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1.
Veselova TV Veselovskiĭ VA 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2012,52(1):50-57
The aim of this work was to determine which processes in air-dry seeds result in bimodal changes of the pea seed quality under the influence of low doses of gamma-radiation. Pea seeds (cv. "Nemchinovsky-85", harvest 2006, 82% germination persentage) were exposed to gamma-radiation at doses of 3, 10 and 100 Gy The germination percentage decreased to 45% four days after irradiation at the dose of 3 Gy, rised up to 87% at doses of 10 Gy, while the dose of 100 Gy killed the most part of seeds. Seed fractions differing in quality were selected using the metod of Room temperature phosphorecsence (RTP): strong seed frasction I from non-irradiated seeds; weak seed fraction II from the seeds irradiated at a dose of 3 Gy; dead seeds from the seeds irradiated at a dose of 100 Gy. ThermoChemiLuminecnsece (TCL) of seed powders and cotyledons was used. It was shown that the increase of the TCL level in the temperature range from 50 to 110 degreesC was associated with the lipid peroxidation products. The TCL level of seeds subjected to gamma-irradiation at a dose of 3 Gy was similar to that of non-irradiated seeds in the temperature range 50 to 100 degreesC. Therefore, lipid peroxidation was not the cause of the abnormal seedling appearance. The TCL level within this temperature range was increased only in seeds subjected to y-irradiation at a dose of 100 Gy. The TCL level at 150 degreesC was in proportion with the exogenous glucose amount. The increased TCL level of seeds subjected to y-irradiation at a dose of 3 Gy at 150 degreesC resulted from the increase of the glucose content. This means that the transition from the fraction of strong seeds into the fraction of weak ones was the result of the activation of hydrolysis processes. Decrease in the water content of seeds testified to utilization of bound water in this process. The decrease of the glucose content in the "improved" seeds subjected to gamma-irradiation at a dose of 10 Gy most probably indicates the participation of glucose in the amino carbonyl reaction. The latter could be the reason for the increased water content in the "improved" seeds and a decreased water permeability of cell membranes. 相似文献
2.
Using the method of room temperature phosphorescence (RTP), we divided air-dry pea (Pisum sativum L.) seeds subjected to accelerated ageing (40°C, 85% relative humidity) into three fractions: (I) high-quality seeds, (II) weakened seeds, and (III) dead seeds. In the process of ageing, seed germinability firstly decreased and then increased due to so-called “improved” seeds of fraction II, which returned to fraction I as judged from the RTP level; the germinability of these seeds became equal to that of fraction I seeds. Seeds capable of germination (fractions I and II) differed in the rates of imbibition, which depended on plasma membrane permeability (opened or closed water channels) but not on the presence of the seed coat. A low activation energy of seed imbibition in fraction II (less than 5 kcal/mol) indicates that water channels are open. A mercury-containing compound (5 μM p-chloromercuribenzoate (PCMB) reduced the rate of water uptake by these seeds, and dithiothreitol restored it. A high activation energy of fraction I seed imbibition (more than 12 kcal/mol) corresponded to the water uptake mainly across the lipid bilayer when water channels are closed. PCMB did not affect the rate of fraction I seed imbibition. We supposed that mature air-dry pea seeds had open water channels. During the first stages of fraction I seed imbibition, these channels were closed, limiting water uptake. NaF (100 μM), an inhibitor of phosphatase, prevented channel closing and accelerated the imbibition of fraction I seeds. It did not affect the imbibition rate of fraction II seeds, indicating their water channels to be opened. However, NaF did not affect the water uptake of “improved” fraction II seeds as well. It seems likely that their channels were closed during accelerated ageing but otherwise than via dephosphorylation. The results obtained indicate the possibility of water inflow regulation in the weakened seeds via the state of aquaporins, which form water channels in the membranes. 相似文献
3.
