不同生态区粳稻资源表型遗传多样性综合评价

为探究粳稻种质资源遗传多样性,提高粳稻育种组合选配的针对性和育种效率,通过变异系数、遗传多样性指数、聚类分析、相关分析、主成分分析、二维排序分析和逐步回归分析方法对不同生态区80份粳稻种质资源的8个表型性状的多样性水平进行了分析。结果表明：8个表型性状的变异系数为11.06%~36.97%,其中,千粒重的变异系数最小,每穗总粒数的变异系数最大;8个表型性状的遗传多样性指数为1.54~2.06,其中,单株有效穗数的遗传多样性指数最高,结实率的遗传多样性指数最低;在欧式距离9.0处,可将80份参试材料分为4类,各类表型性状差异明显;根据主成分分析和综合评价结果,80份粳稻种质资源中贵州的毕大香6号综合性状排名第1位,同时筛选到每穗实粒数、千粒重、株高、穗长和单株有效穗数性状可作为粳稻种质资源综合评价的关键指标;利用主成分二维排序分析筛选到矮秆、大穗、分蘖能力强及结实率高的4类优异种质资源,结合二维排序结果,大方晚糯是在二维排序重叠种质,可作为育种中间材料。同时基于主成分构建了粳稻种质资源的综合评价方程。

Comprehensive Evaluation of Phenotype Genetic Diversity in Japonica Rice Germplasm Resources in Different Ecological Zones

In order to explore the genetic diversity of japonica rice germplasm resources, to provide information in selection of parental lines and cross combinations, and to improve the breeding efficiency in japonica rice, a total of 80 japonica rice germplasm resources, including domestic and foreign cultivars, were employed as study materials to survey eight major phenotypic traits through variation coefficient, genetic diversity index, cluster analysis, correlation analysis, principal component analysis, a two-dimensional analysis and stepwise regression analysis. The results showed: The coefficients of variation of eight phenotypic traits were 11.06%-36.97%, among which, the variation coefficient of 1000-grain weight was the smallest and the variation coefficient of the grain number per panicle was the largest. The genetic diversity indexes of eight phenotypic traits were 1.54-2.06, among which, the genetic diversity index of panicle number per plant was the highest, and the genetic diversity index of seed setting rate was the lowest. At the euclidean distance of 9.0, 80 samples could be divided into four categories, with significant differences in phenotypic traits. According to the results of principal component analysis and comprehensive evaluation of 80 japonica rice germplasm resources, Guizhou Bidaxiang No.6 for comprehensive traits ranked the first, at the same time filter to filled grain number, 1000-grain weight, plant height, panicle length and panicle number per plant, a total of five phenotypic traits could be used as the key indicators of japonica rice germplasm resources comprehensive evaluation. Based on the analysis of principal component and scatter plot, four excellent types of germplasm resources were obtained, which behaved dwarf, long spike, strong tillering ability and high seed setting. Combined with the scatter plot results, the Dafangwannuo was an overlapping germplasm in the scatter plot, which could be used as intermediate material for breeding. Thus, this work provided an evaluation equation valuable in japonica germplasm resources.