不同生育期水分胁迫对杂交水稻光合及产量性状的影响

Effect of water stress on photosynthesis and yield character of hybrid rice at different stages

对两个籼型杂交水稻B优827和冈优725分别在分蘖期、孕穗期、开花期进行不同水分胁迫处理,研究光合速率、活性氧(ROS)、超氧化物歧化酶(SOD)活性及其同功酶等生理特性和产量变化。结果显示,轻度水分胁迫下,随着胁迫时间的增加,叶片中光合速率下降、活性氧含量上升,SOD活性也相应增加;重度水分胁迫下,随着胁迫时间的增加,光合速率下降迅速,活性氧含量和SOD活性比轻度胁迫上升幅度大,但胁迫第7～9 d SOD酶活性出现降低。不同程度水分胁迫处理收获后其产量大小分别为对照>轻度>重度。对开花期的SOD进行凝胶电泳显示6条同功酶谱带,并随着胁迫程度的增加其亮度明显升高,而且品种间有明显差异。三个时期抗旱能力比较表明,其大小为孕穗期>开花期>分蘖期。B优827在三个时期的轻度、重度水分胁迫下都表现为抗旱能力比冈优725强。

Responses to three extents of water stress were comparatively studied in two indica hybrid rice differing in sensitivity at tillering, booting and flowering stages, to investigate the effects of water stress on Pn, ROS, SOD activity, SOD isozymes and yield. The result showed that, in light water stress and followed by continuing water stress, Pn decreased, ROS accumulated and the activity of SOD increased in leaves. However, in severe water stress and followed by continuing water stress, Pn decreaded rapidly, the content ROS and the activity of SOD were higher than in light water stress, but at the 7 -9 days the activity of SOD began to decrease＇ After harvest, the magnitude of yield treated with different water stress is summarized as： CK 〉 light 〉 severe. The SOD isozymes at flowering stage were analyzed by PAGE, and the results showed 6 different protein hands. Followed by increasing water stress degree, the light of protein band increased gradually. It also showed difference in two varieties. The ability of resistance to water stress at three stages were summarized as： Booting stage 〉 flowering stage 〉 tillering stage. B - You 827 had higher resistance to both light and severe water stress compared to Gangyou 725 at three stages.