不同小麦品种抗旱机制与花期旗叶光合特性的关系

在田间水、旱处理条件下 ,比较了不同抗旱类型小麦品种的抗旱性 ,分析了供试品种抗旱性与开花期旗叶的光合特性的关系。结果表明 ,供试品种在正常水分处理条件下 ,开花期光合速率 (Pn)无明显差别 ;而在旱处理条件下 ,开花期光合速率、气孔导度 (gs)差别很大 ,幅度分别在 7～ 2 3μmol·m- 2 ·s- 1、 5 9 5～ 98 2mmol·m- 2 ·s- 1,抗旱性较强的品种晋麦 33、河农 85 9在开花期保持较强的光合速率、气孔导度 ,有利于其适应旱胁迫 ;冀麦 32 35、中麦 9号开花期光合速率、气孔导度受到很大抑制 ,可能是其抗旱性较差的因素之一 ;昌乐 5号、温麦 6号虽然在开花期保持较高的光合速率、气孔导度 ,但其抗旱系数 (DRC)、抗旱指数 (DRI)都很低 ,说明开花期的光合特性对其影响并不大 ,其抗旱性差是开花期以后生理代谢过程受到影响的结果

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.