U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.


Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Main content area

Real-Time PCR Detection of Clarireedia spp., the Causal Agents of Dollar Spot in Turfgrasses

Crouch Joanne, Glen Groben, Bruce B. Clarke, James Murphy, Paul Koch, Jo Anne Crouch, Sangkook Lee, Ning Zhang
Plant disease 2020 v.104 no.12 pp. 3118-3123
Agrostis stolonifera, fungi, internal transcribed spacers, leaves, new genus, new species, pathogens, quantitative polymerase chain reaction, ribosomal DNA, soil, taxonomic revisions, thatch, turf grasses
Dollar spot is one of the most economically important diseases of turfgrasses. Recent taxonomic revisions have placed the dollar spot fungal pathogens in the new genus Clarireedia, with five species described. The main goal of this study was to develop a quantitative real-time PCR (qPCR) molecular detection assay based on the internal transcribed spacer (ITS) of the ribosomal RNA genes to quantify the abundance of Clarireedia spp. from environmental (field) samples. The qPCR assay was able to detect isolates of the four tested Clarireedia spp. but did not cross react with nontarget fungi, including closely related taxa, other turfgrass pathogens, or other fungal species commonly isolated from turfgrass. The assay is capable of detecting as little as 38.0 fg (3.8 × 10⁻¹⁴ g) of Clarireedia genomic DNA in 3 h. The qPCR assay detected Clarireedia spp. in both symptomatic and asymptomatic creeping bentgrass (Agrostis stolonifera) foliar tissue. Clarireedia spp. were rarely detected in the thatch or soil, indicating that these pathogens are not widely distributed in these areas of the environment. The fact that the pathogen was detected in asymptomatic tissue suggests that creeping bentgrass may be able to tolerate a certain quantity of the pathogens in leaves before disease symptoms appear; however, further research is needed to validate this hypothesis.
Data from: Clarireedia: A new fungal genus comprising four pathogenic species responsible for dollar spot disease of turfgrass