| 翼萼蔓属系统位置的研究 |
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| 引用本文： | 陈世龙,何廷农,洪德元.翼萼蔓属系统位置的研究[J].中国科学院研究生院学报,1998,36(1):58-68. |
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| 作者姓名： | 陈世龙 何廷农 洪德元 |
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| 摘 要： | 对翼萼蔓属进行了外部形态、花部解剖学、大小孢子发生和雌雄配子体发育、花粉形态和染色体
的研究，并以此为据，讨论了该属的分类等级和系统位置。翼萼蔓属的花具花冠腺体。花萼筒具16条
维管束，花冠筒具12条维管束，二者的维管束是独立发生的。每心皮具1条背维管束和2条腹维管束。
雄蕊先熟。花药四室；药壁发育为双子叶型；绒毡层异型起源，细胞具双核，属腺质型绒毡层；一层中层
细胞；药壁表皮层宿存，细胞膨大，细胞壁纤维状加厚；药室内壁部分纤维状加厚。小孢子母细胞减数分
裂的胞质分裂为同时型；成熟花粉为3-细胞型。子房为2心皮，1室，超侧膜胎座；胚珠25～40列，倒生
胚珠，腹维管束靠近腹缝线。薄珠心，单珠被。大孢子母细胞减数分裂形成的4个大孢子呈直线式排
列，其中合点端的大孢子具功能。胚囊发育为蓼型。极核在受精前融合为次生核，反足细胞3个，具反
足吸器。胚乳发育为核型。花粉球形，极轴长约32.8μm，赤道轴长约34.2μm，外壁纹饰为网状纹
饰。体细胞染色体数为2n=26，染色体基数为x＝13，核型公式为2n＝26＝18m＋4sm+2st＋2t，属
2A型。比较翼萼蔓属、蔓龙胆属和扁蕾属的外部形态、花部解剖学、胚胎学、花粉形态和染色体特征，表
明翼萼蔓属和扁蕾属可能具较近的亲缘关系，起源于一个较早的共同祖先。在分类等级上，把翼萼蔓属作为一独立属处理较为合适。
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| 关 键 词： | 翼萼蔓属 系统位置 |
On Systematic Position of Pterygocalyx (Gentianaceae) |
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| CHEN Shi-Long,HO Ting-Nong,HONG De-Yuan.On Systematic Position of Pterygocalyx (Gentianaceae)[J].Journal of the Graduate School of the Chinese Academy of Sciences,1998,36(1):58-68. |
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| Authors: | CHEN Shi-Long HO Ting-Nong HONG De-Yuan |
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| Abstract: | The gross morphology, floral anatomy, embryology, pollen and karyotypes of
Pterygocalyx volubilis were studied. The results are used to reevaluate the taxonomic status
of the monotypic genus Pterygocalyx. Pterygocalyx volubilis has epipetalous glands. There
are 16 bundles in calyx tube and 12 bundles in corolla tube, the calyx and corolla bundles are
different in origin. Each carpel has one dorsal and two ventral bundles. Flowers are protan-
drous. The anther is 4-sporangiate. The development of anther walls conforms to the di-
cotylendonous type . The tapetum is of glandular type, dual origin, and binucleate cells at the
late stage. The epidermis and part of endothecium persist; epidermisis fibrous-thickened.
Cytokinesis in the microsporocyte meiosis is simultaneous, and tetrads are tetrahedral. Pollen
grains shed at the 3-celled condition. The ovary is bicarpellate and unilocular. The placenta-
tion is of superficial placentae with 25～40 series of ovules. The ovule is unitegmic, tenuinu-
cellar and anatropous. The embryo sac originates from a single archesporial cell. The chalazal
megaspore in linear tetrad becomes the functional one. The development of embryo sac is of
the Polygonum type. Before fertilization, two polar nuclei fuse into a secondary nucleus.
Three antipodals persist, become much enlarged, and function as haustorium. The develop-
ment of the endosperm is of the Nuclear type. Pollen grains of Pterygocalyx are spheroidal,
32.8×34.2 μm in size with exine ornamentation being reticulate. The chromosome number
of Pterygocalyx is 2n＝26, with the basic number x＝13. The karyotype is formulated as 2n
=26＝8m+4sm+2st+2t, belonging to “2A” type in Stebbins'classification. The genus
Pterygocalyx is closely related to Gentianopsis . It is better to treat Pterygocalyx as an in-dependent genus. |
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| Keywords: | Pterygocalyx Systematic position |
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