Unique features of the female gametophyte development of strawberry Fragaria x ananassa Duch.

Plant development by the apomixis process has a significant impact on agriculture and food production. Analysis of the amphimictic and apomictic modes of reproduction is important for breeding new varieties and control of high-quality seeds and fruits. Fragaria x ananassa is one of the most often cultivated plants characterized by a wide assortment of commercially available cultivars. The aim of this study was to describe all phases of female gametophyte development in F. x ananassa cv. 'Mount Everest' and 'Senga Sengana'. In this paper, we report both typical stages of the sexual pathway of development and events indicating the possibility of the apomictic mode in the examined strawberry ovules. The beginning of the F. x ananassa reproduction process is distinguished by the presence of a multicellular archespore. With the progress in the development, the particular features of the ovule show a tendency towards simultaneous formation of multiple megasporocytes and embryo sacs in the same nucellus. Our results may be taken as evidence of the occurrence of facultative apomixis in both examined cultivars of F. x ananassa.