【作者】 张桂莲；

【导师】 陈立云；

【作者基本信息】 湖南农业大学 ， 作物遗传育种， 2006， 博士

【摘要】 以抽穗扬花期对温度敏感、且在耐热性方面具有显著差异的两个早稻品种耐热品种996及热敏感品种4628为材料，通过人工气候室控温（8:00-17:00,37℃，17:00-8:00，30℃），并以自然常温为对照，从水稻耐热性的生理、分子遗传等方面进行了系统研究。另外，在生化和细胞学方面进行了研究。获得结果如下： （1）高温胁迫对水稻花器官有影响，耐热性不同的品种间存在着显著差异。高温胁迫下水稻的花药开裂系数、花粉活力、花粉萌发率和柱头上花粉粒数比常温条件下的低；两种温度条件下，耐热品种996的花药开裂系数、花粉活力、花粉萌发率和柱头上花粉粒数变化幅度小于热敏感品种4628，差异达极显著水平，表明高温下耐热品种能保持较好的花粉散落特性和花粉萌发特性；进一步的分析表明，花药开裂系数与柱头上花粉粒数，花粉活力与结实率呈显著正相关（相关系数分别为：r=0.8476^*，r=0.9908^*）。 （2）水稻剑叶中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POX）和抗坏血酸过氧化物酶（AsA-POX）活性在高温胁迫初期均有明显增加，尔后快速下降。两种温度条件下，耐热品种996剑叶中SOD、CAT、POX和AsA-POX变幅大于热敏感品种4628；热敏感品种4628剑叶中硫代巴比妥酸反应产物（TBARS）含量和膜透性变幅大于耐热品种996；剑叶中超氧阴离子(O₂^?)产生速率和过氧化氢（H₂O₂）含量随着高温胁迫时间延长而增加，其增幅热敏感品种4628大于耐热品种996，且叶片内O₂^?产生速率和H₂O₂含量分别与TBARS积累呈显著正相关(耐热品种996相关系数分别为r=0.992^**和r=0.8731^*，热敏感品种4628相关系数分别为r=0.9731^**和r=0.9687^**)。 （3）高温使水稻剑叶叶绿素含量、净光合速率、气孔导度和非结构碳水化合物含量下降，胞间CO₂浓度和蒸腾速率升高。光合作用受到一定程度的影响。耐热品种996在高温下仍能维持较高的叶绿素含量、净光合速率、气孔导度和非结构碳更多还原

【Abstract】 The experiment with two early rice including thermo-resistant cultivar 996 and thermo-sensitive cultivar 4628, both were susceptible to temperature but differed extremely in heat tolerance during heading and flowering, was carried out in the controlled greenhouse and natural field conditions to systematically study using physiological and molecular methods.In addition, some biochemical and cytotlogical facets were studied. Seven day/night temperature(8:00-17:00, 37℃ , 17:00-8:00, 30 ℃ )after heading in greenhouse were established. The main results are as follows:(1) High temperature stress had obvious impact on the flower organ of rice. Significant different was found between two cultivars.The coefficient of anther dehiscence, the stained pollen rate, the pollen germination rate and the pollen grains on the stigma of rice under high temperature stress were lower than those under conventional temperature condition, The decrease scope of cultivar 996 were lower than that of thermo-sensitive cultivar 4628. The significant difference was found between two cultivars, indicating thermo-resistant cultivar was able to keep better pollen release and germination. The correlation were significant between the coefficient of anther dehiscence and the pollen grains on the stigma, and between the pollen vigor and seed set rate (r=0. 8476~* and r=0.9908~* respectively).(2) The superoxide dismutase(SOD), catalase(CAT), peroxidase(POX) and ascorbic acid-peroxidase(AsA-POX) activities in the flag leaf of rice更多还原