Long-term Storage Of Seeds Research Articles

Effect of desiccation damage on the seed viability of Hydnocarpus alpina Wight. of Western Ghats

Hydnocarpus alpina Wight is an evergreen endangered medicinal tree species of Western Ghats. Several local names are available based on the distribution among the state in India that is Torathi (Kannada), Maravetti/Marotti (Malayalam), Attuchankalai (Tamil), Kastel (Hindi). Hydnocarpus alpina has very appreciated value in various medicinal properties like anti-larvicidal, anti-feedant, antimicrobial etc. due to the presence of significant chemical constituents. The seeds of this tree species are characterized with high moisture content and are intolerant to desiccation. They are under recalcitrant type seeds.Fully mature H. alpina seeds have 20% moisture content on harvest and recorded 80% germination. After 2 weeks of desiccation at open laboratory conditions (28±2 °C and 65% RH) their moisture content and percentage of germination decreased to 10.2% and 20 % respectively. Complete loss of viability occurred at 10% moisture level. This clearly indicates the recalcitrant nature of seeds. Different biochemical parameters such as lipid peroxidation, leachate conductivity, assay of free radical scavenging enzymes, analysis of primary metabolites like total soluble sugars, starch, total proteins, amino acids, lipids, phenols etc. were recorded for finding the biochemical basis of desiccation induced damage on seed viability. The results of the study reveals the metabolic disturbances associated with the desiccation of seeds and such parameters can be considered as markers for assessing the seed viability. Hence, safest low moisture content for the long term storage of seeds can be identified for the conservation of this endangered species of Western Ghats.

Determination of Hydrogen Peroxide Content and Antioxidant Enzyme Activities in Safflower (Carthamus tinctorius L.) Seeds After Accelerated Aging Test

Safflower is an important oleiferous crop species in the world. Aging tests are used to simulate cell damage occurring during the long term storage of seeds. In the present study, accelerated aging (AA) test was employed to investigate response of antioxidant enzymes in safflower. Four genotypes of safflower, previously classified as aging resistant (Bayer-6 and Bayer-12) and sensitive (Olas and Linas) based on AA test, were used as seed materials and AA treatments at 43 °C consisted of 5 different times (0, 48, 72, 96 and 120 h). Variance analysis were used and means were separated according to significance levels, and correlations were calculated between hydrogen peroxide (H2O2) content, superoxide dismutase (SOD) and catalase (CAT) activities. The H2O2 content, CAT, SOD and peroxidase (POD) activities were measured in control and AA treated seeds. Genotype, time and genotype x time interactions were all significant. While H2O2 content and SOD activity increased with AA time, CAT activity decreased in all genotypes throughout the experiment. POD did not show regular increase or decrease, its activity was specific to genotypes and time. Correlations between CAT activity and H2O2 content were significant negative for all genotypes, but between SOD activity and H2O2 content was positively correlated in AA treated seeds.

Enhancing seed conservation in rural communities of Guatemala by implementing the dry chain concept

Seed conservation in rural communities of low- and middle-income countries located in tropical areas is particularly problematic, due to high relative humidity that promotes insect and fungal infestations and leads to rapid losses in seed viability. Seed conservation in those areas is affected by unreliable power supplies that do not allow the use of dehumidifying and refrigeration systems recommended for the long-term storage of seeds. We tested the dry chain, i.e., initial seed drying with a reusable desiccant in the form of zeolite beads followed by seed conservation in hermetic containers, in rural communities of Guatemala (Huehuetenango Department). In this region, a network of community seed reserves (CSRs) has been established to provide a safety backup for seed and to conserve local agrobiodiversity. Using a local maize variety in three communities, we compared the dry chain with the seed conservation methodology employed in the CSRs (i.e., undried seeds in hermetic flasks) as well as with seed conservation in open storage, both in the local CSR and in a farmer’s granary. Seed conserved using the dry chain treatment maintained very high seed viability (> 80%) throughout the whole experiment (6 months) and reduced fungal and insect infestations (< 3%). In the other treatments, the viability declined significantly to an average of 52% non-viable and 19% infested seeds after 6 months of storage. The dry chain was demonstrated to be an excellent solution for enhancing seed conservation in biodiversity hotspots of tropical areas as well as for improving seed security for farmers.

