PEG-6000引发对老化大豆种子膜透性及保护性酶活性的影响

摘要

After the seeds of 3 soybean varieties, Heizhenzhu, Jindou 19,Jinda 74 were artificially aged under the air tight condition of high temperature( (48 ± I) ℃) and high humidity( 100% relative humidity ) , then primed by 10% ,20% and 30% PEG-6000, variation of membrane permeability and the activities of protection enzymes were tested. The results showed that relative electrical conductivity of treated seeds decreased and then increased at first and subsequently decreased and rose again with extension of aging time;MDA content decreased continuously. POD activity declined at first slowly, then increased, finally declined rapidly; SOD activity rose slowly at first and then rapidly declined. After seeds aged of 3 soybean varieties were primed with different concentration PEG-6000, the membrane permeability and MDA conent reduced relatively, and the activities of protection enzymes raised. It suggested that seed resistance to abiotic stress was enhanced. In particular, after the seeds with aging slightly were primed by 20% and 30% PEG-6000,abilities of resistance to aging were significantly enhanced.%以3个大豆品种黑珍珠、晋豆19和晋大74种子为试材,在高温((48±1)℃)、高湿(100％相对湿度)、密闭条件下对种子进行老化处理,再分别用10％,20％和30％的PEG-6000进行引发,然后测定各处理种子的膜透性及保护酶活性.结果表明,随着老化时间的延长,3个大豆品种种子浸泡24 h时的相对电导率均呈先下降后上升随后又下降上升的趋势；种子MDA含量逐渐上升；种子过氧化物酶(POD)活性呈先缓慢下降后缓慢升高再快速下降的趋势,超氧化物歧化酶(SOD)活性均呈先缓慢升高后快速下降的趋势.3个品种种子用不同浓度PEG-6000引发后,种子膜透性和MDA含量相对降低,保护酶活性提高,增强了种子抗性；尤其用20％和30％的PEG-6000引发后,当老化程度不是很严重时,可有效提高大豆种子的抗老化能力.