不同外源生长调节剂对黄瓜镉毒害的调控作用

Regulatory Effects of Different Exogenous Growth Regulators on Cadmium Toxicity for Cucumber

以黄瓜"津研4号"为试材,采用土培试验方法,研究了外源赤霉素(GA)、柠檬酸(HCA)、褪黑素(MLT)、亚硒酸钠(Se)单施或配施对70 mg·kg-1Cd处理下黄瓜幼苗根长、株高、叶绿素含量及可溶性蛋白质含量的影响及其调控机制,以期为黄瓜的耐镉栽培提供参考依据。结果表明:镉处理会显著降低黄瓜根长、株高、叶绿素和可溶性蛋白质含量,而各类外源生长调节剂均对黄瓜镉毒害症状有所调控。外源喷施Se、GA和HCA+GA+MLT对Cd胁迫下黄瓜根长和株高生长有显著促进作用,使黄瓜幼苗根长生长基本恢复到对照水平;外源Se会显著升高黄瓜叶片叶绿素a含量、b含量、a+b总量和叶绿素a/b值,其中叶绿素b含量上升幅度最大,较单独镉处理升高52.3%;外源Se、HCA、Se+GA+MLT处理可使Cd胁迫下黄瓜可溶性蛋白质含量得到显著恢复。表明此4种外源生长调节剂在一定程度上均能调控黄瓜镉毒害,其中Se的调控作用最为明显,它对黄瓜镉毒害具有明显的缓解作用。

The cucumber variety ‘Jinyan 4’ was used as research material,the regulatory effects of different exogenous growth regulators under 70 mg？kg-1 Cd stress on root length,plant height,chlorophyll content and soluble protein content of cucumber seedlings were studied based on pot experiment,in order to provide reference basis for Cd tolerance cultivation of cucumber.The results showed that Cd treatment could significantly decrease cucumber root length,plant height,contents of chlorophyll and soluble protein,while exogenous growth regulators could regulate cucumber cadmium toxicity symptoms in different degree.Exogenous Se,GA and HCA＋GA＋MLT significantly promoted root length and height growth of cucumber under Cd stress,and the root length growth of cucumber seedlings returned to the control level.Exogenous Se significantly increased chlorophyll a content,chlorophyll b content,chlorophyll a＋b content and chlorophyll a/b value in cucumber leaves,with the largest increase value in chlorophyll b content,which increased 52.3% compared with Cd treatment alone.Exogenous Se,HCA and Se＋GA＋MLT treatments could significantly restore soluble protein content in cucumber under Cd stress.It suggested that the four exogenous growth regulators could regulate cucumber cadmium toxicity to some extent,and the regulation of Se was the most obvious,which had distinct alleviation effect on cucumber cadmium toxicity.