title: Back-trajectory modelling and DNA-based species-specific detection methods allow tracking of fungal spore transport in air masses.
abstract: Recent advances in molecular detection of living organisms facilitate the introduction of novel methods to studies of the transport of fungal spores over large distances. Monitoring the migration of airborne fungi using microscope based spore identification is limited when different species produce very similar spores. In our study, DNA-based monitoring with the use of species-specific probes allowed us to track the aerial movements of two important fungal pathogens of oilseed rape (Brassica napus L.), i.e., Leptosphaeria maculans and Leptosphaeria biglobosa, which have identical spore shape and size. The fungi were identified using dual-labelled fluorescent probes that were targeted to a β-tubulin gene fragment of either Leptosphaeria species. Spore identification by Real-Time PCR techniques capable of detecting minute amounts of DNA of selected fungal species was combined with back-trajectory analysis, allowing the tracking of past movements of air masses using the Hybrid Single Particle Lagrangian Integrated Trajectory model. Over a study period spanning the previous decade (2006-2015) we investigated two specific events relating to the long distance transport of Leptosphaeria spp. spores to Szczecin in North-West Poland. Based on the above mentioned methods and the results obtained with the additional spore sampler located in nearby Szczecin, and operating at the ground level in an oilseed rape field, we have demonstrated that on both occasions the L. biglobosa spores originated from the Jutland Peninsula. This is the first successful attempt to combine analysis of back-trajectories of air masses with DNA-based identification of economically important pathogens of oilseed rape in Europe. In our studies, the timing of L. biglobosa ascospore dispersal in the air was unlikely to result in the infection of winter oilseed rape grown as a crop plant. However, the fungus could infect other host plants, such as vegetable brassicas, cruciferous weeds, spring rapeseed and winter rapeseed growing as a volunteer plant.
authors.affiliation: Department of Plant Taxonomy and Phytogeography, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Grinn-Gofroń
authors.affiliation: Rothamsted Research, West Common, Harpenden, Hertfordshire AL5 2JQ, UK.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sadyś
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, 60-479 Poznan, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kaczmarek
authors.affiliation: Department of Plant Taxonomy and Phytogeography, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Bednarz
authors.affiliation: Department of Plant Taxonomy and Phytogeography, University of Szczecin, Wąska 13, 71-415 Szczecin, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Pawłowska
authors.affiliation: Institute of Plant Genetics, Polish Academy of Sciences, Strzeszynska 34, 60-479 Poznan, Poland. Electronic address: mjed@igr.poznan.pl.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Jedryczka
mesh_terms: D000391:Air Microbiology; D001203:Ascomycota / Q000235:genetics / Q000302:isolation & purification*; D029688:Brassica napus / Q000382:microbiology*; D004271:DNA, Fungal / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D008962:Models, Theoretical; D010935:Plant Diseases / Q000382:microbiology*; D011044:Poland; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D013045:Species Specificity; D013172:Spores, Fungal / Q000302:isolation & purification
chemical_list: D004271:DNA, Fungal
keywords: DNA-based detection method; HYSPLIT; Leptosphaeria biglobosa; Long distance transport; Oilseed rape; Real-time PCR