水杨酸引发处理对低温吸胀期间玉米种子生理指标的影响

摘要

为明确水杨酸(SA)引发处理下玉米种子在低温吸胀期间生理指标的变化规律,以玉米品种郑单958种子为试验材料,用0.1 mmol/L SA引发处理玉米种子36 h,在15 ℃低温下吸胀不同时间(0、12、24、36、48 h),研究SA引发处理对玉米种子胚、胚乳及种皮在低温吸胀期间生理指标的影响.结果表明,SA引发处理显著提高玉米种子的发芽率;随着吸胀时间的延长,种子浸出液核苷酸含量呈先降低后升高的趋势,种胚可溶性糖含量呈先下降后上升的趋势,胚乳的POD活性呈逐渐上升趋势,种皮的CAT活性呈先上升后降低的趋势.与未引发种子相比,SA引发处理在大部分吸胀时间里,表现为可提高玉米种子胚乳和种皮的可溶性糖含量,增加胚、胚乳和种皮的可溶性蛋白含量,增强胚乳和种皮的CAT和POD活性,降低种子浸出液中核苷酸含量,从而增强玉米种子对低温胁迫的抵抗能力.%In order to investigate how salicylic acid(SA) priming affect the physiological indexes of maize seed(embryo,endosperm and seed coat) during seed imbibition under low temperature,maize hybrid Zhengdan 958 was used as materials in this study,and the seeds were primed with 0.1 mmol/L SA for 36 h,subsequently manipulated by imbibition duration for 0,12,24,36,48 h under 15 ℃ respectively.The results indicated that SA priming significantly increased seed germination rate.The nucleic acid content in seed leakage decreased at first and then increased with prolonged imbibition time.Similarly,the soluble sugar content of embryo decreased at first and then increased.While POD activity of endosperm gradually increased,and CAT activity of seed coat increased at first and then decreased.Compared with no primed seed,during the majority of seed imbibition time,SA priming treatment could significantly increase the soluble sugar content of endosperm and seed coat,improve the soluble protein content of embryo and seed coat,enhance the CAT and POD activity of endosperm and seed coat,decline the nucleic acid content in seed leakage,and thus strengthen the resistance of maize seed to chilling stress.