Lost in Translation: Physiological Roles of Stored mRNAs in Seed Germination

Seeds characteristics such as germination ability, dormancy, and storability/longevity are important traits in agriculture, and various genes have been identified that are involved in its regulation at the transcriptional and post-transcriptional level. A particularity of mature dry seeds is a special mechanism that allows them to accumulate more than 10,000 mRNAs during seed maturation and use them as templates to synthesize proteins during germination. Some of these stored mRNAs are also referred to as long-lived mRNAs because they remain translatable even after seeds have been exposed to long-term stressful conditions. Mature seeds can germinate even in the presence of transcriptional inhibitors, and this ability is acquired in mid-seed development. The type of mRNA that accumulates in seeds is affected by the plant hormone abscisic acid and environmental factors, and most of them accumulate in seeds in the form of monosomes. Release of seed dormancy during after-ripening involves the selective oxidation of stored mRNAs and this prevents translation of proteins that function in the suppression of germination after imbibition. Non-selective oxidation and degradation of stored mRNAs occurs during long-term storage of seeds so that the quality of stored RNAs is linked to the degree of seed deterioration. After seed imbibition, a population of stored mRNAs are selectively loaded into polysomes and the mRNAs, involved in processes such as redox, glycolysis, and protein synthesis, are actively translated for germination.

Features of propagation by seeds of rare and endangered plant species in culture

The article is devoted to the conservation of rare and endangered species in a culture The problems and features of reproduction by seeds of these species were been considered. The stages were been distinguished – preparatory (informational), seed collection, drying, peeling, storage, germination, genetic identification. Approaches to seed collection and storage were been presented. It is proposed to use a refrigeration chamber (+ 4 ° C) for long-term storage of seeds.

Embryo Rescue of Aged Cucurbita pepo Seeds Using Squash Rescue Medium

Plant seed is both an important food source and an indispensable propagation material for many cultivated crop species. The ideal conditions required for long-term storage of seeds are expensive, exacting, and not always tenable, particularly for small breeding programs. In most plant species, viability is significantly reduced in old, sub-optimally stored seeds due to depleted energy reserves and biochemical degradation.

Proteome analysis of dormancy-released seeds of Fraxinus mandshurica Rupr. in response to re-dehydration under different conditions.

Desiccation tolerance is the ability of orthodox seeds to achieve equilibrium with atmospheric relative humidity and to survive in this state. Understanding how orthodox seeds respond to dehydration is important for improving quality and long-term storage of seeds under low temperature and drought stress conditions. Long-term storage of seeds is an artificial situation, because in most natural situations a seed that has been shed may not remain in a desiccated state for very long, and if dormant it may undergo repeated cycles of hydration. Different types of seeds are differentially sensitive to desiccation and this directly affects long-term storage. For these reasons, many researchers are investigating loss of desiccation tolerance during orthodox seed development to understand how it is acquired. In this study, the orthodox seed proteome response of Fraxinus mandshurica Rupr. to dehydration (to a relative water content of 10%, which mimics seed dehydration) was investigated under four different conditions viz. 20 °C; 20 °C with silica gel; 1 °C; and 1 °C after pretreatment with Ca2+. Proteins from seeds dehydrated under different conditions were extracted and separated by two-dimensional difference gel electrophoresis (2D-DIGE). A total of 2919 protein spots were detected, and high-resolution 2D-DIGE indicated there were 27 differentially expressed. Seven of these were identified using MALDI TOF/TOF mass spectrometry. Inferences from bioinformatics annotations of these proteins established the possible involvement of detoxifying enzymes, transport proteins, and nucleotide metabolism enzymes in response to dehydration. Of the seven differentially abundant proteins, the amounts of six were down-regulated and one was up-regulated. Also, a putative acyl-coenzyme A oxidase of the glyoxylate cycle increased in abundance. In particular, the presence of kinesin-1, a protein important for regulation and cargo interaction, was up-regulated in seeds exposed to low temperature dehydration. Kinesin-1 is present in all major lineages, but it is rarely detected in seed desiccation tolerance of woody species. These observations provide new insight into the proteome of seeds in deep dormancy under different desiccation conditions.

Preservation of the gene pool of plants under permafrost conditions: State, advantages, and prospects

The effect of long-term storage of seeds of three leguminous species (Pisum sativum, Lens culinaris, and Cicer arietinum) on physiological (germination rate) and cytological (mitotic index) parameters of the seeds and seedlings derived therefrom has been studied. It has been found that, after nearly 35 years of storage in permafrost (temperature from −5.5 to −6.0°C) without replanting, the germination of seeds of varieties of the species studied remains at the same or a slightly lower level than in reference samples (seeds of the same varieties harvested in 2007–2009), without a significant difference in root growth rate. The observed number of chromosomal aberrations in root meristem cells does not increase except for in the case of P. sativum cv. Latores and L. culinaris cv. k-2330, and in these cases neither the laboratory germination rate nor the rates of growth processes decrease. Thus, long-term storage of seeds under permafrost conditions favors the preservation of their viability (germination ability) and can be suggested as a promising method of seed storage.

