牦牛品种的AFLP分析及其遗传多样性研究

Study on Genetic Diversrty in Yak Breeds by AFLP

采用AFLP分子标记技术对麦洼牦牛、九龙牦牛、大通牦牛和天祝白牦牛进行了遗传多样性分析,结果表明：7个AFLP引物组合共获得156个片段,其中98个为多态性标记,标记多态频率为34.8%～54.65%,平均每对引物可获得17.57条带。九龙牦牛、麦洼牦牛、大通牦牛、天祝白牦牛的Shannon遗传多样性指数分别为0.268、0.251、0.160、0.130,九龙牦牛最大,麦洼牦牛次之,天祝白牦牛最小。用Rogers遗传距离公式分析得到4个牦牛品种间的遗传距离DR,天祝白牦牛与九龙牦牛遗传距离最大（0.028 2）,天祝白牦牛与大通牦牛的距离最小（0.025 3）。根据DR值,将4个牦牛品种聚为两大类,九龙牦牛聚为一类,其它3个牦牛品种聚为一类。

The genetic diversity of Maiwa yak, Jiulong yak, Datong yak, Tianzhu white yak was studied by using AFLP molecular marker technique. The result indicated ： 7 primer combinations showed polymorphism and acquired 156 fragments with 98 polymorphism marks. Marking polymorphism frequency was 34.89% -54.65%, and 17.57 belts was obtained on average from each primer： according to the AFLP analysis results, the genetic diversity indexes of yak species by using Shannon diversity index equation were obtained： the genetic diversity index among Jiulong yak community was 0. 268, and Maiwa yak 0. 251, Datong yak 0. 160, Tianzhu white yak 0. 130. The genetic diversity of Jiulong yak is the largest, and the second the is Maiwa yak, Tianzhu white yak had the minimum. The genetic distance DR of 4 yak species was derived from Rogers＇ genetic distance equation, the largest genetic distance exists in Tianzhu white yak and Jiulong yak（0. 028 2）, and the smallest value was between Tianzhu white yak and Datong yak（0. 025 3）; The 4 yak breeds was clustered into 2 kinds, Jiulong yak belongs to one and the three others to another group.