采用光镜对舟山碎米蕨(Cheilosoria chusana)配子体发育及无配子生殖的全过程进行了观察。舟山碎米蕨孢子黄褐色,具三裂缝,极面观三角圆形,周壁表面具刺状纹饰,接种后15~20d萌发,萌发类型为书带蕨型。丝状体一般具有5-10个细胞,片状体可通过丝状体顶端或居间细胞分裂产生。播种两个月左右,在片状体的顶端或侧面产生分生组织,发育成原叶体,发育类型为水蕨型。精子器出现在不规则片状体的表面,数量较多。经多次重复培养并没有发现颈卵器的存在,原叶体通过无配子生殖发育成为孢子体。无论在丝状体、片状体还是原叶体阶段都可能产生分枝,而且只要培养条件适宜,还可发育为分枝丝状体和分枝片状体相间的配子体丛。舟山碎米蕨配子体丛比单一原叶体更能适应干旱的环境。
The gametophyte development and apogamy of the fern Cheilosoria chusana were studied using microscopy. The spores, with echinate ornamentation, are tawny, trilete, circular triangle in polar view. The spores germinate about 15 -20 d after being sowed. The spore germination pattern is the Vittaria-type. The filaments generally have 3 -5 cells. The plates form by division of the apical cell or intercalary cells of the filament. The gametophyte forms the meristematic tissue in the apical or lateral region of the plate, and grows into prothallus in about 2 months after being sowed. The development of the prothallus is the Ceratopteris-type. The antheridia appears in the irregular plates. The antheridia are numerous. The repeat cultures show that no archegonia occurs in the adult prothallus. The prothallus can produce sporophytes through apogamy. The filament branches are easily formed, whether in the stage of filaments, plates or prothallus. One spore of C. chusana can develop into caespitose gametophyte (cluster) with filaments or filamentous plates in appropriate culture conditions. It is proved that the clusters of gametophyte are in favor of adaptability to the dry environment to single prothallus.