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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #340566

Research Project: Identification, Characterization, and Deployment of Genes Important during Seed Development in Legumes

Location: Crop Production and Pest Control Research

Title: Confirmation of independent introductions of an exotic plant pathogen of Cornus species, Discula destructiva, on the east and west coasts of North America and subsequent population bottlenecks

item MANTOOTH, KRISTIE - University Of Tennessee
item HADZIABDIC, DENITA - University Of Tennessee
item BOGGESS, SARAH - University Of Tennessee
item WINDHAM, MARK - University Of Tennessee
item MILLER, STEPHEN - Rutgers University
item Cai, Guohong
item SPATAFORA, JOSEPH - Oregon State University
item ZHANG, NING - Rutgers University
item STATON, MEG - University Of Tennessee
item OWNLEY, BONNIE - University Of Tennessee
item TRIGIANO, ROBERT - University Of Tennessee

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2017
Publication Date: 7/26/2017
Citation: Mantooth, K., Hadziabdic, D., Boggess, S., Windham, M., Miller, S., Cai, G., Spatafora, J., Zhang, N., Staton, M., Ownley, B., Trigiano, R. 2017. Confirmation of independent introductions of an exotic plant pathogen of Cornus species, Discula destructiva, on the east and west coasts of North America and subsequent population bottlenecks. PLoS One. 12(7): e0180345. doi:10.1371/journal.pone.0180345.

Interpretive Summary: Eastern flowering dogwood and pacific flowering dogwood are tree species native to North America and highly-prized ornamentals. Dogwood anthracnose, caused by the fungus Discula destructiva, is a very devastating disease on these trees. It was first observed on pacific flowering dogwood in Washington State in 1976 and on eastern flowering dogwood in New York in 1977. There were different theories about how this disease originated in North America. This study examined the population structure of the pathogen and concluded that the fungus was an exotic species and independently introduced into east and west coasts. Understanding how the disease spread is important to designing and implementing preventive measures and control strategies.

Technical Abstract: Cornus florida (eastern flowering dogwood) and C. nuttallii (pacific flowering dogwood) are North American native tree species that belong to the big-bracted group of dogwoods. Cornus species are highly valued for their ornamental characteristics, have fruits that contain high fat content for animals. Also, they are an important understory tree in natural forests. Dogwood anthracnose, caused by Discula destructiva, was observed in the late 1970s on the east and West coasts of the United States and by 1991 had quickly spread throughout much of the native ranges of C. florida and C. nuttalli. We investigated the genetic diversity and population structure of 93 D. destructiva isolates using 47 microsatellite loci developed from the sequenced genome of the type strain of D. destructiva. Clone-corrected data indicated low genetic diversity and the presence of four genetic clusters that corresponded to two major geographic areas, the eastern United States and the Pacific Northwest, and to the two collection time periods when the isolates were collected. Linkage disequilibrium was present in five out of six subpopulations, suggesting that the fungus only reproduced asexually. Evidence of population bottlenecks was indicated across four identified genetic clusters, and was probably the result of the limited number of founding individuals on both coasts. These results support the hypothesis that D. destructiva is an exotic pathogen with independent introductions on the East and West coasts of North America. We also tested the cross-transferability of these microsatellite markers to other Discula species. Genomic DNA from 17 isolates of five other Discula species and two isolates of Juglanconis species (formerly Melanconis species) amplified with 17 of 47 primer pairs. These primers may be useful for investigating the genetic diversity and population structure of these Discula species.