中文摘要：

【目的】探讨在高温和干旱胁迫下不同水稻品种产量和品质形成的特点。【方法】常规中熟籼稻品种黄华占（耐热品种）和双桂1号（热敏感品种）与超级稻品种两优培九（两系杂交籼稻）和扬粳4038（粳稻）种植于盆钵，于抽穗和灌浆早期（始穗后0-10d）设置高温（日最高温度为37．5℃）、干旱（土壤水势保持在-30±10kPa）、高温＋干旱3种处理，以同期自然温度且正常供水为对照。【结果】与对照相比，高温、干旱和高温＋干旱3种处理均显著降低了各品种的花粉可育率、受精率、结实率和产量；降低了精米率、整精米率和崩解值，增加了垩白米率、垩白度和消减值。高温及高温＋干旱处理对产量和稻米品质的影响，热敏感品种双桂1号大于耐热品种黄华占，两优培九和扬粳4038大于双桂1号和黄华占。干旱对产量和稻米品质的影响，热敏感品种大于耐热品种；双桂1号和黄华占大于两优培九和扬粳4038。高温、干旱或高温＋干旱胁迫对产量和稻米品质的影响与其对根系氧化力、叶片光合速率和抗氧化保护酶活性的影响结果趋势一致。【结论】抽穗与灌浆早期高温或干旱胁迫对水稻产量和品质的影响在品种间存在很大差异，双桂1号和黄华占的耐热性强于两优培九和扬粳4038，两优培九和扬粳4038的耐旱性则强于双桂1号和黄华占。在高温或干旱胁迫下根系氧化力、叶片光合速率和抗氧化保护酶活性高是一些水稻品种保持较高产量的重要生理原因。

英文摘要：

[Objective] Heading/flowering and early grain filling are the most stress-sensitive periods in rice growth and development. However, little is known about how high temperature and water stress during these periods affect rice yield and grain quality. This study investigated pollen development, yield components, grain quality and some physiological parameters under high temperature and water stress during heading and early grain filling periods. [Method] Two conventional indica rice cultivars, Shuanggui 1 （heat-sensitive） and Huanghuazhan （heat-tolerant）, and two super rice cultivars, Liangyoupeijiu （indica-inclined two-line hybrid） and Yangjing 4038 （japonica）, were grown in pots and subjected to high temperature treatments （HT, maximum temperature during the day at 37.5℃）, soil drying treatments （SD, soil water potential at -30±10 kPa） and high temperature plus soil drying treatments （HT＋SD）, and the natural temperature plus well-watered treatment was taken as the control （CK）. [Result] The results showed that high temperature, soil drying or high temperature plus soil drying treatments significantly reduced pollen fertility rate, fertilization rate, seed-setting rate, grain yield, milled rice, head rice and break down viscosity, increased chalky grains, chalkiness degree and setback viscosity in each cultivars. The effect was more obvious on heat-sensitive than on heat-tolerant cultivars, and more evident on Liangyoupeijiu and Yangjing 4038 than on Shuanggui 1 and Huanghuazhan under both high temperature and high temperature plus soil drying treatments. The result was discrepant under soil drying treatments, the extent of the decrease or increase was more on heat-sensitive than on heat-tolerant cultivars, but more evident on Shuanggui 1 and Huanghuazhan than on Liangyoupeijiu and Yangjing 4038. The effect of high temperature treatments, soil drying treatments or high temperature plus soil drying treatments on yield and grain quality was consistent with that on root activity,