Análise genética de acessos de tomateiro com genes pleiotrópicos que modificam caracteres pós-colheita de frutos

Plants of five tomato accessions ( Lycopersicon esculentum Mill.) derived from diallel crossing, carrying modifier genes for normal fruit ripening and their F1 hybrids, except reciprocals, were evaluated. The pleiotropic effect of ‘stolid’ mutant and the nature and magnitude of genetic effects involved in the determination of those traits are provided. Although ‘stolid’ mutant increased shelf life, fruit firmness and the levels of carotenoid pigments, soluble solids contents decreased. Excepting fruit pH, all traits followed the additive-dominant model with additive genetic effects. Dominance deviations were also important, with the exception of fruit firmness. Additive genetic effects were more important for shelf life and titratable acidity and there was no predominance of any other particular genetic effect for remaining characteristics. Recessive genes were very important to increase shelf life and fruit firmness, while dominant genes increased the level of soluble solids and titratable acidity. Regression analysis of W i on V i , showed that cv. Santa Clara and ‘stolid’ mutant were divergent in shelf life, firmness and soluble solids of fruits. Selection can only be efficient for shelf life. Cross P 1 (‘stolid’ mutant) with P 5 (BGH-6913 - nor ) has been shown to favour an increase of post-harvest conservation