Electronic Journal of Plant Breeding, 9(4): 1583-1587 (Dec 2018) ISSN 0975-928X 1583 DOI: 10.5958/0975-928X.2018.00197.7 Research Note Genetic variability and correlation studies in black-gram [Vigna mungo (L.) Hepper] L. Priya 1 , M. Arumugam Pillai 1 , D. Shoba 1* , S. Merina Perm Kumari 1 and N. Aananthi 1 1 Agricultural College and Research Institute, Killikulam, Vallanadu-628 252 *E-Mail: shobatnau@gmail.com (Received: 14 Aug 2018; Revised: 26 Dec 2018; Accepted: 26 Dec 2018) Abstract The present investigation was carried out to estimate the genetic variability and genotypic correlation among one hundred and twenty black-gram genotypes for nine quantitative characters. High PCV and GCV were recorded for the traits viz., single plant yield, number of clusters per plant, number of pods per plant and number of primary branches per plant. High heritability coupled with high GAM was recorded for the traits viz., plant height, number of primary branches per plant, number of clusters per plant, number of pods per plant and single plant yield. From the association analysis, single plant yield had negative and significant association with days to 50% flowering and it also exhibited significant and positive correlation with the traits viz., number of pods per plant, number of clusters per plant, number of primary branches per plant and hundred seed weight. Hence, simultaneous selection of the above traits would be more rewarding to bring improvement in black-gram. Keywords Black-gram, Genetic variability, Genetic association Pulses are the major source of dietary protein in the vegetarian diet. Black-gram [Vigna mungo (L.) Hepper] known as urd-bean in India is a short duration, self pollinating, diploid (2n=2x=22) grain legume crop belonging to the family Leguminosae with a small genome size of 0.56g/PC (574Mbp) (Gupta and Gopalakrishna, 2009). Black-gram seeds contain 65 per cent carbohydrates and 25 per cent protein and are consumed as food and the sprouts are used as vegetable and also the seeds possess rich source of minerals and vitamins (Ghafoor et al. 2001). During 2010-11, India produced 1.75 million tons of black-gram with the average productivity of 535 Kg/ ha from 3.26 million hectares (Gupta et al. 2013). The major constraints in black-gram genetic improvement are lack of exploitable genetic variability, absence of suitable ideo type for different cropping systems, poor harvest index and susceptibility to biotic and abiotic stresses and non-availability of quality seeds of improved varieties. It is mainly due to the repeated usage of few parents with high degree of relatedness in crossing programmes (Jayamani and Sathya, 2013). Success of yield improvement largely depends upon the magnitude and nature of genetic variability present in yield contributing traits (Johnson et al. 1955). The association between yield and other yield attributes would be useful for selecting the better genotypes. Association analysis measures the mutual relationship between various plant characters and determines component characters on which selection can be based on improvement in the economically important characters (Hemalatha et al. 2017). Hence, the present study was planned to investigate genetic variability and correlation coefficients to identify superior black-gram genotypes for future exploitation in breeding programmes. The present investigation aimed with the study of genetic diversity using one hundred and twenty germplasm lines collected from different sources viz., National Bureau of Plant Genetic and Resources (NBPGR), New Delhi, National Pulses Research Centre, Vamban, Agricultural College and Research Institute, Madurai and Agricultural College and Research Institute, Killikulam. The field experiment was conducted at Department of Plant Breeding and Genetics at Agricultural College and Research Institute, Killikulam during the year 2017-18. A set of one hundred and twenty genotypes of black-gram were evaluated in Randomized Block Design (RBD) with two replications. Each genotype was raised in a single row of 3 metre length with a spacing of 30 x 10 cm. Observations were recorded on five randomly selected plants in each replication for nine quantitative characters viz., days to 50 % flowering, plant height (cm), number of primary branches per plant, number of clusters per plant, number of pods per plant, number of seeds per plant, hundred seed weight (g), pod length (cm) and single plant yield (g). The various genetic parameters viz., Genotypic