Implication of ITS phylogeny for biogeographic analysis, and comparative study of morphological and molecular interspecies diversity in Indian Impatiens

Abstract

Genus Impatiens is widely distributed in the areas of Old World tropics and subtropics. Of which, only European and United States Impatiens were examined for genetic diversity analysis. In this study, 10 Indian Impatiens were studied for their interspecies genetic diversity based on inter-simple sequence repeat (ISSR) markers and morphological characters. All 73 DNA fragments amplified using 6 ISSR markers were polymorphic. Diversity indices for ISSR markers were ranged from He = 0.2183 to 0.3733, I = 0.3533 to 0.5579, genetic similarity coefficient = 0.5135 to 0.8409 and average PIC value as 0.7523 for each marker. These results indicate the presence of high amount of genetic diversity among studied Impatiens species. Computed p-value (0.941) obtained for Mantel test reveals nonsignificant correlation of the diversity and relationship among Impatiens shown by ISSR markers and morphological characters. Studied Impatiens were divided in to 4 groups based on clustering results in unweighted pair group method with arithmetic mean (UPGMA) dendrogram of ISSR and morphological data. Resolution of these species obtained using ISSR data limitedly supports the sectional classification. Biogeographic history of Impatiens based on ITS phylogeny using Bayesian Binary Markov Chain Monte Carlo method (BBM) confirmed the South-East Asian origin of Impatiens. This study gave an idea about interspecies diversity in Indian Impatiens and suggests the suitability of ISSR markers for further interspecies diversity studies in Impatiens.