Abstract: The genetic diversity and relationship of 35 wild Magnolia biondii accessions (came from Shannxi, Henan and Hubei provinces) were analyzed by using ISSR (Inter-simple sequence repeat) markers. Ten primers selected from 100 ISSR primers (published by Columbia university) were used for amplification. A total of 154 bands were generated, of which 143 bands were polymorphic bands. The percentage of polymorphic loci (PPB) was 93.5%. According to the result of ISSR amplification, the genetic similarity coefficient among 35 M.biondii accessions ranged from 0.55 to 0.87; Nei’s gene diversity index (H) was 0.274 7; Shannon diversity index (I) was 0.427 4. The coefficient of gene differentiation (G_st) among 3 regions was 0.129 1. All these results illustrated that there was an abundant genetic diversity in M.biondii species. A significant genetic differentiation existed both within and among different regions, moreover, the former was relatively large proportion of the total differentiation. The UPGMA dendrogram demonstrated that 35 germplasms were classified into 4 major groups based on Nei’s similarity coefficient, which showed that there were some rules in geographical distribution, however, no absolute correlation with color. The result of principal coordinates analysis basically accorded with the UPGMA dendrogram analysis. Mantel test based on genetic distance and original geographic distance revealed that the genetic relationship among the studied germplasms was not strictly correlated with the geographical provenance.

Key words: Magnolia biondii, ISSR marker, genetic diversity, germplasm resources protection