The uniformity of yield components and the photosynthesis characteristics during the later growth stages of rice varieties with different harvest indexes; namely Yuexiangzhan, Changsizhang, Wuxing-simiaol , Yuexiuzhan were comanatively analyed, and the results were as follows; There were differences in the indexes of agronomic characteristics in the varieties with different harvest indexes, in different plants, especially in the different stem-panicles of the same plant, namely the uniformity was different. The harvest index uniformity of the high harvest index varieties among the plants, and stem-panicles in the plant were higher than those of low harvest index varieties. The CV ( coefficient of variation) and the changing ranges of the effective panicles per plant, total grains per plant, and total filled grains per plant, seed-setting rate, filled grain weight per plant, stem weight per plant, and 1 000-grain weight of the high harvest index varieties were lower than those of low harvest index varieties as a whole. The CV and the changing ranges of the plant height, panicle length, total grains per panicle, and total filled grains per panicle, seed - setting rate, filled grain weight per panicle, stem weight per panicle, and 1 000-grain weight of the high harvest index varieties were lower than those of low harvest index varieties as a whole too. The difference in the photosynthesis rate of flag leaf 20, 30 days after heading of different varieties was insignificant. The SPAD of flag leaf from 0 day to 30 days after heading of high harvest index varieties was higher than that of low harvest index varieties, and it decreased more slowly. The temperature of flag leaf 20 days after heading of high harvest index varieties was lower than that of low harvest index varieties, but that of 30 days after heading was reverse. Temperature gap of flag leaf and atmosphere 20 days after heading of high harvest index varieties was lower than those of low harvest index varieties, but that of 30 days after heading was in reverse. The correlations between the CV of plant height, panicle length, total grains per panicle, total filled grains per panicle, 1 000-grain weight, filled grain weight per panicle, weight per stem, grain density, total grains per plant, effective panicles per plant and harvest index were all negative, in which, the correlations between the CV of weight per stem and harvest index were significantly negative ( -0. 942 7 * ). It suggested that higher uniformity of the agronomic characteristics would increase the harvest indexes of rice varieties.%对比分析了不同收获指数型水稻品种粤香占、长丝占、粤秀占和五星丝苗1号产量构成因子的整齐度及生育后期光合特性的差异性,结果表明:不同收获指数型品种农艺性状各指标既存在品种间差异性,也有株间的差异性,更有单茎穗间的差异性,即其整齐度不同；高收获指数型品种单株之间与单株内单茎穗间收获指数整齐度均高于低收获指数型品种；高收获指数型品种单株之间有效穗数、总粒数、实粒数、结实率、实粒质量、秆质量、千粒质量的变异系数及极差总体上低于低收获指数型品种,其单株内不同茎蘖间株高、穗长、总粒数、实粒数、结实率、实粒质量、秆质量、千粒质量的变异系数及极差总体上也低于低收获指数型品种；不同收获指数型品种之间抽穗后20 d、30 d光合速率差异不显著；高收获指数型品种抽穗当天至30 d剑叶SPAD值均高于低收获指数品种,且下降更为缓慢；高收获指数型品种抽穗后20d剑叶温度均低于低收获指数品种,抽穗后30d则高于低收获指数品种；高收获指数型品种抽穗后20 d气叶温差低于低收获指数品种,抽穗后30 d则高于低收获指数品种；株高、穗长、单穗总粒数、单穗实粒数、千粒质量、单穗实粒质量、单茎秆质量、着粒密度、单株总粒数、单株有效穗数等农艺指标的变异系数与收获指数间均呈现负相关,其中单茎秆重的穗间变异系数与收获指数间呈现极显著负相关(-0.942 7+),表明上述农艺指标整齐度高有利于提高水稻品种的收获指数.
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