Sharma, Hem RajRakesh2017-06-032017-06-032016http://krishikosh.egranth.ac.in/handle/1/5810016919The present investigation entitled “Genetic studies for yield and quality traits in tomato (Solanum lycopersicum L.)” was carried out at the Experimental Research Farm, Department of Vegetable Science, Dr. YS Parmar University of Horticulture and Forestry, Nauni, Solan (HP) during Kharif, 2014-15 and 2015-16 to know the extent of heterosis, assessing combining ability and generating information on gene action. Six diverse tomato genotypes were crossed in a diallelb fashion (excluding reciprocals) during Kharif2014-15 and in the next year fifteen crosses alongwith 6 parents and one standard check (Naveen 2000+) were evaluated in RCBD. Analysis of variance showed significant differences among all the genotypes for all the characters under study. The genotypes, EC-1055 and EC-1057 among parents while Solan Lalima x EC-1057 and Solan Lalima x EC-1058 among cross combinations were found superior for earliness. Heterobeltiosis for fruit yield and quality traits was recorded significantlypositive in Solan Lalima x EC-1055, Solan Lalima x EC-1057 and Solan Lalima x EC-1058. Maximum negative heterosis for buck eye rot incidence and alternaria blight severity was observed in Solan Lalima x EC-1055, Solan Lalima x EC-1057 and Solan Lalima x EC-1058. For yield and component traits Solan Lalima was good general combiner. Solan Lalima x EC-1055, Solan Lalima x EC-1057 and Solan Lalima x EC-1058 were good specific combiners for fruit clusters per plant, number of fruits per cluster, number of fruits per plant, harvest duration and fruit yield traits. Solan Lalima and UHF-55 were good general combiners for total soluble solids, lycopene content and ascorbic acid content. Cross combinations viz.Solan Lalima x EC-1055, Solan Lalima x EC-1057 and Solan Lalima x EC-1058 were good specific combiners for all quality traits. Solan Lalima was good general combiner for buck eye rot incidence, alternaria leaf blight severity, septoria leaf blight severity and fruit borer infestation. The estimates of σ 2 g/σ 2 s (predictability ratio) were found to be < 1 for almost all the traits included in this study except for plant height, fruit size, buck eye rot incidence and fruit borer infestation indicated predominance of non additive gene action.enFruits, vegetables, crossing over, diseases, heterosis, biological phenomena, yields, planting, genes, additivesThesis