Hypoxia and Imbibition Injuries to Aging Seeds 总被引:2,自引:1,他引:1
Veselova T. V. Veselovskii V. A. Usmanov P. D. Usmanova O. V. Kozar' V. I. 《Russian Journal of Plant Physiology》2003,50(6):835-842
The development of hypoxia and primary injuries were examined during the imbibition of aging pea seeds (Pisum sativum L., cv. Nemchinovskii). The distribution of air-dry pea seeds by their room-temperature phosphorescence revealed the presence of two fractions (I and II) in a seed lot with 72% germinability and three fractions (I, II, and III) in a seed lot with 50% germinability. The water uptake during imbibition was slower in the fraction I seeds than in the fraction-II seeds. The fraction-I seeds produced normal seedlings, whereas the fraction-II seeds either produced seedlings with morphological defects (abnormal) or did not germinate at all. The fraction-III seeds were all dead. The phosphorescence of endogenous porphyrins, emitted only at low O2 content, was measured after 20-h seed imbibition. The fraction-I seeds emitted no discernible phosphorescence. The fraction-II comprised highly phosphorescent seeds incapable of radicle protrusion and moderately phosphorescent seeds producing abnormal seedlings. The fraction-II seeds experienced hypoxia during the imbibition because of rapid oxygen consumption by the embryo and restrictions to O2 diffusion imposed by the seed coat. In the fraction-I seeds, the rate of oxygen consumption by the embryo was slower and the seed coat resistance to oxygen diffusion was lower than in the fraction-II seeds. Therefore, hypoxia did not arise in the fraction-I seeds. The submergence of seeds in water caused lethal injuries. The imbibition of seeds without any contact with water caused no lethal damages but did not reduce the percentage of seeds dying of hypoxia. A slow imbibition of seeds in the media containing either an osmoticum (PEG) or an inhibitor of aquaporin channels (p-chloromercuribenzoate) prevented the lethal injuries at early stages of seed hydration and retarded the appearance of oxygen deficiency in fraction-II seeds. Different rates of water uptake by fraction-I and fraction-II seeds were controlled by permeability of cell membranes rather than by permeability of seed coat. It is proposed that low permeability of plasma membranes to water in fraction-I seeds results from the predominantly closed aquaporin channels, whereas a higher permeability of weak seeds (fraction II) is due to open channels. 相似文献
4.
Veselovskiĭ VA Veselova TV 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2007,47(1):28-33
Pea seeds (Pisum sativum L.) from the seed lot with 80% germinability were separated in fractions according to room temperature phosphorescence: strong seeds were assigned to fraction I, and weak seeds formed to fraction II. During imbibition, the seeds of fraction II exhibited twofold higher rates of water uptake and experienced hypoxia. Some of these seeds suffocated from hypoxia, and other seeds produced seedlings with morphological defects (such seeds were considered incapable of germination). One week after irradiation with the dose of 3 Gy, germination percentage decreased to 45%, which was caused by the increase of number of weak seeds. The germinability of seeds subjected to gamma-irradiation at doses of 7 and 10 Gy was similar to that of control seeds. In these sub-lots, there appeared so-called "improved" seeds, which were similar to non-irradiated seeds in terms of phosphorescence level, the rate of water uptake and germination percentage. It was shown with the use of PCMB that the difference in the rates of water uptake by seeds of fraction I and II depended on the permeability of cell membranes. The permeability was determined by the state of aquaporins ("open"-"closed"). The experiments with phosphatase inhibitor (NaF) shown that in seeds irradiated with dose of 3 Gy (fraction II), the mechanism of aquaporins closing was broken (phosphatase was inactivated). In "improved" seeds (after irradiation with dose of 10 Gy), aquaporins were closed irreversibly in air-dry state, when aquaporin dephosphorylation was unlikely. It was concluded that the abnormal increase (following the initially decrease) in germination of pea seeds after irradiation can be explained without invoking the hypothesis on hyper function of reparatory mechanism of at low doses of irradiation. 相似文献
5.
Veselovskiĭ VA Veselova TV Korogodina VL Florko BV Mokrov IuV 《Radiatsionnaia biologiia, radioecologiia / Rossi?skaia akademiia nauk》2006,46(6):691-696
Pea seeds (cv. 'Nemchinovskii-85', harvest of 2002, 80%-germination percentage) were exposed to gamma-radiation with doses ranging from 19 cGy to 100 Gy. One week after the irradiation with doses of 19 cGy and 3 Gy. the germination percentage decreased to 58 and 45%, respectively; at doses of 7 and 10 Gy it was 73 and 70% respectively. At greater doses (25, 50, and 100 Gy), germination percentage decreased in proportion. Anomalous changes in seed germination percentage (as a function of irradiation dose) were caused by the redistribution of irradiated seeds between fractions I and II. The measurements of room temperature phosphorescence in air-dry seeds and the phosphorescence of endogenous porphyrines of imbibing seeds showen that the germination decrease after the irradiation with low doses (19 cGy and 3 Gy) was caused by the increase in the number of weak seeds of fraction II, which had high rates of water uptake and suffered from hypoxia under seed coat. Some of these seeds suffocated from hypoxia, and other seeds produced seedlings with morphological defects (such seeds were considered incapable of germination). During storage of seeds irradiated at doses 19 cGy-10 Gy, the recovery of germination percentage (after its initial decrease) was caused by the decrease in seed number in fraction II. The subsequent germination decrease was caused by seed death. The higher was the irradiation dose, the faster were changes in germination percentage during storage of irradiated seeds. Bimodal changes in pea seed germination with the increase of y-irradiation dose has apparently the same origin as the changes in seed germination during accelerated ageing. 相似文献
6.
