BADAYA, S. N.KAPADIA, SHAILESHKUMAR ISHWARBHAI2018-06-012018-06-012002http://krishikosh.egranth.ac.in/handle/1/5810048499Fifteen females were crossed with five pollinators in a line X tester mating design. The resulting 75 hybrids alongwith 20 parents were grown in a Randomized Block Design with three replications at Plant Breeding Research Farm, Vegetable Research Unit, Gujarat Agricultural University, Anand during Summer and Kharif seasons of 1998-99 and were evaluated for 12 characters. The objective of the study was to investigate the mean performance of parents and hybrids, magnitude of heterosis, components of genetic variances, general combining ability effects of the parents and specific combining ability effects of the hybrids over environments. The analysis of variance, in general, revealed significant differences among genotypes, parents, females vs males, parents vs hybrids and hybrids for fruit yield. early yield, yield components, and the two traits for resistance. The presence of genotypes x environments and hybrids x environments interactionswas observed for all the characters except for days to flower and root-knot index. HRB-55, Sel,-2, KS-404 and KS-312 among females; Pusa Sawani and HRB 9-2 among males and KS-312 x HRB 9-2, Padra 18-6 x HRB 9-2, IC-169354 x HRB 9-2 and Red-1'Long x Dafftari-9 among hybrids expressed the highest mean fruit urtd yield on pooled basis and were also superior for many yield components and resistant/tolerant to YVMV disease and root-knot nematodes. Highly significant and high magnitude of heterosis was observed for all the characters but the hybrids varied in magnitude of heterosis for different characters over environments. In general, superior parents gave superior hybrids and higher magnitude of heterosis in hybrid combinations. The highest magnitude of heterosis was observed for early yield per plant, number of fruits per plant, ftult yield per plant, number of branches per plant and YVMV incidence in that order, A number of crosses showed desirable/significant negative heterosis for days to flower, root-knot index and YVMV incidence. The crosses, KS-312 x HRB 9-2, Padra 18-6 x HRB 9-2, IC-169354 x HRB 9-2 and Red-1'Long x Dafftari-9 exhibited highest magnitude of standard heterosis for fmit yield on pooled basis and were also relatively high in individual environments.enPLANT BREEDING AND GENETICS, AGRICULTUREA STUDYThesis