Water Status Changes During Development in Relation to the Germination and Desiccation Tolerance of Aesculus hippocastanum L. Seeds

Seed growth characteristics of Aesculus hippocastanum were examinedin detail during development from about 70 to 140 d after anthesis(DAA), mainly in 1988 and 1989. Mean fresh and dry weights increasedfor both the axis and the whole seed up to the time of peakseed fall at 135 DAA with no cessation before fruit abscission.Water per seed increased up to 100 DAA, after which no furtherincrease occurred; moisture content declined for the embryonicaxis and whole seed respectively from above 75 and 65% at 95DAA to 65 and 50% at 130 DAA. At fruit shedding in 1990 waterpotential values of -1·2, -2·6 and -1·1MPa were observed for the testa, cotyledon and axis tissuesrespectively; relevant sorption isotherms are presented. Decreases in seed moisture content during development were accompaniedby increases in desiccation tolerance and in germinability,both reaching their maximum at the time of peak seed fall. Atmaturity, only about 10% viability was retained on drying seedto 20% moisture content; it is confirmed that the seeds are'recalcitrant'. The exact relationship between moisture contentand germination during development was dependent on the deptof dormancy, as judged by the period of chilling required; eachduration of chilling at 2°C within the range 3-12 weeksyields a curve of sigmoid shape. No germination occurred at26°C without chilling, but nearly full germination can beobserved for samples collected at 6 weeks before maximum seedfall with 12 weeks chilling. The rate of moisture loss duringdesiccation at 15°C and 15% rh becomes reduced during development.The ontogeny of these 'recalcitrant' seeds is compared withthat of 'orthodox' seeded species and the implication of sigmoid-shapedcurves for the relationship between seed moisture content andgermination are considered.Copyright 1993, 1999 Academic Press Aesculus hippocastanum L., horse chestnut, seed development, water status, germination, desiccation intolerance, desiccation rate     

The Effect of Desiccation on the Longevity of Seeds of Araucaria hunsteinii and A. cunninghamii

Seeds of Araucaria hunsteinii K. Schum. dried quicker at 29°Cthan at 19°C and quicker with the seed-coat removed thanwhen intact; seeds enclosed in polyethylene bags increased inmoisture content. At 15°C, seeds in a flow of air driedquicker than seeds in a box with silica gel, which in turn driedquicker than seeds in a box with no desiccant. No loss of germinationability occurred on drying fresh seed from 53 to about 32 percent moisture content (fresh weight basis); during further desiccationthe percentage germination was related to percentage moisturecontent in the form of a sigmoid curve, culminating in a completefailure to germinate at approximately 14 per cent moisture content.A consistent relationship was observed for all treatments andthe mean critical moisture content for seed death (failure togerminate) was near 23 per cent. Excised embryos grew on 1 percent agar but died if previously subjected to 14 h of desiccationat 15°C. In contrast, no relationship was found between germination andmoisture content of A. cunninghamii D. Don on desiccation from21 to 7 per cent moisture content. Possible causes for the observeddifference in response to desiccation are discussed and methodsfor seed storage are considered. Araucaria hunsteinii, Klinkii pine, Araucaria cunninghamii, Hoop pine, desiccation, seed longevity, storage of seeds     

An Intermediate Category of Seed Storage Behaviour?: I. COFFEE

Seeds of four cultivars of arabica coffee (Coffea arabica L.)were tested for germination following hermetic storage for upto 12 months at several different combinations of temperaturesbetween –20 °C and 15 °C and moisture contentsbetween 5% and 10% (wet basis). Most of the seeds from one cultivarwithstood desiccation to between 5% and 6% moisture content,a seed water potential of approximately –250 MPa, butthose of the remaining three cultivars were much more sensitiveto desiccation damage. Moreover, in all four cultivars, seedlongevity at cool and sub-zero temperatures, and at low moisturecontents did not conform with orthodox seed storage behaviour:viability was lost more rapidly under these conditions thanat either warmer temperatures or higher moisture contents. Theresults confirm that coffee seeds fail to satisfy the definitionsof either typical orthodox or recalcitrant seed storage behaviour.These results, therefore, point to the possibility of a thirdcategory of storage behaviour intermediate between those oforthodox and recalcitrant seeds. One of the main features ofthis category is that dry seeds are injured by low temperatures. Key words: coffee, Coffea arabica L., seed storage, seed longevity, desiccation, temperature     

Desiccation Tolerance and Potential Longevity of Developing Seeds of Rice (Oryza sativa L.)

