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MARKUS RUHSAM RAFAEL GOVAERTS AARON P. DAVIS fls 《Botanical journal of the Linnean Society. Linnean Society of London》2008,157(1):115-124
During the preparation of a World Rubiaceae Checklist , numerous unplaced taxa were encountered, including illegitimate and invalid names, and species for which generic placement is uncertain. In this contribution, 35 new combinations and 20 new names are proposed, and the names of three taxa are validated. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 115–124. 相似文献
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Zhonglai Luo Tingting Duan Shuai Yuan Shi Chen Xiufeng Bai Dianxiang Zhang 《植物学报(英文版)》2015,57(10):859-870
Reproductive isolation de fi nes the biological species concept and plays a key role in the formation and maintenance of species. The relative contributions of different isolating stages has been suggested to be closely associated with phylogenetic relatedness. Few studies have focused on the relative contributions of pre- versus postzygotic mechanisms, and even fewer have been conducted under strict phylogenetic frameworks. Pre- and post-zygotic reproductive isolation stages have been investigated in the sister species Mussaenda kwangtungensis and M. pubescens var. alba. The two species have partly overlapping distribution ranges and fl owering times, while the principal pollinators differed strikingly for them, demonstrating strong pre-zygotic isolations. Natural hybrids were detected by simple sequence repeat markers and their maternal parents were identi fi ed based on chloroplast gene sequences. Five out of 81 individuals were suggested to be hybrids that fall into the categories F2, BC1, and BC2 by theNew Hybrids analysis. Interspeci fi c crossings resulted in signi fi cantly reduced fruit set and seed germination rates.Phylogenetic analysis revealed short Kimura-2-parameter distance between M. kwangtungensis and M. pubescens var.alba. These fi ndings strongly supported the hypothesis that for species with a closer phylogenetic relationship, prezygotic isolation plays an important part in limiting gene exchange in sympatric areas. 相似文献
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Reproductive isolation is a fundamental requirement for speciation and includes several sequential stages.Few studies have determined the relative contributions of pre-and post-zygotic reproductive isolation in plants,especially between relative species with clear differentiation in flower form.To investigate the mechanisms responsible for reproductive isolation in sympatric Mussaenda pubescens var.alba and Mussaenda shikokiana(Rubiaceae)in Guangxi Province,China,we made observations of flowering phenology,patterns of insect visitation,and conducted pollination experiments,including artificial hybridization.The two species had overlapping flowering times and were pollinated by overlapping pollinators;however,their relative importance differed significantly with M.pubescens visited more commonly by bees and M.shikokiana more frequently by butterflies.Using vegetative and floral characters and molecular evidence based on nuclear ribosomal internal and external transcribed spacer regions we detected seven naturally occurring hybrids among a sample of approximately 125 individuals.Hybrids werecharacterized by morphologies that most closely resembled their maternal parents based on chloroplast evidence.Studies of artificially synthesized and natural hybrids demonstrated that hybrid seed had very low germination rates and naturally occurring hybrids exhibited pollen sterility.Post-zygotic reproductive isolating mechanisms play a primary role in limiting gene exchange between co-occurring species and maintaining species integrity in areas of sympatry. 相似文献
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Mussaenda yunnanensis, a new dioecious species of Rubiaceae from Yunnan Province, China, is described and illustrated. The new species can be recognized by its slender stem, congested‐cymose inflorescences and long corolla tubes. Differences between M. yunnanensis and two morphologically similar species (M. pubescens and M. antiloga) are presented. We also provide a key to all dioecious species of Mussaenda in China. The delimitation of the new species is further supported by molecular phylogenetic analyses based on eight plastid loci. 相似文献
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Exploration of Phytoconstituents from Mussaenda roxburghii and Studies of Their Antibiofilm Effect
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Arpita Sarkar Antu Das Padmani Sandhu Biswanath Dinda Yusuf Akhter Surajit Bhattacharjee Utpal Ch. De 《化学与生物多样性》2017,14(10)
In the context of ethno botanical importance with no phytochemical investigations, Mussaenda roxburghii have been investigated to explore it's phytoconstituents and studies of their antibiofilm activity. Four compounds have been isolated from the aerial parts of this plant and were characterized as 2α,3β,19α,23‐tetrahydroxyurs‐12‐en‐28‐oic acid ( 1 ), β‐sitosterol glucoside ( 4 ), lupeol palmitate ( 5 ), and myoinositol ( 6 ). All these compounds were tested for antibacterial and antibiofilm activity against Pseudomonas aeruginosa. Compound 1 exhibited three times more antibiofilm activity with minimum inhibitory concentration (MIC) at 0.74 mm compared to that of streptomycin. Molecular docking studies exhibited a very high binding affinity of 1 with P. aeruginosa quorum sensing proteins and motility associated proteins viz. LasR and PilB, PilY1, PilT, respectively. Compound 1 was also found to be non‐cytotoxic against sheep RBC and murine peritoneal macrophages at selected sub‐MIC doses. 相似文献
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Mussaenda lancipetala X. F. Deng & D. X. Zhang, a new species of Rubiaceae from Yunnan Province, Southwestern China, is described and illustrated. The new species is characterized by its reverse herkogamous sexual system, its ovate-lanceolate corolla lobes with caudate apex, and corolla tube covered with sparse farinose pubescence, by which it is clearly distinguished from other species of Mussaenda. 相似文献
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澄清了中国产玉叶金花属Mussaenda 2种1变型的分类学位置, 分别将胀管玉叶金花M. inflata Hsue &; H. Wu、异形玉叶金花M. anomala Li和灵仙玉叶金花M. pubescens Ait. f. forma clematidiflora Chun ex Hsue &; H. Wu作为粗毛玉叶金花M. hirsutula Miq.、大叶白纸扇M. esquirolii Lévl.和玉叶金花M. pubescens Ait. f.的新异名处理。 相似文献