Abstract

Based on the previous research, according to the Hierarchy clustering, the sheep populations in East and South Asia were divided into 3 groups: Mongolia group, South-Asia group and European group. In this study, the extraction of sheep was demonstrated by two discriminants based on fuzzy discriminants analysis. The discriminants were verified with sheep populations presented 34 alleles in 10 loci. The result showed the second discriminant might be the best known discriminant, which is derived from the theroy of genetic approach degree formula: Where  is the membership function of allele No, j is the group No I,  is the allele No, j is to distinguished population X,viz., the gene frequencies of allele j in group I, in population X, respectively; K is the number of allele; ξ () is the linear genetic fuzzy degree. The extraction of an unknown population was checked using the second discriminant, the result proved that the genetic approach degree was reliable for discriminant of extraction in East and South Asia, which also might reflect the course of extraction breeding of Tong Sheep, Hu Sheep and Yunnan Sheep in China, and of course, it might be extended to other genetic markers.

Key words: Sheep, genetic approach degree, extraction, fuzzy discriminant.