大豆/玉米间作对大豆叶片光合特性和叶绿素荧光动力学参数的影响

Effect of Intercropping with Maize on Photosynthesis and Chlorophyll Fluorescence Parameters of Soybean

通过大田试验,研究了间作种植模式导致的遮阴对大豆叶片光合特性和叶绿素荧光动力学参数的影响。结果表明:间作处理增加大豆叶绿素含量、表观量子效率和CO2补偿点,显著降低大豆叶片的羧化效率(CE)、光补偿点(LCP)和光饱和点(LSP)。间作大豆叶片净光合速率(Pn)日变化由"双峰"型变为"单峰"型,日光合总量显著低于单作。间作大豆叶片气孔导度(Gs)提高,蒸腾速率(Tr)下降,胞间CO2浓度(C i)升高。此外,间作大豆叶片Fv、Fv/Fm和Fv/F0显著降低。大豆在间作导致的遮阴条件下通过提高表观量子利用效率,减少暗呼吸消耗,以利于植株在弱光环境下光合产物的积累。

The effects of shade in intercropping planting mode on photosynthetic characteristics and chlorophyll fluorescence kinetics parameters of soybean was studied by field experiment. The results showed that chlorophyll content, apparent quan- tum yield （AQY） and CO2 compensation point of intercropping soybean were increased. Carboxylation efficiency （CE） , light compensation points （LCP） and saturation point （LSP） of intercropping soybean were significantly reduced. Moreover, the photosynthesis was decreased and the net photosynthetic rate （Pn） curve changed from ＂twin peaks＂ model into ＂a single peak＂ after the intercropping. Besides, stomatal conductance （Gs） and intercellular CO2 concentration （Ci） increased, however, Fv, Fv,/Fm , Fv/F0 and transpiration rate （Tr） were significantly decreased after the intereropping. The results in- dicated that photosynthetic products were accumulated by enhancing the apparent quantum efficiency, reducing dark respiration of intercropping soybean in the shade conditions.