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为探究薄壳山核桃雄花发育及花粉粒萌发特性,以‘Mahan’为研究对象,系统观测雄蕊开花习性,从显微结构水平跟踪掌握薄壳山核桃雄花发育过程,利用扫描电子显微镜观察‘Mahan’花粉粒结构及其在雌花柱头表面的萌发特性。结果表明,3月下旬的解剖切片观察到雄花芽内有3束葇荑花序,雄蕊原基形成并分化,至4月中旬雄蕊基本形成;4月下旬雄蕊进一步分化形成小花,花药内形成4个花粉囊,花粉囊壁分为绒毡层、纤维层和中层,其内部花粉母细胞减数分裂形成四分体,至4月底绒毡层解体,四分体也解体形成4个单胞花粉粒;5月上旬花粉粒继续发育形成2-胞花粉粒,此时花粉完全成熟。人工授粉4 h后,花粉在柱头表面开始萌发;授粉12~24 h花粉普遍萌发,花粉管伸入柱头向下生长;2 d后花粉管继续伸入胚珠,柱头表面花粉管皱瘪;4 d后花粉管伸入到胚珠位置。
In order to investigate the male flower development and pollen germination characteristics in the Chinese Hickory nuthell, Mahan was used as the research object to observe the flowering habit of the stamen. The development of the male flower of Hickory nuthell was observed from the microstructure level. Pollen grain structure and its germination on female stigma surface. The results showed that there were 3 bundles of inflorescences in the male flower buds in late March. The stamens formed and differentiated to form the stamens basically in mid-April. In late April, the stamens further differentiated into small flowers and 4 in the anthers The pollen sac and pollen wall were divided into tapetum, fibrous layer and middle layer. The inner pollen mother cells meiosis formed tetrad. At the end of April, the tapetal layer disintegrated and the tetrad also disintegrated to form 4 single pollen grains In early May pollen grains continue to develop 2-cell pollen grains, pollen completely mature. After pollination for 4 h, pollen began to germinate on stigma surface; pollen germinated 12 to 24 h after pollination, and pollen tube extended downward into stigma; pollen tube continued to protrude into ovule 2 d after pollination; After the pollen tube into the ovule position.