Lorenza M. Bellani Laura Salvini Antonio Dell’Aquila Anna Scialabba 《Acta Physiologiae Plantarum》2012,34(5):1789-1799
Seeds of Raphanus sativus L. subjected to accelerated ageing were investigated for reactive oxygen species (ROS) release and for content of vitamin E (tocopherol, TOC, and tocotrienol, TOC-3), fatty acids and phytosterols in seed coats, cotyledons and embryonic axes during germination. In unaged seeds, ROS release occurred mainly in seed coats of non-imbibed seeds and in seedlings (48?h of imbibition). TOC and TOC-3 were mainly represented by the ??-isoform, abundant in embryonic axes. Fatty acids were mainly found in cotyledons. In seed coat and embryonic axis, phytosterols consisted mainly of sitosterols. The effects of ageing were mainly visible in embryonic axes at 48?h of imbibition. Deterioration was associated with a decrease in fresh weight increase percentage, germination percentage, ??-TOC and total fatty acid content. An increase in ROS release from seed coats and in ??-TOC, ??-TOC, ??-TOC-3 content in embryonic axis was also observed. The use of ??-TOC and total fatty acids in embryonic axis as parameters of seed quality evaluation during storage was suggested. 相似文献
7.
Bovine brain hexokinase enhances the effect of Mn(II) on the longitudinal relaxation rate of water protons. Direct interaction of Mn(II) with the enzyme has been studied using electron spin resonance and proton relaxation rate enhancement methods. The results indicate that brain hexokinase has 1.05 ± 0.13 tight binding sites and 7 ± 2 weak binding sites with a dissociation constant, KD = 25 ± 4 μM and K′D = 1050 ± 290 μM, respectively, at pH 8.0, 23 °C. The characteristic enhancement ?b) for hexokinase-Mn(II) complex evaluated from proton relaxation rate enhancement studies, gave ?b = 3.5 ± 0.4 for tight binding sites and an average ?b = 2.3 ± 0.5 per site for weak binding sites at 9 MHZ. The dissociation constant of Mn(II) for tight binding sites on the enzyme exhibits strong temperature dependence. In the low-temperature region (5–12 °C) brain hexokinase probably undergoes a conformational change. Frequency dependence of the normalized relaxation rate for bound water at various temperatures has shown that the number of exchangeable water molecules left in the first coordination sphere of bound Mn(II) is about one at 30 °C and about two at 18 °C. Binding of glucose 6-phosphate to hexokinase results in large-line broadening of the resonances of anomeric protons of the sugar. However, no such effect was observed in the case of glucose binding. These results suggest different modes of interaction of these two sugars to hexokinase. Line broadening of the C-(1) hydrogen resonances of glucose caused by Mn(II) in the presence of hexokinase suggests the proximity of the Mn(II) binding site to that of glucose. A lower limit of 1330 ± 170 s?1 for the rate of dissociation of glucose from enzyme-Mn(II)-glucose complex has been obtained from these studies. 相似文献
8.
Claudia Hernandez-Aguilar Alfredo Cruz-Orea Rumen Ivanov Arturo Dominguez Aquiles Carballo Ivan Moreno Ricardo Rico 《Food biophysics》2011,6(4):481-486
The knowledge about a seed??s optical parameters is of great relevance in the seed technology practice. Such parameters provide information about its absorption and reflectance, which in turn is related to its color, quality, and health condition. The objective of the present study was to determine the optical absorption coefficient ?? for maize seeds (Zea mays L.) by means of the photoacoustic spectroscopy (PAS). Untreated seeds (I) and seeds dyed with methyl red (II) were used in this investigation. In addition, conventional reflectance measurements (obtained with the integrating sphere) were performed to validate PAS absorption measurements. The results show that the absorption spectra and reflection data of the seed samples are complementary. When used with thermally thick and optically opaque seeds, PAS may be considered as a potential diagnostic tool for the characterization of the seeds. 相似文献
9.
