脱叶剂对棉花抗氧化酶及内源激素的影响

为了筛选出适宜的脱叶剂喷施时间及脱叶效果较好的脱叶剂，研究了大田条件下脱叶剂喷施时间及脱叶剂种类对棉花叶片内源激素含量、抗氧化酶活性及丙二醛含量的影响，并探讨了脱叶剂对棉花生理效应的影响。采用裂区试验设计，以脱叶剂喷施时间为主区，脱叶剂种类为副区进行试验。结果表明:喷施540 g/L脱吐隆悬浮剂（主要成分为18%噻苯隆和36%敌草隆）及5.5%噻苯隆悬浮剂后，棉花叶片中脱落酸（ABA）含量及超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性均呈先升高后降低的趋势，丙二醛（MDA）含量升高，生长素（3-吲哚乙酸，IAA）含量下降，其中脱吐隆对叶片膜系统破坏严重；在棉花吐絮率为50%时喷施540 g/L脱吐隆悬浮剂，25 d后棉花脱叶率和吐絮率分别可达90.1%和99.9%。

Effect of defoliants on antioxidative enzyme activity and endogenous hormone contents of cotton

In order to select the suitable leaf removal agent for the time and the effect of leaf removal, the effects of different time of leaf and leaf removal agent on endogenous hormone content, antioxidant enzyme activity and malondialdehyde (MDA) content in cotton leaves under field conditions were studied, and the effects of the leaf removing agents on the physiological effects of cotton were addressed as well. Using the split plot experiment design, the main area of the time of the leaf removal agent was sprayed, and the types of the leaf removal agent were tested. The result showed that after spaying the treatment of 540 g/L dropp ultra (mainly components 18% thidiazuron and 36% diuron) and 5.5% thidiazuron suspending agent, the content of abscisic acid (ABA) and superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity in cotton leaves increased at first and then decreased, the content of MDA increased and indole-3-acetic acid (IAA) content decreased, in which the dropp ultra on membrane system severely damaged. Spaying the treatment of 540 g/L dropp ultra when the cotton boll opening rate reaches 50%, cotton defoliation rate and boll opening rate can reach 90.1% and 99.9% respectively after 25 days.