GM-2, GM-3, and GM-4 also counteracted the salinity induced oxidative stress in soybean plants through reduction of lipid peroxidation and enhancement of protein content, maintaining the length and fresh weight of shoots. The activities of the antioxidant enzymes catalase, superoxide dismutase and peroxidase were inhibited in salinity exposed plants, while GM-1 significantly enhanced these antioxidant enzyme activities in plants under salt stress. GM-1 treatment also showed lower levels of abscisic acid and elevated levels of salicylic acid in plants under salinity stress. Hence, GM-1 was identified as Fusarium verticillioides (teleomorph Gibberella moniliformis) isolate RK01 based on its DNA sequence homology. These results suggest that endophytic fungal (F. verticillioides) pre-treatment of soybean seeds would be an effective method to promote soybean plant growth under salinity stress conditions.

  1. Imprinting in plants as a mechanism to generate seed phenotypic diversity

    Directory of Open Access Journals (Sweden)

    A Mark eSettles

    2015-01-01

    Full Text Available Normal plant development requires epigenetic regulation to enforce changes in developmental fate. Genomic imprinting is a type of epigenetic regulation in which identical alleles of genes are expressed in a parent-of-origin dependent manner. Deep sequencing of transcriptomes has identified hundreds of imprinted genes with scarce evidence for the developmental importance of individual imprinted loci. Imprinting is regulated through global DNA demethylation in the central cell prior to fertilization and directed repression of individual loci with the Polycomb Repressive Complex 2 (PRC2. There is significant evidence for transposable elements and repeat sequences near genes acting as cis-elements to determine imprinting status of a gene, implying that imprinted gene expression patterns may evolve randomly and at high frequency. Detailed genetic analysis of a few imprinted loci suggests an imprinted pattern of gene expression is often dispensable for seed development. Few genes show conserved imprinted expression within or between plant species. These data are not fully explained by current models for the evolution of imprinting in plant seeds. We suggest that imprinting may have evolved to provide a mechanism for rapid neofunctionalization of genes during seed development to increase phenotypic diversity of seeds.

  2. Soybean morphophysiology and yield response to seeding systems and plant populations

    Directory of Open Access Journals (Sweden)

    Raniele Souza

    2016-03-01

    Full Text Available Soybean (Glicine max [L.] Merr. is recognized worldwide for its economic importance; it has the ability to adapt to environmental and management changes, particularly when using different spacing and plant populations. This study aimed to investigate the influence of morphological changes of the crisscross seeding system on grain growth and yield. Work was conducted at the Experimental Station of Anapolis, Goiás, Brazil, of the Technical Assistance Agency, Rural Extension and Agricultural Research of Goiás (EMATER for the 2013-2014 harvest. The experimental design was a randomized block and 2 x 3 x 3 factorial, with four replicates. Treatments consisted of two seeding systems (conventional-in line and crossed-crisscross, three soybean cultivars with different growth habits ('BRS Valiosa RR' determined, 'NA 7337 RR' semi-determined, and 'BMX Potencia RR' indeterminate and three sowing densities (245 000, 350 000, and 455 000 plants ha-1. Results showed that at 50 d after emergence the cross-seeding system showed higher closing among lines promoted by the increase in population. Leaf area and the leaf area index were not affected by the seeding system. Leaf area was lower with increasing plant density with no significant difference in relation to the leaf area index. The cross-system enabled a potential yield of 4504 kg ha-1 corresponding to an approximate 8% increase compared with conventional sowing using equidistant lines with 0.5 m spacing.

  3. The influence of row width and seed spacing on uniformity of plant spatial distributions

    DEFF Research Database (Denmark)

    Griepentrog, Hans W.; Olsen, Jannie Maj; Weiner, Jacob

    2009-01-01

    Crop performance and weed suppression increase with increasing crop spatial uniformity. We use spatial pattern simulations and field experiments to show the current state-of-the-art for spatial uniformity for different seeding technologies. We use Morisita's Index to quantify how changes in row...... width and evenness of spacing within rows influences two-dimensional spatial quality. The results can be used to define new requirements for improved seeding technologies to achieve higher benefits in sustainable crop production systems. In general it can be concluded that more even plant distributions...

  4. A Novel Atmospheric Pressure Plasma Fluidized Bed and Its Application in Mutation of Plant Seeds

    Institute of Scientific and Technical Information of China (English)

    CHEN Guang-Liang; WANG Zhen-Quan; HAN Er-Li; FU Ya-Bo; YANG Si-Ze; FAN Song-Hua; LI Chun-Ling; GU Wei-Chao; FENG Wen-Ran; ZHANG Gu-Ling; WANG Jiu-Li; Latif K.; ZHANG Shu-Gen

    2005-01-01

    @@ An atmospheric pressure plasma fluidized bed (APPFB) is designed to generate plasma using a dielectric barrier discharge (DBD) with one liquid electrode. In the APPFB system, the physical properties of DBD discharge and its application in plant-seed mutating are studied fundamentally. The results show that the generated plasma is a typical glow discharge free from filament and arc plasma, and the macro-temperature of the plasma fluidized bed is nearly at room temperature. There are no obvious changes in the pimientos when their seeds are treated by APPFB, but great changes are found for coxcombs.

  5. Seed sprout production: Consumables and a foundation for higher plant growth in space

    Science.gov (United States)

    Day, Michelle; Thomas, Terri; Johnson, Steve; Luttges, Marvin

    1990-01-01

    Seed sprouts can be produced as a source of fresh vegetable materials and as higher plant seedlings in space. Sprout production was undertaken to evaluate the mass accumulations possible, the technologies needed, and the reliability of the overall process. Baseline experiments corroborated the utility of sprout production protocols for a variety of seed types. The automated delivery of saturated humidity effectively supplants labor intensive manual soaking techniques. Automated humidification also lend itself to modest centrifugal sprout growth environments. A small amount of ultraviolet radiation effectively suppressed bacterial and fungal contamination, and the sprouts were suitable for consumption.

  6. How detrimental are seed galls to their hosts? Plant performance, germination, developmental instability and tolerance to herbivory in Inga laurina, a leguminous tree.

    Science.gov (United States)

    Santos, J C; de Araujo, N A V; Venâncio, H; Andrade, J F; Alves-Silva, E; Almeida, W R; Carmo-Oliveira, R

    2016-11-01

    Gall inducers use these structures as shelters and sources of nutrition. Consequently, they cause multiple physiological changes in host plants. We studied the impact caused by seed coat galls of a braconid wasp on the performance of fruits, seeds and seedlings of tree Inga laurina. We tested whether these seed galls are 'nutrient sinks' with respect to the fruit/seed of host plant, and so constrain the reproductive ability and reduce seedling longevity. We measured the influence of such galls on the secondary compounds, fruit and seed parameters, seed viability and germination and seedling performance. Inga laurina has indehiscent legumes with polyembryonic seeds surrounded by a fleshy sarcotesta rich in sugars. The galls formed inside the seed coat and galled tissues presented higher phenol concentrations, around 7-fold that of ungalled tissues. Galls caused a significant reduction in parameters such as fruit and seed size, seed weight and the number of embryos. Fluctuating asymmetry (a stress indicator) was 31% higher in leaves of galled seed plants in comparison to ungalled seed plants. However, the negative effects on fruit and seed parameters were not sufficient to reduce seed germination (except the synchronization index) or seedling performance (except leaf area and chlorophyll content). We attributed these results to the ability of I. laurina to tolerate gall attack on seeds without a marked influence on seedling performance. Moreover, because of the intensity of seed galling on host plant, we suggest that polyembryony may play a role in I. laurina reproduction increasing tolerance to seed damage.

  7. Bioluminescence Imaging of Clavibacter michiganensis subsp. michiganensis Infection of Tomato Seeds and Plants

    Science.gov (United States)

    Xu, Xiulan; Miller, Sally A.; Baysal-Gurel, Fulya; Gartemann, Karl-Heinz; Eichenlaub, Rudolf; Rajashekara, Gireesh

    2010-01-01

    Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes wilting and cankers, leading to severe economic losses in commercial tomato production worldwide. The disease is transmitted from infected seeds to seedlings and mechanically from plant to plant during seedling production, grafting, pruning, and harvesting. Because of the lack of tools for genetic manipulation, very little is known regarding the mechanisms of seed and seedling infection and movement of C. michiganensis subsp. michiganensis in grafted plants, two focal points for application of bacterial canker control measures in tomato. To facilitate studies on the C. michiganensis subsp. michiganensis movement in tomato seed and grafted plants, we isolated a bioluminescent C. michiganensis subsp. michiganensis strain using the modified Tn1409 containing a promoterless lux reporter. A total of 19 bioluminescent C. michiganensis subsp. michiganensis mutants were obtained. All mutants tested induced a hypersensitive response in Mirabilis jalapa and caused wilting of tomato plants. Real-time colonization studies of germinating seeds using a virulent, stable, constitutively bioluminescent strain, BL-Cmm17, showed that C. michiganensis subsp. michiganensis aggregated on hypocotyls and cotyledons at an early stage of germination. In grafted seedlings in which either the rootstock or scion was exposed to BL-Cmm17 via a contaminated grafting knife, bacteria were translocated in both directions from the graft union at higher inoculum doses. These results emphasize the use of bioluminescent C. michiganensis subsp. michiganensis to help better elucidate the C. michiganensis subsp. michiganensis-tomato plant interactions. Further, we demonstrated the broader applicability of this tool by successful transformation of C. michiganensis subsp. nebraskensis with Tn1409::lux. Thus, our approach would be highly useful to understand the pathogenesis of diseases caused by other subspecies of the

  8. Bioluminescence imaging of Clavibacter michiganensis subsp. michiganensis infection of tomato seeds and plants.

    Science.gov (United States)

    Xu, Xiulan; Miller, Sally A; Baysal-Gurel, Fulya; Gartemann, Karl-Heinz; Eichenlaub, Rudolf; Rajashekara, Gireesh

    2010-06-01

    Clavibacter michiganensis subsp. michiganensis is a Gram-positive bacterium that causes wilting and cankers, leading to severe economic losses in commercial tomato production worldwide. The disease is transmitted from infected seeds to seedlings and mechanically from plant to plant during seedling production, grafting, pruning, and harvesting. Because of the lack of tools for genetic manipulation, very little is known regarding the mechanisms of seed and seedling infection and movement of C. michiganensis subsp. michiganensis in grafted plants, two focal points for application of bacterial canker control measures in tomato. To facilitate studies on the C. michiganensis subsp. michiganensis movement in tomato seed and grafted plants, we isolated a bioluminescent C. michiganensis subsp. michiganensis strain using the modified Tn1409 containing a promoterless lux reporter. A total of 19 bioluminescent C. michiganensis subsp. michiganensis mutants were obtained. All mutants tested induced a hypersensitive response in Mirabilis jalapa and caused wilting of tomato plants. Real-time colonization studies of germinating seeds using a virulent, stable, constitutively bioluminescent strain, BL-Cmm17, showed that C. michiganensis subsp. michiganensis aggregated on hypocotyls and cotyledons at an early stage of germination. In grafted seedlings in which either the rootstock or scion was exposed to BL-Cmm17 via a contaminated grafting knife, bacteria were translocated in both directions from the graft union at higher inoculum doses. These results emphasize the use of bioluminescent C. michiganensis subsp. michiganensis to help better elucidate the C. michiganensis subsp. michiganensis-tomato plant interactions. Further, we demonstrated the broader applicability of this tool by successful transformation of C. michiganensis subsp. nebraskensis with Tn1409::lux. Thus, our approach would be highly useful to understand the pathogenesis of diseases caused by other subspecies of the

  9. Evaluating the Interacting Influences of Pollination, Seed Predation, Invasive Species and Isolation on Reproductive Success in a Threatened Alpine Plant

    Science.gov (United States)

    Krushelnycky, Paul D.

    2014-01-01

    Reproduction in rare plants may be influenced and limited by a complex combination of factors. External threats such as invasive species and landscape characteristics such as isolation may impinge on both pollination and seed predation dynamics, which in turn can strongly affect reproduction. I assessed how patterns in floral visitation, seed predation, invasive ant presence, and plant isolation influenced one another and ultimately affected viable seed production in Haleakalā silverswords (Argyroxiphium sandwicense subsp. macrocephalum) of Hawai’i. Floral visitation was dominated by endemic Hylaeus bees, and patterns of visitation were influenced by floral display size and number of plants clustered together, but not by floral herbivory or nearest flowering neighbor distance. There was also some indication that Argentine ant presence impacted floral visitation, but contradictory evidence and limitations of the study design make this result uncertain. Degree of seed predation was associated only with plant isolation, with the two main herbivores partitioning resources such that one preferentially attacked isolated plants while the other attacked clumped plants; total seed predation was greater in more isolated plants. Net viable seed production was highly variable among individuals (0–55% seed set), and was affected mainly by nearest neighbor distance, apparently owing to low cross-pollination among plants separated by even short distances (>10–20 m). This isolation effect dominated net seed set, with no apparent influence from floral visitation rates, percent seed predation, or invasive ant presence. The measured steep decline in seed set with isolation distance may not be typical of the entire silversword range, and may indicate that pollinators in addition to Hylaeus bees could be important for greater gene flow. Management aimed at maintaining or maximizing silversword reproduction should focus on the spatial context of field populations and outplanting

  10. Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station

    Science.gov (United States)

    Tepfer, David; Leach, Sydney

    2017-03-01

    For life to survive outside the biosphere, it must be protected from UV light and other radiation by exterior shielding or through sufficient inherent resistance to survive without protection. We tested the plausibility of inherent resistance in plant seeds, reporting in a previous paper that Arabidopsis thaliana and tobacco (Nicotiana tabacum) seeds exposed for 558 days outside the International Space Station (ISS) germinated and developed into fertile plants after return to Earth. We have now measured structural genetic damage in tobacco seeds from this EXPOSE-E experiment by quantitatively amplifying a segment of an antibiotic resistance gene, nptII, inserted into the chloroplast genome. We also assessed the survival of the antibiotic resistance encoded by nptII, using marker rescue in a soil bacterium. Chloroplast DNA damage occurred, but morphological mutants were not detected among the survivors. In a second, longer mission (EXPOSE-R), a nearly lethal exposure was received by Arabidopsis seeds. Comparison between a ground simulation, lacking UVresistance in long-lived, larger seeds, we exposed Arabidopsis, tobacco, and morning glory seeds in the laboratory to doses of UV254nm, ranging as high as 2420 MJ m-2. Morning glory seeds resisted this maximum dose, which killed tobacco and Arabidopsis. We thus confirm that a naked plant seed could survive UV exposures during direct transfer from Mars to Earth and suggest that seeds with a more protective seed coat (e.g., morning glory) should survive much longer space travel.

  11. Fermentation of aqueous plant seed extracts by lactic acid bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Schafner, D.W.; Beuchat, R.L.

    1986-05-01

    The effects of lactic acid bacterial fermentation on chemical and physical changes in aqueous extracts of cowpea (Vigna unguiculata), peanut (Arachis hypogea), soybean (Glycine max), and sorghum (Sorghum vulgare) were studied. The bacteria investigated were Lactobacillus helveticus, L. delbrueckii, L. casei, L. bulgaricus, L. acidophilus, and Streptococcus thermophilus. Organisms were inoculated individually into all of the seed extracts; L. bulgaricus and S. thermophilus were also evaluated together as inocula for fermenting the legume extracts. During fermentation, bacterial population and changes in titratable acidity, pH, viscosity, and color were measured over a 72 h period at 37 degrees C. Maximum bacterial populations, titratable acidity, pH, and viscosity varied depending upon the type of extract and bacterial strain. The maximum population of each organism was influenced by fermentable carbohydrates, which, in turn, influenced acid production and change in pH. Change in viscosity was correlated with the amount of protein and titratable acidity of products. Color was affected by pasteurization treatment and fermentation as well as the source of extract. In the extracts inoculated simultaneously with L. bulgaricus and S. thermophilus, a synergistic effect resulted in increased bacterial populations, titratable acidity, and viscosity, and decreased pH in all the legume extracts when compared to the extracts fermented with either of these organisms individually. Fermented extracts offer potential as substitutes for cultured dairy products. 24 references.

  12. A Switch in Keystone Seed-Dispersing Ant Genera between Two Elevations for a Myrmecochorous Plant, Acacia terminalis.

    Science.gov (United States)

    Thomson, Fiona J; Auld, Tony D; Ramp, Daniel; Kingsford, Richard T

    2016-01-01

    The dispersal capacity of plant species that rely on animals to disperse their seeds (biotic dispersal) can alter with changes to the populations of their keystone dispersal vectors. Knowledge on how biotic dispersal systems vary across landscapes allows better understanding of factors driving plant persistence. Myrmecochory, seed dispersal by ants, is a common method of biotic dispersal for many plant species throughout the world. We tested if the seed dispersal system of Acacia terminalis (Fabaceae), a known myrmecochore, differed between two elevations in the Greater Blue Mountains World Heritage Area, in southeastern Australia. We compared ant assemblages, seed removal rates of ants and other vertebrates (bird and mammal) and the dominant seed-dispersing ant genera. At low elevations (c. 200 m a.s.l) seed removal was predominantly by ants, however, at high elevation sites (c. 700 m a.s.l) vertebrate seed dispersers or seed predators were present, removing over 60% of seeds from experimental depots when ants were excluded. We found a switch in the keystone seed-dispersing ant genera from Rhytidoponera at low elevations sites to Aphaenogaster at high elevation sites. This resulted in more seeds being removed faster at low elevation sites compared to high elevation sites, however long-term seed removal rates were equal between elevations. Differences in the keystone seed removalist, and the addition of an alternate dispersal vector or seed predator at high elevations, will result in different dispersal and establishment patterns for A. terminalis at different elevations. These differences in dispersal concur with other global studies that report myrmecochorous dispersal systems alter with elevation.

  13. A Switch in Keystone Seed-Dispersing Ant Genera between Two Elevations for a Myrmecochorous Plant, Acacia terminalis.

    Directory of Open Access Journals (Sweden)

    Fiona J Thomson

    Full Text Available The dispersal capacity of plant species that rely on animals to disperse their seeds (biotic dispersal can alter with changes to the populations of their keystone dispersal vectors. Knowledge on how biotic dispersal systems vary across landscapes allows better understanding of factors driving plant persistence. Myrmecochory, seed dispersal by ants, is a common method of biotic dispersal for many plant species throughout the world. We tested if the seed dispersal system of Acacia terminalis (Fabaceae, a known myrmecochore, differed between two elevations in the Greater Blue Mountains World Heritage Area, in southeastern Australia. We compared ant assemblages, seed removal rates of ants and other vertebrates (bird and mammal and the dominant seed-dispersing ant genera. At low elevations (c. 200 m a.s.l seed removal was predominantly by ants, however, at high elevation sites (c. 700 m a.s.l vertebrate seed dispersers or seed predators were present, removing over 60% of seeds from experimental depots when ants were excluded. We found a switch in the keystone seed-dispersing ant genera from Rhytidoponera at low elevations sites to Aphaenogaster at high elevation sites. This resulted in more seeds being removed faster at low elevation sites compared to high elevation sites, however long-term seed removal rates were equal between elevations. Differences in the keystone seed removalist, and the addition of an alternate dispersal vector or seed predator at high elevations, will result in different dispersal and establishment patterns for A. terminalis at different elevations. These differences in dispersal concur with other global studies that report myrmecochorous dispersal systems alter with elevation.

  14. Consolida regalis Gray seed production as influenced by the habitat and crop plant in the western Podlasie region

    Directory of Open Access Journals (Sweden)

    Teresa Skrajna

    2014-01-01

    Full Text Available Studies were conducted in 2007–2009 in the Western Podlasie region to examine the seed production potential of Consolida regalis under different habitat conditions. Consolida regalis populations from 15 sites representing the habitat amplitude of this species were examined. Thirty morphologically different plants were sampled from each habitat and soil samples were taken to determine soil contents of available phosphorus (P, potassium (K and magnesium (Mg as well as pH. The results were statistically analysed. The seed production potential of the species studied was most strongly correlated with soil contents of magnesium (Mg, potassium (K, phosphorus (P and soil pH. By contrast, the kind of crop plant and its cover were insignificant. Of the plant characteristics, plant height and traits associated with inflorescence structure had a significant influence on seed production potential. The populations with the greatest seed production potential produced an average of 1287 and 965 se- eds per plant. These populations were associated with the most fertile sites (good wheat soil complex where the differences in seed production potential resulted from the nutrient contents and soil pH. By contrast, the least seeds were produced by plants growing on poor and acidic light soils. The average seed number per plant ranged from 42 to 83. Low concentrations of the nutrients examined were determined, with the soil content of magnesium being very low.

  15. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant-plant mutualism.

    Science.gov (United States)

    Pringle, Elizabeth G

    2014-06-22

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant-plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output.

  16. Harnessing ant defence at fruits reduces bruchid seed predation in a symbiotic ant–plant mutualism

    Science.gov (United States)

    Pringle, Elizabeth G.

    2014-01-01

    In horizontally transmitted mutualisms, mutualists disperse separately and reassemble in each generation with partners genetically unrelated to those in the previous generation. Because of this, there should be no selection on either partner to enhance the other's reproductive output directly. In symbiotic ant–plant mutualisms, myrmecophytic plants host defensive ant colonies, and ants defend the plants from herbivores. Plants and ants disperse separately, and, although ant defence can indirectly increase plant reproduction by reducing folivory, it is unclear whether ants can also directly increase plant reproduction by defending seeds. The neotropical tree Cordia alliodora hosts colonies of Azteca pittieri ants. The trees produce domatia where ants nest at stem nodes and also at the node between the peduncle and the rachides of the infloresence. Unlike the stem domatia, these reproductive domatia senesce after the tree fruits each year. In this study, I show that the tree's resident ant colony moves into these ephemeral reproductive domatia, where they tend honeydew-producing scale insects and patrol the nearby developing fruits. The presence of ants significantly reduced pre-dispersal seed predation by Amblycerus bruchid beetles, thereby directly increasing plant reproductive output. PMID:24807259

  17. Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability.

    Science.gov (United States)

    Canedo-Júnior, Ernesto Oliveira; Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

    2017-01-01

    Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management.

  18. Isolated and Community Contexts Produce Distinct Responses by Host Plants to the Presence of Ant-Aphid Interaction: Plant Productivity and Seed Viability

    Science.gov (United States)

    Santiago, Graziele Silva; Zurlo, Luana Fonseca; Ribas, Carla Rodrigues; Carvalho, Rafaela Pereira; Alves, Guilherme Pereira; Carvalho, Mariana Comanucci Silva; Souza, Brígida

    2017-01-01

    Ant-aphid interactions may affect host plants in several ways, however, most studies measure only the amount of fruit and seed produced, and do not test seed viability. Therefore, the aim of this study was to assess the effects of the presence of ant-aphid interactions upon host plant productivity and seed viability in two different contexts: isolated and within an arthropod community. For this purpose we tested the hypothesis that in both isolated and community contexts, the presence of an ant-aphid interaction will have a positive effect on fruit and seed production, seed biomass and rate of seed germination, and a negative effect on abnormal seedling rates, in comparison to plants without ants. We performed a field mesocosm experiment containing five treatments: Ant-aphid, Aphid, Community, Ant-free community and Control. We counted fruits and seeds produced by each treatment, and conducted experiments for seed biomass and germinability. We found that in the community context the presence of an ant-aphid interaction negatively affected fruit and seed production. We think this may be because aphid attendance by tending-ants promotes aphid damage to the host plant, but without an affect on seed weight and viability. On the other hand, when isolated, the presence of an ant-aphid interaction positively affected fruit and seed production. These positive effects are related to the cleaning services offered to aphids by tending-ants, which prevent the development of saprophytic fungi on the surface of leaves, which would cause a decrease in photosynthetic rates. Our study is important because we evaluated some parameters of plant fitness that have not been addressed very well by other studies involving the effects of ant-aphid interactions mainly on plants with short life cycles. Lastly, our context dependent approach sheds new light on how ecological interactions can vary among different methods of crop management. PMID:28141849

  19. Why would plant species become extinct locally if growing conditions improve?

    NARCIS (Netherlands)

    Kramer, K.; Bijlsma, R.J.; Hickler, T.; Thuiller, W.

    2012-01-01

    Two assumptions underlie current models of the geographical ranges of perennial plant species: 1. current ranges are in equilibrium with the prevailing climate, and 2. changes are attributable to changes in macroclimatic factors, including tolerance of winter cold, the duration of the growing season

  20. Preparation and testing of plant seed meal-based wood adhesives.

    Science.gov (United States)

    He, Zhongqi; Chapital, Dorselyn C

    2015-01-01

    Recently, the interest in plant seed meal-based products as wood adhesives has steadily increased, as these plant raw materials are considered renewable and environment-friendly. These natural products may serve as alternatives to petroleum-based adhesives to ease environmental and sustainability concerns. This work demonstrates the preparation and testing of the plant seed-based wood adhesives using cottonseed and soy meal as raw materials. In addition to untreated meals, water washed meals and protein isolates are prepared and tested. Adhesive slurries are prepared by mixing a freeze-dried meal product with deionized water (3:25 w/w) for 2 hr. Each adhesive preparation is applied to one end of 2 wood veneer strips using a brush. The tacky adhesive coated areas of the wood veneer strips are lapped and glued by hot-pressing. Adhesive strength is reported as the shear strength of the bonded wood specimen at break. Water resistance of the adhesives is measured by the change in shear strength of the bonded wood specimens at break after water soaking. This protocol allows one to assess plant seed-based agricultural products as suitable candidates for substitution of synthetic-based wood adhesives. Adjustments to the adhesive formulation with or without additives and bonding conditions could optimize their adhesive properties for various practical applications.

  1. The DigitalSeed: an interactive toy for investigating plants

    OpenAIRE

    Cherubini, Mauro; Gash, Hugh; McCloughlin, Thomas

    2010-01-01

    Plant growth, development and reproduction are fundamental concepts in biology; yet there is a recorded lack of motivation for young people to grapple with these concepts. Here we present the ‘DigitalSeed’ toy for making investigations around these concepts more accessible to children through hands-on digital interaction. This is part of an on-going project investigating improved ways of learning involving digital media.To date, this project has addressed the learning of 4-5 year olds, but it...

  2. Evolution of 'smoke' induced seed germination in pyroendemic plants

    Science.gov (United States)

    Keeley, J. E.; Pausas, J.G.

    2016-01-01

    Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

  3. Fruit composition and seed dispersal strategies of woody plants in a Dujiangyan subtropical forest, Southwest China

    Directory of Open Access Journals (Sweden)

    Juan Li

    2013-09-01

    Full Text Available This study aimed to investigate relationships between fruit traits and seed dispersal in a subtropical evergreen broad-leaved forest. Fruit composition and fruit phenology were monitored using 240 seed traps distributed over 10 separated stand patches in a fragmented forest in Dujiangyan City, Sichuan Province, Southwest China. A total of 10,542 mature fruits, belonging to 42 woody plant species of 36 genera and 24 families, were collected between April 2009 and December 2010. The peak of fruiting and fruit abundance occurred during autumn (between September and December when there is less rainfall. Plant families with higher species richness included Fagaceae (17%, Lauraceae (12%, and Rosaceae (10%, while other families included only 1–2 fruiting species. Seed dispersal by animals was the most dominant dispersal mode (88.1% of species while anemochory (wind dispersal was the mode for other species. Seeds of animal-dispersed species were mainly dispersed by frugivorous birds (52.4%, followed by scatter-hoarding rodents (19.0% and frugivorous birds and mammals combined (16.7%. Drupes (48%, nuts (17%, and cones (10% were the most common fruit types. Species with black fruits (39% and red fruits (21% were most common and were dispersed by fruigivorous birds, while species with brown nuts (29% were also common and were mainly dispersed by scatter-hoarding animals. Most fruiting species (64.3% had relatively small fruits (10 mm in diameter were mainly dispersed by wind or rodents. Our study indicates that most of fruiting woody species occur during autumn (later wet season and early dry season and fruit traits of these plants have been adapted by animal-mediated seed dispersal in the Dujiangyan subtropical forest.

  4. Nutritional traits of bean ( Phaseolus vulgaris ) seeds from plants chronically exposed to ozone pollution.

    Science.gov (United States)

    Iriti, Marcello; Di Maro, Antimo; Bernasconi, Silvana; Burlini, Nedda; Simonetti, Paolo; Picchi, Valentina; Panigada, Cinzia; Gerosa, Giacomo; Parente, Augusto; Faoro, Franco

    2009-01-14

    The effect of chronic exposure to ozone pollution on nutritional traits of bean ( Phaseolus vulgaris L. cv. Borlotto Nano Lingua di Fuoco) seeds from plants grown in filtered and nonfiltered open-top chambers (OTCs) has been investigated. Results showed that, among seed macronutrients, ozone significantly raised total lipids, crude proteins, and dietary fiber and slightly decreased total free amino acid content, although with a significant reduction of asparagine, lysine, valine, methionine, and glycine, compensated by a conspicuous augmentation of ornithine and tryptophan. Phytosterol analysis showed a marked increase of beta-sitosterol, stigmasterol, and campesterol in seeds collected from nonfiltered OTCs. With regard to secondary metabolites, ozone exposure induced a slight increase of total polyphenol content, although causing a significant reduction of some flavonols (aglycone kaempferol and its 3-glucoside derivative) and hydroxycinnamates (caffeic, p-coumaric, and sinapic acids). Total anthocyanins decreased significantly, too. Nevertheless, ozone-exposed seeds showed higher antioxidant activity, with higher Trolox equivalent antioxidant capacity (TEAC) values than those measured in seeds collected from filtered air.

  5. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

    Science.gov (United States)

    Espinar, J.L.; Garcia, L.V.; Clemente, L.

    2005-01-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

  6. Seed Selection by the Harvester Ant Pogonomyrmex rugosus (Hymenoptera: Formicidae) in Coastal Sage Scrub: Interactions With Invasive Plant Species.