T. V. Vesetova V. A. Veselovsky A. B. Rubin P. Z. Bochvarov 《Physiologia plantarum》1985,65(4):493-497
Delayed luminescence (DL) excited by visible light has been observed in air-dry seeds of various plants. Changes in seeds of soybeans ( Glycine max L. W.) which occur during natural and accelerated aging were reflected in subsequent loss of vigor and DL increase. The increase of the luminescence is caused by the changes in seed biopolymers, leading to a decrease in their ability to take up water. The method makes it possible to measure DL from a single seed. With aging, the DL was shifted toward higher intensities and there was greater variability. By monitoring the DL of seeds it may be possible to evaluate their quality and storage capability. 相似文献
10.
N. V. Obroucheva I. A. Sinkevich S. V. Lityagina G. V. Novikova 《Russian Journal of Plant Physiology》2017,64(4):625-633
Life strategy of plants depends on successful seed germination in the available environment, and sufficient soil water is the most important external factor. Taking into account a broad spectrum of roles played by water in seed viability and its maintenance during germination, the review embraces early germination events in seeds different in their water status. Two seed types are compared, namely orthodox and recalcitrant seeds, in terms of water content in the embryonic axes, vacuole biogenesis, and participation of water channels in membrane water transport. Mature orthodox seeds desiccate to low water content and remain viable during storage, whereas mature recalcitrant seeds are shed while well hydrated but die during desiccation and cannot be stored. In orthodox Vicia faba minor air-dry seeds remaining viable at 8–10% water content in embryonic axes, the vacuoles in hypocotyl are preserved as protein storage vacuoles, then restored to vacuoles in imbibing seeds in the course of protein mobilization. However, in newly produced meristematic root cells, the vacuoles are formed de novo from provacuoles. In recalcitrant Aesculus hippocastanum seeds, embryonic axes have a water content of 63–64% at shedding and they lack protein storage vacuoles but preserve vacuoles preformed in maturing seeds. Independent of the vacuolar biogenetic patterns, their further trend is similar; they expand and fuse, thus producing an osmotic compartment, which precedes and becomes an obligatory step for the initiation of cell elongation. Prior to this, water moves in imbibing seeds through the membranes by diffusion, although the aquaporins forming water channels are present. In both seed types, water channels are opened and actively participate in water transport only after growth initiation. Aquaporin gene expression and their composition change in broad bean embryonic axes after growth initiation. This is the way how a mass water flow into growing seedling cells is achieved, independent of differences in seed water content and vacuole biogenesis patterns. 相似文献
11.
The chemical reactions that may lead to the loss of seed viability were investigated both during the accelerated aging and natural aging of soybeans ( Glycine max Merrill cv. Chippewa 64). Under conditions of accelerated aging (36°C and 75% RH), fluorescence of soluble proteins accumulated, which was closely correlated with the loss of seed germinability and vigor. We were able to show this correlation by using partially purified proteins for the assay. Fluorescence also increased in seeds under good storage conditions (5°C for up to 21 years), although there was a less significant correlation between seed viability and the accumulation of fluorescent products during the time of natural aging. The rise in protein fluorescence is interpreted as an increase of Maillard products. The carbonyl content of soluble proteins (a measure of the oxidative damage) did not change significantly during either accelerated aging or natural aging: however the elimination of carbonyls during germination seemed to be hindered in seeds that had poor germination. The Maillard reaction may be a consequence of the formation of reducing sugars through a gradual hydrolysis of oligosaccharides during aging. Preliminary evidence from the natural aging study showed that, when seeds were in the glassy state, the sugar hydrolysis was inhibited. These results suggest that the Maillard reaction and oxidative reaction may play an important role in seed deterioration. 相似文献
12.
Metabolism As a Function of Water Potential in Air-Dry Seeds of Charlock (Sinapis arvensis L.)
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Edwards M 《Plant physiology》1976,58(2):237-239
A new method is described for studying the metabolism of air-dry seeds. An initial pulse of (14)CO(2) was supplied to seeds maintained in air at controlled low water potentials for 6 months. Seeds were also infiltrated with 2-(14)C-acetate and with (14)C-l-leucine at 0 C, redried rapidly at 0 C, and maintained at controlled low water potentials for 4 to 6 weeks. The metabolism of the air-dry seeds was a function of the water content of the tissues, which was in equilibrium with the water potential at the seed surface. The fixation of (14)CO(2) and the utilization of 2-(14)C-acetate increased exponentially with water content. The incorporation of (14)C-l-leucine into protein increased linearly with water content. Metabolism was not reduced to a low rate except in air-dry seeds at the lowest water potentials (-1716 to -762 bars) with 4 to 6% water. 相似文献
13.
