Abstract:

The purpose of this article was to supply theory foundation for study on protection, utilization and evaluation of germplasm resource by researching genetic variation of local sheep. Genetic diversity of 4 local sheep breeds were analyzed by 5 microsatellite marks. Statistical analysis of population genetics was executed according to the composition and frequency of alleles. UPGMA dendrograms were constructed respectively based on the standard genetic distance and Nei’s genetic distance. 70 alleles were detected in 4 local sheep breeds, the number of alleles among all loci was from 10 to 18, the average effective number of alleles (Ne) was ranged from 3.81 to 5.68, the average of polymorphism information content (PIC) was ranged from 0.6152 to 0.7373, the average heterozygosity was ranged from 0.6711 to 0.7820, and the genetic differentiation coefficient was 0.0847 in 4 local sheep breeds. The standard genetic distance and Nei’s genetic distance between Jinzhong sheep and Ujmuqin sheep were the biggest (0.5775, 0.6126), and between Small-tail han sheep and Ujmuqin sheep were the smallest (0.1542, 0.1955). Small-tail han sheep and Ujmuqin sheep got together first as one type, Jinzhong sheep and Guangling big-tail sheep got together secondly as another type, two types got together last. The results showed that genetic diversity and genetic variance were enriching in 4 local sheep breeds, genetic differentiation among breeds was small, but differentiation had obvious between Small-tail han sheep, Ujmuqin sheep and Jinzhong sheep, Guangling big-tail sheep. The 5 microsatellite loci were all highly polymorphic loci, which could be regarded as the analysis of effective genetic marks on genetic diversity and phylogenesis in sheep. Molecular phylogeny among all local sheep was coincided with the forming history, the differentiation and the geopolitical location.

Key words: sheep; microsatellite; genetic diversity; phylogenetic relationship