Ultra-dry Seeds Research Articles

Biochemical and physiological studies in ultra-dried seeds of cotton, safflower and groundnut during various storage conditions

An experiment was conducted at National Bureau of Plant Genetic Resources, New Delhi to assess physiological and biochemical parameters to identify factors contributing to the loss of seed viability. Ultra-dried seeds of Cotton, Safflower and Groundnut stored at different MTS and ambient condition, viz. Cotton MTS 3.3%, Cotton Ambient 3.3%; Safflower MTS 6%, Safflower Ambient 3.8%; Girshell MTS, Gir Ambient 6.2% were used for present study. Result showed significant difference for all the physiological and biochemical traits as the seeds that were stored at MTS condition having high germination percentage, high vigour index, less moisture content, and lower Electrical conductivity (E.C.) and higher Dehydrogenase activity in comparison with seeds that were stored at Ambient condition. In SDS-PAGE profile of Cotton, Safflower and Groundnut some of the old bands were found to be missing at Ambient condition while some new bands were found to be appear in case of seeds that were stored at MTS condition. Deterioration was observed in seeds that were stored at Ambient condition. Whereas seeds that were stored at MTS condition were not deteriorated as much when compared to seeds that were stored at Ambient condition.

Effects of ultra-dry storage on seed germination and seedling growth of <i>Handeliondendron bodinieri</i>

(H. Lév.) Rehder is a rare, endangered, and therefore, protected tree species native to China. However, there are serious limitations to the effective protection of the species, including a low seed germination-rate and difficult storage due to a high seed oil-content. Here, we evaluated the feasibility of ultra-dry seed storage and its effects on seedling growth. We used the silica gel method to prepare ultra-dry seeds with different moisture contents to find an optimal moisture content range (2.54%–4.77%). Ultra-dry treatment improved storability of . Furthermore, seeds with a moisture content of 4.77% stored at room temperature, and seeds with a moisture content of 3.97% stored at 4 °C yielded the best results. Priming with an appropriate concentration of polyethylene glycol had a certain repairing effect on ultra-dry stored seeds and improved seed vigor, with a two-day priming treatment with 20% polyethylene glycol having the best effect. Finally, compared with sand storage at 4 °C, ultra-dry storage promoted seedling growth and root development; furthermore, it alleviated storage damage to seeds, promoted soluble sugar and soluble protein accumulation, and increased seedling nitrogen, phosphorus, and potassium uptake. Therefore, ultra-dry storage can be effectively used to preserve seeds. Specifically, low-temperature storage of ultra-dry seeds with a moisture content of 3.97% enhanced seed vigor, and seedling growth and development.Handeliodendron bodinieriH. bodinieri seedsH. bodinieriH. bodinieriH. bodinieri

Effect of ultra-drying on storability and vigour of onion seeds

Onion seeds are poor storers they have one of the loweststorability among cultivated crops. Seed moisture is one ofthe critical factors which determines the seed storability.The effect of ultra-drying of onion seeds on seed storabilityand seed vigour was studied. Seeds of three onion varietiesBhima Dark Red, Bhima Shakti and Bhima Safed were driedin 2:1 beads to seed ratio (w/w) for 96 hours and packed andstored in moisture impervious pack for 12 months underambient conditions. The initial moisture of seeds was 8.46%- 5.25%, which reduced to 3.48 - 2.91% at after 96 hours. Theultra-dried seeds had higher seed viability and vigour incomparison to control (undried seeds). At the end of 12months of storage, the average seed germination in ultradriedseeds was 81% whereas in control it was 52%. Incomparison to control at the end of 12 months, the ultradriedseeds had 23.82%, 33.80%, 83.12% and 98.60% higherseedling length, seedling dry weight, vigour index-I andvigour index-II. The ultra-dried seeds also recorded lowerelectrical conductivity indicating lower membranedegradation during storage. Thus, drying of onion seed in2:1 beads to seed ratio for 96 hours is beneficial in enhancingthe storability of onion seeds.

