不同抗旱类型小麦品种开花期光合特性的研究

Studies on Photosynthetic Characteristics at Flowering Stage of Winter Wheat Varieties With Different Drought-resistant Ability

在田间不同水分条件种植下,比较了不同抗旱类型小麦品种开花期旗叶的气孔结构、气孔导度、光合速率,分析了该时期小麦品种的抗旱机制。结果表明:供试品种在正常水分处理条件下,开花期气孔导度(gs)、光合速率(Pn)幅度在123.3～170.7mmol·m^(-2)·s^(-1)、20.85～24.16μmol·m^(-2)·s^(-1)、;而在旱处理条件下,开花期gs、Pn差别很大,幅度在58.5～98.2mmol·m^(-2)·s^(-1)、7～23μmol·m^(-2)·s^(-1)。抗旱性较强的品种晋麦33、河农859在开花期保持较高的gs、较强的Pn,有利于其适应旱胁迫;冀麦3235、中麦9号开花期gs、Pn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gs、较强的Pn,但其抗旱系数(DRC)、抗旱指数(DRI)都很低,说明开花期的Pn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。不同的小麦种质资源在不同的生育阶段有不同的抗旱机制。

6 wheat varieties with different drought resistance were planted in different irrigation conditions. The stomatal conductance( gs ) , the photosynthetic rate(Pn)of flag leaves at flowering stage and their drought resistance were compared. The results showed that the tested wheat varieties had similar gs, Pn at flowering stage at normal irrigation condition. Under drought condition, the gs,Pn were significantly different among the tested varieties at flowering stage: Jinmai33, Henong859 had higher gs, Pn at flowering stage, this was useful to their drought resistance. The gs, Pn of Jimai3235 and Zhongmai9 were greatly influenced at flowering stage, this may be one of the reasons for their poor drought resistance. Changle5, Wenmai6 had higher gs,Pn at flowering stage, yet their drought resistance was poor. It indicated that the poor drought resistance of Changle5, Wenmai6 were controlled by other physiological metabolism. The drought resistance mechanisms were different among different wheat varieties.