干旱对小麦灌浆期旗叶光合等生理特性的影响

对盆栽小麦开花灌浆期进行正常供水(CK)、中度干旱胁迫(MS)和严重干旱胁迫(SS)3种水分处理,测定旗叶各生理指标变化。结果表明:花后0～28d,中度干旱胁迫的旗叶中可溶性蛋白含量变化与对照接近,严重干旱胁迫下可溶性蛋白含量较低;开花8天以后,两种干旱处理旗叶中可溶性糖含量均高于对照,在开花第28天,分别高出对照2.8％和3.7％;两种干旱处理,开花16d以前,旗叶中脯氨酸(Pro)含量急增,尔后又降低;整个开花灌浆期间,中度干旱胁迫旗叶中叶绿素含量、光合速率、蒸腾速率、气孔导度和单叶WUE与对照接近,严重干旱胁迫处理下,则明显较低,但单叶WUE增加;随着干旱程度增加旗叶水势降低;花后23d时,严重干旱处理水势低于对照1.3MPa。

Effect of drought stress on photosynthesis and some other physiological characteristics in flag leaf during grain filling of wheat

There are three water treatments in this study, that is control (CK), moderate drought stress (MS), severe drought stress (SS), during anthesis and filling stage of wheat. Some physiological characteristics of flag leaf was measured. The results showed that the contents of soluble protein in flag leaf under moderate drought stress was similar to that under control during 0-28 days post-anthesis, and lower under severe drought stress. After 8 days of anthesis, the contents of soluble sugar in flag leaf of two drought treatments is higher than that of control, and respectively higher 2. 8% and 3. 7% on 28 days of anthesis. The contents of proline was significantly increased in flag leaf under two drought treatments before 16 days of anthesis, and then decreased, The contents of chlorophyll, rate of photosynthesis and transpiration, stomatal conductance, Single leaf WUE in flag leaf under moderate drought stress is similar to that under control during grain filling stage, but obviously reduced under severe drought stress except for leaf WUE. With drought increasing the water potential in flag leaf declined, and in severe drought stress was 1. 3MPa lower than that of control on 23 days of anthesis.