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 Impatiens exhibits some varied floral features with a dichogamous reproductive system, in which pollination biology plays a key role in speciation and adaptive evolution. China is one of the centers of Impatiens species, comprising over 300 species including a large number of endemic and sympatric distributions, but there are few data on their pollination biology. Comparative pollination biology of two Chinese endemic and sympatric species, Impatiens corchorifolia and I. polyceras, were investigated, including flowering phenology, floral features, flower visitors, behavior of pollinators, and as well as breeding systems. It was turned out as below. (1) Morphology of spur was varied in two species, which played a key role in different floral syndromes. The spurs in I. corchorifolia and I. polyceras could produced a similar nectar sugar content, (45.48 ± 2.28) % and (46.12 ± 1.48) % respectively. They could shared two pollinators, Apis cerana and Vespa. However, the short spur in I. corchorifolia produced less amount of (4.57 ± 1.43) μL nectar while the long spur in I. polyceras yielded more nectar content of (10.15 ± 3.28) μL. And then, the latter also could be pollinate by the other insects including one species of Macroglossum and two species of Bombus. (2) The behavior of the common pollinators shared in I. corchorifolia and I. polyceras were obviously distinguished by their staggered flower visits and differential sizes of flower channels for visitors with inconsistent positions of pollens carried. (3) Both species were dependent on pollinators to set fruits, which were self-incompatible, as well as cross-incompatible between two sympatric species. The results provide new data for better understanding of floral syndrome and speciation of the large genus of Impatiens.
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.
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