【摘要】 从个体发育来看,知母绒毡层具有3个明显的特点:(1)在小孢子母细胞阶段,绒毡层细胞中有丰富的细胞器,如粗糙内质网、脂体、造粉体和小泡等。粗糙内质网-脂体-小泡常常联系在一起,形成细胞器复合体。(2)在单核花粉阶段,绒毡层细胞质中出现大量小泡,它们可以融合成大泡,而且在小泡或大泡中开始沉积与脂体电子密度相似的亲锇物质,这些物质或者充满整个小泡,或者沉积在小泡周缘。此刻,也是乌氏体形成并达到高峰的阶段。(3)在成熟花粉阶段,绒毡层细胞几乎被具膜束缚的小型脂粒和巨型脂体所占据,这些亲锇物质是质体起源的,也许它们是花粉鞘的先质。更多还原

【Abstract】 From ontogeny of tapetum in Anemarrhena asphodeloides,the ultrastructural features of tapetal cells are as follows:1.The profuse rough endoplasmic reticula are often closely as- sociated with lipid bodies and vesicles,and linking each other into compound organelles.This is one of the striking features in Anemarrhena tapetal cell.2.After meiosis of the micro- spore mother cell,the tapetal cytoplasm contains a large number of vesicles,in which the ele- ctron opaque substances are accumulated.Then they fuse to form a large zone of storage ma- terial similar to lipid bodies.Before accumulation of opaque material,these vesicles in the tapetal cytoplasm are larger than those in elaioplast (see Plate Ⅱ,Fig.2).3.During stage of pollen maturation the tapetal cytoplasm becomes disorganized and the cells are almost occupied by the elaioplasts at various degree of development. On the basis of the report of Dickinson (1973),the formation of a pollen coatings of Lilium is different from that of Raphanus.The osmiophilic bodies in the former have origi- nated from membrane lamellae or membranous system of plastid,and those in the latter are formed from the plastid vescles.It is intereting to note that the mode of origin of the plastid osmiophilic bodies in Anemarrhena is rather similar to that of Raphanus than to Lilium. About the origin of the pro-Ubisch bodies in tapetal cytoplasm of Anemarrhena studies revealed that a large number of the medium electron dense bodies appear in the tapetal cyto- plasm.This is the first sign of the formation of the pro-Ubisch bodies and its character is very similar to spherosome in many respects.From many ultrasections,it can be seen that the ER profile is closely associated with the pro-Ubisch bodies.Thus we can conclude that the pro- Ubisch bodies of Anemarrhena are derived from rough endoplasmic reticulum. Although Heslop-Harrison et al.(1969) has considered that the compound Ubisch bodies do not occur in Lilium,there are prominent aggregation of Ubisch bodies in Anemarrhena, same as reported in Oxalis (Cariel,1967),Silene (Heslop-Harrison, 1963a)and Helleborus (Echlin et al.,1968). After investigation on certain angiosperm in 1972,Gupta and Nanda have reported that the peritapetal membrane belonging to tapetum of secretory type lies against the inner tang- ential wall;in the plasmodial type of tapetum,it is formed on the outer tangential wall.But in some species of Poaceae and Solanaceae,the peritapetal membrane is formed on both sides of the tapetal cells (Banerjee,1967;Reznickov & Willemse,1980).In the secretory tapetum of Anemarrhena,the peritapetal membrane,which do not comply with the conclusion of Gupta & Nanta (1972),is formed on outer tangential wall.更多还原