title: Isolation and identification of endophytic and mycorrhizal fungi from seeds and roots of Dendrobium (Orchidaceae).
abstract: The seed germination of orchids under natural conditions requires association with mycorrhizal fungi. Dendrobium nobile and Dendrobium chrysanthum are threatened orchid species in China where they are considered medicinal plants. For conservation and application of Dendrobium using symbiosis technology, we isolated culturable endophytic and mycorrhizal fungi colonized in the protocorms and adult roots of two species plants and identified them by morphological and molecular analyses (5.8S and nrLSU). Of the 127 endophytic fungi isolated, 11 Rhizoctonia-like strains were identified as Tulasnellales (three strains from protocorms of D. nobile), Sebacinales (three strains from roots of D. nobile and two strains from protocorms of D. chrysanthum) and Cantharellales (three strains from roots of D. nobile), respectively. In addition, species of Xylaria, Fusarium, Trichoderma, Colletotrichum, Pestalotiopsis, and Phomopsis were the predominant non-mycorrhizal fungi isolated, and their probable ecological roles in the Dendrobium plants are discussed. These fungal resources will be of great importance for the large-scale cultivation of Dendrobium plants using symbiotic germination technology and for the screening of bioactive metabolites from them in the future.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, People's Republic of China. chenjuan@implad.ac.cn
authors.forename: Juan
authors.initials: J
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Shun-Xing
authors.initials: SX
authors.lastname: Guo
mesh_terms: D002681:China; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D031667:Dendrobium / Q000382:microbiology*; D005658:Fungi / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D020459:Genes, rRNA; D029595:Orchidaceae; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology*; D012331:RNA, Fungal / Q000235:genetics; D012335:RNA, Ribosomal / Q000235:genetics; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D012639:Seeds / Q000382:microbiology*; D017422:Sequence Analysis, DNA
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D012331:RNA, Fungal; D012335:RNA, Ribosomal; D012340:RNA, Ribosomal, 5.8S; C065096:RNA, ribosomal, 26S