Inheritance of morphometric and quality fruit traits, and selection of transgressive segregants derived from crosses of contrasting tomato accessions

ASPRELLI P.D.; CALISE C.; FERNÁNDEZ D..; VARGAS E.V.; PERALTA I.E.

Cornell

Congreso; SOL INTERNATIONAL ONLINE MEETING 2020; 2020

Sol Genomics Network

Two half-sibs were developed crossing tomato accessions of contrasting fruit colour, size and shape, from La Consulta INTA Germplasm Bank, Mendoza, Argentina. Parentals, F1 and F2 generations were evaluated through 13 morphometrical and quality fruit traits, and 18 carotenoid and chlorophyll pigments content. Segregant frequencies for pericarp colour suggest three genes with complementation and epistatic effects. Allele contributions and dominance ratios shows partial, complete and overdominance effects for different traits, and also differential correlations between them. A total of 77 transgressive F2 individuals were selected for its fruit attributes, and families were derived by selffing until F5 under a genealogical selection scheme focussed on round fruits, thick pericarp and high soluble solids content. F5 individuals were pooled by their fruit colour in red, pink, orange, dark and light yellow, brown, purple, and green groups. Fruit selection was stabilized at around 25 g weight, height-width ratio of 1.0, soluble solids rise up from 5.6-6.5 ºBrix in F1 to 8.8 ºBrix in F5, and pericarp width increased up to 27%. Broad sense heritability values of F5 colour-groups rise down with respect to F2 for size, shape and color uniformity. Each F5 colour-group shows different patterns of heritability reduction, retaining considerable variability for pigments, soluble solids content and pericarp thickness. A better understanding of the genetic components of tomato fruit attributes, and associations between agronomic traits and quality, allowed selecting individuals of outstanding characteristics for differential and gourmet markets.