白杨细胞质遗传的细胞学机理(Ⅱ)——质体和线粒体在生殖细胞和营养细胞中的分布与变化

Cytological Mechanism of Cytoplasmic Inheritance in Section Leuce II : Distribution and Change of Plastids and Mitochondria in Generative Cell and Vegetative Cell

应用电子显微技术,观察白杨派树种毛白杨、毛新杨、银腺杨、中国山杨花粉发育中质体和线粒体在生殖细胞、营养细胞中的分布与变化。结果表明:在小孢子第1次有丝分裂时质体由于极性分布,导致早期生殖细胞的细胞质内缺少质体,为白杨派树种质体母系遗传提供了确切的细胞学证据;线粒体在花粉发育过程中一直存在。同时,细胞学观察发现银腺杨少数质体被排除的时期相对迟缓。然而,不同发育时期营养细胞的细胞质内含有丰富的质体和线粒体。结合以往的研究工作,还对白杨质体的极性分布进行了讨论。

Distribution and change of plastlds and mitochondrla within generative cell and vegetative cell in Poplns tomentasa, P. tomentosa x P. bolleana, P. alba x P. glandulosa and P. davidiana were observed by electron microscopy. Results showed that the cytoplasm of early generative cells was free of plastids because of polar distribution of plastids in tile first microspore mitosis. This resuh provided precise cytological evidence of plastid maternal inheritance in section Leuce. The mitochondrla still existed during pollen development. Meanwhile, relatively slow elimination of some plastids was found in P. alba x P. glandulosa. However, cytoplasm of the vegetative cell during different developmental stages was rich in plasrids and mitochondria. Considering previous studies, polar distribution of plastid in section Leuce was also discussed.