    Science.gov (United States)

    Briggs, C M; Redak, R A

    2016-08-01

    Harvester ants can be the dominant seed predators on plants by collecting and eating seeds and are known to influence plant communities. Harvester ants are abundant in coastal sage scrub (CSS), and CSS is frequently invaded by several exotic plant species. This study used observations of foraging and cafeteria-style experiments to test for seed species selection by the harvester ant Pogonomyrmex rugosus Emery (Hymenoptera: Formicidae) in CSS. Analysis of foraging behavior showed that P. rugosus carried seeds of exotic Erodium cicutarium (L.) and exotic Brassica tournefortii (Gouan) on 85 and 15% of return trips to the nest (respectively), and only a very few ants carried the native seeds found within the study areas. When compared with the availability of seeds in the field, P. rugosus selected exotic E. cicutarium and avoided both native Encelia farinosa (Torrey & A. Gray) and exotic B. tournefortii. Foraging by P. rugosus had no major effect on the seed bank in the field. Cafeteria-style experiments confirmed that P. rugosus selected E. cicutarium over other available seeds. Native Eriogonum fasciculatum (Bentham) seeds were even less selected than E. farinosa and B. tournefortii.

  7. Effect of Seed Bacterization on Plant Growth Response and Induction of Disease Resistance in Chilli

    Institute of Scientific and Technical Information of China (English)

    Yasmeen Siddiqui; Sariah Meon

    2009-01-01

    This study aimed to examine the induction of disease resistance, and growth response in chilli plants elicited by plant growth promoting endophytic bacteria [Pseudomonas aeruginosa (UPMP3), Burkholderia cepacia (UPMB3), and Serratia marcescens (UPMS3)]. Seed bacterization with UPMP3 and UPMB3 significantly increased peroxidase (PO),polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) activities. This increase corresponded to greater reduction in pre- and post-emergence damping-off caused by Sclerotium rolfsii. UPMS3 alone or as mixture with UPMP3 and UPMB3 did not show any significant reduction in disease incidence. However, all the isolates tested did not inhibit the seed germination and seedling establishment in chilli.

  8. Dye-sensitized solar cells with natural dyes extracted from plant seeds

    Science.gov (United States)

    El-Ghamri, Hatem S.; El-Agez, Taher M.; Taya, Sofyan A.; Abdel-Latif, Monzir S.; Batniji, Amal Y.

    2014-12-01

    The application of natural dyes extracted from plant seeds in the fabrication of dye-sensitized solar cells (DSSCs) has been explored. Ten dyes were extracted from different plant seeds and used as sensitizers for DSSCs. The dyes were characterized using UV-Vis spectrophotometry. DSSCs were prepared using TiO2 and ZnO nanostructured mesoporous films. The highest conversion efficiency of 0.875 % was obtained with an allium cepa (onion) extract-sensitized TiO2 solar cell. The process of TiO2-film sintering was studied and it was found that the sintering procedure significantly affects the response of the cell. The short circuit current of the DSSC was found to be considerably enhanced when the TiO2 semiconducting layer was sintered gradually.

  9. Hydrology, shore morphology and species traits affect seed dispersal, germination and community assembly in shoreline plant communities

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Sarneel, J.M.; van Paassen, José; Rip, W.J.; Bakker, E.S.

    2014-01-01

    Summary 1.Seed dispersal and germination are two primary processes influencing plant community assembly. On freshwater shores, water levels regulate both processes. However, it is still unclear how water levels, shore morphology and species traits interactively affect seed dispersal and germination,

  10. Relative attractiveness of seeds of myrmecochorous Australian and South African plants to ants, and the chemical basis of this attraction

    CSIR Research Space (South Africa)

    Midgley, JJ

    1995-08-01

    Full Text Available The responses of an indigenous acid an exotic (South American) ant was compared to seeds from exotic (Australian) and indigenous Caps myrmecochorous plants. Non-South African ants were more attracted to seeds of myrmecochorous species, than to non...

  11. Do ungulates facilitate native and exotic plant spread? Seed dispersal by cattle, elk and deer in northeastern Oregon

    Science.gov (United States)

    Anne M. Bartuszevige; Bryan A. Endress

    2008-01-01

    Large domestic and native ungulates have the potential to disperse large quantities of seeds throughout the landscape. Many studies have found that ungulates are capable of dispersing seeds but few quantify the relative importance of ungulate dispersal across the landscape. We investigated the potential for cattle, elk, and deer to disperse native and exotic plants in...

  12. Pollination and seed dispersal of Aquilaria sinensis (Lour. Gilg (Thymelaeaceae: An economic plant species with extremely small populations in China

    Directory of Open Access Journals (Sweden)

    Gao Chen

    2016-10-01

    Full Text Available Pollination and seed dispersal in angiosperms have long been investigated in order to understand the coevolution of plants and animals. However, the signals from flowers and/or seeds to attract pollinators and/or seed dispersers have received comparatively little attention. In this study, the pollination biology and seed dispersal of the vulnerable agarwood plant Aquilaria sinensis (Lour. Gilg, a traditional medicinal plant in China, was studied in its natural distribution range. The reproductive tactics of A. sinensis were studied in detail by employing various tests dealing with fruit set and also seed dispersal. Dynamic headspace extraction followed by GC-MS analysis was also performed in order to reveal the composition of floral scent. The results showed that noctuids and pyralids are the most effective pollinators of pollinator-dependent A. sinensis. The main compounds of the floral scent were (E, E-α-Farnesene (61.9 ± 3.2%, trans-Ocimene (16.6 ± 1.2%, and Benzyl salicylate (4.6 ± 1.1%. The results obtained from seed dispersal experiments indicate that hornets are effective seed dispersers and they may play an important role in long-distance seed dispersal of A. sinensis. Based on our findings, we recommend several protection methods for this threatened agarwood plant in China.

  13. Yield and financial performance estimates of four elite loblolly pine seed sources planted in the Western Gulf Region

    Science.gov (United States)

    Michael A. Blazier; A. Gordon Holley

    2015-01-01

    Eastern seed sources of loblolly pine (Pinus taeda L.) have been planted in the Western Gulf region for nearly three decades because they often have higher growth rates than local seed sources. However, productivity gains for eastern families are sometimes offset by poorer survival rates relative to local families.

  14. Mycorrhizal fungi of Vanilla: diversity, specificity and effects on seed germination and plant growth.

    Science.gov (United States)

    Porras-Alfaro, Andrea; Bayman, Paul

    2007-01-01

    Mycorrhizal fungi are essential for the germination of orchid seeds. However, the specificity of orchids for their mycorrhizal fungi and the effects of the fungi on orchid growth are controversial. Mycorrhizal fungi have been studied in some temperate and tropical, epiphytic orchids, but the symbionts of tropical, terrestrial orchids are still unknown. Here we study diversity, specificity and function of mycorrhizal fungi in Vanilla, a pantropical genus that is both terrestrial and epiphytic. Mycorrhizal roots were collected from four Vanilla species in Puerto Rico, Costa Rica and Cuba. Cultured and uncultured mycorrhizal fungi were identified by sequencing the internal transcribed spacer region of nuclear rDNA (nrITS) and part of the mitochondrial ribosomal large subunit (mtLSU), and by counting number of nuclei in hyphae. Vanilla spp. were associated with a wide range of mycorrhizal fungi: Ceratobasidium, Thanatephorus and Tulasnella. Related fungi were found in different species of Vanilla, although at different relative frequencies. Ceratobasidium was more common in roots in soil and Tulasnella was more common in roots on tree bark, but several clades of fungi included strains from both substrates. Relative frequencies of genera of mycorrhizal fungi differed significantly between cultured fungi and those detected by direct amplification. Ceratobasidium and Tulasnella were tested for effects on seed germination of Vanilla and effects on growth of Vanilla and Dendrobium plants. We found significant differences among fungi in effects on seed germination and plant growth. Effects of mycorrhizal fungi on Vanilla and Dendrobium were similar: a clade of Ceratobasidium had a consistently positive effect on plant growth and seed germination. This clade has potential use in germination and propagation of orchids. Results confirmed that a single orchid species can be associated with several mycorrhizal fungi with different functional consequences for the plant.

  15. Relative importance of water, energy, and heterogeneity in determining regional pteridophyte and seed plant richness in China

    Institute of Scientific and Technical Information of China (English)

    Sheng-Bin CHEN; Gao-Ming JIANG; Zhi-Yun OUYANG; Wei-Hua XU; Yi XIAO

    2011-01-01

    Environmental variables, such as ambient energy, water availability, and environmental heterogeneity have been frequently proposed to account for species diversity gradients. How taxon-specific functional traits define large-scale richness gradients is a fundamental issue in understanding spatial patterns of species diversity, but has not been well documented. Using a large dataset on the regional flora from China, we examine the contrast spatial patterns and environmental determinants between pteridophytes and seed plants which differ in dispersal capacity and environmental requirements. Pteridophyte richness shows more pronounced spatial variation and stronger environmental associations than seed plant richness. Water availability generally accounts for more spatial variance in species richness of pteridophytes and seed plants than energy and heterogeneity do, especially for pteridophytes which have high dependence on moist and shady environments. Thus, pteridophyte richness is disproportionally affected by water-related variables; this in turn results in a higher proportion of pteridophytes in regional vascular plant floras (pteridophyte proportion) in wet regions. Most of the variance in seed plant richness, pteridophyte richness, and pteridophyte proportion explained by energy is included in variation that water and heterogeneity account for, indicating the redundancy of energy in the study extent. However, heterogeneity is more important for determining seed plant distributions. Pteridophyte and seed plant richness is strongly correlated, even after the environmental effects have been removed, implying functional linkages between them. Our study highlights the importance of incorporating biological traits of different taxonomic groups into the studies of macroecology and global change biology.

  16. Differential effect of metals/metalloids on the growth and element uptake of mesquite plants obtained from plants grown at a copper mine tailing and commercial seeds.

    Science.gov (United States)

    Haque, N; Peralta-Videa, J R; Duarte-Gardea, M; Gardea-Torresdey, J L

    2009-12-01

    The selection of appropriate seeds is essential for the success of phytoremediation/restoration projects. In this research, the growth and elements uptake by the offspring of mesquite plants (Prosopis sp.) grown in a copper mine tailing (site seeds, SS) and plants derived from vendor seeds (VS) was investigated. Plants were grown in a modified Hoagland solution containing a mixture of Cu, Mo, Zn, As(III) and Cr(VI) at 0, 1, 5 and 10 mg L(-1) each. After one week, plants were harvested and the concentration of elements was determined by using ICP-OES. At 1 mg L(-1), plants originated from SS grew faster and longer than control plants (0 mg L(-1)); whereas plants grown from VS had opposite response. At 5 mg L(-1), 50% of the plants grown from VS did not survive, while plants grown from SS had no toxicity effects on growth. Finally, plants grown from VS did not survive at 10 mg L(-1) treatment, whilst 50% of the plants grown from SS survived. The ICP-OES data demonstrated that at 1 mg L(-1) the concentration of all elements in SS plants was significantly higher compared to control plants and VS plants. While at 5 mg L(-1), the shoots of SS plants had significantly more Cu, Mo, As, and Cr. The results suggest that SS could be a better source of plants intended to be used for phytoremediation of soil impacted with Cu, Mo, Zn, As and Cr.

  17. Endozoochorical plant seed dispersal by red deer (Cervus elaphus)in the Pol'ana Biosphere Reserve, Slovakia

    NARCIS (Netherlands)

    Steyaert, S.M.J.G.; Bokdam, J.; Braakhekke, W.G.; Find'o, S.

    2009-01-01

    From an evolutionary point of view, endozoochory can be considered as a¿mutualistic process, in which both the plant seed- dispersing animal species and the dispersed plant species benefit. Disperser benefits may be direct, by using the dispersed plant species as a¿food source, and indirect, by

  18. A potent antimicrobial protein from onion seeds showing sequence homology to plant lipid transfer proteins.

    Science.gov (United States)

    Cammue, B P; Thevissen, K; Hendriks, M; Eggermont, K; Goderis, I J; Proost, P; Van Damme, J; Osborn, R W; Guerbette, F; Kader, J C

    1995-10-01

    An antimicrobial protein of about 10 kD, called Ace-AMP1, was isolated from onion (Allium cepa L.) seeds. Based on the near-complete amino acid sequence of this protein, oligonucleotides were designed for polymerase chain reaction-based cloning of the corresponding cDNA. The mature protein is homologous to plant nonspecific lipid transfer proteins (nsLTPs), but it shares only 76% of the residues that are conserved among all known plant nsLTPs and is unusually rich in arginine. Ace-AMP1 inhibits all 12 tested plant pathogenic fungi at concentrations below 10 micrograms mL-1. Its antifungal activity is either not at all or is weakly affected by the presence of different cations at concentrations approximating physiological ionic strength conditions. Ace-AMP1 is also active on two Gram-positive bacteria but is apparently not toxic for Gram-negative bacteria and cultured human cells. In contrast to nsLTPs such as those isolated from radish or maize seeds, Ace-AMP1 was unable to transfer phospholipids from liposomes to mitochondria. On the other hand, lipid transfer proteins from wheat and maize seeds showed little or no antimicrobial activity, whereas the radish lipid transfer protein displayed antifungal activity only in media with low cation concentrations. The relevance of these findings with regard to the function of nsLTPs is discussed.

  19. A new selective medium for isolation of Clavibacter michiganensis subsp. michiganensis from tomato plants and seed.

    Science.gov (United States)

    Ftayeh, Radwan M; von Tiedemann, Andreas; Rudolph, Klaus W E

    2011-11-01

    A new selective and highly sensitive medium was developed for isolation of Clavibacter michiganensis subsp. michiganensis (Cmm), the causal agent of bacterial canker of tomato, from seed and latently infected plants. The new medium (BCT) proved to be superior to all published semiselective media for Cmm and is denoted as selective medium because of (i) its mean plating efficiency, amounting to ≤89% within 7 days for all 30 Cmm strains from different sources tested; (ii) the high selectivity, because accompanying bacterial species occurring on tomato plants and seed or bacteria obtained from culture collections were inhibited to an extent of 98 to 100%; and (iii) the remarkable detection sensitivity. Thus, 8 CFU of Cmm in field plant homogenates containing 12,750 CFU of accompanying saprophytes were detected on BCT. Under these extreme conditions, all of the published semiselective media (D2, KBT, D2ANX, SCM, mSCM, CMM1, mCNS, and EPPO) gave false-negative results. Either some media were rather toxic and Cmm growth was also inhibited or the other, less toxic media allowed growth of high numbers of saprophytes, so that Cmm growth was suppressed. Exclusively, BCT also supported growth of the closely related C. michiganensis subsp. insidiosus, nebraskensis, and tessellarius. The new medium is recommended for Cmm detection in tomato seed, and in symptomless tomato plantlets, to improve disease control of bacterial canker of tomato.

  20. Handling Arabidopsis plants: growth, preservation of seeds, transformation, and genetic crosses.

    Science.gov (United States)

    Rivero, Luz; Scholl, Randy; Holomuzki, Nicholas; Crist, Deborah; Grotewold, Erich; Brkljacic, Jelena

    2014-01-01

    Growing healthy plants is essential for the advancement of Arabidopsis thaliana (Arabidopsis) research. Over the last 20 years, the Arabidopsis Biological Resource Center (ABRC) has collected and developed a series of best-practice protocols, some of which are presented in this chapter. Arabidopsis can be grown in a variety of locations, growth media, and environmental conditions. Most laboratory accessions and their mutant or transgenic derivatives flower after 4-5 weeks and set seeds after 7-8 weeks, under standard growth conditions (soil, long day, 23 ºC). Some mutant genotypes, natural accessions, and Arabidopsis relatives require strict control of growth conditions best provided by growth rooms, chambers, or incubators. Other lines can be grown in less-controlled greenhouse settings. Although the majority of lines can be grown in soil, certain experimental purposes require utilization of sterile solid or liquid growth media. These include the selection of primary transformants, identification of homozygous lethal individuals in a segregating population, or bulking of a large amount of plant material. The importance of controlling, observing, and recording growth conditions is emphasized and appropriate equipment required to perform monitoring of these conditions is listed. Proper conditions for seed harvesting and preservation, as well as seed quality control, are also described. Plant transformation and genetic crosses, two of the methods that revolutionized Arabidopsis genetics, are introduced as well.

  1. Genotype by environment interaction for seed yield per plant in rapeseed using AMMI model

    Directory of Open Access Journals (Sweden)

    Ana Marjanović-Jeromela

    2011-02-01

    Full Text Available The objective of this study was to assess genotype by environment interaction for seed yield per plant in rapeseed cultivars grown in Northern Serbia by the AMMI (additive main effects and multiplicative interaction model. The study comprised 19 rapeseed genotypes, analyzed in seven years through field trials arranged in a randomized complete block design, with three replicates. Seed yield per plant of the tested cultivars varied from 1.82 to 19.47 g throughout the seven seasons, with an average of 7.41 g. In the variance analysis, 72.49% of the total yield variation was explained by environment, 7.71% by differences between genotypes, and 19.09% by genotype by environment interaction. On the biplot, cultivars with high yield genetic potential had positive correlation with the seasons with optimal growing conditions, while the cultivars with lower yield potential were correlated to the years with unfavorable conditions. Seed yield per plant is highly influenced by environmental factors, which indicates the adaptability of specific genotypes to specific seasons.

  2. Maternal control of nutrient allocation in plant seeds by genomic imprinting.

    Science.gov (United States)

    Costa, Liliana M; Yuan, Jing; Rouster, Jacques; Paul, Wyatt; Dickinson, Hugh; Gutierrez-Marcos, Jose F

    2012-01-24

    Imprinted genes are commonly expressed in mammalian placentas and in plant seed endosperms, where they exhibit preferential uniparental allelic expression. In mammals, imprinted genes directly regulate placental function and nutrient distribution from mother to fetus; however, none of the >60 imprinted genes thus far reported in plants have been demonstrated to play an equivalent role in regulating the flow of resources to the embryo. Here we show that imprinted Maternally expressed gene1 (Meg1) in maize is both necessary and sufficient for the establishment and differentiation of the endosperm nutrient transfer cells located at the mother:seed interface. Consistent with these findings, Meg1 also regulates maternal nutrient uptake, sucrose partitioning, and seed biomass yield. In addition, we generated an imprinted and nonimprinted synthetic Meg1 ((syn)Meg1) dosage series whereby increased dosage and absence of imprinting both resulted in an unequal investment of maternal resources into the endosperm. These findings highlight dosage regulation by genomic imprinting as being critical for maintaining a balanced distribution of maternal nutrients to filial tissues in plants, as in mammals. However, unlike in mammals, Meg1 is a maternally expressed imprinted gene that surprisingly acts to promote rather than restrict nutrient allocation to the offspring.

  3. Interaction between ungulates and bruchid beetles and its effect on Acacia trees: modeling the costs and benefits of seed dispersal to plant demography.

    Science.gov (United States)

    Rodríguez-Pérez, Javier; Wiegand, Kerstin; Ward, David

    2011-09-01

    Integrative studies of plant-animal interactions that incorporate the multiple effects of interactions are important for discerning the importance of each factor within the population dynamics of a plant species. The low regeneration capacity of many Acacia species in arid savannas is a consequence of a combination of reduction in seed dispersal and high seed predation. Here we studied how ungulates (acting as both seed dispersers and herbivores) and bruchid beetles (post-dispersal seed predators) modulate the population dynamics of A. raddiana, a keystone species in the Middle East. We developed two simulation models of plant demography: the first included seed ingestion by ungulates and seed predation by bruchids, whereas the second model additionally incorporated herbivory by ungulates. We also included the interacting effects of seed removal and body mass, because larger ungulates destroy proportionally fewer seeds and enhance seed germination. Simulations showed that the negative effect of seed predation on acacia population size was compensated for by the positive effect of seed ingestion at 50 and 30% seed removal under scenarios with and without herbivory, respectively. Smaller ungulates (e.g., seeds than larger ungulates (e.g., >250 kg) to compensate for the negative effect of seed predation. Seedling proportion increased with seed removal in the model with herbivory. Managing and restoring acacia seed dispersers is key to conserving acacia populations, because low-to-medium seed removal could quickly restore their regeneration capacity.

  4. The effects of seeding sterile triticale on a native plant community after wildfire in a pinyon pinemountain mahogany woodland

    Science.gov (United States)

    Waitman, B.A.; Draper, T.M.; Esque, T.C.

    2009-01-01

    Post-fire seeding with grasses is a common practice for emergency rehabilitation of burned woodlands. However, most post-seeding monitoring does not address consequences to native flora. In November 2004, the US Forest Service hand-seeded triticale (Triticosecale Wittm. ex A. Camus), a sterile wheatrye hybrid, on a small burned area in the Spring Mountains of southern Nevada, United States. A monitoring project using paired plots was designed to quantify the effects of seeding triticale on density and species richness of native annual and perennial plants, cover of perennial plants, and aboveground production of annual plants. We did not find any effects of triticale seeding on annual plant species or most responses of perennial plants. However, the density of woody perennial seedlings was significantly lower 2 years after triticale was added. Although we found a smaller impact from seeding with exotic grass than other studies, quantifiable costs to native vegetation were observed. We caution against the use of non-native grass for seeding in areas with naturally low perennial recruitment. ?? IAWF 2009.

  5. A technique for estimating seed production of common moist-soil plants - Fish and Wildlife Leaflet 13.4.5

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Contains methods to estimate seed production of moist-soil plants inlcuding survey design - Leaflet is part of the Wetland Management Book series.

  6. Using hyperspectral imaging to determine germination of native Australian plant seeds.

    Science.gov (United States)

    Nansen, Christian; Zhao, Genpin; Dakin, Nicole; Zhao, Chunhui; Turner, Shane R

    2015-04-01

    We investigated the ability to accurately and non-destructively determine the germination of three native Australian tree species, Acacia cowleana Tate (Fabaceae), Banksia prionotes L.F. (Proteaceae), and Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson (Myrtaceae) based on hyperspectral imaging data. While similar studies have been conducted on agricultural and horticultural seeds, we are unaware of any published studies involving reflectance-based assessments of the germination of tree seeds. Hyperspectral imaging data (110 narrow spectral bands from 423.6nm to 878.9nm) were acquired of individual seeds after 0, 1, 2, 5, 10, 20, 30, and 50days of standardized rapid ageing. At each time point, seeds were subjected to hyperspectral imaging to obtain reflectance profiles from individual seeds. A standard germination test was performed, and we predicted that loss of germination was associated with a significant change in seed coat reflectance profiles. Forward linear discriminant analysis (LDA) was used to select the 10 spectral bands with the highest contribution to classifications of the three species. In all species, germination decreased from over 90% to below 20% in about 10-30days of experimental ageing. P50 values (equal to 50% germination) for each species were 19.3 (A. cowleana), 7.0 (B. prionotes) and 22.9 (C. calophylla) days. Based on independent validation of classifications of hyperspectral imaging data, we found that germination of Acacia and Corymbia seeds could be classified with over 85% accuracy, while it was about 80% for Banksia seeds. The selected spectral bands in each LDA-based classification were located near known pigment peaks involved in photosynthesis and/or near spectral bands used in published indices to predict chlorophyll or nitrogen content in leaves. The results suggested that seed germination may be successfully classified (predicted) based on reflectance in narrow spectral bands associated with the primary metabolism

  7. An Effective System to Produce Smoke Solutions from Dried Plant Tissue for Seed Germination Studies

    OpenAIRE

    Janice Coons; Nancy Coutant; Barbara Lawrence; Daniel Finn; Stephanie Finn

    2014-01-01

    • Premise of the study: An efficient and inexpensive system was developed to produce smoke solutions from plant material to research the influence of water-soluble compounds from smoke on seed germination. • Methods and Results: Smoke solutions (300 mL per batch) were produced by burning small quantities (100–200 g) of dried plant material from a range of species in a bee smoker attached by a heater hose to a side-arm flask. The flask was attached to a vacuum water aspirator, to pull the smok...

  8. Demarcation of mutant-carrying regions in barley plants after ethylmethane-sulfonate seed treatment

    DEFF Research Database (Denmark)

    Jacobsen, P.

    1966-01-01

    was obtained.The absence of cluster sharing allows the recognition in the barley plant of 8 mutually exclusive mutant sectors which never had a mutant cluster in common. The anatomical analysis proves that the barley embryo contains at least 6 separate shoot meristems or prospective shoot meristems, which...... will constitute mutually exclusive mutant sectors in the plant. The combined genetical and anatomical analysis reveals that in large seeds there are always 9 meristems leading to 9 mutually exclusive mutant sectors. Up to 7 additional meristems leading to mutually exclusive mutant sectors can be present...

  9. CURE-Chloroplast: A chloroplast C-to-U RNA editing predictor for seed plants

    OpenAIRE

    2009-01-01

    Abstract Background RNA editing is a type of post-transcriptional modification of RNA and belongs to the class of mechanisms that contribute to the complexity of transcriptomes. C-to-U RNA editing is commonly observed in plant mitochondria and chloroplasts. The in vivo mechanism of recognizing C-to-U RNA editing sites is still unknown. In recent years, many efforts have been made to computationally predict C-to-U RNA editing sites in the mitochondria of seed plants, but there is still no algo...

  10. Survival and DNA Damage in Plant Seeds Exposed for 558 and 682 Days outside the International Space Station.

    Science.gov (United States)

    Tepfer, David; Leach, Sydney

    2017-03-01

    For life to survive outside the biosphere, it must be protected from UV light and other radiation by exterior shielding or through sufficient inherent resistance to survive without protection. We tested the plausibility of inherent resistance in plant seeds, reporting in a previous paper that Arabidopsis thaliana and tobacco (Nicotiana tabacum) seeds exposed for 558 days outside the International Space Station (ISS) germinated and developed into fertile plants after return to Earth. We have now measured structural genetic damage in tobacco seeds from this EXPOSE-E experiment by quantitatively amplifying a segment of an antibiotic resistance gene, nptII, inserted into the chloroplast genome. We also assessed the survival of the antibiotic resistance encoded by nptII, using marker rescue in a soil bacterium. Chloroplast DNA damage occurred, but morphological mutants were not detected among the survivors. In a second, longer mission (EXPOSE-R), a nearly lethal exposure was received by Arabidopsis seeds. Comparison between a ground simulation, lacking UVspace indicated severe damage from these short wavelengths and again suggested that DNA degradation was not limiting seed survival. To test UV resistance in long-lived, larger seeds, we exposed Arabidopsis, tobacco, and morning glory seeds in the laboratory to doses of UV254nm, ranging as high as 2420 MJ m(-2). Morning glory seeds resisted this maximum dose, which killed tobacco and Arabidopsis. We thus confirm that a naked plant seed could survive UV exposures during direct transfer from Mars to Earth and suggest that seeds with a more protective seed coat (e.g., morning glory) should survive much longer space travel. Key Words: UV light-Flavonoids-Sinapate-DNA degradation-Arabidopsis-Tobacco-Seeds-Space-International Space Station-EXPOSE-E-EXPOSE-R. Astrobiology 17, 205-215.

  11. Development of marker-free transgenic Jatropha plants with increased levels of seed oleic acid

    Directory of Open Access Journals (Sweden)

    Qu Jing

    2012-02-01

    Full Text Available Abstract Background Jatropha curcas is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission. Results The enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2 is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative delta 12 fatty acid desaturase genes in Jatropha (JcFAD2s through genome-wide analysis and downregulated the expression of one of these genes, JcFAD2-1, in a seed-specific manner by RNA interference technology. The resulting JcFAD2-1 RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78% and a corresponding reduction in polyunsaturated fatty acids (Jatropha had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in Jatropha. Due to the changes in the fatty acids profile, the oil of the JcFAD2-1 RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60 in Europe. The presence of high seed oleic acid did not have a negative impact on other Jatropha agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic Jatropha

  12. Implications of lemuriform extinctions for the Malagasy flora.

    Science.gov (United States)

    Federman, Sarah; Dornburg, Alex; Daly, Douglas C; Downie, Alexander; Perry, George H; Yoder, Anne D; Sargis, Eric J; Richard, Alison F; Donoghue, Michael J; Baden, Andrea L

    2016-05-01

    Madagascar's lemurs display a diverse array of feeding strategies with complex relationships to seed dispersal mechanisms in Malagasy plants. Although these relationships have been explored previously on a case-by-case basis, we present here the first comprehensive analysis of lemuriform feeding, to our knowledge, and its hypothesized effects on seed dispersal and the long-term survival of Malagasy plant lineages. We used a molecular phylogenetic framework to examine the mode and tempo of diet evolution, and to quantify the associated morphological space occupied by Madagascar's lemurs, both extinct and extant. Using statistical models and morphometric analyses, we demonstrate that the extinction of large-bodied lemurs resulted in a significant reduction in functional morphological space associated with seed dispersal ability. These reductions carry potentially far-reaching consequences for Malagasy ecosystems, and we highlight large-seeded Malagasy plants that appear to be without extant animal dispersers. We also identify living lemurs that are endangered yet occupy unique and essential dispersal niches defined by our morphometric analyses.

  13. Loss of animal seed dispersal increases extinction risk in a tropical tree species due to pervasive negative density dependence across life stages

    NARCIS (Netherlands)

    Caughlin, T.T.; Ferguson, J.M.; Lichstein, J.W.; Zuidema, P.A.; Bunyavejchewin, S.; Levey, D.J.

    2015-01-01

    Overhunting in tropical forests reduces populations of vertebrate seed dispersers. If reduced seed dispersal has a negative impact on tree population viability, overhunting could lead to altered forest structure and dynamics, including decreased biodiversity. However, empirical data showing

  14. Loss of animal seed dispersal increases extinction risk in a tropical tree species due to pervasive negative density dependence across life stages

    NARCIS (Netherlands)

    Caughlin, T.T.; Ferguson, J.M.; Lichstein, J.W.; Zuidema, P.A.; Bunyavejchewin, S.; Levey, D.J.

    2015-01-01

    Overhunting in tropical forests reduces populations of vertebrate seed dispersers. If reduced seed dispersal has a negative impact on tree population viability, overhunting could lead to altered forest structure and dynamics, including decreased biodiversity. However, empirical data showing decrease

  15. Heterologous expression of chloroplast-localized geranylgeranyl pyrophosphate synthase confers fast plant growth, early flowering and increased seed yield.

