Comparison of pear pollen tube growth in style and fruit set after self-and cross-pollination in different floral development stage

In this study, two pear cultivars with different self-incompatible degree, Housui and Kikusui, were self-pollinated and Housui was pollinated with the pollen of Kikusui in their different floral development stage. Pollen germination and tube growth state were observed with fluorescence microscopy. The results were as follows. Pollen germination rate in vivo was high both for self-pollination and cross-pollination at or after anthesis; There were some difference in pollen tube growth speed and the place where pollen tube growth arrested among different pollination type, pollen tube growth being slower and shorter in Housui self-pollination, faster and longer in Kikusui self-pollination, fastest and longest in cross-pollination. For self-pollination, pollen tube length was longer both on the fourth day before and fourth day after anthesis. Pollen tube was very short when they were pollinated sixth day before anthesis. These were consistent with the result of fruit set in field pollination.