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21.
Dendroctonus valens is an invasive pest in coniferous forests of northern China. It was suspected of being responsible for the death of more than three million Pinus tabuliformis trees. The present study sought to identify the ophiostomatoid fungi associated with D. valens in northern China and understand the possible role of these fungi in the pine decline. On the basis of morphology, physiology, mating compatibility and phylogenetic analyses of multiple DNA sequences, seven species of ophiostomatoid fungi were isolated from and around D. valens galleries: Leptographium alethinum, Grosmannia koreana (teleomorph of L. koreanum), L. procerum, L. sinoprocerum, L. truncatum, Pesotum aureum and P. pini. All have been recorded for the first time in China. Among them, the occurrence of the dominant species L. procerum is positively linked to attack intensities of D. valens. The pathogenicity of four species (L. koreanum, L. procerum, L. sinoprocerum and L. truncatum) was tested on mature P. tabuliformis trees by stem inoculation. All inoculated strains caused significant necrotic lesions on the inner bark. However, L. koreanum and L. truncatum induced more extensive lesions than L. procerum and L. sinoprocerum. Their association with D. valens and the P. tabuliformis decline is discussed.  相似文献   
22.
In the frame of a revision of the Fomitiporia species with pileate basidiomata in the New World, several collections originating from Andean, high elevation forests of Argentina were found to represent a terminal clade in multilocus phylogenetic inferences (including nuclear ribosomal partial LSU and ITS-5.8S, partial tef1-α and RPB2 genes). These collections also represent a singular morphotype within Fomitiporia, characterized by mostly pileate basidiomata, with a soft corky consistency, roughly sulcate pilei, a “duplex” context with a thin black line, and dextrinoid basidiospores, averaging 5.9?×?5.3 μm. It also has a well-marked autecology, occurring on shrubby trees in high elevation forests along the Andean range. A search in the literature for a name pointed toward Phellinus baccharidis, despite the fact that this species was repeatedly described with non-dextrinoid basidiospores. Examination of the type of P. baccharidis confirmed the main morphological features as previously described, but for the reaction of basidiospores in Melzer’s reagent, which was found to be strongly positive (dextrinoid), and an overall similarity with our own specimens; hence, the new combination Fomitiporia baccharidis is proposed. The species is redescribed and illustrated. It is so far known from Argentina and Ecuador. Its phylogenetic relationships with the South American Fomitiporia are briefly discussed.  相似文献   
23.
The Cu(II) complex formation equilibria of D- glucosamine were studied in aqueous solution by potentiometric and spectroscopic (ESR, CD, absorption spectra) techniques. All data agree that two major species are formed in the pH region 6–9 involving two D-glucosamine ligand molecules bound to the cupric ion via NH2(CuL2) or NH2 and O? (CuH?2L2). In the latter case deprotonated hydroxyls were found to be very effective coordination sites for Cu(II) giving rise to chelate complexes. On the contrary, no complex formation was observed for the Cu(II) N-acetyl-D-glucosamine system.  相似文献   
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Left main coronary occlusion is a rare lesion. A case that was successfully managed by coronary bypass surgery is presented. Occlusion of the left main coronary artery and management of left main coronary artery disease is discussed.  相似文献   
26.
In this report, we describe an 11-years-old girl with inverted duplication in the distal part of the long arm of chromosome 8 (inv dup(8)(q24.11----q24.3). The most remarkable finding is her borderline intelligence and her nearly normal phenotype.  相似文献   
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Phialomyces fusiformis sp. nov., isolated from soil in Singapore, is described and illustrated. The species is similar to P. macrosporus-type species of the genus but differs in that it has longer, more ellipsoid-limoniform, fusiform and more coarsely ornamented conidia.  相似文献   
29.
GC is commonly used for the analysis of cannabis samples, e.g. in forensic chemistry. However, as this method is based on heating of the sample, acidic forms of cannabinoids are decarboxylated into their neutral counterparts. Conversely, HPLC permits the determination of the original composition of plant cannabinoids by direct analysis. Several HPLC methods have been described in the literature, but most of them failed to separate efficiently all the cannabinoids or were not validated according to general guidelines. By use of an innovative methodology for modelling chromatographic responses, a simple and accurate HPLC/DAD method was developed for the quantification of major neutral and acidic cannabinoids present in cannabis plant material: Δ9-tetrahydrocannabinol (THC), THC acid (THCA), cannabidiol (CBD), CBD acid (CBDA), cannabigerol (CBG), CBG acid (CBGA) and cannabinol (CBN). Δ8-Tetrahydrocannabinol (Δ8-THC) was determined qualitatively. Following the practice of design of experiments, predictive multilinear models were developed and used in order to find optimal chromatographic analytical conditions. The method was validated following an approach using accuracy profiles based on β-expectation tolerance intervals for the total error measurement, and assessing the measurements uncertainty. This analytical method can be used for diverse applications, e.g. plant phenotype determination, evaluation of psychoactive potency and control of material quality.  相似文献   
30.
A chemotaxonomic evaluation using hplc profiling was undertaken to resolve the infrageneric and intergeneric affinities of over 150 strains of Xylariaceae. Daldinia placentiformis, Hypoxylon nicaraguense, H. polyporus, and Phylacia sagrana were found to contain 8-methoxy-1-naphthol, which is apparently absent in Annulohypoxylon, Hypoxylon, and related genera with bipartite stromata. D. placentiformis and other species of Daldinia and Entonaema produced this naphthol, 5-hydroxy-2-methylchromone, isosclerone derivatives, and ‘AB-5046’ phytotoxins. Phylacia sagrana differed from most Daldinia spp., except for D. caldariorum, by producing eutypine derivatives in addition to the above compounds. Indolylquinones were observed in H. nicaraguense and H. polyporus. Isosclerones were also identified in the A. multiforme complex, but Hypoxylon and other Annulohypoxylon and most Hypoxylon spp. studied Annulohypoxylon spp. contained 5-methylmellein as the major metabolite of their cultures. Based on the occurrence of the above metabolites, further mellein-type dihydroisocoumarins, teleomorphic and anamorphic Xylariaceae with Nodulisporium-like anamorphs (‘Hypoxyloideae’) were divided into various chemotypes. A comparison of their 5.8S/ITS nuc-rDNA sequences agreed in some important aspects with the above results: H. nicaraguense and H. polyporus appeared basal to a clade comprising Daldinia, Entonaema, and Ph. sagrana. The latter species appeared allied to D. caldariorum, but was distantly related to Pyrenomyxa morganii and Hypoxylon s. str.  相似文献   
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