Seed Storage Behaviour Research Articles

Influence of maturity stage on physical and chemical characteristics of fruit and physiological quality of seeds of Physalis angulata L.

Physalis angulata L. is an annual herb of the Solanaceae family, known in Brazil as camapu. Its fruits are widely eaten due to their high nutritional content and various plant parts are also used for medicinal purposes plant. The objective of this study was to evaluate the physiological maturity of P. angulata seeds during fruit development and maturation, as well as to identify the tolerance method for seed desiccation, contributing to the conservation of this species. Fruits and seeds were harvested at 15, 22, 29, 36 and 43 days after anthesis (DAA). The fruits were characterized regarding length, diameter, weight, total soluble solids, epicarp color, total number of seeds, and fresh seed weight. For determination of the seed physiological quality at different maturation times, freshly harvested seeds were dried at room conditions for 72 h and evaluated for water content, dry weight, germination percentage, germination index and seedling emergence. The desiccation tolerance was analyzed through fast and slow methods utilizing silica gel and saline solution of CaCl2. Significant increases were found in all physical and chemical traits of the fruits during development. Epicarp, nervure and calyx color can be used as good indicators of the degree of maturity, allowing identifying the best fruit harvest time. The seed physiological maturity of P. angulata was reached at 36 days after anthesis. The drying speed did not influence the seed germination percentage, germination index and vigor. P. angulata has orthodox seed storage behavior and can tolerate water content below 7%, which contributes to the maintenance of high viability (above 90%) for prolonged periods. Our findings can guide the conservation of P. angulata in seed banks and their use in breeding programs to obtain new hybrids.

Seed storage behavior of Musa balbisiana Colla, a wild progenitor of bananas and plantains - Implications for ex situ germplasm conservation

Musa balbisiana (BB) and M. acuminata (AA) are the two wild diploid progenitors of the cultivated, triploid, tetraploids bananas and plantains. Collection and safe conservation of crop wild relatives (CWR) has gained tremendous importance, as they are the reservoir of genes and traits required to combat climate change effects and the emerging biotic and abiotic stresses. The purpose of this study was to investigate seed storage behavior of M. balbisiana for devising and applying suitable strategies to conserve CWR of banana/plantain germplasm in gene banks, both for short-and long-term. Seeds (from mature fruits) of three accessions of M. balbisiana from Field Gene Bank of ICAR-NBPGR, New Delhi (EC653579) and natural populations from ICAR-NBPGR, Thrissur, Kerala (IC630992) and Mizoram University, Mizoram (IC633382) were augmented and desiccated to various moisture contents (MC at 5,10,15, 20 and 25 % on fresh weight basis). Fresh and desiccated seeds were stored at three temperatures (25, -20 and -196 °C) to assess freezing sensitivity. Whole seeds as well as excised zygotic embryos were cryopreserved at the optimized MC using simple air dehydration technique. For recovery, data on in vitro regeneration of zygotic embryos was recorded and analyzed statistically to determine optimal explant and conservation regime. Whole seeds in general were difficult to germinate whereas in vitro regeneration of zygotic embryos yielded high results (95 ± 5 %). Seeds were found to be desiccation tolerant (viable up to 5 % MC) and desiccated seeds (5–10 %) were insensitive to ultra-low temperature (-20 and -196 °C), without significant loss of viability and germination potential. High moisture content (15, 20 and 25 %) in seeds led to low regeneration potential (≤50 %) due to cold injury of cells at ultra-low temperatures (-20 and -196 °C). No significant differences were observed in regeneration of fresh and cryopreserved desiccated (5–10 % MC) excised embryos (90 ± 10 %). Our studies confirm that M. balbisiana seeds are ‘orthodox’ in storage behavior, and can be easily conserved for short-term at 25 °C, medium-term at -20 °C and long-term at -196 °C with 5–10 % MC. However, unlike other typical orthodox seeds, regeneration of conserved seeds is only feasible through zygotic embryo culture under in vitro conditions, as desiccated whole seeds fail to germinate using standard protocols. For cryobanking, whole seed or excised zygotic embryo cryopreservation is a feasible option for germplasm conservation of M. balbisiana.

