Link of winter hardiness of strawberry’s parent genotypes with inheritance of number of inflorescence and fruit size

Abstract

The aim of the work was to find out specificity of inheritance of inflorescence number per plant and mean fruit mass in strawberry under conditions of a region with cold winters and poor snow cover in dependence on winter hardiness level of parent cultivars. Data obtained in three studies, aimed on evaluation of parent cultivars differing in winter hardiness and yield components values and their progenies from crosses with small-fruited wild species and between each other, served as the material. Features of inheritance of studied characters were established, using estimation of deviations of average values of inflorescence number per plant and fruit mass of progeny from average values between parent cultivars. Winter hardiness of parent genotypes had effects on the inheritance of yield components. Winter hardy and high-yielding cultivars Festivalnaya, Feierverk and Alpha passed of the character of high inflorescence number to their hybrids which was accompanied by a significant negative deviation of mean fruit mass in the progenies from its average value of two parent cultivars. Insufficient winter hardiness of flower buds in ‘Rubinovy Kulon’ led to negative deviations of inflorescence number in its progenies, but the inflorescence losses in the descendants were compensated by average fruit mass increase. Breeding for yield and large fruit was more efficient when winter hardy cultivars that produced numerous inflorescences were crossed with cultivars that lost a part of inflorescences during overwintering and compensated the losses by fruit mass increasing. Crossing of high-yielding mid-season and mid-late cultivars with large-fruited early to mid-season ones (with mean fruit mass higher than 11.0 g) is more promising compared to crossing of cultivars with close components values and terms of fruit maturing. This ensures obtaining progenies with an improved balance between inflorescence number (6.5-8.5 in first cropping year) and fruit mass (exceeding 12.0 g) at high enough winter hardiness.