Study on Genetic Variation in Yak Breeds by RAPD Technique

124 yaks of Maiwa,Jiulong,Datong and Tianzhu white yak breed were selected and the genetic diversity of them were determined by using RAPD and AFLP molecular marker technique in this paper.The result showed that : ①there were 18~33 DNA fragments were amplified for each RAPD primer and there were polymorphic for all of breeds.The mean value of marking polymorphism frequency was 38.63%.The length of fragment amplified was ranged from 0.25 kb to 5 kb.②The genetic diversity index of different yak breeds were calculated with the use of Shannon diversity index equation and its result was 0.311 in Jiulong yak,0.262 in Maiwa yak,0.252 in Datong yak,0.216 in Tianzhu white yak.③The genetic distance DR of 4 yak breeds were derived from Rogers' genetic distance equation,there was the largest genetic distance between Tianzhu white yak and Jiulong yak,the smallest value was existed in between Tianzhu white yak and Datong yak.The 4 yak breeds were clustered into 2 kinds,Jiulong yak belongs to one and the three others belongs to another.