Optimizing Germination of Melia volkensii Gürke after Storage of Seeds and Nuts in Different Storage Conditions

This study was conducted to understand the effect of nature of seed (nut or seed), storage conditions and storage time on the germination of Melia volkensii seeds. Two seed lots were stored for germination tests after storage of germination materials for 2, 4 and 6 months. Laboratory experimental setup involved three treatments: 1) some seeds were extracted while others were stored as nuts, 2) Storing the seeds in open and closed containers and 3) storage of the seeds in ambient temperature at 30 °C and cold storage at -20 °C. It was observed that the rate of germination and germination capacity of M. volkensii seeds increased with extension of storage time. Germination percen-tages were analyzed using R and SAS statistical software. Significance of variation for each month was tested using ANOVA at P≤ 0.05, and means were separated using fisher’s protected least significant difference test. Seed germination after 6 months of storage greatly improved for all storage treatments. The scientific procedure in the present study improved germination from 14 % when seeds were stored for 2 months in open containers at room temperature to 89% when nuts were stored in open containers in room temperature for 6 months. This study is vital in understanding seed storage behavior which is essential in planning and carrying out planting programmes; consequently, enhancing sus-tainable utilization of M. volkensii. Findings on appro-priate storage of nuts and seeds of M. volkensii will help develop a guideline on establishing a seed stock to ensure seed supply at all times even in times of irregular fruiting.

Effect of Desiccation and Storage Environment on Longevity of Ehretia cymosa Thonn. Seeds

Globally, forestry faces challenges in the availability of seeds due to limited knowledge on seed handling of various species. Forestry seeds are constantly being reviewed and classified as either recalcitrant, intermediate, or orthodox based on their storage behavior. It is essential to understand the tree seed storage behavior to maintain seed viability and thus minimize seed losses. There is scanty literature combining factors of seed moisture content (6%, 9%, 12%, 15%, and 20%), seed storage temperature (20oC, 5oC and -20oC), seed storage duration (1, 4, 9 and 12 months), and germination in different sites with varying environmental variables. Ehretia cymosa is important in the Afromontane forestry landscape as a medicinal, rehabilitation, and conservation species. This study conducted desiccation and storage studies and their influence on the viability of E. cymosa seeds. The study sought to determine the optimum conditions for the storage of Ehretia cymosa that maintains viability. This study observed that E. cymosa dried to seed moisture content of 6%, stored for 12 months at 20oC and sown in the laboratory had the highest germination performance (27.6 ± 3.18%) (p<0.05). This confirms that E. cymosa seeds exhibit orthodox storage behavior. The authors recommend longer storage studies (>12months) to determine the actual longevity of the seeds of this species. The significance of these results would be useful for foresters and farmers that would need to use this species for various purposes.

Collaborative exploration and collection of native plant genetic resources as assisted by agrobiodiversity fair

This article describes the agrobiodiversity fair aided exploration and collection expedition of native plant genetic resources in southern Lalitpur, jointly organized by the National Agriculture Genetic Resources Centre (NAGRC) and Group of Helping Hands (SAHAS) Nepal. In-district one-day agrobiodiversity fairs were organized in February and December month of 2019, altogether two times, and these agrobiodiversity fairs were used as a tool to explore plant genetic resources found in Bagmati and Mahankal Rural Municipalities of Lalitpur district. To collect these explored genetic resources during agrobiodiversity fairs, the joint field expedition, key informant survey, diversity rich farmers discussion was used as a collection tool. The present study explored, inventoried, collected and conserved 148 accessions of 44 crop species, the highest number (18 accessions) was of chayote followed by 10 accessions each of soybean, cowpea and maize and 9 accessions of common bean. Collections are generally new and unique. Many landraces, mostly from rice (13 landraces) were identified as extinct from the surveyed areas and few are under extinction mainly due to attraction of farmers to new high yielding varieties. The collected species with orthodox seeds were tested for germination ability and those that passed a minimum of 85% germination, were preserved in seedbank of NAGRC. NAGRC plans to characterize these accessions in the coming seasons depending upon the season of crop growing. The current expedition collected eight species for which mode of propagation is vegetative or those for which seed storage behavior falls under intermediate mode. NAGRC has been started expanding field genebank coverage using these accessions.

