Analysis of molecular diversity in guava using RAPD markers

Abstract

SummaryRandomly amplified polymorphic DNA markers were used to estimate molecular diversity of 41 genotypes of guava consisting of five Psidium species, 23 varieties, 12 selections and a hybrid. PCR amplifiable DNA was isolated using the CTAB method, and 93 amplified fragments were obtained from eight random 10-mer primers. The genetic dissimilarity matrix calculated based on Squared Euclidean Distance revealed maximum genetic distance of 54% between the variety Mirjapur Seedling (P. guajava) and P. quadrangularis, while the minimum distance was only 11% between SWY-1 and GR-1 Navalur selections. Based on Ward's method of cluster analysis, all the individuals on the dendogram were grouped into two major clusters according to their geographical locations and species. The species were interspersed between the varieties. The present studies showed that the genetic base of Indian guava can be rated as low to moderate diversity and also indicated that various triploid seedless cultivars of guava are not genetically identical and have independent origins. All the species used in the study could be subspecies of P. guajava.