The longevity and desiccation tolerance of samples of seedsof a japonica rice (Oryza sativa L.) harvested serially duringdevelopment from plants grown in two temperature regimes, viz28/20 °C and 32/24 °C (12/12 h) were determined. Massmaturity (defined as the end of the seed-filling phase) occurred19·7 and 18·3 d after 50% anthesis, respectively.Longevity (determined at 40 °C with 15% moisture contentand quantified by the value of the constant K_i of the seed viabilityequation) improved during seed development and maturation until17 and 14 d after mass maturity in the cooler and warmer regimes,respectively, but declined thereafter. Changes in K_i with timewere similar in the two environments until mass maturity, butthe increase in K_i values after mass maturity was much greaterin the cooler regime. Tolerance of desiccation to low (4%) moisturecontents improved until 22 and 14 d after mass maturity in thecooler and warmer regimes, respectively, when maturation dryinghad reduced seed moisture contents naturally to 24 and 32% moisturecontent, respectively. Further delays to seed harvest reduceddesiccation tolerance, particularly in the warmer environment.Comparison among 15 samples of seeds harvested at differenttimes in the two environments showed a strong correlation (r= 0·947, P < 0·01) between longevity (K_i) anddesiccation tolerance (to 4% moisture content). Hence, it issuggested that the regulation of desiccation tolerance to lowmoisture contents and potential air-dry longevity during seeddevelopment and maturation determined here may have a commoncause.Copyright 1994, 1999 Academic Press Oryza sativa L., rice, desiccation tolerance, genebanks, seed development, seed longevity, temperature     

Moisture Content and the Longevity of Seeds of Phaseolus vulgaris

The lower limit to the negative logarithmic relation betweenseed longevity and moisture was determined in bean (Phaseolusvulgaris L.). Sub-lots of seed were hermetically stored at 65°C and 11 moisture contents (3.26–13.6% f. wt) forup to 80 d, tested for germination and the seedlings evaluated.In accordance with the seed viability equation, there was anegative logarithmic relation between moisture content (%, f.wt) and longevity. Two different criteria for estimating theslope constant of this relation gave similar values of 4.76(s.e. 0.26) and 4.82 (s.e. 0.24). The calculated lower moisturecontent limits to the relation were 5.7 and 5.6%, respectively,values at equilibrium with 10.6–10.8% relative humidity(rh). Further drying to 3.26% had little additional effect onlongevity, but initial germination was slightly reduced. Theresults are discussed in relation to water potential and comparedwith other crops. Arguments against transforming germinationvalues to disregard the seeds initially failing to germinateare emphasized. Common bean, Phaseolus vulgaris L. cv. Provider, seed storage, seed longevity, seed moisture, viability equation, water relations     

The Effect of Moisture Content on the Low Temperature Responses of Araucaria hunsteinii Seed and Embryos

The effect of moisture content on the low temperature responsesof 'recalcitrant' Araucaria hunsteinii seed and excised embryoswas investigated in relation to germination and storage. At6°C seed longevity was decreased as mean moisture contentwas reduced from 45 to 30% (fresh weight basis); the time predictedfor the loss of one probit of germination,     

Theoretical Basis of Protocols for Seed Storage III. Optimum Moisture Contents for Pea Seeds Stored at Different Temperatures

In previous work, we demonstrated that there was an optimummoisture level for seed storage at a given temperature (Vertucciand Roos, 1990), and suggested, using thermodynamic considerations,that the optimum moisture content increased as the storage temperaturedecreased (Vertucci and Roos, 1993b). In this paper, we presentdata from a two year study of aging rates in pea (Pisum sativum)seeds supporting the hypothesis that the optimum moisture contentfor storage varies with temperature. Seed viability and vigourwere monitored during storage under dark or lighted conditionsat relative humidities between 1 and 90%, and temperatures between-5 and 65°C. The optimum moisture content varied from 0·015g H₂O g^-1 d.wt at 65°C to 0·101 g H₂O g^-1 d.wt at15°C under dark conditions and from 0·057 at 35°Cto 0·092 g H₂O g^-1 d.wt at -5°C under lighted conditions.Our results suggest that optimum moisture contents cannot beconsidered independently of temperature. This conclusion hasimportant implications for 'ultra-dry' and cryopreservationtechnologies.Copyright 1994, 1999 Academic Press Seed storage, seed aging, seed longevity, water content, temperature, glass, desiccation damage, ultradry, Pisum sativum L., pea, cryopreservation     