Drying and physiological quality of palheteira seeds (Clitoria fairchildiana R.A. Howard)

Knowledge about seed storage behavior is important to preserve plant species. Clitoria fairchildiana R.A.Howard is an endemic species with medicinal properties, it is used in the recovery of degraded land. The objective of this study is to evaluate the effect of drying on the physiological quality of C. fairchildiana seeds. Seeds were oven dried along with silica gel for 18 days and in intervals of 2 or 3 days, samples were removed to assess the seed moisture content. This was done in an oven at 105±3 oC for 24h, using four replicates with 10 seeds each. After undergoing the above-mentioned treatment, a sample of seeds was stored in the freezer (-18 ºC) for 3 months. Sowing was carried out in plastic trays in a sand and sawdust mixture (1:1), previously sterilized in hot water (100 oC) for two hours. Seeds were left to germinate in a laboratory with no temperature and relative humidity control. Germination tests were performed over 14 days with daily counts of the number of emerged seedlings. The percentage of seed germination, abnormal seedlings and dead seeds were obtained 14 days after sowing. The experimental design was completely randomized with four replications of 25 seeds. The reduction of seed moisture content from 18.5% to 5.6% affected physiological seed quality causing a reduction in the germination percentage and an increase in dead seeds and abnormal seedling percentage. C. fairchildiana seeds are classified as intermediate and they can be desiccated up to 8.6% with no reduction in physiology quality.

Effects of storage on seed germination and viability for three native tree species of Ecuador

Many forests restoration programs and efforts depend on seeds. Particularly in the Andes, further information regarding seed germination requirements and seed storage behavior is necessary. The aim of this study was to evaluate the effects of storage conditions on the germination percentage, the viability and the coefficient of velocity of germination for seeds of three native tree species (Cedrela montana, Weinmannia fagaroides and Oreocallis grandiflora). Under controlled conditions, the seeds were exposed to three levels of seed moisture content and storage temperatures (5 °C, 10 °C and room temperature at approx. 19 °C) for 3, 6 and 12 months. The results showed that at 3–6 months of seed storage under temperatures of 5 and 10 °C, the seeds had a high percentage of germination, viability and germination speed for C. montana and W. fagaroides compared to those stored at room temperature. At 12 months of storage, there was a marked reduction in seed germination in all treatments for both species. Furthermore, the seed germination and viability of O. grandiflora was not influenced by any of the above storage treatments. However, at the end of the experiment a slight decrease was observed, hence this species might be tolerant to medium- and long-term storage conditions. Though limited to just three co-occurring species, the study provided insight into the variability in responses to storage, with preliminary indications of appropriate storage conditions to maximize storability of seeds for restoration programs. Importantly, the study demonstrated the need for empirical testing of storage responses (temperature and duration) of seeds before subjecting untested species to a particular storage regime.

Embryo growth and seed germination of four taxa of Narcissus (section Pseudonarcissi) conserved under non‐recalcitrant seed conditions in germplasm banks

AbstractThe aim of this study was to determine the germinative ability of the seeds of four Narcissus taxa belonging to Section Pseudonarcissi after they had been conserved under the conditions of non‐recalcitrant seed storage protocols. For each taxon (N. alcaracensis, N. longispathus, N. radinganorum and N. pseudonarcissus subsp. munozii‐garmendiae), one seed lot was desiccated to 4% moisture content (MC) and stored under laboratory conditions (22°C, 40–50% relative humidity (RH), whereas another was dehydrated to 3% MC and stored at −10°C. The latter treatment simulated standard conservation conditions for non‐recalcitrant seeds. After 26 months, embryo growth and germination were evaluated. Seed responses were correlated with their MC upon dispersal. Seeds of N. alcaracensis, N. longispathus and N. radinganorum left to dry on the mother plant during maturation had 8–10% MC when dispersed, tolerated non‐recalcitrant seed conservation and germinated to >90% under the most favorable incubation conditions. Narcissus pseudonarcissus subsp. munozii‐garmendiae seeds did not undergo maturation drying and had 46.7% MC upon dispersal. They reached 100% germination after being desiccated to 4% and stored at 22°C, were not recalcitrant, but failed to germinate when stored at −10°C under non‐recalcitrant seed conservation conditions. Therefore, N. alcaracensis, N. longispathus and N. radinganorum seeds can be conserved under non‐recalcitrant seed conditions in germplasm banks, whereas those of N. pseudonarcissus subsp. munozii‐garmendiae are moderately recalcitrant. Seed storage behavior is influenced primarily by the extent of maturation drying of the seeds on the mother plant.

