中文摘要：

【目的】利用一套表观性状显著差异的籼稻近等基因系,在研究花期干旱胁迫对育性影响的基础上,研究其水分和光合生理响应过程。分析表观农艺性状改变对水稻水分和光合生理的影响和作用机制,分析表观农艺性状、水分和光合生理与耐旱性之间的联系,以期揭示水稻花期耐旱性主效基因的生理性状指标。【方法】于主茎见穗至此后的15 d进行干旱处理,研究花期干旱胁迫对水稻近等基因系剑叶和根系生理活性的影响。【结果】花期干旱胁迫下,各水稻近等基因系表现出不同的抗旱性,且耐旱性与表观农艺性状间并无明显规律可循,与正常浇水条件下水稻本身的水分和光合特性也无显著相关性,但花期干旱胁迫条件下,水稻抗旱系数与剑叶含水率和剑叶水势降幅的相关系数分别为0.614＊＊和0.514＊＊,与气孔导度降幅的相关系数为0.541＊＊,表明花期干旱胁迫下水稻的耐旱性与剑叶含水量、水势和气孔导度的降幅这3个水分生理参数密切相关。此外,除Fv/Fm的降幅与抗旱系数的相关系数为0.470＊外,花期干旱胁迫下水稻光合生理指标改变值与耐旱性无显著相关性。【结论】水稻花期干旱胁迫下的水分生理参数变化值可作为筛选耐旱水稻品种的指标。

英文摘要：

[Objective] An indica near-isogenic rice lines were treated with drought stress at flowering stage to study water and photosynthetic physiology changes of flag leaf. By analyzing the relationships among agronomic phenotype characters, water and photosynthetic physiology changes and fertility of rice, the authors try to accumulate data for drought tolerance evaluation of rice. [Method] The rice materials were suffered with drought stress begin from heading of main shoot for 15 days, water and photosynthetic physiology parameters were measured after treatment. [Result] The results showed that the indica near-isogenic rice represented various drought tolerance, and there was no correlation between drought tolerance and agronomic phenotype characters, neither with physiological activities of rice under well watered condition. However, under drought stress at flowering stage, the correlation coefficient between drought resistance indexes and changes of water content of flag leaf, water potential of flag leaf, stomatal conductance of flag leaf were 0.614＊＊, 0.514＊＊ and 0.541＊＊, respectively. This indicates that rice drought tolerance has a correlation with changes of water content, water potential and stomatal conductance. In addition, except the correlation coefficient between drought resistance indexes and changes of Fv/Fm of flag leaf （0.470＊）, there was no correlation between rice drought tolerance and photosynthetic physiology. [Conclusion] In summery, the changes of water physiology parameters could be used asindicators for screening rice with drought tolerance.