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1.
Stylogyne carautae Carrijo & M. F. Freitas is described and illustrated as a new endemic species from south-eastern Brazil. The relationships between S. carautae and S. depauperata Mez are discussed, and comments on their ecology and conservation are provided.  相似文献   

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Aquatic Metschnikowia species (M. australis, M. bicuspidata, M. krissii, and M. zobellii) are sensitive to 10 out of 12 mycocins secreted by Pichia membranifaciens strains. Terrestrial species M. pulcherrima and M. reukaufii are resistant to all these mycocins, while M. gruessii and M. lunata are sensitive to one of them. The yeast described as Torula rubifaciens is also sensitive to this mycocin.  相似文献   

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Mentzelia hualapaiensis, a new species of Mentzelia sect. Bartonia, is described from the Grand Canyon region of Arizona. The new species is closely related to M. puberula, which is found west of M. hualapaiensis along the Colorado River, and to M. oreophila, M. polita, and M. tiehmii. It shares with these species a suffrutescent shoot system characterized by a subterranean, branching caudex, multiple annual branches, and similar leaves that have shallowly lobed or toothed to entire laminas. The flowers of M. hualapaiensis differ from those of its closest relatives in having cream-white, linear to narrowly spatulate petals and staminodes, characteristics that are convergent with those of the flowers of the Chihuahuan Desert species M. humilis.  相似文献   

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Seven hundred fifty-four strains of mycobacteria were examined using 97 characters, and a “Hypothetical Mean Organism” (HMO) was prepared for each species using numerical classification. The species could be defined as a group of strains showing a mean S-value of 90% or more to a HMO and showing mean S-values of 89% or less to other HMOs. The following species were recognized: (1) M. tuberculosis, combining M. tuberculosis and M. bovis into one species; (2) M. kansasii; (3) M. novum; (4) M. avium, combining M. avium, M. nonchromogenicum, M. gastri, M. intracellulare and M. scrofulaceum into one species; (5) M. marinum; (6) M. thermoresistibile; (7) M. chitae; (8) M. borstelense; (9) M. abscessus; (10) M. fortuitum; (11) M. phlei; (12) M. aurum; (13) M. parafortuitum; (14) M. lacticola; (15) M. smegmatis. Dendrogram of the species showed two main stems, indicating that the genus Mycobacterium be divided into two subgenera, subgenus Mycobacterium (from M. tuberculosis to M. chitae) and subgenus My cornycobacterium (from M. borstelense to M. smegmatis). Some discrepancy was noted between the results of numerical classification using HMOs and that of the “proper” numerical classification, and this discrepancy is discussed.  相似文献   

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Phosphorus release from Microcystis aeruginosa and attached bacterium (Pseudomonas sp.) isolated from Lake Taihu was examined using a phosphorus isotope tracer in order to investigate the phosphorus transference between the two species. Our results reveal that the amount of phosphorus released form 32P-saturated M. aeruginosa is determined by its growth phase and most of phosphorus is assimilated by Pseudomonas finally while the amount of phosphorus released from 32P-saturated Pseudomonas is also determined by the growth phase of M. aeruginosa and most of them are assimilated by M. aeruginosa. The results suggest that phosphorus transference occurs between M. aeruginosa and its attached Pseudomonas . This process makes microenvironment of mucilage of M. aeruginosa attached bacteria maintain relative high amounts of phosphorus. Attached bacteria may be a temporary phosphorus bank to the growth of M. aeruginosa, and assimilation of phosphorus by M. aeruginosa becomes easy when M. aeruginosa is in lag growth phase. Thus, the phosphorus exchange between M. aeruginosa and attached Pseudomonas in microenvironment may be important to microfood web and cyanobacteria bloom.  相似文献   

