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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Publications at this Location » Publication #329695

Research Project: Systematics and Diagnostics of Emerging and Quarantine-Significant Plant Pathogenic Fungi

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Phylogeny of Hirsutella species (Ophiocordycipitaceae) from the USA: remedying the paucity of Hirsutella sequence data

Author
item Simmons, Rabern - University Of Florida
item Kepler, Ryan
item Rehner, Stephen
item Groden, Eleanor - University Of Maine

Submitted to: IMA Fungus
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2015
Publication Date: 12/1/2015
Citation: Simmons, R.D., Kepler, R.M., Rehner, S.A., Groden, E. 2015. Phylogeny of Hirsutella species (Ophiocordycipitaceae) from the USA: remedying the paucity of Hirsutella sequence data. IMA Fungus. 6(2):345-356.

Interpretive Summary: Insect pests cause billions of dollars of agricultural losses annually. The use of beneficial fungi to control insects can reduce reliance on chemical pesticides that are expensive and damaging to the environment and human health. In this study we used DNA to determine the relationships and differences within a group of fungi parasitic on a a wide range of insects, including species of plant pests. DNA sequencing results demonstrated that a genus of insect pathogenic fungi includes multiple unrelated clusters of species. This information will lead toward more accurate classifications that will enable greater accuracy in the identification of important insect pathogens. This information will be used by insect mycologists and plant pathologists developing and implementing integrated pest management strategies of field crop pests.

Technical Abstract: Hirsutella (Ophiocordycipitaceae: Hypocreales) is a genus of insect, mite, and nematode pathogens with an asexual morph, which generally produce a mucilaginous cluster of one or several conidia on phialides that are basally subulate and taper to a fine neck. The generic name Hirsutella has been proposed for suppression in favour of Ophiocordyceps as a consequence of the ending of dual nomenclature for different morphs of pleomorphic fungi in 2011. Though the generic name is well established, geographically dispersed, and speciose, exceptionally few sequences are available in online databases. We examined 46 isolates of 23 Hirsutella species from the USA, curated by the USDA-ARS Collection of Entomopathogenic Fungal Cultures (ARSEF Culture Collection), that previously had not been molecularly characterized and produced a phylogeny of these organisms; we included previously published Hirsutella and Ophiocordyceps taxa. In producing the largest phylogeny of Hirsutella isolates so far, we provide: (1) context for discussing previously-hypothesized relationships; (2) evidence for revisions as taxonomic transitions move forward; and (3) available molecular data to be incorporated into further evolutionary studies of Ophiocordycipitaceae.