气温对杂交水稻Ⅱ优718结实率的影响分析

本文采用5个品种,6个播期的裂区试验设计,研究在自然高温和低温胁迫下Ⅱ优718的结实率表现。结果表明:①结实率的大小依次是:辐恢838>Ⅱ优838>辐恢718>Ⅱ优718>Ⅱ-32B;②结实率与产量的回归系数大小依次是:Ⅱ优718>辐恢838>Ⅱ优838>辐恢718>Ⅱ-32B;③抽穗前15 d的活动积温和有效积温对结实率的影响较小,而抽穗后的活动积温和有效积温对结实率的影响较大;④Ⅱ优718、Ⅱ优838在抽穗后都具有一定的耐高温性,且Ⅱ优718、Ⅱ优838的耐高温性主要来自于其父本;⑤辐恢718的耐高温性能比辐恢838好,Ⅱ优718、Ⅱ优838比3个亲本的耐高温性能都好;⑥各品种的耐低温性依次是:Ⅱ优838>辐恢838>Ⅱ优718>辐恢718>Ⅱ32B,且Ⅱ优718与Ⅱ优838两个品种的耐低温能力在同一水平上;⑦Ⅱ优718与Ⅱ优838的结实率受父本的影响均大于母本。

Effect of air temperature on the seed-setting rate of hybrid rice variety II You 718

The seed-setting rate in hybrid rice II You 718 was compared with another four varieties in a split block experiment design under natural high temperature and low temperature stress environments in six sowing dates.The following experimental results showned:(i)Seed setting rate for the five varieties rank from high to low as follows:Fu You 838,II You 838,II You 718,II-32B,respectively;(ii)Regression coefficients between seed-setting rate and yield rank from high to low as follows:II You 718,Fu Hui 838,II You 838,Fuhui 718,II.32B;(iii)The actively accumulated temperature and effectively accumulated temperature 15 days before heading have small influence on the seed-setting rate while the actively accumulated temperature and effectively accumulated temperature after the heading have greater influence on the seed.setting rate;(iv)Both II You 718 and II You 838 have high temperature resistance;the high temperature resistance in II You 718 and II You 838 mainly inherits in their male parents;(v)Fuhui 718 has higher resistance than Fu Hui 838 to high temperature,and II You 718 and II You 838 have higher resistance than the three parents to high temperature;(vi)The resistance to low temperature ranks as follows:II You 838,Fuhui 838,II You 718,Fu Hui 718,II-32B;and II You 718 and II You 838 have similar low temperature resistance;(vii)The male parents have greater influence on II You 718 and II You 838 than their female parents do.