Subjects: Biology >> Botany >> Applied botany submitted time 2023-10-22 Cooperative journals: 《广西植物》
Abstract： The taxonomy of Paphiopedilum Pfitz. has been disputed and needed more data for clarification. Floral morphology and anther development in P. purpuratum were observed using microscope and paraffin section to provide a better understanding of the systematics of Paphiopedilum, as well as those of Cypripedioideae. The results were as follows: (1) It was supported that P. purpuratum should be placed in Paph. subgenus Paphiopedilum Sect. Barbata by some floral features, including a single flower, sepal white with veins, petal spotted with blackish-maroon, pouch of a lip auriculate on both sides, and a staminode lunate. (2) At the early stage, anther primordium developed into a pair of laterally juxtaposed thecae. An incomplete sterile septa was differentiated in the center of each theca, giving rise to two arc-shaped microsporangia. When anther split, the sterile septum was discomposed and degenerated resulting in a mass of sticky pollens from two pollen sacs were fused into a unit. (3) The developed anther wall consisted of an epidermis, an endothecium, a middle layer, and a tapetum, conforming to the monocotyledonous type. Both tapetum and inner tapetum cells contained 2 nuclei. (4) Microspore mother cells underwent a simultaneous cytokinesis resulting in microspore tetrads with varied arrangements of tetrahedral, isobilateral, and decussate types. (5) Microspores produced 2-celled pollens via mitosis, which could be retained in pollen tetrads or released as monad. Based on the data available, some key features were selected for taxonomy and conservation biology of Paphiopedilum in Cypripedioideae, including the differentiation of sterile septum, the monocotyledonous type of anther wall, the binucleated tapetum, simultaneous cytokinsis, the sticky pollens and so on in Orchidaceae.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： The genus Habenaria exhibits a highly diversity in floral morphology and has complex taxonomy problems. In order to identify key taxonomic features of this genus, floral structure and column ultrastructure of Habenaria dentata and Habenaria glaucifolia were investigated using the stereo microscope and scanning electronic microscope (SEM). The results were as follows: (1) The two Habenaria species exhibited significant differences in floral structures, specifically in terms of the presence or absence of lateral petal lobes, the morphology of the 3-lobed lip, and the ratio of the length between the spur and the ovary. (2) The column ultramicro characteristics of two Habenaria species were significantly varied, containing morphology of staminode, anther chamber exine cell, “anther-canal” exine cell, elongated stigma and papilla at the junction with style. (3) Exine sculptures of massula were distinguished in two species, the reticulate type in Habenaria dentata, and the baculate → reticulate type in Habenaria glaucifolia. This study investigates the taxonomic implications of floral features and column ultrastructure in Habenaria species, with a specific focus on the examination of Habenaria glaucifolia. Through the analysis of available data, certain selected features were identified as potentially valuable for species delimitation, including the presence or absence of lateral petal lobes, variations in spur morphology, the length ratio of the spur to the ovary, and the types of pollen exine sculpture. Additionally, the floral structure and column ultrastructure of Habenaria glaucifolia were supplemented and thoroughly analyzed based on reported data. Notably, it was not confirmed that Habenaria glaucifolia should not be treated as an independent genus from Habenaria. The results of this study provide novel insights and serve as a valuable reference for the classification of Habenaria species distributed in Asia.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-18 Cooperative journals: 《广西植物》
