聚乙二醇(PEG)浸种对茎瘤芥老化种子活力及其幼苗生长的影响

Effects of PEG-Soaking on Aged Seed Vigor and Seedling Growth of Tumorous Stem Mustard (Brassica juncea var.tumida Tsen et Lee 'Yonganxiaoye')

茎瘤芥品种‘永安小叶’老化种子经聚乙二醇(PEG)浸种后,其种子活力和幼苗生长与PEG浓度有一定的相关性,不同浓度PEG浸种后的茎瘤芥种子膜透性均降低,种子发芽率、发芽势、发芽指数和活力指数增大,幼苗根干重、茎干重和根长也均增大,幼苗叶片中丙二醛(MDA)含量降低。幼苗生长与种子活力的变化趋势一致,PEG浓度小于30%时呈增大趋势,大于30%时呈减小趋势,但均大于不做PEG处理的;幼苗叶片中MDA含量与种子膜透性变化趋势一致,PEG浓度小于25%时,呈降低趋势,大于25%时则呈升高趋势,但这些指标均低于不做PEG处理的。

The relationships among seed vigor,seedling growth and polyethylene glycol （PEG） concentration were investigated after aged seeds of tumorous stem mustard （Brassica juncea var.tumida ＇Yonganxiaoye＇） soaking with PEG.The results showed that permeability of seed membranes and malondialdehyde （MDA） content in seedling leaves were both decreased.Seed vigor parameters,such as germination percentages,germination trends,germination index and vigor index were elevated.Dry weight of roots and stems,as well as root length of seedlings were all increased.Seed vigor and seedling growth displayed similar trends,which were increased under PEG concentrations less than 30% and were decreased under those more than 30%,while all parameters were larger than the control.MDA content in seedling leaves displayed similar trends with permeability of seed membranes,which were decreased under PEG concentrations less than 25% and were increased under those more than 25%,while all data were lower than the control.