Survival and Vigour of Lettuce (Lactuca sativa L.) and Sunflower (Helianthus annuus L.) Seeds Stored at Low and Very-low Moisture Contents

Seeds of lettuce (Lactuca sativa L.) and sunflower (Helianthusannuus L.) were stored hermetically at 35 °C with 11 differentmoisture contents between 1·3 and 6·9%, and between1·3 and 7·1% of fresh mass, respectively. Germinationand vigour (mean germination time, root length, seedling dryweight) were determined after storage for 0, 8, or 16 weeks(sunflower) or 0, 8, 16, or 48 weeks (lettuce) in these environmentsfollowed by various humidification treatments (to avoid imbibitioninjury). The range of seed storage moisture contents over whichdeterioration was minimized depended upon the criterion of deteriorationused, and varied somewhat between species. Comparison of theseranges for seeds stored for the longest durations showed thatfor some criteria seed performance was poorer (P < 0·05)at both the lowest and highest moisture contents investigatedthan at certain of the intermediate storage moisture contents(e.g, most rapid germination occurred in sunflower followingstorage at 2·2-4·7% moisture content), whereasfor other criteria all the drier storage moisture contents weresuperior to the more moist (e,g. greatest seedling growth occurredin sunflower following storage at 1·3-5·1% moisturecontent). But none of these results suggested that lettuce andsunflower seeds stored hermetically at 2·5-3·0%or 2·2-2·5% moisture content, respectively, wereless vigorous than at any other moisture content tested. Inboth species, these storage moisture contents are in equilibriumwith about 8-10% relative humidity (r.h.) at 20 °C, whichis similar to and indeed marginally less than the 10-13% r.h.recommended following earlier studies on the longevity of seedsin hermetic storage at much warmer temperatures. Thus, theseresults show no evidence that the optimum seed moisture contentfor storage increases with decrease in temperature, at leastover the range 35-65 °C, as has been suggested elsewhere.We conclude that the international recommendation for the long-termseed storage for genetic conservation at 5 ± 1% moisturecontent should not be revised upwardly, and that in situationswhere refrigeration cannot be provided storage at even lowermoisture contents is worthy of further investigation for thoseseeds in which desiccation at 20 °C to equilibrium at 10%r.h. results in moisture contents well below 5%.Copyright 1995,1999 Academic Press Helianthus annuus L., sunflower, Lactuca sativa L., lettuce, desiccation, seed storage, seed vigour     

Effects of Moisture Content on Germination of Seeds of Hancornia speciosa Gom. (Apocynaceae)

Seeds of Hancornia speciosa germinated best at a temperatureof 20–30 °C. The viability of the seeds during storagewas short and the best storage conditions for viability entailedkeeping the seeds in polyethylene bags. Seed viability was maintainedonly when the seeds were stored at a moisture content above30%; storage conditions which allowed dehydration resulted ina rapid loss of viability (the seeds showed recalcitrant behaviour). Low temperature during storage did not improve longevity. Arelationship between germination and moisture content was established,but when the moisture content fell below 25% there was a drasticreduction of germination. After 9 weeks of storage, even athigh moisture content, seeds lost viability. Loss of seed viability during seed dehydration was associatedwith increased leakage of electrolytes and organic solutes,and reduced tetrazolium staining during subsequent imbibition. Hancornia speciosa, germination, recalcitrant seeds, storage, moisture     

Responses to Drying of Recalcitrant Seeds of Quercus nigra L.

It has been suggested that rate of desiccation can influencethe expression of recalcitrant behaviour in seeds, thus complicatingthe task of determining which seeds are truly recalcitrant.The objective of this study was to see if variable rates ofdesiccation influenced such behaviour inQuercus nigra L., atree seed known to be recalcitrant. Acorn moisture content, leachate conductivity, and germinationwere determined at various times during desiccation at threerates at 27 and 40°C. Moisture contents and germinationdecreased as the severity of desiccation increased. Leachateconductivity increased slightly but was not a sensitive indicatorof loss of viability. The critical (lethal) moisture contentfor these acorns was 10–15%, although rehydration within48 h of reaching this level prevented death in about 25% ofthe acorns. At 27°C any desiccation treatment that producedlosses of 30–50mg of moisture per g of acorn dry weightper day should be suitable as a test for recalcitrance in thegenus. Apparent physiological or fungal damage at 40°C rulesout the higher temperature for such a test. Quercus nigra L.; desiccation rate; temperature; recalcitrant; leachate conductivity; germination; viability     

