GENETIC VARIABILITY AND CHARACTER ASSOCIATION IN F 2 GENERATION OF TOMATO (Solanum lycopersicum L.)

Abstract

The experiment was conducted at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh during the Rabi season of 2019 under field condition to identify the variability, correlation and path coefficient analysis by considering twenty (20) yield contributing characters using thirty-nine (39) crossing genotypes in F 2 generation of tomato (Solanum lycopersicum L.). The genotype G 4 ×G 5 showed the highest number of flowers per cluster but the genotype G 6 ×G 5 showed the highest number of fruits per cluster and the genotype G 3 ×G 1 showed the highest number of fruits per plant. The genotype G 1 ×G 4 showed the highest fruit diameter, locule number, individual fruit weight (61 g) and fruit yield per plant (4.62 kg) but lowest total soluble solids, pH and moisture percentage. The genotypes G 6 ×G 7 and G 7 ×G 6 showed earlier period of days to 50% flowering (72 DAT) and first fruiting (49.33 DAT) where the earlier period of days to maturity was found in G 2 ×G 5 (89.67 DAT), respectively. Narrow gap between PCV and GCV for days to 50% flowering, days to maturity, fruit length, fruit diameter, skin diameter, locule number, total soluble solids, pH, relative water content, moisture percentage, individual fruit weight and fruit yield per plant suggested that environmental influence were minor on the expression of the gene controlling these traits and selection based upon the phenotypic expression of these characters would be effective for the improvement of this crop. High heritability coupled with high genetic advance in percentage of mean for fruit length (cm), fruit diameter (cm), skin diameter (mm), locule number, total soluble solids, pH, relative water content, individual fruit weight and fruit yield per plant were obtained, suggesting that the heritability of these traits is due to additive gene effects and selection may be effective in early generations for these traits. Yield per plant showed positively significant association with number of flowers per cluster, fruit length, fruit diameter, locule number, individual fruit weight for both genotypic and phenotypic level, indicating that a possible increase in these traits tends to increase in fruit yield per plant. A positive direct effect was obtained for days to first fruiting, number of branches per plant, number of clusters per plant, number of fruits per cluster, skin diameter, locule number, relative water content, moisture percentage and individual fruit weight on fruit yield per plant. Therefore, considering the agronomic and genetical performance, the G 1 ×G 4 genotype for high yield, G 6 ×G 7 or G 7 ×G 6 genotype for the consumption of green fruits and G 2 ×G 5 genotype for short durated ripen fruits might be suggested for further selection in next generation that would be effective in future for breeding program.