Genetic diversity and population structure of Indian willow (Salix tetrasperma Roxb.) with dominant molecular markers along its distribution range in Himalayan region

Abstract

Indian willow (Salix tetrasperma) is an agriculturally useful tree which occurs over a wide geographic area across South Asia and bears importance. So far, this species has never been studied for molecular genetic diversity. The present study was, therefore, carried out to assess the genetic diversity and population structure analysis using RAPD and ISSR molecular markers in diverse genotypes from five populations covering North India. The mean number of effective alleles, Shannon information index and gene diversity i.e., 1.38 ± 0.013, 0.35 ± 0.010 and 0.23 ± 0.007, respectively were obtained with RAPD + ISSR markers. The analysis of molecular variance generated by RAPD + ISSR revealed a higher genetic variation (87%) within population as compared to that of among population (13%). Nei genetic distance was maximum (0.185) between Jammu and Kashmir and Punjab populations. Significant Mantel correlation (r=0.551,) was obtained between RAPD and ISSR markers. Bayesian clustering pattern obtained through STRUCTURE software showed four gene pools. Based on the genetic information obtained with regards to Indian willow by combining the RAPD and ISSR marker systems, it is proposed that an individual tree be selected within populations rather than among populations for the improvement of economic traits of Indian willow alongwith conservation of entire ecological populations.