高产杂交水稻主要光合生理特征的研究

Studies on Characteristics of Main Photosynthetic Physiology in High-yield Hybrid Rice

[目的]探讨高产杂交水稻的高光效特性。[方法]以高产水稻组合K优52和对照品种汕优63为材料,围绕剑叶光合速率、光能的转化及碳同化等特性,比较2种水稻抽穗后的叶色值(SPAD)及净光合速率(Pn)的差异。[结果]K优52的光合速率在剑叶抽出之初略低于对照,展开后7～14d与对照相当,全展开14d后超过对照,尤其在21～35d显著高于对照;随着水稻灌浆、结实至成熟,2种水稻的叶片也随之衰老,净光合速率下降,但K优52下降速率缓慢,其剑叶净光合速率高值持续期能维持在25d左右,而对照维持在21d左右,与对照相比具有优势;2种水稻的叶片叶绿素含量的变化与光合速率变化类似。[结论]K优52灌浆结实期的净光合速率优势可能是其高产形成的主要原因。

[Objective] The study aimed to discuss the characteristics of high photosynthesis efficiency in high-yield hybrid rice.[Method] With the high-yield hybrid rice combination Kyou 52 and the CK variety Shanyou 63 as the tested materials,the difference on SPAD and net photosynthesis rate between 2 varieties after heading was compared on the characteristics of the photosynthesis rate,the conversion of light energy and the carbon assimilation.[Result] The photosynthesis rate of Kyou 52 was lower than that of CK at the dawn of full expansion of flag leaves,was equal to that of CK in 7-14 d after full expansion of flag leaves,was higher than that of CK at 14 d after full expansion of flag leaves,and specially,was obviously higher than that of CK in 21-35 d.Leaves were in senescence and the net photosynthesis rate was decreased with grain filling,seed setting to mature in 2 varieties,but the the net photosynthesis rate of Kyou 52 was decreased slowly and its persistent period of the net photosynthesis rate in flag leaf could keep 25 d,and that of CK kept 21 d,showing that Kyou 52 was in dominance comparing with CK.The changes of chlorophyll content in 2 varieties were similar to that of photosynthesis rate.[Conclusion] The advantage of net photosynthesis rate of Kyou 5 in grain-filling period maybe a leading cause of its high yield.