Abstract: Seven characteristics, i.e. plant height, panicle length, length of panicle neck, days till heading, total grains per panicle, filled grain rate, special filled grain rate, were genetically analysed under low temperature treatment by using Kunmingxiaobaigu, a Yunnan rice landrace, and Towada, a japonica variety cultivated widely in Japan, and their F₁, F₂ and B₂F₁ populations. The results showed that filled grain rate, and special filled grain rate (filled grain rate of nine spikelets from the 3rd to 5th spikelet of three primary rachis branches at the top of each panicle) were the two most sensitive characteristics, could be used as indicators of cold tolerance evaluation at booting stage. Rates of variance of plant height and panicle length at low temperature treatment also could be used as indicators of cold tolerance evaluation. Genetic analysis results showed that there is one or two loci of major gene manipulating the grain fertility. The rates of characteristic approaching to that of recurrent parent by backcrossing are dependent on characteristic itself.

Key words: booting stage, characteristics, cold tolerance, genetic analysis, rice

摘要： 以云南稻种资源昆明小白谷与日本品种十和田配制的杂交F₂、B₂F₁等为材料,在低温处理条件下研究了昆明小白谷7个农艺性状的遗传特性。结果表明总结实率和特定结实率是对低温最敏感的性状，可用作孕穗期耐冷性的评价指标，在无法用结实率来评价耐冷性时，也可用株高、穗长的变异率作为耐冷性指标。遗传研究发现有1～2对主基因参与调控结实率性状,回交使性状向轮回亲本趋近的速率因性状而异。

关键词: 性状, 耐冷性, 遗传分析, 孕穗期