~ 2385 ~ International Journal of Chemical Studies 2018; 6(5): 2385-2390 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2018; 6(5): 2385-2390 © 2018 IJCS Received: 21-07-2018 Accepted: 24-08-2018 Ranjana Patial Department of Crop Improvement, COA, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur Himachal Pradesh, India RK Mittal Department of Crop Improvement, COA, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur Himachal Pradesh, India VK Sood Department of Crop Improvement, COA, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur Himachal Pradesh, India Correspondence Ranjana Patial Department of Crop Improvement, COA, CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur Himachal Pradesh, India Estimation of heterosis for seed yield and yield contributing traits in urdbean [ Vigna mungo (L.) Hepper] Ranjana Patial, RK Mittal and VK Sood Abstract Heterosis over mid parent, better parent and standard check were determined for yield and yield components in a line x tester design among urdbean genotypes during kharif 2017. Twelve hybrids i.e. IC-282007 x Him Mash-1, IC-436910 x HPBU-111, IC-398956 x HPBU-111, IC-398956 x Him Mash-1, IC-413306 x Him Mash-1, IC-413305 x HPBU-111, IC-413305 x Him Mash-1, IC-281990 x HPBU-111, IC-281995 x Him Mash-1, IC-343885 x HPBU-111, IC-343943 x HPBU-111 and IC-281984 x HPBU- 111 produced high heterotic effects over mid, better parent and standard check for seed yield per plant. Five cross combinations viz., IC-398956 x HPBU-111, IC-281990 x HPBU-111, IC-281995 x Him Mash-1, IC-343885 x HPBU-111, IC-343943 x HPBU-111 had shown significant and positive value over mid, better parent and standard check for seed yield per plant as well as for protein content, hence could be a good source for developing high yielding quality urdbean varieties. Keywords: estimation, heterosis, contributing traits, urdbean, Vigna mungo Introduction The discovery of hybrid vigour by Shull (1908) [17] opened a new era in genetic improvement of crop plants which is now referred as heterosis breeding. Genetically and geographically diverse genotypes are the main pre-requisites in the development of heterotic combination (Mole et al. 1962) [12] . The phenomenon of heterosis has provided the one of the most important genetic tool in improving yield of self as well as cross pollinated species. Heterosis is a valuable expression that often results from genetic recombination (Lamkey and Edwards 1999) [10] . Extent and magnitude of heterosis present in hybrids is important for any crop improvement programme. In grain legumes, the heterosis is generally due to dominance gene effects but also sometimes due to epistatic interaction (Sethi 1975) [16] . In self pollinated crops, it is possible to exploit such genetic manifestation only with a potentially workable sterility mechanism, if available. A substantial component of epistatic interaction for agronomic and growth characters has been found in urdbean (black gram: Vigna mungo) belonging to the fixable epistasis, viz, additive x additive (Nijhawan 1975) [15] . The information regarding epistatic interaction is useful in planning a breeding program for development of pure lines with enhanced yield potential. The presence of heterosis in food legumes has also been demonstrated by Kant and Srivastava, (2012) [8] . Little information about heterosis and gene action is available in blackgram. The exploitation of heterosis in urdbean has not been commercialized due to limited extent of out crossing (Singh 2000) [18] . However, highly heterotic crosses can be used for development of high yielding pure line varieties in a self- pollinated crop like urdbean. Thus, the purpose of the present study was to determine the extent of heterosis among various cross combinations of urdbean genotypes diverse in seed yield and yield attributes. Material and Methods Twenty-nine genetically diverse genotypes of urdbean (Vigna mungo L.) were crossed in Line x Tester mating design. Twenty-seven (Lines) were used as a female (IC-281980, IC-282007, IC-282008, IC-436910, IC-281989, IC-398973, IC-281982, IC-282001, IC-398956, IC- 413306, IC-413307, IC-281993, IC-343962, IC-413305, IC-398998, IC-281992, IC-413304, IC-436852, IC-282002, IC-281990, IC-281995, IC-343885, IC-343947, IC-282004, IC-