Desiccation Intolerance in Seeds of Zizania palustris is Not Related to Developmental Age or the Duration of Post-harvest Storage

Freshly harvested seeds of Zizania palustris L. representingfour distinct stages of development were intolerant of desiccation.Rapid drying did not improve survival. The relationship betweenprobit viability and embryo moisture content for freshly harvestedmature seeds was identical to that described in an earlier publicationfor seeds previously stored fully imbibed at low temperaturesto remove dormancy. A small reduction in embryo moisture contentduring the first 3 d of drying at 15% r.h. and 15°C ledto a highly sigificant (P < 0.01) increase in the proportionof fresh seeds capable of germination in response to a rangeof dormancy breaking factors including giberellins. Resultsare discussed in relation to previous work on recalcitrant seedsand to the widely reported developmental changes in orthodoxseeds which are triggered by desiccation. Zizania palustris, wild rice, seeds, drying, desiccation intolerance, development     

Prehydration and Priming Treatments that Advance Germination also Increase the Rate of Deterioration of Lettuce Seeds

The influence of prehydration in water or priming in –1.5 MPa polyethylene glycol 8000 solution for various periods,followed by redrying, on germination rate and longevity of lettuce(Lactuca sativa L.) seeds (achenes) was determined during controlleddeterioration at 10% moisture content (fresh weight basis) and40°C. Short prehydration treatments (up to 1 h) had littleeffect on either germination rate or longevity, but significantlyimproved root growth rates. Increasing durations of prehydrationor priming reduced the mean time to germination by up to 61%relative to untreated seeds, but also reduced mean seed longevityby as much as 84% Prehydration and priming altered the relationshipsbetween germination rate and viability and between normal andabnormal seedlings during ageing. Prehydration in abscisic acidor at a temperature inhibitory to germination did not preventthe reduction in longevity under controlled deterioration conditions.While prehydration or priming treatments effectively acceleratesubsequent germination rates of lettuce seeds, the redried seedsare nonetheless highly susceptible to deterioration in storage. Key words: Lettuce, Lactuca sativa L., seed priming, seed deterioration, germination rate     

Recalcitrant Seed Storage Physiology in Three Aquatic Grasses (Zizania palustris, Spartina anglica and Porteresia coarctata)

The moisture content/probit viability relationship for storedseeds of Zizania palustris L. and Spartina anglica C. E. Hubbardwas linear and independent of the rate of embryo drying. Theseresults provide firm evidence of recalcitrant storage physiologyin these taxa. Preliminary tests strongly suggest that freshseeds of Porteresia coarctata (Roxb.) Tateoka are also intolerantof desiccation In Z. palustris apparent differences in desiccation tolerancebetween individuals can be partly explained by wide variationin individual embryo moisture contents during desiccation. Long-termstorage experiments in solutions of polyethylene glycol 6000(PEG) suggest that the actual variation in desiccation toleranceis confined to a narrow range of embryo water potentials inthe range –2 to –3 MPa. Despite the presence of prolonged dormancy in seeds of Z. palustrisand S. anglica there is no evidence of a significant effectof dormancy or storage period (up to the point of visible germination)on the limits of desiccation tolerance Aquatic grasses, seeds, storage, desiccation intolerance     

The Survival of Germinating Orthodox Seeds after Desiccation and Hermetic Storage

Seeds of barley (Hordeum vulgare L.) and mung bean (Vigna radiata(L.) Wilczek), with orthodox seed storage behaviour, were imbibedfor between 8 h and 96 h at 15 °C and 25 °C, respectively,while barley seeds were also maintained in moist aerated storageat 15 °C for 14 d. These seeds and seedlings, together withcontrols, were then dried to various moisture contents between3% and 16% (wet basis) and hermetically stored for six monthsat —20°C, 0°C or 15°C. In both species, neitherdesiccation nor subsequent hermetic storage of the control lotsresulted in loss in viability. The results for barley seedsimbibed for 24 h were similar to the control, but desiccationsensitivity increased progressively with duration of imbibitionbeyond 24 h in barley or 8 h in mung bean; these treatmentsalso reduced the longevity of the surviving seeds in air-drystorage. Loss in viability in barley imbibed for 48 h was mostrapid at the two extreme seed storage moisture contents of 3·6%and 14·3%, and in both these cases was more rapid at15 °C than at cooler temperatures. Similarly, for mung beanimbibed for 8 h, loss in viability was most rapid at the lowest(4·3%) moisture content, but in this case it was morerapid at –20 °C than at warmer temperatures. Thus,these results for the storage of previously imbibed orthodoxseeds conform with the main features of intermediate seed storagebehaviour Key words: Barley, Hordeum vulgare L., mung bean, Vigna radiata (L.) Wilczek, desiccation sensitivity, seed longevity, seed storage behaviour     

