罗汉果双受精过程的细胞学观察

罗汉果（Ｓｉｒａｉｔｉａｇｒｏｓｖｅｎｏｒｉ（Ｓｗｉｎｇｌｅ）Ｃ．Ｊｅｍｅｙ）双受精过程属有丝分裂前配子融合类型，授粉后２４～４８ｈ，花粉管进入胚囊，穿过一个助细胞，放出两个精子。雌雄核融合和雄核与次生核融合同时发生在授粉后６２～７２，雄核与次生核融合速度快于配子融合，７２ｈ后即可见到初生胚乳核分裂。合子中的雌雄核仁在授粉后第５～６ｄ融合，授粉后８～９ｄ合成分裂形成二细胞胚。在双受精过程中，多次观察到有多条花粉管进入胚囊和多精入极核现象。原胚期有附加花粉管从珠孔进入。

CYTOLOGICAL OBSERVATION OF THE DOUBLE FERTILIZATION IN SIRAITIA GROSVENORI

The double fertilization in Siraitia grosvenori (Swingle) C. Jeffrey is the type of the premitotic syngamy. In 20 to 48 hours after pollination, the pollen tubes entered the embryo sac,cut across a synergid, then released two sperms. In 62 to 72 hours after pollination, the female nucleus fused with the male nucleus and the male nucleus fused with the secondary nucleus. The fussion between the male nucleus and the secondary nucleus was faster than the fussion betwiin the female nucleus and the male nucleus. In 72 hours after pollination, the primary endosperm nucleus divided. In 5 to 6 days after POllination, the female hucleolus fused with the male nucleolus in the zygote. In 6 to 9 days after pollination, the zygote divided to form two-celled embryo. During the double fertilization, many pollen nucleus. In the proembryonal stage, the additioinal pollen tubes entered from micropyle.