27. Physiological–biochemical characteristics of Pisum sativum seedlings after long-term storage of seeds in the permafrost conditions

Loss of seed viability cannot be prevented, this process is irreversible, but it is quite possible to slow the process down if the necessary storage conditions are created. In this context it is very important to develop and use methods of long-term storage of seeds. It is known that some of the main factors affecting the duration of seed storage are temperature and humidity (moisture content). Long-term storage of plant material in the form of seeds is one of the most popular and effective methods to the preservation of most species of the world. Creation of seed banks has significant advantages over other methods for plant preservation ex-situ: storage of a large number of samples is simplified, space saving and has relatively low labour costs. The material for the study were the seeds and seedlings of three cultivars (“Imposant”, “Latores” and “Rosol”) of pea (Pisum sativum L.). Seeds of 1977 harvest were laid down in long-term storage in permafrost in the underground laboratory of the Institute of Permafrost, SB RAS (Yakutsk) to a depth of 12 m. Storage for 34 years was carried out in hermetical glass vessels of 100 cm3 at a constant temperature of −6.5 ± 0.5 °C. Before laying down the seeds for storage their moisture content did not exceed 5–7%. As a control seeds and seedlings were used from the same cultivars of P. sativum 2007–2009 from the collection of N. I. Vavilov Research Institute of Plant Industry. It is shown that after 34 years of low temperature (−6.5 ± 0.5 °C) storage of three cultivars seeds (“Imposant”, “Latores” and “Rosol”) of pea (Pisum sativum L.) under permafrost conditions, the physiological parameters of seed and seedlings (germination, root length, dry weight), as well as the mitotic activity of roots cells did not differ from control. However, a small increase in the number of abnormal ana-telophase of mitosis in root meristem cells of cultivars “Imposant” and “Latores” was shown in comparison to the control. After long-term storage of three P. sativum cultivar seeds balanced work prooxidant-antioxidant systems in a simple compensation regime was observed in the tissues of seedlings. It was noted that long-term storage of seed cultivars “Imposant” and “Latores” caused a decrease of photosynthetic pigment content in the seedling tissue that along with a small increase of the number of abnormal mitoses may be evidence of the beginning of the process of aging of seeds. In general, it is shown that long-term storage of seeds of three cultivars of P. sativum in permafrost conditions enabled the preservation of their viability and can be offered as prospective way to store seeds.

The Role of Red Squirrels (Tamiasciurus Hudsonicus) in Shaping Spatial Patterns of Serotiny in Lodgepole Pine (Pinus Contorta) Forests

Understanding the effects of individual species on community- and ecosystem-level processes is of critical importance in ecology. Recent work has demonstrated that variation in genetically controlled traits within foundation species can have large implications for ecosystem processes. Identifying these traits and the selective pressures on them is crucial in understanding how ecosystems are structured and how the systems will respond to disturbance. Serotiny, the long-term storage of seeds in the canopy, is thought to be an adaptation to stand replacing fire. Seeds from serotinous plants are released following a fire, and the proportion of serotinous trees determines sapling density following a fire. The effects of serotiny are not limited to the serotinous species, as sapling density is an important determinant of plant community structure and ecosystem processes (including primary productivity and nutrient cycling). Seed predation may select against serotiny, however, no studies have addressed how the relative strengths of selection from fire and seed predation combine to produce the spatial pattern of serotiny on the landscape. Here, we report on an ongoing study of the effects of selection from seed predation in lodgepole pine (Pinus contorta), a serotinous North American conifer. Red squirrels are negatively associated with serotiny at broad geographic scales, and may select against the serotinous trait. This project examined the correlation between red squirrel density and the frequency of serotiny in lodgepole pine forests and the mechanisms underlying potential selection against serotiny by red squirrels. Specifically, we tested whether this correlation was present at landscape scales, whether the fitness of serotinous trees was reduced in the presence of red squirrels, and what factors controlled the density of red squirrels. Preliminary results indicate that serotiny and squirrel density is negatively correlated, but only at low elevations. In the presence of squirrels, we observed significantly lower cone survival in serotinous trees, suggesting reduced fitness. Squirrel density was strongly affected by several measures of forest structure, including species composition, overhead canopy cover, and tree size (mean DBH).

