RESUMEN
This article assessed the genetic relationship and genetic diversity in Dioscorea alata. Twenty samples were examined to identify their original plants, and analyzed by ISSR markers. The results showed that 20 samples were classified into three different plants, such as D. alata, D. persimilis, and D. fordii. There was significant difference in genetic similarity coefficient between D. alata and D. persimi as well as D. fordii. There was distinct differences in D. alata, the genetic similarity coefficient was resulted from 0.672 9 to 0.990 7. With UPGMA clustering method, 16 samples of D. alata could be divided into 4 groups. After comparing samples with the phenotypic characteristics of original plants, it showed that the color and the number of tuber were the most important characteristics of judging the genetic relationship of D. alata. It is concluded that the genetic variation of Dioscorea spp is significant, especially the genetic diversity in D. alata were in a high level. This article supplied a molecular biologic support for distinguishing Dioscorea spp, and also provided basis for breeding of D. alata.