Study on Relationship Between Drought Resistance and Flag Leaf Photosynthetic Characteristics of Wheat Varieties

Six wheat varieties with different drought resistance were planted in normal irrigation or drought conditions.The drought resistant abilities of tested wheat varieties were compared,and the relations between the drought resistance and the photosynthetic characteristics of flag leaf at flowering stage were studied.The results showed that the tested wheat varieties had similar photosynthetic rate(Pn) at flowering stage at normal irrigation condition.Under drought condition,the Pn and the stomatal conductance(g s) were significant different among the tested varieties at flowering stage:Jinmai 33,Henong 859 had higher Pn and g s at flowering stage,this was useful to their drought resistance.The Pn and g s of Jimai 3235 and Zhongmai No.9 were greatly influenced at flowering stage,this may be one reason for their bad drought resistance.Changle No.5,Wenmai No.6 had higher Pn and g s at flowering stage,yet their drought resistance was poor.It indicated that the bad drought resistance of Changle No.5 and Wenmai No.6 were controlled by other physiological metabolism after flowering stage.