title: Phylogenetic Analysis of Fusarium solani Associated with the Asian Longhorned Beetle, Anoplophora glabripennis.
abstract: Culture-independent analysis of the gut of a wood-boring insect, Anoplophora glabripennis (Coleoptera: Cerambycidae), revealed a consistent association between members of the fungal Fusarium solani species complex and the larval stage of both colony-derived and wild A. glabripennis populations. Using the translation elongation factor 1-alpha region for culture-independent phylogenetic and operational taxonomic unit (OTU)-based analyses, only two OTUs were detected, suggesting that genetic variance at this locus was low among A. glabripennis-associated isolates. To better survey the genetic variation of F. solani associated with A. glabripennis, and establish its phylogenetic relationship with other members of the F. solani species complex, single spore isolates were created from different populations and multi-locus phylogenetic analysis was performed using a combination of the translation elongation factor alpha-1, internal transcribed spacer, and large subunit rDNA regions. These analyses revealed that colony-derived larvae reared in three different tree species or on artificial diet, as well as larvae from wild populations collected from three additional tree species in New York City and from a single tree species in Worcester, MA, consistently harbored F. solani within their guts. While there is some genetic variation in the F. solani carried between populations, within-population variation is low. We speculate that F. solani is able to fill a broad niche in the A. glabripennis gut, providing it with fungal lignocellulases to allow the larvae to grow and develop on woody tissue. However, it is likely that many F. solani genotypes could potentially fill this niche, so the relationship may not be limited to a single member of the F. solani species complex. While little is known about the role of filamentous fungi and their symbiotic associations with insects, this report suggests that larval A. glabripennis has developed an intimate relationship with F. solani that is not limited by geographic location or host tree.
authors.affiliation: Tropical Crop and Commodity Protection Research Unit, USDA-ARS Pacific Basin Agricultural Research Center, 64 Nowelo Street, Hilo, HI 96720, USA. scott.geib@ars.usda.gov.
authors.forename: Scott M
authors.initials: SM
authors.lastname: Geib
authors.affiliation: Intercollege Program in Genetics at The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA. eds14@psu.edu.
authors.forename: Erin D
authors.initials: ED
authors.lastname: Scully
authors.affiliation: Department of Plant Pathology, The Pennsylvania State University, University Park, PA 16802, USA. jimenez-gasco@psu.edu.
authors.forename: Maria Del Mar
authors.initials: Mdel M
authors.lastname: Jimenez-Gasco
authors.affiliation: School of Forest Resources, The Pennsylvania State University, University Park, PA 16802, USA. jec16@psu.edu.|Department of Bioenergy Science and Technology (World Class University), Chonnam National University, Buk-Gu, Gwangju 500-757, Korea. jec16@psu.edu.
authors.forename: John E
authors.initials: JE
authors.lastname: Carlson
authors.affiliation: Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA. mxt3@psu.edu.
authors.forename: Ming
authors.initials: M
authors.lastname: Tien
authors.affiliation: Department of Entomology and Center for Chemical Ecology, The Pennsylvania State University, University Park, PA 16802, USA. kxh25@psu.edu.
authors.forename: Kelli
authors.initials: K
authors.lastname: Hoover
keywords: Nectria haematococca; fungal symbiosis; wood-feeding insect