Breeding value of selected dessert strawberry (Fragaria × ananassa Duch.) cultivars for ripening time, fruit yield and quality

A half-diallel mating design (Griffing’s method IV) among 13 dessert strawberry parental genotypes (‘Figaro’, ‘Salsa’, ‘Palomar’, ‘Granda’, ‘Camarosa’, ‘Elianny’, ‘Aromas’, ‘Diamante’, ‘Portola’, ‘Charlotte’, ‘San Andreas’, ‘Monterey’ and ‘Albion’) was constructed to study the breeding value in terms of general and specific combining ability (GCA and SCA) effecting several important horticultural traits. The crossbreeding was conducted during the winter of 2010/2011 in a greenhouse (temperature of 20 °C and supplemental lighting of 16 h). The 6 week-old progenies of 78 sibling families were planted to the field experiment in July 2011. A randomized complete block design, with four replicates, each composed of 15 seedlings was used. Fruit ripening time, marketable fruit yield and fruit quality (weight, attractiveness and firmness, soluble solids, and ascorbic acid content) were recorded in 2012 and 2013. Data analysis was performed based on the fixed Griffing’s model. The analyzed traits were determined by both additive and non-additive genetic effects. Inheritance of the traits such as fruit firmness, mean fruit weight, and soluble solids content, was predominantly determined by additive effects. The strongest positive phenotypic and genetic correlations were observed between fruit weight and fruit attractiveness, whereas the negative ones—between fruit ripening time and fruit weight. The highest breeding value based on GCA was estimated for cultivars: ‘Palomar’—for fruit weight and attractiveness, and the soluble solids content, ‘Figaro’—for fruit weight and soluble solids content, ‘Camarosa’—for marketable fruit yield and fruit weight, ‘Elianny’—for fruit weight and attractiveness, and ‘Charlotte’—for marketable fruit yield and ascorbic acid content. The lowest breeding value exhibited cultivars ‘Albion’ and ‘San Andreas’. The following hybrid families have shown the highest positive SCA effects for two or more traits with no negative effects: ‘Aromas’ × ‘Salsa’, ‘Monterey’ × ‘Figaro’, ‘Palomar’ × ‘Camarosa’, ‘Portola’ × ‘San Andreas’ and ‘Portola’ × ‘Charlotte’.