Abstract: Breeding for droughttolerant millet variety is the most important way to alleviate yield reduction caused by drought stress. Drought resistance of 7 millet hybrids and their parents was evaluated by investigating and testing their relative water content (RWC) of plants dug out from the soil after 12 h, and their root top ratio (R/T) in jointing stage, early heading stage and peak flower stage, and their drought resistance index (DI) of yield. The results showed that under drought stress conditions, Changzagu 466, Changzagu 333 and 17-400 had higher average value of RWC after plant leaving soil for 12 h in different growth stages. They were 5690%, 5452% and 5427%, respectively. Under drought stress conditions, 17-400, Changzagu 333, and Changzagu 281 had higher average value of R/T. They were 0223, 0218 and 0217, respectively. Changzagu 466 had the smallest difference value of R/T between treatments of drought stress and CK(D) in three growth stages. The average value of D was 0015. Changzagu 281 and 17-400 came the second. The average value of D of them were 0031and 0032, respectively. The value of D of male parents were basically consistent with their hybrids (correlation coefficient was 0818 5). Changzagu 466 had the highest drought DI. The DI value was 1019. Moderate drought resistant hybrids were 17-400, Changzagu 281 and Changzagu 333. There was certain correlation between the drought resistance of hybrids and their male parents. These findings provided a theoretical basis and guidance recommendations for breeding of droughtresistant millet hybrids.

Key words: foxtail millet, hybrid, water retaining capacity, root top ratio, drought resistance index

摘要：

培育抗旱品种是降低干旱导致减产的最重要途径。为评价7个谷子杂交种及其亲本的抗旱性，调查并检测谷子植株在拔节期、抽穗前期、盛花期3个时期离土12 h的相对含水量（relative water content, RWC)、根冠比（root top ratio, R/T）、产量的抗旱指数（desiccation index, DI）等指标。结果表明：干旱胁迫条件下，长杂谷466、长杂谷333和17-400在植株离土12 h后不同时期的RWC均值都较高，分别为5690%、5452%和5427%。在干旱胁迫下，17-400、长杂谷333和长杂谷281的R/T平均值较大，分别为0223、0218和0217。杂交种在3个生育时期根冠比（R/T）在干旱胁迫处理与对照处理的差值(D)幅度最小的为长杂谷466，D值平均为0015，其次是长杂谷281和17-400，D值平均为0031和0032；父本的D值幅度基本与其杂交种的D值幅度一致（相关系数为0818 5）。小区产量抗旱指数最高的杂交种为长杂谷466，DI值为1019，抗旱级别为强，抗旱性级别中等的杂交种有17-400、长杂谷281、长杂谷333。杂交种的抗旱性与父本的抗旱性有一定相关关系。研究结果为抗旱谷子杂交种选育提供一定的理论依据。

关键词: 谷子, 杂交种, 保水力, 根冠比, 抗旱指数