Comparative studies on the disease prevalence and population dynamics of ginger blotch and brown blotch pathogens of button mushrooms

TY - JOUR

T1 - Comparative studies on the disease prevalence and population dynamics of ginger blotch and brown blotch pathogens of button mushrooms

AU - Taparia, Tanvi

AU - Hendrix, Ed

AU - Hendriks, Marc

AU - Krijger, Marjon

AU - De Boer, Wietse

AU - Van der Wolf, Jan

N1 - 7199, ME; Data archiving: property of WUR

PY - 2021

Y1 - 2021

N2 - Bacterial blotch is one of the most economically important diseases of button 'mushroom. Knowledge ofmechanisms of disease expression, inoculum thresholds, and disease management is limited to the most wellknown pathogen, Pseudomonas tolaasii. Recent outbreaks in Europe have been attributed to 'P. gingeri' and P. salomonii for ginger and brown blotch, respectively. Information about their identity, infection dynamics, and pathogenicity is largely lacking. The disease pressure in an experimental mushroom cultivation facility was evaluated for 'P. gingeri' and P. salomonii over varying inoculation densities, casing soil types, environmental humidity, and cultivation cycles. The pathogen population structures in the casing soils were simultaneously tracked across the cropping cycle using highly specific and sensitive TaqMan-quantitative PCR assays. 'P. gingeri' caused disease outbreaks at lower inoculum thresholds (104 CFU/g) in the soil than P. salomonii (105 CFU/g). Ginger blotch generically declined in later harvest cycles, although brown blotch did not. Casing soils were differentially suppressive to blotch diseases, based on their composition and supplementation. Endemic pathogen populations increased across the cultivation cycle although the inoculated pathogen populations were consistent between the first and second flush. In conclusion, 'P. gingeri' and P. salomonii have unique infection and population dynamics that vary over soil types. Their endemic populations are also differently abundant in peatbased casing soils. This knowledge is essential for interpreting diagnostic results from screening mushroom farms and designing localized disease control strategies.

AB - Bacterial blotch is one of the most economically important diseases of button 'mushroom. Knowledge ofmechanisms of disease expression, inoculum thresholds, and disease management is limited to the most wellknown pathogen, Pseudomonas tolaasii. Recent outbreaks in Europe have been attributed to 'P. gingeri' and P. salomonii for ginger and brown blotch, respectively. Information about their identity, infection dynamics, and pathogenicity is largely lacking. The disease pressure in an experimental mushroom cultivation facility was evaluated for 'P. gingeri' and P. salomonii over varying inoculation densities, casing soil types, environmental humidity, and cultivation cycles. The pathogen population structures in the casing soils were simultaneously tracked across the cropping cycle using highly specific and sensitive TaqMan-quantitative PCR assays. 'P. gingeri' caused disease outbreaks at lower inoculum thresholds (104 CFU/g) in the soil than P. salomonii (105 CFU/g). Ginger blotch generically declined in later harvest cycles, although brown blotch did not. Casing soils were differentially suppressive to blotch diseases, based on their composition and supplementation. Endemic pathogen populations increased across the cultivation cycle although the inoculated pathogen populations were consistent between the first and second flush. In conclusion, 'P. gingeri' and P. salomonii have unique infection and population dynamics that vary over soil types. Their endemic populations are also differently abundant in peatbased casing soils. This knowledge is essential for interpreting diagnostic results from screening mushroom farms and designing localized disease control strategies.

KW - Agaricus bisporus

KW - Casing soil

KW - Dose response

KW - Pathogenicity

KW - Pseudomonas 'gingeri'

KW - Pseudomonas salomonii

KW - Soil inoculum

KW - Soil-borne pathogens

KW - TaqMan-qPCR

KW - national

KW - Plan_S-Compliant_OA

U2 - 10.1094/PDIS-06-20-1260-RE

DO - 10.1094/PDIS-06-20-1260-RE

M3 - Article

C2 - 33021904

AN - SCOPUS:85101010127

SN - 0191-2917

VL - 105

SP - 542

EP - 547

JO - Plant Disease

JF - Plant Disease

IS - 3

ER -