Influence of host and geographic locale on the distribution of Colletotrichum cereale lineages.
Colletotrichum cereale is an ascomycete inhabitant of cool-season Pooideae grasses. The fungus has increased in frequency over the past decade as a destructive pathogen of Poa annua and Agrostis stolonifera turfgrass. Colletotrichum cereale exists as two lineages, designated clades A and B, but little is known about the distribution of these clades in natural environments, or what role these subdivisions may play in the trajectory of disease outbreaks. In this study, our objective was to determine the frequency of C. cereale clades A and B. To rapidly discriminate between the two C. cereale clades, a real-time PCR assay was developed based on the Apn2 gene. A collection of 700 C. cereale pathogens and endophytes from twenty Pooideae grass genera were genotyped. 87% of the collection was identifed as part of clade A, 11.7% as part of clade B, and 1.3% was a mixture. Colletotrichum cereale from turfgrass hosts in North America were most commonly members of clade A (78%). The overabundance of clade A in turfgrass isolates was directly attributable to the dominance of this lineage from southern sampling sites, irrespective of host. In contrast, 111 C. cereale turfgrass isolates collected from northern sampling sites were evenly distributed between clades A and B. Only 28% of C. cereale from A. stolonifera at northern sampling sites were part of clade A. These data show that environmental factors such as geographic location and host identity likely played a role in the distribution of the major C. cereale clades in North American turfgrass.
Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey, United States of America.
Lisa A
LA
Beirn
Department of Plant Biology and Pathology, Rutgers University, New Brunswick, New Jersey, United States of America.
Bruce B
BB
Clarke
Systematic Mycology and Microbiology Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, Maryland, United States of America.
Jo Anne
JA
Crouch
D020231:Colletotrichum / Q000235:genetics* / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000235:genetics; D003710:Demography; D005843:Geography; D054884:Host-Pathogen Interactions; D016015:Logistic Models; D009656:North America; D006109:Poaceae / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction; D013045:Species Specificity
D017931:DNA Primers; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase