外源BR处理对碱性盐胁迫下辣椒生长的影响

赵恺 辛文春 何冰纾

摘要 为探究外源油菜素内酯（ Brassinolide， BR）对辣椒耐盐性的影响，以“湘研15号”辣椒为试材进行田间模拟试验，经过21 d碱性盐胁迫后，分析外源BR对辣椒幼苗植株生长情况、抗氧化酶活性、丙二醛等抗逆性相关生理指标的影响。结果表明， BR可促进盐胁迫下辣椒幼苗植株增长、提高植株干重，中浓度（0.25～0.50 mg/L）效果最为明显;盐胁迫下SOD活性增加39.82 %，BR为1.00 mg/L时SOD活性最大;盐胁迫下POD活性增加13.80 %，BR为0.50 mg/L时POD活性最大;盐胁迫下叶片CAT活性增加53.27 %，BR为0.50 mg/L时CAT 活性最大;盐胁迫下MDA 含量提高61.34 %，BR为0.50 mg/L时MDA含量最低。由此可知，在NaHCO3盐胁迫时外源喷施 BR溶液可显著减轻胁迫所带来的伤害，提高苗木的抗盐性，其中以喷施0.50 mg/L缓解效应最为显著。

关键词 油菜素内酯;盐胁迫;辣椒

中图分类号 S641.3 文献标识码 A

文章编号 0517-6611（2020）14-0029-03

doi：10.3969/j.issn.0517-6611.2020.14.009

Abstract To explore the effect of exogenous brassinolide（ BR） on salt tolerance of pepper，“Xiangyan15” was used as material for the experiment， and the materials were subjected to alkaline salt stress for 21 days.The growth of pepper， the activity of antioxidant enzymes and the changes of physiological indexes which related to stress resistance were investigated after spraying different concentrations of BR.The results showed that BR could promote the growth of plant height and dry weights accumulation of pepper seedlings under salt stress， and there were significant differences among the treatments， especially at 0.25-0.50 mg/L，the activities of SOD，POD and CAT in leaves were increased.SOD activity of leaves increased by 39.82% under salt stress，when BR was 1.00 mg/L，SOD activity was the highest;POD activity increased by 13.80% under salt stress，POD activity was the highest when BR was 0.50 mg/L;CAT activity increased by 53.27% under salt stress，when BR was 0.50 mg/L，CAT activity was the highest， and the MDA content was significantly increased by 61.34% under salt stress， and the lowest at BR was 0.50 mg/L，which was significantly different from other treatments.Based on the physiological indexes，it could be concluded that spraying extraneous BR could significantly relieve the salt injury and improve salt tolerance.Moreover， spraying extraneous BR of 0.50 mg/L had the best alleviation effect.

Key words Brassinolactone;Salt stress;Pepper

土壤鹽碱化是制约农业生产的一个重大灾害，不但能够破坏农林生产和生态环境，还危害作物的生长环境，而且阻碍农业现代化生产进程[1]。 盐胁迫下植物会受离子毒害，大量产生有毒自由基，膜脂过氧化程度加重，蛋白质降解，DNA链被破坏，导致植物生长发育受阻[2]。盐胁迫之所以能够影响植物生长体现在土壤盐分过多能造成土壤渗透势的下降，使植物吸水困难，容易形成生理性缺水;高水平下的盐溶液可吸收细胞膜上的离子，致使细胞膜结构破坏，造成有机质外渗;盐胁迫抑制植物蛋白质合成进程，加快细胞内已合成储存蛋白质的分解[3]。 植物体为适应盐胁迫会产生一系列生理变化，如生成渗透调节物质等来降低水势增加耐盐性[4-5]。……