Seed development and maturation in Phaseolus vulgaris I. Ability to germinate and to tolerate desiccation

The onset and development of both the ability to germinate andto tolerate rapid enforced desiccation were investigated duringthe development and maturation of seeds of bean (Phaseolus vulgahsL.) at different temperatures and also after different slow-dryingtreatments. The onset of germinability occurred when seeds wereless than half-filled in the absence of both a post-ovule abscissionprogramme and water loss from the seeds. Maximum ability togerminate normally and maximum tolerance to rapid enforced desiccationto 14–16% moisture content did not occur until 2–23d and 6–23 d after mass maturity (end of the seed-fillingperiod), respectively. The slow-drying of immature seeds for7 d ex planta before rapid enforced desiccation increased theability to germinate and stimulated the onset of desicationtolerance. Holding seeds moist for 7 d (during which time moisturecontent declined by <5%) had similar effects, but seed germinationafter rapid enforced desiccation was consistently greater inseeds first dried slowly than held moist. Comparisons betweenseeds less than half-filled dried slowly ex planta and fullseeds undergoing maturation drying in planta showed that a similar(slow) rate of water loss over a 7 d period had a similar effecton the subsequent ability of seeds to tolerate rapid enforceddesiccation. Thus, neither a post-ovule abscission programmenor loss of water were required for the onset of the abilityto germinate in developing bean seeds, but both were requiredfor the development of the ability to germinate and resistanceto solute leakage, when rehydrated, after rapid enforced desiccation. Key words: Bean, Phaseolus vulgaris L., seed germination, seed development, desiccation tolerance     

Storage Behaviour of Salix alba and Salix matsudana Seeds

Effects of dehydration, storage temperature and humidificationon germination of Salix alba andS. matsudana seeds were studied.Newly released seeds showed 100% germination before and afterdehydration to 11–12% moisture content. Germination ofthe high vigour lot (100% initial normal germination) was notaffected by dehydration to 6.7% moisture content but germinationdecreased with further dehydration to 4.3%. The lower vigourlot (75% initial normal germination) was more susceptible todehydration and germination decreased following dehydrationto 6.7% moisture content. Dry seeds of both species survivedimmersion in liquid nitrogen without loss of viability. Thegermination of seeds stored with 9% moisture content decreasedto 35–40% in 5 months at -20°C or in 2 months at 5°C.However, at 25°C seeds entirely lost viability within 2weeks. Seeds showed improved performance when stored at -70°C> - 20°C > 5°C > 25°C and tolerated dehydrationto a moisture content in equilibrium with 15% relative humidity.Results suggest that they are orthodox in storage behaviouralthough they are short-lived. Humidification treatment of lowvigour seed lots resulted in a remarkable increase in germinationpercentage. Copyright 2000 Annals of Botany Company Salix alba, Salix matsudana, willow, seed storage behaviour, dehydration, humidification, cryopreservation     

Seed Maturity and the Effects of Different Drying Conditions on Desiccation Tolerance and Seed Longevity in Foxglove (Digitalis purpurea L.)

