Genetic differentiation and spatial structure of Geosmithia morbida, the causal agent of thousand cankers disease in black walnut (Juglans nigra)

2013 ◽  
Vol 60 (2) ◽  
pp. 75-87 ◽  
Author(s):  
Denita Hadziabdic ◽  
Lisa M. Vito ◽  
Mark T. Windham ◽  
Jay W. Pscheidt ◽  
Robert N. Trigiano ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Spatial Structure ◽  
Black Walnut ◽  
Causal Agent ◽  
Juglans Nigra ◽  
Geosmithia Morbida ◽  
Thousand Cankers Disease

scholarly journals Virulence of Genetically Distinct Geosmithia morbida Isolates to Black Walnut and Their Response to Coinoculation with Fusarium solani

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 116-120 ◽  
Author(s):  
Rachael A. Sitz ◽  
Emily K. Luna ◽  
Jorge Ibarra Caballero ◽  
Ned A. Tisserat ◽  
Whitney S. Cranshaw ◽  
...  
Keyword(s):  
Disease Severity ◽  
Fusarium Solani ◽  
Black Walnut ◽  
Causal Agent ◽  
Geosmithia Morbida ◽  
Thousand Cankers Disease ◽  
Synergistic Response

Geosmithia morbida is well documented as the causal agent of thousand cankers disease of black walnut trees. However, it is not well understood how G. morbida strains differ in virulence and how their interactions with co-occurring pathogens contribute to disease severity. In this study, we systematically investigated virulence of genetically distinct G. morbida strains. Overall, we found varying degrees of virulence, although differences were not related to genetic groupings. Furthermore, the pathogen Fusarium solani is also commonly isolated from thousand canker-diseased trees. The degree of disease contribution from F. solani is unknown, along with interactions it may have with G. morbida. This research shows that coinoculation with these pathogens does not yield a synergistic response.

scholarly journals Effect of Geosmithia morbida Isolate and Temperature on Canker Development in Black Walnut

2012 ◽  
Vol 13 (1) ◽  
pp. 11 ◽  
Author(s):  
Emily Freeland ◽  
Whitney Cranshaw ◽  
Ned Tisserat
Keyword(s):  
Black Walnut ◽  
Juglans Nigra ◽  
Geosmithia Morbida ◽  
Rdna Its ◽  
Pityophthorus Juglandis ◽  
Thousand Cankers Disease ◽  
One Year ◽  
Old Trees ◽  
Canker Development ◽  
Walnut Twig Beetle

Thousand cankers disease of black walnut (Juglans nigra) is the result of aggressive feeding by the walnut twig beetle (Pityophthorus juglandis) and extensive cankering around beetle galleries caused by the fungus Geosmithia morbida. We developed a consistent, reproducible inoculation technique to screen black walnut trees for their reaction to canker development following inoculation with G. morbida. Canker areas in one-year-old trees were not affected by the location on the stem that inoculations were made. Differences in aggressiveness of G. morbida isolates, representing different rDNA ITS haplotype groups, to black walnut were observed in some experiments. However, these differences were small and evidence indicates that a single, highly aggressive haplotype is not responsible for the current TCD epidemic. Cankers formed in black walnut at all temperatures tested, but they were consistently smaller at 32/20°C day/night temperatures compared to 25/20°C. Although G. morbida is thermotolerant, higher temperatures may not enhance canker development. Accepted for publication 1 May 2012. Published 18 June 2012.

Development and characterization of sixteen microsatellite loci for Geosmithia morbida, the causal agent of thousand canker disease in black walnut (Juglans nigra)

2011 ◽  
Vol 4 (2) ◽  
pp. 287-289 ◽  
Author(s):  
Denita Hadziabdic ◽  
Phillip A. Wadl ◽  
Lisa M. Vito ◽  
Sarah L. Boggess ◽  
Brian E. Scheffler ◽  
...  
Keyword(s):  
Microsatellite Loci ◽  
Black Walnut ◽  
Causal Agent ◽  
Juglans Nigra ◽  
Canker Disease ◽  
Geosmithia Morbida

scholarly journals Methyl Bromide Fumigation to Eliminate Thousand Cankers Disease Causal Agents from Black Walnut

2019 ◽  
Vol 65 (4) ◽  
pp. 452-459
Author(s):  
Kendhl W Seabright ◽  
Scott W Myers ◽  
Stephen W Fraedrich ◽  
Albert E Mayfield ◽  
Melissa L Warden ◽  
...  
Keyword(s):  
Methyl Bromide ◽  
The United States ◽  
Black Walnut ◽  
Wood Products ◽  
Treatment Schedule ◽  
Geosmithia Morbida ◽  
Thousand Cankers Disease ◽  
Pathogen Recovery ◽  
Canker Development ◽  
Walnut Twig Beetle

