Abstract: Multiplex environmental factors are generally expected to have significant effects on genetic diversity of plant populations. In this study, randomly amplified polymorphic DNA(RAPD) technique was used to reveal the genetic diversity in the same species of four populations collected from Niupidujuan(Rhododendron chrysanthum) at different altitudes, an endangered species, endemic to Northeast China. Initially, twenty informative and reproducible primers were chosen for final RAPD analysis. A total of 152 clear bands were obtained, including 143 polymorphic ones. With the help of POPGENE software, the poly rate was calculated to be 94.07% and the evenness of amplified bands for every primer was 6.8. Additionally, the mean observed number of alleles was 1.7265 with an effective number of 1.3608. An examination of the gene indicated a diversity of 0.2162 with an information diversity index of 0.3313. For these data, the clustering blurred analysis was performed with the aid of NTSYS-pc software to define the Nei’s gene diversity and the Shannon information diversity index of the four plant populations. The relationships between the genetic diversity indexes on the one hand and the geographic and climatic factors on the other hand were estimated by the Pearson correlation with SPSS 11.0 software. The results of the correlation analysis show that there were significant(P<0.05) or highly significant(P<0.01) correlations between each of the genetic diversity indexes and the different temperature which were mainly caused by the altitude different populations located. These data highlight the importance of native populations in shaping the spatial genetic structure in Niupidujuan.

Key words: Environmental stress, Genetic diversity, Randomly amplified polymorphic DNA(RAPD), Clustering blurred analysis