不同生育阶段夜温升高对双季水稻产量的影响

利用两间玻璃温室内夜间不同的温度条件,研究了水稻不同生育阶段的夜温升高对双季早、晚稻产量的影响.结果表明:播种-幼穗分化(一次枝梗分化期)期间夜温升高,有利于双季水稻的分蘖,植株有效穗数显著增加,平均夜间最低温度每升高1℃,双季早、晚稻的产量分别提高10.02%～13.18%和6.52%～7.78%(P0.01);幼穗分化-抽穗(10%稻穗抽出剑叶鞘)期间夜温升高,导致颖花退化,使每穗发育颖花数减少,平均夜间最低温度每升高1℃,双季早、晚稻的产量分别下降3.76%～6.67%和3.66%～6.94%(P0.01);灌浆结实期(抽穗-成熟)夜温升高,双季早稻的结实率和产量显著下降,而双季晚稻的结实率和产量显著提高,平均夜间最低温度每升高1℃,双季早稻的产量下降2.07%～5.61%(P0.05),双季晚稻的产量提高1.63%～2.28%(P0.05).表明不同生育阶段的夜温升高对双季水稻产量的影响存在明显差异.

Effects of nighttime temperature increase at different growth stages on double season rice grain yield

Two experimental glass houses were utilized to study the effects of nighttime temperature increase (NTI) at different growth stages on the grain yield
 of double season rice. The NTI from the stage of sowing to panicle differentiation (primary branch differentiation) improved the tillering of rice, and increased the effective panicles. An average 1 ℃ rise in the minimum nighttime temperature (MNT) at this stage increased the grain yield of early and late rice by 10.02%-13.18% and 6.52%-7.78% (P＜0.01), respectively. The NTI from the stage of panicle differentiation to heading (10% panicle heading from flag leaf sheath) promoted the spikelet abortion, and reduced the number of developed spikelet. An average 1 ℃ rise in MNT at this stage decreased the grain yield of early and late rice by 3.76%-6.67% and 3.66%-6.94% (P＜0.01), respectively. NTI from the stage of heading to maturity decreased the filled grain rate of early rice remarkably, but had an opposite effect on late rice. An average 1 ℃ rise in MNT at this stage induced a grain yield loss  by 2.07%-5.61% (P<0.05) and a grain yield gain by 1.63%-2.28% (P＜0.05) for early and late rice, respectively. All the results illustrated that there existed obvious differences in the effects of NTI at different growth stages on the grain yield of double season rice.