Abstract:

The lodging resistance and chemical component contents in culm and leaf sheaths were analyzed by using japonica rice cultivars with different lodging resistance during grain filling. The results showed that there were significant differences in total amount of potassium (K), silicon (Si) and soluble sugars in culm and leaf sheaths, especially total amount of Si.The physical strength and maximum bearing capacity of culm gradually decreased during grain filling, and reached the minimum at the maturity stage, in particular, the physical strength at the dough stage decreased rapidly. The contents and total amount of K and Si in culm and the content of Si in leaf sheaths were increased gradually and presented precipitation phenomenon whereas the content and total amount of K and the total amount of Si in leaf sheaths were decreased gradually and assumed output sign. Except for the total amount of K in culm at the full heading stage, the physical strength was highly significantly and positively correlated with total amounts of K and Si in culm during grain filling, and significantly and positively correlated with the total amount of soluble sugars in culm at the full heading stage and milky stage, with the total amounts of Si and soluble sugars in leaf sheath at the full heading stage and with the total amount of K in leaf sheath at the full heading stage and milky stage. The physical strength was highly significantly and positively correlated with maximum bearing capacity during grain filling. It is suggested that increasing the amount of soluble sugars in plants at the early filling stage, and enhancing amount of Si in plants during grain filling by topdressing Si fertilizer at the early filling stage would be beneficial to improve the lodging resistance of japonica rice.

Key words: japonica rice, grain filling, lodging resistance, chemical component content, dynamic change

摘要： 分析了不同抗倒类型的粳稻品种灌浆成熟过程中茎鞘抗倒伏性和化学成分含量的动态变化。结果表明，不同抗倒类型品种茎鞘的钾、硅和可溶性糖等总量差异很大，与钾和可溶性糖总量相比，硅总量的差异较大。随着籽粒灌浆进程，不同抗倒类型品种的茎秆物理强度和最大承载量均逐渐变小，到成熟期为最小，尤其是茎秆物理强度到蜡熟期开始迅速变小，但茎的钾、硅含量和总量及叶鞘的硅含量逐渐增加，出现沉积现象，而叶鞘的钾含量和总量及硅总量逐渐减少，呈输出迹象。除齐穗期茎的钾总量外，灌浆不同时期茎秆物理强度与茎的钾总量和硅总量均呈极显著正相关；茎秆物理强度与齐穗期和乳熟期茎的可溶性糖总量，与齐穗期叶鞘的硅总量和可溶性糖总量，与齐穗期和乳熟期的钾总量呈极显著或显著正相关，灌浆各时期穗部最大承载量与茎秆物理强度均呈极显著正相关。说明提高灌浆前期的茎鞘可溶性糖总量，以及通过追施硅肥增加植株硅总量有利于提高水稻抗倒伏能力。

关键词: 粳稻, 灌浆过程, 抗倒伏性, 化学成分含量, 动态变化