The effects of different drying methods on desiccation toleranceand longevity in seeds of foxglove (Digitalis purpurea L.) wereassessed from just prior to mass maturity (when seeds have attainedmaximum dry weight), and at intervals during the post-abscissionphase of development. Tolerance of drying under seed conservationconditions (15% relative humidity, RH, and 15 °C), was acquiredclose to mass maturity at 36 d after flowering (DAF). Increasesin desiccation tolerance were induced when drying was delayedfor 4 d by placing seeds in a near-saturated atmosphere (approx.100% RH), or if seeds were pre-dried for 7 d at either approx.32% or approx. 73% RH. Irrespective of the drying treatment, seed longevity increasedthroughout the sampling period, i.e. beyond the point of massmaturity and throughout the post-abscission phase, up to thepoint of incipient natural dispersal. At each developmentalstage, delayed drying or pre-drying led to an increase in seedlongevity under controlled ageing conditions compared with seedsdried directly under seed conservation conditions. Increasesin longevity were apparent as increases in the estimates forthe intercept of transformed seed survival curves (K_i) and forthe standard deviation of the normal distribution of seed lifespans,and also in the mean time to death of individuals in storage,consistent with a continuation of ripening events. The results are discussed in relation to the assessment of seedlongevity and to current post-harvest drying practices for seedsintended for long-term ex-situ conservation.Copyright 1995,1999 Academic Press Digitalis purpurea L., foxglove, seed development, seed drying, seed longevity     

Effects of Desiccation and Cryopreservation on the In Vitro Viability of Embryos of the Recalcitrant Seed Species Araucaria hunsteinii K. Schum

Embryos excised from fresh seed had a moisture content of about37% (fr. wt.), 7% above that of the whole seed: mainly as aresult of the dryness of the seed coat. When cultured for 14d at 26°C embryo growth ranged from unorganized to fullyorganized. Embryos which had been directly surface-sterilizedexhibited lower fully organized growth than aseptically excisedembryos. During desiccation of the whole seed at 15°C and 15% r.h.moisture loss from the embryo was slow until the embryo reacheda mean critical moisture content for fully organized growthin vitro of about 30%. After this point the rate of moistureloss increased, quickly diminishing the moisture content differentialbetween the embryo and the whole seed. No such shoulder in theembryo desiccation curve was observed when using a low viability(7%) seed batch. When dried below 30% moisture content, suchaseptically excised embryos increasingly exhibited unorganizedgrowth in vitro, with only root meristem survival (46%) at 13%moisture content. In contrast, a much higher level of root meristem survival (84%of control) was observed when aseptically excised embryos wererapidly desiccated to 13% moisture content, using a flow ofsterile air. However, the benefits of rapid drying were lostif the embryos were directly surface-sterilized prior to desiccation.Furthermore, 80% of aseptically excised embryos which survivedrapid desiccation to 20% moisture content exhibited root meristemsurvival following subsequent cryopreservation. These findingshave implications for the in vitro conservation of recalcitrantseed tissue. Key words: Araucaria hunsteinii K. Schum., recalcitrant seed embryo, desiccation, cryopreservation     

An Intermediate Category of Seed Storage Behaviour?II. EFFECTS OF PROVENANCE, IMMATURITY, AND IMBIBITION ON DESICCATION-TOLERANCE IN COFFEE

Seeds of four cultivars of arabica coffee (Coffea arabica L.)received from three continents survived desiccation to between7-2% and 11-3% moisture content (wet basis), i.e. to seed waterpotentials of –90 MPa to –150 MPa, but further desiccationreduced germination (criterion, normal seedling development)in all seed lots. Only a few individuals from four of the lotsgerminated after being dried to 4–5% moisture content.Differences in desiccation sensitivity were apparent among lotswithin each cultivar. Desiccation sensitivity in these lotswas similar to that observed in seeds of orthodox species whichhave begun to germinate. Seeds extracted from fruits of intermediatematurity (yellow) were able to tolerate greater desiccationthan those from either ripe (red) or immature (green) fruits.Imbibed storage increased desiccation sensitivity. The resultsare compatible with the view that arabica coffee seeds are unableto tolerate extreme desiccation because germination has beeninitiated before harvest.     

Polypeptide markers for low temperature stress during seed germination in sunflower

Sunflower seeds behaved as chilling and freezing sensitive and also exhibited acclimation under low seed moisture content (< 1 %). At high seed moisture content (approx. 22 %) they tolerated chilling stress but failed to acclimate under freezing temperatures. Pre-imbibitional chilling (5 °C) or freezing (−5 or −10 °C) stress significantly enhanced total soluble protein (TSP) content. Chilling treatment after imbibition (in contrast to pre-imbibition) enhanced germination and this was accompanied by increase in 30, 24 and 21.9 kDa TSPs content (3 d after germination). Freezing at −5 and −10 °C suppressed seed germination and increased content of 78 and 56.2 kDa wall bound proteins. Chilling acclimation decreased 35.4, 33.9, 29.5, 23.4 and 21.4 kDa TSPs.