Studies on Genetic Diversity and Polymorphism of Acacia constricta and Acacia farnesiana

In this study, the genetic diversity and polymorphism of the A. farnesiana and Acacia constricta species were examined using randomly amplified polymorphic DNA (RAPD). Several groups have reported on the utility of RAPD markers as a source of phylogenetic information. The seeds of 10 varieties of A. constricta and A. farnesiana were randomly selected from five districts (Namakkal, Perambalur, Nagapattinam, Ramanathapuram and Pudukkottai) of Tamil Nadu, India. Analyses using RAPD data revealed 87.5% polymorphism. The genetic closeness between varieties of both species ranged from 29 to 93%. Between the species, the GT-8 variety of A. constricta and GCT-2 of A. farnesiana had the lowest genetic similarity (29%), but the GT-8 and GT-6 varieties of A. constricta had the most genetic similarity (41%), with the variety GCT-3 of A. farnesiana. Polymorphism was found in 51% of the fragments amplified with 22 SSR primers. The genetic similarity between cultivars of both species ranged from 20 to 91%. The first cluster was exhibited by three A. constricta types, whereas the second cluster was revealed by seven A. farnesiana species with two sub clusters, and GCT-3 was linked separately to the main cluster. The examination of genetic similarities and clustering patterns between RAPD and SSRs revealed almost 85% similarity. SSR analysis has, the varieties Cocker-1, GCT-2 and GC-1 are grouped together with close genetic similarity when compared to the grouping pattern of varieties in RAPD analysis. In variants cultivated in Tami Nadu, isoenzyme analysis of the peroxidase and polyphenol oxidase enzymes revealed species-specific bands as well as bands specific to the Acacia genus. In analyzing the diversity of Acacia species, these important data may aid researchers in identifying duplicate accessions.