By monitoring soil moisture using both soil moisture meter and soil sampling method, we evaluated the drought tolerance of maintainer lines at panicle stage. Results showed that: (1) the maintainer lines K22-B, Jin 23-B, and II-32-B were drought-insensitive at panicle stage, while Zhenshan 97-B, Zhong 9-B, and Xieqingzao-B were drought-sensitive; (2) the tested maintainer lines were more sensitive to drought stress at flowering stage (from pollen filling stage to spikelets filling stage) than at booting stage (from meiosis stage of pollen mother cell to pollen filling stage); (3) drought stress at booting stage mainly injured the spikelet fertility and there was a positive correlation between stress index and percentage of unfilled grains (r = 6988~(**)), and drought stress at flowering stage injured both the fertility and plumpness of spikelets, the percentage of unfilled grains and the percentage of non-fully filled grains exhibited a positive correlation with stress index (r = 0.7660~(**) and r = 0.5230 respectively); (4) there was no correlation between drought tolerance at panicle stage and grain setting characteristics under normal condition.%以负压式土壤湿度计和取土烘干法双重监控盆栽试验的土壤水势变化,观测我国15个常用水稻保持系的穗期耐旱性和育性特征.结果表明,K22-B、金23-B及II-32-B等保持系为穗期干旱胁迫钝感材料,而珍汕97-B、中9-B及协青早-B等为穗期干旱胁迫敏感材料;参试保持系在开花期(花粉粒充实期到小穗灌浆初期)比孕穗期(花粉母细胞减数分裂期到花粉粒充实期,15 d)对干旱胁迫更敏感;保持系孕穗期干旱胁迫主要伤害颖花育性,其胁迫指数与空壳率正相关(r=0.6988~(**)),开花期干旱胁迫不仅伤害颖花育性并影响小穗充实,其胁迫指数与空壳率正相关(r=0.7660~(**)),也与秕谷率正相关(r=0.5230);穗期耐旱性与其正常生育条件下的穗部结实性状不具直接相关性.
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