Studies on Character Improvement in Tomato (Solanum lycopersicum L.) by Heterosis

Most of the tomato varieties in Bangladesh are of inbred type and produced low yield indicating need to develop high yielding variety through the hybridization. Heterosis breeding is used to improve yield and quality of tomato because traditional methods cannot be used to achieve this goal. A half diallel design was employed to develop F1s from seven parents of winter tomato. 21 F1s along with their parents were evaluated for yield and quality traits. Heterosis analysis revealed that heterotic vigor was present for growth and yield characters among hybrids. Heterosis for better parent was negative for days to flowering, days to harvest, harvest duration, number of locules, and number of seeds per fruit but positive for fruit set, number of fruits per plant, yield per plant, pericarp thickness and TSS. None of the hybrid was heterotic for all characters simultaneously. The hybrids G5, G13, G16, G17, G18, and G20 had 25.73, 19.92, 39.20, 36.49, 53.77, and 50.31% higher heterosis compared to the better parent, respectively, for fruit yield per plant as well as for many other yield contributing traits. High heterosis for yield appears to be the consequence of heterosis of yield attributing traits; therefore, these hybrids offer scope of developing improved commercial lines through heterosis breeding.