Received: 21 Oct 2021 Accepted: 15 Dec 2021 Revised: 09 Dec 2021 https://doi.org/10.37992/2021.1204.170 Vol 12(4):1244 - 1248 1244 Electronic Journal of Plant Breeding Research Article Estimation of genetic parameters and gene action among crosses of blackgram (Vigna mungo (L.) Hepper) for seed yield and its component traits S. Ragul 1,2 , N. Manivannan 2, *, K. Iyanar 3 , N. Ganapathy 4 and G. Karthikeyan 5 1 National Pulses Research Centre, Tamil Nadu Agricultural University, Vamban-622303, 2 Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore - 641003. 3 Department of Millets, Tamil Nadu Agricultural University, Coimbatore - 641003. 4 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore - 641003 5 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore - 641003 *E-Mail: nm68@tnau.ac.in Abstract Generation mean analysis was employed among the crosses of MDU1 x TU68, VBN6 x TU68 and VBN8 x TU68 of blackgram to partition the mean into various genetic components viz., additive, dominance and epistasis. Five generations viz., P 1 , P 2 , F 1 , F 2 and F 3 obtained from the above three cross combinations were evaluated. The results of the scaling test showed that number of branches per plant in MDU 1 x TU 68, number of branches per plant and number of pods per cluster in VBN 6 x TU 68 and days to fowering and pod length in VBN 8 x TU 68 recorded additive gene action. Hence, these traits can be improved through pedigree breeding and simple selection. All other traits showed non additive model as one or both scales of C and D had signifcance. Days to fowering, plant height, number of branches per plant, number of clusters per plant, pod length, number of seeds per pod, 100-seed weight and single plant yield had additive gene action. In the case of epistasis, days to fowering had additive x additive type gene action in MDU 1 x TU68 and VBN6 x TU68 crosses, while the cross VBN8 x TU68 had additive gene action alone. Hence, the selection at later generations is efective to improve these traits. Other traits had diferential gene action in each cross. Based on the results, it can be concluded that an appropriate selection programme needs to be devised for each cross based on the gene action. Key words: Blackgram, Generation mean analysis, Epistasis, Five parameters, Seed Yield. INTRODUCTION Blackgram (Vigna mungo (L.) Hepper) is one of the important food legume crop of India. It gains its importance due to the short duration nature and wide spread cultivation in India. Blackgram is an excellent source of easily digestible good quality protein and it has its importance in restoring soil fertility through symbiotic soil - nitrogen fxation. Blackgram seeds possess 24-26% of protein, 60% of carbohydrates, 1.5 % of fat, minerals, amino acids and vitamins (Mehra et al., 2016). The choice of an efcient breeding program depends mainly on the knowledge of the type of gene action involved in the expression of the character. Whereas, dominant gene action would favor the production of hybrids, additive gene action indicates that standard selection procedures would efectively bring about advantageous changes in characters (Edwards et al., 1975). Generation mean analysis (GMA) has proved to be a potential technique to estimate gene action through diferent genetic parameters