干旱胁迫对小麦生理特性及产量的影响

Effects of Drought Stress on Physiological Characteristics and Yield of Wheat

试验主要进行了干旱胁迫对小麦光合生理、叶绿素荧光参数和生物量及产量影响的研究。结果表明,干旱胁迫使小麦在灌浆期的净光合速率、气孔导度、蒸腾速率分别减少44.81%,71.35%,60.04%,水分利用效率增加了50.66%;在开花期,干旱胁迫使叶绿素荧光参数Fv/Fm,ΦPSⅡ,q P均显著降低,NPQ显著增加;在灌浆期,干旱胁迫对小麦叶绿素荧光参数Fv/Fm,Fv'/Fm',ΦPSⅡ,q P,NPQ均无显著影响;干旱胁迫使小麦株高、穗数等下降,地上部分生物量和产量分别下降48.75%和57.83%。干旱胁迫下,小麦叶片气孔导度下降,使CO2供应受到影响,降低了叶片净光合速率,使小麦光合代谢物下降;干旱胁迫使叶片PSⅡ反应中心遭到破坏,导致光合潜力下降,造成小麦长势变弱,地上部分生物量、产量也随之下降。

In this study, the effects of drought stress on photosynthetic physiology, chlorophyll fluorescence parameters, biomass and yield of wheat were studied. The results showed that the net photosynthetic rate reduced 44.81% in wheat under drought stress,stomatal conductance reduced 71.35% in filling stage. Transpiration rate reduced 60.04% and water use efficiency increased 50.66%. In the flowering stage, drought stress significantly decreased the chlorophyll fluorescence parameters Fv/Fm, ΦPSII, q P, and significantly increased NPQ. In the filling stage, drought stress had no significant effect on the chlorophyll fluorescence parameters Fv/Fm, Fv＇/Fm＇,ΦPS Ⅱ, q P and NPQ. Drought stress decreased plant height, spike number of wheat and so on. Above ground biomass and yield decreased 48.75% and 57.83%, respectively. Under drought stress, wheat leaf stomatal conduction decreased and CO2 supply was affected, leading to reduce leaf net photosynthetic rate and the decrease photosynthetic metabolites of wheat. Drought stress destroyed the PSII reaction center in leaves, resulting in the decrease of photosynthetic potential. The growth became weak in wheat, thus decreasing biomass and yield.