Longevity Of Seeds Research Articles

Glyphosate Resistance Does Not Affect Palmer Amaranth (Amaranthus palmeri) Seedbank Longevity

A greater understanding of the factors that regulate weed seed return to and persistence in the soil seedbank is needed for the management of difficult-to-control herbicide-resistant weeds. Studies were conducted in Tifton, GA to (1) evaluate whether glyphosate resistance, burial depth, and burial duration affect the longevity of Palmer amaranth seeds and (2) estimate the potential postdispersal herbivory of seeds. Palmer amaranth seeds from glyphosate-resistant and glyphosate-susceptible populations were buried in nylon bags at four depths ranging from 1 to 40 cm for intervals ranging between 0 and 36 mo, after which the bags were exhumed and seeds evaluated for viability. There were no detectable differences in seed viability between glyphosate-resistant and glyphosate-susceptible Palmer amaranth seeds, but there was a significant burial time by burial depth interaction. Palmer amaranth seed viability for each of the burial depths declined over time and was described by exponential decay regression models. Seed viability at the initiation of the study was ≥ 96%; after 6 mo of burial, viability declined to 65 to 78%. As burial depth increased, so did Palmer amaranth seed viability. By 36 mo, seed viability ranged from 9% (1-cm depth) to 22% (40-cm depth). To evaluate potential herbivory, seed traps with three levels of exclusion were constructed: (1) no exclusion, (2) rodent exclusion, and (3) rodent and large arthropod exclusion. Each seed trap contained 100 Palmer amaranth seeds and were deployed for 7 d at irregular intervals throughout the year, totaling 27 sample times. There were seasonal differences in seed recovery and differences among type of seed trap exclusion, but no interactions. Seed recovery was lower in the summer and early autumn and higher in the late winter and early spring, which may reflect the seasonal fluctuations in herbivore populations or the availability of other food sources. Seed recovery was greatest (44%) from the most restrictive traps, which only allowed access by small arthropods, such as fire ants. Traps that excluded rodents, but allowed access by small and large arthropods, had 34% seed recovery. In the nonexclusion traps, only 25% of seed were recovered, with evidence of rodent activity around these traps. Despite the physically small seed size, Palmer amaranth is targeted for removal from seed traps by seed herbivores, which could signify a reduction in the overall seed density. To be successful, Palmer amaranth management programs will need to reduce soil seedbank population densities. Future studies need to address factors that enhance the depletion of the soil seedbank and evaluate how these interact with other weed control practices.

Biochemical Phenotyping of Soybean [Glycine max (L.) Merill] Genotypes to Establish the Role of Lipid Peroxidation and Antioxidant Enzymes in Seed Longevity

Thirty-three soybean (Glycine max (L.) Merill) genotypes, comprising 14 black-seeded and 19 yellow-seeded ones, were selected on the basis of their reported storability for the biochemical phenotyping to establish the role of lipid peroxidation and antioxidant enzymes in seed longevity. The present study revealed clear genotypic variability with respect to storability among different soybean genotypes. Good-storer genotypes with lower electrolyte leakage were characterized by smaller seed size with black testa color. The level of volatile aldehydes released and lipoxygenase II enzyme activity were higher in the yellow-seeded genotypes than in the black-seeded genotypes, though it increased in all during ageing. A sharp increase in the release of volatile aldehydes and lipoxygenase II activity, concomitant with the reduction in germination under uncontrolled laboratory conditions of storage indicated the role of lipid peroxidation in seed longevity behavior (r =- 0.6638** and r =- 0.7639**, respectively). No significant difference was noted in the mean hydroper- oxide lyase activity of black and yellow-seeded genotypes. However, maintenance of high hydroperoxide lyase activity during storage resulted in higher release of volatile aldehydes and poor storability of seeds. Significantly higher antioxidant enzyme activity was recorded in the black-seeded genotypes than in the yellow-seeded ones, though there was a reduction in hydroperoxide lyase activity during storage in all the genotypes. The viability of black-seeded genotypes after storage for 1 year was better than the yellow-seeded genotypes.

