在田间试验条件下研究了花后不同时期高温、弱光和温光双重胁迫对小麦籽粒内源激素含量与增重进程的影响。结果表明，灌浆中期温光双重胁迫处理对小麦粒重的影响最为显著，不同时期3种处理后，单粒重的降低主要是缓增期灌浆速率和平均灌浆速率显著降低所致，而灌浆持续期对其影响较小。灌浆进程中籽粒GA3含量的降低或ABA含量的升高可能是导致平均与最大灌浆速率以及渐增期、快增期和缓增期灌浆速率变化的生理原因。对籽粒各内源激素变化速率之间及其与籽粒平均灌浆速率的相关分析表明，对籽粒灌浆速率的调节作用GA3主要体现在灌浆前期（开花后7~12 d）和后期（开花后19~28 d）；而ABA主要是在灌浆中期（开花后12~19 d），且籽粒平均灌浆速率与ABA之间的关系要比其与GA3的关系相对密切。整个籽粒灌浆过程，ZR和IAA含量变化与籽粒平均灌浆速率的相关性均不显著。
The overcast, rainy, weak light or preternatural high temperature weather, which badly affects the grain weight, frequently occurs after anthesis. Previous studies have indicated that the effects of ecological factor on wheat grain weight were realized by changing the endogenous hormone contents. While little information is available on grain filling process and endogenous hormone contents under high temperature and light stress after anthesis of wheat. Therefore, effects of high temperature, shading stress and double stress of them after anthesis on grain filling process and endogenous hormone contents of wheat were investigated. Compared with CK, all stress treatments obviously reduced kernel weight and the effect of double stress of high temperature and shading at metaphase on kernel weight was the most significant. The decline of single kernel weight was mainly caused by the decrease of slight-increase period filling rate and mean filling rate, and not by filling duration, which had a little effect on kernel weight. The changes of mean filling rate, maximum filling rate, slow-increase period filling rate, fast-increase period filling rate and slight-increase period filling rate were attributed to a decrease of GA3 or increase of ABA in the grains during grain filling. The correlations among changing rates of endogenous hormones indole-3-acetic acid (IAA), gibberellin (GA3), zeatin riboside (ZR), and abscisic acid (ABA) as well as mean filling rate in grain were analyzed. The results showed that the grain filling rate was mainly regulated at the early grain filling stages (7 to 12 days after anthesis) and late grain filling stages(19 to 28 days after anthesis) by GA3 and at middle grain filling stages(12 to 19 days after anthesis) by ABA. The correlation of the mean filling rate with ABA was closer than that with GA3. No significant correlation was found between grain filling rate and the changes of ZR or IAA content during the whole grain filling period.
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