Full TGIF Record # 310866
Item 1 of 1
Web URL(s):https://archive.lib.msu.edu/tic/ressum/2019/2019.pdf#page=293
    Last checked: 04/23/2020
    Requires: PDF Reader
    Notes: Item is within a single large file
Publication Type:
Author(s):Koch, Paul; Clarke, Bruce; Murphy, Jim; Jung, Geunhwa; Zhang, Ning
Author Affiliation:Koch: Department of Plant Pathology, University of Wisconsin - Madison; Clarke, Murphy, and Zhang: Department of Plant Biology and Pathology, Rutgers University; Jung: Stockbridge School of Agriculture, University of Massachusetts - Amherst
Title:Sclerotinia homoeocarpa epidemiology and resistance development as measured through improved molecular detection techniques
Section:Integrated turfgrass management
Other records with the "Integrated turfgrass management" Section

Other records with the "Pathology" Section
Source:Turfgrass and Environmental Research Program: 2019 Research Summaries. 2019, p. 285-303.
Publishing Information:[New York, New York]: The United States Golf Association Green Section
# of Pages:19
Keywords:TIC Keywords: Disease resistance; Dollar spot; Epidemiology; Molecular genetics; Polymerase chain reaction; Sclerotinia homoeocarpa
See Also:Other Reports from this USGA research project: 2018-20-670
Note:Pictures, color & b/w
USGA Summary Points:Dollar spot sampling sites were continued in New Jersey, Wisconsin, and Massachusetts and sampled repeatedly throughout the 2019 growing season. Two assays were developed for quantifying the dollar spot fungus in field samples. The first is a 'digital droplet PCR (ddPCR)' developed at Wisconsin that is new to Plant Pathology and represents a potentially significant advancement for the detection of fungal DNA in field samples. The second is a more common 'quantitative PCR (qPCR)' assay developed at Rutgers and Massachusetts that will provide an assay that nearly any research laboratory would be able to perform without the specialized equipment required of ddPCR. The qPCR methodology developed at Rutgers consistently detects all dollar spot (Clarireedia) species present in bentgrass shoot and thatch samples at very low levels, and does not result in false positives. The ddPCR protocol developed at Wisconsin was found to be highly sensitive and repeatable in Year 1, however the samples collected in 2019 have yet to be analyzed using due to staff turnover. The samples collected at Wisconsin in 2019 will be analyzed in late 2019 and early 2020. A rapid PCR-based assay was developed at Massachusetts that has effectively identified SDHI resistance in a variety of isolates collected from the Northeaster[n] US and Japan Two field studies were initiated at Wisconsin to test 1) the fungal population response to various fungicides with different modes of action and 2) the spatial distribution of the fungus over a small (1 m x 1 m) area in both symptomatic and non-symptomatic conditions. For the first study, samples were collected weekly from the first week of May through the last week of October, and a total of 288 samples were collected. For the second study, samples were collected in mid-May and again in August and totaled 216 samples. The DNA has been extracted from all samples in the first study but extractions are still ongoing in the second study. A subsample number of 8 to 16 one-cm diameter x two-cm deep cores were needed to attain a consistent and accurate representation of the pathogen population from a 6m2 turf plot in the field. The upper ~0.5-cm depth of individual sample cores, which contained lower leaf sheaths, the crown, and upper thatch appeared to be the best portion (subsample) of the core from which to isolate pathogen DNA for turf that had a relatively deep (~2.5 cm) thatch layer. qPCR analysis of samples containing leaf sheaths, crowns and 0.5-cm of surface thatch was able to detect a higher pathogen population on Independence creeping bentgrass (highly susceptible cultivar) compared to Declaration (resistant cultivar) when foliar symptoms were present (28 August 2019). However, homogenizing entire core samples that had a ~2.5-cm thick thatch layer resulted in the pathogen not being detected, presumably because DNA was diluted to the point of non-detection using qPCR. In a spatial distribution study, the dollar spot pathogen was present at low levels throughout the entire plot before disease was visable. A trial was initiated in fall 2019 to test the hypothesis (using the newly developed qPCR methodology) that fall fungicide applications reduce pathogen population and delay disease onset the next spring.
ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Koch, P., B. Clarke, J. Murphy, G. Jung, and N. Zhang. 2019. Sclerotinia homoeocarpa epidemiology and resistance development as measured through improved molecular detection techniques. USGA Turfgrass Environ. Res. Summ. p. 285-303.
Fastlink to access this record outside TGIF: https://tic.msu.edu/tgif/flink?recno=310866
If there are problems with this record, send us feedback about record 310866.
Choices for finding the above item:
Web URL(s):
    Last checked: 04/23/2020
    Requires: PDF Reader
    Notes: Item is within a single large file
Find Item @ MSU
MSU catalog number: b3609415
Request through your local library's inter-library loan service (bring or send a copy of this TGIF record)