About

Robert A. Blanchette is a professor in the Department of Plant Pathology at the University of Minnesota Twin Cities. He holds a PhD in plant pathology from Washington State University, an MS in forest pathology from the University of New Hampshire, and a BA in biology and botany from Merrimack College. His major research interests encompass forest pathology and wood microbiology, focusing on tree defense mechanisms, deterioration processes of wood, biotechnological uses of forest fungi, biological control of forest pathogens, and the conservation of archaeological and historic wood. Blanchette's research involves interdisciplinary approaches to understanding the biology and ecology of forest microbes and solving tree disease problems. His recent activities include leading expeditions to study fungi producing aerial rhizomorphs in the Ecuadorean Amazon, investigating fungi associated with the emerald ash borer in Minnesota, and studying native microorganisms inhibitory to the fungus causing white nose syndrome in bats. He is involved in projects on grapevine trunk diseases in Minnesota vineyards, as well as studies on fungi and decay in archaeological wood from Greenland, which are impacted by climate change. Blanchette's work also includes investigations on Ganoderma species in the US and Uruguay, and he is completing a dissertation on Heterobasidion Root Disease in Minnesota. His research contributes significantly to understanding forest fungi, wood decay, and disease management.

Research topics

• Ecology
• Botany
• Biology

Selected publications

• Filamentous fungal communities associated with the eastern larch beetle (<i>Dendroctonus simplex</i> LeConte) in Minnesota, including new Ophiostomatales species

  Figshare · 2026-02-26

  datasetOpen accessSenior author

  The eastern larch beetle (<i>Dendroctonus simplex</i> LeConte) is a native and historically nonaggressive inhabitant of <i>Larix laricina</i> trees in North America. Since 2001, however, <i>D. simplex</i> has experienced an uncharacteristic and prolonged outbreak that has impacted trees on approximately 90% of the <i>L. laricina</i> forests in Minnesota. To investigate the fungal communities within <i>D. simplex</i> galleries during this outbreak, we isolated fungi from 56 <i>D. simplex</i>–infested trees across seven sites in Minnesota. We recovered 45 fungal species, including four new species in the order Ophiostomatales, proposed as <i>Graphilbum insulare</i>, sp. nov., <i>Ophiostoma itasca</i>, sp. nov., <i>Ophiostoma minnesotense</i>, sp. nov., and <i>Ophiostoma pseudoips</i>, sp. nov. Additionally, based on phylogenetics and morphological traits, we recommend a new taxonomic classification for <i>Leptographium simplex</i>, comb. nov. previously described as <i>Graphium simplex</i> from <i>D. simplex</i> galleries in Vermont, USA. At the community level, most isolates were in the phylum Ascomycota (82% of the total relative abundance), followed by Basidiomycota (12%). The most frequently isolated orders were Ophiostomatales (59% of the total relative abundance), Hypocreales (9%), and Pleosporales (8%). One species, <i>Grosmannia americana</i>, accounted for more than half of all isolates recovered. These results improve our understanding of the fungi associated with a bark beetle outbreak and an understudied tree species.

  PublisherDOI

• Filamentous fungal communities associated with the eastern larch beetle (<i>Dendroctonus simplex</i> LeConte) in Minnesota, including new Ophiostomatales species

