关键词: 玉米, 盐胁迫, 外源生长调节物质, 种子萌发, 缓解效应

Abstract: Salt stress inhibited crop seed germination, and became the major restriction factor for crops production. In order to explore the mitigative effect of exogenous growth regulators on salt stress and relative mechanism, this paper studied the effect of salt stress on germination of maize seed, and discussed mitigative effect and physiology mechanism of exogenous growth regulator \[γ-aminobutyric acid (GABA), gibberellin (GA3), kinetin (KT), salicylic acid (SA)\] on salt stress taking Xianyu 335 as experimental material. The results showed that: ① the maize seed germination rate decreased, but water uptake rate, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased first and then decreased. All the parameters reached the highest value under 70 mmol/L treatment of salt stress. On the contrary, the contents of malondialdehyde (MDA), soluble protein, soluble sugar and Na+ were gradually increased. ② The exogenous growth regulators could effectively mitigate salt stress and significantly improved seed germination rate, defence enzyme activity, increase contents of K+, Ca2+, Mg2+, and decreased the contents of Na+ and MDA. The exogenous growth regulators could improve salt-tolerant ability of maize, especially GA3 and GABA had performed the optimum effect in mitigating salt stress.

Key words: maize, salt stress, exogenous growth regulator, seed germination, mitigative effect