Effect of Water Supply on Photosynthetic Characteristics of Mung Bean Seedling

[Objective] The purpose was to research the effect of different water supply on photosynthetic physiological characteristics of mung bean seedling so as to confirm reasonable scope of water supply.[Method] Four kinds of water supply were designed by simulating the rainfall of Changchun,which were Treatment Ⅰ:150 mm,Treatment Ⅱ:250 mm,Treatment Ⅲ:350 mm and Treatment Ⅳ:450 mm resp.The effect of different water supply on the photosynthetic physiological characteristics of mung bean seedling was analyzed with multiple indexes.[Result] The daily mean values of mung bean leaves of different water supply were as follows: Treatment Ⅲ Treatment Ⅳ Treatment Ⅱ Treatment Ⅰ,their daily mean values of stomatal conductance were as follows: Treatment Ⅳ Treatment Ⅲ Treatment Ⅱ Treatment Ⅰ and their daily mean values of water utilization rates were as follows: Treatment Ⅲ Treatment Ⅱ Treatment Ⅰ Treatment Ⅳ.The daily variation trends of transpiration rate and stomatal conductance of mung bean of different water supply were basically uniform.The variations of intercellular CO2 concn.of Treatment Ⅰ and Treatment Ⅱ were basically uniform and that of Treatment Ⅲ and Treatment Ⅳ in afternoon were basically uniform.The daily variation of stomatal limit of Treatment Ⅰ and Treatment Ⅱ showed as obvious bimodal curve and that of Treatment Ⅲ and Treatment Ⅳ showed non-obvious bimodal curve.[Conclusion] The suitable water supply of mung bean seedling was 250-350 mm.