    Science.gov (United States)

    Tata, Sandeep Kumar; Jung, Jihye; Kim, Yoon-Ha; Choi, Jun Young; Jung, Ji-Yul; Lee, In-Jung; Shin, Jeong Sheop; Ryu, Stephen Beungtae

    2016-01-01

    Geranylgeranyl pyrophosphate synthase (GGPS) is a key enzyme for a structurally diverse class of isoprenoid biosynthetic metabolites including gibberellins, carotenoids, chlorophylls and rubber. We expressed a chloroplast-targeted GGPS isolated from sunflower (Helianthus annuus) under control of the cauliflower mosaic virus 35S promoter in tobacco (Nicotiana tabacum). The resulting transgenic tobacco plants expressing heterologous GGPS showed remarkably enhanced growth (an increase in shoot and root biomass and height), early flowering, increased number of seed pods and greater seed yield compared with that of GUS-transgenic lines (control) or wild-type plants. The gibberellin levels in HaGGPS-transgenic plants were higher than those in control plants, indicating that the observed phenotype may result from increased gibberellin content. However, in HaGGPS-transformant tobacco plants, we did not observe the phenotypic defects such as reduced chlorophyll content and greater petiole and stalk length, which were previously reported for transgenic plants expressing gibberellin biosynthetic genes. Fast plant growth was also observed in HaGGPS-expressing Arabidopsis and dandelion plants. The results of this study suggest that GGPS expression in crop plants may yield desirable agronomic traits, including enhanced growth of shoots and roots, early flowering, greater numbers of seed pods and/or higher seed yield. This research has potential applications for fast production of plant biomass that provides commercially valuable biomaterials or bioenergy. © 2015 Korea Research Institute of Bioscience & Biotechnology. Plant Biotechnology Journal published by John Wiley & Sons Ltd and Society for Experimental Biology, Association of Applied Biologists.

  16. ln vitro propagation of Hylocereus purpusii Britton & Rose, a mexican species in danger of extinction

    OpenAIRE

    Manuel de Feria; Daniel Rojas; Maité Chávez; Mireya Reyna; Elisa Quiala; Juan Solís; Florentina Zurita

    2012-01-01

    The purpose ofthis workwasto evalúate different conditions and culture parametersforthein vitro establishment and multiplicaron of Hylocereus purpusii. Seeds were used as plant material and a workflowwas developed as an alternative forthe propagation and recovery ofthis species in danger of extinction. ln the establishment phase, the best result was obtained in the treatment with 1% NaOCI for 15 minutes achieving a 90% of germinated seeds and a final 77.7% of in vitro established plants. ln t...

  17. Seed Treatment with Auxins Modulates Growth and Ion Partitioning in Salt-stressed Wheat Plants

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Experiments were performed to determine whether seed priming with different concentrations (100, 150, and 200 mg/L) of auxins (indoleacetic acid (IAA), indolebutyric acid (IBA), or their precursor tryptophane (Trp)) could alter salinity induced perturbances in salicylic acid and ion concentrations and, hence, growth in wheat (Triticum aestivum L.) cultivars, namely M.H.-97 (salt intolerant) and Inqlab-91 (salt tolerant). Primed and non-primed seeds were sown in Petri dishes in a growth room, as well as in a field treated with 15 dS/m NaCl salinity. All priming agents, except IBA, increased the final germination percentage in both cultivars. The seedlings of either cultivar raised from Trp-treated seeds had greater dry biomass when under salt stress. In field experiments, Trp priming was much more effective in mediating the increase in grain yield,irrespective of the cultivar, under salt stress. The alleviatory effect of Trp was found to be associated with reduced uptake of Na+ in the roots and subsequent translocation to the shoots, as well as increased partitioning of Ca2+ in the roots of salt-stressed wheat plants. Plants of both cultivars raised from Trp- and IAA-treated seeds accumulated free salicylic acid in their leaves when under salt stress. Overall, the Trp priming-induced improvement in germination and the subsequent growth of wheat plants could be related to ion homeostasis when under salt stress. The possible involvement of salicylic acid in the Trp priming-induced better growth under conditions of salt stress is discussed.

  18. [Analysis of quantitative traits connected with seed weight and flowering terms in birdsfoot trefoil (Lotus corniculatus L.) plants].

    Science.gov (United States)

    Nikolaĭchuk, V I

    2000-01-01

    The nature of inheritance of characters connected with the seed size (seed mass) and quality of the shoots (germination energy, seed viability, general shoot length, shoot mass, dry weight of shoots) in Lotus corniculatus L. was analyzed. The investigations were carried out on plants of three varieties: the wild form from the Krasnodar Region and local forms MF1 and MF3. The correlation analysis was carried out. The pattern of inheritance in the terms of plant flowering and length of shoots were studied.

  19. Comparison of tree growth and undergrowth development in aerially seeded and planted Pinus tabulaeformis forests

    Institute of Scientific and Technical Information of China (English)

    Guolei LI; Yong LIU; Lvyi MA; Ruiheng LV; Haiqun YU; Shulan Bai; Yaoyao KANG

    2009-01-01

    Direct seeding is a less expensive practice than planting and has the potential to become a viable alternative to transplanting for afforestation and regeneration purposes. As an effective and a less costly regeneration method, aerial seeding has been applied with several tree species. As early as 1956, Chinese people engaged in aerial seeding and stands with a total of 2.97×107hm2 have been developed up to 2004. Our study tested whether the growth of planted Chinese pine (Pinus tabulaeformis Carr.) seedlings and its undergrowth development in northwest aspects differ from that of aerially sown seedlings on the northern and northwestern aspects of slopes. In 2007, we collected data such as height, diameter at breast height (DBH), clear bole height and canopy widths of trees, abundance, coverage, and frequency of shrubs and herbs from 21-year-old planted Chinese pine stands on a northwestern aspect (PNW), aerially sown stands in a northwest aspect (ANW) and aerially sown stands in a northern aspect (AN). Results showed that the relation of crown area and mean DBH was best fitted by a double inverse model for the ANW and AN forests and by a quadratic model for the PNW forest. There was no difference in the growth between ANW and AN forests, while growth was significantly higher in the PNW forest than in the ANW and AN forests. That was consistent with the Sorenson diversity indices in the shrub and herb layers, indicating that there was a large number of the same species in both aerially seeded stands, although their locations were different. Both the number of species in the undergrowth and the Shannon-Wiener index in the shrub layer were higher in the PNW stands than in the ANW and AN stands. Dominant families for all three stands were Rosaceae and Compositae in the shrub and herb layer, respectively. The dominant species for all three stands was Spiraea pubescens in the shrub layer, while the dominant species was different from each other in the three stands. The

  20. Mechanistic models of plant seed dispersal by wind in heterogeneous landscapes

    Science.gov (United States)

    Trakhtenbrot, A.; Katul, G. G.; Nathan, R.

    2010-12-01

    Seed dispersal, and especially long-distance dispersal (LDD), is a key process in plant population survival, colonization, and gene flow. Its importance is amplified by the man-induced habitat fragmentation, climate change and invasions of exotic species. Mechanistic seed dispersal models are central to quantitative prediction of dispersal patterns and understanding their underlying mechanisms. For wind dispersal, most current mechanistic models assume homogenous environment. Although both topography and sharp transitions in vegetation stature profoundly affect wind flow, accounting for these effects via simplified models remains a vexing research problem. Such simplified models are needed to inform ecosystem managers about consequences of landscape fragmentation. We modified the Coupled Eulerian-Lagrangian closure (CELC) mechanistic dispersal model to represent scenarios of wind flow over a sharp transition from short to tall vegetation or over forested hilly terrain, and predicted the resulting dispersal distances and direction. We parameterized the wind and vegetation factors using measurements taken on a hill with short height Mediterranean shrubland and pine forest vegetation at Mt. Pithulim, Israel. For the short-to-tall vegetation transition scenario, the main feature of the modeled wind field is an exponential decay of the mean horizontal wind velocity, assuming that the mean momentum equation simplifies to a balance between the advective acceleration and the drag force terms. As a consequence of the incompressibility condition, this exponential decay leads to strong upward mean vertical velocity component. We found that for seed release downwind of the edge, the simulated median (short) and 99-th percentile (long) distances were longer than those for the homogeneous tall vegetation scenario. For seed release upwind of the edge the effect on dispersal distance was more complex and depended on the release height and he seed terminal velocity of the seeds

  1. Rethinking Extinction.

    Science.gov (United States)

    Dunsmoor, Joseph E; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A

    2015-10-07

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavioral technique, and consider whether traditional understandings warrant a re-examination. We discuss the neurobiology, cognitive factors, and major computational theories, and revisit the predominant view that extinction results in new learning that interferes with expression of the original memory. Additionally, we reconsider the limitations of extinction as a technique to prevent the relapse of maladaptive behavior and discuss novel approaches, informed by contemporary theoretical advances, that augment traditional extinction methods to target and potentially alter maladaptive memories. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Rethinking Extinction

    OpenAIRE

    Dunsmoor, Joseph E.; Niv, Yael; Daw, Nathaniel; Phelps, Elizabeth A.

    2015-01-01

    Extinction serves as the leading theoretical framework and experimental model to describe how learned behaviors diminish through absence of anticipated reinforcement. In the past decade, extinction has moved beyond the realm of associative learning theory and behavioral experimentation in animals and has become a topic of considerable interest in the neuroscience of learning, memory, and emotion. Here, we review research and theories of extinction, both as a learning process and as a behavior...

  3. Effects of moist cold stratification on germination, plant growth regulators, metabolites and embryo ultrastructure in seeds of Acer morrisonense (Sapindaceae).

    Science.gov (United States)

    Chen, Shun-Ying; Chou, Shih-Han; Tsai, Ching-Chu; Hsu, Wen-Yu; Baskin, Carol C; Baskin, Jerry M; Chien, Ching-Te; Kuo-Huang, Ling-Long

    2015-09-01

    Breaking of seed dormancy by moist cold stratification involves complex interactions in cells. To assess the effect of moist cold stratification on dormancy break in seeds of Acer morrisonense, we monitored percentages and rates of germination and changes in plant growth regulators, sugars, amino acids and embryo ultrastructure after various periods of cold stratification. Fresh seeds incubated at 25/15 °C for 24 weeks germinated to 61%, while those cold stratified at 5 °C for 12 weeks germinated to 87% in 1 week. Neither exogenous GA3 nor GA4 pretreatment significantly increased final seed germination percentage. Total ABA content of seeds cold stratified for 12 weeks was reduced about 3.3-fold, to a concentration similar to that in germinated seeds (radicle emergence). Endogenous GA3 and GA7 were detected in 8-week and 12-week cold stratified seeds but not in fresh seeds. Numerous protein and lipid bodies were present in the plumule, first true leaves and cotyledons of fresh seeds. Protein and lipid bodies decreased greatly during cold stratification, and concentrations of total soluble sugars and amino acids increased. The major non-polar sugars in fresh seeds were sucrose and fructose, but sucrose increased and fructose decreased significantly during cold stratification. The major free amino acids were proline and tryptophan in fresh seeds, and proline increased and tryptophan decreased during cold stratification. Thus, as dormancy break occurs during cold stratification seeds of A. morrisonense undergo changes in plant growth regulators, proteins, lipids, sugars, amino acids and cell ultrastructure.

  4. Importance of seed-borne fungi of sorghum and pearl millet in Burkina Faso and their control using plant extracts.

    Science.gov (United States)

    Zida, Pawindé Elisabeth; Sérémé, Paco; Leth, Vibeke; Sankara, Philippe; Somda, Irénée; Néya, Adama

    2008-02-01

    Seed-borne fungi of sorghum and pearl millet in Burkina Faso were surveyed. A total of 188 seed samples from various locations, collected in 1989 (42) and 2002 (146), were tested, using the blotter, dry inspection and washing methods. Infection experiments were carried out with the major fungi recorded on each crop by the blotter test. Six essential oils of plants were investigated for their inhibitory activity against eight pathogenic fungi. Thirty four and 27 fungal species were found in seed samples of sorghum and pearl millet, respectively. Phoma sp. and Fusarium moniliforme infected 95 to 100% of the seed samples of both sorghum and pearl millet. Sphacelotheca sorghi and Tolyposporium ehrenbergii were encountered in respectively, 75 and 33% of seed samples of sorghum. T. penicillariae, Sclerospora graminicola and Claviceps fusiformis were present in 88, 41 and 32% of seed samples of pearl millet, respectively. Seeds inoculated with Acremonium strictum, Curvularia oryzae, F. equiseti, F. moniliforme and F. subglutinans and sown in sterilized soil, showed considerable mortality of the seedlings. Three essential oils inhibited in vitro the mycelial growth of all the fungi used by 85 to 100% and reduced significantly sorghum and pearl millet seed infection rates of Phoma sp., Fusarium sp., Curvularia sp., Colletotrichum graminicola and Exserohilum sp. Presence of many pathogenic fungi in considerable number of seed samples indicates the need of field surveys for these and other pathogens. Development of plant extracts for the control of seed-borne pathogens and public awareness on seed-borne diseases management measures for maintaining quality seed should be increased.

  5. Spatial niche facilitates clonal reproduction in seed plants under temporal disturbance.

    Directory of Open Access Journals (Sweden)

    Shin Fukui

    Full Text Available The evolutionary origins and advantages of clonal reproduction relative to sexual reproduction have been discussed for several taxonomic groups. In particular, organisms with a sessile lifestyle are often exposed to spatial and temporal environmental fluctuations. Thus, clonal propagation may be advantageous in such fluctuating environments, for sessile species that can reproduce both sexually and clonally. Here we introduce the concept of niche to a lattice space that changes spatially and temporally, by incorporating the compatibility between the characteristics of a sessile clonal plant with its habitat into a spatially explicit individual-based model. We evaluate the impact of spatially and temporally heterogeneous environments on the evolution of reproductive strategies: the optimal balance between seed and clonal reproduction of a clonal plant. The spatial niche case with local habitats led to avoidance of specialization in reproductive strategy, whereas stable environments or intensive environmental change tended to result in specialization in either clonal or seed reproduction under neutral conditions. Furthermore, an increase in spatial niches made clonal reproduction advantageous, as a consequence of competition among several genets under disturbed conditions, because a ramet reached a favorable habitat through a rare long-distance dispersal event via seed production. Thus, the existence of spatial niches could explain the advantages of clonal propagation.

  6. Spatial niche facilitates clonal reproduction in seed plants under temporal disturbance.

    Science.gov (United States)

    Fukui, Shin; Araki, Kiwako S

    2014-01-01

    The evolutionary origins and advantages of clonal reproduction relative to sexual reproduction have been discussed for several taxonomic groups. In particular, organisms with a sessile lifestyle are often exposed to spatial and temporal environmental fluctuations. Thus, clonal propagation may be advantageous in such fluctuating environments, for sessile species that can reproduce both sexually and clonally. Here we introduce the concept of niche to a lattice space that changes spatially and temporally, by incorporating the compatibility between the characteristics of a sessile clonal plant with its habitat into a spatially explicit individual-based model. We evaluate the impact of spatially and temporally heterogeneous environments on the evolution of reproductive strategies: the optimal balance between seed and clonal reproduction of a clonal plant. The spatial niche case with local habitats led to avoidance of specialization in reproductive strategy, whereas stable environments or intensive environmental change tended to result in specialization in either clonal or seed reproduction under neutral conditions. Furthermore, an increase in spatial niches made clonal reproduction advantageous, as a consequence of competition among several genets under disturbed conditions, because a ramet reached a favorable habitat through a rare long-distance dispersal event via seed production. Thus, the existence of spatial niches could explain the advantages of clonal propagation.

  7. The signatures of Anthropocene defaunation: cascading effects of the seed dispersal collapse.

    Science.gov (United States)

    Pérez-Méndez, Néstor; Jordano, Pedro; García, Cristina; Valido, Alfredo

    2016-04-19

    Anthropogenic activity is driving population declines and extinctions of large-bodied, fruit-eating animals worldwide. Loss of these frugivores is expected to trigger negative cascading effects on plant populations if remnant species fail to replace the seed dispersal services provided by the extinct frugivores. A collapse of seed dispersal may not only affect plant demography (i.e., lack of recruitment), but should also supress gene flow via seed dispersal. Yet little empirical data still exist demonstrating the genetic consequences of defaunation for animal-dispersed plant species. Here, we first document a significant reduction of seed dispersal distances along a gradient of human-driven defaunation, with increasing loss of large- and medium-bodied frugivores. We then show that local plant neighbourhoods have higher genetic similarity, and smaller effective population sizes when large seed dispersers become extinct (i.e., only small frugivores remain) or are even partially downgraded (i.e., medium-sized frugivores providing less efficient seed dispersal). Our results demonstrate that preservation of large frugivores is crucial to maintain functional seed dispersal services and their associated genetic imprints, a central conservation target. Early signals of reduced dispersal distances that accompany the Anthropogenic defaunation forecast multiple, cascading effects on plant populations.

  8. The K+-dependent asparaginase, NSE1, is crucial for plant growth and seed production in Lotus japonicus.

    Science.gov (United States)

    Credali, Alfredo; García-Calderón, Margarita; Dam, Svend; Perry, Jillian; Díaz-Quintana, Antonio; Parniske, Martin; Wang, Trevor L; Stougaard, Jens; Vega, José M; Márquez, Antonio J

    2013-01-01

    The physiological role of K(+)-dependent and K(+)-independent asparaginases in plants remains unclear, and the contribution from individual isoforms during development is poorly understood. We have used reverse genetics to assess the phenotypes produced by the deficiency of K(+)-dependent NSE1 asparaginase in the model legume Lotus japonicus. For this purpose, four different mutants were identified by TILLING and characterized, two of which affected the structure and function of the asparaginase molecule and caused asparagine accumulation. Plant growth and total seed weight of mature mutant seeds as well as the level of both legumin and convicilin seed storage proteins were affected in the mutants. The mutants isolated in the present work are the first of their type in legumes and have enabled us to demonstrate the importance of asparagine and K(+)-dependent NSE1 asparaginase for nitrogen remobilization and seed production in L. japonicus plants.

  9. SEED GERMINATION AND PLANT DEVELOPMENT IN Escobedia grandiflora (OROBANCHACEAE: EVIDENCE OF OBLIGATE HEMIPARASITISM?

    Directory of Open Access Journals (Sweden)

    Edison CARDONA-MEDINA

    2015-07-01

    Full Text Available Root parasitic plants can be facultative or obligate. Facultative parasites are able to complete their life cycle and their seeds can germinate without a host. Escobedia grandiflora is a poorly studied species in spite of its ancestral importance as dye of foods and medicinal use. The present study evaluates the states of seed, seedlings and mature plants, under presence and absence of possible hosts, for inferring the type of parasitism exhibited by E. grandiflora. Seeds were evaluated using two conditions each of light (12 and 0 hours and temperature (20 ºC and 25 ºC; percentage germination, and germination speed were determined. The seeds did not require a host to germinate, as is typical of facultative parasitic plants.  Percentage of germination varied between 66 % and 85.3 % and was not affected by light or temperature although germination speed was greater at 25 ºC. Larger seeds had a higher percentage of germination and produced larger seedlings. The seedlings planted without a host did not survive, while those planted with Paspalum notatum had a 45 % survival rate, demonstrating that this is a critical stage of development, even with a host. Escobedia grandiflora plants sowed with grasses began the reproductive stage at the 28th week, and those planted with Pennisetum purpureum showed better performance, expressed in more haustoria, higher dry matter of total plant, rhizome and aerial stems. Plants sowed alone lived for more than six months, but they did not produce flowers or fruits. According to the behavior of seedlings and plants, E. grandiflora is an obligate parasite. Germinación de semillas y desarrollo de plantas en Escobedia grandiflora (Orobanchaceae: ¿Evidencia de hemiparasitismo obligado? Las plantas parásitas de raíces pueden ser facultativas u obligadas, las primeras pueden completar su ciclo de vida y sus semillas pueden germinar sin un hospedero. Escobedia grandiflora es una especie poco estudiada, a pesar de

  10. Interactions between a pollinating seed predator and its host plant: the role of environmental context within a population.

    Science.gov (United States)

    Kula, Abigail A R; Castillo, Dean M; Dudash, Michele R; Fenster, Charles B

    2014-07-01

    Plant-insect interactions often are important for plant reproduction, but the outcome of these interactions may vary with environmental context. Pollinating seed predators have positive and negative effects on host plant reproduction, and the interaction outcome is predicted to vary with density or abundance of the partners. We studied the interaction between Silene stellata, an herbaceous perennial, and Hadena ectypa, its specialized pollinating seed predator. Silene stellata is only facultatively dependent upon H. ectypa for pollination because other nocturnal moth co-pollinators are equally effective at pollen transfer. We hypothesized that for plants without conspecific neighbors, H. ectypa would have higher visitation rates compared to co-pollinators, and the plants would experience lower levels of H. ectypa pollen deposition. We predicted similar oviposition throughout the study site but greater H. ectypa predation in the area without conspecific neighbors compared to plants embedded in a naturally high density area. We found that H. ectypa had consistently higher visitation than moth co-pollinators in all host plant contexts. However, H. ectypa pollinator importance declined in areas with low conspecific density because of reduced pollen deposition, resulting in lower seed set. Conversely, oviposition was similar across the study site independent of host plant density. Greater likelihood of very high fruit predation combined with lower pollination by H. ectypa resulted in reduced S. stellata female reproductive success in areas with low conspecific density. Our results demonstrate local context dependency of the outcomes of pollinating seed predator interactions with conspecific host plant density within a population.

  11. Synthetic seed production and physio-biochemical studies in Cassia angustifolia Vahl. - a medicinal plant.

    Science.gov (United States)

    Bukhari, N A W; Siddique, Iram; Perveen, K; Siddiqui, I; Alwahibi, M S

    2014-09-01

    Synthetic seed technology is an alternative to traditional micropropagation for production and delivery of cloned plantlets. Synthetic seeds were produced by encapsulating nodal segments of C. angustifolia in calcium alginate gel. 3% (w/v) sodium alginate and 100 mM CaCl2 · 2H2O were found most suitable for encapsulation of nodal segments. Synthetic seeds cultured on half strength Murashige and Skoog medium supplemented with thidiazuron (5.0 μM) + indole-3-acetic acid (1.0 μM) produced maximum number of shoots (10.9 ± 0.78) after 8 weeks of culture exhibiting (78%) in vitro conversion response. Encapsulated nodal segments demonstrated successful regeneration after different period (1-6 weeks) of cold storage at 4 °C. The synthetic seeds stored at 4 °C for a period of 4 weeks resulted in maximum conversion frequency (93%) after 8 weeks when placed back to regeneration medium. The isolated shoots when cultured on half strength Murashige and Skoog medium supplemented with 1.0 μM indole-3-butyric acid (IBA), produced healthy roots and plantlets with well-developed shoot and roots were successfully hardened off in plastic pots containing sterile soilrite inside the growth chamber and gradually transferred to greenhouse where they grew well with 85% survival rate. Growth performance of 2 months old in vitro-raised plant was compared with in vivo seedlings of the same age. Changes in the content of photosynthetic pigments, net photosynthetic rate (PN), superoxide dismutase and catalase activity in C. angustifolia indicated the adaptation of micropropagated plants to ex vitro conditions.

  12. Plant seed species identification from chemical fingerprints: a high-throughput application of direct analysis in real time mass spectrometry.

    Science.gov (United States)

    Lesiak, Ashton D; Cody, Robert B; Dane, A John; Musah, Rabi A

    2015-09-01

    Plant species identification based on the morphological features of plant parts is a well-established science in botany. However, species identification from seeds has largely been unexplored, despite the fact that the seeds contain all of the genetic information that distinguishes one plant from another. Using seeds of genus Datura plants, we show here that the mass spectrum-derived chemical fingerprints for seeds of the same species are similar. On the other hand, seeds from different species within the same genus display distinct chemical signatures, even though they may contain similar characteristic biomarkers. The intraspecies chemical signature similarities on the one hand, and interspecies fingerprint differences on the other, can be processed by multivariate statistical analysis methods to enable rapid species-level identification and differentiation. The chemical fingerprints can be acquired rapidly and in a high-throughput manner by direct analysis in real time mass spectrometry (DART-MS) analysis of the seeds in their native form, without use of a solvent extract. Importantly, knowledge of the identity of the detected molecules is not required for species level identification. However, confirmation of the presence within the seeds of various characteristic tropane and other alkaloids, including atropine, scopolamine, scopoline, tropine, tropinone, and tyramine, was accomplished by comparison of the in-source collision-induced dissociation (CID) fragmentation patterns of authentic standards, to the fragmentation patterns observed in the seeds when analyzed under similar in-source CID conditions. The advantages, applications, and implications of the chemometric processing of DART-MS derived seed chemical signatures for species level identification and differentiation are discussed.

  13. Agro-economic performance of Comum tannia cultivated with plant spacing and different seed-rhizome masse

    Directory of Open Access Journals (Sweden)

    Rosimeire Pereira Gassi

    2014-02-01

    Full Text Available The study aimed to evaluate the increase in plant height and agro-economic productivity of Comum tannia cultivated using two different row spacing (0.10 and 0.15 m and four seed-rhizome masses (5.52 g; 3.76 g, 2.17 g, and 1.44 g, mean of 480 rhizomes. The plants were cultivated in a 2 × 4-factorial scheme, completely randomized block design, with three replications. The maximum height of the plants reached 43.2 cm at 179 days after planting with a seed-rhizome mass of 5.52 g and 0.15-m space between plants. The highest fresh mass yields of the aerial parts (1.74 t·ha-1 of medium (3.25 t·ha-1 and small (4.24 t·ha-1 cormels were obtained in plants propagated using a seed-rhizome mass of 3.76 g. The highest yields of corm (2.64 t·ha-1 and large cormels (2.37 t·ha-1 were achieved using a seed-rhizome mass of 5.52 g. The diameters and lengths of corms and cormels showed a direct relationship with the seedling mass, except for the diameters of small cormels, which were higher in plants propagated using a seed-rhizome mass of 1.44 g. Thus, it was concluded that to achieve increased plant height, production of commercial rhizomes, and gross and net incomes, Comum tannia should be propagated using seed-rhizome mass of 5.52 g and plant spacing of 0.15 m.

  14. A COMPARATIVE STUDY OF PLANT GROWTH REGULATORS ON MORPHOLOGICAL, SEED YIELD AND QUALITY PARAMETERS OF GREENGRAM

    Directory of Open Access Journals (Sweden)

    K Rajesh

    2014-09-01

    Full Text Available A field experiment was conducted to study the different growth regulating compounds on morphological, quality and yield parameters in greengram at Acharya N.G Ranga Agricultural University, Hyderabad during rabi 2009- 10. The basic material for the present investigation consists of Greengram cv WGG-37 and two growth promoting (NAA and Brassinosteroid and growth retarding substances (Chlormequat chloride and Mepiquat chloride. These growth regulators were sprayed at flower initiation stage. The morphological traits viz., plant height, number of branches per plant, number of trifoliates per plant and days to 50% flowering and maturity were significantly increased by NAA @ 20 ppm, whereas total dry matter production (TDM over growth regulator treatments at all stages NAA (20 ppm and brassinosteroid (20ppm recorded significantly higher values. Among the quality parameters highest seed protein content (% and highest nitrogen harvest index values were recorded with growth retarding substance chlormequat chloride (187.5 g a.i ha-1 in greengram. The seed yield increased significantly with NAA (20 ppm followed by mepiquat chloride 5% AS, brassinosteroid (20 ppm, chlormequat chloride (137.5.5 a.i/ha.

  15. Latisemenia longshania, gen. et sp. nov., a new Late Devonian seed plant from China.

    Science.gov (United States)

    Wang, De-Ming; Basinger, James F; Huang, Pu; Liu, Le; Xue, Jin-Zhuang; Meng, Mei-Cen; Zhang, Ying-Ying; Deng, Zhen-Zhen

    2015-10-22

    The earliest known ovules in the Late Devonian (Famennian) are borne terminally on fertile branches and are typically enclosed in a cupule. Among these ovules are some that have terete integumentary lobes with little or no fusion. Here, we report a new taxon, Latisemenia longshania, from the Famennian of South China, which bears cupulate ovules that are terminal as well as opposite on the fertile axis. Each ovule has four broad integumentary lobes, which are extensively fused to each other and also to the nucellus. The cupule is uniovulate, and the five flattened cupule segments of each terminal ovule are elongate cuneate and shorter than the ovule. Associated but not attached pinnules are laminate and Sphenopteris-like, with an entire or lobate margin. Latisemenia is the earliest known plant with ovules borne on the side of the fertile axis and may foreshadow the diverse ovule arrangements found among younger seed plant lineages that emerge in the Carboniferous. Following the telome theory, Latisemenia demonstrates derived features in both ovules and cupules, and the shape and fusion of integumentary lobes suggest effective pollination and protection to the nucellus. Along with other recent discoveries from China, Latisemenia extends the palaeogeographic range of the earliest seed plants. © 2015 The Author(s).