Abstract Phytosanitary treatments for logs and barked wood products are needed to mitigate the spread of thousand cankers disease through the movement of these commodities. The disease threatens eastern black walnut (Juglans nigra L.) populations in the United States. It is caused by repeated attacks by the walnut twig beetle (Pityophthorus juglandis Blackman) and subsequent canker development caused by the fungal pathogen Geosmithia morbida M. Kolařík et al. Methyl bromide (MB) fumigations were evaluated for efficacy against P. juglandis and G. morbida in J. nigra bolts. Fumigation with 82 mg/L MB for 24 h at 4.5° C eliminated P. juglandis in J. nigra, but was ineffective against G. morbida. Subsequent experiments focused on eliminating G. morbida, but results were inconclusive because of low rates of pathogen recovery from naturally infested control bolts. Final experiments used J. nigra bolts artificially inoculated with G. morbida. Fumigations with 240 and 320 mg/L MB for 72 h at 10° C were effective in eliminating G. morbida from J. nigra bolts. Results confirm that the USDA fumigation treatment schedule for logs with the oak wilt pathogen will also mitigate the risk of spreading the thousand cankers disease vector and pathogen by movement of walnut bolts and wood products.

scholarly journals Detection of Geosmithia morbida on Numerous Insect Species in Four Eastern States

2019 ◽  
Vol 20 (3) ◽  
pp. 133-139 ◽  
Author(s):  
Melanie Moore ◽  
Jennifer Juzwik ◽  
Fredric Miller ◽  
Leah Roberts ◽  
Matthew D. Ginzel
Keyword(s):  
Bark Beetles ◽  
Adult Emergence ◽  
Juglans Nigra ◽  
Insect Species ◽  
Geosmithia Morbida ◽  
Pityophthorus Juglandis ◽  
Thousand Cankers Disease ◽  
Branch Dieback ◽  
Walnut Twig Beetle ◽  
Β Tubulin

Thousand cankers disease is caused by the coalescence of numerous Geosmithia morbida cankers on branches and stems of Juglans species, leading to branch dieback and eventual tree death. The fungus sporulates in galleries of the walnut twig beetle (Pityophthorus juglandis), allowing for acquisition of pathogen propagules and its subsequent transmission to other branches or trees following adult emergence. Recently, G. morbida has been isolated from Xylosandrus crassiusculus and Xyleborinus saxesenii collected in Ohio and Stenomimus pallidus collected in Indiana. These beetles are known to colonize diseased Juglans nigra in these states. In this study, an operational trap survey for ambrosia beetles, bark beetles, and other weevils was conducted in four eastern states, and captured beetles were assayed to detect G. morbida using both culture and PCR-based methods. A new primer pair (GmF3/GmR13), based on the β-tubulin region, was designed for G. morbida DNA detection. The pathogen was detected on 18 insect species using molecular methods, and live cultures were isolated from two species. This is the first report of the pathogen in Illinois and Minnesota.

Geosmithia morbida, Thousand Cankers Disease of Black Walnut Pathogen, Was Found for the First Time in Southwestern Ohio

2013 ◽  
Vol 14 (1) ◽  
pp. 36 ◽  
Author(s):  
John R. Fisher ◽  
David P. McCann ◽  
Nancy J. Taylor
Keyword(s):  
Black Walnut ◽  
Phytopathogenic Fungus ◽  
Geosmithia Morbida ◽  
Thousand Cankers Disease ◽  
First Time

Thousand cankers disease of walnut is a recently described disease caused by a newly described phytopathogenic fungus, Geosmithia morbida. G. morbida is now established in the Ohio landscape and has likely been present longer than initially suspected. Accepted for publication 28 October 2012. Published 1 December 2013.

scholarly journals De novo genome assembly of Geosmithia morbida, the causal agent of thousand cankers disease

2016 ◽  
Author(s):  
Taruna Aggarwal ◽  
Anthony Westbrook ◽  
Kirk Broders ◽  
Keith Woeste ◽  
Matthew D MacManes
Keyword(s):  
Genome Assembly ◽  
Fungal Pathogens ◽  
De Novo ◽  
Draft Genome ◽  
Black Walnut ◽  
De Novo Genome Assembly ◽  
Evolutionary Mechanisms ◽  
Geosmithia Morbida ◽  
Thousand Cankers Disease ◽  
Walnut Twig Beetle

Geosmithia morbida is a filamentous ascomycete that causes Thousand Cankers Disease in the eastern black walnut tree. This pathogen is commonly found in the western U.S.; however, recently the disease was also detected in several eastern states where the black walnut lumber industry is concentrated. G. morbida is one of two known phytopathogens within the genus Geosmithia, and it is vectored into the host tree via the walnut twig beetle. We present the first de novo draft genome of G. morbida. It is 26.5 Mbp in length and contains less than 1% repetitive elements. The genome possesses an estimated 6,273 genes, 277 of which are predicted to encode proteins with unknown functions. Approximately 31.5% of the proteins in G. morbida are homologous to proteins involved in pathogenicity, and 5.6% of the proteins contain signal peptides that indicate these proteins are secreted. Several studies have investigated the evolution of pathogenicity in pathogens of agricultural crops; forest fungal pathogens are often neglected because research efforts are focused on food crops. G. morbida is one of the few tree phytopathogens to be sequenced, assembled and annotated. The first draft genome of G. morbida serves as a valuable tool for comprehending the underlying molecular and evolutionary mechanisms behind pathogenesis within the Geosmithia genus. Keywords: de novo genome assembly, pathogenesis, forest pathogen, black walnut, walnut twig beetle.

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