Abstract: Spikelet density is an important trait related with panicle number,spikelet number and grain weight.Its genetical behaviour expressed as follows:At F₁ generation,the spikelet density was higher than the average density of the parents;F₂ generation gave a population distribution of spikelet density as normal curve. In our'opinion,this phenomenon belonged to quantitative inheritance and was controlled by multiple genes.Through this experiment,we have identified that spikelet density is correlated with plant height,flag-leaf length,flag-leaf width,panicle length,grain number per panicle,sterility and yielding capacity of the individual plant.We think that this should be noticed by rice breeders.

Key words: Indica rice, Spikelet density, Quantitative character inheritance, Genetic analysis

摘要： 水稻小穗着粒密度是一个重要的农艺性状,其与单株穗数、小穗数和粒重等有密切的联系。该性状在密穗品种与疏穗品种杂交的 F_1值高于双亲平均值,F_2群体分布呈近正态分布的曲线。因此该性状属多基因制约的数量性状,而且和单株生产力有显著相关,故必将受到水稻育种家的重视。

关键词: 籼稻, 着粒密度, 数量性状遗传, 遗传分析