Genetic variability inCitrussp., related genera and hybrids from germplasm collection by random amplified polymorphic DNA (RAPD)

Abstract

The tools of molecular biology have enabled the improvement of citrus with significant reduction in identification and selection of new materials, and are usually preferred for genetic diversity assessment, population genetic structure and mapping. Relationships among 24 accessions of Citrus species, related genera and hybrids were investigated using random amplified polymorphic DNA (RAPD). A dendrogram based on the unweighted pair-group method for the arithmetic mean method was constructed using a similarity matrix derived from 96 polymorphic RAPD fragments. High polymorphism was detected among the accessions and the number of fragments/primer/accession ranged from 2 to 8. Accession-specific DNA fragments were observed for Murraya and Feroniella oblata. Within the subtribe Citrinae, the genera Poncirus, Microcitrus, Severinia and Atalantia were more distant from Citrus, and Fortunella was the most closely related. The Citrus species clustered in one group, including possible hybrid species, and the data did not support a separation into the subgenera Citrus and Papeda. Although RAPD technique sometimes has been criticized, it still can be used with successfully and this study confirmed these markers are useful and efficient for analysis of variability in citrus species. The information generated will be important for breeding programs using citrus germplasm.