TY - JOUR
T1 - Venturia inaequalis trapped: molecular quantification of airborne inoculum using volumetric and rotating arm samplers
AU - Torfs, Sanne
AU - Van Poucke, Kris
AU - Van Campenhout, Jelle
AU - Ceustermans, An
AU - Croes, Sarah
AU - Bylemans, Dany
AU - Van Hemelrijck, Wendy
AU - Keulemans, Wannes
AU - Heungens, Kurt
PY - 2019/12/1
Y1 - 2019/12/1
N2 - Site-specific high throughput monitoring of airborne ascospores of Venturia inaequalis, the causal agent of apple scab, can improve existing warning systems. A new qPCR assay was developed to quantify ascospores collected by a simple rotating-arm spore sampler. The qPCR assay was highly specific and sensitive, with a limit of quantification of 20 ascospores per sample. The new detection system was compared to sampling with a traditional Burkard volumetric spore trap and to microscopic quantification. During controlled ascospore release experiments in a closed environment, strong correlations (ρ: 0.96 to 0.99) were observed between the two types of samplers and the two methods of quantification but significantly larger numbers of spores (log difference: 0.43 to 0.69) were obtained when using the rotating-arm sampler and when using molecular quantification. During comparisons under outdoor conditions over a three-year period, reasonable correlations between the techniques (average ρ = 0.61) were observed. When rotating-arm samplers operate continuously they can get saturated but their counts still correlated better with those from the Burkard sampler than when they only operate during rain and until two hours after. This suggests that ascospores were also captured outside of rain events. Based on these comparisons, molecular quantification of spores captured with the rotating-arm sampler appears to be a sensitive and reliable method to determine airborne ascospores of V. inaequalis and holds promise as a tool to guide targeted fungicide applications in commercial orchards as well as to increase our knowledge of the aerobiology of this pathogen.
AB - Site-specific high throughput monitoring of airborne ascospores of Venturia inaequalis, the causal agent of apple scab, can improve existing warning systems. A new qPCR assay was developed to quantify ascospores collected by a simple rotating-arm spore sampler. The qPCR assay was highly specific and sensitive, with a limit of quantification of 20 ascospores per sample. The new detection system was compared to sampling with a traditional Burkard volumetric spore trap and to microscopic quantification. During controlled ascospore release experiments in a closed environment, strong correlations (ρ: 0.96 to 0.99) were observed between the two types of samplers and the two methods of quantification but significantly larger numbers of spores (log difference: 0.43 to 0.69) were obtained when using the rotating-arm sampler and when using molecular quantification. During comparisons under outdoor conditions over a three-year period, reasonable correlations between the techniques (average ρ = 0.61) were observed. When rotating-arm samplers operate continuously they can get saturated but their counts still correlated better with those from the Burkard sampler than when they only operate during rain and until two hours after. This suggests that ascospores were also captured outside of rain events. Based on these comparisons, molecular quantification of spores captured with the rotating-arm sampler appears to be a sensitive and reliable method to determine airborne ascospores of V. inaequalis and holds promise as a tool to guide targeted fungicide applications in commercial orchards as well as to increase our knowledge of the aerobiology of this pathogen.
KW - Aerial spore sampling
KW - Apple scab
KW - Burkard spore trap
KW - Rotating-arm spore trap
KW - qPCR
UR - http://www.mendeley.com/research/venturia-inaequalis-trapped-molecular-quantification-airborne-inoculum-using-volumetric-rotating-arm
UR - https://rdcu.be/b8NyB
U2 - 10.1007/s10658-019-01858-0
DO - 10.1007/s10658-019-01858-0
M3 - A1: Web of Science-artikel
SN - 0929-1873
VL - 155
SP - 1319
EP - 1332
JO - European Journal of Plant Pathology
JF - European Journal of Plant Pathology
IS - 4
ER -