水稻开花期高温胁迫条件下生理生化特性的变化及其与品种耐热性的关系  

Relationship between Some Physiological and Biochemical Characteristics and Heat Tolerance at Flowering Stage in Rice

作　　者：李敏[1] 马均[1] 王贺正[1] 汪仁全[1] 傅泰露[1] 童平[1] 吴合洲[1] 

机构地区：[1]四川农业大学水稻研究所,四川温江611130

出　　处：《杂交水稻》2007年第6期62-66,共5页Hybrid Rice

基　　金：国家科技支撑计划重大项目"粮食丰产科技工程"(2006BAD01A05);四川省育种攻关专项(2006yzgg-28)

摘　　要：以5个杂交水稻组合为材料,研究了开花期人工高温胁迫处理对剑叶部分生理生化特性的影响。结果表明,水稻开花期高温胁迫处理降低了剑叶光合速率、叶绿素含量,增加了可溶性糖、游离脯氨酸、MDA含量及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性。相关分析表明,开花期高温胁迫处理后叶绿素含量、游离脯氨酸含量、MDA含量和SOD活性的变化幅度与品种的热敏感指数呈显著或极显著相关关系,此4项指标的变化幅度可作为水稻开花期耐热性鉴定的生理指标。耐热性强的水稻品种,在开花期高温胁迫处理后剑叶叶绿素含量下降幅度小,游离脯氨酸含量和SOD活性增加幅度大,MDA含量增加小。建立了热敏感指数与MDA含量、游离脯氨酸含量和SOD活性变化幅度的逐步回归方程,可用于对水稻开花期的耐热性进行定量分析。Rice may suffer serious heat stress during its growth period, which will affect the process of physiological metabolic activities of the plants. Using five hybrids as experimental materials, the changes in photosynthetic rate, chlorophyll content, soluble sugar content, free proline content, malondialdehyde （MDA） content and antioxidative enzyme activities were studied under high temperature conditions at flowering stage. The results indicated that high temperature stress decreased the photosynthetic rate and chlorophyll contents of flag leaves, increased contents of soluble sugar, free proline and malondialdehyde （MDA） as well as the activities of superoxide dismutase （SOD）, catalase （CAT） and peroxidase （POD） in flag leaves at flowering stage. Correlation analysis showed that heat susceptibility index （HSI） was significantly or very significantly related to the relative changed percentage of the contents of chlorophyll, free proline and MDA and SOD activity under high temperature stress conditions. Therefore, these indexes could be selected as physiological identification for heat tolerance at flowering stage in rice. Under high temperature stress at flowering stage, those cultivars with strong heat tolerance would show a smaller decrease of chlorophyll content, a smaller increase of MDA and a bigger increase of proline content and SOD activity in flag leaves. The stepwise regression equation of HSI to relative changed percentage of the contents of MDA, free proline content and SOD activity was established, which could be used to evaluate the heat tolerance of rice cultivars.

关 键 词：水稻 开花期 高温胁迫 生理生化特性 耐热性 

分 类 号：S511.034[农业科学—作物学] S428