[Studies on the strain differences of Schistosoma japonicum in the mainland of China. IV. Fuzzy cluster analysis on some biological characters of different isolates of Schistosoma japonicum].

In this paper, a computerized numerical systematics was used to analyse the 5 different isolates of Schistosoma japonicum in the mainland of China by means of fuzzy clustering method with 32 quantitative data of each isolate about the morphological and biological characters. A dendrogram of the 5 isolates of S. japonicum was constructed on the basis of similarity coefficients as shown. The phylogenetic relationships revealed by the present study show that the two isolates of Anhui and Hubei get together firstly in one group, then the isolates of both Yunnan and Guangxi gather in another group, while the Sichuan isolate is closely related to the group of Anhui-Hubei isolates, not to the Yunnan ones, although both Sichuan and Yunnan isolates were in the southwest China.