Dioscorea alata L., Dioscorea opposita Thunb., species of monocot liana, fall in the taxon of Genus of Dioscorea in the Dioscoreacea, which comprises six genuses consisting of 650 species appromixately. However, the genus of Dioscorea have more than about 600 species worldwide, and Dioscorea alata L., Dioscorea opposita Thunb. are two most regμlar species in China. Due to the progressively development of cμltivating technology and the expansion of cμltivated area, various pathogenic diseases are spawned as ...