Long term storage of seeds of some riparian trees (II) : result after 8 years

Long term storage of seeds of some riparian trees (II) : result after 8 years

Population genetics and conservation of the critically endangeredClematis acerifolia(Ranunculaceae)

Allozyme electrophoresis was used to evaluate the levels of genetic diversity and population genetic structure of the critically endangered Clematis acerifolia Maximowicz (Ranunculaceae), a narrow endemic species in China. On the basis of variation at 19 putative loci in nine populations covering the entire distribution of this species, low values of genetic diversity were detected (P = 20.5%, A = 1.27, and He= 0.072). A significant deficiency of heterozygotes was found in all populations. Most loci showed deviations from the Hardy–Weinberg equilibrium, probably as a result of population genetic structuring. The high genetic divergence among populations (FST= 0.273) can be interpreted as an effect of the extinction of local populations and genetic drift within extant populations, and has probably been enhanced by habitat fragmentation in recent decades. Threats to this species are mainly anthropogenic (road works, construction of holiday resorts, and extraction activities), although stochastic risks cannot be ignored. Therefore, to preserve extant genetic variation of C. acerifolia, in situ strategies, such as the preservation of its habitat or at least the most diverse populations, and ex situ measures, such as the collection and long-term storage of seeds, should be adopted.

Long term storage of seeds of some riparian trees

Long term storage of seeds of some riparian trees

Population genetics and conservation priorities for the critically endangered island endemic Delphinium pentagynum subsp. formenteranum (Ranunculaceae)

Isozyme electrophoresis was used to evaluate levels of genetic diversity and population genetic structure of the critically endangered (CR) perennial larkspur, Delphinium pentagynum subsp. formen- teranum (Ranunculaceae), endemic to the island of Formentera (Balearic Islands, Spain). There is only one known population for this taxon, containing only 480 individuals. Moderate values of diversity were detected (P 5 40.7%, A 5 1.6 and H 5 0.180), within the range observed in other surveyed larkspurs, e but higher than most island endemics. Moderate levels of inbreeding were detected, probably as a consequence of the population's genetic structuring (biparental inbreeding). Threats to this taxon are mainly anthropogenic (fires, grazing, pathway works, and building pressures), although given that only one population exists, stochastic risks cannot be ignored. Conservation of D. pentagynum subsp. formenteranum requires in situ strategies, such as implementing a monitoring program and establishing a 'botanical reserve', and ex situ strategies, such as collection and long-term storage of seeds.

Sequential Methods for Monitoring Declining Quality, with Application to the Long-Term Storage of Seeds

SUMMARY The results in this paper were motivated by the problem of monitoring the quality of seeds being stored for long periods under conditions of low temperature and low humidity. Under the assumption of a simple and smooth form of deterioration, a unified procedure is developed which specifies both when and how the seed lot should be inspected. Limits on the probability of reaching a prespecified poor quality are set. The theory is presented in a general form, in the expectation that it will be useful in other applications. Specific details for implementation in seed banks are given, and computer simulations are used to confirm the validity of approximate theory. The quality of some resource is declining with the passage of time from an initially high value, until eventually an unacceptable standard will be reached. Determination of the quality at any particular time can be achieved by inspection, but inspections are expensive and subject to error. This paper addresses two related issues: when to make the inspections, and how to decide when the unacceptable standard has been reached. The methods that will be used are those of hypothesis testing, and not decision theory. It will be assumed that the decline in quality is smooth, and can be represented by a simple model. This research has been motivated by a particular practical context. Seed banks exist to conserve genetic resources through the long-term storage of seeds. Each accession, within the bank is a collection of several thousand seeds of a particular strain stored under homogenous conditions of low temperature and low humidity. Initially the accession will have a high viability: a high proportion of the seeds would germinate if planted. The viability will deteriorate slowly over time until an unacceptably low value is reached. The potential storage life for many plant varieties will be 100 years or more. Inspections take the form of germination tests conducted on samples drawn from the accession. These inspections are time-consuming and expensive in the sense that they deplete the very accessions that are to be conserved. If the viability is found to be unacceptably low, then the stock will be regenerated: some of the seeds will be planted, the crop will be harvested, and new seeds will be collected and stored in place of the old accession. The operation of seed banks is described in Ellis, Tong, and Roberts (1985) and sequential designs for a single inspection are discussed by Whitehead (1981) and Ellis and Whitehead (1987). The theory will be developed in some generality in the hope that other applications for the procedure might be found. It is likely that analogous problems arise in other storage situations. Ecological or medical monitoring might provide other examples.