摘要
在温室无土栽培条件下研究了镁对黄瓜开花结果期光合特性的影响。结果表明,多镁胁迫增加了黄瓜叶片叶绿素a、叶绿素b含量,降低了胡萝卜素含量,缺镁胁迫使黄瓜叶片叶绿素a、叶绿素b、胡萝卜素含量均极显著降低,但缺镁胁迫的叶绿素a/b最高;缺镁胁迫下黄瓜叶片净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)的日变化呈单峰曲线变化,而多镁胁迫下Pn和Tr呈双峰曲线;多镁和缺镁胁迫的胞间CO2浓度(Ci)、多镁胁迫的Gs呈近似倒抛物线型;多镁和适镁处理叶片的光饱和点、CO2饱和点以及表观量子效率和羧化效率都大于缺镁处理。缺镁胁迫下黄瓜光合作用主要是受非气孔限制,而多镁胁迫下气孔因素和非气孔因素二者兼具。
The effects of magnesium stress on photosynthetic character of cucumber were studied in greenhouse and under soitless condition. The results showed that the contents of chlorophyll a, chloro-phyll b were inecreased, and carotenoids content decreased under Mg-excessive, the contents of chloro-phyll a, chlorophyll b and carotenoids were extremly significantly decreased under Mg-deficiency. Net photosynthesis rate （Pn） , stomata conductance （Gs） and transpiration rate （Tr） changed in one-peak curve under Mg-deficiency, Pn and Tr changed in double peak curve under Mg-excessive. Ci under Mg-excessive and Mg-deficiency, Gs under Mg-excessive changed in inverted parabolic curve in daytime. Light saturation point, CO2 saturation point, apparent quantum yield and carboxylation efficiency under Mg-excessive and Mg-optimum are higher than Mg-deficiency. The main limiting factor of photosynthesis of cucumber seedling is non-stomata factors under Mg-deficiency. They were both stomata and non-stomata factors under Mg-excessive.
出处
《中国蔬菜》
北大核心
2009年第6期36-40,共5页
China Vegetables
基金
国家"863"计划项目(2001AA24701)
重庆市自然科学基金项目(CSTC2007BB1354)
关键词
黄瓜
镁胁迫
光合特性
Cucumber
Magnesium stress
Photosynthetic character
