花后低温对水稻籽粒灌浆与内源激素含量的影响

摘要

Low temperature (LT) after flowering impacts greatly on grain filling, decreasing rice quality through extended filling duration, shortened filling rate, and decreased physiological activity.Indica-japonica hybrid rice has been applied widely in pro-duction practice, due to high yield potential. However, there has been little study on the effect of LT on endogenous hormones in indica-japonica hybrid cultivars at filling stage. In the study, four varieties, i.e. twoindica-japonica hybrid rice (Yongyou 538, YY538; Yongyou 17, YY17), oneindica rice (Zhongzheyou 1, ZZY1) and one japonica rice (Zhejing 88, ZJ88), were treated with those low temperature treatments at different grain filling phases, to compare endogenous hormone levels in treatments, aiming to reveal the influence of low temperature on grain filling and the response of endogenous hormone in grains to low temperature. The effect of LT on grain filling after different flowering stage appeared significantly at early grain filling stage, while a little dif-ference was observed at later filling stage, compared with CK. Furthermore, the influence on grain filling was found higher in Yongyou 17 and Zhongzheyou 1 than in Yongyou 538 and Zhejing 88. Compared with the contract, LT after flowering at early stage significantly decreased grain filling and prolonged grain filling duration in Yongyou 17, but not in Yongyou 538. Based on the effect of LT on grain filling process and its relation with endogenous hormones contents, it might be deduced that the normal grain filling should be ascribed to the significantly reduced GA3 content and the slightly increased IAA, ZR contents in develop- ing grains of Yongyou 538 at early and middle grain-filling stage. On the contrary, the significantly reduced IAA, ZR contents and the significantly increased GA3, ABA contents in Yongyou17 could restrain grain development. It should enhance grain filling of rice encounted LT by selected measures adjusting hormone in practice management.%以籼粳杂交稻甬优538、甬优17和籼稻中浙优1号、粳稻浙粳88为材料，设置灌浆期不同时段低温处理，分析籽粒灌浆过程中内源激素含量的动态变化及其差异。结果表明，花后不同时段低温对籽粒灌浆的影响表现为前期>中期>后期，而中、后期与对照差异不大，且低温对甬优17、中浙优1号籽粒灌浆的影响大于对甬优538和浙粳88。花后前期低温显著降低甬优17籽粒灌浆，延长灌浆时间，而甬优538与对照差异不明显。花后不同温度处理下供试品种内源激素含量变化存在一定差异，其变化与品种灌浆动态保持一致。花后前、中期低温明显降低甬优17籽粒中IAA、ZR含量，显著增加 GA3、ABA含量；而对甬优538显著下降 GA3含量和略增加 IAA、ZR含量，这可能是籽粒正常灌浆的主要原因。生产中可通过适宜的激素调控措施来提高水稻籽粒低温灌浆。