  Open MIND · 2026-02-26

  datasetSenior author

  The eastern larch beetle (<i>Dendroctonus simplex</i> LeConte) is a native and historically nonaggressive inhabitant of <i>Larix laricina</i> trees in North America. Since 2001, however, <i>D. simplex</i> has experienced an uncharacteristic and prolonged outbreak that has impacted trees on approximately 90% of the <i>L. laricina</i> forests in Minnesota. To investigate the fungal communities within <i>D. simplex</i> galleries during this outbreak, we isolated fungi from 56 <i>D. simplex</i>–infested trees across seven sites in Minnesota. We recovered 45 fungal species, including four new species in the order Ophiostomatales, proposed as <i>Graphilbum insulare</i>, sp. nov., <i>Ophiostoma itasca</i>, sp. nov., <i>Ophiostoma minnesotense</i>, sp. nov., and <i>Ophiostoma pseudoips</i>, sp. nov. Additionally, based on phylogenetics and morphological traits, we recommend a new taxonomic classification for <i>Leptographium simplex</i>, comb. nov. previously described as <i>Graphium simplex</i> from <i>D. simplex</i> galleries in Vermont, USA. At the community level, most isolates were in the phylum Ascomycota (82% of the total relative abundance), followed by Basidiomycota (12%). The most frequently isolated orders were Ophiostomatales (59% of the total relative abundance), Hypocreales (9%), and Pleosporales (8%). One species, <i>Grosmannia americana</i>, accounted for more than half of all isolates recovered. These results improve our understanding of the fungi associated with a bark beetle outbreak and an understudied tree species.

  DOI

• Evaluation of Wood Decay and Identification of Fungi Found in the USS Cairo, a Historic American Civil War Ironclad Gunboat

  Journal of Fungi · 2025-10-11

  articleOpen access1st authorCorresponding

  Studies of microbial degradation of historic woods are essential to help protect and preserve these important cultural properties. The USS Cairo is a historic Civil War gunboat and one of the first steam-powered and ironclad ships used in the American Civil War. Built in 1861, the ship sank in the Yazoo River of Mississippi in 1862 after a mine detonated and tore a hole in the port bow. The ship remained on the river bottom and was gradually buried with sediments for over 98 years. After recovery of the ship, it remained exposed to the environment before the first roofed structure was completed in 1980, and it has been displayed under a tensile fabric canopy with open sides at the Vicksburg National Military Park in Vicksburg, Mississippi. Concerns over the long-term preservation of the ship initiated this investigation to document the current condition of the wooden timbers, identify the fungi that may be present, and determine the elemental composition resulting from past wood-preservative treatments. Micromorphological characteristics observed using scanning electron microscopy showed that many of the timbers were in advanced stages of degradation. Eroded secondary cell walls leaving a weak framework of middle lamella were commonly observed. Soft rot attack was prevalent, and evidence of white and brown rot degradation was found in some wood. DNA extraction and sequencing of the ITS region led to the identification of a large group of diverse fungi that were isolated from ship timbers. Soft rot fungi, including Alternaria, Chaetomium, Cladosporium, Curvularia, Xylaria and others, and white rot fungi, including Bjerkandera, Odontoefibula, Phanerodontia, Phlebiopsis, Trametes and others, were found. No brown rot fungi were isolated. Elemental analyses using induced coupled plasma spectroscopy revealed elevated levels of all elements as compared to sound modern types of wood. High concentrations of boron, copper, iron, lead, zinc and other elements were found, and viable fungi were isolated from this wood. Biodegradation issues are discussed to help long-term conservation efforts to preserve the historic ship for future generations.

  PublisherOA PDFDOI

• Does Emerald Ash Borer Infestation Alter Ash Phloem Microbial Communities over Time?