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Mammillaria species are the most numerous within Cactaceae family, and some of them are threatened with extinction as a result of human activities. In this work, results of in vitro propagation are presented for ten Mammillaria species, testing 20 combinations of indole-3-acetic acid (IAA) and kinetin. Best results on shoot formation were obtained using kinetin at two levels: 27.9 and 46.5 μM. All IAA levels tested were able to induce de novo shoot formation in M. bocasana, M. densispina, M. hahniana, M. hutchisoniana, M. orcutii, M. pectinifera, M. perbella, M. picta, M. rhodantha, and M. zephyranthoides. Depending on the IAA level tested, four responding groups were observed concerning their highest shoot-formation number. For all species, the highest average of shoot formation was achieved with 5.7:46.5 or 11.4:46.5 μM IAA/kinetin, yielding 4.8 and 4.7 shoots per explant, respectively, in 60 d. Rooting of regenerated shoots was achieved by leaving the explants in their shoot-induction medium or transferring them to half-strength MS medium. Hardening of regenerated plants was successfully achieved by planting them in peat moss substrate after a desiccation treatment at room temperature for 3 d.  相似文献   

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Maireina afibulata and M. attenuatipilis are proposed as new members of the recently revised genus Maireina, one of the few anatomically well-studied cyphelloid groups in the Basidiomycota. Maireina species have brownish basidiomes, smooth, parietally unpigmented spores, and are characterized by non-ramified external hyphae with more or less thick, yellow to brown cell walls and distinct crystalline incrustations that always include their distal ends. A key to the species of the genus Maireina is presented, and M. afibulata as well as M. attenuatipilis are described and discussed in detail. Taxonomic novelties: Maireina afibulata Bodensteiner, M. attenuatipilis Bodensteiner  相似文献   

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Taxonomic studies of Brazilian Meriania species (Merianieae – Melastomataceae) have identified taxonomic and nomenclatural gaps. The present work proposes one new synonym, M. sanchezii, for M. paniculata; one new neotypification of M. glabra; and five lectotypifications for M. calophylla, M. glabra var. parviflora (= M. glabra), M. paniculata, M. pergamentacea (= M. robusta), and M. urceolata.  相似文献   

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Two new species of Lonchocarpus from Brazil, assigned to sect. Laxiflori Benth., are described and illustrated and their affinities, geographical distribution and conservation status are discussed. Lonchocarpus laticiferus from arboreal caatinga vegetation of Bahia State, and deciduous forest of Minas Gerais State is related to L. montanus A. M. G. Azevedo ex M. J. Silva & A. M. G. Azevedo. Lonchocarpus graciliflorus, known only from the rain forest of Paraná, is morphologically similar to L. longiunguiculatus M. J. Silva & A. M. G. Azevedo.  相似文献   

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Summary  Seven new names at species rank are proposed in Memecylon sect. Afzeliana Jacq.-Fél., a group of forest shrubs and small trees confined to Guineo-Congolian Africa. The group is centred in Cameroon, where 17 of the 20 species occur. A new flower type, the “star-flower” in Memecylon is revealed, and its taxonomic and ecological importance discussed. Three new, locally endemic species from the South West Province of Cameroon are described, mapped and illustrated: M. kupeanum R. D. Stone, Ghogue & Cheek, M. bakossiense R. D. Stone, Ghogue & Cheek, and M. rheophyticum R. D. Stone, Ghogue & Cheek. Two new names, M. accedens R. D. Stone, Ghogue & Cheek and M. hyleastrum R. D. Stone & Ghogue and one new combination, M. mamfeanum (Jacq.-Fél.) R. D. Stone, Ghogue & Cheek are provided at species level for three taxa originally proposed as varieties of M. afzelii G. Don. The taxon M. arcuatomarginatum var. simulans Jacq.-Fél. is also elevated to species status, as M. simulans (Jacq.-Fél.) R. D. Stone & Ghogue. Conservation assessments are provided for all the newly named taxa. A key is provided to the species of Memecylon sect. Afzeliana.  相似文献   

