Studies of heterosis and inbreeding depression for growth parameters in tomato hybrids (Solanum lycopersicum L)

Abstract

The experiment took place over three consecutive Rabi seasons at the Vegetable Research Farm (South Block), Department of Horticulture, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh. The experimental material consisted of 13 genotypes, including 10 lines, 3 testers, and one standard check (Pant T1). These genotypes were chosen based on their performance for various traits. A Line Tester design was used to evolve 30 F1s and 30 F2s from these 13 genotypes. An investigation was conducted on the three growth parameters, specifically Days to 50% flowering, plant height, and number of primary branches per plant, to examine heterosis and inbreeding depression. The cross VRT-18×H-86 exhibited the highest significant negative mid-parent, better parent, and standard heterosis for days to 50% flowering, which is advantageous in terms of early flowering. Additionally, it displayed the lowest level of inbreeding depression. The cross VRT-51×SEL-7 exhibited the highest level of heterosis in terms of plant height, with a significant magnitude of 44.50%. On the other hand, the cross H-24×SEL-7 displayed the lowest level of inbreeding depression, with a magnitude of 17.48%. When examining the number of primary branches per plant, we found that Kashi Aman×SEL-7 exhibited the highest level of heterosis at 48.40%. On the other hand, the cross VRT-01×ToLcv-41 showed the lowest level of inbreeding depression at -35.35%, which is quite desirable. These findings suggest that these specific crosses have the potential for further selection in varietal development programmes.