温度与小麦穗花发育及结实的关系

在1987—88年及1989—90年,采用分期播种形成不同温度条件,研究了不同品种穗花发育的变化及其与结实率的关系。以非线性回归方程确定幼穗分化各期的起点温度与有效积温,以积分回归度量温度与小花数的关系,以幂函数方程探讨四分体及开花前后温度对穗粒数的影响。结果表明,小麦幼穗分化及持续时期均表现积温效应,但品种类型间不同时期的起点温度与有效积温不同;幼穗分化期间,温度的时间分布对总小花数有着显著影响,而孕穗前5天及孕穗—开花期的温度与结实率呈正相关。本文还讨论了四川小麦幼穗分化过程中引致穗粒数变异的时期,以及安全孕穗、抽穗期。

THE RELATIONSHIP BETWEEN TEMPERATURE AND EAR AND FLOWER DEVELOPMENT AND SEED SETTING OF WHEAT

The relationship between temperature and ear and flower development and seed setting of different cultivars in wheat was studied under different temperature conditions which were fermed by different sowing dates. Fundamental temperature and effective accumulation temperature were determined by using nonlinear regression equation, Y=(a+bx)/x. The relationship between temperature and flower number were quantified by integral regression. Quantitative effect of temperature from tetrad to the time before flowering was probed into by using power function, Y=aX~b. The results showed as follows. The speed and duration of ear differentiation was influenced by accumulation temperature. But the fundamental temperature and effective accumulation temperature of different stages differed with different cultivars. The total flower number was influenced significantly by the time distribution of temperature during ear differentiation. There was a postive relation between seed setting percentage and temperature of five days before booting as well as the temperature of stage from booting to flowering. The stage controlling seed number per ear during ear differentiation, safe booting date and safe heading date of wheat in Sichuan were discussed.