  Phytobiomes Journal · 2025-12-16

  articleOpen accessSenior author

  The emerald ash borer (EAB), Agrilus planipennis, is a destructive invasive insect of North American ash ( Fraxinus). Although microorganisms associated with the beetle may contribute to tree decline and death, the microbial community succession during an EAB attack is unknown. We repeatedly sampled the bottom 2 m of green ash ( Fraxinus pennsylvanica) and black ash ( Fraxinus nigra) in seven stands across an infestation gradient over 4 years. Amplicon libraries were sequenced from control phloem tissue of trees showing no symptoms of infestation, uninfested phloem of trees with EAB, infested phloem (galleries), frass, and larvae to determine if there are shifts in the fungal and bacterial communities as trees succumb to EAB attack. We found that the control phloem communities significantly differed from the beetle-infested phloem in both species. Furthermore, as EAB progressed in its attack from the top limbs to the tree's base, the microbial communities in uninfested phloem outside the galleries shifted away from communities in the phloem of control trees. In infested phloem, more than 80% of the detected taxa were absent from control trees (i.e., most taxa were non-latent). However, the relative abundance of latent taxa in infested phloem was higher than the relative abundance of the non-latent taxa, especially for potential canker-causing fungi, which increased 21-fold and 32-fold in black ash and green ash trees, respectively. These findings provide valuable insight into how a woodboring beetle shapes the microbial environment within trees over time, influencing the overall microbial diversity, such as canker-causing and wood decay taxa. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

  PublisherDOI

• Red star rust (<i>Gymnosporangium yamadae</i>) on <i>Malus</i> spp. in United States public gardens

  Acta Horticulturae · 2025-06-01

  article
  PublisherDOI

• Fungi Associated with Dying Buckthorn in North America

  Forests · 2025-07-11

  articleOpen accessSenior author

  Common buckthorn (Rhamnus cathartica L.) is a small tree that forms dense stands, displacing native plant species and threatening natural forest habitats in its introduced range in North America. Removal via cutting is labor intensive and often ineffective due to vigorous resprouting. Although chemical control methods are effective, they can negatively affect sensitive ecosystems. A mycoherbicide that selectively kills buckthorn would provide an additional method for control. In the present study, fungi were collected from dying buckthorn species (Frangula alnus Mill., Rhamnus cathartica, Ventia alnifolia L’Hér) located at 19 sites across Minnesota and Wisconsin for their potential use as mycoherbicides for common buckthorn. A total of 412 fungi were isolated from samples of diseased tissue and identified via DNA extraction and sequencing. These fungi were identified as 120 unique taxa belonging to 81 genera. Of these fungi, 46 species belonging to 26 genera were considered to be canker or root-rot pathogens of woody plants, including species in Cytospora, Diaporthe, Diplodia, Dothiorella, Eutypella, Fusarium, Hymenochaete, Irpex, Phaeoacemonium, and others. A future study testing the pathogenicity of these putative pathogens of buckthorn is now needed to assess their utility as potential mycoherbicide agents for control of common buckthorn.

  PublisherDOI

• Aquatic <i>Xylaria</i> : an exotic fungus introduced into the United States on aquarium decorative wood

  Mycologia · 2025-02-13 · 3 citations

  article1st authorCorresponding

  is an ecologically versatile species, capable of thriving in diverse environments, including artificial habitats such as freshwater aquariums.

  PublisherDOI

• Surveys of nurseries, forests and waterways in Minnesota revealed the presence of 14 new records of <i>Phytophthora</i> species

  Canadian Journal of Plant Pathology · 2025-08-01

  articleSenior author
  PublisherDOI

• Intercontinental movement of exotic fungi on decorative wood used in aquatic and terrestrial aquariums

  Scientific Reports · 2025-03-17 · 2 citations

  articleOpen access1st authorCorresponding

  The intercontinental movement of fungi or fungus-like organisms brings nonnative species into areas where they may become invasive pathogens of trees and other plants. In the past century, many examples such as Dutch elm disease, sudden oak death, laurel wilt, and others have resulted in large economic losses and ecological disasters. Although various safeguards to prevent the transport of potential pathogens have been in effect, new avenues of introduction have occurred causing new disease outbreaks. This study examined fungi in wood shipped from Asia that is used for decorative purposes in aquatic and terrestrial aquariums. From 44 imported wood samples, 202 cultures representing 123 different fungal taxa were obtained and identified using molecular methods. These included 31 species not previously reported in the United States, 21 potential plant pathogens, 37 species of wood decay fungi and 24 taxa with a 97% sequence match or less to known isolates suggesting these are unknown species. The results demonstrate that wood used for decorative purposes in aquariums harbor large numbers of diverse fungi that remain viable during shipping and storage. These fungi are currently being imported into areas where they are not native, and they may pose serious biosecurity threats to the United States and other countries around the world.