Standardization of ultra- seed drying of okra cv. Kashi Kranti with Zeolite beads and silica gel

Ultra-dry storage, also called low moisture content storage, is a technique for decreasing seed moisture content to below 5-6 per cent using different methods and then stored hermetically at ambient temperatures. Though sun drying is common practice to dry the seeds, it is difficult to bring down seed moisture where high humidity and high temperature is frequently fluctuating. Use of seed dryer also a best alternative to reduce the seed moisture. But it may affect the viability due to temperature fluctuation at the time of seed drying. Zeolite beads (aluminum silicate) and silica gel are desiccants, which can be utilized to Ultra- dry the seeds even in fluctuated temperature and RH without affecting quality of seeds. In this study, standardization of the drying method performed by mixing okra cv. Kashi Kranti seeds with zeolite beads and silica gel, separately, in the ratio of 1:0.5, 1:1, 1:2 and 1:3 (seed: desiccant, by weight) in an air tight container and kept at room temperature. Initial moisture content of seeds (10.5%) was estimated by hot air oven method. Seeds were separated from desiccant and estimated for moisture content after 24h, 48h, 72h, 96h and 120h of drying. Moisture content of the seeds was noted down at every 24h interval. At the end of the experiment, final moisture content of dried seeds was estimated. It was observed that seed drying with zeolite beads was faster than silica gel. Significantly higher moisture content was removed from seeds by zeolite beads, and final moisture content of seeds dried with zeolite beads reached 4.59% in 1:3 ratio, which was higher moisture elimination than seeds dried with silica gel in the same ratio 6.21%. Since, hard seed formation is a problem in over dried okra seeds, germination test were conducted to know the germination (%) and vigour of dried seeds. Germination test reveals no reduction in germination (%) and no hard seed formation even in 1:3 ratio of seeds with zeolite beads. More than 80% germination was observed in all drying conditions and non-dried control which was on par with each other’s. Further work is necessary to know the storability of ultra-dried seeds under air tight condition.

Ultra dry seed storage-a cost effective method for conservation of germplasm and commercial seeds of papaya

Studies on ultra dry seed storage were undertaken in papaya to find out its effect on seed longevity under ambient and controlled temperatures. Fresh seeds of cvs. Arka Prabhath and Arka Surya dried to 4.1% and 4.2% moisture content, respectively could maintain initial viability and vigour up to 42 months and 36 months in cv. Arka Prabhath and cv. Arka Surya respectively, under ambient temperature. However, ultra dry seeds of Sunrise Solo with 3.6% m.c. showed reduced germination immediately after drying than seeds with 8% m.c. indicating reduction in m.c. below 4% may be harmful. Whereas seeds with moisture content of 7.5–8.1% showed decline in seed viability and vigour after 18 months of storage under ambient temperature and rapid decline was noticed after 30 months of storage, reaching 50% viability in cv. Arka Prabhath, 17% in cv. Arka Surya and 0% in Sunrise Solo at 42 months. At 15°C seeds with 7–8% moisture content showed no decline in viability and vigour after 42 months of storage in Arka Prabhath and Arka Surya and upto 66 months in Sunrise Solo. Whereas, ultra dry seeds of Arka Prabhath and Arka Surya could maintain more than 85% germination up to 72 months. Similarly, ultra dry seeds of Sunrise Solo maintained its germination and vigour up to 72 months. Similar trend was observed for field emergence.

Deterioration of quality soybean seeds (Glycine Max (L.) Merr. AGS 190) at harvest stages, seed moisture content and storage temperature in Malaysia

Soybean [Glycine max (L.) Merill AGS 190) is an important vegetables and oil in the Asian communities like Malaysia. Seed deterioration is a harmful feature of agriculture crops which hindered quality seed of Soybean. Thus, the purpose of the study is to determine the effect of non-ultra-dry and ultra-dry seed moisture content stored in room temperature and cold room conditions for seed harvested stages on the quality or seed deterioration of soybean seeds (AGS 190) which grown under the humid tropical region. This study was conducted at Faculty of Agriculture, University Putra Malaysia in three harvested stages such as R6 (Full seed stage), R7 (Commencement of maturity period), and R8 (Fully maturity stage), moisture content (12% non-ultra-dry and ≤5% ultra-dry) and storage temperature (room storage at 25 to 30oC and cold room storage at 10oC). The result of this study showed that the seed deterioration rate was less in harvest stage R7 compared to R6 and R8 especially for ultra-dry seeds. In addition, seed deterioration can decrease at room temperature by the ultra-dry treatment compared non-ultra-dry but deterioration was higher for non-ultra-dry seed during storage at room temperature than cold room.

