摘要
以老芒麦(Elymus sibiricus)种子为材料,通过控制劣变和PEG引发处理(PEG-5%、PEG-10%和PEG-20%),研究比较未劣变(CK)和劣变14天(D14)种子发芽特性和吸胀过程(未吸胀、6、72和144 h)中抗氧化指标的变化.结果表明,与CK相比,D14种子的发芽能力降低,幼苗生长受到抑制.PEG-10%引发处理显著提高劣变种子的发芽势、发芽率和发芽指数,以及幼苗的根长、苗长、根重和苗重,同时也显著提高了劣变种子在未吸胀时的AsA含量、吸胀6 h时的GSH含量、吸胀72 h时的GR活性和吸胀144 h时的POD活性,降低了吸胀6 h和72 h时的H2O2含量和吸胀144 h时的MDA含量,可以有效保持种子正常的萌发过程.通过聚类分析发现,可以将9个抗氧化防御系统指标分为3组,其中MDA含量、POD和SOD活性在不同吸胀时间的变化趋势一致.
Abstract
In this study,siberian wildrye(Elymus sibiricus)seeds were used as materials to compare the germination characteristics and changes in antioxidant indexes during imbibition process(beginning,6 h,72 h,and 144 h)between non-deteriorated(CK)and deteriorated(D14)seeds under controlled dete-rioration and polyethylene glycol(PEG)priming treatments(PEG-5%,PEG-10%,and PEG-20%).Results indicated that compared to CK,the seed germination of D14 was reduced and the seedling growth was inhibited.PEG-10%priming significantly enhanced the germination potential,germination percent-age,germination index,radicle length,seedling length,radicle weight,and seedling weight of deteriorated seeds.Additionally,PEG-10%priming significantly increased the ascorbic acid(AsA)content at begin-ning of imbibition,glutathione(GSH)content at 6 h of imbibition,glutathione reductase(GR)activity at 72 h of imbibition,and peroxidase(POD)activity at 144 h of imbibition,while reduction of hydrogen per-oxide(H2O2)levels at 6 h and 72 h of imbibition and malondialdehyde(MDA)content at 144 h of imbibi-tion were observed.Changings on antioxidant indices can effectively maintain the normal germination pro-cess.In cluster analysis,it was found that the nine antioxidant defense system indicators could be roughly clustered into 3 groups,among which the MDA content,POD activity,and superoxide dismutase(SOD)activity follow the same variation trend at different imbibition times.
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