同源四倍体矮脚黄白菜与甘蓝型油菜杂交的胚胎学研究

STUDY ON THE EMBRYOLOGY OF CROSSES BETWEEN AUTOTETRAPLOID AIJIAOHUANG (BRASSICA CHINENSIS L.) AND BRASSICA NAPUS

将甘蓝型油菜的花粉授在同源四倍体小白菜的柱头上时，少数柱头乳突细胞出现胼胝质沉积，杂交的受精过程及胚和胚乳的早期发育基本正常。但与四倍体白菜自交相比，进入花柱的花粉管较少，胚和胚乳的发育进程较缓慢。由于杂种胚发育缓慢，在胚乳细胞发生退化时，多数杂种胚处于晚球形、心形或鱼雷形阶段。随着胚乳细胞的消失，杂种胚停止发育并最终解体。授粉后３０ｄ，杂种胚珠大多解体，仅有少数胚珠能发育为成熟可育的种子。因此，在同源四倍体小白菜留种时，必须与甘蓝型油菜进行一定程度的隔离。

After pollens of autotetraploid Aijiaohuang were pollinated on stimas of B. napus, some papillae cells produced callose, and thus pollen tubes of B. napus into style were less than those of selfed Aijiaohuang. Fertilization, early embryonic and endosperm devlopment were generally normal. However, the development of hybrid embryos and endosperm fell behind that of selfpollination of Aijiaohuang. Because of slow development of hybrid embryo, embryos were still globeshaped, heartshaped or torpedoshaped at degeneration of endosperm cells. With the disappearance of endosperm ,hybrid embryos ceased to develop and disintegrate at last. Thirty days after pollination, most of the hybrid ovules disintegrated, but a few hybrid ovules can develop into mature seeds. Therefore, autotetraploid Aijiaohuang needs to be kept away from B. napus when the seeds are reproduced.