剑叶抽出后高温对杂交稻产量及其性状的影响

Effects of High Temperature after Emergence of Flag Leaf on Yield and Its Traits of Hybrid Rice

[目的]探究剑叶抽出后杂交水稻对高温的响应及耐热性。[方法]采用玻璃温室增温法,以感热指数为指标,研究了剑叶抽出后高温对8个杂交稻新组合产量及其性状的影响并评价耐热性。[结果]剑叶抽出后高温导致所有杂交稻品种实粒数、结实率、千粒重和单株产量明显减少,空粒数明显增加,而有效穗、成穗率、穗长、穗茎粗、一次枝梗、二次枝梗、总枝梗数、总粒数和着粒密度的增减因组合而异。千粒重的感热指数与抗热系数呈显著相关,可作为剑叶抽出后水稻抗热性评价的可靠指标在生产实践中应用。性状感热指数的聚类分析显示,茶优99082、03A/999046、振优99082和跃丰6A/R225具有强抗热性,II优551、天丰优551和II优225具有中抗热性,II优50329具有感热性。[结论]该研究可为参试各品种的推广应用提供理论依据。

[ Objective ] The aim was to explore the response to high temperature of hybrid rice after the flag leaf taking out and its resistance to heat. [ Method] Eight novel combinations of hybrid rice were used to evaluate the effects of high temperature after emergence of flag leaf on yield and its traits of hybrid rice and heat resistance with the heat susceptibility index in glasshouse warming method. Results showed that high temperature after emergence of flag leaf resulted in significant decrease of filled grains, seed-setting rate, thousand-grain weight and yield per plant, significant increase of non-filled grains ; while the changes of effective panicles, productive tiller percentage, panicle length, panicle neck thickness, primary branches, secondary branches, total branches, total grains and grain density differed with combinations. Heat suscep-tibility index of thousand-grain weight and heat resistance coefficient were significantly correlated, which thousand-grain weight could be used as dependable index for evaluating hybrid rice heat resistance to be put into production practice. Cluster analyses with heat indexes of yield traits suggested that Chayou99032 and 03A/999046, Zhenyou 99082 and Yuefeng 6A/R225 had strong heat resistance; Ⅱ you551, Tianfengy-ou 551 and Ⅱ you 225 had medium heat resistance; and Ⅱ you 50329 was heat susceptibility. [ Conclusion ] The study provides a theoretical basis for popularization of each combination in this test.