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The sterol fractions of eight leafy liverworts were analyzed by GLC and GC-MS. Five 3β-sterols, cholest-5-en-3β-ol, 24-methylcholest-5,22-dien-3β-ol, 24-methylcholest-5-en-3p-ol, 24-ethylcholest-5,22-dien-3β-ol and 24-ethylcholest-5-en-3β-ol, were detected in all samples but there were differences in the relative amounts present.  相似文献   

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Pollen morphology of the Thymelaeaceae in relation to its taxonomy   总被引:1,自引:0,他引:1  
 Pollen morphology of the four subfamilies of Thymelaeaceae sensu Domke (1934) was examined using LM, SEM and TEM. The variation of the exine architecture allows to distinguish four pollen types and three subtypes. Distribution of pollen types proves to be widely correlated with the occurrence of characters from wood anatomy and flower morphology. If pollen types are connected with subfamilies sensu Domke (1934), Gonystyloideae, Thymelaeoideae and Synandrodaphnoideae are stenopalynous, whereas Aquilarioideae are eurypalynous. Based on pollen morphology as well as on other characters it is evident that Aquilarioideae are not monophyletic. Its genera Aquilaria and Gyrinops are more closely related to Thymelaeoideae and Synandrodaphnoideae than to other genera of Aquilarioideae sensu Domke (1934). The remaining genera of Aquilarioideae Deltaria, Solmsia and Lethedon are most similar to Gonystyloideae and therefore are included in this subfamily, as it was suggested by Airy Shaw (1979). Furthermore, palynological and other characters favour the transfer of Octolepis from Aquilarioideae to Gonystyloideae. The re-circumscribed Aquilarioideae together with Thymelaeoideae and Synandrodaphnoideae are shown to form a monophyletic group. Received August 8, 2001 Accepted December 7, 2001  相似文献   

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Cell-free extracts of 17 strains of Bifidobacterium bifidum (Lactobacillus bifidus) were examined for the presence of aldolase, glucose-6-phosphate dehydrogenase, and fructose-6-phosphate phosphoketolase. All strains turned out to lack aldolase, an enzyme unique to glycolysis, and glucose-6-phosphate dehydrogenase, characteristic of the hexosemonophosphate pathway. In all strains, fructose-6-phosphate phosphoketolase could be demonstrated. It can be concluded that bifidobacteria ferment glucose via a pathway which is different from those found in members of the genus Lactobacillus. The results strengthen the previous suggestions that classification of the bifidobacteria in the genus Lactobacillus is not justified.  相似文献   

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Recent evidence on craniodental morphology suggests the acceptance of three species of lion tamarins (Leontopithecus). Confirmatory evidence is presented here using the morphology of long-call vocalizations recorded from several individuals of each type of lion tamarin. Recordings were made of Leontopicthecus rosalia, Leontopithecus chrysopygus, and Leontopithecus chrysomelas at the Centro de Primatologia do Rio de Janeiro (FEEMA) and of L. rosalia at Monkey Jungle in Florida. Thirty separate parameters were measured, and 17 of them differed significantly between populations. In general, L. chrysomelas had higher pitched calls with shorter note duration, while L. chrysopygus, the larger of the animals, had lower pitched calls with longer note duration. L. rosalia was either intermediate to the other two populations or resembled L. chrysopygus. Thus, the results from the analysis of vocal structures closely paralleled the results obtained with more traditional taxonomic methods and suggests that the quantitative analysis of vocal strucures can be a useful adjunct in taxonomy.  相似文献   

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The production of mucidin by the basidiomyceteOudemansiella mucida was negatively influenced by the application of D-glucitol as the main carbon source, the effect being independent of the growth rate of the mycelium. The rate of fatty acid synthesis was measured by incorporation of 1-14C-acetate. After 8 days of cultivation, the amount of fatty acids was approximately half that synthetized during cultivation on glucose. The specific rate of incorporation reached its maximum after seven days of cultivation. Incorporation of 2-14C-mevalonate into sterols was the same under the two sets of cultivation conditions. Acetate units from the degraded fatty acids are probably also utilized for antibiotic synthesis.  相似文献   

