Both genetic diversity and genetic distance between rice varieties are greatly important for rice breeding and are also all-important parameters for both selecting parental species in rice breading field and widely cultivating in agriculture.In this studies,eight agronomic traits of 81 excellent landrace rice resources from Chongqing city and adjacent areas of 31 counties were assessed,including true grains,rate of seeding,and grain weight.The results showed that the coefficient of variation of full seed number was the largest and ear length coefficient of variation on ear length was minimum.The correlation coefficient between 21 economic characters was significant.The Euclidean distance of the unweighted pair-group method with arithmetic means (UPGMA) and the clustering analysis were applied to analyze these characteristics,and the 81 materials could be divided into four groups of varieties at the threshold value of 74.3.Moreover,most of 81 rice varieties pertained to the fourth group,the first group was distinct on the part of genetic relationship.%水稻育成品种遗传多样性及品种间遗传距离的大小是品种能否在当地有效推广种植的关键因素,同时也是水稻杂交育种中选配亲本的基础.以重庆及周边地区31个区县收集到的81份优异地方资源为材料,分别考查实粒数、结实率、千粒重等8个主要农艺性状.结果表明:实粒数变异系数最大,穗长变异系数最小.农艺性状之间有21个相关系数达到极显著水平.采用欧氏距离中的非加权组平均法(UPGMA)对其进行聚类分析,当阈值取74.3时,可被划分为4个类群,优异资源资料主要集中在第Ⅳ类群中,笫Ⅰ类群与其它类群相比,遗传亲缘关系较远.
展开▼
