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

摘要： 为了探讨不同基因型谷子品种耐旱性差异的生理基础，以耐旱谷子品种济谷16和旱敏感谷子品种鲁谷1号为材料，采用旱棚盆栽试验，研究了干旱胁迫和复水对谷子形态性状、叶片含水量、丙二醛（MDA）含量、超氧化物歧化酶（SOD）、过氧化物酶（POD）以及过氧化氢酶（CAT）的影响。结果表明：随着土壤含水量的下降，鲁谷1号叶片首先出现黄色斑点并开始萎蔫。干旱胁迫导致2种谷子的叶片含水量下降，复水后济谷16较快地恢复到对照水平；二者的MDA含量在干旱胁迫后显著增加，鲁谷1号的MDA含量在整个胁迫过程中都高于济谷16。2种谷子的抗氧化酶SOD、POD、CAT活性均随着干旱胁迫程度的加重而增加。济谷16 SOD活性增加的幅度比旱敏感谷子品种鲁谷1号高，但差异并不显著；鲁谷1号POD活性在干旱胁迫的过程中先上升后下降；CAT活性在干旱胁迫过程中略有上升。不同耐旱性谷子品种的形态性状、生理指标存在差异，这些差异造成不同基因型品种的耐旱能力不同。

关键词: 谷子, 干旱, 复水, 苗期, 生理指标