Seed development, germination, and storage behaviour of Syzygium maire (Myrtaceae), a threatened endemic New Zealand tree

ABSTRACT Syzygium maire is an endemic tree in New Zealand and classified as critically endangered. The in situ populations of this species are further threatened by the incursion of myrtle rust. The biology and ecology of S. maire have not been well documented and limited information on seed development, effective germination and seed storage behaviour of S. maire are hampering ex situ conservation and restoration. In this study, we investigated fruit and seed development on S. maire populations growing at four sites and in different seasons, and used short-term seed storage protocols to investigate the storage potential of harvested seeds. Fruit development took 8–11 months with three of the four identified stages occurring during the warmer spring and summer months. Embryos were found to be viable from stage two, but seedlings from final stage embryos were more robust. The moisture content of the fruit pulp varied between populations and within populations between seasons, but embryo moisture content remained more constant. S. maire seeds have high germinability when removed from the fruit pulp, and removal from the pulp is essential for germination. Seeds in fruits stored hydrated at 5°C remained viable for up to 12 weeks, although some germination was observed from eight weeks. This paper identifies optimal time for seed collection to ensure high quality seed for propagation and restoration while the short term storage provides an opportunity for further research into long term seed conservation through cryopreservation.

Characterization of fruit and seeds and identification of Tacca palmata seed storage behaviour using the 100-seed test method

Abstract. Wardani FF, Mimin. 2020. Characterization of fruit and seeds and identification of Tacca palmata seed storage behavior using the 100-seed test method. Pros Sem Nas Masy Biodiv Indon 6: 552-557. Tacca palmata is one of species from Dioscoreaceae which has potency as a medicinal and ornamental plant. Research on the characterization of T. palmata fruits and seeds is not known yet. Though seeds are one of the reproductive material for T. palmata. In addition, seed storage is required to maintain the availability of T. palmata seeds. Information about seed storage behavior is the most important thing to know the seed storage characteristic. Therefore, the aim of the study was to provide information about the characteristic of the fruit and seeds as a basis for determining the seed storage behavior of T. palmata. The method used was 100-seeds test method. A total of 100 seeds, divided into four groups i.e. 10 seeds for initial moisture content, 26 seeds for initial germination (13 seeds per replication), 32 seeds for desiccation (6 seeds for moisture content after desiccation and 26 seeds for germination after desiccation), and 32 seeds for storage with controlled humidity (6 seeds for moisture content after storage and 26 seeds for germination after storage). The results showed that the T. palmata fruits were round and bright red and its seeds had irregularly shaped and dark brown. The water content of T. palmata after desiccation was almost the same as the initial water content (14.58%), which was 14.55% and experienced an increase after being stored with controlled humidity (36.61%). T. palmata germinated with hypogeal type. The germination rate of T. palmata after desiccation was 38.46% and not significantly different from the initial germination rate (46.67%), whereas after being stored with controlled humidity, the germination rate was doubled, i.e., 76.92%. So it can be concluded that T. palmata seeds are tolerant of desiccation (orthodox).

Epicotyl morphophysiological dormancy and storage behaviour of seeds of Strychnos nux-vomica, Strychnos potatorum and Strychnos benthamii (Loganiaceae)

AbstractWe hypothesized that Strychnos nux-vomica and Strychnos potatorum in seasonal tropical ecosystems have dormant desiccation-tolerant seeds, while those of Strychnos benthamii growing in aseasonal wet habitats have non-dormant desiccation-sensitive seeds. Germination, imbibition, the effect of gibberellic acid on germination and changes in the embryo to seed length ratio (E:S) during incubation were determined for the three species. Seed storage behaviour was identified with the hundred seed test. Time taken for epicotyl emergence was recorded. Radicle emergence of S. nux-vomica, S. potatorum and S. benthamii at 25°C under light/dark conditions (12/12 h) was completed within 76, 49 and 11 d, respectively. S. nux-vomica and S. potatorum seeds incubated on GA3 germinated to a higher percentage than non-treated seeds. E:S of S. nux-vomica, S. potatorum and S. benthamii had increased by 38.2, 34.5 and 25.5%, respectively, at radicle emergence. Shoot emergence of S. nux-vomica, S. potatorum and S. benthamii was observed after 76, 74 and 45 d from radicle emergence, respectively. Thus, it can be concluded that the seeds of all three species have epicotyl morphophysiological dormancy. Hundred seed tests revealed that S. nux-vomica and S. potatorum seeds were desiccation-tolerant, while those of S. benthamii were desiccation-sensitive. Our study showed that species from seasonal habitats (S. nux-vomica and S. potatorum) have desiccation-tolerant morphophysiologically dormant seeds, while those from an aseasonal habitat (S. benthamii) have desiccation-sensitive morphophysiologically dormant seeds, revealing that their dormancy and desiccation tolerance behaviour are adaptations to their environment.

