Genetic analysis of colchiploidy populations of guava using microsatellite markers

Abstract

Introduction - An attempt was made to evaluate the genetic variation across 102 progenies of guava developed by colchicine treatment by using sixteen microsatellite markers. Materials and methods - A total 102 putative ploidy progenies were obtained by treating seeds and seedlings of guava cv. 'Arka Kiran' and 'Arka Mridula'. SSR genotyping was carried out by using 16 SSR lo i and ϐluorophores were used to label the primers at their 5' end. CERVUS 3.0.3 software and GenAIEx 6.5 were used to analyse the genetic diversity at both locus and population levels, respectively. To characterize the population structure accession was grouped by genetic similarity using the STRUCTURE 2.3.4 program. Results - The results of the diversity analysis identiϐied 151 alleles with 6-16 alleles having an average polymorphic value of 0.732 (mean of 9.44 alleles/loci). The value of observed and expected heterozygosity, Shannon's information index and coefϐi ient of inbreeding for 16 SSRs were 0.407, 0.63ͻ, 1.171 and 0.401, respectively. Among all treatments, the seed treated progenies of 'Arka Kiran' recorded the highest number of alleles (5.563), effective alleles (3.228), Shannon's information index (1.283), observed and expected heterozygosity (0.411 and 0.635) and ϐixation index (0.3ͺ2). Clustering and population structure of progenies distinctly separated 'Arka Kiran' and 'Arka Mridula' into two major groups. Principle coordinate analysis (PCoA) showed 37.7ͻ% of variation ontributed by the ϐirst three o-ordinates. Analysis of molecular variance (AMOVA) showed 16%, 75% and 9% variation among the population, among individuals, and within the individuals, respectively.