  PublisherOA PDFDOI

• Fungal and Bacterial Communities of the Red Turpentine Beetle (Dendroctonus valens LeConte) in the Great Lakes Region, USA

  Forests · 2025-10-19 · 1 citations

  articleOpen accessSenior author

  Fungi and bacteria associated with bark beetles can facilitate successful tree colonization, and, in some cases, these fungi act as pathogens of trees. The red turpentine beetle (RTB, Dendroctonus valens) is a bark beetle native to North America that colonizes stressed pines, rarely killing healthy trees. The fungal communities associated with RTB adults, larval galleries, and control tree phloem from red pine (Pinus resinosa) and white pine (P. strobus) forests in the Great Lakes region of the United States were characterized using both culture-independent and culture-dependent methods. Similarly, the bacterial communities associated with RTB adults in the same region were characterized using a culture-independent method. There were significant differences between the adult beetle fungal communities and the tree-based fungal communities. Culture-independent sequencing of RTB adults showed high abundances of the fungal order Filobasidiales (red pine: 28.71% relative abundance, white pine: 6.91% relative abundance), as well as the bacterial orders Enterobacterales (red pine: 53.72%, white pine: 22.15%) and Pseudomonadales (red pine: 15.86%, white pine: 12.91%). In contrast, we isolated high amounts of fungi in the orders Pleosporales (red pine: 21.79%, white pine: 15.90%) and Eurotiales (red pine: 15.38%, white pine: 16.51%) from the adult beetles by culturing. Culture-independent sequencing of beetle galleries yielded high abundances of fungi in the orders Helotiales (red pine: 22.23%, white pine: 23.21%), whereas culture-based isolation from the same galleries yielded high amounts of Eurotiales (red pine: 17.91%, white pine: 17.91%), Hypocreales (red pine: 16.42%, white pine: 16.42%), and Ophiostomatales (red pine: 23.39%, white pine: 23.39%). This contrasts with the culture-independent method, where, likely due to limitations in the sequencing method, the Ophiostomatales accounted for only around 2% of the fungi from RTB galleries in both pine species. We observed a high species-level diversity of Ophiostomatales associated with RTB, isolating 14 species from the Great Lakes region. Leptographium terebrantis, a species that has been described in association with RTB throughout the United States, was the most common species (e.g., &gt;35% of the Ophiostomatales relative abundance in red pine environments and &gt;14% of the Ophiostomatales relative abundance in the white pine environment). This study enhances our understanding of RTB-associated fungi and bacteria in the beetle’s native range at both the community and species levels.

  PublisherOA PDFDOI

Recent grants

• Dimensions U.S.-China: The role of symbiotic microbes in the invasion process of emerald ash borer and red turpentine beetle

  NSF · $1.4M · 2021–2026

• Studies of Antarctic Fungi: Adaptive Stratigies for Survival and Protecting Antarctica's Historic Structures

  NSF · $403k · 2006–2010

• Collaborative Research: Functional and evolutionary bases of substrate-specificity in wood-decaying basidiomycetes

  NSF · $167k · 2015–2019

Frequent coauthors

• Benjamin W. Held

  University of Minnesota

  72 shared

• T. R. Filley

  39 shared

• Roberta L. Farrell

  University of Waikato

  33 shared

• Igor V. Grigoriev

  Lawrence Berkeley National Laboratory

  31 shared

• Michael J. Wingfield

  University of Pretoria

  20 shared

• Todd A. Burnes

  University of Minnesota

  20 shared

• Elizabeth Simpson

  MemorialCare Health System

  20 shared

• David S. Hibbett

  Clark University

  19 shared

Labs

• Department of Plant PathologyPI