Study On Genetic Diversity And Inbreeding Degree Of Domestic Yak And Tibetan Sheep In Qinghai Province Based On SSR Markers

Domestic Yak(Poephagus grunniens)and Tibetan sheep(Ovis aries)are indigenous species living in the Qinghai-Tibet Plateau,they adapted to the high-cold,low-oxygen and high-radiation geographical environment in the Qinghai-Tibet Plateau with long-term evolutionary process,and developed into the advantages species in Qinghai province,and played an important role in economic development and rational utilization of grassland.In the breeding process of domestic Yak and Tibetan sheep in Qinghai,herdsmen often adopted the animal husbandry method of self-reproducing and intensive breeding,and introduced foreign varieties without plan,which affected the sustainable development of domestic Yak and Tibetan sheep populations.To assess the genetic diversity and inbreeding degree of domestic Yak and Tibetan sheep in Qinghai,promote the sustainable development of ecological animal husbandry in Qinghai,this paper chosen 27 Yak microsatellite and 23 Tibetan sheep microsatellite loci,by microsatellite fluorescence labeling method to scientifically analysis genetic diversity and inbreeding degree of domestic Yak and Tibetan sheep all four geographic populations in Qinghai.The main research results were as follows:(1)all 27 microsatellites of Yak had moderated to high polymorphism;only 2 of 23 Tibetan sheep's microsatellites had low polymorphism,and the remaining 21 loci were in moderate to high polymorphism.(2)the genetic diversity of four geographic groups of domestic Yak was higher as that of Tibetan sheep.(3)the genetic differentiation of domestic Yak was low,inbreeding was found within and between subgroups;while the genetic differentiation was not obvious in Tibetan sheep,inbreeding was also found within and between subgroups.(4)the genetic variation of domestic Yak populations was mainly caused by intra-population variation,and the UPGMA cluster of each group showed that the clustering relationship was not consistent with the geographical distribution,the optimal clustering number of populations genetic structure K=3;the optimal clustering number of population genetic structure K=5 in Tibetan sheep,and it's genetic variation of populations was mainly caused by intra-population variation,it's UPGMA clustering agreed with the geographical distribution characteristics.