红盖鳞毛蕨孢子囊早期发育与质体分化的研究

Development of Sporangium at the Early Stage and Plastid Differentiation in Dryopteris erythrosora

利用光学显微镜和透射电子显微镜观察了红盖鳞毛蕨(Dryopteris erythrosora(Eaton)O.Ktze.)孢子囊的发育及在此期间质体的分化过程。研究表明:(1)红盖鳞毛蕨孢子囊的发育类型属于薄囊蕨型;(2)绒毡层为混合型,即内层绒毡层为原生质团型,外层绒毡层为腺质型;(3)孢子囊原始细胞中的质体通过3条路径分化,其一,原始细胞中含淀粉粒的质体通过分裂分配到下方细胞,继而进入孢子囊柄;其二,原始细胞分裂产生的新生质体被分配到上方细胞,进而被分配到除顶细胞外的原基细胞中,顶细胞将含淀粉粒的质体通过分裂分配到外套层原始细胞中;其三,顶细胞也将具淀粉粒的质体通过分裂分配到内部细胞,使分裂产生的孢原细胞和绒毡层原始细胞具新生质体;造孢细胞和孢子母细胞的质体具淀粉粒,孢子母细胞还具油体,新生孢子中具造粉体和油体;两层绒毡层具新生质体,随着退化外层绒毡层出现造粉体,内层绒毡层出现油体;(4)红盖鳞毛蕨与少数被子植物小孢子发育阶段质体分化模式类似,由前质体分化为造粉体再到油体。研究结果为蕨类植物质体在孢子囊发育过程不同组织细胞中的差异分化提供了新观察资料,为蕨类植物发育生物学和系统演化研究提供科学依据。

Development of sporangium at the early stage and the differentiation of plastids in Dryopteris erythrosora were studied using light microscopy and transmission electron microscopy. Results showed that：（ 1） The development of Dryopteris erythrosora sporangia belonged to the leptosporangiate type.（ 2） The tapetum was mixed type,with an inner amoeboid tapetum layer,and outer parietal tapetum layer.（ 3） The plastids in the initial cell of the sporangium differentiated in three ways. First,the plastids containing starch grains in the initial cells were allocated into the lower cells and then the cells of the sporangium stalk.Second,the newly formed plastids in the initial sporangium cells were allocated into the upper cells and then into primordium cells,except the apical cells. The plastids with starch grains in the apical cells were allocated into the initial cells of the sporangium wall. Third,the plastidswith starch grains in the apical cells were also allocated into the internal cells of the young sporangium. The internal cell divided periclinally and formed sporogenous cells and tapetal initial cells,both of which contained newly produced plastids. The sporogenous cells and the spore mother cells contained the plastids with starch grains. The spore mother cells also contained oil bodies. The young spores possessed amyloplasts and oil bodies. Both the inner and outer tapetum cells possessed newly formed plastids. With the degeneration of the tapetum,the amyloplasts occurred in the outer layer of the tapetum cells and oil bodies occurred in the inner layer of the tapetum cells.（ 4） The differentiation of the plastids in Dryopteris erythrosora was similar to that of microspore development in some angiosperms.The present investigation provides new cytological features for the differentiation of plastids in different tissues during sporangium development. It also lays a foundation for studying the developmental biology and phylogeny of ferns.