梨不同花龄自花与异花授粉的花柱内花粉管生长及坐果率的比较

对自交不亲和强度不同的梨品种丰水和菊水的不同花龄花进行自花授粉和丰水×菊水异花授粉后,用荧光显微镜观察花粉萌发及生长特性。结果表明,开花当天及以后的自花和异花授粉花粉在柱头上均有较高的萌发率;自花和异花花粉管在花柱内的生长速度及停止生长的位置不同,丰水自花授粉后花粉管生长的短且慢,菊水自花花粉管生长的长且快,而异花授粉的花粉管生长最快。自花授粉后,不同花龄对花粉管生长影响表现为:开花4d前的蕾期授粉以及开花4d后的延迟授粉,花粉管生长长度显著的长。开花6d前的各种授粉组合,花粉管生长均较差。这与田间授粉坐果率的高低基本一致,即整体表现为各个花龄的授粉都以异花授粉坐果率最高,其次为菊水自花授粉,丰水自花授粉坐果率最低。另外,自花授粉中,蕾期授粉和延迟授粉(开花2d后除外)坐果率都有提高,而异花授粉中蕾期授粉和延迟授粉的坐果率却有所下降。

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.