STRAWBERRY FRUIT SIZE INHERITANCE AS DEPENDENT ON ACHENE NUMBER AND FLESH MASS PER ACHENE

Abstract

In conditions of central Russia, a series of studies were undertaken over 1998-2010 to explore peculiarities of strawberry fruit size inheritance, using progenies raised from crosses of several cultivars with two wild clones as testers and with each other. Notable amounts of seedlings from crosses of cultivars with a very small-fruited clone of F. ovalis (0.5 g) produced larger fruit compared with progenies of F. virginiana subsp. platypetala (1.3 g). In two subsequent studies where only large-fruited cultivars/lines were used in crosses, achene number per fruit and per cm2 and flesh mass per achene were measured in both parent cultivars and their progenies. The features have been determined by independent genes. In some progenies, genes contributing to flesh mass per achene acted as dominant, while in others (from crosses with ‘Feierverk’, ‘Festivalnaya’) they were suppressed by other genes. This trait is a result of complex interactions of genes, including modifiers, the contributions of which differ. Values of mean achene number per berry were, in most progenies, intermediate between those of parent cultivars, while low flesh mass per achene, typical of some genotypes, predominated in their progeny. High values of flesh mass per achene were frequently related to softer fruit and earlier fruit ripening. Genotypes that produced very large fruit, combining abundant achenes and high flesh mass per achene, needed longer periods of time for plant development and fruit growth. A few of them were able to produce very high yields, but only in one of two cropping seasons.