PAMPANNA YVISHWANATH A S2020-07-082020-07-082019-07-30150http://krishikosh.egranth.ac.in/handle/1/5810148849The present investigation entitled “Studies on heterosis and combining ability for yield and yield attributes in tomato (Solanum lycopersicum L.)” was carriedout at New Orchard, Main Agricultural Research Station, Raichur, Karnataka, during the year 2018- 19. Six genotypes (inbred lines) of tomato were selected on the basis of contrasting morphological and quality characters. All six parents viz., P1, P2, P3, P4, P5 and P6 were crossed by following full diallel fashion with reciprocals, to obtain 30 F1 hybrids. The experiment was laid out in Randomized Block Design, with two replications. All the 30 F1 hybrids along with their parents and standard check (Indam 13201) were raised during Kharif, 2018. Results revealed that, parent P1 and P6 exhibited the highest mean fruit yield per plant. Among the hybrids, P5 × P6, P5 × P3 and P4 × P3 recorded the highest mean total yield per plant. Estimates of general combining ability effects showed that parent P6 followed by P5 were the best general combiner as they showed significant gca effects in desirable direction. The cross P5 × P6 was the only cross which showed high sca as well as high per se performance for majority of the yield and yield contributing traits. The standard heterosis ranged from ˗18.27 (P4 × P6) to 65.38 per cent (P5 × P6). Out of 30 cross combinations, three cross combinations P5 × P6 (65.38 %), P4 × P3 (33.01 %) and P5 × P3 (30.77 %) showed significant and positive standard heterosis for fruit yield per plant. Fruit yield per plant had positive and highly significant association at both phenotypically and genotypically with plant height, number of branches per plant, number of clusters per plant, number of fruits per plant and fruit lengthennullThesis