Abstract

PEREIRA DA COSTA, J.H. et al. Influence of exotic genes on tomato fruit shelf life and weight. Agriscientia [online]. 2009, vol.26, n.1, pp.7-13. ISSN 1668-298X.

Fruit shelf life (SL) is an important trait in the cultivated tomato (Solanum lycopersicum) that might be increased by introgressing exotic genes. However, this approach causes a reduction in fruit weight (W). The objective of this research was to analyse the inheritance patterns of both traits in an interspecific cross, in order to subsequently design the appropriate breeding strategy. Plant material included cv. Caimanta, accession LA722 of the exotic S. pimpinellifolium, and their F₁, F₂, BC_I.1 (F₁ x LA722) and BC_I.2 (Caimanta x F₁) generations. The genetic parameters, degree of dominance (d/a), broad sense heritability (H²), and narrow sense heritability (h²) were estimated for SL and W, and the phenotypic (r_p) and the genetic (r_g) correlations among them were calculated. The d/a were -1 and -0.86, H² were 0.35 and 0.45, and h² were 0 and 0.52, for W and SL respectively. The r_p was 0.36 (p < 0.01) and r_g was - 0.86. Genetic variance was generated for both fruit weight and shelf life from this interspecific tomato cross, the additive variance component being important for SL but null for W. Also, a strong association among opposite gene effects was detected for both traits.

Keywords : Genetic analysis; Plant breeding; Solanum section Lycopersicon; Plant genetic resources.

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