开花集中度是影响粳稻细胞质雄性不育系异交结实率的重要因素

阐明粳稻细胞质雄性不育系开花习性与异交率之间的关系，是选育高异交率粳稻不育系的重要基础。在对284份滇一型粳稻细胞质雄性不育系的自然异交率检测和部分不育系开花性状观测的基础上，通过相关分析和开花习性的精细比较，发现粳稻不育系间自然异交结实率变化幅度较大，大多数粳稻不育系的自然异交率都比较低，但同时也鉴定出少量高异交率的不育系。相关分析发现颖花的开颖角度与粳稻不育系的自然异交结实率呈显著正相关。通过对三个不育系开花性状的精细观察分析，显示了开花集中度是影响粳稻不育系异交率的重要因素。在粳稻不育系的育种实践中应该加大对不育系开颖角度和开花集中度的选择，以提高粳稻不育系的异交结实率。

Concentration of Florets Flowering Time is the Important Factors Affecting Outcrossing Rate of Japonica Rice CMS Lines

Clarifying the relationship between the flowering characters and the outcrossing rate of japonica rice CMS lines, is important foundation for high outcrossing rate of japonica rice CMS lines breeding. Based on the evaluation of the outcrossing rate of 284 Dian-type CMS lines and the flowering characters observation in parts of CMS lines, the correlation analysis and fine comparation methods are used, the results indicated that the outcrossing rate is great different among the japonica rice CMS lines, and most of the lines possess relatively low outcrossing rate, but a few of high outcrossing rate lines are also identified. The correlation analysis shows that the floret opening angle (FOA) is significant positive correlated with the outcrossing rate. After fine observation of the flowering habits in three CMS lines, the results show that the concentration of florets flowering time (CFFT) is the main factors affecting outcrossing rate of japonica rice CMS lines. In conclusion, in breeding activity, the FOA and CFFT should be focused to improve the outcrossing rate of the japonica rice CMS lines.