Genetic variation for secondary seed dormancy and seed longevity in a set of black‐seeded European winter oilseed rape cultivars

AbstractSecondary seed dormancy in oilseed rape is a phenomenon that allows seeds to survive in the soil for many years without germination. Following soil cultivation, dormant seeds may germinate in subsequent years, and they are the main reason for the occurrence of volunteer oilseed rape plants in successive crops. Inheritance of secondary dormancy may be related to seed longevity (SL) in the soil. Genetic reduction in secondary dormancy and SL could provide a mean to reduce the frequency of volunteer plants and especially the dispersal of transgenic oilseed rape. The aim of the present study was to analyse secondary dormancy, germination rate and SL of 28 black‐seeded winter oilseed rape cultivars using in vitro laboratory tests. The material was tested in field experiments at six different locations in Germany in 2008/2009. Significant effects of the genotype and the location on all traits were found. Heritability was high for secondary dormancy (0.97) and moderate for germination rate (0.70) and SL (0.71). Results indicate that a selection for low secondary dormancy would be effective.

Evidence for participation of the methionine sulfoxide reductase repair system in plant seed longevity

Seeds are in a natural oxidative context leading to protein oxidation. Although inevitable for proper progression from maturation to germination, protein oxidation at high levels is detrimental and associated with seed aging. Oxidation of methionine to methionine sulfoxide is a common form of damage observed during aging in all organisms. This damage is reversible through the action of methionine sulfoxide reductases (MSRs), which play key roles in lifespan control in yeast and animal cells. To investigate the relationship between MSR capacity and longevity in plant seeds, we first used two Medicago truncatula genotypes with contrasting seed quality. After characterizing the MSR family in this species, we analyzed gene expression and enzymatic activity in immature and mature seeds exhibiting distinct quality levels. We found a very strong correlation between the initial MSR capacities in different lots of mature seeds of the two genotypes and the time to a drop in viability to 50% after controlled deterioration. We then analyzed seed longevity in Arabidopsis thaliana lines, in which MSR gene expression has been genetically altered, and observed a positive correlation between MSR capacity and longevity in these seeds as well. Based on our data, we propose that the MSR repair system plays a decisive role in the establishment and preservation of longevity in plant seeds.

Longevity of seeds of various winter rye (secale cereale l.) under cooling

The article studies ability to sprouting and seed germinating of Intensivne 95, Intensivne 99 and Siverske varieties stored under cooling. It is established that seed of rye preserves economical and technical longevity for 1 to 2 years, and biological for 5 years. Highest indices of ability to sprout and germinate for all conditions of seed have been registered in winter rye Siverske, while the lowest – in Intensivne 99.

Benghal Dayflower (Commelina benghalensis) Seed Viability in Soil

Benghal dayflower is an exotic weed species in the United States that is a challenge to manage in agricultural fields. Research was conducted in North Carolina, Georgia, and Florida to evaluate the longevity of buried Benghal dayflower seeds. Seeds were buried in the field for 2 to 60 mo at a depth of 20 cm in mesh bags containing soil native to each area. In North Carolina, decline of Benghal dayflower seed viability was described by a sigmoidal regression model, with seed size having no effect on viability. Seed viability at the initiation of the study was 81%. After burial, viability declined to 51% after 24 mo, 27% after 36 mo, and < 1% after 42 mo. In Georgia, initial seed viability averaged 86% and declined to 63 and 33% at 12 and 24 mo, respectively. Burial of 36 mo or longer reduced seed viability to < 2%. The relationship between Benghal dayflower seed viability and burial time was described by a sigmoidal regression model. In Florida, there was greater variability in Benghal dayflower seed viability than there was at the other locations. Seed viability at the first sampling date after 2 mo of burial was 63%. Although there were fluctuations during the first 24 mo, the regression model indicated approximately 60% of seed remained viable. After 34 mo of burial, seed viability was reduced to 46% and then rapidly fell to 7% at 39 mo, which was consistent with the decrease in seed viability at the other locations. Although there is a physical dormancy imposed by the seed coat of Benghal dayflower, which has been detected in previous studies, it appears that a decline in buried seed viability to minimal levels occurs within 39 to 48 mo in the southeastern United States, suggesting that management programs must prevent seed production for at least four growing seasons to severely reduce the Benghal dayflower soil seedbank.

