Many cryptic species have recently been discovered in fungi, especially in fungal plant pathogens. Cryptic fungal species co-occurring in sympatry may occupy slightly different ecological niches, for example infecting the same crop plant but specialized on different organs or having different phenologies. Identifying cryptic species in fungal pathogens of crops and determining their ecological specialization is therefore crucial for disease management. Here we addressed this question in the ascomycete Botrytis cinerea, the agent of grey mold on a wide range of plants. On grape, B. cinerea causes severe damages but is also responsible for noble rot used for processing sweet wines. We used microsatellite genotyping and clustering methods to elucidate whether isolates sampled on grey mold vs. noble rot symptoms in three French regions belong to genetically differentiated populations. The inferred population structure matched geography rather than the type of symptom. Noble rot symptoms therefore do not seem caused by a specific B. cinerea population but instead seem to depend essentially on microclimatic conditions, which has applied consequences for the production of sweet wines.

Microsatellite genotyping of Botrytis cinerea grey mold and noble rot populations in FranceMicrosatellite genotyping using 8 markers. Populations of B. cinerea collected in the field, in 3 wine-producing French regions, from grey mold and nobel rot symptoms. Data are given in allele size in bp (haploid data). 0 indicate missing values.PGPN2011.csv