A 6kb rDNA probe comprising the 18S coding plusspacer sequences has been hybridized to the metaphase chromosomes of apple rootstock cultivar MM106 demon-strating the localization of ribosomal gene arrays in the vicini...A 6kb rDNA probe comprising the 18S coding plusspacer sequences has been hybridized to the metaphase chromosomes of apple rootstock cultivar MM106 demon-strating the localization of ribosomal gene arrays in the vicinity of the telomeric regions of the short arms of chro-mosomes 6 and 14. The in situ results using digoxygenin labelling coupled to an alkaline phosphatase immunoassay were confirmed by silver staining for NORs and nucleoli. This study demonstrates the feasibility of molecular cyto-genetic analysis of very small chromosomes (1.0-2.7μm)of apple.展开更多
Four new species of Hymenoscyphus (H. brevicellulus, H. hyaloexcipulus, H. microcaudatus, and H. subsymmetricus) and a new Chinese record (H. subpallescens) are described. These five species share common characteristi...Four new species of Hymenoscyphus (H. brevicellulus, H. hyaloexcipulus, H. microcaudatus, and H. subsymmetricus) and a new Chinese record (H. subpallescens) are described. These five species share common characteristics: small apothecia (<3mm in diameter); hymenium whitish, pale yellow, to yellow in color; ectal excipulum of textura prismatica; asci arising from simple septa; ascospores scutuloid and guttulate; saprophytic nutrition; and leaf habitats, except for H. subsymmetricus, which grows on herbaceous stems. Phylogenetic analyses of internal transcribed spacer nuclear ribosomal DNA sequences, the universal DNA barcode for fungi, for 16 species in the genus indicated that these taxa were closely related to H. microserotinus, in accordance with their morphological features, but represented independent species. The distinguishing features of each new species from its relatives are discussed, and their phylogenetic relationships explored.展开更多
文摘A 6kb rDNA probe comprising the 18S coding plusspacer sequences has been hybridized to the metaphase chromosomes of apple rootstock cultivar MM106 demon-strating the localization of ribosomal gene arrays in the vicinity of the telomeric regions of the short arms of chro-mosomes 6 and 14. The in situ results using digoxygenin labelling coupled to an alkaline phosphatase immunoassay were confirmed by silver staining for NORs and nucleoli. This study demonstrates the feasibility of molecular cyto-genetic analysis of very small chromosomes (1.0-2.7μm)of apple.
基金supported by the National Natural Science Foundation of China (31070015,31093440)the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX2-EW-J-6)
文摘Four new species of Hymenoscyphus (H. brevicellulus, H. hyaloexcipulus, H. microcaudatus, and H. subsymmetricus) and a new Chinese record (H. subpallescens) are described. These five species share common characteristics: small apothecia (<3mm in diameter); hymenium whitish, pale yellow, to yellow in color; ectal excipulum of textura prismatica; asci arising from simple septa; ascospores scutuloid and guttulate; saprophytic nutrition; and leaf habitats, except for H. subsymmetricus, which grows on herbaceous stems. Phylogenetic analyses of internal transcribed spacer nuclear ribosomal DNA sequences, the universal DNA barcode for fungi, for 16 species in the genus indicated that these taxa were closely related to H. microserotinus, in accordance with their morphological features, but represented independent species. The distinguishing features of each new species from its relatives are discussed, and their phylogenetic relationships explored.
