关键词: 谷子, 干旱, 复水, 苗期, 生理指标

Abstract: In order to investigate the physiological basis of variable drought tolerance in different genotypes of foxtail millet \[Setaria italica (L.) Beauv\], this paper took drought tolerant variety (Jigu 16) and drought sensitive variety (Lugu 1) as materials, and conducted pot-culture under rainproof shed experiment to study the effects of drought stress and rehydration on foxtail millet morphological characters, leaf water content, malondialdehyde (MDA) content, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT). The results indicated that along with the decreasing of soil moisture content, leaf of Lugu 1 fristly showed yellow spots then began to wilt. Drought stress made the moisture contents in leaf of 2 varieties dropped down. After rehydration, Jigu 16 rapidly recovered to the initial level compared with Lugu 1. The MDA contents in both varieties showed a significant increase after exposed to drought stress. But Lugu 1 accumulated more MDA than Jigu 16 during the entire process. The enzymatic activities of SOD, POD and CAT in 2 varieties were elevated as the drought stress progressed. The increasing range of SOD activity in Jigu 16 was higher than that of Lugu 1, but there was no significant differences between them. The POD activity of Lugu 1 showed a tendency of first increase then decrease. The CAT activity slightly increased during the entire drought stress process. There were differences in morphological characters and physiological indexes of different drought tolerant varieties. It was these differences that brought about the different drought tolerance to foxtail millet varieties with different genotypes.

Key words: foxtail millet, drought stress, rehydration, seedling stage, physiological index