  16. Gamma radiosensitivity in tomato plants and answers from irradiated seed at different salinity levels

    Energy Technology Data Exchange (ETDEWEB)

    Colaco, Waldeciro; Bidjeke, R. [Universidade Federal de Pernambuco, Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: wcolaco@ufpe.br; Ferraz, Ednardo M. [Empresa Pernambucana de Pesquisa Agropecuaria (IPA), Recife (Brazil)

    2004-12-15

    Considering future studies of mutation induction as an auxiliary tool for the improvement of plants, preliminary experiments to evaluate the tomato plant (L. esculentum, Mill) radiosensitivity were carried out on the IPA-6, IPA-8 and L. hirsutum var. glabratum - H G varieties with a Co-60 gamma ray source, aiming to obtain varieties that are tolerant to salinity. Groups of seeds were irradiated with 300-600 Gy and with 100 to 400 Ge, were compared to a control without irradiation (0 Gy), under greenhouse conditions. The seeds were put into polystyrene boxes with 176 cells of 9 cm{sup 2} and at 5 cm in depth, containing vermiculite, soil, cow dung and washed sand (40, 20, 20, and 20% respectively). In a general way, there was stimulation in growth in the lower doses and a reduction with the increase in doses. For the IPA-6, the growth diminished with the increase in the levels of salinity, no significant interaction being observed between the levels of salinity and the doses. The ideal dosage level for tomato plant irradiation, suggested in literature (establishing themselves around 100 Gy), is not compatible with the two varieties and the wild species studies. (author)

  17. Planting Date and Seeding Rate Effects on Sunn Hemp Biomass and Nitrogen Production for a Winter Cover Crop

    Directory of Open Access Journals (Sweden)

    Kipling S. Balkcom

    2011-01-01

    Full Text Available Sunn hemp (Crotalaria juncea L. is a tropical legume that produces plant biomass and nitrogen (N quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a rye (Secale cereale L. cover crop in east-central Alabama from 2007 to 2009. Plant populations, plant height, stem diameter, biomass production, and N content were determined for two sunn hemp planting dates, following corn (Zea mays L. and wheat (Triticum aestivum L. harvest, across different seeding rates (17, 34, 50, and 67 kg/ha. Rye biomass was measured the following spring. Sunn hemp biomass production was inconsistent across planting dates, but did relate to growing degree accumulation. Nitrogen concentrations were inversely related to biomass production, and subsequent N contents corresponded to biomass levels. Neither planting date nor seeding rate affected rye biomass production, but rye biomass averaged over both planting dates following wheat/sunn hemp averaged 43% and 33% greater than rye following fallow. Rye biomass following corn/sunn hemp was equivalent to fallow plots. Early planting dates are recommended for sunn hemp with seeding rates between 17 and 34 kg/ha to maximize biomass and N production.

  18. Structure of soybean seed coat peroxidase: a plant peroxidase with unusual stability and haem-apoprotein interactions

    DEFF Research Database (Denmark)

    Henriksen, A; Mirza, O; Indiani, C

    2001-01-01

    Soybean seed coat peroxidase (SBP) is a peroxidase with extraordinary stability and catalytic properties. It belongs to the family of class III plant peroxidases that can oxidize a wide variety of organic and inorganic substrates using hydrogen peroxide. Because the plant enzyme is a heterogeneous...

  19. PLANT SPACING AND WEED MANAGEMENT TECHNIQUES INFLUENCE WEED COMPETITIVENESS OF DRUM SEEDED RICE (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    B N Sandeep Nayak

    2014-11-01

    Full Text Available Direct wet seeded-rice sown through drum seeder, a potential wise rice production system in the present-day scenario, is subject to severe weed infestation and, therefore, development of a sustainable weed management strategy is crucial for its wide spread adoption. The present study was conducted in kharif 2012 at department of agronomy division with NLR-33358 (SOMASILA using six planting densities under five weed management conditions. The plant spacing tried were: 20cm x 7cm, 20 cm x 10.5 cm, 20 cm x 14 cm, 20 cm x 17.5 cm and 20 cm x 24.5cm and 20 cm x15cm. with a plant density of 71, 47, 35, 28, 20 and 33 hills m-2, respectively and five weed management practices viz., weedy check (W1, hand weeding at 20 and 40 DAS (W2, cono weeding at 20 and 40 with modified cono weeder (W3, pre-emergence application of anilofos @ 0.375 kg a.i ha-1 followed by post-emergence application of 2, 4 D sodium salt @ 1.0 kg a.i ha-1 20-25 DAS (W4, pre-emergence application of pendimethalin @1.0 kg a.i ha-1 followed by post-emergence application of bispyribac sodium @ 20 g a.i ha-1 30 DAS ( W5. . The experiment was laid out in strip- plot design with three replications assigning weed management techniques in vertical factor and plant spacing in horizontal factor. Direct wet seeded rice field was infested with 12 and 22 weed species, kharif -2012 season having Echinochloa colona, Leptochloa chinensis, Digitaria aescendens, Cyperus iriaand Eleusine indicaas the predominant weeds. Rice spacing exerted significant influence on both weed pressure and yield performance of crop. With the increase in plant spacing weed dry matter decreased but rice yield increased. In this season, among different plant densities, the highest density of 71 hills m-2(D1 resulted in minimum weed density, weed drymatter, and more number of tillers m-2 and maximum drymatter production at all stages of plant growth. closest spacing resulted in maximum weed suppression, but among various rice

  20. Ethylene reduces plant gas exchange and growth of lettuce grown from seed to harvest under hypobaric and ambient total pressure.

    Science.gov (United States)

    He, Chuanjiu; Davies, Fred T

    2012-03-01

    Naturally occurring high levels of ethylene can be a problem in spaceflight and controlled environment agriculture (CEA) leading to sterility and irregular plant growth. There are engineering and safety advantages of growing plants under hypobaria (low pressure) for space habitation. The goals of this research were to successfully grow lettuce (Lactuca sativa cv. Buttercrunch) in a long-term study from seed to harvest under hypobaric conditions, and to investigate how endogenously produced ethylene affects gas exchange and plant growth from seed germination to harvest under hypobaric and ambient total pressure conditions. Lettuce was grown under two levels of total gas pressure [hypobaric or ambient (25 or 101 kPa)] in a long-term, 32-day study. Significant levels of endogenous ethylene occurred by day-15 causing reductions in photosynthesis, dark-period respiration, and a subsequent decrease in plant growth. Hypobaria did not mitigate the adverse ethylene effects on plant growth. Seed germination was not adversely affected by hypobaria, but was reduced by hypoxia (6 kPa pO(2)). Under hypoxia, seed germination was higher under hypobaria than ambient total pressure. This research shows that lettuce can be grown from seed to harvest under hypobaria (≅25% of normal earth ambient total pressure). Copyright © 2011 Elsevier GmbH. All rights reserved.

  1. Evolution of the PEBP Gene Family in Plants: Functional Diversification in Seed Plant Evolution

    National Research Council Canada - National Science Library

    Anna Karlgren; Nielas Gyllenstrand; Thomas Källman; Jens F. Sundström; David Moore; Martin Lascoux; Ulf Lagercrantz

    2011-01-01

    ...], MOTHER OF FT AND TFL1 [MFT], and TERMINAL FLOWER1 [TFL1] like). In angiosperms, PEBP genes have been shown to function both as promoters and suppressors of flowering and to control plant architecture...

  2. Stimulating and inactivating effects of microwave processing on plant seeds and associated with them microflora and microorganisms

    OpenAIRE

    Morozov, Gennadiy A.; Stakhova, N. Ye.; Shangaraeva, Ya. N.

    2014-01-01

    This article discusses the technology and presents the effects of stimulating pre-planting treatment of cereal crop seeds (wheat) and softwood (pine, spruce) by the electromagnetic waves energy of decimeter and millimeter ranges; it also discusses the use of features and results of microwave technologies employed for treatment of seeds before putting them into storage, and soils, secondary soil and water, used for their disembarkation, in order to inactivate pathogenic microbiological organis...

  3. 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

  4. Direct Gene Transfer into Plant Mature Seeds via Electroporation After Vacuum Treatment

    Science.gov (United States)

    Hagio, Takashi

    A number of direct gene transfer methods have been used successfully in plant genetic engineering, providing powerful tools to investigate fundamental and applied problems in plant biology (Chowrira et al., 1996; D'halluin et al., 1992; Morandini and Salamini, 2003; Rakoczy-Trojanowska, 2002; Songstad et al., 1995). In cereals, several methods have been found to be suitable for obtaining transgenic plant; these include bombardment of scutellum (Hagio et al., 1995) and inflorescence cultures (He et al., 2001), and silicon carbide fiber-mediated DNA delivery (Asano et al., 1991) and Agrobacterium tumefaciens transformation (Potrykus, 1990). Electroporation of cereal protoplasts also has proved successful but it involves prolonged cell treatments and generally is limited by the difficulties of regeneration from cereal protoplast cultures (Fromm et al., 1987). Many laboratories worldwide are now using Agrobacterium as a vehicle for routine production of transgenic crop plants. The primary application of the particle system (Klein et al., 1987) has been for transformation of species recalcitrant to conventional Agrobacterium (Binns, 1990) or protoplast methods. But these conventional methods can be applied to the species and varieties that are amenable to tissue culture (Machii et al., 1998). Mature seeds are readily available and free from the seasonal limits that immature embryo, inflorescence, and anther have. This method enables us to produce transgenic plants without time-consuming tissue culture process.

  5. An Effective System to Produce Smoke Solutions from Dried Plant Tissue for Seed Germination Studies

    Directory of Open Access Journals (Sweden)

    Janice Coons

    2014-02-01

    Full Text Available Premise of the study: An efficient and inexpensive system was developed to produce smoke solutions from plant material to research the influence of water-soluble compounds from smoke on seed germination. Methods and Results: Smoke solutions (300 mL per batch were produced by burning small quantities (100–200 g of dried plant material from a range of species in a bee smoker attached by a heater hose to a side-arm flask. The flask was attached to a vacuum water aspirator, to pull the smoke through the water. The entire apparatus was operated in a laboratory fume hood. Conclusions: Compared with other smoke solution preparation systems, the system described is easy to assemble and operate, inexpensive to build, and effective at producing smoke solutions from desired species in a small indoor space. Quantitative measurements can be made when using this system, allowing for replication of the process.

  6. {sup 134}Cs in heather seed plants grown with and without mycorrhiza

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, M. [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Johansson, M. [Department of Mycology, Botanical Institute, University of Copenhagen, Oester Farimagsgade 2D, DK-1353 Copenhagen K. (Denmark)

    1988-08-01

    Experiments were carried out to determine differences between mycorrhized and non-mycorrhized seed plants of heather, Calluna vulgaris(L)Hull, as regards the uptake of {sup 134}Cs. In most treatments heather with mycorrhiza had a significantly higher transfer of {sup 134}Cs to the shoots than heather without mycorrhiza. As an average the concentration of {sup 134}Cs was 18% higher in the mycorrhized plants than in the non-mycorrhized. Application of 10 kg K/ha reduced the concentration of {sup 134}Cs in shoots of heather by 49% as an average. Because of improved growth in the potassium fertilized pots the reduction viewed on the basis of the area was only 33%. Nitrogen application does not significantly influence the concentration of {sup 134}Cs in shoots of heather regardless of mycorrhizal status. (Copyright (c) 1988 Elsevier Science B.V., Amsterdam. All rights reserved.)

  7. Rice Seed Priming with Picomolar Rutin Enhances Rhizospheric Bacillus subtilis CIM Colonization and Plant Growth.

    Science.gov (United States)

    Singh, Akanksha; Gupta, Rupali; Pandey, Rakesh

    2016-01-01

    The effect of rutin, a bioflavonoid on the growth and biofilm formation of Bacillus subtilis strain CIM was investigated. In addition to swimming, swarming, and twitching potentials of B. subtilis CIM (BS), one picomolar (1 pM) of rutin was also observed to boost the biofilm forming ability of the bacterium. Bio-priming of rice seeds with BS and rutin not only augmented root and shoot lengths but also the photosynthetic pigments like chlorophyll and carotenoid. Similarly, high accumulation of phenolic and flavonoid contents was observed in the leaves. Fluorescent microscopic images revealed that BS plus rutin enhanced callose deposition in the leaves. It was also established that the least formation of reactive oxygen species in BS plus rutin treated rice plants was due to higher free radicals scavenging activity and total antioxidant potential. The results highlight chemo attractant nature of BS towards rutin, which by enhancing biofilm formation and root colonization indirectly strengthened the plants' defensive state.

  8. APPLICATION OF PLANT GROWTH-PROMOTING RHIZOBACTERIA TO RUNNER BEAN INCREASES SEED CARBOHYDRATE AND PROTEIN YIELD

    Directory of Open Access Journals (Sweden)

    Marius Stefan

    2013-08-01

    Full Text Available The potential of two rhizobacterial strains with plant growth promoting capabilities (mineral phosphate solubilization and IAA production traits to influence the nutritive value of runner bean grains was assessed on plants cultivated in organic crop system. Seed inoculation with rhizobacterial strains improve the nutritive value of the harvested grains by enhancing the soluble protein content up to 11.97 % and total reducing carbohydrates content up to 28.97%. The number of fractions detected by SDS-PAGE analysis in the all extracts was around 20, without any significant differences between the control and the inoculated samples. Our study suggests that the two PGPR strains may be used as biofertilizer for vegetable production in sustainable and ecological agricultural systems.

  9. Rice Seed Priming with Picomolar Rutin Enhances Rhizospheric Bacillus subtilis CIM Colonization and Plant Growth.

    Directory of Open Access Journals (Sweden)

    Akanksha Singh

    Full Text Available The effect of rutin, a bioflavonoid on the growth and biofilm formation of Bacillus subtilis strain CIM was investigated. In addition to swimming, swarming, and twitching potentials of B. subtilis CIM (BS, one picomolar (1 pM of rutin was also observed to boost the biofilm forming ability of the bacterium. Bio-priming of rice seeds with BS and rutin not only augmented root and shoot lengths but also the photosynthetic pigments like chlorophyll and carotenoid. Similarly, high accumulation of phenolic and flavonoid contents was observed in the leaves. Fluorescent microscopic images revealed that BS plus rutin enhanced callose deposition in the leaves. It was also established that the least formation of reactive oxygen species in BS plus rutin treated rice plants was due to higher free radicals scavenging activity and total antioxidant potential. The results highlight chemo attractant nature of BS towards rutin, which by enhancing biofilm formation and root colonization indirectly strengthened the plants' defensive state.

  10. In silico identification and comparative genomics of candidate genes involved in biosynthesis and accumulation of seed oil in plants.

    Science.gov (United States)

    Sharma, Arti; Chauhan, Rajinder Singh

    2012-01-01

    Genes involved in fatty acids biosynthesis, modification and oil body formation are expected to be conserved in structure and function in different plant species. However, significant differences in the composition of fatty acids and total oil contents in seeds have been observed in different plant species. Comparative genomics was performed on 261 genes involved in fatty acids biosynthesis, TAG synthesis, and oil bodies formation in Arabidopsis, Brassica rapa, castor bean and soybean. In silico expression analysis revealed that stearoyl desaturase, FatB, FAD2, oleosin and DGAT are highly abundant in seeds, thereby considered as ideal candidates for mining of favorable alleles in natural population. Gene structure analysis for major genes, ACCase, FatA, FatB, FAD2, FAD3 and DGAT, which are known to play crucial role in oil synthesis revealed that there are uncommon variations (SNPs and INDELs) which lead to varying content and composition of fatty acids in seed oil. The predicted variations can provide good targets for seed oil QTL identification, understanding the molecular mechanism of seed oil accumulation, and genetic modification to enhance seed oil yield in plants.

  11. In Silico Identification and Comparative Genomics of Candidate Genes Involved in Biosynthesis and Accumulation of Seed Oil in Plants

    Directory of Open Access Journals (Sweden)

    Arti Sharma

    2012-01-01

    Full Text Available Genes involved in fatty acids biosynthesis, modification and oil body formation are expected to be conserved in structure and function in different plant species. However, significant differences in the composition of fatty acids and total oil contents in seeds have been observed in different plant species. Comparative genomics was performed on 261 genes involved in fatty acids biosynthesis, TAG synthesis, and oil bodies formation in Arabidopsis, Brassica rapa, castor bean and soybean. In silico expression analysis revealed that stearoyl desaturase, FatB, FAD2, oleosin and DGAT are highly abundant in seeds, thereby considered as ideal candidates for mining of favorable alleles in natural population. Gene structure analysis for major genes, ACCase, FatA, FatB, FAD2, FAD3 and DGAT, which are known to play crucial role in oil synthesis revealed that there are uncommon variations (SNPs and INDELs which lead to varying content and composition of fatty acids in seed oil. The predicted variations can provide good targets for seed oil QTL identification, understanding the molecular mechanism of seed oil accumulation, and genetic modification to enhance seed oil yield in plants.

  12. Overexpression of patatin-related phospholipase AIIIδ altered plant growth and increased seed oil content in camelina.

    Science.gov (United States)

    Li, Maoyin; Wei, Fang; Tawfall, Amanda; Tang, Michelle; Saettele, Allison; Wang, Xuemin

    2015-08-01

    Camelina sativa is a Brassicaceae oilseed species being explored as a biofuel and industrial oil crop. A growing number of studies have indicated that the turnover of phosphatidylcholine plays an important role in the synthesis and modification of triacylglycerols. This study manipulated the expression of a patatin-related phospholipase AIIIδ (pPLAIIIδ) in camelina to determine its effect on seed oil content and plant growth. Constitutive overexpression of pPLAIIIδ under the control of the constitutive cauliflower mosaic 35S promoter resulted in a significant increase in seed oil content and a decrease in cellulose content. In addition, the content of major membrane phospholipids, phosphatidylcholine and phosphatidylethanolamine, in 35S::pPLAIIIδ plants was increased. However, these changes in 35S::pPLAIIIδ camelina were associated with shorter cell length, leaves, stems, and seed pods and a decrease in overall seed production. When pPLAIIIδ was expressed under the control of the seed specific, β-conglycinin promoter, the seed oil content was increased without compromising plant growth. The results suggest that pPLAIIIδ alters the carbon partitioning by decreasing cellulose content and increasing oil content in camelina. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  13. Protective effects of plant seed extracts against amyloid β-induced neurotoxicity in cultured hippocampal neurons

    Directory of Open Access Journals (Sweden)

    Yoshinori Okada

    2013-01-01

    Full Text Available Aim: Alzheimer′s disease (AD is characterized by large deposits of amyloid β (Aβ peptide. Aβ is known to increase reactive oxygen species (ROS production in neurons, leading to cell death. In this study, we screened 15 plant seeds′ aqueous extracts (PSAE for inhibitory effects on Aβ (25-35-induced cell death using hippocampus neurons (HIPN. Materials and Methods: Fifteen chosen plants were nine medical herbs (Japanese honeywort, luffa, rapeseed, Chinese colza, potherb mustard, Japanese radish, bitter melon, red shiso, corn, and kaiware radish and six general commercial plants (common bean, komatsuna, Qing geng cai, bell pepper, kale, and lettuce. PSAE were measured for total phenolic content (TPC with the Folin-Ciocalteu method, and the 2-diphenyl-1-picryl-hydrazyl (DPPH radical scavenging effect of each seed extract was measured. To find a protectant against Aβ-induced oxidative stress, we screened 15 PSAE using a 2′, 7′-dichlorofluorescein diacetate assay. To further unravel the anti-inflammatory effects of PSAE on Aβ-induced inflammation, PSAE were added to HIPN. The neuroprotective effects of the PSAE were evaluated by Cell Counting Kit-8 assay, measuring the cell viability in Aβ-induced HIPN. Results: TPC of 15 PSAE was in the range of 0.024-1.96 mg of chlorogenic acid equivalents/gram. The aqueous extracts showed antioxidant activities. Furthermore, intracellular ROS accumulation resulting from Aβ treatment was reduced when cells were treated with some PSAE. Kale, bitter melon, kaiware radish, red shiso, and corn inhibited tumor necrosis factor-alpha secretion by the Aβ-stimulated neurons and all samples except Japanese honeywort showed enhancement of cell survival. Conclusion: From these results, we suggest that some plant seed extracts offer protection against Aβ-mediated cell death.

  14. Limitations of biodiversity databases: case study on seed-plant diversity in Tenerife, Canary Islands.

    Science.gov (United States)

    Hortal, Joaquín; Lobo, Jorge M; Jiménez-Valverde, Alberto

    2007-06-01

    Databases on the distribution of species can be used to describe the geographic patterns of biodiversity. Nevertheless, they have limitations. We studied three of these limitations: (1) inadequacy of raw data to describe richness patterns due to sampling bias, (2) lack of survey effort assessment (and lack of exhaustiveness in compiling data about survey effort), and (3) lack of coverage of the geographic and environmental variations that affect the distribution of organisms. We used a biodiversity database (BIOTA-Canarias) to analyze richness data from a well-known group (seed plants) in an intensively surveyed area (Tenerife Island). Observed richness and survey effort were highly correlated. Species accumulation curves could not be used to determine survey effort because data digitalization was not exhaustive, so we identified well-sampled sites based on observed richness to sampling effort ratios. We also developed a predictive model based on the data from well-sampled sites and analyzed the origin of the geographic errors in the obtained extrapolation by means of a geographically constrained cross-validation. The spatial patterns of seed-plant species richness obtained from BIOTA-Canarias data were incomplete and biased. Therefore, some improvements are needed to use this database (and many others) in biodiversity studies. We propose a protocol that includes controls on data quality, improvements on data digitalization and survey design to improve data quality, and some alternative data analysis strategies that will provide a reliable picture of biodiversity patterns.

  15. USE MANURE AND ORGANIC WASTE AS PLANTING MEDIA OF SEED POTATOES PRODUCTION

    Directory of Open Access Journals (Sweden)

    Meksy Dianawati

    2014-02-01

    Full Text Available Manure and organic waste could be used as organic media at potato seed production of G1. The goal of this research was to increase production of potato seed G1 by several kinds of manure and organic waste. This research was conducted at plastic house in Lembang, West Java, from June to September 2014. This research used randomized completed block design with two treatment factors and six replications. The first factor was kinds of manure i.e chicken manure and sheep manure. The second factor was kinds of organic waste. Data was analysed by F test and followed by Duncan and correlation test at 95 percent confidence level. The results showed that media of husk waste with chicken and sheep manure has higher tuber weight and number of big-size tuber per plant than one of cocopeat significantly. Media of sheep manure with husk and bamboo waste has highest tuber weight per plant significantly. Number of total tuber was effected by number of smallsized tuber by 84 percent.

  16. Seed specific expression and analysis of recombinant human adenosine deaminase (hADA) in three host plant species.

    Science.gov (United States)

    Doshi, Ketan M; Loukanina, Natalia N; Polowick, Patricia L; Holbrook, Larry A

    2016-10-01

    The plant seed is a leading platform amongst plant-based storage systems for the production of recombinant proteins. In this study, we compared the activity of human adenosine deaminase (hADA) expressed in transgenic seeds of three different plant species: pea (Pisum sativum L.), Nicotiana benthamiana L. and tarwi (Lupinus mutabilis Sweet). All three species were transformed with the same expression vector containing the hADA gene driven by the seed-specific promoter LegA2 with an apoplast targeting pinII signal peptide. During the study, several independent transgenic lines were generated and screened from each plant species and only lines with a single copy of the gene of interest were used for hADA expression analysis. A stable transgenic canola line expressing the ADA protein, under the control of 35S constitutive promoter was used as both as a positive control and for comparative study with the seed specific promoter. Significant differences were detected in the expression of hADA. The highest activity of the hADA enzyme (Units/g seed) was reported in tarwi (4.26 U/g) followed by pea (3.23 U/g) and Nicotiana benthamiana (1.69 U/g). The expression of mouse ADA in canola was very low in both seed and leaf tissue compared to other host plants, confirming higher activity of seed specific promoter. Altogether, these results suggest that tarwi could be an excellent candidate for the production of valuable recombinant proteins.

  17. Effect of Radiation on Seed Germinating Ability Ofwild-Growing and Cultivated Plants, Sources of Bioactive Substances

    Science.gov (United States)

    Shabanov, Aleksandr; Tirranen, Lyalya; Zykova, Irina; Bondarenko, Gennadiy

    2016-07-01

    In the above-ground parts of common chickweed (Stellaria media) the content of vitamin C was experimentally quantified, which (in terms of dry matter) was 81.55 mg/100 g; 133 mg/100 g and 161.76 mg/100 g depending on the growing site. 52 components were detected in the essential oil of the above-ground parts of common chickweed (Stellaria media). Chamazulene, neophytodien and phytol are the major components of whole oil. A wide range of elements was identified in the plants and seeds of common chickweed (Stellaria media), and in the seeds of carrots, parsley and lettuce. It was established that UV irradiation (lamp with a wavelength of 254 nm and 283 nm) of chickweed seeds (Stellaria media) for 15 sec. and 100 sec. in a microbiological box on a table at a distance from the object didn't affect their germinating ability. The germinating ability of the experimental seeds was identical to the control (no irradiation) seeds. With the help of an X-ray fluorescence spectrometer Renger 2 (Germany) at a voltage of 1.6 kV during 15 sec. the effect of "soft" radiation on the seed germinating ability of chickweed, carrot, parsley and lettuce seeds was studied.Under the effect of "soft" radiation during 15 sec. all the experimental chickweed seeds sprouted, like in the control. The germinating ability of the exposed lettuce seeds was 100% after one day, while only 45% of the exposed parsley seeds grew after 21 days. The exposed carrot seeds (70%) grew after 18 days. The effect of "hard" radiation on the germinating ability of common chickweed seeds was investigated using an X-ray fluorescence spectrometer S4 Pioneer (Germany) at a voltage of 60 kV for 15 sec and 100 sec. Under the effect of "hard" radiation and during 15 seconds of exposure, where the distance (L) from the focus of the X-ray tube to the seeds of chickweed was 20 mm, the germinating ability of the experimental chickweed seeds was 30 %. At a voltage of 60 kV and 100-second exposure the germinating ability of the

  18. Survival of plant seeds, their UV screens, and nptII DNA for 18 months outside the International Space Station.

    Science.gov (United States)

    Tepfer, David; Zalar, Andreja; Leach, Sydney

    2012-05-01

    The plausibility that life was imported to Earth from elsewhere can be tested by subjecting life-forms to space travel. Ultraviolet light is the major liability in short-term exposures (Horneck et al., 2001 ), and plant seeds, tardigrades, and lichens-but not microorganisms and their spores-are candidates for long-term survival (Anikeeva et al., 1990 ; Sancho et al., 2007 ; Jönsson et al., 2008 ; de la Torre et al., 2010 ). In the present study, plant seeds germinated after 1.5 years of exposure to solar UV, solar and galactic cosmic radiation, temperature fluctuations, and space vacuum outside the International Space Station. Of the 2100 exposed wild-type Arabidopsis thaliana and Nicotiana tabacum (tobacco) seeds, 23% produced viable plants after return to Earth. Survival was lower in the Arabidopsis Wassilewskija ecotype and in mutants (tt4-8 and fah1-2) lacking UV screens. The highest survival occurred in tobacco (44%). Germination was delayed in seeds shielded from solar light, yet full survival was attained, which indicates that longer space travel would be possible for seeds embedded in an opaque matrix. We conclude that a naked, seed-like entity could have survived exposure to solar UV radiation during a hypothetical transfer from Mars to Earth. Chemical samples of seed flavonoid UV screens were degraded by UV, but their overall capacity to absorb UV was retained. Naked DNA encoding the nptII gene (kanamycin resistance) was also degraded by UV. A fragment, however, was detected by the polymerase chain reaction, and the gene survived in space when protected from UV. Even if seeds do not survive, components (e.g., their DNA) might survive transfer over cosmic distances.

  19. Differential inactivation of seed exudate stimulation of Pythium ultimum sporangium germination by Enterobacter cloacae influences biological control efficacy on different plant species.

    Science.gov (United States)

    Kageyama, Koji; Nelson, Eric B

    2003-02-01

    This study was initiated to understand whether differential biological control efficacy of Enterobacter cloacae on various plant species is due to differences in the ability of E. cloacae to inactivate the stimulatory activity of seed exudates to Pythium ultimum sporangium germination. In biological control assays, E. cloacae was effective in controlling Pythium damping-off when placed on the seeds of carrot, cotton, cucumber, lettuce, radish, tomato, and wheat but failed to protect corn and pea from damping-off. Seeds from plants such as corn and pea had high rates of exudation, whereas cotton and cucumber seeds had much lower rates of exudation. Patterns of seed exudation and the release of P. ultimum sporangium germination stimulants varied among the plants tested. Seed exudates of plants such as carrot, corn, lettuce, pea, radish, and wheat were generally more stimulatory to P. ultimum than were the exudates of cotton, cucumber, sunflower, and tomato. However, this was not directly related to the ability of E. cloacae to inactivate the stimulatory activity of the exudate and reduce P. ultimum sporangium germination. In the spermosphere, E. cloacae readily reduced the stimulatory activity of seed exudates from all plant species except corn and pea. Our data have shown that the inability of E. cloacae to protect corn and pea seeds from Pythium damping-off is directly related to its ability to inactivate the stimulatory activity of seed exudates. On all other plants tested, E. cloacae was effective in suppressing damping-off and inactivating the stimulatory activity of seed exudates.

  20. Disturbance frequency and vertical distribution of seeds affect long-term population dynamics: a mechanistic seed bank model.

    Science.gov (United States)

    Eager, Eric Alan; Haridas, Chirakkal V; Pilson, Diana; Rebarber, Richard; Tenhumberg, Brigitte

    2013-08-01

    Seed banks are critically important for disturbance specialist plants because seeds of these species germinate only in disturbed soil. Disturbance and seed depth affect the survival and germination probability of seeds in the seed bank, which in turn affect population dynamics. We develop a density-dependent stochastic integral projection model to evaluate the effect of stochastic soil disturbances on plant population dynamics with an emphasis on mimicking how disturbances vertically redistribute seeds within the seed bank. We perform a simulation analysis of the effect of the frequency and mean depth of disturbances on the population's quasi-extinction probability, as well as the long-term mean and variance of the total density of seeds in the seed bank. We show that increasing the frequency of disturbances increases the long-term viability of the population, but the relationship between the mean depth of disturbance and the long-term viability of the population are not necessarily monotonic for all parameter combinations. Specifically, an increase in the probability of disturbance increases the long-term viability of the total seed bank population. However, if the probability of disturbance is too low, a shallower mean depth of disturbance can increase long-term viability, a relationship that switches as the probability of disturbance increases. However, a shallow disturbance depth is beneficial only in scenarios with low survival in the seed bank.

