Observation on characteristics of floral differentiation and development of sweet cherry in late phase

Abstract：In order to grope for the mechanism in fruiting problem of sweet cherry （Prunus avium L. ） in southern areas of China, three experiments, including variety comparison, location comparison and artifi- cial environmental simulation, had been carried out from the stage of post-defoliation to the stage of post- bloom for observation of the characteristics of differentiation and development of floral bud of sweet cherry. The results showed that the floral bud of sweet cherry had ultimately displayed the basic characteristics of differentiation and development in identity at the phases of multi-phenological calendars in the stages mentioned above in those tested varieties which were Zaohongbaoshi, Hongdeng and Lapins cultured in Zhengzhou, and Hongdeng cultured in Yantai, Zhengzhou, and Jinhua, and Zaohongbaoshi cultured in openfield and greenhouse in the period of floral bud differentiation in those three experimental designs. It was argued that the mechanism of fruiting difficulty mentioned above had no relationship with the floral bud differentiation in growth season, and not only the embryo sac in poorly developmental quality which was induced by high temperature before the stage of post-bloom but laso the shortage of chilling accumu- lation should be responsible for the fruiting difficulty.