结实期土壤水分与氮素营养对水稻产量与米质的影响

EFFECTS OF SOIL MOISTURE AND NITROGEN NUTRITION DURING GRAIN FILLING ON THE GRAIN YIELD AND QUALITY OF RICE

以汕优63和武育粳3号为材料,研究结实期水分胁迫和氮素营养对水稻产量和米质的影响。结果表明:水分胁迫处理的叶片水势在白天明显低于对照(非胁迫处理),但早晨和傍晚的叶片水势在2种处理间无明显差异,说明胁迫处理植株的叶片水势在晚间得到恢复。水分胁迫处理叶片的叶绿素含量和光合速率明显降低,植株衰老加快,而抽穗期施用氮肥处理植株衰老延缓。水分胁迫处理促进了茎鞘储存的非结构性碳水化合物(可溶性糖和淀粉)的输出。产量以及大多数米质指标在土壤水分胁迫与非胁迫处理间无明显差异,抽穗期施用氮肥可显著提高产量。

With Shanyou 63 and Wuyujing 3 as materials, the effects of water stress and nitrogen nutrition during grain filling on the grain yield and quality were studied. The result showed that the leaf water potential of water-stressed rice plants was significantly lower than that of non-stressed plants during the day. But there were no significant differences in leaf water potentials between the stressed and non-stressed plants at the predawn and in the evening, suggesting that the stressed plants can rehydrate overnight. Water stress decreased chlorophyll content and photosynthetic rate of leaves, indicating that it enhances senescence. Application of nitrogen at heading slowed down senescence. Water stress facilitated remobilization of nonstructural carbohydrate (soluble sugars + starch) from the stem and sheath. The differences in the grain yield and most indices of grain quality were insignificant between the stressed and non-stressed treatments. Topdressing nitrogen at heading significantly increased grain yield.