The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. Af...The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. After the pinnate structure of the stigma appeared, three regions indicating thepapillae, the transmitting tissue and the secretory tissue were observed. The pinnate stigma wascharacterized 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 usingtransmission electron microscopy. Throughout the whole developmental process the cytoplasm of papillaeand secretory tissue cells was filled with many endoplasmic reticula (ER). Most of the ER was tube-like andrough with enlarged cisterna from which many vesicles were produced. |n the mature stigma, numbers ofplasmodesmata were found between the secretory and the transmitting tissue cells. The papillae andsecretory tissue cells are highly vacuolated and the plasmalemma was invaginated or exvaginated. Thenuclear envelope of secretory tissue cells was enlarged, which led to the formation of plurivalvis nucleusduring 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 andvacuole membrane. The PM-H*-ATPase specific activity increased during stigma deve{opment. Ourresults revealed the glandular characteristics of the developing stigma of cucumber female flowers.展开更多
文摘The stigma initiation and development of Cucumis sativus L female flower was studied usingelectron microscopy. The differentiation of stigmatic cells could be recognized when the floral bud wasabout 1 mm in length. After the pinnate structure of the stigma appeared, three regions indicating thepapillae, the transmitting tissue and the secretory tissue were observed. The pinnate stigma wascharacterized 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 usingtransmission electron microscopy. Throughout the whole developmental process the cytoplasm of papillaeand secretory tissue cells was filled with many endoplasmic reticula (ER). Most of the ER was tube-like andrough with enlarged cisterna from which many vesicles were produced. |n the mature stigma, numbers ofplasmodesmata were found between the secretory and the transmitting tissue cells. The papillae andsecretory tissue cells are highly vacuolated and the plasmalemma was invaginated or exvaginated. Thenuclear envelope of secretory tissue cells was enlarged, which led to the formation of plurivalvis nucleusduring 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 andvacuole membrane. The PM-H*-ATPase specific activity increased during stigma deve{opment. Ourresults revealed the glandular characteristics of the developing stigma of cucumber female flowers.