  1. Effects of frugivore impoverishment and seed predators on the recruitment of a keystone palm

    Science.gov (United States)

    Fadini, Rodrigo F.; Fleury, Marina; Donatti, Camila I.; Galetti, Mauro

    2009-03-01

    Many plant species are threatened as a result of extinction of their large-bodied frugivores all over the world. Additionally, introduced herbivores and seed predators may cause severe pressure on early stages of plant recruitment. We studied the seed dispersal and seed predation of the keystone palm Euterpe edulis on a land-bridge island with a highly impoverished frugivore fauna and overabundant seed predators, and in a continuous Atlantic forest in Brazil. While the diversity of avian seed dispersers and predators was higher on the mainland, the abundance of seed dispersers was 4-fold higher on the island. Turdus flavipes was responsible for 72% and 96% of seeds removed in the island and mainland, respectively. However, the higher density of T. flaviceps on the island did not result in higher seed removal. In fact, seed removal rate was 1.7 times lower there than on the mainland, probably due to the aggressive behavior of the major seed disperser who defend palm fruits. Seed predation, on the other hand, was markedly higher on the island, where nearly 100% of seeds were preyed upon, but only 0.3% on the mainland. As a consequence of higher seed predation the population of E. edulis has few numbers of seedlings and saplings on the island. Therefore, management of the seed predator populations on the island is a key priority for recovering the natural population of this keystone palm and the frugivores that depend on its fruits.

  2. Choices and consequences of oviposition by a pollinating seed predator, Hadena ectypa (Noctuidae), on its host plant, Silene stellata (Caryophyllaceae).

    Science.gov (United States)

    Kula, Abigail A R; Dudash, Michele R; Fenster, Charles B

    2013-06-01

    Pollinating seed predators are models for the study of mutualisms. These insects have dual effects on host-plant fitness, through pollination as adults and flower and fruit predation as larvae. A rarely examined question is whether pollinating seed-predator oviposition choices are influenced by plant floral and size traits and the potential consequences of oviposition for host-plant reproduction. • We quantified oviposition by a pollinating seed predator, Hadena ectypa, on its host, Silene stellata, to determine if oviposition was associated with specific plant traits and whether oviposition was significantly correlated with fruit initiation or flower and fruit predation over three years. We also quantified whether stigmatic pollen loads of flowers visited by Hadena that both fed on nectar and oviposited were greater than when Hadena only fed on nectar. • Hadena had significant preference for plants having flowers with long corolla tubes in all three years. Moth oviposition was correlated with other traits only in some years. Oviposition did not increase stigmatic pollen loads. We observed significant positive relationships between both oviposition and fruit initiation and oviposition and flower/fruit predation. • Hadena ectypa oviposition choices were based consistently on floral tube length differences among individuals, and the consequences of oviposition include both fruit initiation (due to pollination while feeding on nectar prior to oviposition) and larval flower/fruit predation. The positive association between oviposition and fruit initiation may explain the long-term maintenance of facultative pollinating seed-predator interactions.

  3. The effect of plant growth regulators, nitric oxide, nitrate, nitrite and light on the germination of dimorphic seeds of Suaeda salsa under saline conditions.

    Science.gov (United States)

    Li, Weiqiang; Liu, Xiaojing; Ajmal Khan, M; Yamaguchi, Shinjiro

    2005-06-01

    Suaeda salsa, a leaf succulent shrub in the family Chenopodiaceae, is one of the most important halophytes in China. Suaeda salsa produces dimorphic seeds (soft brown seeds and hard black seeds). Seeds of S. salsa were collected from the coastal salt flats near Huanghua City, China. Experiments were conducted to determine the salinity-alleviating effect of plant growth regulators, nitric oxide, nitrate, nitrite and light on the germination of dimorphic seeds of S. salsa. Brown seeds had a higher germination rate than black seeds in all experiments. Black seeds were more sensitive to salt in the absence of light in comparison to brown seeds. Brown seeds absorbed water more quickly in comparison to black seeds and were found to be more tolerant of salt stress. Our results showed that 1-aminocyclopropane-1-carboxylate (ACC, the immediate precursor of ethylene), nitrite, GA(4) and BA improved seed germination in the presence of salt. However, nitrate, GA(1), GA(3) failed to alleviate salt stress. ABA inhibited seed germination and seedling growth. Possible mechanisms involved in the alleviation of salt stress in S. salsa seeds and the ecological adaptation of the seeds to the environment are discussed.

  4. Nitrogen, potassium and plant growth retardant effects on oil content and quality of cotton seed

    Directory of Open Access Journals (Sweden)

    Alkassas, A. R.

    2007-09-01

    Full Text Available The aim of this field experiment was to investigate the effect of nitrogen, potassium and a plant growth retardant (PGR on seed yield and protein and oil content of an Egyptian cotton cultivar (Gossypium barbadense Giza 86. Treatments consisted of: soil application of N (95 and 143 kg N ha-1 in the form ammonium nitrate, foliar application of potassium (0, 319, 638 or 957 g K ha-1 as potassium sulfate and foliar application of mepiquat chloride (MC (0 and 48 + 24 g active ingredient ha-1 on seed, protein and oil yields and oil properties of Egyptian cotton cultivar “Giza 86” (Gossypium barbadense. After applying the higher N-rate, foliar application of potassium and plant growth retardant MC significantly increased seed yield and the content of seed protein and oil, seed oil refractive index, unsaponifiable matter and total unsaturated fatty acids (oleic and linoleic. In contrast, oil acid and saponification value as well as total saturated fatty acids were decreased by foliar application of potassium and MC. The seed oil content was decreased with soil application of N.El objetivo de los experimentos de campo fue investigar el efecto del nitrogeno, potasio y retardantes del crecimiento de plantas sobre el contenido en proteínas y aceite de una semilla de algodón cultivada en Egipto (Gossypium barbadense Giza 86. Los tratamientos consistieron en la aplicación en suelo de N (95 and 143 kg N ha-1 en forma de nitrato amónico, aplicación foliar de K (0, 319, 638 or 957 g K ha-1 como sulfato potásico y aplicación foliar de cloruro de m mepiquat (MC (0 and 48 + 24 g de ingrediente activo ha-1 sobre un cultivar de algodón «Giza 86» (Gossypium barbadense. La aplicación de la cantidad más elevada de N, unida a la aplicación de potasio y del retardador MC, aumentó significativamente el rendimiento en semilla, así como el contenido en proteinas y en aceite. Respecto al aceite, aumentó el índice de refracción, la fracci

  5. International Seed Testing Association List of stabilized plant names, edition 6

    Science.gov (United States)

    Seed-testing laboratories determine the quality of seed lots in national and international seed commerce. Those services most commonly requested include purity analysis, noxious-weed seed detection, and viability tests. Rigorous procedures for performing various tests on specific crops have been est...

  6. Seed retention by pioneer trees enhances plant diversity resilience on gravel bars: Observations from the river Allier, France

    Science.gov (United States)

    Corenblit, Dov; Vidal, Vincent; Cabanis, Manon; Steiger, Johannes; Garófano-Gómez, Virginia; Garreau, Alexandre; Hortobágyi, Borbála; Otto, Thierry; Roussel, Erwan; Voldoire, Olivier

    2016-07-01

    Pioneer riparian trees which establish in river active tracts on gravel bars enhance fine sediment retention during high flows within their stands and in their lee side, forming obstacle marks. Fine sediment retention can be accompanied by deposition of seeds transported by water dispersal, i.e. by hydrochory. We tested the hypothesis that pioneer riparian trees significantly control seed deposition on gravel bars by forming sediment obstacle marks. We described the seed bank structure and compared samples collected from obstacle marks and bare coarse-grained bar surfaces. At the surface (at 2 cm depth), seed abundance (N) and richness (S) (expressed as mean ± sd) were significantly higher in areas directly affected by riparian trees, i.e. obstacle marks, (N: 693 ± 391; S: 17 ± 3) than in bare surfaces (N: 334 ± 371; S: 13 ± 5). Surface and sub-surface (at 20 cm depth) samples were also significantly different, with the sub-surface samples almost devoid of seeds (respectively N: 514 ± 413; S: 15 ± 5 and N: 3 ± 6; S: 1 ± 2). These results suggest a biogeomorphic feedback between sediment and associated seed retention mediated by hydrochory, vegetation growth and local seed dispersal mediated by barochory. Such feedback may improve plant diversity resilience on gravel alluvial bars of high-energy rivers.

  7. Germination behaviour of seeds from herbicide treated plants of Chenopodium album L.

    Directory of Open Access Journals (Sweden)

    Asif Tanveer

    2009-12-01

    Full Text Available The carry-over effect of sub-lethal herbicides was investigated on the germination of seeds collected from surviving Chenopodium album plants, which had received 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 doses of either pre-emergence ioxynil or post-emergence bentazone in a previous onion (Allium cepa crop. Seeds were also collected from surviving C. album plants, which had received 1/4, 1/2, 1/1 of either pre-emergence pendimethalin, propachlor and linuron, or 1/8, 1/8 twice, 1/8 three times, 1/4, 1/2, 1/1 of post-emergence ioxynil or linuron in a previous leek (Allium porrum crop. Seeds of surviving plants were collected and tested for germination at temperature of 5, 10, 15, 20 and 25°C. The effect of different temperatures on the total number of germinated seeds was significant. Germination was minimum at low temperatures (5°C or 10°C. Herbicides did not show any effect on germination of C. album and resulted in the same final germination percentage as seeds collected from the unsprayed control plots.Avaliou-se o efeito residual de doses sub-letais de herbicidas sobre a germinação de sementes de plantas de Chenopodium album sobreviventes em uma cultura prévia de cebola (Allium cepa, que recebeu 2x, 3x, 1/4, 1/2 ou a dose recomendada de ioxynil em pré-emergência ou bentazone em pós-emergência. As sementes foram também coletadas de plantas de C. album sobreviventes de um campo de alho-porró (Allium porrum que havia sido tratado com 1/4, 1/2 ou a dose recomendada de pendimethalin, propachlor e linuron em pré-emergência, ou ainda 2x, 3x, 1/4, 1/2 ou a dose recomendada de ioxynil ou linuron em pós-emergência. As sementes destas plantas sobreviventes foram coletadas e testadas quanto à germinação a temperaturas de 5°C, 10°C, 15°C, 20°C e 25°C. Verificou-se que o efeito das temperaturas na germinação destas sementes foi significativa. A germinação foi mínima a baixas temperaturas (5°C e 10°C. Os herbicidas n

  8. Food Safety by Using Machine Learning for Automatic Classification of Seeds of the South-American Incanut Plant

    Science.gov (United States)

    Lemanzyk, Thomas; Anding, Katharina; Linss, Gerhard; Rodriguez Hernández, Jorge; Theska, René

    2015-02-01

    The following paper deals with the classification of seeds and seed components of the South-American Incanut plant and the modification of a machine to handle this task. Initially the state of the art is being illustrated. The research was executed in Germany and with a relevant part in Peru and Ecuador. Theoretical considerations for the solution of an automatically analysis of the Incanut seeds were specified. The optimization of the analyzing software and the separation unit of the mechanical hardware are carried out with recognition results. In a final step the practical application of the analysis of the Incanut seeds is held on a trial basis and rated on the bases of statistic values.

  9. Influence of planting date on seed protein oil sugars minerals and nitrogen metabolism in soybean under irrigated and non-irrigated enviroments

    Science.gov (United States)

    Information on the effect of planting date and irrigation on soybean [Glycine max (L.) Merr.] seed composition in the Early Soybean Production System is deficient, and what is available is inconclusive. The objective of this research was to investigate the effects of planting date on seed protein, o...

  10. Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

    Directory of Open Access Journals (Sweden)

    Cíntia Alvarenga Santos Fraga de Miranda

    2015-07-01

    Full Text Available In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the allelopathic potential of essential oils extracted from fresh leaves of lemon grass (Cymbopogon citratus, wild basil (Ocimum gratissimum L. and sweet basil (Ocimum basilicum L. with regard to their major constituents (citral, eugenol and cineol, respectively in different application forms (direct contact and the effect of volatile constituents on the germination and vigor of lettuce seeds (cultivar Regina SF 3500. The effects of the oils and their major components were evaluated with regard to the variables: first germination count, total germination, GVI (germination velocity index, seedling dry weight and average lengths of shoots and lettuce roots. The essential oils from lemon grass and basil displayed allelopathic potentials on seed germination and vigor of lettuce achenes that can be assigned to their respective major constituents citral and eugenol. On the other hand, the allelopathic effect of the essential oil from basil was a consequence of the combined effect of all the components, regardless the application method.

  11. Seed Biofortification and Phytic Acid Reduction: A Conflict of Interest for the Plant?

    Directory of Open Access Journals (Sweden)

    Francesca Sparvoli

    2015-11-01

    Full Text Available Most of the phosphorus in seeds is accumulated in the form of phytic acid (myo-inositol-1,2,3,4,5,6-hexakisphosphate, InsP6. This molecule is a strong chelator of cations important for nutrition, such as iron, zinc, magnesium, and calcium. For this reason, InsP6 is considered an antinutritional factor. In recent years, efforts to biofortify seeds through the generation of low phytic acid (lpa mutants have been noteworthy. Moreover, genes involved in the biosynthesis and accumulation of this molecule have been isolated and characterized in different species. Beyond its role in phosphorus storage, phytic acid is a very important signaling molecule involved in different regulatory processes during plant development and responses to different stimuli. Consequently, many lpa mutants show different negative pleitotropic effects. The strength of these pleiotropic effects depends on the specific mutated gene, possible functional redundancy, the nature of the mutation, and the spatio-temporal expression of the gene. Breeding programs or transgenic approaches aimed at development of new lpa mutants must take into consideration these different aspects in order to maximize the utility of these mutants.

  12. Hydrogen storage by carbon materials synthesized from oil seeds and fibrous plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Sharon, Maheshwar; Bhardwaj, Sunil; Jaybhaye, Sandesh [Nanotechnology Research Center, Birla College, Kalyan 421304 (India); Soga, T.; Afre, Rakesh [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya (Japan); Sathiyamoorthy, D.; Dasgupta, K. [Powder Metallurgy Division, BARC, Trombay 400 085 (India); Sharon, Madhuri [Monad Nanotech Pvt. Ltd., A702 Bhawani Tower, Powai, Mumbai 400 076 (India)

    2007-12-15

    Carbon materials of various morphologies have been synthesized by pyrolysis of various oil-seeds and plant's fibrous materials. These materials are characterized by SEM and Raman. Surface areas of these materials are determined by methylene blue method. These carbon porous materials are used for hydrogen storage. Carbon fibers with channel type structure are obtained from baggas and coconut fibers. It is reported that amongst the different plant based precursors studied, carbon from soyabean (1.09 wt%) and baggas (2.05 wt%) gave the better capacity to store hydrogen at 11kg/m{sup 2} pressure of hydrogen at room temperature. Efforts are made to correlate the hydrogen adsorption capacity with intensities and peak positions of G- and D-band obtained with carbon materials synthesized from plant based precursors. It is suggested that carbon materials whose G-band is around 1575cm{sup -1} and the intensity of D-band is less compared to G-band, may be useful material for hydrogen adsorption study. (author)

  13. Roles of ABA Signal Transduction during Higher Plant Seed Development and Germination

    Institute of Scientific and Technical Information of China (English)

    Shao Hongbo; Liang Zongsuo; Shao Mingan

    2003-01-01

    ABA is one of the 5 phytohormones in higher plants, which is also the most important hormone that regulates higher plants in response to environmental stress, by ABA signal transduction. Understanding ABA signal transduction at the molecular level is crucial to biology and ecology, and rational breeding complied with corresponding eco-environmental changes.Great advancements have taken place over the past 10 years by application of the 4rabidopsis experimental system. Many components involved in ABA signal transduction have been isolated and identified and a clear overall picture of gene expression and control for this transduction has become an Accepted fact. On the basis of the work in our laboratory, in conjunction with the data available at the moment, the authors have attempted to integrate ABA signal transduction pathways into a common one and give some insights into the relationship between ABA signal transduction and other hormone signal transduction pathways, with an emphasis upon the ABA signal transduction during higher plant seed development. A future challenge in this field is that different experimental systems are applied and various receptors and genes need to be characterized through the utilization of microarray chips.

  14. Production of wax esters in plant seed oils by oleosomal cotargeting of biosynthetic enzymes[S

    Science.gov (United States)

    Heilmann, Mareike; Iven, Tim; Ahmann, Katharina; Hornung, Ellen; Stymne, Sten; Feussner, Ivo

    2012-01-01

    Wax esters are neutral lipids exhibiting desirable properties for lubrication. Natural sources have traditionally been whales. Additionally some plants produce wax esters in their seed oil. Currently there is no biological source available for long chain length monounsaturated wax esters that are most suited for industrial applications. This study aimed to identify enzymatic requirements enabling their production in oilseed plants. Wax esters are generated by the action of fatty acyl-CoA reductase (FAR), generating fatty alcohols and wax synthases (WS) that esterify fatty alcohols and acyl-CoAs to wax esters. Based on their substrate preference, a FAR and a WS from Mus musculus were selected for this study (MmFAR1 and MmWS). MmWS resides in the endoplasmic reticulum (ER), whereas MmFAR1 associates with peroxisomes. The elimination of a targeting signal and the fusion to an oil body protein yielded variants of MmFAR1 and MmWS that were cotargeted and enabled wax ester production when coexpressed in yeast or Arabidopsis. In the fae1 fad2 double mutant, rich in oleate, the cotargeted variants of MmFAR1 and MmWS enabled formation of wax esters containing >65% oleyl-oleate. The data suggest that cotargeting of unusual biosynthetic enzymes can result in functional interplay of heterologous partners in transgenic plants. PMID:22878160

  15. Caterpillar seed predators mediate shifts in selection on flowering phenology in their host plant.

    Science.gov (United States)

    Valdés, Alicia; Ehrlén, Johan

    2017-01-01

    Variation in selection among populations and years has important implications for evolutionary trajectories of populations. Yet, the agents of selection causing this variation have rarely been identified. Selection on the time of reproduction within a season in plants might differ both among populations and among years, and selection can be mediated by both mutualists and antagonists. We investigated if differences in the direction of phenotypic selection on flowering phenology among 20 populations of Gentiana pneumonanthe during 2 yr were related to the presence of the butterfly seed predator Phengaris alcon, and if butterfly incidence was associated with the abundance of the butterfly's second host, Myrmica ants. In plant populations without the butterfly, phenotypic selection favored earlier flowering. In populations where the butterfly was present, caterpillars preferentially attacked early-flowering individuals, shifting the direction of selection to favoring later flowering. Butterfly incidence in plant populations increased with ant abundance. Our results demonstrate that antagonistic interactions can shift the direction of selection on flowering phenology, and suggest that such shifts might be associated with differences in the community context.

  16. Over-expression of AtPAP2 in Camelina sativa leads to faster plant growth and higher seed yield

    Directory of Open Access Journals (Sweden)

    Zhang Youjun

    2012-04-01

    Full Text Available Abstract Background Lipids extracted from seeds of Camelina sativa have been successfully used as a reliable source of aviation biofuels. This biofuel is environmentally friendly because the drought resistance, frost tolerance and low fertilizer requirement of Camelina sativa allow it to grow on marginal lands. Improving the species growth and seed yield by genetic engineering is therefore a target for the biofuels industry. In Arabidopsis, overexpression of purple acid phosphatase 2 encoded by Arabidopsis (AtPAP2 promotes plant growth by modulating carbon metabolism. Overexpression lines bolt earlier and produce 50% more seeds per plant than wild type. In this study, we explored the effects of overexpressing AtPAP2 in Camelina sativa. Results Under controlled environmental conditions, overexpression of AtPAP2 in Camelina sativa resulted in longer hypocotyls, earlier flowering, faster growth rate, higher photosynthetic rate and stomatal conductance, increased seed yield and seed size in comparison with the wild-type line and null-lines. Similar to transgenic Arabidopsis, activity of sucrose phosphate synthase in leaves of transgenic Camelina was also significantly up-regulated. Sucrose produced in photosynthetic tissues supplies the building blocks for cellulose, starch and lipids for growth and fuel for anabolic metabolism. Changes in carbon flow and sink/source activities in transgenic lines may affect floral, architectural, and reproductive traits of plants. Conclusions Lipids extracted from the seeds of Camelina sativa have been used as a major constituent of aviation biofuels. The improved growth rate and seed yield of transgenic Camelina under controlled environmental conditions have the potential to boost oil yield on an area basis in field conditions and thus make Camelina-based biofuels more environmentally friendly and economically attractive.

  17. Extinction probabilities for a distylous plant population modeled by an inhomogeneous random walk on the positive quadrant

    CERN Document Server

    Lafitte-Godillon, Pauline; Tran, Viet Chi

    2012-01-01

    In this paper, we study a distylous flower population in which self-reproduction is not permitted. Individuals are diploid, and two alleles, A and a, can be found at the considered locus S. Pollen and ovules of flowers with the same genotype at locus S cannot mate. This prevents the pollen of a given flower to fecundate its stigmates. Only genotypes AA and Aa can be maintained in the population, so that the latter can be described by a random walk in the positive quadrant whose components are the number of individuals of each genotype. This random walk is not homogeneous and its transitions depend on the location of the process. We are interested in the computation of the extinction probabilities, where extinction happens when one of the axis is reached by the process. These extinction probabilities, which depend on the initial condition, satisfy a doubly-indexed recurrence equation that cannot be solved directly. We consider the associated generating function and show that it satisfies a partial differential...

  18. Testicular disorders induced by plant growth regulators: cellular protection with proanthocyanidins grape seeds extract.

    Science.gov (United States)

    Hassan, Hanaa A; Isa, Ahmed M; El-Kholy, Wafaa M; Nour, Samar E

    2013-10-01

    The present study aims to investigate the adverse effects of plant growth regulators : gibberellic acid (GA3) and indoleacetic acid (IAA) on testicular functions in rats, and extends to investigate the possible protective role of grape seed extract, proanthocyanidin (PAC). Male rats were divided into six groups; control group, PAC, GA3, IAA, GA3 + PAC and IAA + PAC groups. The data showed that GA3 and IAA caused significant increase in total lipids, total cholesterol, triglycerides, phospholipids and low-density-lipoprotein cholesterol in the serum, concomitant with a significant decrease in high-density-lipoprotein cholesterol, total protein, and testosterone levels. In addition, there was significant decrease in the activity of alkaline phosphatase, acid phosphatase, and gamma-glutamyl transferase. A significant decrease was detected also in epididymyal fructose along with a significant reduction in sperm count. Testicular lipid peroxidation product and hydrogen peroxide (H2O2) levels were significantly increased. Meanwhile, the total antioxidant capacity, glutathione, sulphahydryl group content, as well as superoxide dismutase, catalase, and glucose-6-phosphate dehydrogenase activity were significantly decreased. Moreover, there were a number of histopathological testicular changes including Leydig's cell degeneration, reduction in seminiferous tubule and necrotic symptoms and sperm degeneration in both GA3- and IAA-treated rats. However, an obvious recovery of all the above biochemical and histological testicular disorders was detected when PAC seed extract was supplemented to rats administered with GA3 or IAA indicating its protective effect. Therefore it was concluded that supplementation with PAC had ameliorative effects on those adverse effects of the mentioned plant growth regulators through its natural antioxidant properties.

  19. 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.

  20. Species Diversity Distribution Patterns of Chinese Endemic Seed Plants Based on Geographical Regions

    Science.gov (United States)

    Huang, Jihong; Ma, Keping; Huang, Jianhua

    2017-01-01

    Based on a great number of literatures, we established the database about the Chinese endemic seed plants and analyzed the compositions, growth form, distribution and angiosperm original families of them within three big natural areas and seven natural regions. The results indicate that the above characters of Chinese endemic plants take on relative rule at the different geographical scales. Among the three big natural areas, Eastern Monsoon area has the highest endemic plants richness, whereas Northwest Dryness area is the lowest. For life forms, herbs dominate. In contrast, the proportion of herbs of Eastern Monsoon area is remarkable under other two areas. Correspondingly the proportions of trees and shrubs are substantially higher than other two. For angiosperm original families, the number is the highest in Eastern Monsoon area, and lowest in Northwest Dryness area. On the other hand, among the seven natural regions, the humid and subtropical zone in Central and Southern China has the highest endemic plants richness, whereas the humid, hemi-humid region and temperate zone in Northeast China has the lowest. For life forms, the proportion of herbs tends to decrease from humid, hemi-humid region and temperate zone in Northeast China to humid and tropical zone in Southern China. Comparably, trees, shrubs and vines or lianas increase with the same directions. This fully represents these characters of Chinese endemic plants vary with latitudinal gradients. Furthermore, as to the number of endemic plants belonging to angiosperm original families, the number is the most in humid and subtropical zone in Center and Southern China, and tropical zone in Southern China in the next place. In contrast, the endemic plant of these two regions relatively is richer than that of The Qinghai-Tibet alpine and cold region. All above results sufficiently reflect that the Chinese endemic plants mainly distribute in Eastern Monsoon area, especially humid and subtropical zone in Center

  1. Species Diversity Distribution Patterns of Chinese Endemic Seed Plants Based on Geographical Regions.

    Science.gov (United States)

    Huang, Jihong; Ma, Keping; Huang, Jianhua

    2017-01-01

    Based on a great number of literatures, we established the database about the Chinese endemic seed plants and analyzed the compositions, growth form, distribution and angiosperm original families of them within three big natural areas and seven natural regions. The results indicate that the above characters of Chinese endemic plants take on relative rule at the different geographical scales. Among the three big natural areas, Eastern Monsoon area has the highest endemic plants richness, whereas Northwest Dryness area is the lowest. For life forms, herbs dominate. In contrast, the proportion of herbs of Eastern Monsoon area is remarkable under other two areas. Correspondingly the proportions of trees and shrubs are substantially higher than other two. For angiosperm original families, the number is the highest in Eastern Monsoon area, and lowest in Northwest Dryness area. On the other hand, among the seven natural regions, the humid and subtropical zone in Central and Southern China has the highest endemic plants richness, whereas the humid, hemi-humid region and temperate zone in Northeast China has the lowest. For life forms, the proportion of herbs tends to decrease from humid, hemi-humid region and temperate zone in Northeast China to humid and tropical zone in Southern China. Comparably, trees, shrubs and vines or lianas increase with the same directions. This fully represents these characters of Chinese endemic plants vary with latitudinal gradients. Furthermore, as to the number of endemic plants belonging to angiosperm original families, the number is the most in humid and subtropical zone in Center and Southern China, and tropical zone in Southern China in the next place. In contrast, the endemic plant of these two regions relatively is richer than that of The Qinghai-Tibet alpine and cold region. All above results sufficiently reflect that the Chinese endemic plants mainly distribute in Eastern Monsoon area, especially humid and subtropical zone in Center

  2. Selenium hyperaccumulator plants Stanleya pinnata and Astragalus bisulcatus are colonized by Se-resistant, Se-excluding wasp and beetle seed herbivores.

    Science.gov (United States)

    Freeman, John L; Marcus, Matthew A; Fakra, Sirine C; Devonshire, Jean; McGrath, Steve P; Quinn, Colin F; Pilon-Smits, Elizabeth A H

    2012-01-01

    Selenium (Se) hyperaccumulator plants can concentrate the toxic element Se up to 1% of shoot (DW) which is known to protect hyperaccumulator plants from generalist herbivores. There is evidence for Se-resistant insect herbivores capable of feeding upon hyperaccumulators. In this study, resistance to Se was investigated in seed chalcids and seed beetles found consuming seeds inside pods of Se-hyperaccumulator species Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were determined in seeds collected from hyperaccumulators in a seleniferous habitat and in seed herbivores. Astragalus bisulcatus seeds were consumed by seed beetle larvae (Acanthoscelides fraterculus Horn, Coleoptera: Bruchidae) and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae). Stanleya pinnata seeds were consumed by an unidentified seed chalcid larva. Micro X-ray absorption near-edge structure (µXANES) and micro-X-Ray Fluorescence mapping (µXRF) demonstrated Se was mostly organic C-Se-C forms in seeds of both hyperaccumulators, and S. pinnata seeds contained ∼24% elemental Se. Liquid chromatography-mass spectrometry of Se-compounds in S. pinnata seeds detected the C-Se-C compound seleno-cystathionine while previous studies of A. bisulcatus seeds detected the C-Se-C compounds methyl-selenocysteine and γ-glutamyl-methyl-selenocysteine. Micro-XRF and µXANES revealed Se ingested from hyperaccumulator seeds redistributed throughout seed herbivore tissues, and portions of seed C-Se-C were biotransformed into selenocysteine, selenocystine, selenodiglutathione, selenate and selenite. Astragalus bisulcatus seeds contained on average 5,750 µg Se g(-1), however adult beetles and adult chalcid wasps emerging from A. bisulcatus seed pods contained 4-6 µg Se g(-1). Stanleya pinnata seeds contained 1,329 µg Se g(-1) on average; however chalcid wasp larvae and adults emerging from S. pinnata seed pods contained 9 and 47 µg Se g(-1). The

  3. Selenium hyperaccumulator plants Stanleya pinnata and Astragalus bisulcatus are colonized by Se-resistant, Se-excluding wasp and beetle seed herbivores.

