title: Colonization of roots of cultivated Solanum lycopersicum by dark septate and other ascomycetous endophytes.
abstract: Tomato (Solanum lycopersicum L.) roots from four different crop sites in Colombia were surface sterilized and 51 fungal isolates were obtained and conserved for further analysis. Based on microscopical observations and growth characteristics, 20 fungal isolates corresponded to genus Fusarium, six presented asexual conidia different from Fusarium, eight were sterile mycelia, seven of which had dark septate hyphae and 17 did not continue to grow on plates after being recovered from conservation. Growth on different media, detailed morphological characterization and ITS region sequencing of the six sporulating and eight sterile isolates revealed that they belonged to different orders of Ascomycota and that the sterile dark septate endophytes did not correspond to the well known Phialocephala group. Interactions of nine isolates with tomato plantlets were assessed in vitro. No effect on shoot development was revealed, but three isolates caused brown spots in roots. Colonization patterns as analyzed by confocal microscopy differed among the isolates and ranged from epidermal to cortical penetration. Altogether 11 new isolates from root endophytic fungi were obtained, seven of which showed features of dark septate endophytes. Four known morphotypes were represented by five isolates, while six isolates belonged to five morphotypes of putative new unknown species.
authors.affiliation: Leibniz-Institute of Vegetable and Ornamental Crops, Theodor-Echtermeyer-Weg 1, 14979 Grossbeeren, Germany.
authors.forename: Diana Rocio
authors.initials: DR
authors.lastname: Andrade-Linares
authors.forename: Rita
authors.initials: R
authors.lastname: Grosch
authors.forename: Philipp
authors.initials: P
authors.lastname: Franken
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Rexer
authors.forename: Gerhard
authors.initials: G
authors.lastname: Kost
authors.forename: Silvia
authors.initials: S
authors.lastname: Restrepo
authors.forename: Maria Caridad Cepero
authors.initials: MC
authors.lastname: de Garcia
authors.forename: Eugenia
authors.initials: E
authors.lastname: Maximova
mesh_terms: D001203:Ascomycota / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D001483:Base Sequence; D003105:Colombia; D018556:Crops, Agricultural / Q000382:microbiology; D021901:DNA, Intergenic / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005670:Fusarium / Q000254:growth & development; D025301:Hyphae / Q000254:growth & development; D018551:Solanum lycopersicum / Q000382:microbiology*; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D013172:Spores, Fungal / Q000254:growth & development; D013559:Symbiosis / Q000235:genetics
chemical_list: D021901:DNA, Intergenic; D021903:DNA, Ribosomal Spacer