Abstract: By using a super high-yielding hybrid rice combination Liangyoupeijiu,its male parent 9311,female parent Pei’ai 64S and a three-line hybrid rice combination Shanyou 63 as experimental materials,the techniques of an artificial reaction system for photosynthetic membrane,and 32Pi isotopic labeling and so on,were used to study the photochemical activities of the flag leaf sheathes for Liangyoupeijiu.The means of PS Ⅰ reducing capacity of the flag leaf sheathes and blades for Liangyoupeijiu were 6.35 and 15.31 μmol/(mg·h)higher than those for Shanyou 63,respectively;the means of PSⅡoxygen release activities of flag leaf sheathes and blades for Liangyoupeijiu were 6.16 and 9.89 μmol/(mg·h)higher than those for shanyou 63 respectively,the calcium contents in extracts,the Mg2+-ATPase activities on the chloroplast membranes,the cyclic photophosphorylation activities of the flag leaf sheathes and blades for Liangyoupeijiu were also higher than those for Shanyou 63;the means of noncyclic photophosphorylation activities of the flag leaf sheathes and blades for Liangyoupeijiu were 0.25 and 0.31 μmol/(mg·h)higher than those for Shanyou 63,respectively;the photochemical avtivities of the flag leaf sheathes and blades for Liangyoupeijiu were significantly higher than those of its parents at most stages,showing heterosis over mid-parent or heterobeltiosis.It suggested that rice flag leaf sheath had completely the same kind of the photochemical activity characters as rice flag leaf blade with quantitative differences.High photochemical activities of the flag leaf sheath for Liangyoupeijiu may be one of the important reasons that Liangyoupeijiu performed super high-yielding property.

Key words: super hybrid rice, flag feaf, blade, sheath, photochemical activity

摘要： 以超级杂交稻两优培九及其父本9311、母本培矮64S和三系杂交稻组合汕优63为研究材料，采用光合膜人工反应体系和32Pi同位素标记等技术，初步研究了超级杂交稻两优培九剑叶叶鞘的光化学活性。结果表明，两优培九剑叶叶鞘及其叶片光系统Ⅰ还原能力的均值分别比汕优63高6.35和15.31 μmol/(mg·h)，光系统Ⅱ放氧活性的均值分别高出616和9.89 μmol/(mg·h)，且大多数时期达显著或极显著水平；两优培九剑叶叶鞘及其叶片浸出液钙含量均显著或极显著高于汕优63；两优培九剑叶叶鞘及其叶片叶绿体膜上Mg2+ATPase活性的均值均高于汕优63，大多数时期达显著或极显著水平；两优培九剑叶叶鞘及其叶片循环光合磷酸化活性的均值也均高于汕优63，近一半时期达显著或极显著水平；非循环光合磷酸化活性的均值分别比汕优63高0.25和0.31 μmol/(mg·h)，也近一半时期达显著或极显著水平；两优培九剑叶叶鞘及其叶片的光化学活性大多数时期显著或极显著高于亲本，具有平均优势或超亲优势；与叶片相比，剑叶叶鞘完全具有同剑叶一样的光化学活性，两者没有质的区别；两优培九剑叶叶鞘具有较高的光化学活性可能是它具有超高产特性的重要原因之一。

关键词: 超级杂交稻, 剑叶, 叶片, 叶鞘, 光化学活性