| This study analyzed the genetic diversity, and explored the genetic relationship between different geographical origin, and constructed core collection of 286 rice germplasm materials introduced from abroad or nonlocal, using phenotypic traits and SSR. The results obtained are as follows:1. Analysis of phenotypic traits indicated that ten quality traits are more performance similarly and seventeen quantitative traits had been reached extremely significant level. Analyses of genetic diversity of phenotypic traits showed that the genetic genetic diversity index of quantitative traits was 2.13, and quality traits was only 0.23.2. According to UPGMA clustering method of phenotypic traits, Euclidean distance was 0.84 as the threshold value, the tested materials were clustered into four categories, the group Ⅰ containing eight materials with multy number grains, the group Ⅱ containing sixty-six materials with high yield and highly seed setting rate, the group Ⅲ containing three materials with dwarf characters, the group Ⅳ containing 209 materials, accounting to 73.08% of the total varieties had intermediate type characters. The cluster analysis were analyzed among different geographical origin of germplasms, the group Ⅰ contain materials which was from Portugal, the group Ⅱ contain materials which was from Heilongjiang Province and Jilin Province, the materials which was from Australia was clustered into group Ⅳ, others are clustered into category Ⅲ.3. Analyze the all materials by SSR, the result indicated that the average number of alleles per locus is 3.5357, the variation range of the effective number of alleles was 1.0428-4.7667 and the average genetic diversity index was 0.6145. RM1306, RM3513 and RM3509 had higher number of alleles and higher genetic diversity. Chr9 is the most high of genetic diversity index in 12 chromosomes.4. SSR showed that Shannon diversity index (Ⅰ) ranged between 0.0619-0.6161 of rice germplasm resources from different geographic origins, in which Italy had the highest diversity index was 0.6161 and Taiwan had the lowest was 0.0619. Diversity index in Beijing and Yunnan were also respectively higher, reaching 0.6002 and 0.5977. In addition, the number of alleles, polymorphic sites in Italy, Beijing and Yunnan were relatively higher. So the germplasms which was from different geographical origin had difference of diversity. SSR genetic distance and cluster analysis showed that the germplasms had close genetic relationship and small genetic distance between the three northeastern provinces and Japan with 0.0300 about, the genetic distance between Portugal and Taiwan is the farthest with 0.4571.Portugal had far genetic distance with any place.5. Using SSR and phenotypic traits analysis, It has built a core collection which contains 28 materials, accounted for 10% of total resources. The phenotypic variance of core collection was. 82.35%.The core collection was in line with a standard which the mean percentage difference of less than 20%, and poor compliance rate greater than 80%. The genetic distance of core collection was average 0.4611 and the variation range was 0.1814-0.8065. The materials of core collection were from complex pedigree and with diverse traits. The core collection of germplasms retained only 10% of the original samples, but the polymorphic loci, percentage of polymorphic loci, the observed number of alleles, effective number of alleles and retention Shannon information index of core collection was 94.64%,94.64%,88.99%,101.11%,106.02%,so the core collection can represent the original germplasm well and provides a theoretical basis for breeding. |
PDF Full Text Request