Combining ability and patterns of inheritance for plant and fruit traits in Japanese quince (Chaenomeles japonica)

Phenotypic variation and pattern of inheritance was investigated for plant and fruit traits in Japanese quince (Chaenomeles japonica, Maloideae). Japanese quince is a minor fruit crop in Latvia and Lithuania, and is presently being developed for production of juice, aroma and fruit fibre in Sweden and Finland. General and specific combining ability was estimated for five plant vegetative traits, eight fruit yield and morphology traits, and five fruit biochemistry traits in a study population consisting of 14 hybrid families. Thorniness seems to be controlled primarily by a single locus. All other traits studied appear to be governed primarily by additive genes, as judged from general combining ability estimates. Significant specific combining ability (SCA) was detected for yield, plant height and some fruit traits. However, the relative contribution of SCA to the overall genetic variance was in general low. An efficient breeding strategy for Japanese quince could therefore be based on recurrent selection.