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1.
eterachopsis was proposed by the senior author as an independent genus of the family Aspleniaceae in 1940 with 2 species. Since then much study on its morphology, anatomy, gametophyte and palynology has been carried out by Nayar, Bir, Chandra & Nayar and Chang et al., and they are of the opinion that the genus like Ceterach, is a comparatively primitive element in the family Aspleniaceae. The queer zigzag patern of cutting of lanceolate fronds appears extraordinary in the family Aspleniaceae, and also suggests its antiquity in evolution. So far only 3 species (C. dalhousiae, C. paucivenosa and C. magnifica) are recognized, the former from W. Himalayas, also known from Africa, while the latter two from W. S. China (Yunnan). However, in the past forty years the Chinese botanists have discovered 2 more species as new in N. W. Yunnan, thus bringing the total known species of the genus up to 5. The present paper is a brief summary on the genus Ceterachopsis, which will be published in detail in the Flora Sinica vol. 4. Pteridologists are also divided in their views regarding the generic status of Ceterachopsis with 5 well-defined species in Yunnan and the East Himalayas. We prefer to mintain it as a genus separate from Asplenium on account of its distinct morphological features. It is to be hoped that more species may come to light in the mountainsin N. W. Yunnan through further exploration now under way.  相似文献   

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As part of our search for new bioactive saponins from Cameroonian medicinal plants, two new oleanane‐type saponins, named gummiferaosides D and E ( 1 and 2 ), along with one known saponin, julibroside J8 ( 3 ), were isolated from the roots of Albizia gummifera. Their structures were established on the basis of extensive 1D‐ and 2D‐NMR (1H‐ and 13C‐NMR, DEPT, COSY, TOCSY, NOESY, HSQC, HSQC‐TOCSY, and HMBC) and HR‐ESI‐MS studies, and by chemical evidence. The apoptotic effect of saponins 1  –  3 was evaluated on the A431 human epidermoid cancer cell. Flow cytometric analyses showed that saponins 1  –  3 induced apoptosis of human epidermoid cancer cell (A431) in a dose‐dependent manner.  相似文献   

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Summary In vitro conditions are defined for starting and maintaining callus and suspension, cells from two cotton (Gossypium hirsitum L.) varieties, Im 216 and Acala 44, which are resistant and susceptible, respectively, to the bacterial pathogenXanthomonas malvacearum (E. F. Sm.) Dows. A light, friable callus was easily obtained and has been maintained for over 4 years. Whether stems or leaves, the explant source for callus initiation made no difference for growth of callus tissue. Acala 44 callus had a fresh-weight doubling time of 4 to 5 days, and Im 216 callus had a fresh-weight doubling time of 4 to 9 days; however, in suspension culture the fresh-weight doubling times for Im 216 and Acala 44 were 6 days. The pH of the suspension medium dropped to 4.7 during the exponential growth phase and rose to 5.4 at the stationary phase. Attempts to induce root and shoot initiation from these callus cells were unsuccessful; however, greening of the callus tissue did occur. Schenk and Hildebrandt medium was used for both callus and suspension cultures. Inoculation of Im 216 and Acala 44 callus tissues with two races ofX. malvacearum resulted in a resistant and susceptible response, respectively. This research was supported in part by C. S. R. S. Grant 315-16-96 and the Agricultural Experiment Station of Oklahoma State University.  相似文献   

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《Journal of bryology》2013,35(4):805-806
Abstract

Four small moss families found in Malawi are reviewed, and keys are provided to all taxa known in Malawi (and usually to all known in Africa). Regmatodontaceae is shown to contain only one species in Africa, but both known species are keyed. Rhachitheciaceae, contains three genera in Africa (which are keyed), only one of which occurs in Malawi, and for this genus a key is provided for all three African species. Rhacocarpaceae contains only two species in Africa, which are keyed, only one of which is known from Malawi. Rhizogoniaceae contains two genera and three species in Africa.  相似文献   

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The distribution of 14C-labelled assimilates in dwarf beansinfected on one unifoliate with Xanthomonas phaseoli or systemicallyinfected with the pathogen was compared with the distributionin plants subjected to water stress. Unifoliates on systemically-infectedand water-stressed plants retained a much greater proportionof assimilated 14CO2 than equivalent leaves on healthy plants,but unifoliates directly inoculated with X. phaseoli (localinfection) retained only a slightly larger proportion than controlplants. Local infection had little influence on the distribution ofexported radiocarbon but systemic infection produced markedeffects and there were similar changes in water-stressed plants.These changes seem to be related mainly to changes in growthpatterns, particularly to the reduced development of trifoliateleaves. The main causes of the altered assimilate distributionappear to be modified source-sink relationships, but the natureof the vascular system of dwarf bean and interference with vascularfunction by X. phaseoli seem to be more significant factorsthan in other diseases where assimilate distribution has beenstudied.  相似文献   

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Lindera glauca (Sieb. et Zucc.) Blume (Lauraceae) has been used to treat rheumatic arthritis, stroke, and cardiac pain. Phytochemical investigation of twigs of L. glauca (Sieb. et Zucc.) Blume resulted in the isolation and identification of a new cerebroside, glaucerebroside (1). The structure of 1 was elucidated by a combination of extensive spectroscopic analyses, including extensive 2D NMR, HR-MS, chemical reactions, and LC/MS analysis. Compound 1 is a relatively rare cerebroside with l-threo-configuration of the sphingosine part. This is the second example of identification of a cerebroside from the family Lauraceae. Compound 1 significantly inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV-2 cells, with an IC50 value of 23.84 μM without inducing cell toxicity. This study suggests that glaucerebroside (1) can be an excellent candidate for development of novel anti-neuroinflammatory agents.  相似文献   

