激光扫描共聚焦显微镜观察水稻双受精过程  

Observation on the Process of Double Fertilization in Rice Using Laser Scanning Confocal Microscopy

作　　者：代西梅[1] 黄群策[1] 李国平[1] 胡秀明[1] 秦广雍[1] 

机构地区：[1]郑州大学离子束生物工程省重点实验室,河南郑州450052

出　　处：《河南农业科学》2007年第6期25-30,共6页Journal of Henan Agricultural Sciences

基　　金：国家"863"项目(SZ-01-01-03);国家"十五"科技攻关项目(2001BA302B)

摘　　要：利用激光扫描共聚焦显微镜对水稻双受精过程进行了观察。结果表明：开花后0.5 h可见花粉粒在柱头上萌发,形成一定长度的花粉管,但仍未进入胚囊;开花后1～2 h花粉管进入胚囊,但尚未释放精细胞,此时,在卵器内有两条肌动蛋白冠的形成,肌动蛋白冠起始于助细胞的基部,1条终止于卵细胞核的位置,另一条终止于极核附近;开花后2～3 h花粉管释放精细胞,精细胞在肌动蛋白冠的作用下分别进入极核及卵细胞;开花后3～4 h,精核的染色质向卵核扩散,极核内的雄性核仁逐渐变大,最后增大至与极核的核仁差不多大小;开花后4～5 h,精核与极核完成受精作用,形成初生胚乳核,而此时在卵核内出现1个雄性核仁;开花后6 h左右,卵核核仁仍未完成与精核核仁的融合,此时初生胚乳核已分裂1～2次;开花后12 h,精核核仁与卵核核仁融合形成1个较大的核仁,至此合子形成;开花后24 h,合子有丝分裂1次,形成2个细胞的原胚,此时初生胚乳核已分裂形成8～16个游离核,绕胚囊周缘分布。水稻双受精作用属于有丝分裂前配子融合类型。The processes of double fertilization in rice were observed using laser scanning confocal microscopy. The results showed that, in 0. 5 hour after flowering, pollen with two sperm cells germinated in the stamen; in 1-2 hours,pollen tube reached to the embryo sac of ovule. Meanwhile, two actin coronas were formed in the ovule. Coronas started from the base of the synergid, one of which ended near the egg nucleus and the other near the p olar nuclei. After 2-3 hours of flowering, the sperm cells were released at the site of the degenerated synergid. When sperm cells were deposited near the base of the corona, sperm cells in the synergid subsequently migrated toward the point of fusion. In 3-4 hours after flowering, the chromatin of the sperm nucleus diffused in the egg nucleus. At the same time, the male nucleolus became larger and larger, as big as the female one. About 4-5 hours after flowering, polar nuclei were completed fertilized,forming the primary endosperm nucleus, while a small male nucleolus appeared in the egg nucleus. After 5-6 hours of flowering, the male and female nucleolus were still not fused completely, but the primary endosperm nucleushad mitosed for 1-2 times. In 12 hours after flowering, the male and female nucleolus fused and formed a large nucleolus, a symbol for the formation of zygote. In 24 hours after flowering, zygote completed its first mitosis, forming the two-cell proembryo. At the same time, the primary endosperm nucleus has divided into 8-16 free nuclei, distributing around the embryo sac. The double fertilization of rice belongs to the type of premitotic syngamy.

关 键 词：水稻 胚囊 双受精 激光扫描共聚焦显微镜 

分 类 号：S511[农业科学—作物学]