Analysis of ancient DNA from in vitro grown tissues of 1600-year-old seeds revealed the species as Anagyris foetida

AbstractSeven ancient seeds, about 1600 years old, were found during an archaeological excavation in Asar Island which is located in south-western Turkey. These seeds were subjected to germination, in vitro callus induction and molecular characterization experiments to test the viability and plant origin of the seeds. Six of the seven seeds had viable seed components (such as cotyledons) and produced callus tissue in Murashige and Skoog medium supplemented with 2 mg l− 1 6-benzylamino purine (BAP), 0.2 mg l− 1 1-naphthaleneacetic acid (NAA), 20 g l− 1 sucrose, 2 mg l− 1 glycine and 7 g l− 1 agar, but the calli from these seeds failed to yield adventitious shoots. DNA samples from callus tissues produced by ancient seeds in vitro were of good quality. The internal transcribed spacer (ITS) region in nuclear DNA (nDNA) of ancient seeds was amplified successfully. The sequences from amplified ITS DNA products of six ancient seeds indicated that their ITS sequences matched those of Anagyris foetida after subjecting them to BLAST searches in international sequence databases (NCBI). A. foetida is a relict species endemic to the Mediterranean region and used as a herbal medicine. We believe that seed characteristics such as the very hard, extremely smooth and shiny testa, toxic anagyrine alkaloid content and their storage in a pot further improved the longevity of these ancient seeds.

Burial increases seed longevity of two Artemisia tridentata (Asteraceae) subspecies

Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an active role in postfire recovery of the foundation shrub Artemisia tridentata, yet conditions under which seeds persist are largely unknown. We investigated seed longevity of two Artemisia tridentata subspecies in situ by retrieving seed bags that were placed at varying depths over a 2 yr period. We also sampled naturally dispersed seeds in litter and soil immediately after seed dispersal and before flowering in subsequent seasons to estimate seed persistence. After 24 mo, seeds buried at least 3 cm below the soil surface retained 30-40% viability whereas viability of seeds on the surface and under litter declined to 0 and < 11%, respectively. The density of naturally dispersed seeds in the seed bank was highly heterogeneous both spatially and temporally, and attrition varied significantly by region. Our study suggests that Artemisia tridentata has the potential to form a short-term soil seed bank that persists longer than has been commonly assumed, and that burial is necessary for seed longevity. Use of seeding techniques that promote burial of some seeds to aid in formation of a soil seed bank may increase restoration potential.

Coffee seed conservation biology: Fundamental aspects and practical implications. A review

Since the early 1990s, the coffee seed has been designated by several international laboratories as the model system for studying the physiology of seeds of the "intermediate" category. In contrast to orthodox seeds, longevity of which increases when they are dehydrated and stored at low temperature, intermediate seeds are only partially tolerant to desiccation and low temperatures. In the narrow ranges of water contents and temperatures which can thus be used, the longevity of intermediate seeds remains very short, which constitutes a major limitation for the conservation of the biodiversity of these species. The development of new analytical chemistry techniques made it possible to demonstrate that the poor longevity of coffee seeds was associated with several types of cellular damage : neutral lipid hydrolysis leading to the accumulation of free fatty acids which destabilize membranes, selective loss of a class of phospholipids, loss and oxidation of the two major hydrophilic antioxidants, ascorbic acid and glutathione. Thanks to the knowledge gained on the processes involved in coffee seed ageing, we propose for the first time in this paper highly accurate technical recommendations for the preparation and the short-term storage of seed lots. Meanwhile, through biophysical approaches including differential scanning calorimetry, the understanding of the mechanisms involved in coffee seed tolerance to ultra-low temperature exposure has significantly progressed. Based on this knowledge, a very effective cryopreservation technique has been developed for coffee seeds, facilitating the long-term conservation of Coffea genetic resources.