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Rhizomes developed in vitro on shoots of Costus speciosus (Koen.) Sm. which were initiated from zygotic embryos. The effect of different hormonal and nutritional additions to Schenk and Hildebrandt' s (SH) basal nutrient medium on rhizome development was studied. Rhizomes developed on SH basal salts but formed with increased frequency on medium supplemented with adenine sulfate, casamino acids (CA) and various combinations of cytokinins and auxins. Incubation in light was necessary for rhizome formation. Isolated basal as well as nodal (aerial) rhizomes formed and produced new shoots. In basal medium without any growth additives (control) the average number of shoots produced per inoculum was 3.3 ±0.73 whereas in the best suited medium i.e. supplemented with 250 mg l–1 CA the number of shoots obtained was 22.7±1.92. There was no dormancy period for rhizomes under the cultural conditions investigated. Rhizome-sprouts were easily transplanted from the in vitro conditions to the field. More than five hundred propagules (i.e. sprouted-rhizomes) were obtained within 5 months and it has been estimated that more than 2.4 × 105 propagules could be achieved per year through four subsequent in vitro rhizomes-generation cycles. Thus, a rapid method of propagation has been established.Abbreviations AdS Adenine sulphate - BA benzyladenine - CA casamino acids (vitamin free) - 2,4-D 2,4-dichlorophenoxyacetic acid - IAA indoleacetic acid - IBA indolebutyric acid - Kn Kinetin - NAA naphthaleneacetic acid - SH Schenk and Hildebrandt's medium (1972)  相似文献   

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The taxonomy of Lepisorus (J. Sm.) Ching sect. Lepisorus in China was revised based on herbarium specimen examinations, field observations, and microscopic study of rhizome scales, soral paraphyses, leaf epidermis, and spores. As a result, nine species were recognized: Lepisorus macrosphaerus (Baker) Ching, Lepisorus asterolepis (Baker) Ching, Lepisorus marginatus Ching, Lepisorus kuchenensis (Y.C. Wu) Ching, Lepisorus megasorus (C. Chr.) Ching, Lepisorus kawakamii (Hayata) Tagawa, Lepisorus subsessilis Ching & Y.X. Lin, Lepisorus affinis Ching, and Lepisorus nudus (Hook.) Ching. Lepisorus kawakamii (Hayata) Tagawa was reinstated; Lepisorus gyirongensis Ching & S.K. Wu and Lepisorus longus Ching were reduced to synonyms ofL. nudus and L. affinis, respectively. The subdivision ofLepisorus macrosphaerus was not accepted. Rhizome scales and paraphyses are the most useful characters for species delimitation as well as for infrageneric classification. Characteristics of the leaf epidermis and spore ornamentation are usually stable and thus of great significance in understanding the relationships among groups within the genus.  相似文献   

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Our phytochemical investigation of the whole plants of Medinilla septentrionalis (W. W. Sm.) H. L. Li led to the isolation of five tannins (15), five phenolic acids and phenolic acid derivatives (610), four flavonoids (1114), two triterpenes (15 and 16), and one hydantoin derivative (17). The structures of the obtained compounds were identified using spectrometric methods (1H NMR, 13C NMR and MS). This is the first study reporting on the chemical constituent of M. septentrionalis and the chemotaxonomic relationships between Medinilla and other genera of Melastomataceae.  相似文献   

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The taxonomy of Lepisorus (J. Sm.) Ching sect. Lepisorus in China was revised based on herbarium specimen examinations, field observations, and microscopic study of rhizome scales, soral paraphyses, leaf epidermis and spores. As a result nine species were recognized: Lepisorus macrosphaerus (Baker) Ching, L. asterolepis (Baker) Ching, L. marginatus Ching, L. kuchenensis (Y. C. Wu) Ching, L. megasorus(C. Chr.) Ching, L. kawakamii (Hayata) Tagawa, L. subsessilis Ching & Y. X. Lin, L. affinis Ching and L. nudus (Hook.) Ching. Lepisorus kawakamii (Hayata) Tagawa was reinstated; L. gyirongensis Ching & S. K. Wu and L. longus Ching were reduced to synonyms of L. nudus and L. affinis respectively. The subdivision of L. macrosphaerusis was not accepted. Rhizome scales and paraphyses are the most useful characters for species delimitation as well as for infrageneric classification. Characteristics of the leaf epidermis and spore ornamentation are usually stable and thus of great significance in understanding the relationships among groups within the genus.  相似文献   

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Summary The paper presents results of a growth chamber progeny test of selected phenotypically superior trees from two white spruce (Picea glauca (Moench.) Voss.) populations in central Newfoundland, Canada. On the basis of heritability of 11 juvenile characters the superior trees have been demonstrated to be suitable as a base population for continued advanced generation breeding. Family selection would produce good genetic gains in the first generation but these can be enhanced considerably by selection of best individuals within the best families for clonal propagation in the second generation or propagation by seed in the second and subsequent generations.  相似文献   

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