    Directory of Open Access Journals (Sweden)

    John L Freeman

    Full Text Available Selenium (Se hyperaccumulator plants can concentrate the toxic element Se up to 1% of shoot (DW which is known to protect hyperaccumulator plants from generalist herbivores. There is evidence for Se-resistant insect herbivores capable of feeding upon hyperaccumulators. In this study, resistance to Se was investigated in seed chalcids and seed beetles found consuming seeds inside pods of Se-hyperaccumulator species Astragalus bisulcatus and Stanleya pinnata. Selenium accumulation, localization and speciation were determined in seeds collected from hyperaccumulators in a seleniferous habitat and in seed herbivores. Astragalus bisulcatus seeds were consumed by seed beetle larvae (Acanthoscelides fraterculus Horn, Coleoptera: Bruchidae and seed chalcid larvae (Bruchophagus mexicanus, Hymenoptera: Eurytomidae. Stanleya pinnata seeds were consumed by an unidentified seed chalcid larva. Micro X-ray absorption near-edge structure (µXANES and micro-X-Ray Fluorescence mapping (µXRF demonstrated Se was mostly organic C-Se-C forms in seeds of both hyperaccumulators, and S. pinnata seeds contained ∼24% elemental Se. Liquid chromatography-mass spectrometry of Se-compounds in S. pinnata seeds detected the C-Se-C compound seleno-cystathionine while previous studies of A. bisulcatus seeds detected the C-Se-C compounds methyl-selenocysteine and γ-glutamyl-methyl-selenocysteine. Micro-XRF and µXANES revealed Se ingested from hyperaccumulator seeds redistributed throughout seed herbivore tissues, and portions of seed C-Se-C were biotransformed into selenocysteine, selenocystine, selenodiglutathione, selenate and selenite. Astragalus bisulcatus seeds contained on average 5,750 µg Se g(-1, however adult beetles and adult chalcid wasps emerging from A. bisulcatus seed pods contained 4-6 µg Se g(-1. Stanleya pinnata seeds contained 1,329 µg Se g(-1 on average; however chalcid wasp larvae and adults emerging from S. pinnata seed pods contained 9 and 47 µg Se g

  4. Interactions between a pollinating seed predator and its host plant: the role of environmental context within a population

    Science.gov (United States)

    Kula, Abigail A R; Castillo, Dean M; Dudash, Michele R; Fenster, Charles B

    2014-01-01

    Plant–insect interactions often are important for plant reproduction, but the outcome of these interactions may vary with environmental context. Pollinating seed predators have positive and negative effects on host plant reproduction, and the interaction outcome is predicted to vary with density or abundance of the partners. We studied the interaction between Silene stellata, an herbaceous perennial, and Hadena ectypa, its specialized pollinating seed predator. Silene stellata is only facultatively dependent upon H. ectypa for pollination because other nocturnal moth co-pollinators are equally effective at pollen transfer. We hypothesized that for plants without conspecific neighbors, H. ectypa would have higher visitation rates compared to co-pollinators, and the plants would experience lower levels of H. ectypa pollen deposition. We predicted similar oviposition throughout the study site but greater H. ectypa predation in the area without conspecific neighbors compared to plants embedded in a naturally high density area. We found that H. ectypa had consistently higher visitation than moth co-pollinators in all host plant contexts. However, H. ectypa pollinator importance declined in areas with low conspecific density because of reduced pollen deposition, resulting in lower seed set. Conversely, oviposition was similar across the study site independent of host plant density. Greater likelihood of very high fruit predation combined with lower pollination by H. ectypa resulted in reduced S. stellata female reproductive success in areas with low conspecific density. Our results demonstrate local context dependency of the outcomes of pollinating seed predator interactions with conspecific host plant density within a population. PMID:25165527

  5. Effect of Genotypes and Seed Production Environments on Seed ...

    African Journals Online (AJOL)

    Key words: Genotypes. plant popUlation, seed production. seed quality. sesame. ..... (68%). Greater standard gennination and EWSG occurred in seed produced in 2001 .... Table 7: Heritability (H2B) and genetic advance (GA) of seed quality ...

  6. 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

    2002-01-01

    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 f

  7. Planting date and seeding rate effects on sunn hemp biomass and nitrogen production for a winter cover crop

    Science.gov (United States)

    Sunn hemp (Crotalaria juncea L.) is a tropical legume that produces plant biomass and nitrogen (N) quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a subsequent rye (Secale cereale L.) wi...

  8. Ecological and evolutionary conditions for fruit abortion to regulate pollinating seed-eaters and increase plant production

    Science.gov (United States)

    Holland, J. Nathaniel; DeAngelis, Donald L.

    2002-01-01

    Coevolved mutualisms, such as those between senita cacti, yuccas, and their respective obligate pollinators, benefit both species involved in the interaction. However, in these pollination mutualisms the pollinator's larvae impose a cost on plants through consumption of developing seeds and fruit. The effects of pollinators on benefits and costs are expected to vary with the abundance of pollinators, because large population sizes result in more eggs and larval seed-eaters. Here, we develop the hypothesis that fruit abortion, which is common in yucca, senita, and plants in general, could in some cases have the function of limiting pollinator abundance and, thereby, increasing fruit production. Using a general steady-state model of fruit production and pollinator dynamics, we demonstrate that plants involved in pollinating seed-eater mutualisms can increase their fecundity by randomly aborting fruit. We show that the ecological conditions under which fruit abortion can improve plants fecundity are not unusual. They are best met when the plant is long-lived, the population dynamics of the pollinator are much faster than those of the plant, the loss of one fruit via abortion kills a larva that would have the expectation of destroying more than one fruit through its future egg laying as an adult moth, and the effects of fruit abortion on pollinator abundance are spatially localized. We then use the approach of adaptive dynamics to find conditions under which a fruit abortion strategy based on regulating the pollinator population could feasibly evolve in this type of plant–pollinator interaction.

  9. Seeds with high molybdenum concentration improved growth and nitrogen acquisition of rhizobium-inoculated and nitrogen-fertilized common bean plants

    Directory of Open Access Journals (Sweden)

    Fernanda Fátima Delgado Almeida

    2013-04-01

    Full Text Available Seeds of common bean (Phaseolus vulgaris with high molybdenum (Mo concentration can supply Mo plant demands, but to date no studies have concomitantly evaluated the effects of Mo-enriched seeds on plants inoculated with rhizobia or treated with N fertilizer. This work evaluated the effects of seed Mo on growth and N acquisition of bean plants fertilized either by symbiotic N or mineral N, by measuring the activities of nitrogenase and nitrate reductase and the contribution of biological N2 fixation at different growth stages. Seeds enriched or not with Mo were sown with two N sources (inoculated with rhizobia or fertilized with N, in pots with 10 kg of soil. In experiment 1, an additional treatment consisted of Mo-enriched seeds with Mo applied to the soil. In experiment 2, the contribution of N2 fixation was estimated by 15N isotope dilution. Common bean plants grown from seeds with high Mo concentration flowered one day earlier. Seeds with high Mo concentration increased the leaf area, shoot mass and N accumulation, with both N sources. The absence of effects of Mo application to the soil indicated that Mo contents of Mo-enriched seeds were sufficient for plant growth. Seeds enriched with Mo increased nitrogenase activity at the vegetative stage of inoculated plants, and nitrate reductase activity at late growth stages with both N sources. The contribution of N2 fixation was 17 and 61 % in plants originating from low- or high-Mo seeds, respectively. The results demonstrate the benefits of sowing Mo-enriched seeds on growth and N nutrition of bean plants inoculated with rhizobia or fertilized with mineral N fertilizer.

  10. Altered starch turnover in the maternal plant has major effects on Arabidopsis fruit growth and seed composition.

    Science.gov (United States)

    Andriotis, Vasilios M E; Pike, Marilyn J; Schwarz, Sabine L; Rawsthorne, Stephen; Wang, Trevor L; Smith, Alison M

    2012-11-01

    Mature seeds of both the high-starch starch-excess1 (sex1) mutant and the almost starchless phosphoglucomutase1 mutant of Arabidopsis (Arabidopsis thaliana) have 30% to 40% less lipid than seeds of wild-type plants. We show that this is a maternal effect and is not attributable to the defects in starch metabolism in the embryo itself. Low lipid contents and consequent slow postgerminative growth are seen only in mutant embryos that develop on maternal plants with mutant phenotypes. Mutant embryos that develop on plants with wild-type starch metabolism have wild-type lipid contents and postgerminative growth. The maternal effect on seed lipid content is attributable to carbohydrate starvation in the mutant fruit at night. Fruits on sex1 plants grow more slowly than those on wild-type plants, particularly at night, and have low sugars and elevated expression of starvation genes at night. Transcript levels of the transcription factor WRINKLED1, implicated in lipid synthesis, are reduced at night in sex1 but not in wild-type seeds, and so are transcript levels of key enzymes of glycolysis and fatty acid synthesis. sex1 embryos develop more slowly than wild-type embryos. We conclude that the reduced capacity of mutant plants to convert starch to sugars in leaves at night results in low nighttime carbohydrate availability in the developing fruit. This in turn reduces the rate of development and expression of genes encoding enzymes of storage product accumulation in the embryo. Thus, the supply of carbohydrate from the maternal plant to the developing fruit at night can have an important influence on oilseed composition and on postgerminative growth.

  11. Estimating seed and pollen movement in a monoecious plant: a hierarchical Bayesian approach integrating genetic and ecological data.

    Science.gov (United States)

    Moran, Emily V; Clark, James S

    2011-03-01

    The scale of seed and pollen movement in plants has a critical influence on population dynamics and interspecific interactions, as well as on their capacity to respond to environmental change through migration or local adaptation. However, dispersal can be challenging to quantify. Here, we present a Bayesian model that integrates genetic and ecological data to simultaneously estimate effective seed and pollen dispersal parameters and the parentage of sampled seedlings. This model is the first developed for monoecious plants that accounts for genotyping error and treats dispersal from within and beyond a plot in a fully consistent manner. The flexible Bayesian framework allows the incorporation of a variety of ecological variables, including individual variation in seed production, as well as multiple sources of uncertainty. We illustrate the method using data from a mixed population of red oak (Quercus rubra, Q. velutina, Q. falcata) in the NC piedmont. For simulated test data sets, the model successfully recovered the simulated dispersal parameters and pedigrees. Pollen dispersal in the example population was extensive, with an average father-mother distance of 178 m. Estimated seed dispersal distances at the piedmont site were substantially longer than previous estimates based on seed-trap data (average 128 m vs. 9.3 m), suggesting that, under some circumstances, oaks may be less dispersal-limited than is commonly thought, with a greater potential for range shifts in response to climate change.

  12. Seed Germination in Chenopodium album L: Relationships between Nitrate and the Effects of Plant Hormones.

    Science.gov (United States)

    Saini, H S; Bassi, P K; Spencer, M S

    1985-04-01

    Effects of ethylene, gibberellins, and kinetin on the germination of two lots of Chenopodium album L. seeds, collected from the field in 1982 and 1983, were studied in relation to the availability of nitrate. The experiments were conducted in darkness and at temperatures ranging from 12 to 32 degrees C. Ethylene induced over 75% germination in the 1983 seed but had little effect on the 1982 seed. Nitrate was only slightly promotive in either of the two seed lots. A combination of ethylene and nitrate, however, acted synergistically on 1982 seed, resulting in as much germination as that induced in 1983 seed by ethylene alone. In 1983 seed, a combination of ethylene and nitrate was only marginally more effective than ethylene. A similar relationship was observed in the effects of gibberellic acid(4+7) (GA(4+7)) and nitrate on seeds from the two lots. The 1982 seed, which responded synergistically to combinations of nitrate with ethylene or GA(4+7) was found to contain an extremely low endogenous level of nitrate as compared to 1983 seed. Thus, high levels of either endogenous or applied nitrate appeared to enhance the germination response to ethylene or GA(4+7).Kinetin had no effect on 1982 seed and only a small promotive effect on 1983 seed. There was no synergism between kinetin and nitrate in either of the seed lots.

  13. Germination Ecology and Seed Dispersal of a Critically Endangered Plant: A Case Study of Pomaderris vacciniifolia (Round-Leaf Pomaderris).

    Science.gov (United States)

    Patykowski, John; Dell, Matthew; Gibson, Maria

    2016-01-01

    Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia-a critically endangered, rare endemic Australian shrub-were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world.

  14. Preliminary studies on allelopatic effect of some woody plants on seed germination of rye-grass and tall fescue.

    Science.gov (United States)

    Arouiee, H; Nazdar, T; Mousavi, A

    2010-11-01

    In order to investigation of allelopathic effects of some ornamental trees on seed germination of rye-grass (Lolium prenne) and tall fescue (Festuca arundinaceae), this experiment was conducted in a randomized complete block design with 3 replicates at the laboratory of Horticultural Sciences Department of Ferdowsi University of Mashhad, during 2008. In this research, we studied the effect of aqueous and hydro-alcoholic extracts of Afghanistan pine (Pinus eldarica), arizona cypress (Cupressus arizonica), black locust (Robinia psedue acacia) and box elder (Acer negundo) leaves that prepared in 1:5 ratio on seed germination percent and rate for two grasses. The results showed that all extracts decreased statistically seed germination in compared to control treatment. The highest germination percentage and germination rate of tested grass detected in control treatment. Hydro-alcoholic extracts of all woody plants (15, 30%) were completely inhibited seed germination of rye-grass and tall fescue. Also aqueous extract of arizona cypress was completely inhibited seed germination of tall fescue and had more inhibitory activity than other aqueous extracts on rye-grass. Between aqueous extracts, the highest and lowest seed germination of rye-grass was found in Afghanistan pine and arizona cypress, respectively.

  15. Light and Plants. A Series of Experiments Demonstrating Light Effects on Seed Germination, Plant Growth, and Plant Development.

    Science.gov (United States)

    Downs, R. J.; And Others

    A brief summary of the effects of light on plant germination, growth and development, including photoperiodism and pigment formation, introduces 18 experiments and demonstrations which illustrate aspects of these effects. Detailed procedures for each exercise are given, the expected results outlined, and possible sources of difficulty discussed.…

  16. Ecological and genetic factors linked to contrasting genome dynamics in seed plants.

    Science.gov (United States)

    Leitch, A R; Leitch, I J

    2012-05-01

    The large-scale replacement of gymnosperms by angiosperms in many ecological niches over time and the huge disparity in species numbers have led scientists to explore factors (e.g. polyploidy, developmental systems, floral evolution) that may have contributed to the astonishing rise of angiosperm diversity. Here, we explore genomic and ecological factors influencing seed plant genomes. This is timely given the recent surge in genomic data. We compare and contrast the genomic structure and evolution of angiosperms and gymnosperms and find that angiosperm genomes are more dynamic and diverse, particularly amongst the herbaceous species. Gymnosperms typically have reduced frequencies of a number of processes (e.g. polyploidy) that have shaped the genomes of other vascular plants and have alternative mechanisms to suppress genome dynamism (e.g. epigenetics and activity of transposable elements). Furthermore, the presence of several characters in angiosperms (e.g. herbaceous habit, short minimum generation time) has enabled them to exploit new niches and to be viable with small population sizes, where the power of genetic drift can outweigh that of selection. Together these processes have led to increased rates of genetic divergence and faster fixation times of variation in many angiosperms compared with gymnosperms.

  17. A novel chitin-binding protein from Moringa oleifera seed with potential for plant disease control.

    Science.gov (United States)

    Gifoni, Juliana M; Oliveira, José T A; Oliveira, Hermogenes D; Batista, Adelina B; Pereira, Mirella L; Gomes, Antoniella S; Oliveira, Henrique P; Grangeiro, Thalles B; Vasconcelos, Ilka M

    2012-01-01

    A thermostable chitin-binding protein (14.3 kDa) with antifungal activity was isolated from Moringa oleifera seeds by affinity chromatography on chitin followed by ion exchange chromatography. NH(2-) CPAIQRCCQQLRNIQPPCRCCQ (Mo-CBP3) is a glycoprotein with 2.5% sugar, pI 10.8, without hemagglutination, chitinase or beta-glucanase activities. Mo-CBP3 possesses in vitro antifungal activity against the phytopathogenicfungi Fusarium solani, F. oxysporum, Colletotrichum musae and C. gloesporioides. Contrarily, Mo-CBP3 did not affect Pythium oligandrum, an oomycete. At 0.05 mg/ml, Mo-CBP3 showed to be fungistatic against F. solani, but at 0.1 mg/ml Mo-CBP3 behaved as a potent fungicidal agent as it inhibited both the spore germination and mycelial growth of F. solani. Surprisingly, the effect of Mo-CBP3 against spore germination was observed even when the protein was heated at 100 degrees C for 1 h or pretreated with 0.15M N-acetyl-D-glucosamine. Mo-CBP3 inhibited the glucose-stimulated acidification of the incubation medium by F. solani. This is apparently caused by structural plasma membrane disarrangement induced by Mo-CBP3. Altogether, these results suggest that Mo-CBP3 might be involved in plant defense mechanisms and could be used as potential antifungal agent for controlling fungal pathogens in plants.

  18. Seed yield and quality of pepper plants grown under salt stress

    African Journals Online (AJOL)

    İbrahim Demir

    2013-12-04

    Dec 4, 2013 ... African Journal of Biotechnology. Full Length Research Paper. Seed yield and ... Key words: Pepper, fruit yield, seed quality, salinity. INTRODUCTION .... Salt injury symptoms, such as chlorosis, burning leaves, and necrotic ...

  19. Seed germination and in vitro regeneration of the African medicinal and pesticidal plant, Bobgunnia madagascariensis

    OpenAIRE

    Thokozani, Blackson L.K.; Zulu, Donald; Gudeta W. Sileshi; Teklehaimanot, Zewge; Gondwe, Dominic S.B.; Sarasan, Viswambharan; Stevenson, Philip

    2011-01-01

    Propagation of the medicinal and pesticidal tree, Bobgunnia madagascarensis is difficult due to poor and erratic germination of its seeds and slow growth of its seedlings. This study involved two separate experiments. The first evaluated the effect of pre-sowing treatments and growing medium on ex vitro seed germination and early seedling development. The second experiment involved in vitro germination, shoot initiation and rooting of shoots. Pre-sowing seed treatments involved soaking seeds ...

  20. Seed plant phylogeny inferred from all three plant genomes: monophyly of extant gymnosperms and origin of Gnetales from conifers.

    Science.gov (United States)

    Chaw, S M; Parkinson, C L; Cheng, Y; Vincent, T M; Palmer, J D

    2000-04-11

    Phylogenetic relationships among the five groups of extant seed plants are presently quite unclear. For example, morphological studies consistently identify the Gnetales as the extant sister group to angiosperms (the so-called "anthophyte" hypothesis), whereas a number of molecular studies recover gymnosperm monophyly, and few agree with the morphology-based placement of Gnetales. To better resolve these and other unsettled issues, we have generated a new molecular data set of mitochondrial small subunit rRNA sequences, and have analyzed these data together with comparable data sets for the nuclear small subunit rRNA gene and the chloroplast rbcL gene. All nuclear analyses strongly ally Gnetales with a monophyletic conifers, whereas all mitochondrial analyses and those chloroplast analyses that take into account saturation of third-codon position transitions actually place Gnetales within conifers, as the sister group to the Pinaceae. Combined analyses of all three genes strongly support this latter relationship, which to our knowledge has never been suggested before. The combined analyses also strongly support monophyly of extant gymnosperms, with cycads identified as the basal-most group of gymnosperms, Ginkgo as the next basal, and all conifers except for Pinaceae as sister to the Gnetales + Pinaceae clade. According to these findings, the Gnetales may be viewed as extremely divergent conifers, and the many morphological similarities between angiosperms and Gnetales (e.g., double fertilization and flower-like reproductive structures) arose independently.

  1. Anti-hyperglycaemic globulins from selected Cucurbitaceae seeds used as antidiabetic medicinal plants in Africa

    Science.gov (United States)

    2013-01-01

    Background The recent epidemic of diabetes mellitus (DM) in Africa, coupled with rampant poverty, is an indication of the urgent need to develop new efficacious, cheaper and more available drugs to face this growing public health challenge. A number of plants products among which the protein-rich Cucurbitaceae seeds are commonly used in traditional medicine with increasing acclaimed efficacy against DM. The aim of this study was to analyse and evaluate the hypoglycaemic activity of storage proteins of five species of Cucurbitaceae, which include Telfairia occidentalis, Citrullus lanatus, Lagenaria siceraria, Cucumeropsis mannii and Cucurbita moschata. Methods The different families of storage proteins were extracted following differential solubility, and their contents were estimated using the Bradford method. The analysis of these proteins was done by electrophoresis in non-denaturing and denaturing conditions. The evaluation of hypoglycaemic properties of various globulins extracted was performed on male Wistar rats by the oral glucose tolerance test. Results The results showed that among the proteins extracted, globulins constitute the most abundant class of storage proteins in all five species selected. Citrullus lanatus and Cucurbita moschata presented the highest levels of globulin (275.34 and 295.11 mg/g dry matter, respectively). The results of electrophoresis showed that all species possess acidic and neutrals albumins and globulins, with molecular weight of protein subunits ranging from 6.36-44.11 kDa for albumins, 6.5-173.86 kDa for globulins and 6.5-49.66 kDa for glutelins. The 6.36 kDa of albumin subunit protein and the 6.5 kDa of globulin subunit protein were present in all the species. The oral glucose tolerance test showed that the globulins of the seeds of all species except Cucumeropsis mannii caused significant drop in blood sugar (88 – 137.80%, compared to the controls, p<0.05). Conclusions These findings showed that the selected Cucurbitaceae

  2. The seed plant flora of the Mount Jinggangshan region, southeastern China.

    Science.gov (United States)

    Wang, Lei; Liao, Wenbo; Chen, Chunquan; Fan, Qiang

    2013-01-01

    The Mount Jinggangshan region is located between Jiangxi and Hunan provinces in southeastern China in the central section of the Luoxiao Mountains. A detailed investigation of Mount Jinggangshan region shows that the seed plant flora comprises 2,958 species in 1,003 genera and 210 families (Engler's system adjusted according to Zhengyi Wu's concept). Among them, 23 species of gymnospermae belong to 17 genera and 9 families, and 2,935 species of angiosperms are in 986 genera and 201 families. Moreover, they can also be sorted into woody plants (350 genera and 1,295 species) and herbaceous plants (653 genera and 1,663 species). The dominant families are mainly Fagaceae, Lauraceae, Theaceae, Hamamelidaceae, Magnoliaceae, Ericaceae, Styracaceae, Aquifoliaceae, Elaeocarpaceae, Aceraceae, Rosaceae, Corylaceae, Daphniphyllaceae, Symplocaceae, Euphorbiaceae, Pinaceae, Taxodiaceae, Cupressaceae and Taxaceae. Ancient and relic taxa include Ginkgo biloba, Fokieniahodginsii, Amentotaxusargotaenia, Disanthuscercidifolia subsp. longipes, Hamamelismollis, Manglietiafordiana, Magnoliaofficinalis, Tsoongiodendronodorum, Fortuneariasinensis, Cyclocaryapaliurus, Eucommiaulmoides, Sargentodoxacuneata, Bretschneiderasinensis, Camptothecaacuminata, Tapisciasinensis, etc. The flora of Mount Jinggangshan region includes 79 cosmopolitan genera and 924 non-cosmopolitan genera, which are 7.88% and 92.12% of all genera. The latter includes 452 tropical genera (48.92%) and 472 temperate genera (51.08%). The temperate elements include 44 genera endemic to China, accounting for 4.76% of all genera. Among 1,003 genera, 465 have only a single species and 401 are oligotypic genera (with 2-5 species). These genera account for 86.34% of all genera. The floristic analysis indicates that the flora of Mount Jinggangshan region is closely related to the flora of Mount Wuyishan region in southeastern China. The flora of Mount Jinggangshan region also contains many elements of central and southern China

  3. The seed plant flora of the Mount Jinggangshan region, southeastern China.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available The Mount Jinggangshan region is located between Jiangxi and Hunan provinces in southeastern China in the central section of the Luoxiao Mountains. A detailed investigation of Mount Jinggangshan region shows that the seed plant flora comprises 2,958 species in 1,003 genera and 210 families (Engler's system adjusted according to Zhengyi Wu's concept. Among them, 23 species of gymnospermae belong to 17 genera and 9 families, and 2,935 species of angiosperms are in 986 genera and 201 families. Moreover, they can also be sorted into woody plants (350 genera and 1,295 species and herbaceous plants (653 genera and 1,663 species. The dominant families are mainly Fagaceae, Lauraceae, Theaceae, Hamamelidaceae, Magnoliaceae, Ericaceae, Styracaceae, Aquifoliaceae, Elaeocarpaceae, Aceraceae, Rosaceae, Corylaceae, Daphniphyllaceae, Symplocaceae, Euphorbiaceae, Pinaceae, Taxodiaceae, Cupressaceae and Taxaceae. Ancient and relic taxa include Ginkgo biloba, Fokieniahodginsii, Amentotaxusargotaenia, Disanthuscercidifolia subsp. longipes, Hamamelismollis, Manglietiafordiana, Magnoliaofficinalis, Tsoongiodendronodorum, Fortuneariasinensis, Cyclocaryapaliurus, Eucommiaulmoides, Sargentodoxacuneata, Bretschneiderasinensis, Camptothecaacuminata, Tapisciasinensis, etc. The flora of Mount Jinggangshan region includes 79 cosmopolitan genera and 924 non-cosmopolitan genera, which are 7.88% and 92.12% of all genera. The latter includes 452 tropical genera (48.92% and 472 temperate genera (51.08%. The temperate elements include 44 genera endemic to China, accounting for 4.76% of all genera. Among 1,003 genera, 465 have only a single species and 401 are oligotypic genera (with 2-5 species. These genera account for 86.34% of all genera. The floristic analysis indicates that the flora of Mount Jinggangshan region is closely related to the flora of Mount Wuyishan region in southeastern China. The flora of Mount Jinggangshan region also contains many elements of central and

  4. Effective selenium detoxification in the seed proteins of a hyperaccumulator plant: the analysis of selenium-containing proteins of monkeypot nut (Lecythis minor) seeds.

    Science.gov (United States)

    Németh, Anikó; Dernovics, Mihály

    2015-01-01

    A shotgun proteomic approach was applied to characterize the selenium (Se)-containing proteins of the selenium hyperaccumulator monkeypot nut (Lecythis minor) seeds. The exceptionally high Se content (>4,000 mg kg(-1)) of the sample enabled a straightforward procedure without the need for multiple preconcentration and fractionation steps. The proteins identified were sulfur-rich seed proteins, namely, 11S globulin (Q84ND2), 2S albumin (B6EU54), 2S sulfur-rich seed storage proteins (P04403 and P0C8Y8) and a 11S globulin-like protein (A0EM48). Database directed search for theoretically selenium-containing peptides was assisted by manual spectra evaluation to achieve around 25% coverage on sulfur analogues. Remarkable detoxification mechanisms on the proteome level were revealed in the form of multiple selenomethionine-methionine substitution and the lack of selenocysteine residues. The degree of selenomethionine substitution could be characterized by an exponential function that implies the inhibition of protein elongation by selenomethionine. Our results contribute to the deeper understanding of selenium detoxification procedures in hyperaccumulator plants.

  5. The Sixth Great Mass Extinction

    Science.gov (United States)

    Wagler, Ron

    2012-01-01

    Five past great mass extinctions have occurred during Earth's history. Humanity is currently in the midst of a sixth, human-induced great mass extinction of plant and animal life (e.g., Alroy 2008; Jackson 2008; Lewis 2006; McDaniel and Borton 2002; Rockstrom et al. 2009; Rohr et al. 2008; Steffen, Crutzen, and McNeill 2007; Thomas et al. 2004;…

  6. Organic matrix based slow release fertilizer enhances plant growth, nitrate assimilation and seed yield of Indian mustard (Brassica juncea L.).

    Science.gov (United States)

    Sharma, Vinod K; Singh, Rana P

    2011-09-01

    Field experiments were conducted to study the effect of organic matrix based slow release fertilizers (SRFs) on plant growth, nitrate assimilation and seed yield of Brassica juncea L. cv, pusa bold. The agro-waste materials like cow dung, clay soil, neem leaves and rice bran were mixed together in 2:2:1:1 ratio and used as organic matrix for the immobilization of chemical fertilizer nutrients with commercial grade saresh (Acacia gum, 15% solution) as binder. Different fertilizer treatments were organic matrix based slow release fertilizers, SRF-I (542.0 kg ha(-1)); SRF-II (736.5 kg ha(-1)) and chemical fertilizer combinations, boron (3 kg ha(-1))+sulphur (15 kg ha(-1))+nitrogen (80 kg ha(-1)) and boron (3 kg ha(-1)) + sulphur (15 kg ha(-1))+nitrogen (80 kg ha(-1))+phosphorus (15 kg ha(-1))+potassium (100 kg ha(-1)). Organic matrix based SRF-II released ammonium up to 50-d in wetsoil under laboratory conditions which showed maximum retention of the nutrients. Avery significant increase in plant growth, nitrate assimilation and seed yield was recorded in organic matrix based SRF-II applied plants. The maximum percent increase in biomass production was observed with organic matrix based SRF-II (increase of 65.8% in root fresh weight, 38.0% in root dry weight, 45.9% in leaf fresh weight plant(-1) and 27.5 % in leaf dry weight plant(-1) in 60-d old plants). It also increased the acquisition and assimilation of nitrate from the plant's rhizosphere which was evident by 45.6% increase in nitrate, 27.5% in nitrite and 11.7% in nitrate reductase activity (NRA) in leaves of 45-d old plants over control. The organic matrix based SRF-II significantly increased the seed yield by 28% in Indian mustard. Cost analysis revealed thatthis formulation is cost effective as it is based on agro waste materials.

  7. The MADS-domain protein MPF1 of Physalis floridana controls plant architecture, seed development and flowering time.

    Science.gov (United States)

    He, Chaoying; Tian, Ying; Saedler, Rainer; Efremova, Nadia; Riss, Simone; Khan, Muhammad Ramzan; Yephremov, Alexander; Saedler, Heinz

    2010-02-01

    Floral and vegetative development of plants is dependent on the combinatorial action of MADS-domain transcription factors. Members of the STMADS11 subclade, such as MPF1 of Physalis, are abundantly expressed in leaves as well as in floral organs, but their function is not yet clear. Our studies with transgenic Arabidopsis that over-express MPF1 suggest that MPF1 interacts with SOC1 to determine flowering time. However, MPF1 RNAi-mediated knockdown Physalis plants revealed a complex phenotype with changes in flowering time, plant architecture and seed size. Flowering of these plants was delayed by about 20% as compared to wild type. Expression of PFLFY is upregulated in the MPF1 RNAi lines, while PFFT and MPF3 genes are strongly repressed. MPF1 interacts with a subset of MADS-domain factors, namely with PFSOC1 in planta, and with PFSEP3 and PFFUL in yeast, supporting a regulatory role for this protein in flowering. The average size of seeds produced by the transgenic MPF1 RNAi plants is increased almost twofold. The height of these plants is also increased about twofold, but most axillary buds are stunted when compared to controls. Taken together, this suggests that members of the STMADS11 subclade act as positive regulators of flowering but have diverse functions in plant growth.

