Indian Journal of Biotechnology Vol 9, April 2010, pp 137-146 RAPD analysis in mungbean [Vigna radiata (L.) Wilczek]: I. Assessment of genetic diversity Madhu Saini, Subhadra Singh*, Z Hussain 1 and A Yadav Department of Genetics, CCS Haryana Agricultural University, Hisar 125 004, India 1 National Bureau of Plant Genetic Resources, Pusa Campus, New Delhi 110 012, India Received 24 March 2009; revised 22 July 2009; accepted 25 September 2009 Genetic diversity was estimated among 39 genotypes of mungbean [Vigna radiata (L.) Wilczek] using 30 RAPD primers. A total of 411 RAPD amplicons were obtained, of which 382 (92.9%) were polymorphic. The per cent polymorphism ranged from 42.85 to 100 per cent. A wide range (40.8 to 90.3%) of Jaccards similarity coefficient was observed between the pairs of genotypes; the highest being observed between MH-98-1 and Vs ML-839, and the lowest between UPM-98 and Vs ML-131. The genotypes with a common ancestry and/or used repeatedly in mungbean improvement programme exhibited higher genotypic similarity. The extent of diversity among cultivars was also studied in relation to their source, and set of genotypes with narrow genetic base developed from particular place were identified. The genotypes formed 11 clusters, three main groups and eight minor groups, based on unweighted pair group methods for arithmetic mean (UPGMA). The cultivar ML-131 occupied a unique position and was most diverse from rest of the genotypes. Principal coordinate analysis and normalized Mantel statistics (r=0.92) supported cluster analysis. A concordance was observed between the position of genotypes in the cluster and their pedigree information. Keywords: Cluster analysis, genetic diversity, green-gram, molecular analysis, principal coordinate analysis, RAPD Introduction Mungbean [Vigna radiata (L.) Wilczek], also known as green-gram, belonging to subgenus Ceratotropis is an important legume crop. It is rich in protein (25.9%) and lysine content (504 mg/g), and has an important place in vegetarian diet. The yield of mungbean has not been increased substantially due to insufficient use of genetic diversity in breeding programmes 1 . A better knowledge of genetic diversity of breeding material is prerequisite for an efficient crop improvement programme. Assessment of genetic diversity has traditionally been made through morphological characters that are often limited in number, have complex inheritance and vulnerable to environmental conditions 1 . It is well documented that the DNA markers have many advantages over the traditional morphological and biochemical markers 1,2 . Among the DNA markers, polymerase chain reaction (PCR) based markers using arbitrary primers, such as, RAPD, have been widely used for investigating genetic relatedness and diversity in plant population and cultivars 3-9 . It offers a simple, efficient and economic means for cultivar identification and diversity analysis. In the present study, the assessment of genetic diversity and the relationship among mungbean genotypes was carried out through RAPD analysis. Materials and Methods A total of 39 cultivars of mungbean from wide geographical origin and representing a wide spectrum of variability were selected randomly for the present study (Table 1). The material was planted in the field for seed multiplication in the kharif (2006-07). Each genotype was screened carefully in the field for their genetic purity. The genotypes were used for assessing the polymorphism for random amplified polymorphic DNA (RAPD) markers. Genomic DNA was isolated from 15-d-old seedling by a modification of Doyle and Doyle 10 method and Saghai-Maroof et al 11 . PCR conditions were optimized for uniform, clearly visible and dense bands. PCR amplifications were performed using Palm Cycler (Corbett Australia). Based on the results of pilot experiments run for optimization of PCR conditions, the PCR reaction mixture contained: 1U of Taq DNA polymerase, 1× PCR buffer, 0.2 μ M primer, 20 ng of DNA template, 200 μ M of dNTPs mix and 1.5 mM of _____________________ *Author for correspondence: Tel: 91-1662-289202 E-mail: drsubhadra55@yahoo.co.in