Sensibilidade à dessecação e aoarmazenamento em sementes de Eugenia pyriformis Cambess. (uvaia)

Objetivou-se com este trabalho avaliar a sensibilidade à dessecação e a longevidade durante o armazenamento de sementes de Eugenia pyriformis Cambess. (uvaia). Os frutos utilizados foram coletados em matrizes localizadas na cidade de Amambai-MS. Para o estudo da sensibilidade à dessecação, foi utilizado o protocolo baseado na redução do nível de hidratação das sementes a cada cinco pontos percentuais, obtendo-se sementes com teores de água de 45; 40; 30; 25; 20; 15; 10 e 5%. Para estudar a longevidade das sementes durante o armazenamento, foram testadas as condições de câmara fria e seca (16±1Cº/40% UR), geladeira (5±1Cº) e freezer (-18±1ºC) durante 30 dias, e as sementes que não foram submetidas ao armazenamento constituíram o tratamento-controle. A semeadura foi realizada entre areia a 20/30ºC com 10h de luz/14h de escuro em B.O.D. As sementes de uvaia são sensíveis à dessecação e não toleraram a secagem a 5% de teor de água. As sementes recém-beneficiadas apresentaram germinação de aproximadamente 77% e com a secagem até 5% houve a redução para 15% de germinação. A diminuição do teor de água provocou a redução da massa fresca, comprimento de raiz primária, hipocótilo e total de plântulas e tempo médio de germinação. As condições de armazenamento sob temperaturas baixas e a secagem reduziram a germinação das sementes, indicando assim o comportamento recalcitrante das sementes de uvaia.

The invasive status of wild barley (Hordeum spontaneum Koch) in Iranian flora

The success of a weed’s biological pathway is dependent on several factors including the mechanism(s) of dispersal, longevity of seeds in the soil seed bank, adaptation to varying environmental conditions and, competitive and reproductive abilities. In Near East barley, some races can be identified as wild but in other races wild and weed forms are confounded. Wild barley has wider distribution than the wild wheat and is spread over a wide area in the East Mediterranean basin and West Asiatic countries. In the Fertile Crescent countries, Hordeum spontaneum occupies a whole array of secondary man-made habitats. Invasive weeds possess a variety of characteristics that enable them to disperse rapidly into new areas. A variety of both aboveground and belowground plant traits can be used for identifying invasive species. Wild barley has some considerable traits including high genetic variation, high allelopathic potential, high relative growth rate, root characteristics, high competitive abilities and, became an invasive species in many habitats of Iran. Further studies are essential to evaluate the other mechanism(s) of invasiveness of wild barley in alien environment. Key words: Wild barley, Hordeum spontaneum, habitat, distribution, invasive weed.

Effects of resin tapping and tree size on the purity, germination and storage behavior of Boswellia papyrifera (Del.) Hochst. seeds from Metema District, northwestern Ethiopia

Boswellia papyrifera (Del.) Hochst. is one of the tree species in dry woodlands of Ethiopia that provides several goods and services. Despite its wide economic and ecological importance, its area coverage is dwindling from time to time, and its natural regeneration is hampered. Hence, long-term prospect for a sustained supply of the goods and services from the species is becoming questionable. The objectives of this study were to investigate: (i) the effect of resin tapping and tree size (DBH) on seed susceptibility to insect attack and the production of viable seeds; and (ii) seed longevity and germination ecology of the seeds of B. papyrifera. We collected seeds from tapped and untapped B. papyrifera stands at Lemlem Terara in Metema District, northwestern Ethiopia. The result showed that both tapped and untapped stands produced comparable insect attacked seeds (tapped stands=16.6%; untapped stands=15.8%). Untapped trees yielded significantly (P<0.0001) higher viable seeds (59%) than continuously tapped trees (49.3%), and trees with medium size (20cm DBH) provided more viable seeds than bigger (30cm DBH) and younger trees (10cm DBH). Longevity of B. papyrifera seeds indicated significant difference in viability under three different temperature regimes (5, 15 and 21°C), three storage periods (6, 9 and 12months) and two tapping regimes (tapped and untapped populations). Fire that produced temperatures above 100°C was lethal to the seeds as it caused complete loss of germinability regardless of exposure time. However, heat with temperatures less than 100°C did not cause loss of germinability even after an hour of exposure. We also found that light conditions had no significant impact on the germination percentage. In general, viability of the seeds was affected by tapping and tree size but not by storage conditions and period, modest temperature and light conditions.

