宁夏水稻选育品种遗传多样性和亲缘关系分析

Genetic Diversity and Genetic Relationship of Inbred Japonica Rice Varieties in Ningxia

选择31份宁夏近年来育成或审定的水稻品种（系）,利用分布于12条染色体的36对SSR引物进行遗传多样性和遗传距离分析.共检测到159个等位基因,品种间不同位点等位基因数目不等,平均4.4个.Nei基因多样性指数变幅为0.031 7~0.844 4,平均为0.508 8.按育成或审定年份,把31份水稻分为3组,SSR分析结果表明,随着年份的增加,等位基因数和遗传多样性指数均有增大趋势,且3群体间等位基因数差异达极显著水平（P=0.006 3）.UPGMA聚类分析表明,参试水稻品种在遗传相似系数为0.50水平上聚为5类,其中第Ⅰ、Ⅱ、Ⅳ类均为1个品种（系）,绝大多数品种被聚为第Ⅲ、Ⅴ两类.第Ⅲ类包括7个品种,21份品种（系）被归为第Ⅴ类,占参试材料数的67.7%,大多数宁夏自育的品种（系）被聚为此类.与宁夏水稻选育品种系谱比较,SSR标记真实地反映了宁夏水稻的亲缘关系.虽然近年来宁夏水稻的遗传多样性有增加的趋势,但遗传基础狭窄,其绝大多数品种的相似系数在0.5以上,最高达0.94.在今后的新品种选育中除了考虑亲本的亲缘关系外,应继续加大力度引进和创新亲本材料,拓宽宁夏水稻的遗传基础.

A total of 36 SSR markers distributed in 12 chromosomes were used to analyze genetic diversity and genetic relationship in 31 inbred rice varieties of Ningxia.159 alleles were revealed.The mean number of alleles per locus was 4.4.Total genetic diversity index of Nei varied greatly among loci from 0.031 7 to 0.844 4,with an average 0.508 8.The 31 rice varieties were divided into 3 groups for released by years.As the time goes on,the number of alleles and genetic diversity showed an increasing trend,and the number of allele increased significantly（P=0.006 3）.UPGMA cluster analysis showed that five categories were clustered in the level of genetic similarity coefficient of 0.50.The Ⅰ,Ⅱ and Ⅳ categories are a variety or line,respectively.Most varieties were clustered into the Ⅲ and Ⅴ categories.The Ⅲ included seven species.21 varieties or lines were clustered in the Ⅴ,which percent was 67.7% in the tested varieties.The major rice inbred varieties or lines were clustered into this category.Compared the pedigree of rice varieties,SSR markers reflected the real rice genetic diversity and genetic relationship in Ningxia.Although the genetic diversity of rice is an increasing trend in recent years,the genetic base of rice varieties is still narrow in Ningxia.The similarity coefficient of majority varieties is 0.5 or more,up to 0.94.Breeders must introduce and innovate in more rice parental materials in addition to considering the genetic relationship between the parents in the future.