Seed desiccation-tolerance is a common feature of threatened taxa in metalliferous tropical grasslands from southeastern DR Congo

In Katanga (southeastern Democratic Republic of Congo), the flora of copper and cobalt deposits is highly threatened by mining. Until mining activity ceases and restoration can take place, seed banking is one of the strategies to be considered for the conservation of these metallophytes of which 32 are strict endemics. In the tropics, however, many species have recalcitrant (desiccation-sensitive) seeds, making them unsuitable for long-term conservation. This study aimed at characterising the seed storage behaviour of 14 taxa of concern from metalliferous tropical grasslands in order to determine their storability in ex situ seed banks. Germination tests of 38 populations from 9 different sites were undertaken on fresh seeds and after 6, 12, 24 and 96 months in dry-cold conditions. The vast majority (93 %) of the sampled species exhibited high seed viability (>75 %). For each taxon studied, there was no significant decline in seed viability during storage. In general, seeds germinated faster after 8 years of storage. This study provides evidence that seed desiccation-tolerance is common among the metallicolous species of Katanga. This highlights their ability to be stored under dry-cold conditions, which opens the way for ex situ conservation programs in seed banks.

Short Communication: Seed germination, seedling survival and storage behavior of Koompassia excelsa (Leguminosae)

Abstract. Latifah D, Wardani FF, Zulkarnaen RN. 2020. Seed germination, seedling survival and storage behavior of Koompassia excelsa (Leguminosae). Nusantara Bioscience 12: 46-49. Koompassia excelsa (Becc.) Taub. (Leguminosae) is an important component of many tropical rainforests as an emergent canopy tree. Knowledge and application of germination strategies and increasing seedling survival of this species in many conservation efforts are essential as it is endemic to several areas in Southeast Asia. This research investigated the effects of the different moisture levels of the sowing media on the germination and seedling survival percentage of K. excelsa. The seeds exhibited faster germination percentage and higher seedling survival when sown in media with 33.2%-moisture. The seeds appeared to have intermediate storage behavior. Thus, sowing seeds in 33.2%-moisture media may promote seedling survival, which is an important part of regeneration as well as conservation of K. excelsa.

Influence of artificial ageing test on seed quality changes in Cassia angustifolia Vahl

Deterioration of seed is a complex physiological and biochemical process leading to failure of germination capacity. An experiment was conducted to determine the effects of seed ageing on senna and analyzed the physiological causes for deterioration in artificially aged seeds. The senna seeds were artificially aged for 2,4 and 6 days at 40 ± 10C and 98 ± 2% RH and the non-aged seeds were considered as control. From the results, it is concluded that physiological parameters like germination percentage, hard seed %, root length, shoot length, dry matter production, vigour index gradually decreased and abnormal seedling % and electrical conductivity was increased with increase in period of artificial ageing (two days of ageing to six days of ageing) in senna. The accelerated ageing technique was adopted to precisely predict the storage behaviour of seeds and also artificial ageing conditions (2 days) revealed the beneficial effects to increase the germination percentage (80%) and vigour index (8.8) of seeds. It might be due to breaking the hard seed coat dormancy in the freshly harvested senna seeds.

Conservation seed physiology of the ciénega endemic, Eryngium sparganophyllum (Apiaceae).

