黄瓜雌花发育过程中柱头的腺特征

利用透射电镜技术研究了黄瓜(Cucumis sativus L.)雌花柱头发育过程中传递组织、分泌组织和乳突细胞的超微结构.在整个发育过程中,乳突细胞和分泌组织细胞的细胞质内密布很多管状及槽库膨大的内质网,产生很多分泌囊泡;在成熟柱头的传递组织和分泌组织细胞间观察到大量的胞间连丝;乳突细胞和分泌细胞高度液泡化,质膜内折;在柱头发育过程中分泌组织细胞的核周腔扩大形成裂瓣状核,到柱头成熟阶段裂瓣状核更加明显.进一步的研究显示,在成熟柱头的不同组织细胞中,ATPase的活性呈现在质膜和液泡膜上,随着柱头的发育,PM-H -ATPase的比活性明显增强.结果表明,黄瓜雌花柱头的腺特征随发育进程而趋于显著.

Glandular Characteristics of the Stigma During the Development of Cucumis sativus Female Flowers

The stigma initiation and development of Cucumis sativus L. female flower was studied using electron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud was about 1 mm in length. After the pinnate structure of the stigma appeared, three regions indicating the papillae, the transmitting tissue and the secretory tissue were observed. The pinnate stigma was characterized as a partition structure for naming immature and mature stigma in the following investigation. The ultrastructure of various tissue cells of the stigma during the development was observed using transmission electron microscopy. Throughout the whole developmental process the cytoplasm of papillae and secretory tissue cells was filled with many endoplasmic reticula (ER). Most of the ER was tube-like and rough with enlarged cisterna from which many vesicles were produced. In the mature stigma, numbers of plasmodesmata were found between the secretory and the transmitting tissue cells. The papillae and secretory tissue cells are highly vacuolated and the plasmalemma was invaginated or exvaginated. The nuclear envelope of secretory tissue cells was enlarged, which led to the formation of plurivalvis nucleus during stigma development. Apparently, nuclear envelope became more strongly lamellate at mature stage. In different tissue cells of mature stigma, ATPase activity was localized along the plasmalemma and vacuole membrane. The PM-H⁺-ATPase specific activity increased during stigma development. Our results revealed the glandular characteristics of the developing stigma of cucumber female flowers.