title: Ambrosiella roeperi sp. nov. is the mycangial symbiont of the granulate ambrosia beetle, Xylosandrus crassiusculus.
abstract: Isolations from the granulate ambrosia beetle, Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae: Xyleborini), collected in Georgia, South Carolina, Missouri and Ohio, yielded an undescribed species of Ambrosiella in thousands of colony-forming units (CFU) per individual female. Partial sequences of ITS and 28S rDNA regions distinguished this species from other Ambrosiella spp., which are asexual symbionts of ambrosia beetles and closely related to Ceratocystis spp. Ambrosiella roeperi sp. nov. produces sporodochia of branching conidiophores with disarticulating swollen cells, and the branches are terminated by thick-walled aleurioconidia, similar to the conidiophores and aleurioconidia of A. xylebori, which is the mycangial symbiont of a related ambrosia beetle, X. compactus. Microscopic examinations found homogeneous masses of arthrospore-like cells growing in the mycangium of X. crassiusculus, without evidence of other microbial growth. Using fungal-specific primers, only the ITS rDNA region of A. roeperi was amplified and sequenced from DNA extractions of mycangial contents, suggesting that it is the primary or only mycangial symbiont of this beetle in USA.
authors.affiliation: Department of Plant Pathology and Microbiology, 351 Bessey Hall, Iowa State University, Ames, Iowa 50011 tcharrin@iastate.edu.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Harrington
authors.affiliation: Department of Plant Pathology and Microbiology, 351 Bessey Hall, Iowa State University, Ames, Iowa 50011.
authors.forename: Douglas
authors.initials: D
authors.lastname: McNew
authors.affiliation: Department of Plant Pathology and Microbiology, 351 Bessey Hall, Iowa State University, Ames, Iowa 50011.
authors.forename: Chase
authors.initials: C
authors.lastname: Mayers
authors.affiliation: Southern Research Station, USDA Forest Service, Athens, Georgia 30605.
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Fraedrich
authors.affiliation: Division of Plant Sciences, University of Missouri, Columbia, Missouri 65211.
authors.forename: Sharon E
authors.initials: SE
authors.lastname: Reed
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification; D001483:Base Sequence; D001517:Coleoptera / Q000382:microbiology*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D005260:Female; D005845:Georgia; D008923:Missouri; D008969:Molecular Sequence Data; D016533:Mycological Typing Techniques; D009820:Ohio; D017422:Sequence Analysis, DNA; D013022:South Carolina; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer
keywords: Ambrosiella hartigii; Anisandrus dispar; Cnestus mutilatus; Trypodendron; X. germanus; Xyleborini; Xylosandrus amputatus