Molecular Phylogeny of Balsams (Genus Impatiens) Based on ITS Regions of Nuclear Ribosomal DNA Implies Two Colonization Events in South India

Abstract

The present investigation is the first attempt of its kind to analyze the phylogenetic association of Impatiens species of South India by placing them in the global Internal Transcribed Spacer (ITS) phylogeny of Impatiens. Representative samples from all the seven sections of genus Impatiens reported from South India were collected. Total genomic DNA was extracted from fresh plant leaf and Polymerise Chain Reaction (PCR) was carried out using ITS specific forward and reverse primers. Forty seven sequences from representatives of seven sections of Impatiens species from South India and 45 Impatiens sequences from other centers of Impatiens diversity were obtained from GenBank and used to reconstruct the evolutionary relationships within the genus Impatiens. Maximum Parsimony (MP) analysis was conducted by using PAUP*v.4.0b10. Bayesian Inference (BI) analysis was carried out in MrBayes v.3.2.2. Molecular phylogeny of South Indian Impatiens spp. based on ITS sequences showed the same association as that of morphological taxonomy. This study including all representative extant sections of South India, indicates that South India was colonized from Southeast Asia by two independent dispersal events i.e., once by ancestral species of sections Scapigerae, Epiphyticae, Tomentosae, Sub-Umbellatae and Racemosae and another time by ancestral species of sections Microsepalae and Annuae.