Abstract： In order to provide new data for clarification of the generic relationship in Hypoxidacae, morphology, ultrastructure, and anatomy of leaf from five species in Hypoxidaceae were investigated using microscope, scanning electronic microscope (SEM), and paraffin section. It turned out that there were five points of views as below ： (1) Three types of leaf shapes were characterized, including small-even, middle-wave, and large-plicate. (2) Trichomes were single-celled and uniseriate, and grouped into pilose, strigose, and stellate. (3) Shapes of leaf epidermal cells were hexagon and pentagon, while stomata was paracytic and elliptic with a correlation between size and density. (4) Sculptures of wax in epidermis was classified into smooth, granular, scales, and crust. (5) Leaf anatomy revealed two types of vascular bundles and relevence between thickness of epidermis and size of epidermal cells. Based on comparative morphology and anatomy of leaf, it is suggested that complex of some characters would be helpful for understanding of generic relationships in Hypoxis L., Curculigo Gaertn. and Molineria Colla., while other characteristics for species identifications.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-11-27 Cooperative journals: 《广西植物》
Abstract：近年来的分子系统学把狭义萝藦科和狭义夹竹桃科合并为广义夹竹桃科，包括5 个亚科和25 个族，但亚科和族间的亲缘关系较为复杂，亟待多学科证据澄清。本文利用常规石蜡切片技术观察了马利筋亚科南山藤属中的中国特有植物苦绳（Dregea sinensis Hemsl. var. Sinensis）的大小孢子发生和雌雄配子体发育，结合已有资料比较了5 个亚科的胚胎学特征，结果表明：（1）苦绳的花药由一对侧生并列药室组成，每个药室有一个花粉团；（2）花药壁有6 层，由外至内分别为表皮、2 层药室内壁、中层和2层绒毡层，花药壁发育模式属于多层型；（3）单核绒毡层细胞排成2 列，为腺质型；在小孢子四分体形成时期，药室内壁发生明显纤维状加厚；花药成熟时，位于药室远轴最外侧处的花药壁发生断裂，准备散粉；（4）小孢子母细胞减数分裂胞质分裂为连续型，小孢子四分体排列方式为左右对称型；成熟花粉粒为3-细胞型，排列紧密，形成花粉团；（5）雌蕊含有两枚离生心皮，具边缘胎座，胚珠倒生，单珠被，薄珠心，蓼型胚囊。苦绳的大小孢子发生和雌雄配子体的发育特征补充了南山藤属的胚胎学资料。同时，胚胎学特征在5 个亚科间的区别和联系，支持广义夹竹桃科的确立。
Subjects: Biology >> Botany >> Applied botany submitted time 2020-01-12 Cooperative journals: 《广西植物》
Abstract：利用石蜡切片技术观察了兰科单型属竹叶兰属的花粉团发育过程，包括花形态解剖特征、8个花粉团的形成机制、花药壁发育模式、小孢子发生及雄配子体发育等特征，为该属复杂的系统亲缘关系提供胚胎学证据，结果如下。成熟花药有两个药室，每个药室有4个一簇金色的花粉团，被白色花药帽。早期花药原基分化出的一对并列侧生药室，每个药室中央小孢子囊分化出一对纵横交错的不育隔膜组织将其分割为4个次生小孢子囊，最后发育为4个花粉团。花药成熟时，由于每个药室内的花粉团间的隔膜组织发生不彻底降解，导致4个花粉团在花药开裂处粘合成一簇。发育完好的花药壁共有6 ~ 7层，由外到内为表皮、3 ~ 4层药室内壁、中层和双核绒毡层，符合多层型花药壁的发育模式。花药成熟时，表皮退化，纤维性加厚发生在3 ~ 4层药室内壁，中层和绒毡层彻底降解。小孢子母细胞通过同时型胞质分裂产生了正四面体型、左右对称、十字交叉型排列的小孢子四分体。小孢子四分体继续保持在同一胼胝质内完成了雄配子体发育，形成了2 - 细胞型的四合花粉。四合花粉两两或松散或紧密排列，构成了粉质花粉团。在前人的研究基础上，本文证实、补充并分析了竹叶兰属的花粉团发育特征，为该属的亲缘关系提供了胚胎学证据。
Subjects: Biology >> Botany >> Applied botany submitted time 2019-02-25 Cooperative journals: 《广西植物》
Abstract：在夏枯草转录组测序的基础上设计特异引物，采用逆转录PCR技术获得该基因的全长核苷酸序列，并进行生物信息学分析，采用qRT-PCR法分析PvDXS在夏枯草不同组织及不同外源性物质诱导下的表达量。克隆得到的PvDXS基因开放阅读框2181 bp，编码726个氨基酸，理论分子量为78 040.47 D，等电点为6.75,PvDXS 蛋白具有Transketolase_C 结构域和Transket_pyr 结构域，系统进化树结果表明，PvDXS 蛋白与丹参、长春花的DXS（SmDXS2、CrDXS2）亲缘关系较近，推测PvDXS 属于第II 类DXS 蛋白。qRT-PCR 分析表明，PvDXS 基因在叶中表达量高于果穗及茎。对果穗施加7种外源性物质处理24 h后，GA3处理组该基因表达量升高，其它6种外源性物质处理后表达量均降低，其中CaCl2、SNP、SA处理后该基因的表达量显著降低。PvDXS基因在不同组织中表达量差异较大，且受外源物质诱导表达，该研究结果为进一步研究PvDXR基因对夏枯草萜类成分合成途径中的功能及表达调控奠定基础
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