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The pollen morphology of some native Greek Aegilops species is investigated in LM (quantitative pollen characters) and SEM (exine sculpture) using acetolysed material. Furthermore, quantitative data are subjected to a multivariate analysis. The tetraploid Ae. cylindrica and its diploid parent Ae. caudata show a distinct morphological affinity as regards their quantitative pollen profile and the features of the exine sculpture. The tetraploid Ae. triuncialis is morphologically divergent from both its parents Ae. caudata and Ae. umbellulata due to the very large values of its quantitative pollen characters. However, the SEM survey of the exine sculpture indicates a rather high degree of similarity between Ae. triuncialis and Ae. umbellulata. No significant differences have been found between the two varieties of Ae. caudata (caudata and polyathera) concerning the quantitative pollen characters as a total or the morphology of the exine sculpture. The resultant clustering of the taxa on the basis of the quantitative pollen characters as well as the recorded similarities of their exine pattern are related to their sectional classification based on cytogenetical and morphological data.  相似文献   

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The results of a comparative survey on pollen morphology in theBoragineae by means of light, scanning and transmission electron microscopy are presented and discussed in relation to the taxonomy of the tribe. Multivariate analyses lead to the recognition of 15 pollen morphotypes for which a discriminant key is proposed. The discriminatory characters concern mainly the stereostructural and ultrastructural features of the grains, such as tectum sculpture and aperture morphology, while the number of apertures appears variable within genera and even single species. Seven out of the 12 investigated genera, as currently circumscribed, are matched by palynological data:Anchusella, Borago, Brunnera, Elizaldia, Lithodora, Symphytum andTrachystemon. On account of aperture shape,Lithodora is however closer to theLithospermeae than to theBoragineae. Other genera, and in particularNonea, show a wide variation in tectum ornamentation, shape of grains and number of apertures. Palynological data do not support a broad concept of the genusAnchusa, and point to the autonomy of the satellite generaHormuzakia, Gastrocotyle, Phyllocara, Pentaglottis andCynoglottis.  相似文献   

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Maternal allocation of antioxidants to egg yolk has been shown to affect early embryonic development and nestling survival. In environments with high levels of anthropogenic pollution, antioxidants (such as carotenoids) are important to protect the body from elevated oxidative stress. Thus, female allocation of antioxidants to yolk may be traded off against self-maintenance. Here we investigate maternal reproductive investment with respect to yolk carotenoid content and composition in relation to subsequent female condition and carotenoid status in urban and rural great tits Parus major. We found no differences between the urban and rural populations in total yolk carotenoids, egg mass, clutch size, hatching success, or female carotenoid status. Interestingly, however, rural eggs contained more zeaxanthin, a more potent antioxidant than lutein, which suggests that rural embryos have better antioxidant protection than urban embryos. Whether rural females actively transfer more zeaxanthin to the yolk or whether it passively reflects differences in dietary access or uptake needs to be further investigated. This highlights the importance of carotenoid identity and composition in future studies of carotenoid physiology, ecology, and signaling.  相似文献   

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A study of ultrathin sections ofMicrococcus denitrificans andM.halodenitrificans has shown similar cell structures. The cell wall consists of several layers corresponding to those of the cell wall of gram-negative bacteria. The thickness of the cell wall is 250 – 350 Å; that of the cytoplasmic membrane 70 Å. The cytoplasm in both species contains ribosomes and inclusions of polymetaphosphate. Comparison with ultrathin sections ofThiobacillus novellus shows too much difference to consider the former two species to be identical with the latter one. The taxonomic position ofM.denitrificans andM.halodenitrificans is discussed.Deceased 3 July 1967.  相似文献   

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