中文摘要：

为研究油菜角果皮光合衰退的机理及其对产量的影响，本文以中双9号、中油杂11号和华油杂14号油菜品种为材料，测定花后角果光合及其生理特征，探讨角果光合衰退与生理指标间的相关关系及其对油菜产量的影响。研究结果表明，油菜角果皮光合速率随叶片衰老而逐渐降低，1,5-二磷酸羧化酶（RuBPcase）、可溶性蛋白和叶绿素含量，以及超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性均呈现出下降趋势，膜脂过氧化作用产物丙二醛（MDA）的含量在叶片光合功能衰退过程中逐渐上升。不同品种间角果衰老过程中光合高值持续期不同。相关性分析结果表明，叶绿素含量、可溶性蛋白含量、SOD、CAT以及MDA含量等与角果光合速率呈现显著或极显著二次抛物线型相关关系，而与RuBPCase活性呈极显著线性正相关关系（P〈0.01）。

英文摘要：

Photosynthetic rate, chlorophyll content and enzyme activity of silique wall of rapeseed were investigated to study the mechanism on declining of rapeseed silique photosynthesis and its effect on yield. Materials included 3 cultivars as Zhongshuang 9 （ZS9）, Zhongyouza 11 （ZYZ11）and Huayouza 14 （HYZ14）. Results showed that net photosynthetic rate （Pn） decreased during silique growth. Similar responses were found in ribulose 1,5 - bisphosphate carboxylase （RuBPcase） content, soluble protein content, chlorophyll content, superoxide dismutase （SOD） and catalase （CAT） activities in silique wall. The progressive increase of malondialdehyde （MDA） occurred during the silique stage. Results showed that silique photosynthetic rate had significant correlations in second-degree parabola with contents of chlorophyll, soluble protein, MDA, and activities of SOD and CAT. Furthermore, RuBPCase had highly significant linear relationships with contents of chlorophyll, soluble protein, MDA, and activities of SOD.