Tracing seed to seedling transmission of the wheat blast pathogen <i>Magnaporthe oryzae</i> pathotype <i>Triticum</i>

Wheat blast caused by Magnaporthe oryzae pathotype Triticum (MoT), initially restricted to South America, is a global threat for wheat after spreading Asia in 2016 the introduction of contaminated seeds, raising question about transmission pathogen from seeds seedlings, process so far not well understood. We therefore studied relationship between seed infection and disease symptoms on seedlings adult plants. To accomplish this objective, we inoculated spikes cv. Apogee with transgenic isolate (MoT-DsRed, addition being resistant hygromycin). identified MoT-DsRed experiments using hygromycin resistance selection or observation DsRed fluorescence. The infected plants looked either apparently healthy shrivelled. evaluate transmission, two experimental designs were chosen (blotter test greenhouse) was recovered both. This revealed that MoT able colonize under ground. favourable conditions temperature humidity allowed high recovery rate shoots when grown artificial media. Around 42 days germination could be reisolated, indicating fungal progression, at time point, did proceed systemically/endophytically. hypothesize spike might occur via spore dispersal leaves rather than within plant. Because only successfully reisolated coats germinating symptoms, but also urgent attention needed minimize risks inadvertent inoculum.