XVI International Botanical Congess
The basic mechanism of progress evolution in Rosaceae is the rise of primitive cariotypes ploidy level. We established the phenomenon of female and male 2n gametes forming and development in all the investigated Fragaria species (2x, 4x, 6, 8x). Female 2n gametes development can be both apomictic or sexual. If sexual the ploidy level of progeny rises up. The cytoembryological studies demonstrated that meiotic segregations anomalies connected with spindle formation and the cytokinesis damaging in mother cell of megaspore can lead to the egg cells unreduction. The diploidization of normal egg-cells in meiotic megagametophytes takes place by the acytokinetic. The elimination one of the meiotic division causes the 2n male gametes development. 2n gametes participation in the sexual process provides the possibility of autosyndesis in progeny plant when spontane crossing between the species with different ploidy levels.