  8. Three cycles of water deficit from seed to young plants of Moringa oleifera woody species improves stress tolerance.

    Science.gov (United States)

    Rivas, Rebeca; Oliveira, Marciel T; Santos, Mauro G

    2013-02-01

    The main objective of this study was to assess whether recurring water stress occurring from seed germination to young plants of Moringa oleifera Lam. are able to mitigate the drought stress effects. Germination, gas exchange and biochemical parameters were analysed after three cycles of water deficit. Young plants were used 50 days after germination under three osmotic potentials (0.0, -0.3 and -0.4 MPa). For each germination treatment, control (irrigated) and stressed (10% of water control) plants were compared for a total of six treatments. There were two cycles of drought interspersed with 10 days of rehydration. The young plants of M. oleifera showed increased tolerance to repeated cycles of drought, maintaining high relative water content (RWC), high water use efficiency (WUE), increased photosynthetic pigments and increased activity of antioxidant enzymes. There was rapid recovery of the photosynthetic rate during the rehydration period. The stressed plants from the -0.3 and -0.4 MPa treatments showed higher tolerance compared to the control plants. The results suggest that seeds of M. oleifera subjected to mild water deficit have had increased the ability for drought tolerance when young plant.

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

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    Sunil Kumar Singh

    2013-12-01

    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 11113AS 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

  10. Infection Courts in Watermelon Plants Leading to Seed Infestation by Fusarium oxysporum f. sp. niveum.

    Science.gov (United States)

    Petkar, Aparna; Ji, Pingsheng

    2017-07-01

    Fusarium wilt incited by Fusarium oxysporum f. sp. niveum is a seed-transmitted disease that causes significant yield loss in watermelon production. The pathogen may infect watermelon seeds latently, which can be an important inoculum source and contribute to severe disease outbreak. However, information regarding infection courts of F. oxysporum f. sp. niveum leading to infestation of watermelon seeds is limited. To determine how seeds in watermelon fruit can be infested by F. oxysporum f. sp. niveum during the watermelon growing season, greenhouse and field experiments were conducted in 2014 and 2015 where watermelon flowers and immature fruit were inoculated with F. oxysporum f. sp. niveum. Seeds were extracted from mature watermelon fruit, and infestation of watermelon seeds was determined by isolation of F. oxysporum f. sp. niveum and further confirmed by real-time polymerase chain reaction (PCR) analysis. Inoculation of the pericarp of immature fruit resulted in 17.8 to 54.4% of infested seeds under field conditions and 0.6 to 12.8% of infested seeds under greenhouse conditions when seeds were not surface disinfested prior to isolation. Seed infestation was also detected in 0 to 4.5% of the seeds when seeds were surface disinfested prior to isolation. Inoculation of pistil resulted in 0 to 7.2% and 0 to 18.3% of infested seeds under greenhouse and field conditions when seeds were surface disinfested or not disinfested before isolation, respectively. Inoculation of peduncle resulted in 0.6 to 6.1% and 0 to 10.0% of infested seeds in the greenhouse and field experiments when seeds were surface disinfested or not disinfested before isolation, respectively. Seed infestation was also detected in all the experiments using real-time PCR assay when pericarp or pistil was inoculated, and in three of four experiments when peduncle was inoculated, regardless of whether seeds were surface disinfested or not disinfested. Pericarp and peduncle of immature watermelon fruit

  11. Allelopathic effects of extracts from Solidago canadensis L.against seed germination and seedling growth of some plants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    To investigate the potential role of allelopathy in plant interference and in the successful invasion of alien species Solidago canadensis, aqueous and ethanolic extracts from rhizomes, stems and leaves of S. canadensis were prepared and used as treatment solutions to assess their effects on seed germination and seedling growth in four target species, mulberry (Morus alba); morning glory (Pharbitis nil), wheat (Triticum aestivum) and rape (Brassica campestris). Reduction and/or growth in germination and growth of the target plant species in the presence of both aqueous and ethanolic extracts at different concentrations indicated that the responses were species-specific and concentration-dependent. Generally, ethanolic extracts (especially from leaves) imposed stronger effects on both seed germination and seedling growth. Extracts with lower concentration at 0.001 g/ml dw could stimulate the seedling growth of rape and morning glory, whereas extracts at any given concentrations have inhibitory effects on wheat and mulberry. It is suggested that the aqueous and ethanolic extracts of all the three parts ofS. canadensis have significant allelopathic effects. Although both inhibition and stimulation occurred in the germination and growth of the target species, extracts with higher concentrations definitely inhibit seed germination and seedling growth of all target plants. We suggest that allelopathy plays a more important role than other mechanisms do in the out-competition of S. canadensis over other plants, and make it invasive in new habitats.

  12. A field experiment demonstrating plant life-history evolution and its eco-evolutionary feedback to seed predator populations.

    Science.gov (United States)

    Agrawal, Anurag A; Johnson, Marc T J; Hastings, Amy P; Maron, John L

    2013-05-01

    The extent to which evolutionary change occurs in a predictable manner under field conditions and how evolutionary changes feed back to influence ecological dynamics are fundamental, yet unresolved, questions. To address these issues, we established eight replicate populations of native common evening primrose (Oenothera biennis). Each population was planted with 18 genotypes in identical frequency. By tracking genotype frequencies with microsatellite DNA markers over the subsequent three years (up to three generations, ≈5,000 genotyped plants), we show rapid and consistent evolution of two heritable plant life-history traits (shorter life span and later flowering time). This rapid evolution was only partially the result of differential seed production; genotypic variation in seed germination also contributed to the observed evolutionary response. Since evening primrose genotypes exhibited heritable variation for resistance to insect herbivores, which was related to flowering time, we predicted that evolutionary changes in genotype frequencies would feed back to influence populations of a seed predator moth that specializes on O. biennis. By the conclusion of the experiment, variation in the genotypic composition among our eight replicate field populations was highly predictive of moth abundance. These results demonstrate how rapid evolution in field populations of a native plant can influence ecological interactions.

  13. Contamination of wild plants near neonicotinoid seed-treated crops, and implications for non-target insects.

    Science.gov (United States)

    Botías, Cristina; David, Arthur; Hill, Elizabeth M; Goulson, Dave

    2016-10-01

    Neonicotinoid insecticides are commonly-used as seed treatments on flowering crops such as oilseed rape. Their persistence and solubility in water increase the chances of environmental contamination via surface-runoff or drainage into areas adjacent to the crops. However, their uptake and fate into non-target vegetation remains poorly understood. In this study, we analysed samples of foliage collected from neonicotinoid seed-treated oilseed rape plants and also compared the levels of neonicotinoid residues in foliage (range: 1.4-11ng/g) with the levels found in pollen collected from the same plants (range: 1.4-22ng/g). We then analysed residue levels in foliage from non-target plants growing in the crop field margins (range: ≤0.02-106ng/g). Finally, in order to assess the possible risk posed by the peak levels of neonicotinoids that we detected in foliage for farmland phytophagous and predatory insects, we compared the maximum concentrations found against the LC50 values reported in the literature for a set of relevant insect species. Our results suggest that neonicotinoid seed-dressings lead to widespread contamination of the foliage of field margin plants with mixtures of neonicotinoid residues, where levels are very variable and discontinuous, but sometimes overlap with lethal concentrations reported for some insect species. Understanding the distribution of pesticides in the environment and their potential effects on biological communities is crucial to properly assess current agricultural management and schemes with biodiversity conservation aims in farmland.

  14. Directed seed dispersal of Piper by Carollia perspicillata and its effect on understory plant diversity and folivory.

    Science.gov (United States)

    Salazar, Diego; Kelm, Detlev H; Salazar, Diego

    2013-11-01

    Directed dispersal occurs when seeds are differentially deposited to sites where offspring survivorship is higher than at randomly chosen sites. Traditionally, characteristics of the dispersal target sites that could increase survivorship of the dispersed plants are thought to be intrinsic to the sites. If directed dispersal is constant over extended periods of time, however, it is likely that nonrandom patterns of dispersal could modify the ecological characteristics of the target site in ways that could increase survivorship and fitness of the dispersed plants. Here we report patterns of Piper diversity (richness, equitability, and similarity) and Piper folivory within plots near natural or artificial roosts of Carollia perspicillata vs. similar plots without bat roosts. Plots with bat roosts, both natural and artificial, had significantly higher Piper species diversity. Additionally, we found that plots with a higher Piper species diversity showed less specialist folivory, higher generalist folivory, and lower total herbivore leaf damage than plots with low Piper diversity. Finally, plots with bat roosts also showed less specialist folivory, lower generalist folivory, and lower total folivory when compared to plots without roosts. We propose that long-lasting nonrandom patterns of seed dispersal can change the local ecological characteristics of target sites via changes in plant diversity, and that these changes are likely to reduce the local rates of folivory and, therefore, increase seed and adult plant survivorship.

  15. Symbiotic in vitro seed propagation of Dendrobium: fungal and bacterial partners and their influence on plant growth and development.

    Science.gov (United States)

    Teixeira da Silva, Jaime A; Tsavkelova, Elena A; Zeng, Songjun; Ng, Tzi Bun; Parthibhan, S; Dobránszki, Judit; Cardoso, Jean Carlos; Rao, M V

    2015-07-01

    The genus Dendrobium is one of the largest genera of the Orchidaceae Juss. family, although some of its members are the most threatened today. The reason why many species face a vulnerable or endangered status is primarily because of anthropogenic interference in natural habitats and commercial overexploitation. The development and application of modern techniques and strategies directed towards in vitro propagation of orchids not only increases their number but also provides a viable means to conserve plants in an artificial environment, both in vitro and ex vitro, thus providing material for reintroduction. Dendrobium seed germination and propagation are challenging processes in vivo and in vitro, especially when the extreme specialization of these plants is considered: (1) their biotic relationships with pollinators and mycorrhizae; (2) adaptation to epiphytic or lithophytic life-styles; (3) fine-scale requirements for an optimal combination of nutrients, light, temperature, and pH. This review also aims to summarize the available data on symbiotic in vitro Dendrobium seed germination. The influence of abiotic factors as well as composition and amounts of different exogenous nutrient substances is examined. With a view to better understanding how to optimize and control in vitro symbiotic associations, a part of the review describes the strong biotic relations of Dendrobium with different associative microorganisms that form microbial communities with adult plants, and also influence symbiotic seed germination. The beneficial role of plant growth-promoting bacteria is also discussed.

  16. Potential role of frugivorous birds (Passeriformes on seed dispersal of six plant species in a restinga habitat, southeastern Brazil

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    Verônica Souza da Mota Gomes

    2008-03-01

    Full Text Available Restingas are considered stressful habitats associated with the Brazilian Atlantic forest, and their ecological interactions are poorly known. The goal of the present study was to determine the potential role of frugivorous birds as seed dispersers in a restinga habitat. Data were collected in Parque Nacional da Restinga de Jurubatiba, southeastern Brazil, where the main physiognomy (Open Clusia Formation is characterized by the presence of patches of vegetation covering 20 to 48 % of the sandy soil and reaching a height of 5 m. Birds were captured with mist nets (12 x 2.5 m; 36 mm mesh; 1 680 net-hrs and had their fecal and regurgitate samples inspected for seeds. Six plant species found in these bird samples were studied. The germination of seeds obtained from plants was compared to those from the birds. Both groups of seeds were set on Petri dishes at room temperature and washed when infected with fungi. In general, there was no effect on germination rate, and the effect on germination speed was negative. Germination of seeds from Pilosocereus arrabidae treated by the birds seemed to be influenced by storage of defecated seeds, while few Miconia cinnamomifolia seeds both from plants and from birds germinated. Ocotea notata presented a great variation in time to the onset of germination, perhaps an advantage against dissecation. Aechmea nudicaulis, Clusia hilariana and Erythroxylum subsessile probably take advantage of the arrival to favorable microhabitats, not by the gut effect on the seeds. All plant species studied are numerically important for the community and some of them are main actors in the succession of vegetation patches. Among the birds, Mimus gilvus is an important resident species, endemic to restingas in Brazil, while Turdus amaurochalinus is a visitor and may be important for plants that fructify during its passage by the study site. Although the effect of pulp removal was only tested for one species (Achmea nudicaulis in the

  17. Impacts of thiamethoxam seed treatment and host plant resistance on the soybean aphid fungal pathogen, Pandora neoaphidis.

    Science.gov (United States)

    Koch, Karrie A; Ragsdale, David W

    2011-12-01

    Since the introduction of soybean aphid, Aphis glycines Matsumura, from Asia, insecticide use in soybean has increased substantially in the north central United States. Insecticide seed treatments and aphid resistant soybean varieties are management tactics that may reduce reliance on foliar applications of broad-spectrum insecticides. Exploring potential nontarget impacts of these technologies will be an important step in incorporating them into aphid management programs. We investigated impacts of thiamethoxam seed treatment and Rag1 aphid resistant soybean on a fungal pathogen of soybean aphid, Pandora neoaphidis (Remaudière & Hennebert) Humber, via open plot and cage studies. We found that although thiamethoxam seed treatment did significantly lower aphid pressure in open plots compared with an untreated control, this reduction in aphid density translated into nonsignificant decreases in fungal disease prevalence in aphids. Furthermore, when aphid densities were approximately equal in seed treated and untreated soybean, no impact on aphid fungal disease was observed. In open plots, Rag1 resistant soybean experienced lower aphid pressure and aphid disease prevalence compared with a nonresistant isoline. However, in cages when aphid densities were equivalent in both resistant and susceptible soybean, resistance had no impact on aphid disease prevalence. The addition of thiamethoxam seed treatment to resistant soybean yielded aphid densities and aphid disease prevalence similar to untreated, resistant soybean. These studies provide evidence that thiamethoxam seed treatments and Rag1 resistance can impact P. neoaphidis via decreased aphid densities; however, this impact is minimal, implying use of seed treatments and host plant resistance are compatible with P. neoaphidis.

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

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    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.

  19. Nectar robbing, forager efficiency and seed set: Bumblebees foraging on the self incompatible plant Linaria vulgaris (Scrophulariaceae)

    Science.gov (United States)

    Stout, Jane C.; Allen, John A.; Goulson, Dave

    2000-07-01

    In southern England, Linaria vulgaris (common yellow toadflax) suffers from high rates of nectar robbery by bumblebees. In a wild population of L. vulgaris we found that 96 % of open flowers were robbed. Five species of bumblebee were observed foraging on these flowers, although short-tongued species ( Bombus lapidarius, B. lucorum and B. terrestris) robbed nectar whilst longer-tongued ones behaved as legitimate pollinators ( B. hortorum and B. pascuorum). Nectar rewards were highly variable; on average there was less nectar in robbed than in unrobbed flowers, but this difference was not statistically significant. The proportion of flowers containing no nectar was significantly higher for robbed flowers compared with unrobbed flowers. Secondary robbers and legitimate pollinators had similar handling times on flowers and, assuming they select flowers at random to forage on, received approximately the same nectar profit per minute, largely because most flowers had been robbed. There was no significant difference in the number of seeds in pods of robbed flowers and in pods of flowers that were artificially protected against robbing. However, more of the robbed flowers set at least some seed than the unrobbed flowers, possibly as a consequence of the experimental manipulation. We suggest that nectar robbing has little effect on plant fecundity because legitimate foragers are present in the population, and that seed predation and seed abortion after fertilization may be more important factors in limiting seed production in this species.

  20. Seasonal dynamics of the plant community and soil seed bank along a successional gradient in a subalpine meadow on the Tibetan Plateau.

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    Miaojun Ma

    Full Text Available BACKGROUND: Knowledge about how change the importance of soil seed bank and relationship between seed mass and abundance during vegetation succession is crucial for understanding vegetation dynamics. Many studies have been conducted, but their ecological mechanisms of community assembly are not fully understood. METHODOLOGY: We examined the seasonal dynamics of the vegetation and soil seed bank as well as seed size distribution along a successional gradient. We also explored the potential role of the soil seed bank in plant community regeneration, the relationship between seed mass and species abundance, and the relative importance of deterministic and stochastic processes along a successional gradient. PRINCIPAL FINDINGS: Species richness of seed bank increased (shallow layer and the total and seed density decreased (each layer and the total significantly with succession. Species richness and seed density differed significantly between different seasons and among soil depths. Seed mass showed a significant negative relationship with relative abundance in the earliest successional stage, but the relationships were not significant in later stages. Seed mass showed no relationship with relative abundance in the whole successional series in seed bank. Results were similar for both July 2005 and April 2006. CONCLUSIONS: The seed mass and abundance relationship was determined by a complex interaction between small and larger seeded species and environmental factors. Both stochastic processes and deterministic processes were important determinants of the structure of the earliest stage. The importance of seed bank decreased with succession. The restoration of abandoned farmed and grazed meadows to the species-rich subalpine meadow in Tibetan Plateau can be successfully achieved from the soil seed bank. However, at least 20 years are required to fully restore an abandoned agricultural meadow to a natural mature subalpine meadow.

  1. Antibacterial, Antioxidant, and Anticholinesterase Activities of Plant Seed Extracts from Brazilian Semiarid Region

    Directory of Open Access Journals (Sweden)

    Davi Felipe Farias

    2013-01-01

    Full Text Available The antimicrobial, antioxidant, and anticholinesterase activities of ethanolic seed extracts of twenty-one plant species from Brazilian semiarid region were investigated. The extracts were tested for antimicrobial activity against six bacteria strains and three yeasts. Six extracts presented activity against the Gram (− organism Salmonella choleraesuis and the Gram (+ organisms Staphylococcus aureus and Bacillus subtilis. The MIC values ranged from 4.96 to 37.32 mg/mL. The Triplaris gardneriana extract presented activity against the three species, with MIC values 18.8, 13.76, and 11.15 mg/mL, respectively. Five extracts presented antioxidant activity, with EC50 values ranging from 69.73 μg/mL (T. gardneriana to 487.51 μg/mL (Licania rigida. For the anticholinesterase activity, eleven extracts were capable of inhibiting the enzyme activity. From those, T. gardneriana, Parkia platycephala and Connarus detersus presented the best activities, with inhibition values of 76.7, 71.5, and 91.9%, respectively. The extracts that presented antimicrobial activity were tested for hemolytic assay against human A, B, and O blood types and rabbit blood. From those, only the Myracrodruon urundeuva extract presented activity (about 20% of hemolysis at the lowest tested concentration, 1.9 µg/mL. Infrared spectroscopy of six representative extracts attested the presence of tannins, polyphenols, and flavonoids, which was confirmed by a qualitative phytochemical assay.

  2. Callus induction and plant regeneration from mature bluegrass (Poa pratensis L.) seeds

    Institute of Scientific and Technical Information of China (English)

    Sun Bi-po; Zhang Wan-jun; Dong Jiang-li; Jin Yong-sheng; Wang Tao

    2006-01-01

    A protocol was discussed for high efficient plant regeneration from seven bluegrass (Poa pratensis L.) cultivars via an indirect callus induction and somatic embryogenesis method. Mature seeds were used as explants for callus initiation. Callus induction and proliferation efficiencies were investigated on NB, modified MS (MMS) and MS media, supplemented with 2.0 mg.L-12,4-dichlorophenoxyacetic acid (2,4-D). The MMS medium performed best. Based on the MMS medium, direct and indirect callus the direct callus induction method, the most suitable 2,4-D concentrations varied among cultivars. Under the indirect callus induction method, a significantly high callus induction frequency (93.33%-98.33%) was obtained and there were barely any statistically significant differences among the tested genetically diverse cultivars. Somatic embryos were promoted on the MMS medium supplemedium containing different concentrations of thidiazuron (TDZ), and the differentiation frequencies varied in the range from 20.15% to 77.65%. The 0.25 mg·L-1 TDZ was generally the most suitable concentration for the tested cultivars.

  3. Metapopulation structure of a seed-predator weevil and its host plant in arms race coevolution.

    Science.gov (United States)

    Toju, Hirokazu; Ueno, Saneyoshi; Taniguchi, Fumiya; Sota, Teiji

    2011-06-01

    Although the importance of gene flow in the geographic structuring of host-parasite interactions has been well discussed, little is known about how dispersal drives the spatial dynamics of other types of coevolutionary interactions in nature. We evaluated the roles of gene flow in the geographically structured processes of a predator-prey arms race involving a seed-predatory weevil with a long mouthpart and its host camellia plant with a thick fruit coat. Molecular genetic analyses showed that both weevil and camellia populations were structured at a spatial scale of several kilometers. Importantly, the spatial pattern of the migration of weevils, but not that of camellias, imposed significant effects on the geographic configuration of the levels of coevolutionary escalation. This result suggests that even if migration is limited in one species (camellia), local coevolution with the other species that migrates between neighboring localities (weevil) can reduce the interpopulation difference in the local adaptive optima of the former species. Thus, gene flow of a species potentially homogenizes the local biological environments provided by the species and thereby promotes the evolutionary convergence of its coevolving counterparts. Consequently, by focusing on coevolutionary interactions in natural communities, "indirect" effects of gene flow on the adaptive divergence of organisms could be identified.

  4. Quality Evaluation of Oil from Seeds of Wild Plant Tylosema fassoglensis in Kenya

    Directory of Open Access Journals (Sweden)

    Ojwang D. Otieno

    2015-01-01

    Full Text Available Tylosema fassoglensis is a plant species that is native to Sub-Saharan Africa. The aim of this study was to evaluate the physicochemical properties of oil from T. fassoglensis in Kenya. Seeds of T. fassoglensis were collected from Mombasa, Taita Taveta, Homa Bay, and Siaya regions. Counts of T. fassoglensis in each region were recorded during the entire survey period. The highest distribution was recorded in Homa Bay followed by Siaya region. Distribution was the least in Taita Taveta and Mombasa regions. The analysis of the physicochemical characteristics of the oil was performed according to the official methods of analysis and the recommended practices of the American Oil Chemists Society. Oil content of 36.4% was obtained. The oil had refractive index 1.47 at 40°C, peroxide value 6.34 meq O2/kg, iodine value 94.06 g of I2/100 g, saponification value 145.93 mg KOH/g of oil, acid value 2.49 ± 0.56 mg KOH/g of oil, and unsaponifiable matter 5.87 g/kg. The oil had Lovibond color index of 2.0Y+28.0R. Oil content of T. fassoglensis is comparable with those of most oil crop under commercial production. The physicochemical properties of oil from T. fassoglensis are within the range recommended by FAO/WHO and hence suitable for human consumption.

  5. Energy analysis of teh foodstuff and forage drying industries. Report B: Cereals and seed-cleaning plants; Brancheenergianalyse for korn-, foderstof- og groenttoeringsindustrien. Delrapport B: Kornanlaeg og saasaedsrenserier

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-01

    Energy analyses of the three cereals and seed-cleaning plants chosen as case studies were carried out. From these analyses specific energy conservation possibilities for different processes are presented. Finally, guidelines for energy audits and energy management in the cereals and seed industry have been prepared. (LN)

  6. Effect of desiccation and salinity stress on seed germination and initial plant growth of Cucumis melo

    OpenAIRE

    Sohrabikertabad,S.; A. Ghanbari; Mohassel, Mohamad,H.R.; Mahalati,M.N.; Gherekhloo, J.

    2013-01-01

    Smellmelon, an annual invasive weed of soybean production fields in the north of Iran, reproduces and spreads predominately through seed production. This makes seed bank survival and successful germination essential steps in the invasive process. To evaluate the potential of Smellmelon to invade water-stressed environments, laboratory studies were conducted to investigate the effect of desiccation and salinity at different temperatures on seed germination and seedling growth of Cucumis melo. ...

  7. The effect of plant growth regulators on centaury (Centaurium erythraea Rafn) seeds germination

    OpenAIRE

    Mijajlović Nada; Grubišić Dragoljub V.; Giba Zlatko; Konjević Radomir

    2005-01-01

    Centaury seeds are light-requiring. Long-term red light irradiation caused more than 80% of seeds to germinate. Seeds did not germinate in darkness. Gibberellic acid and GA7 can replace light, but N-substituted phtalimide AC 94,377 was ineffective. Light-induced germination was inhibited by abscisic acid and growth retardants such as ancymidol, tetcyclacis, and paclobutrazole. Growth retardant-caused inhibition can be overcome by the addition of gibberellic acid.

  8. The effect of plant growth regulators on centaury (Centaurium erythraea Rafn seeds germination

    Directory of Open Access Journals (Sweden)

    Mijajlović Nada

    2005-01-01

    Full Text Available Centaury seeds are light-requiring. Long-term red light irradiation caused more than 80% of seeds to germinate. Seeds did not germinate in darkness. Gibberellic acid and GA7 can replace light, but N-substituted phtalimide AC 94,377 was ineffective. Light-induced germination was inhibited by abscisic acid and growth retardants such as ancymidol, tetcyclacis, and paclobutrazole. Growth retardant-caused inhibition can be overcome by the addition of gibberellic acid.

  9. Using Publicly Available Data to Quantify Plant-Pollinator Interactions and Evaluate Conservation Seeding Mixes in the Northern Great Plains.

    Science.gov (United States)

    Otto, C R V; O'Dell, S; Bryant, R B; Euliss, N H; Bush, R M; Smart, M D

    2017-06-01

    Concern over declining pollinators has led to multiple conservation initiatives for improving forage for bees in agroecosystems. Using data available through the Pollinator Library (npwrc.usgs.gov/pollinator/), we summarize plant-pollinator interaction data collected from 2012-2015 on lands managed by the U.S. Fish and Wildlife Service and private lands enrolled in U.S. Department of Agriculture conservation programs in eastern North Dakota (ND). Furthermore, we demonstrate how plant-pollinator interaction data from the Pollinator Library and seed cost information can be used to evaluate hypothetical seeding mixes for pollinator habitat enhancements. We summarize records of 314 wild bee and 849 honey bee (Apis mellifera L.) interactions detected on 63 different plant species. The wild bee observations consisted of 46 species, 15 genera, and 5 families. Over 54% of all wild bee observations were represented by three genera-Bombus, Lassioglossum, and Melissodes. The most commonly visited forbs by wild bees were Monarda fistulosa, Sonchus arvensis, and Zizia aurea. The most commonly visited forbs by A. mellifera were Cirsium arvense, Melilotus officinalis, and Medicago sativa. Among all interactions, 13% of A. mellifera and 77% of wild bee observations were made on plants native to ND. Our seed mix evaluation shows that mixes may often need to be tailored to meet the unique needs of wild bees and managed honey bees in agricultural landscapes. Our evaluation also demonstrates the importance of incorporating both biologic and economic information when attempting to design cost-effective seeding mixes for supporting pollinators in a critically important part of the United States. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  10. ALLELOPATHIC EFFECTS OF WEED (Tridax procumbens L.) EXTRACT ON SEED GERMINATION AND SEEDLING GROWTH OF SOME LEGUMINOUS PLANTS

    OpenAIRE

    D Femina; P. Lakshmipriya; Subha, S; R. Manonmani

    2012-01-01

    Aqueous leaves extract of different concentrations of weed (Tridax procumbens L.) was used to investigate their allelopathic effects on seed germination, root and shoot length and fresh and dry weight of some leguminous plants viz. Vigna radiata L. (Green gram), Dolichos biflorus L. (Horse gram) and Vigna unguiculata L. (Cow pea). Mature fresh leaves of weed were crushed and soaked for 24h; the filtrates were diluted to make different concentrations and used to investigate their effect on the...

  11. Germination and biochemical changes in ‘Formosa’ papaya seeds treated with plant hormones

    Directory of Open Access Journals (Sweden)

    Rafael Fonsêca Zanotti

    2014-04-01

    Full Text Available This study aimed to investigate the effects of growth regulators on germination rates and biochemical compound concentrations in Carica papaya L. seeds (‘Formosa’ group. The seeds were harvested from fruits at maturation stages 3 and 5 (50 and 75% yellow fruit skin, respectively. The effects of 2-chloroethylphosphonic acid (CEPA, KNO3 and gibberellic acid (GA3on seed germination, germination index speed, soluble sugars, starch, lipids, soluble proteins and total proteins of the papaya seeds were evaluated. The seeds from stage 5 showed a higher rate of germination 30 days after sowing than did the seeds from stage 3. Treatment with CEPA decreased seed germination, apparently due to decreased starch mobilization; the opposite response was observed following KNO3 treatment. GA3, alone or in combination with KNO3, stimulated an increase in lipid mobilization. In general, with the exception of CEPA, all growth regulators tested were effective in overcoming seed dormancy, and KNO3 was the most effective. The seeds from stage 3 fruits treated with KNO3 or KNO3 + GA3 had higher rates of germination at 14 days.

  12. [Characteristics of seed germination of rare plant species Reaumuria trigyna in west Ordos].

    Science.gov (United States)

    Zhang, Ying-juan; Wang, Yu-shan; Li, Qing-feng

    2008-12-01

    Reaumuria trigyna is a relic species in the desert shrubbery vegetation in arid regions of northwestern China, and plays an important role in the maintenance of the stability of desert vegetation. In this paper, the seed traits and germination strategy of R. trigyna under different environmental conditions, e.g., light, temperature, soil moisture, and sand bury, were investigated. The results showed that R. trigyna seed had high vigor and high germination rate, and endured reserve. The seed could germinate either in light or in darkness, and the optimal temperature for germination was 20 degrees C - 25 degrees C or 15 degrees C/25 degrees C, with the germination rate being 93%. The seed could start to germinate when soil moisture content was 2%, and the germination rate was the highest (89%) when the moisture content was 12%. The optimal sand burial depth of R. trigyna seed was 1 cm, and no seed would germinate when the sand burial depth was >5 cm. Sand burial depth had significant effects on the seedling's emergence percentage and growth height, but lesser effects on seedling' s mass. Soil moisture and sand burial depth were the main environmental factors limiting the seed germination and seedling emergence of R. trigyna. The high seed germination rate of R. trigyna enhanced the survival risk of its seedlings, which was unfavorable to its handling with the extreme changes of desert environment. Such a character of R. trigyna seed was one of the factors causing the species endangered.

