Preliminary Research For Composing Method Of Core Collection Of Chinese Sheep

The sheep Gennplasm Resource was a renew bio-resource, a material base for maintaining development of human beings, national ecological security, and the important material of production and consumption that sustained sheep-husbandry and improved life. Rightly understanding our local sheep resources, ascertaining breeds with special value in use and genetics, strengthening the discovery, location and use of special gene resource was the base to resolve the issue, and the precondition of the molecular assistant breeding and molecular design.In mis article, we studied the method of core collection of Chinese sheep construction and the feasibility. Cluster analysis was used to study the relationship of Chinese sheep breeds. Six groups were classified according to the origin, the morphological characters, and the geography distribution informations. Finally, with systematic approach, 4 Chinese sheep breeds were screened as secondary core collection from 33 Chinese local sheep breeds. The reliability of core collection was identified.The main results were as follows:1. The primary core collection, consisting of six sheep breeds: fat-tailed Han, Hu, Tengchong,Ujumuqin, Kazakh and Tibetan, was established by cluster method with the morphological characters and the geography distribution informations.2. 31 SSR primers were used to study the genetic diversity of 6 sheep breeds. A total of 326 alleles were detected. The number of alleles ranged from 6 to 17(mean: 11.24);the value of PIC(polymorphism information content) ranged from 0.608 to 0.913(mean: 0.8169). These results showed the high genetic diversity of the primary core collection.3. 33 Chinese local sheep breeds were clustered based on the geography distribution information, the morphological character and the molecolar marker character, and were classed according to the distance coefficient.4. Fat-tailed Han, Hu, Ujumuqin and Kazakh were seleced as the secondary core collection, and the reliability of core collection was identified.5. After primary cluster analysis with the geography information and the morphological character using the proper methods and proportion, the primary core collection was constructed, and was clustered again in combination with SSR data to construct the secondary core collection. The result showed that we can retain the genetic diversity and genetic complexity of the original groups by constructing the core collection.