糜子双受精过程的细胞学观察

糜子(Panicum miliaceum L.)受精的全过程在开花后3小时内完成。开花后20分钟,花粉管到达珠孔,30分钟进入胚囊并释放精子;雌、雄性核融合发生在开花后30分钟至3小时。精核与卵核和极核融合的过程基本相同,但总是先完成与极核的融合。开花后2小时,初生胚乳核形成,随后立即分裂。开花后3小时,合子形成,此时胚乳含两个游离核。开花后8—10小时,合子进入分裂期。合子的休眠期约5—7小时。受精作用属于有丝分裂前配子融合的类型。

CYTOLOGICAL STUDIES OF THE DOUBLE FERTILIZATION IN PANICUM MILIACEUM L.

Detailed studies on the double fertilization process and its duration of different stages in Panicum miliaceum L. were conducted. The main results are summarized as follows: The whole process of fertilization completes in 3 h after anthesis. The pollen tube reaches the mi- cropyle of ovule in 20 min and enters the embryo sac and releases sperms 30 min after anthe- sis. The fusion of female and male nuclei occurs in a period of 30 min to 3 h after anthesis. The process of syngamy is almost the same as that of triple fusion, however, triple fusion ends always earlier. Primary endosperm nucleus forms 2 h after anthesis, and then divides. Zygots forms 3 h after anthesis when endosperm contains two free nuclei.The first mitotic division of zygote takes place 8-10 h after anthesis. Zygote has a dormancy period of 5--7 h. The double fertilization is a type of premitotic syngamy.