Then the genetic distance and shannon information index among these 13 strains were obtained by using the software popgen2 on the basis of pcr - rflp patterns . the phylogenetic tree was constructed by using the upgma algorithm method ( mega2 software package ) . the shannon information index indicated that there was a higher genetic diversity among the frankia strains and some strains had a big genetic distance with others 根据酶切图谱，通过popgen2软件计算各供试菌株之间的遗传距离；用shannon信息指数计算种群遗传多样性；利用upgma法( mega2软件)对所获得的遗传距离矩阵进行聚类分析，得到13株供试frankia菌株间系统发育的聚类分析树状图谱。
