Estimation of breeding value of blackcurrant genotypes for growth vigour, plant habit and their susceptibility to fungal diseases.

The study was conducted in 2012–2014 at the Experimental Orchard of the National Institute of Horticultural Research in Skierniewice, central Poland. The aim of the research was to assess the breeding value, based on the general combining abilities (GCA), specific combining abilities (SCA) and reciprocal (RE) effects, of six dessert parental forms of blackcurrant for plant growth vigour, plant habit and resistance to fungal diseases: Podosphaera mors-uvae (causal agent of powdery mildew of currant), Drepanopeziza ribis (leaf anthracnose) and Cronartium ribicola (white pine blister rust). The plant material consisted of seedlings of F1 generation obtained by crossing of six blackcurrant genotypes: ‘Bona’, ‘Ceres’, clone D13B/11, ‘Sofiivska’, ‘Vernisazh’ and ‘Big Ben’ in a diallel design according to Griffing’s Method III.It was shown that the cultivars ‘Big Ben’, ‘Sofiivska’ and ‘Vernisazh’ had significantly positive GCA effects for growth vigour and resistance of plants to powdery mildew, whereas ‘Ceres’ – for plant habit, which indicated their high breeding value for these traits. The significantly positive SCA values were estimated for the hybrid family: ‘Big Ben’ × ‘Ceres’ for low susceptibility of plants to powdery mildew and anthracnose. Statistically significant effects for reciprocal crosses (RE) were obtained only for few hybrid families.