Effect of ultra dry seed storage on longevity of onion (Allium cepa) and china aster (Callistephus chinensis) under ambient and controlled temperatures

Ultra dry seed storage was studied in onion (Allium cepa L.) and china aster [Callistephus chinensis (L.) Nees] to find out its effect on seed longevity under ambient and controlled low temperatures. Seeds of onion cultivars Arka Kalyan and Arka Niketan ultra dried to 2.8 and 2.6 %, respectively, and seeds of china aster cultivar Arka Kamini ultra dried to 3.0% were compared with seeds of respective cultivars having moisture content close to recommended levels for packing in moisture proof containers. These seeds were hermetically sealed in aluminium pouches and stored at ambient and controlled (constant 15°C) temperatures. The initial germination in onion was 90.0 and 88 % in Arka Niketan and Arka Kalyan, respectively, and it remained unaffected after ultra drying. During storage, ultra dry seeds and seeds with ~5% moisture content of both varieties showed no significant reduction in seed germination, first count, seedling vigour and field emergence even after 54 months of storage both under ambient and controlled temperatures. In china aster, seeds with 5.9% moisture showed decline in seed viability and vigour under ambient temperature after 18 months of storage and rapid decline was noticed after 24 months of storage, reaching zero at 36 months but at 15°C showed no decline in viability up to 48 months of storage. Ultra dry seeds maintained higher viability and vigour at both ambient and at 15°C even after 48 months of storage. Genetic fidelity tests on onion seed clearly demonstrated that neither the profiles of soluble proteins and enzymes nor the DNA were affected by ultra drying.

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Effects of Ultradry Storage on Fluidity of Plasma Membrane of <em>Haloxylon persicum</em> Seeds

The DPH fluorescent probe (1, 6-diphenyi-1, 3, 5,-hexatriene) was used to study the effects of ultradry seed storage on the fluidity of plasma membrane. Results indicated that the micro-viscosity of plasma membrane of ultradried seeds had no significant changes compared with the Haloxylon persicum seeds which were stored under 4°C condition. However, there was a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seeds.

Effect of Moisture Content on Melilotus suaveolens Seed Quality During Ultra-drying Storage

In order to enhance the seed storability and supply high-quality seeds for vegetation restoration in the arid and semiarid regions in Northwest China, the effects of ultra-drying and accelerated aging on the physiological characterstics of Melilotus suaveolens seeds were studied. Melilotus suaveolens seeds were dried in a desiccator containing silica gel to 80, 53, 42, 33, 23 and 16 g • kg−1 of moisture contents (MC), respectively. The parameters of the seed quality including germination energy (GE), germination percentage (GP), relative conductivity (RC), dehydrogenase activity (DA) and α-amylase activity (AA) were determined after ultra-drying and accelerated aging. The results showed that ultra-dried seeds with 42 g · kg−1 of MC showed the minimum changes of GE and GP before and after seed aging. Moreover, ultra-dry seeds with 42 g · kg−1 of MC showed higher DA and AA, and lower RC than non-ultra-drying seeds. Therefore, ultra-drying to 42 g · kg−1 of MC was helpful for M. suaveolens seed storage.

Effect of ultradrying on germination and physiological and biochemical characteristics of Haloxylon persicum

This study was to determine whether the vigor of the Haloxylon persicum seeds can be maintained at a higher level and their storage characteristics can be improved by ultra-dry storage. Moisture content of H. persicum seeds was dried to 7.62, 6.73, 5.23, 4.24, 3.24 and 1.02% in a desiccating container with silica gel, and stored at 25, 4 and -20°C for 12 months. The results showed that the H. persicum seeds became more tolerant to aging condition if they could be dried to below 3.24% of moisture content. Under the same aging condition, the germination of seeds with 3.24% of moisture content decreased greatly, while that of ultra-dry seeds still kept a high level. The dehydrogenase activity of ultra-dry seeds was higher than that of the control (moisture content 3.24%, aging treatment). The results indicated that dehydrogenase, guaiacol peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) activities of the ultra-dry seeds were higher than those of the control seeds. The results demonstrated that an appropriate ultradried H. persicum seeds could persist and ultradrying treatment was an ideal method of seed storage.

High viability recorded in ultra-dry seeds of 37 species of Brassicaceae after almost 40 years of storage

Final germination percentages of 25 accessions of Brassicaceae from the UPM (Universidad Politecnica de Madrid) seed bank were evaluated after 38-40 years of storage. The seeds were preserved at temperatures between −5°C and −10°C in flame sealed vials containing dehydrated (blue) silica gel. Seed moisture content ranged between 0.3 and 3% (f.w.b) after storage. Most accessions (ten out of twelve) with high initial (before storage) germination rate (low initial dormancy) maintained these high values almost intact after storage (91-100% germination). In two accessions, seeds had developed a secondary dormancy, which was successfully overcome by scarification. A second set of 13 accessions had low initial germination rates (0-20%, i.e. high initial dormancy). In one accession, dormancy had been broken during storage (92% germination) and in nine accessions germination was significantly enhanced by GA3 and or scarification. Seed dormancy most often decreases during storage but it may also increase or remain unchanged. The consideration of these dormancy variations is very important when evaluating seed longevity in wild species. The preservation method based on silica gel and low temperature (−5°C and −10°C) has proved highly efficient at least for Brassicaceae. Vials with seeds of 12 additional accesssions had remained at room temperature during 34-39 years and those seeds showed germination percentages that were similar to those preserved in the cold room. This result suggests that temperature might not be as important as expected - at least for medium-term preservation - and supports the possibility of using ultra-dry methods.

