水稻灌浆结实期阴害的初步研究

本文阐明了江苏早稻灌浆结实期阴害大约10年5遇;中、晚稻阴害约10年4～5遇。水稻遭受阴害后,植株体内糖氮比例失调,叶片叶绿素(a+b)含量下降,光合作用受阻,导致结实率和千粒重下降。然而,不同品种的耐阴特性各异,阴害使籼稻类型品种植株的可溶糖和淀粉含量下降多;含氮量的增加,籼(杂交)粳稻无明显差异,剑叶叶绿素含量、结实率和千粒重的减少率,品种间差异颇大。随着施氮量和肥料的组合不同,水稻耐阴特性亦有明显差异。

A PRELIMINARY STUDY OF INSUFFICIENT ILLUMINATION DURING THE GRAIN-FILLING AND FRUIT STAGE OF RICE

The insufficient illumination effect during the grain—filling stage has been studied. For early rice, the insufficient illumination effect oceured about 5 times per ten years in Jiangsu Province, and for middle and late rice, about 4 to 5 times per ten years. When rice crops were suffering from the insufficient illumination effect, the ratio of earbohydrates to nitrogen in riee plants failed inbalance. The chlorophyll (a+b) content in rice leaves decreased, and the photosynthetic rate declined. As a result, both the fertility and grain weight of paddy dropped. However, the tolerance of insufficient illumination in different varieties, were different, Under insufficient illumination effect, the content of soluble sugar and starch in Indiea rice decreased more rapidly than that in Japonica rice. The increase of nitrogen content in the two varietal types difference was not significant. The reduction of chlorophyll content in flag leaves, the decrease of fruit and grain weight were considerably different among varieties. The insufficient illumination tolerance of rice plants was also effected obviously, by the nitrogen application rate and combination of fertilizers.