Yield, quality and conservation of heterozygous tomatoes in alcobaça, nonripening and ripening inhibitor loci

Abstract

Thie objective of this work was to evaluate yield, quality and postharvest conservation of tomatoes, to compare the effects promoted by the alcobaça (nor^A), nonripening (nor) and ripening inhibitor (rin) alleles, in heterozygosis, singly or in double combinations on hybrid tomato fruits. Ten treatments were evaluated: seven experimental nearly isogenic hybrids of FloraDade x Tropic background or reciprocal with nor⁺/nor^A, rin⁺/rin, nor⁺/nor, nor/nor^A, nor⁺/nor^A rin⁺/rin and nor⁺/nor rin⁺/rin genotypes, and three commercial checks (FloraDade, Tropic and Carmen F₁). Oppositely to the genotypes rin⁺/rin and nor⁺/nor, the genotype nor⁺/nor^A did not significantly extend the firmness of the fruits in postharvest. The double mutant genotypes nor^A/nor, nor⁺/nor^A rin⁺/rin and nor⁺/nor rin⁺/rin were efficient in delaying firmness loss and the evolution of fruits colouring; the effects of loci nor⁺/nor^A and rin⁺/rin, together, underwent significant deviations relatively to the sum of these loci effects, when acting singly, in the sense of enhancing those delays. Use of heterozygous hybrids in the double combinations among loci nor^A, nor and rin proved advantageous for providing firm fruits with a longer postharvest lifetime, as compared with the hybrids carrying these loci singly. The quality of double mutant fruits was not restricted by the delay in the evolution of red coloration.