辽宁水稻籽粒在穗轴上分布特点及其与结实性的关系

Distribution of Rice Grain on Panicle Axis and Its Relationship with Seed Setting in Liaoning

以辽宁近年来育成的水稻品种(系)为试材进行研究,结果表明,供试品种可以分为高、中、低产3种类型,穗数是高产品种<中产品种<低产品种,每穗粒数和结实率相反,千粒重无显著变化;高产品种生物产量高于中、低产品种,高、中产品种经济系数高于低产品种;产量与穗数呈极显著负相关,与每穗粒数、结实率、一次枝梗粒数、二次枝梗粒数、着粒密度及经济系数呈显著或极显著正相关;产量与每穗粒数关系最密切,而每穗粒数主要由二次枝梗粒数决定,其次是着粒密度和一次枝梗粒数。二次枝梗结实率与整穗结实率呈极显著正相关,与产量亦呈极显著正相关;高、中、低产品种一次枝梗数峰值分别在12～14、10～13和8～12;低产品种二次枝梗粒数较少,中、高产品种二次枝梗粒数均较多,前者主要分布于穗轴中、下部,后者主要分布于中、上部。

Rice varieties developed in recent years in Liaoning were used as materials, including high yielding varieties(HYV), medium yielding varieties(MYV) and low yielding varieties(LYV). The results showed that the panicles were in theorder of HYV<MYV<LYV, the spikelets per panicle and seed setting rates were just opposite, and 1000-grain weight had nosignificant difference. The biomass of HYV was higher than that of MYV and LYV, and the harvest indexes of HYV and MYVwere higher than that of LYV. There was a significant negative correlation between grain yield and panicles. The paniclescorrelated positively with the spikelets per panicle, primary branch grains, secondary branch grains, seed density andharvest index. The grain number per panicle was mainly determined by secondary branch grains. Seed setting rate ofsecondary branches correlated positively with seed setting rate of whole panicle and grain yield. The highest value for HYV,MYV and LYV was 12-14,10-13,8-12, respectively. LYV had fewer secondary branches grains, and HYV and MYV hadmore secondary branches grains; the former mainly distributed in middle and lower parts on panicle axis, while the lattersmainly distributed in middle and upper parts on panicle axis.