重穗型水稻植株抗倒伏能力的研究

以18个不同穗重型水稻品种为材料，研究了重穗型水稻植株的抗倒伏能力及其与茎秆的物理性状、机械组织特性的关系。结果表明：重穗型品种单穗重大、产量高与其株高的适当增加密切相关。重穗型品种由于单穗重和株高的增加，弯曲力矩加大，但抗折力也明显提高，故而其茎秆抗倒伏能力并未降低。重穗型品种茎秆抗折力强的主要原因

The Culm Lodging Resistance of Heavy Panicle Type of Rice

The lodging resistance of the culm and its characteristics of physics and mechanics related to the trait in heavy panicle type of rice (HPT) were studied. The weight per panicle and the grain yield were significantly positively correlated with the plant height. The heavier panicle and the higher yield of HPT were significantly correlated with its longer culm. The bending moment of the basal internodes in HPT increased due to its heavier panicle and higher plant, but the breaking resistance was also obviously increased and it resulted in that the lodging index had no change comparing with medium panicle type of rice. The reasons for the breaking resistance increase were: (1)The increase of the culm length originated from the first and the second internode other than from the basal internodes (the fourth, the fifth and the sixth internode). (2)HPT had a larger area in the basal internode cross section, thicker culm wall and higher amount of dry weight of stem and leaf sheath in the basal internode. (3)HPT had thicker mechanics tissue in its culm wall, thicker cell wall, more cell layers, higher xylemized and cellulousized status of epidermis cell, more and larger vascular bundles. It was also found that the thick and sturdy basal internode could increase not only the breaking resistance, but also the panicle weight and grain yield. Some suggestions for the HPT rice breeding and its culturing practices were also discussed.