14.
Christophe Bailly Abdelilah Benamar Françoise Corbineau Daniel Come 《Physiologia plantarum》1996,97(1):104-110
Sunflower ( Helianthus annuus L.) seeds progressively lost their ability to germinate at 25°C, the optimal temperature for germination, after accelerated aging was carried out at 45°C (a temperature too high to permit germination) in water or at 76 or 100% relative humidity (RH). The deleterious effects of the high-temperature treatment increased with increasing seed moisture content. Incubation of seeds at 45°C in water resulted in electrolyte leakage, which indicated a loss of membrane integrity. A relationship between leakage and loss of seed viability could not be assumed, since no increase in electrolyte efflux occurred after aging al 100% RH. Accelerated aging induced accumulation of malondialdehyde, suggesting that seed deterioration was associated with lipid peroxidation. However, there was no direct relationship between lipid peroxidation and deterioration in membrane integrity. Loss of seed viability was also associated with a decrease in superoxide dismutase, catalase and glutathione reductase activities. Finally, the results obtained suggest that sunflower seed deterioration during accelerated aging is closely related to a decrease in the activities of detoxifying enzymes and to lipid peroxidation. 相似文献
15.
Incubation of cotton seeds (Gossypium hirsutum, cv. Acala S.J.2) at 20 °C and 95% r.h. for up to 12 d results in an increasein seed water content and in a higher rate of seedling development.When seed vigour is measured by tolerance to high temperaturestorage (aging conditions) or tolerance to low temperature andsalinity during germination, seeds incubated for up to 4 d aremore vigorous than the control seeds. Hence, such a presowingtreatment of seed could be used for seed invigoration. As theincubation proceeds, although a higher growth rate of seedlingsis obtained at optimal conditions, the tolerance to stress conditionsdeclines proportional to the duration of incubation. Results of chemical and biochemical examinations of the incubatedseeds are compared with those of seeds during normal imbibitionfor germination. The early stage of germination (up to 4 h)is accompanied by a decrease in reducing sugars and amino acids.At the later stage, an increase of these components and a decreasein the lipid fraction occur. During the first 4 h, an increaseand decrease of phosphoenolpyruvate carboxylase and of malicdehydrogenase occur. According to the chemical and biochemicalmarkers, it is evident that seed treatment at 20 °C and95% r.h. results in pregermination biochemical activities. Thefirst 4 d seem to be equivalent to the first 3 h of germinationunder normal conditons. At this period of time, degradationprocesses are taking place. If incubation is continued the resynthesisstage appears to be retarded by the low moisture available andtherefore degradation processes continue, resulting in lossof seed vigour. The resynthesis ability may therefore be a prerequisitefor the following steps in seed germination. 相似文献
16.
Vegetation recovery on Mount Koma, Hokkaido, Japan, has been slow after the catastrophic eruption in 1929, due to undeveloped soil and limited plant colonization. Nowadays, the seedling establishment is supported mostly by a nurse plant, Salix reinii forming shrub patches, facilitates the plant colonization. Although the effects of shrub patches should differ with patch sizes, the size effects have not been examined well. To examine the size effects, seed-sowing experiments were conducted on two common pioneer herbaceous species, Miscanthus sinensis and Polygonum sachalinense, in the field. The seed germination and seedling survival were monitored by the seeds sown into S. reinii patches (0.97 m2–4.12 m2 in area) for 4 months during snow-free periods. Microenvironments altered by the patches were measured. Lab-experiments were performed to characterize the seed germination and seedling growth.Larger patches decreased light intensity and temperature more and increased litter and water content. The large patches promoted the seed germination of the two species. Interspecific interactions, examined by a seed mixture experiment, showed that the interaction increased the seed germination on M. sinensis and decreased that on P. sachalinense. On the lab-experiments at three temperatures (15, 20 and 25 °C), M. sinensis seeds germinated more at higher temperatures and obtained higher seedlings biomass. P. sachalinense germinated the seeds more at 20 °C and grew faster at lower temperatures. The total biomass of the two species was reduced by shade that intercepted 50% of light intensity. The seed germination and seedling growth of these two species became higher on litter with 2 cm in depth than on no litter. Soil water supported seed germination when the seeds of these two species were mixed while the water reduced the growth of P. sachalinense seedlings. Therefore, the dry soils were suitable for their growths. In all the treatments, P. sachalinense seedlings showed higher mortalities than M. sinensis.In conclusion, the large patches facilitated more to the colonization of pioneer plants via seed germination and growth. Large patches acted as a nursery supporting the natural regeneration in the disturbed area by improving litter accumulation, maintaining soil water, reducing strong light and/or protecting from heat. 相似文献
17.
