花后不同时期高温处理和行距对不同品种小麦旗叶光合特性的影响

Effects of high temperature stress at different post-anthesis stages and row spacing on flag leaf photosynthetic characteristics in different cultivars

在大田条件下,研究不同行距及花后不同时期高温胁迫条件对冬小麦旗叶叶绿素含量(a+b)、光合速率(Pn)、及PSⅡ潜在活性(Fv/Fo)、PSⅡ光化学的最大效率、荧光非光化学猝灭系数(qN)以及产量的影响。结果表明,灌浆前期和中期对旗叶光合参数影响较大,后期影响减小。在相同温度条件下,大穗型品种在灌浆前期受高温胁迫影响最大,而多穗型品种则在灌浆中期。采用宽窄行种植方式可以降低高温天气对花后旗叶光合的影响。

Effects of different row spacing and high temperature stress of post-anthesis on chlorophyll contents a ＋ b）, net photosynthetic rate （, Pu）, and PS Ⅱ activity （ Fv/Fo）, the maximal quantum efficiency of PS Ⅱ photohemistry （Fv/Fm）, non-photochemical quenching co-efficient （qN） of flag leaves and yield of winter wheat were studied at different stages under field conditions. The results indicated that the effects on photosynthetic parameters of flag leaves were large in early and middle grain filling stage, but decreased later. Under the same temperature, the effects of high temperature stress on large-spike wheat cultivars were the greatest in early grain filling stage, while the effects on multi-spike cultivars were in middle. The broad line and narrow line cultivation should be adopted to reduce the effects of high temperature on flag leaf photosynthesis.