沙芥种子发育过程中的脱水耐性

以发育过程中经脱水和未脱水处理的沙芥种子为试验材料，测定了其含水量、萌发率和抗氧化酶系统，探讨了沙芥种子脱水耐性与抗氧化系统之间的关系。结果表明：在20～60DAF,沙芥种子含水量逐渐下降，干重逐渐增加；60DAF种子具有萌发能力，萌发率为24％；且脱水可促进沙芥种子的萌发，人工脱水至含水量为12％和5％时，萌发率分别为56％和44％，自然脱水至含水量为12％和5％时，萌发率分别为52％和60％；发育过程中沙芥种子SOD活性逐渐降低，而CAT、POD、LOX活性以及MDA含量均呈上升趋势；在脱水过程中，随着种子含水量的下降SOD活性逐渐降低，CAT和LOX活性逐渐升高，而POD活性呈先降低后升高的变化趋势。脱水后，种子中MDA含量均高于CK。60DAF的沙芥种子已获得脱水耐性。

Desiccation Tolerance of Pugionium Cornutum Seeds during the Development

The change of moisture contents, germination rate and antioxidant system of Pugionium cornutum seeds during the development with dehydration were measured, and the relationship between the desiccation tolerance of seeds and the antioxidant system was analyzed. The results showed that from 20 days to 60 days after flowering （DAF）, the moisture content of P.cornutum seeds decreased gradually, but the dry weight increased. At 60 DAF, the seeds could germinate and the germination rate was 24%. Dehydration enhanced the germination rate, when the moisture content of seeds decreased to 12% and 5% with silica gel dehydration, the germination rate was up to 56% and 44% respectively, and the moisture content decreased to 12% and 5% in natural, the germination rate was up to 52% and 60% respectively. The activity of superoxide dismutase （SOD） decreased gradually during the development of P cornuturn seeds, but the activity of peroxidase （POD）, catalase （CAT） and lipoxidase （LOX） increased, and the content of malondialdehyde （MDA） increased. With declining of the moisture content in the dehydration process, the MDA content in seeds increased, while the activity of SOD decreased, the activity of CAT and LOX increased, but the activity of POD decreased first and then increased. The P.cornutum seeds have acquired desiccation tolerance at 60 DAF.