  13. Influence of laser radiation on the growth and development of seeds of agricultural plants

    Science.gov (United States)

    Grishkanich, Alexander; Zhevlakov, Alexander; Polyakov, Vadim; Kascheev, Sergey; Sidorov, Igor; Ruzankina, Julia; Yakovlev, Alexey; Mak, Andrey

    2016-04-01

    The experimental results presented in this study focused on the study of biological processes caused by exposure to the coating layers of the laser green light seed (λ = 532 nm) range for the larch, violet (λ = 405 nm) and red (λ = 640 nm) for spruce. Spend a series of experiments to study the dependence of crop seed quality (spruce and larch from the pine family) from exposure to laser radiation under different conditions. In all the analyzed groups studied seed germination and growth of seedlings exposed to laser exposure, compared with the control group. The results showed that the higher percentage of germination than seeds of the control group.

  14. The choice of process parameters to obtain a stable dispersion system of plant-based bioactivated dicotyledonous seeds

    Directory of Open Access Journals (Sweden)

    L. A. Samofalova

    2016-01-01

    Full Text Available The article dealswith the search for the unification of technological approaches to increase the efficiency of separation of the protein complex and stability of the plant foundations from seed dicotyledonous economically important crops of soybean, hemp, buckwheat. Uneven localization of nitrogenous substances in the seed largely determines the accessibility of protein complexes for extraction. Natural fermentation of spare proteins in cellular structures when the germination process starts leads to the accumulation of soluble nitrogen, and the change in the salt composition of protoplasm facilitates the transition in the solution of insoluble complexes in the form of colloids. It is shown that fine grinding of dry seeds increases the efficiency of extraction by 1.3–1.6 times, while rough grinding increases bioactivity by 1.6–1.8 times. The dispersion containing 8.1±0.7% of dry matter at buckwheat bases and 9.5±1,3% at hemp and soy bases with the water ratio 1:4 to 1:7 satisfy the requirements of taste sensations and fullness of the chemical composition. Based on the results of the extraction of protein of buckwheat seeds the conclusion has been drawn that there is a need for a differentiated approach to selecting conditions for the creation of food framework. Taking into consideration the fact that the amount of calcium in buckwheat seeds is17–25 times smaller than in oil seeds and the quantity of phosphorus is 1.6–2 times smaller, the contribution of electrostatic forces in the protein solubility is small and the additional actions to activate the protein complex are required. To predict the properties of vegetable bases of bioactivated soybean seeds and hemp, the central composite uniform-rotatable planning was applied and the full factorial experiment with factorial scheme 3×3×3 (33 was selected. The preferred combination of values of the input parameters X1, X2, X3 was discovered. They provide for the maximum of Y

  15. Geographical patterns of Yunnan seed plants may be influenced by the Clockwise Rotation of the Simao-Indochina Geoblock

    Directory of Open Access Journals (Sweden)

    Zhu eHua

    2015-09-01

    Full Text Available Floristic patterns of seed plants in Yunnan, southwestern China, were studied to assess the relationship between the floristic geography and geological history. A database of 38 regional floristic studies covering Yunnan was used and the patterns of seed plant distributions across these regional floras were quantified at the generic level. Genera with tropical Asian distributions are the most dominant geographical elements in the Yunnan flora. They show oblique patterns of abundance across Yunnan. They are most abundant in southern and western Yunnan, and their proportion in regional floras declines abruptly in eastern, central and northern Yunnan. The oblique abundance patterns of geographical elements in Yunnan differ from those of genera in southern and eastern China, which had a high correlation with latitudinal gradients controlled by climate. They cannot be explained by climate alone, but can be explained at least partly by the geological history. The oblique abundance patterns of Yunnan seed plants correspond well to the clockwise rotation and southeastward extrusion of the Simao-Indochina geoblock caused by the collision of India with Asia.

  16. Geographical patterns of Yunnan seed plants may be influenced by the Clockwise Rotation of the Simao-Indochina Geoblock

    Science.gov (United States)

    Hua, Zhu

    2015-09-01

    Floristic patterns of seed plants in Yunnan, southwestern China, were studied to assess the relationship between the floristic geography and geological history. A database of 38 regional floristic studies covering Yunnan was used and the patterns of seed plant distributions across these regional floras were quantified at the generic level. Genera with tropical Asian distributions are the most dominant geographical elements in the Yunnan flora. They show oblique patterns of abundance across Yunnan. They are most abundant in southern and western Yunnan, and their proportion in regional floras declines abruptly in eastern, central and northern Yunnan. The oblique abundance patterns of geographical elements in Yunnan differ from those of genera in southern and eastern China, which had a high correlation with latitudinal gradients controlled by climate. They cannot be explained by climate alone, but can be explained at least partly by the geological history. The oblique abundance patterns of Yunnan seed plants correspond well to the clockwise rotation and southeastward extrusion of the Simao-Indochina geoblock caused by the collision of India with Asia.

  17. Evolution of Spermophagus seed beetles (Coleoptera, Bruchinae, Amblycerini) indicates both synchronous and delayed colonizations of host plants.

    Science.gov (United States)

    Kergoat, Gael J; Le Ru, Bruno P; Sadeghi, Seyed E; Tuda, Midori; Reid, Chris A M; György, Zoltán; Genson, Gwenaëlle; Ribeiro-Costa, Cibele S; Delobel, Alex

    2015-08-01

    Seed beetles are a group of specialized chrysomelid beetles, which are mostly associated with plants of the legume family (Fabaceae). In the legume-feeding species, a marked trend of phylogenetic conservatism of host use has been highlighted by several molecular phylogenetics studies. Yet, little is known about the evolutionary patterns of association of species feeding outside the legume family. Here, we investigate the evolution of host use in Spermophagus, a species-rich seed beetle genus that is specialized on two non-legume host-plant groups: morning glories (Convolvulaceae) and mallows (Malvaceae: Malvoideae). Spermophagus species are widespread in the Old World, especially in the Afrotropical, Indomalaya and Palearctic regions. In this study we rely on eight gene regions to provide the first phylogenetic framework for the genus, along with reconstructions of host use evolution, estimates of divergence times and historical biogeography analyses. Like the legume-feeding species, a marked trend toward conservatism of host use is revealed, with one clade specializing on Convolvulaceae and the other on Malvoideae. Comparisons of plants' and insects' estimates of divergence times yield a contrasted pattern: on one hand a quite congruent temporal framework was recovered for morning-glories and their seed-predators; on the other hand the diversification of Spermophagus species associated with mallows apparently lagged far behind the diversification of their hosts. We hypothesize that this delayed colonization of Malvoideae can be accounted for by the respective biogeographic histories of the two groups.

  18. Water, Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

    Institute of Scientific and Technical Information of China (English)

    Maite MART(I)NEZ-EIXARCH; ZHU De-feng; Maria del Mar CATAL(A)-FORNER; Eva PLA-MAYOR; Nuria TOM(A)S-NAVARRO

    2013-01-01

    Field experiments were conducted in the Ebro Delta area (Spain),from 2007 to 2009 with two rice varieties:Gleva and Tebre.The experimental treatments included a series of seed rates,two different water management systems and two different nitrogen fertilization times.The number of leaves on the main stems and their emergence time were periodically tagged.The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles.Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems.Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems.Final leaf number on the main stems was negatively related to plant density.A relationship between leaf appearance and thermal time was established with a strong nonlinear function.In direct-seeded rice,the length of the phyllochron increases exponentially in line with the advance of plant development.A general model,derived from 2-year experimental data,was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf.An exponential model can be used to predict leaf emergence in direct-seeded rice.

  19. Effect of fungal and plant metabolites on broomrapes (Orobanche and Phelipanche spp.) seed germination and radicle growth.

    Science.gov (United States)

    Cimmino, Alessio; Fernández-Aparicio, Mónica; Andolfi, Anna; Basso, Sara; Rubiales, Diego; Evidente, Antonio

    2014-10-29

    Orobanche and Phelipanche species (the broomrapes) are root parasitic plants, some of which cause heavy yield losses on important crops. The development of herbicides based on natural metabolites from microbial and plant origin, targeting early stages on parasitic plant development, might contribute to the reduction of broomrape seed bank in agricultural soils. Therefore, the effect of metabolites belonging to different classes of natural compounds on broomrape seed germination and radicle development was assayed in vitro. Among the metabolites tested, epi-sphaeropsidone, cyclopaldic acid, and those belonging to the sesquiterpene class induced broomrape germination in a species-specific manner. epi-Epoformin, sphaeropsidin A, and cytochalasans inhibited germination of GR24-treated broomrape seeds. The growth of broomrape radicle was strongly inhibited by sphaeropsidin A and compounds belonging to cyclohexene epoxide and cytochalasan classes. Broomrape radicles treated with epi-sphaeropsidone developed a layer of papillae while radicles treated with cytochalasans or with sphaeropsidin A turned necrotic. These findings allow new lead natural herbicides for the management of parasitic weeds to be identified.

  20. Water, Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

    Directory of Open Access Journals (Sweden)

    Maite MARTÍNEZ-EIXARCH

    2013-01-01

    Full Text Available Field experiments were conducted in the Ebro Delta area (Spain, from 2007 to 2009 with two rice varieties: Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.

  1. FY 14 interim report : Evaluation of treatments to mitigate negative plant-soil feedbacks and improve reconstruction seeding success at Kulm Wetland Management District

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Interim report for fiscal year 2014 on the research "Evaluation of treatments to mitigate negative plant-soil feedbacks and improve reconstruction seeding success at...

  2. Interstellar Extinction

    Science.gov (United States)

    Gontcharov, G. A.

    2016-12-01

    This review describes our current understanding of interstellar extinction. This differ substantially from the ideas of the 20th century. With infrared surveys of hundreds of millions of stars over the entire sky, such as 2MASS, SPITZER-IRAC, and WISE, we have looked at the densest and most rarefied regions of the interstellar medium at distances of a few kpc from the Sun. Observations at infrared and microwave wavelengths, where the bulk of the interstellar dust absorbs and radiates, have brought us closer to an understanding of the distribution of the dust particles on scales of the Galaxy and the universe. We are in the midst of a scientific revolution in our understanding of the interstellar medium and dust. Progress in, and the key results of, this revolution are still difficult to predict. Nevertheless, (a) a physically justified model has been developed for the spatial distribution of absorbing material over the nearest few kiloparsecs, including the Gould belt as a dust container, which gives an accurate estimate of the extinction for any object just by its galactic coordinates. It is also clear that (b) the interstellar medium contains roughly half the mass of matter in the galactic vicinity of the solar system (the other half is made up of stars, their remnants, and dark matter) and (c) the interstellar medium and, especially, dust, differ substantially in different regions of space and deep space cannot be understood by only studying near space.

  3. Endophytes from medicinal plants and their potential for producing indole acetic acid, improving seed germination and mitigating oxidative stress* #

    Science.gov (United States)

    Khan, Abdul Latif; Gilani, Syed Abdullah; Waqas, Muhammad; Al-Hosni, Khadija; Al-Khiziri, Salima; Kim, Yoon-Ha; Ali, Liaqat; Kang, Sang-Mo; Asaf, Sajjad; Shahzad, Raheem; Hussain, Javid; Lee, In-Jung; Al-Harrasi, Ahmed

    2017-01-01

    Medicinal plants have been used by marginal communities to treat various ailments. However, the potential of endophytes within these bio-prospective medicinal plants remains unknown. The present study elucidates the endophytic diversity of medicinal plants (Caralluma acutangula, Rhazya stricta, and Moringa peregrina) and the endophyte role in seed growth and oxidative stress. Various organs of medicinal plants yielded ten endophytes, which were identified as Phoma sp. (6 isolates), Alternaria sp. (2), Bipolaris sp. (1), and Cladosporium sp. (1) based on 18S rDNA sequencing and phylogenetic analysis. The culture filtrates (CFs; 25%, 50%, and 100% concentrations) from these endophytes were tested against the growth of normal and dwarf mutant rice lines. Endophytic CF exhibited dose-dependent growth stimulation and suppression effects. CF (100%) of Phoma sp. significantly increased rice seed germination and growth compared to controls and other endophytes. This growth-promoting effect was due to the presence of indole acetic acid in endophytic CF. The gas chromatography/mass spectrometry (GC/MS) analysis showed the highest indole acetic acid content ((54.31±0.21) µmol/L) in Bipolaris sp. In addition, the isolate of Bipolaris sp. exhibited significantly higher radical scavenging and anti-lipid peroxidation activity than the other isolates. Bipolaris sp. and Phoma sp. also exhibited significantly higher flavonoid and phenolic contents. The medicinal plants exhibited the presence of bio-prospective endophytic strains, which could be used for the improvement of crop growth and the mitigation of oxidative stresses. PMID:28124841

  4. Fine-scale spatial genetic structure in predominantly selfing plants with limited seed dispersal: A rule or exception?

    Directory of Open Access Journals (Sweden)

    Sergei Volis

    2016-04-01

    Full Text Available Gene flow at a fine scale is still poorly understood despite its recognized importance for plant population demographic and genetic processes. We tested the hypothesis that intensity of gene flow will be lower and strength of spatial genetic structure (SGS will be higher in more peripheral populations because of lower population density. The study was performed on the predominantly selfing Avena sterilis and included: (1 direct measurement of dispersal in a controlled environment; and (2 analyses of SGS in three natural populations, sampled in linear transects at fixed increasing inter-plant distances. We found that in A. sterilis major seed dispersal is by gravity in close (less than 2 m vicinity of the mother plant, with a minor additional effect of wind. Analysis of SGS with six nuclear SSRs revealed a significant autocorrelation for the distance class of 1 m only in the most peripheral desert population, while in the two core populations with Mediterranean conditions, no genetic structure was found. Our results support the hypothesis that intensity of SGS increases from the species core to periphery as a result of decreased within-population gene flow related to low plant density. Our findings also show that predominant self-pollination and highly localized seed dispersal lead to SGS at a very fine scale, but only if plant density is not too high.

  5. Efficacy of certain plant extracts against seed-borne infection of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... degree of infection by C. destructivum was reduced to some extent by seed treatment ... the aim of finding alternatives to the use of chemicals. ... extracts treatment involving soaking the seeds in each of the con- centration for 6 ...

  6. 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

  7. 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 1×106 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

  8. The role of seed mass on the caching decision by agoutis, Dasyprocta leporina (Rodentia: Agoutidae

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    Mauro Galetti

    2010-06-01

    Full Text Available It has been shown that the local extinction of large-bodied frugivores may cause cascading consequences for plant recruitment and overall plant diversity. However, to what extent the resilient mammals can compensate the role of seed dispersal in defaunated sites is poorly understood. Caviomorph rodents, especially Dasyprocta spp., are usually resilient frugivores in hunted forests and their seed caching behavior may be important for many plant species which lack primary dispersers. We compared the effect of the variation in seed mass of six vertebrate-dispersed plant species on the caching decision by the red-rumped agoutis Dasyprocta leporina Linnaeus, 1758 in a land-bridge island of the Atlantic forest, Brazil. We found a strong positive effect of seed mass on seed fate and dispersal distance, but there was a great variation between species. Agoutis never cached seeds smaller than 0.9 g and larger seeds were dispersed for longer distances. Therefore, agoutis can be important seed dispersers of large-seeded species in defaunated forests.

  9. Two bee-pollinated plant species show higher seed production when grown in gardens compared to arable farmland.

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    John Cussans

    Full Text Available Insect pollinator abundance, in particular that of bees, has been shown to be high where there is a super-abundance of floral resources; for example in association with mass-flowering crops and also in gardens where flowering plants are often densely planted. Since land management affects pollinator numbers, it is also likely to affect the resultant pollination of plants growing in these habitats. We hypothesised that the seed or fruit set of two plant species, typically pollinated by bumblebees and/or honeybees might respond in one of two ways: 1 pollination success could be reduced when growing in a floriferous environment, via competition for pollinators, or 2 pollination success could be enhanced because of increased pollinator abundance in the vicinity.We compared the pollination success of experimental plants of Glechoma hederacea L. and Lotus corniculatus L. growing in gardens and arable farmland. On the farms, the plants were placed either next to a mass-flowering crop (oilseed rape, Brassica napus L. or field beans, Vicia faba L. or next to a cereal crop (wheat, Triticum spp.. Seed set of G. hederacea and fruit set of L. corniculatus were significantly higher in gardens compared to arable farmland. There was no significant difference in pollination success of G. hederacea when grown next to different crops, but for L. corniculatus, fruit set was higher in the plants growing next to oilseed rape when the crop was in flower.The results show that pollination services can limit fruit set of wild plants in arable farmland, but there is some evidence that the presence of a flowering crop can facilitate their pollination (depending on species and season. We have also demonstrated that gardens are not only beneficial to pollinators, but also to the process of pollination.

  10. Overcoming seed dormancy using gibberellic acid and the performance of young Syagrus coronata plants under severe drought stress and recovery.

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    Medeiros, Maria J; Oliveira, Marciel T; Willadino, Lilia; Santos, Mauro G

    2015-12-01

    Syagrus coronata, a native palm tree of the Brazilian semi-arid region, exhibits low germinability due to seed dormancy. This study aimed to increase the germinability, analyze the morphology of seedlings and evaluate the performance of young plants under a water deficit. We used immersion in water and gibberellic acid (GA3) as pyrene (seed with endocarp) pre-germination treatments, and we analyzed the water relations, gas exchange, chlorophyll fluorescence and carbon balance components of young plants under drought and rehydration conditions. The immersion of pyrenes in 0.3 mM GA3 solution for 24 h enhanced the emergence and survival of plants and the emergence rate index. The germination of S. coronata is of the remote tubular type, and seedling growth originates with the protrusion of the cotyledon petiole, followed by the subsequent emergence of the root, leaf sheaths and eophyll. The plants exhibited high tolerance to no irrigation for 37 days, which was attributed to strong stomatal control, a higher proportion of energy dissipation and a higher content of photoprotective pigments. Despite the reduced stomatal conductance (regardless of soil water availability), the photosynthetic rate remained high throughout the day, which indicated a low correlation between these two parameters. After rehydration, we observed that both the leaf water content and photosynthesis recovered, which showed an absence of irreversible damage of the photosynthetic apparatus. The use of 0.3 mM GA3 is recommended as a treatment for overcoming seed dormancy in this species. Young S. coronata plants showed high tolerance during drought and resilience after rehydration by adjusting their leaf metabolism, which could explain the endemism of this species in semi-arid regions and its ability to remain evergreen throughout the year. Furthermore, with high photosynthetic rate in the most favorable time of day, even under drought stress.

  11. Defaunation of large mammals leads to an increase in seed predation in the Atlantic forests

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    Mauro Galetti

    2015-01-01

    Full Text Available Defaunation can trigger cascading events in natural communities and may have strong consequences for plant recruitment in tropical forests. Several species of large seed predators, such as deer and peccaries, are facing dramatic population collapse in tropical forests yet we do not have information about the consequences of these extinctions for seed predation. Using remote camera traps we tested if defaunated forests have a lower seed predation rate of a keystone palm (Euterpe edulis than pristine areas. Contrary to our expectation, we found that seed predation rates were 2.5 higher in defaunated forests and small rodents were responsible for most of the seeds eaten. Our results found that defaunation leads to changes in the seed predator communities with potential consequences for plant–animal interactions.

  12. Eastern Asian endemic seed plant genera and their paleogeographic history throughout the Northern Hemisphere

    Institute of Scientific and Technical Information of China (English)

    Steven R. MANCHESTER; Zhi-Duan CHEN; An-Ming LU; Kazuhiko UEMURA

    2009-01-01

    We review the fossil history of seed plant genera that are now endemic to eastern Asia. Although the majority of eastern Asian endemic genera have no known fossil record at all, 54 genera, or about 9%, are reliably known from the fossil record. Most of these are woody (with two exceptions), and most are today either broadly East Asian, or more specifically confined to Sino-Japanese subcategory rather than being endemic to the Sino-Himalayan area. Of the "eastern Asian endemic" genera so far known from the fossil record, the majority formerly occurred in Europe and/or North America, indicating that eastern Asia served as a late Tertiary or Quaternary refugium for taxa. Hence, many of these genera may have originated in other parts of the Northern Hemisphere and expanded their ranges across continents and former sea barriers when tectonic and climatic conditions al-lowed, leading to their arrival in eastern Asia. Although clear evidence for paleoendemism is provided by the gymnosperms Amentotaxus, Cathaya, Cephalotaxus, Cunninghamia, Cryptomeria, Glyptostrobus, Ginkgo, Ketel-eeria, Metasequoia, Nothotsuga, Pseudolarix, Sciadopitys, and Taiwania, and the angiosperms Cercidiphyllum, Choerospondias, Corylopsis, Craigia, Cyclocarya, Davidia, Dipelta, Decaisnea, Diplopanax, Dipteronia, Em-menopterys, Eucommia, Euscaphis, Hemiptelea, Hovenia, Koelreuteria, Paulownia, Phellodendron, Platycarya, Pteroceltis, Rehderodendron, Sargentodoxa, Schizophragma, Sinomenium, Tapiscia, Tetracentron, Toricellia,Trapella, and Trochodendron, we cannot rule out the possibility that neoendemism plays an important role espe-cially for herbaceous taxa in the present-day flora of Asia, particularly in the Sino-Himalayan region. In addition to reviewing paleobotanical occurrences from the literature, we document newly recognized fossil occurrences that expand the geographic and stratigraphic ranges previously known for Dipelta, Pteroceltis, and Toricellia.

  13. Transgenic tobacco overexpressing Brassica juncea HMG-CoA synthase 1 shows increased plant growth, pod size and seed yield.

    Science.gov (United States)

    Liao, Pan; Wang, Hui; Wang, Mingfu; Hsiao, An-Shan; Bach, Thomas J; Chye, Mee-Len

    2014-01-01

    Seeds are very important not only in the life cycle of the plant but they represent food sources for man and animals. We report herein a mutant of 3-hydroxy-3-methylglutaryl-coenzyme A synthase (HMGS), the second enzyme in the mevalonate (MVA) pathway that can improve seed yield when overexpressed in a phylogenetically distant species. In Brassica juncea, the characterisation of four isogenes encoding HMGS has been previously reported. Enzyme kinetics on recombinant wild-type (wt) and mutant BjHMGS1 had revealed that S359A displayed a 10-fold higher enzyme activity. The overexpression of wt and mutant (S359A) BjHMGS1 in Arabidopsis had up-regulated several genes in sterol biosynthesis, increasing sterol content. To quickly assess the effects of BjHMGS1 overexpression in a phylogenetically more distant species beyond the Brassicaceae, wt and mutant (S359A) BjHMGS1 were expressed in tobacco (Nicotiana tabacum L. cv. Xanthi) of the family Solanaceae. New observations on tobacco OEs not previously reported for Arabidopsis OEs included: (i) phenotypic changes in enhanced plant growth, pod size and seed yield (more significant in OE-S359A than OE-wtBjHMGS1) in comparison to vector-transformed tobacco, (ii) higher NtSQS expression and sterol content in OE-S359A than OE-wtBjHMGS1 corresponding to greater increase in growth and seed yield, and (iii) induction of NtIPPI2 and NtGGPPS2 and downregulation of NtIPPI1, NtGGPPS1, NtGGPPS3 and NtGGPPS4. Resembling Arabidopsis HMGS-OEs, tobacco HMGS-OEs displayed an enhanced expression of NtHMGR1, NtSMT1-2, NtSMT2-1, NtSMT2-2 and NtCYP85A1. Overall, increased growth, pod size and seed yield in tobacco HMGS-OEs were attributed to the up-regulation of native NtHMGR1, NtIPPI2, NtSQS, NtSMT1-2, NtSMT2-1, NtSMT2-2 and NtCYP85A1. Hence, S359A has potential in agriculture not only in improving phytosterol content but also seed yield, which may be desirable in food crops. This work further demonstrates HMGS function in plant reproduction

  14. THE ANALYSIS OF THE EXISTING SCIENTIFIC HYPOTHESES ON THE INFLUENCE OF OZONE AND AIR PROCESSING ON SEEDS OF AGRICULTURAL PLANTS

    Directory of Open Access Journals (Sweden)

    Normov D. A.

    2016-02-01

    Full Text Available There are various ways of achieving various crops productivity increase. Here belong the following ways: chemical, physical and physical and chemical. In our opinion, the most perspective way of presowing processing is processing by mix of air and ozone, which belongs to physical and chemical ways of impact on seed material. To obtain the mix of air and ozone is also possible in several ways. The most economically expedient way of ozone synthesis is in the barrier electric ozonizer discharge. However, to achieve a positive effect in ozone influence it is necessary to observe accurately technological parameters as dosages excess can lead to oppression of growth processes in seed. Therefore, it is necessary to consider all known hypotheses connected with ozone influence on agricultural plants and their development process. Researches in this field show that under the influence of ozone on seed material, inside a seed the cleavage of the protein mass takes place. Proteins pass into more available form and as a result it is easier for sprout to receive the nutrients in proteins that promotes the accelerated growth. It is also necessary to note that ozone saturates grain with active forms of oxygen. It is necessary as well to remember bactericidal properties of ozone, which provide destruction of harmful microflora surrounding grain. All these factors lead to improvement of grain sowing qualities and, as a result, increase yielding capacity

  15. Endosperm degradation during seed development of Echinocystis lobata (Cucurbitaceae) as a manifestation of programmed cell death (PCD) in plants.

    Science.gov (United States)

    Wojciechowska, Marzena; Olszewska, Maria J

    2003-01-01

    Programmed cell death (PCD) is an active, genetically controlled process that ultimately leads to elimination of unnecessary or damaged cells from multicellular organism. It occurs during normal growth and development or in response to a variety of environmental triggers and is indispensable for survival of the organism. In Echinocystis lobata the endosperm, an ephemeral tissue in angiosperm plants, undergoes distinct cytological, physiological and molecular changes during seed development and maturation. As a result, mature seeds are deprived of this tissue. The endosperm was analyzed at the consecutive stages of seed development. The morphological changes of cells were studied at light and electron microscope levels. In this paper we report that endosperm cells undergo morphological and biochemical changes characteristic of apoptosis, a particular type of PCD, i.e. cell shrinkage, chromatin condensation, nuclear fragmentation, and cytoplasm degradation, while the ultrastructure of mitochondria seems to be less changed. Furthermore, the progression of DNA degradation has been shown by agarose gel electrophoresis (ladder pattern of DNA fragmentseparation), TUNEL and comet assay. It isconcluded that during seed maturation, endosperm degradation process is accompanied by typical PCD-related changes of cell morphology and internucleosomal DNA cleavage.

  16. Evaluating effect of biofertilizer on nodulation and soybean (Glycine max L plants growth characteristics under water deficit stress of seed

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    M. Tajik Khaveh

    2016-05-01

    Full Text Available In order to evaluate the effects of biofertilizer on soybean (Glycine max L. seed vigor that produced under water deficit condition and related traits, an experiment was conducted in a factorial layout based of complete randomized block design with four replications at the research greenhouse of Aboureihan campus- Tehran University, Iran. Experimental treatments were include biofertilizer (seed inoculation with Bradyrhizobium japonicum, co-inoculation with Bradyrhizobium japonicum and Pseudomonas fluorescens, co-inoculation with Bradyrhizobium japonicum and Glomus mosseae, Cultivar (Zalta Zalha and Clark×Hobbit line and water deficit stress [irrigation plants after 50 (normal irrigation, 100 (medium stress, 150 (sever stress mm evaporation from pan class A, in parents field]. Results showed that the water deficit stress had negative effects on seed quality and seedling emergence percentage, mean daily seedling emergence, root, leaf and shoot dry weight, number of nodule were decreased. ZaltaZalha cultivar had higher shoot dry weight and number of leaf compared with other cultivars. Applications of biofertilzer was effective on stem diameter, root, leaf and shoot dry weight, number of leaf and nodule and those attributes increased by co-inoculation of Bradyrhizobium japonicum and Glomus mosseae. Also, use of biofertilizer in stress levels was effective on stem dry weight. Stem dry weight was increased by Co-inoculation of cultivar seeds with Bradyrhizobium japonicum and Glomus mosseae.

  17. Wheat seeds harbour bacterial endophytes with potential as plant growth promoters and biocontrol agents of Fusarium graminearum.

    Science.gov (United States)

    Díaz Herrera, Silvana; Grossi, Cecilia; Zawoznik, Myriam; Groppa, María Daniela

    2016-01-01

    The role of endophytic communities of seeds is still poorly characterised. The purpose of this work was to survey the presence of bacterial endophytes in the seeds of a commercial wheat cultivar widely sown in Argentina and to look for plant growth promotion features and biocontrol abilities against Fusarium graminearum among them. Six isolates were obtained from wheat seeds following a culture-dependent protocol. Four isolates were assignated to Paenibacillus genus according to their 16S rRNA sequencing. The only gammaproteobacteria isolated, presumably an Enterobactereaceae of Pantoea genus, was particularly active as IAA and siderophore producer, and also solubilised phosphate and was the only one that grew on N-free medium. Several of these isolates demonstrated ability to restrain F. graminearum growth on dual culture and in a bioassay using barley and wheat kernels. An outstanding ability to form biofilm on an inert surface was corroborated for those Paenibacillus which displayed greater biocontrol of F. graminearum, and the inoculation with one of these isolates in combination with the Pantoea isolate resulted in greater chlorophyll content in barley seedlings. Our results show a significant ecological potential of some components of the wheat seed endophytic community. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

    Science.gov (United States)

    Tjelele, Julius; Ward, David; Dziba, Luthando

    2015-01-01

    The increasing rate of woody plant encroachment in grasslands or savannas remains a challenge to livestock farmers. The causes and control measures of woody plant encroachment are of common interest, especially where it negatively affects 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 trials were subjected to the following treatments: 1) seed passage through the gut of cattle and goats and unpassed/ untreated seeds (i.e. not ingested), 2) dung and control (no dung), 3) grass and control (mowed grass), 4) fire and control (no fire), 5) trampling and control (no trampling). The interaction of animal species, grass and fire had an effect on seedling recruitment (P effect on seedling recruitment than seeds retrieved from goats and planted with