Survival and vigour of ultra-dry seeds after ten years of hermetic storage

Seeds of carrot, groundnut, lettuce, oilseed rape and onion were stored hermetically in laminated aluminium foil packets in four environments (dry or ultra-dry moisture contents combined factorially with temperatures of 20 degrees C or -20 degrees C), replicated at several sites. After ten years' hermetic storage, seed moisture content, equilibrium relative humidity, viability (assessed by ability to germinate normally in standard germination tests) and vigour were determined. After a decade, the change in seed moisture content of samples stored at -20 degrees C was small or nil. Except for groundnut and lettuce (where loss in viability was about 8 and 3%, respectively), no loss in viability was detected after 10 years' hermetic storage at -20 degrees C. In all cases, there was no difference in seed survival between moisture contents at this temperature (P > 0.25). Comparison of seed vigour (root length and rate of germination) also confirmed that drying to moisture contents in equilibrium with 10-12% r.h. had no detrimental effect to longevity when stored at -20 degrees C: the only significant (P < 0.05) differences detected were slightly greater root lengths for ultra-dry storage of four of the six seed lots. Seed moisture content had increased after a decade at 20 degrees C (generally to the level in equilibrium with ambient relative humidity). Hence, sub-zero temperature storage helped maintain the long-term integrity of the laminated aluminium foil packets, as well as that of the seeds within.

Starch Mobilization in Ultradried Seed of Maize (Zea mays L.) During Germination

Abstract: The effects of ultradry storage on the starch mobilization in maize (Zea mays L.) seed after aging were investigated. The results indicated that there were no significant differences in the content of ATP, starch, and soluble sugar, as well as the activity of amylase, between ultradried seeds and seeds stored at −20 °C during germination. These results were consistent with the higher level of vigor of the ultradried seed. Sieve tube introduction of a fluorescence dye (carboxyl fluoresceindiacetate) and laser confocal microscopy were used to study the development of plasmodesmata in the ultradried seeds. The results indicated that plasmodesmata developed well in ultradried seeds. Fluorescence analysis also showed that the fluorescence intensity in the radicle of ultradried seeds was stronger than that in seeds with a higher moisture content. This suggests that ultradry treatment has no adverse effects on the seeds. After seed imbibition, cell orgaelles could be resumed. It is concluded that ultradry seed storage is beneficial for maintaining seed vigor and that starchy mobilization proceeds regularly during germination.(Managing editor: Ping HE)

Effects of ultradry storage on fluidity of plasma membrane of seed

The effects of ultradry seed storage on the fluidity of plasma membrane have been investigated using the DPH fluorescent probe (1, 6-diphenyi-l, 3, 5,-hexatriene). The results demonstrated that the micro-viscosity of plasma membrane of ultradried seeds has no significant changes compared with the seeds which were stored under -20°C condition. However, there is a little adverse effect on the seeds with extreme dehydration. The results were consistent with higher vigor level of ultradried seed. It indicated that ultradry seed storage could maintain the physiological function of seed, protect the integrity of the membrane and improve the storability of seed. Furthermore, the results also revealed that sugar has the effect on protecting membrane structure and preserving the fluidrty of the plasma membrane under seed dehydration. In the meantime, some mechanism about ultradry seed storage and the tolerance of dehydration of seed have been discussed.

How to store seeds to conserve biodiversity

Zheng et al.1 pointed out the potential advantages of ‘ultra-dry’ (less than 5% moisture content) seed storage for the long-term genetic conservation of plants, based largely on their studies of seed vigour. Here we support their suggestion, using our data from several years ago which showed that ultra-dried seeds have increased survival periods2.

Ultradry Seed Storage: Improved Strategy and Technology for Germplasm Conservation

A research program on ultradry seed storage (supported by IBPGR)was carried OUt at the Beijing Botanical Garden from 1 989~ 1 993.Various kinds of seeds of more than 20 speices were used.Many significant rsults and findings were obtained ,and some new concepts were derived from them.Based on a series of experiments,it was concluded that ukradry storage has the potential to be an alternative technique for germplasm conservation in gene banks.Advances of researches in detail were repo rted in