中文摘要：

在盆栽的甘蓝型油菜中双11号幼苗叶片上涂抹氧化剂甲基紫精（MV）,分析测定0～24h内叶片叶绿素含量和光合参数的变化,以分析光氧化胁迫影响油菜光合速率的关键因子。结果显示,油菜受到氧化胁迫后,叶绿素含量、净光合速率（Pn）、气孔导度（Gs）、胞间二氧化碳浓度（Ci）、蒸腾速率（Tr）、水分利用率（WUE）均下降,降低幅度随着涂抹时间的延长而增大;气孔限制值（Ls）却随着氧化胁迫时间的增加而升高。叶绿素组分和光合参数对氧化胁迫的敏感响应时间差异较大,胞间二氧化碳浓度和气孔限制值在2h即受到显著抑制,而水分利用率的响应相对滞后,为24h。回归分析表明氧化胁迫影响油菜净光合速率的最直接光合因素是气孔限制值。

英文摘要：

A pot experiment was conducted to investigate the characteristics of chlorophyll content and photosynthetic parameters of rapeseed（Brassica napus L.cv Zhongshuang 11） respond to daubed methyl viologen（MV）.Results indicated that the chlorophyll content,photosynthetic rate（Pn）,stomata conductance（Gs）,intercellular CO2 concentration（Ci）,transpiration rate（Tr）,water use efficiency（WUE） were decreased after MV painting,but stomatal limitation（Ls） increased under oxidant stress compared to water control.The decrement in chlorophyll,Pn,Gs,Ci,Tr,WUE and increment in Ls were time dependent respectively.The difference between chlorophyll component and photosynthetic parameter in response time to oxidant stress was significant,and the Ci and Ls were inhibited significantly at 2h,whilst there was a delay in WUE.The regression analysis indicated that Ls was the key and direct factor to net photosynthesis of rapeseed seedling stressed by MV.