Physiological and biochemical changes of angelica seeds during storage with different moisture contents

To study the physiological and biochemical changes during storage of angelica seeds with different moisture contents. The dynamic changes of percentage and index of seeds germination, relative conductivity, superoxide dismutase (SOD) activity, contents of soluble sugar and protein were determined at an interval of every two months. Under the conditions stored in sealed paper cups at 15 degrees C for 10 months, the germination percentage of angelica seeds with 2.85% of moisture content was kept above 85%. With moisture content reducing, the increase rate of relative conductivity decreased, the down trend of SOD activity and protein content were weakened, and soluble sugar content kept stable. In cool conditions, a modest low moisture content of seeds can be beneficial to prolong the longevity of angelica seeds, while high moisture content will accelerate the deterioration process of the seeds.

Application of cryoprotectants to improve low temperature storage survival of orchid seeds

To improve the longevity of orchid seeds during long-term frozen storage, five cryoprotectants: glucose, honey, meso-inositol, mannitol and skimmed milk were used to simply treat the seeds of twelve orchid species. The most effective cryoprotectant was 5% (w/v) meso-inositol, followed by 7.5% (w/v) mannitol and 7.5% (w/v) glucose. When the seeds of Dendrobium crystallinum Rchb.f., Dendrobium virgineum Rchb.f., and Vanda Miss Joaquim, were coated with meso-inositol and preserved at −70°C for one year, the germination percentage of the coated seeds was 50.7, 31.5 and 8.6%, respectively. After further storage for two to five years, the germination percentage remained stable at averages of 34.5, 17.4 and 4.1%, respectively and there was no effect on seedling development. However, the seeds coated with meso-inositol lost viability after being kept at 4°C and −20°C for one and two years, respectively. Success in using meso-inositol as a non-toxic cryoprotectant to extend the orchid seed viability would help to advance the knowledge of orchid seed bank development.

Edaphic factors influence the longevity of seeds in the soil

A thorough understanding of the rate of depletion of ungerminated seeds in soil is necessary to understand and model the population dynamics of many plant species. To assess how edaphic conditions influence seed survival over time a long-term field study was set up. Mesh bags of seeds of 12 species were buried under 12 contrasting semi-natural and grassland habitats and retrieved at intervals over 10 years. Seed survival and viability were assessed through germination trials and chemical staining. There were clear differences in the rate of depletion of ungerminated seed between species and also differences in the variability of this measure between habitats. Seed survival was longer in soils with a higher pH, lower moisture content and lower soil C:N. Soil characteristics need to be taken into account within studies of plant populations that depend on regeneration from seed, particularly for species where seed survival is sensitive to edaphic conditions. Ignoring this influence of the dynamics of seeds under different soil conditions may have a serious impact on the success of population modelling.

Longevity and germination ecology of seeds of endemic Cactaceae species from high-altitude sites in south-eastern Brazil

AbstractThe influence of light and temperature on germination behaviour and the longevity of seeds were evaluated in four taxa of the genusArthrocereus(Cactaceae). Germination experiments were conducted at six constant temperatures with a 12-h photoperiod and in continuous darkness. Forin situstorage tests, the seeds were buried in the soil where the species naturally occur, and germination experiments were performed for 14 months. Seeds were also stored dry at room temperature in the laboratory for 12 months. The results indicated that, in spite of the variations between the four taxa studied, there is a consistent pattern in their germination behaviour. The seeds are small, with an absolute requirement of light for germination. In the presence of light, we obtained high germinability at temperatures between 20 and 30°C and low germination percentages at 10, 15 and 35°C. This behaviour may represent an adaptive mechanism during seasons when environmental conditions in open rocky fields are not favourable for seedling survival. In general, germination was relatively slow, which would favour establishment during the rainy season. Dry storage did not significantly alter seed germination behaviour, and buried seeds, likewise, remained viable and retained high germination percentages. We can therefore infer that the seeds of the species studied here are able to form persistent soil seed-banks. All studied species are threatened with extinction, so their ability to form soil seed-banks, together with the possibility ofex situseed preservation, will possibly give support for future conservation efforts.

