金佛山方竹开花特性及花器官发育特征

Flowering Characteristics and Floral Organ Development Characteristics of Chimonobambusa utilis

以贵州省遵义市桐梓县开花的金佛山方竹竹林为研究对象,实地调查方竹的开花特性,并采用常规石蜡切片法探究金佛山方竹大小孢子发生及雌雄配子体发育过程。结果表明:金佛山方竹属于有叶开花类型,其花芽分化的时间为8月份,次年2—3月份进入开花期,小花雌雄同花,有稃片2枚(内稃和外稃),浆片3枚,雄蕊3枚,雌蕊1枚,柱头为短花柱。金佛山方竹每个花药有4个花粉囊,小孢子母细胞经过减数分裂形成4个小孢子,其排列方式为左右对称,胞质分裂为连续型,最终产生2细胞或3细胞型成熟花粉粒;金佛山方竹的花药壁绒毡层为腺质型,发育方式为单子叶型;雌蕊由两心皮卷合而成,为一室子房,有双珠被倒生胚珠,薄珠心,蓼型胚囊,大孢子四分体为一字型线形排列,位于合点端的单胞发育为具有功能的大孢子,再经3次有丝分裂发育为7胞8核成熟胚囊。

Taking the flowering forest of Chimonobambusa utilis in Zunyi City,Guizhou Province as the research object,the field investigation and flowering characteristics of flowering bamboo plants were studied,and the conventional paraffin section method was used to explore the development process of megasporogenesis,microsporogenesis and female and male gametophytes of C.utilis.C.utilis was with many leaves when it flowered.The flower bud differentiation time is in August,and blooming period starts from February to March of the following year.The floret is monoecious with palea and lemma,3 lodicules,3 stamens,1 pistil,2 stigmas with one short style.There are four pollen sacs in one anther of C.utilis,and the cytokinesis of microspore mother cells is continuous in the process of cytokinesis.The tetrad is symmetrical,and finally develops two-celled or three-celled mature pollen grains.The anther wall of C.utilis belongs to the monocotyledonous type,and the tapetum is glandular.The pistil of C.utilis is made up of two carpels,the ovary has 1 locule with double integument,and ovule is tenuinucellate.In the polygonum type embryo-sac,the megaspore tetrad is linearly arranged,and the monocyte at the chalazal end develops into a functional megaspore,and then develops into a 7-celled embryo sac with 8-nucleared via three mitotic divisions.