海岛棉半配生殖品系有性过程的胚胎学观察

Embryological Investigation of Sexual Process of Semigametic Line in Gossypium barbadense L.

半配生殖品系VSg自交或以VSg作母本与海岛棉标准系3-79杂交,花粉能在柱头上萌发,花粉管能在花柱组织中生长并能进入胚珠到达胚囊。精核与极核融合、初生胚乳核分裂,以及胚乳游离核形成均表现正常,但精卵融合不同于3-79。突出表现在一部分胚囊中,进入卵细胞的精核迟迟不与卵核融合,未融合的二核“合子”经过一段比3-79稍长些的“休眠期”后,各自独立分裂,形成各种类型的嵌合胚。

When Semigametic line VSg was selfed or crossed as female parent with Sea Island Cotton standard line 3-79, the pollens can germinate on the stigma, and the pollen tubes can penetrate into the style tissue, enter ovule and finally go into the embryo sac. The sperm nucleus fuses with the two polar nuclei forming primary endosperm nuclei, which divide and form free endosperm nuclei normally. However, the sperm nucleus entering into egg cell doesn't fuse with the egg nucleus lingeringly in some embryo sac. The unfused binuclear ((?) + (?) )'zygote'has a longer 'quiescent stage'than that of 3-79. Afterwards, it divides independently and produces different kinds of chimeras.