Studies on mode of gene action for fruit quality characteristics governing shelf life in tomato (Solanum lycopersicum L.)

Extending the shelf life of tomatoes is very essential for the reduction of great losses in quality and quantity. Knowledge of genetic architecture of the shelf life contributing traits and their inheritance pattern in different genetic backgrounds is a key issue for the development of high yielding and good shelf life cultivars. An investigation was undertaken to estimate the nature and magnitude of gene action for 18 fruit quality and yield traits governing shelf life through six generations (P-1, P-2, F-1, F-2, B-1, and B-2) mean analysis in the F-1, Arka Vikas x Red ball cross. Inadequacy of additive-dominance model in explaining the inheritance of fruit quality traits governing shelf life revealed the significance of joint-scaling test and presence of epistasis. The dominance x dominance interaction was larger than the additive x additive and additive x dominance effects and the dominance component was greater than the additive component. Duplicate epistasis played a greater role than complementary epistasis. Shelf life and its contributing traits such as TSS, lycopene, titratable acidity, pH, ascorbic acid, fruit diameter, fruit firmness, locule number, and yield per plant are controlled by dominant genes with duplicate epistasis. Simple selection procedure in the early segregating generation for shelf life and its contributing traits is ineffective in improving genetic gain as dominance and dominance x dominance gene effects are non-fixable. The additive and dominance components successfully are exploited in the advanced segregating population by evaluating a large number of families. One to two cycles of bi-parental mating followed by intensive selection lead to dissipation of dominance and enhance the frequency of genes with increasing effects on the expression of fruit quality traits governing shelf life. Both additive and dominance with a predominance of dominance effects of genes are important in the inheritance of fruit quality traits governing shelf life.

Automated summary

The study revealed that shelf life and its contributing traits in tomatoes are primarily controlled by dominant genes with duplicate epistasis. Simple selection procedures in the early segregating generation are ineffective in improving genetic gain, as dominance and dominance x dominance gene effects are non-fixable. Exploiting both additive and dominance components in the advanced segregating population can lead to dissipation of dominance and enhance the frequency of genes with increasing effects on the expression of fruit quality traits governing shelf life.