Discrepancy of pollen germination and pollen tube growth at different mature degree of pistil in sweet cherry

Pollen germination and pollen tube growth in the styles of two sweet cherry cultivars, Moreau and Lapins, were examined after self- and cross- pollination among different florescence respectively. At intervals of 12, 24, 48, 72 and 96 h after pollination, the pollen germination and pollen tubes subsequent growth in the styles was observed with fluorescence microscope after fixed in FAA and coloration. Results showed that the best pollen germination percentage of the self-pollinated Moreau and Lapins, and cross-pollinated Moreau × Lapins all occurred on the day of anthesis. The best pollen tube growth was also of those pollinated on the anthesis. But the pollen tube growth of self-pollinated Moreau was in contrary. Its best pollen tube growth was that pollinated 4 d before flowering, then that of pollinated 4 d after flowering, while that pollinated on anthesis was the worst. So it is believed that the self-incompatibility of sweet cherry was correlated with the development of the pistils. Pollination carried out at pre-flowering stage and delayed-pollination could overcome the self-incompatibility to some extent, but pollination at pre-flowering day should be better.