首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
3.
4.
Ohne Zusammenfassung  相似文献   

5.
6.
A locally severe crown disease of exotic plantation Eucalyptus trees has been recorded periodically in New Zealand since 1986. Symptoms include leaf spots, petiole infection and twig and small branch lesions. Outbreaks of disease are episodic and individual trees may show marked variation in crown symptoms ranging from unaffected to total defoliation. Two previously unknown species of Phytophthora are associated with the disease. These are described and formally designated here as P. captiosa, from Eucalyptus botryoides and E. saligna; and P. fallax, from E. delegatensis, E. fastigata, E. nitens and E. regnans. Both P. captiosa and P. fallax have non-papillate, non-caducous sporangia and both are self-fertile. Phylogenetic analysis on the basis of ITS rDNA sequence data indicates they are closely related to each other but evolutionarily distant from the majority of described Phytophthora taxa. They share a common ancestor with another assemblage of Phytophthora lineages that includes P. insolita, P. macrochlamydospora and P. richardiae. Sporulation of P. captiosa and P. fallax has not been observed in the field. The mode of infection and spread of these non-caducous Phytophthora species in the eucalypt tree canopy remains unknown. This issue, and the possible geographic origins of these two Phytophthora species are discussed.  相似文献   

7.
8.
Twenty arthroconidial yeasts were isolated from the digestive tract of basidiome-feeding beetles and lepidopteran larvae. All of the yeasts reproduced only asexually by arthroconidia and some by endo- or blastoconidia as well. Based on the comparisons of sequences in ribosomal RNA genes and other taxonomic characteristics, the yeasts were identified as three unknown Geotrichum species. The three new species are described as Geotrichum carabidarum (NRRL Y-27727T), G. histeridarum (NRRL Y-27729T), and G. cucujoidarum (NRRL Y-27731T). Phylogenetic analyses from ribosomal DNA sequences showed that members of the genus Geotrichum and related arthroconidial yeast taxa were divided into two major clades: (1) Dipodascus and Galactomyces with Geotrichum anamorphs including all the new species; and (2) Magnusiomyces with Saprochaete anamorphs. G. cucujoidarum formed a subclade with G. fermentans and Geotrichum sp. Y-5419, while the two closely related species, G. carabidarum and G. histeridarum, represent a new basal subclade in the clade of Geotrichum and its teleomorphs.  相似文献   

9.
10.
11.
In a taxonomic study of yeasts isolated from decaying plant materials submerged in water of mangrove forests in Thailand, three strains isolated from tree bark (EM33T), a fallen leaf (EM40T) and a detached branch (SM56T) were found to represent three novel yeast species. On the basis of morphological, biochemical, physiological and chemotaxonomic characteristics, the sequence analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene, and the phylogenetic analysis, the three strains were assigned as three novel Candida species. They were named as Candida chanthaburiensis sp. nov. (type strain EM33T = BCC 23057T = NBRC 102176T = CBS 10926T), Candida kungkrabaensis sp. nov. (type strain EM40T = BCC 23060T = NBRC 102179T = CBS 10927T), and Candida suratensis sp. nov. (type strain SM56T = BCC 25961T = NBRC 103858T = CBS 10928T).  相似文献   

12.
13.
14.
Evidence suggests that truffle-like sporocarp forms have evolved many times in the Pezizales, but primarily from epigeous ancestors within ectomycorrhizal clades. There are several ectomycorrhizal clades, however, that contain no known hypogeous species. We collected specimens of an unusual unidentified truffle from mixed oak woodlands in Iowa. Although clearly a member of the Pezizales (Ascomycota), this hypogeous species did not belong to any of the described truffle genera. Based on a combination of ecological, phylogenetic, and morphological evidence we determined that this new truffle is a hypogeous member of the genus Otidea (Pyronemataceae), a lineage with no described truffle species. We describe it here as a new species, Otidea subterranea.  相似文献   

15.
16.
17.
18.
Yasuo Suto 《Mycoscience》2009,50(5):357-368
Three species belonging to the genus Rhytisma causing tar spot were collected on leaves in evergreen trees of Ilex species from Japan. Rhytisma ilicis-latifoliae, the known species, is found on Ilex latifolia, and R. ilicis-integrae sp. nov. and R. ilicis-pedunculosae sp. nov. are found on I. integra and I. pedunculosa, respectively. Ascomata are formed on the abaxial part of the stromata in all the Rhytisma species studied, and spermogonia are formed on the amphigenous parts in R. ilicis-latifoliae and on the adaxial part in R. ilicis-integrae and R. ilicis-pedunculosae. Shape and size of asci, ascospores, and spermatia are distinctly different among the three species. The morphology of germination tubes from ascospores and appressoria is unique for each Rhytisma species. Yellowish spots arise on the newly developing leaves in mid-May, then abundant spermatia are produced in spermogonia in the three Rhytisma species. In the next year, ascospores are produced in ascomata from early April to late May in R. ilicis-integrae and from early April to early June in R. ilicis-latifoliae and R. ilicis-pedunculosae, and they are considered to be the inocula of disease infection.  相似文献   

19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号