Knowledge of seed dormancy and optimal propagation techniques is crucial for successful ex situ restoration and reintroduction projects, and determining the seed storage behaviour of a species is critical for the long-term conservation of seeds, further supporting future ex situ efforts. Eryngium sparganophyllum (Apiaceae) is a globally critically endangered plant species endemic to ciénega wetlands of southwest North America. To support in situ and ex situ conservation efforts of E. sparganophyllum, we asked (i) how does the embryo: seed (E:S) ratio change over time once imbibed, (ii) how does germination respond with varying periods of exposure to cold (5°C) and warm (25°C) stratification, and concentrations of gibberellic acid (GA3). By answering these questions, (iii) can dormancy class be inferred, and (iv) what storage behaviour category is exhibited? To answer these questions, we collected seeds in Southern Arizona from one of the few remaining wild populations. We measured embryo growth and tested the effects of cold (0–18 weeks) and warm (0 and 4 weeks) stratification, and 0–1000 ppm gibberellic acid on germination. We also tested the effects of cold (−80°C) dry (~20% equilibrium relative humidity) storage on germination. We found that (i) embryos grow inside seeds prior to germination; (ii) compared to control, cold stratification for at least 6 weeks increased germination and warm stratification had no effect; (iii) 1000-ppm GA3 had the highest germination success; (iv) therefore this species exhibits morphophysiological dormancy; and (v) seeds are orthodox and can therefore be conserved using conventional storage methods. This information will aid managers in the propagation of E. sparganophyllum that is crucial for in situ reintroduction and restoration projects, and seed banking represents a critical ex situ conservation strategy for the preservation of this species.

Seed germination and storage studies in seed-fertile Musa indandamanensis and its conservation

The quest for prospecting crop wild relatives in search of traits of economic importance has been gaining importance worldwide. Endemic species of such significance need to be given urgent attention for conservation, not only for their future potential uses in modern day agriculture but also due to the roles they play in the ecosystem of their areas of origin and rather narrow distribution. In this research, various aspects of assisted regeneration viz. pretreatment, substrate, storage life, stage for transplanting and post-transplanting survival were studied in an endemic, threatened wild banana species (Musa indandamanensis). Based on germination percentage, growth parameters, seedling vigour index and seedling survival, treatment of freshly extracted seeds with 0.1% KNO3 for 24 h prior to sowing in vermicompost as substrate was recommended for mass multiplication of the species. Seed storage behavior was studied in the species, which suggested that the species exhibits intermediate seed storage behavior. Seed viability was reduced over time especially after three months of storage and corresponding reduction in seedling vigour index was also recorded. Based on photosynthetic pigments analysis, eight leaf stage was found to be the best for transplanting the seedlings in the field with 100% survival. The species was conserved in field gene bank and Biological Park for facilitating its characterization and subsequent utilization.

Seed freeze sensitivity and ex situ longevity of 295 species in the native Hawaiian flora.

PremiseEx situ seed banking is critical for plant conservation globally, especially for threatened floras in tropical ecosystems like Hawai‘i. Seed bank managers must maximize longevity, and species managers must plan restoration before seeds lose viability. Previous observations suggested some native Hawaiian seeds lost viability in frozen storage (−18°C). We investigated seed storage behavior in the Hawaiian flora to optimize storage conditions and recommend re‐collection intervals (RCI) to maximize viability of stored seeds.MethodsUsing 20+ years of real‐time seed storage viability data, we tested freeze sensitivity for 197 species and calculated RCIs for 295 species. Using paired tests of accessions stored >2 yr at 5°C and −18°C, we developed an index of relative performance to determine freeze sensitivity. We calculated RCIs at 70% of highest germination (P70).ResultsWe identified four families (Campanulaceae, Cyperaceae, Rubiaceae, and Urticaceae) and four genera with seed freeze sensitivity and six additional genera with likely freeze sensitivity. Storage longevity was variable, but 195 species had viability >70% at the most recent tests (1 to 20+ yr), 123 species had RCIs >10 yr, and 45 species had RCIs <5 yr.ConclusionsFreeze sensitive storage behavior is more widely observed in Hawai‘i than any other regional flora, perhaps due to insufficient testing elsewhere. We present a new protocol to test seed freeze sensitivity, which is often not evident until 2–5 years of storage. Re‐collection intervals will guide restoration practices in Hawai‘i, and results inform seed conservation efforts globally, especially tropical and subtropical regions.

