SHARMA, H. DEVSINGH, SHALINI2020-09-222020-09-222020-08https://krishikosh.egranth.ac.in/handle/1/5810151777ABSTRACT The present investigation entitled “Studies on heterosis, combining ability and gene action for horticultural traits in brinjal (Solanum melongena L.)” was conducted at Experimental Farm, Department of Vegetable Science, Dr YS Parmar University of Horticulture and Forestry, Nauni, Solan-173 230 (HP) during the years 2017, 2018 & 2019. The experimental material for the present study consisted of fifteen lines, three testers, their resultant forty five crosses developed by Line × Tester mating design and three standard checks. All the parents, their hybrids and the three standard checks were planted in a Randomized Block Design for their evaluation in Kharif, 2019. The observations were recorded on eighteen different traits viz., Days to 50% flowering, Days to first picking, number of fruits per plant, fruit length (cm), fruit breadth (cm), fruit volume (cc), fruit weight (g), number of leaves per plant, plant height (cm), plant spread (cm), number of primary branches per plant, stem girth (cm), fruit yield per plant (g), shoot and fruit borer infestation (%), incidence of fruit rot (%), TSS (0B), ascorbic acid content (mg/100g) and total phenol content (mg/100g). Inheritance of resistance to shoot and fruit borer was also studied by observing the segregation pattern of different generations (F2, B1 and B2) using chi-square analysis. The analysis of variance indicated highly significant differences among all the genotypes for all the traits studied. The experimental results revealed that the lines IVBL-116- 131, NBJ-19, CO-11, DRNKV-02-104, DBR-8, and testers PPL and PPC were superior based on their mean performance and general combining ability. Therefore, they can further be used in multiple crosses and their segregating population. Based on mean performance, heterosis per cent and specific combining effects five most promising cross combinations were NBJ-19 × PPL, DRNKV-02-104 × PPC, DBR-8 × PPC, IVBL-116-131 × PPC and CO-11 × PPC which performed well for majority of traits. Hence, these hybrid combinations can further be tested at multiple locations and could be utilized for future hybrid brinjal breeding. Gene action studies indicated predominance of non additive gene action in governing all the traits suggesting exploitation of hybrid vigour and developing hybrids for improvement of horticultural traits in brinjal. Chi-square analysis revealed that in all the three crosses F2 generation segregated as 15 infested to 1 non-infested in both shoots and fruits revealing the presence of duplicate gene action and the test cross i.e., B1 segregated in 1:1 ratio whereas, in B2 reverse pattern of inheritance was observed suggesting that digenic recessive genes were involved in governing the inheritance of resistance to shoot and fruit borer. Keywords: Brinjal, Solanum melongena, heterosis, combining ability, gene action, inheritance of resistance, shoot and fruit borer, horticultural traits.EnglishThesis