Comparison of Aging Characteristics and Longevity of Wheat Seeds in Vacuum and Non-vacuum Packages Storage in Mid-term Low-temperature Genebank

Comparison of Aging Characteristics and Longevity of Wheat Seeds in Vacuum and Non-vacuum Packages Storage in Mid-term Low-temperature Genebank

Common and distinct responses in phytohormone and vitamin E changes during seed burial and dormancy in Xyris bialata and X. peregrina

Temperature and humidity are the main factors influencing seed viability, dormancy and longevity of buried seeds. Unfortunately, very little is known about such processes in species of tropical regions, where temperature does not show major seasonal variations. The extent to which germination capacity, phytohormones and vitamin E levels were altered after burial of seeds of Xyris bialata and X. peregrina (Xyridaceae), two species endemic to rupestrian fields of Brazil, was examined. After 2 months of burial, seed germination capacity remained constant, which is associated with decreases in ABA and IAA content in both species. During this period, zeatin levels also decreased in X. bialata, but not in X. peregrina, the latter showing much lower levels of ABA. During the summer (rainy season), seeds of both species experienced a progressive, but severe, decrease in germination capacity, which reversed at the end of the winter (dry season), thus suggesting secondary dormancy. This dormancy appeared to be caused by drastic decreases in GAs, rather than increases in ABA. Levels of GA(4) decreased to non-detectable values during dormancy in both species. Furthermore, zeatin levels decreased in X. bialata but not in X.peregrina during this period. Both species accumulated γ-tocopherol as the major vitamin E form, and levels of this antioxidant remained constant or even increased during seed burial; however, X. bialata seeds showed a significant decrease in α-tocopherol during seed burial and dormancy. It is concluded that in X. peregrina and X. bialata, (i) burial causes significant changes in the phytohormone levels of seeds; (ii) secondary dormancy is induced in seeds; (iii) a GA(4) decrease, rather than an ABA increase, seems to be involved in the induction of secondary dormancy; and (iv) reductions in α-tocopherol in buried seeds are not necessarily indicative of reduced germination capacity.

EQUAÇÃO DE LONGEVIDADE PARA SEMENTES DE CAFÉ (Coffea arabica L.)

Objetivou-se equacionar a longevidade de sementes de café usando o Modelo de Probit. Valores obtidos da literatura de curvas de sobrevivência de sementes de café, armazenadas sob diferentes temperaturas e teores de água, foram transformados em probit e utilizados em regressões lineares e não lineares para determinação dos coeficientes de equações de viabilidade. Os resultados das análises permitiram concluir que: um modelo quadrático apresentou ajuste adequado, com desvio padrão de 8,9% de germinação, para equacionar a perda de germinação de sementes de café armazenadas, enquanto o modelo tradicional apresentou desvio padrão de 15,1% de germinação; a regressão não linear, comparada com a regressão linear múltipla, resultou em menores 1,5 a 2,2 vezes desvios padrão na determinação dos coeficientes da equação do desvio padrão da frequência de distribuição das sementes mortas durante o período de armazenamento (σ); e as sementes de café não apresentaram comportamento de ortodoxas, indicado pelas variações não lineares do logaritmo de σ em função das variações do logaritmo do teor de água das sementes.

Viability equation to determine the longevity of fungicide-treated seeds of wheat stored in a conventional warehouse

The objective of this research was to determine the deterioration rate of BRS 208 and CD 104 wheat cultivar seeds, treated with fungicides, by applying the viability equation. Seeds were stored in conventional warehouses in Maua da Serra and Londrina, in the State of Parana, Brazil. Four seed lots were divided into four replications, half being treated with Carboxin + Thiran and the other half taken as controls, without treatment, and these were stored for 300 days. The germination data were transformed into probit, and a straight line was adjusted between 0 and 30 days. The treated seed lot of cv. BRS 208 stored in Londrina gave seed deterioration rates varying from 0.8.10-3 to 1.3.10-3, not differing from the values given for the similar lot stored in Maua da Serra, of 0.9.10-3. The deterioration rates of the treated seed of cv. CD 104 were 1.2.10-3 in Maua da Serra and 2.0.10-3 in Londrina, which are greater than those values given for untreated seeds of 0.4.10-3 and 0.5.10-3. This model provides an effective approach to predict the untreated and treated seed longevity of wheat for the purpose of managing seeds