Seed storage behaviour of Buxus wallichiana Baillon: An important woodcraft species of Indian Himalayan region

Seeds of Buxus wallichiana Baillon are dormant and not much information is available on their shelf life under storage conditions. Therefore, this study was conducted to investigate the seed storage behaviour of B. wallichiana, an important woodcraft species of the Indian Himalayan Region. Healthy matured fruits of B. wallichiana were collected from Matkangra block, Chakrata Forest Division of Uttarakhand. The seeds were extracted, cleaned, processed manually and their initial viability was tested through germination test. After initial viability determination, seeds were processed and placed in air-tight plastic boxes for storage at four temperatures viz., ambient room temperature (Control), 5°C, 15°C and -20°C. Thereafter, at every two months interval, germination test was conducted to assess the viability of the stored seeds. The results revealed that the initial viability of freshly collected seeds was 26.66 per cent and it took 7.83 days to complete germination. After two months of storage the germination percentage increased in the seeds stored at all the temperatures going up to maximum (73.33%) in the ones stored at -20°C followed by 15°C (66.67%) as compared to 50% in the seeds stored at room temperature. Similarly, the mean germination time also increased proportionally, longest being 44 days for seeds stored at -20°C. Seeds stored at ambient room temperature lost viability completely at 6 months storage duration while almost half the viability was lost in seeds stored at 15°C (36.67%) and -20°C (26.67%). From present study, it can be concluded that the longevity of the B. wallichiana seeds is around 12 months when the seeds are stored at lower temperatures, maintaining the viability about 23% at 5°C and 15°C and 16.67 % at -20°C.

Intraspecific variation in seed germination and storage behaviour of Cordia tree species of subtropical montane forests of Argentina: Implications for ex situ conservation

Cordia americana, C. saccelia and C. trichotoma are native trees of the subtropical Andean forests of Argentina. Due to their high value as a wood source, these species are under threat from the over-exploitation of their populations and from changes in land use. Knowledge of seed biology may contribute to clarifying their regeneration ecology and establishing management policies and conservation programmes. We studied seed mass, seed germination, seed desiccation tolerance and seed storage behaviour in seeds from different populations of each species. Seed mass differed among the populations of each species. For C. americana and C. saccelia, germination percentages (GP) varied among populations and light and temperature conditions. For all species and populations, GP was not affected by seed population or desiccation treatments, but the time to germination (t50) increased after drying. GP decreased and t50 increased in seeds stored with 8–10% MC at 35 °C for three months for all species and populations. Seeds stored with 8–10% MC at 20 °C and with 3–5% MC at 35 °C also showed deterioration depending on the species. Differences in germination requirements, desiccation tolerance and storage behaviour were not related to seed mass. These results indicate that (1) all Cordia species seeds show orthodox storage behaviour, (2) both moisture content and temperature are key factors in Cordia seed storage and (3) some populations within a species are more sensitive to desiccation and storage conditions than others. Thus, these species and populations could be preserved in seed banks, but the germination, desiccation and storage behaviour variability among populations must be considered before germination and storage protocols are established. This information will be very useful for designing restoration, reforestation, plant propagation and in situ and ex situ conservation programmes for these Cordia species.

A combination of approaches evidenced seed storage behaviour in the miracle berry Synsepalum dulcificum (Schumach. et Thonn.) Daniell

BackgroundKnowledge on seed storage behaviour is crucial for planning conservation strategies of plant genetic resources particularly in economically promising but endangered species like Synsepalum dulcificum, viewed as recalcitrant-seeded species albeit sound evidence was lacking. In this study, we combined an experimental approach based on critical moisture content and storage environment analysis, and the seed-coat ratio–seed dry mass (SCR-SM) model to clarify the seed storage behaviour in the species. Seed moisture content at shedding was determined and effects of dehydration and cold storage on seed viability, germination and subsequent seedling vigour were analysed. The probability for dessication-senstivity [P(D-S)] was also determined.ResultsOur findings indicated that S. dulcificum seed moisture content at shedding was 36.60% with nearly 100% viability. Seed dehydration below 20% moisture content induced a total loss of viability whereas low temperature storage (at 10 °C or 4 °C reduced shelf life to a maximum of 7 days. More importantly, S. dulcificum seed storage at 0 °C was highly detrimental and resulted in a total loss of viability whatever the storage duration. Only a storage at 25 °C helped expand the shelf life to 28 days. However, at 28 days storage the viability was extremely low with almost no germination. The probability for dessication-senstivity P(D-S) in the species is largely greater than 0.5. Seed dehydration and storage environment highly affected subsequent germination rate and seedling vigour. While dehydration improved seedling performance storage at low temperature rather inhibited seedling growth.ConclusionTaken together, these findings are the first to set evidence of recalcitrance in S. dulcificum and serve hands-on information for practical handling of the seeds and designing sustainable conservation practices for adequate future breeding programme in the species.