Background and Aims
Using two parental clones of outcrossing Trifolium ambiguum as a potential model system, we examined how during seed development the maternal parent, number of seeds per pod, seed position within the pod, and pod position within the inflorescence influenced individual seed fresh weight, dry weight, water content, germinability, desiccation tolerance, hardseededness, and subsequent longevity of individual seeds.Methods
Near simultaneous, manual reciprocal crosses were carried out between clonal lines for two experiments. Infructescences were harvested at intervals during seed development. Each individual seed was weighed and then used to determine dry weight or one of the physiological behaviour traits.Key Results
Whilst population mass maturity was reached at 33–36 days after pollination (DAP), seed-to-seed variation in maximum seed dry weight, when it was achieved, and when maturation drying commenced, was considerable. Individual seeds acquired germinability between 14 and 44 DAP, desiccation tolerance between 30 and 40 DAP, and the capability to become hardseeded between 30 and 47 DAP. The time for viability to fall to 50 % (p50) at 60 % relative humidity and 45 °C increased between 36 and 56 DAP, when the seed coats of most individuals had become dark orange, but declined thereafter. Individual seed f. wt at harvest did not correlate with air-dry storage survival period. Analysing survival data for cohorts of seeds reduced the standard deviation of the normal distribution of seed deaths in time, but no sub-population showed complete uniformity of survival period.Conclusions
Variation in individual seed behaviours within a developing population is inherent and inevitable. In this outbreeder, there is significant variation in seed longevity which appears dependent on embryo genotype with little effect of maternal genotype or architectural factors. 相似文献18.
Freeze-fracture electron microscopy was used to study water content related freezing resistance in Grand Rapids lettuce seeds. Consistent and recognizable conformational changes occurred in lipid-water phases of lettuce seeds at different moisture contents. In air-dry lettuce seed cotyledons, the lipids lying in spherical lipid bodies near the cell wall appeared amorphous, while the structure was crystalline above 20% water content. The lipid bodies interassociated into membrane bilayers in seeds containing 20 to 25% water. Such lyotropic phase transitions in membrane lipids during lettuce seed hydration are believed to contribute to the biphasic freezing behavior observed in lettuce seeds at different moisture contents and to provide a natural freezing tolerance mechanism for highly desiccated plant tissues such as seeds. 相似文献
19.
Background and Aims
Most priming studies have been conducted on commercial seed lots of unspecified uniformity and maturity, and subsequent seed longevity has been reported to both increase and decrease. Here a seed lot of Digitalis purpurea L. with relatively uniform maturity and known history was used to analyse the effects of priming on seed longevity in air-dry storage.Methods
Seeds collected close to natural dispersal and dried at 15 % relative humidity (RH), 15 °C, were placed into experimental storage (60 % RH, 45 °C) for 14 or 28 d, primed for 48 h at 0, −1, −2, −5, −10 or −15 MPa, re-equilibrated (47 % RH, 20 °C) and then returned to storage. Further seed samples were primed for 2 or 48 h at −1 MPa and either dried at 15 % RH, 15 °C or immediately re-equilibrated for experimental storage. Finally, some seeds were given up to three cycles of experimental storage and priming (48 h at −1 MPa).Key Results
Priming at −1 MPa had a variable effect on subsequent survival during experimental storage. The shortest lived seeds in the control population showed slightly increased life spans; the longer lived seeds showed reduced life spans. In contrast, seeds first stored for 14 or 28 d before priming had substantially increased life spans. The increase tended to be greatest in the shortest lived fraction of the seed population. Both the period of rehydration and the subsequent drying conditions had significant effects on longevity. Interrupting air-dry storage with additional cycles of priming also increased longevity.Conclusions
The extent of prior deterioration and the post-priming desiccation environment affect the benefits of priming to the subsequent survival of mature seeds. Rehydration–dehydration treatments may have potential as an adjunct or alternative to the regeneration of seed accessions maintained in gene banks for plant biodiversity conservation or plant breeding.Key words: Digitalis purpurea, priming, re-drying, seed longevity, seed storage, ageing 相似文献20.