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In a previous study, using a primer set designed from Mycoplasma fermentans, we amplified a PCR fragment from Mycoplasma orale similar to the 206-bp DNA fragment amplified from M. fermentans insertion-sequence-like element (ISLE). The presence of this similar ISLE fragment has the potential to cause confusion in the PCR diagnosis of M. fermentans and M. orale, which have significantly different clinical scenarios. An ISLE from three different M. orale strains was amplified by using a primer set designed from sequence within the left and right terminal stem and loop (S&L) structures flanking the ISLE of M. fermentans. Sequence analysis showed that the M. orale ISLE is 93% identical to that of M. fermentans at the nucleotide level and codes for two open reading frames also found in the M. fermentans ISLE. This is the first finding that two different mycoplasma species harbor highly homologous IS elements. This finding has great significance in clinical diagnosis and suggests a possibility of horizontal transfer of an IS element between two different mycoplasma species. Received: 17 April 2002 / Accepted: 9 July 2002  相似文献   

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Butterflies of the highly endangered genus Maculinea are parasites of red Myrmica ants. Prior to the adoption by Myrmica worker ants Maculinea caterpillars feed on a specific host plant. This field study aims to answer the question whether the density and distribution of the host plant Sanguisorba officinalis or the density of the host ant M. rubra limit the density of M. nausithous egg, larval and adult stage. We found that the density of M. nausithous egg stage and adult stage increased with the density of the host ant. The density of M. nausithous caterpillars was not associated with ant density or plant density. This study suggests that the density of M. nausithous is limited by the density of the host ant M. rubra. We conclude that habitat management for M. nausithous should focus on the maintenance of habitats that hold both resources, but that enable high densities of M. rubra. In addition, it is discussed why high densities of host ants might be more important in predatory than in cuckoo-feeding Maculinea.  相似文献   

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Maculinea butterflies are social parasites of Myrmica ants. Methods to study the strength of host ant specificity in the MaculineaMyrmica association include research on chemical and acoustic mimicry as well as experiments on ant adoption and rearing behaviour of Maculinea larvae. Here we present results of laboratory experiments on adoption, survival, development and integration of M. teleius larvae within the nests of different Myrmica host species, with the objective of quantifying the degree of specialization of this Maculinea species. In the laboratory, a total of 94 nests of four Myrmica species: M. scabrinodis, M. rubra, M. ruginodis and M. rugulosa were used. Nests of M. rubra and M. rugulosa adopted M. teleius larvae more readily and quickly than M. ruginodis colonies. No significant differences were found in the survival rates of M. teleius larvae reared by different ant species. Early larval growth of M. teleius larvae differed slightly among nests of four Myrmica host species. Larvae reared by colonies of M. rugulosa which were the heaviest at the beginning of larval development had the lowest mean larval body mass after 18 weeks compared to those reared by other Myrmica species. None of the M. teleius larvae was carried by M. scabrinodis or M. rubra workers after ant nests were destroyed, which suggests a lack of integration with host colonies. Results indicate that Myrmica species coming from the same site differ in their ability to adopt and rear M. teleius larvae but there was no obvious adaptation of this butterfly species to one of the host ant species. This may explain why, under natural conditions, all four ants can be used as hosts of this butterfly species. Slight advantages of particular Myrmica species as hosts at certain points in butterfly larval development can be explained by the ant species biology and colony structure rather than by specialization of M. teleius.  相似文献   

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Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism.  相似文献   

20.
Our recent molecular phylogenetic study revealed a previously unrecognized clade of six species that is sister to Elaphoglossum. Within this clade, four species are currently classified in Bolbitis, one in Lomagramma, and one in Acrostichum. For this clade, we propose the name Mickelia, with M. nicotianifolia as the type species. We also make new combinations for the species in our phylogenetic study shown to belong to Mickelia (M. bernoullii, M. guianensis, M. hemiotis, M. nicotianifolia, M. oligarchica, and M. scandens) and two other species believed to belong to the clade based on morphology (M. lindigii, M. pergamentacea). A new hybrid and two new species are also described (M. ×atrans, M. furcata, and M. pradoi). In total, Mickelia consists of ten species and one hybrid. It is entirely neotropical. We provide a key to the genera of bolbitidoid ferns and a synopsis of Mickelia that gives for each species a complete synonymy, geographical distribution, comparative discussion, and illustration.  相似文献   

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