An isolate morphologically and phylogenetically distinct from B otrytis cinerea obtained from withered grapes possibly represents a new species of B otrytis

Grapes kept after harvest for withering in drying fruit rooms ( fruttaio ) are highly susceptible to B otrytis cinerea infection. A taxonomically undefined isolate (B83) was identified during a survey of B . cinerea populations in these specific environments. This isolate yielded negative results in B . cinerea ‐specific PCR s and displayed a different colony morphology on potato dextrose agar. Based on this data, the isolate underwent a taxonomic investigation. Sequencing of the ITS –5·8S– ITS 2 region indicated that the isolate belongs to the Botrytis genus. IGS ‐ RFLP analysis revealed that B otrytis sp. B 83 was a different haplotype from genotypes of indigenous B . cinerea strains. Comparative sequence analysis of three housekeeping genes, G3 PDH , HSP 60 and RPB 2 , showed that the isolate constitutes a taxon related to B otrytis aclada , distant from B . cinerea . A phylogenetic tree built with NEP genes was in agreement with the combined tree built with G3 PDH , HSP 60 and RPB 2 sequences. Botrytis sp. B83 is morphologically similar to B . aclada . Conversely, its host range indicates that it is polyphagous like B . cinerea , despite its lower virulence. This study provides evidence for the existence of a new species of Botrytis . Nevertheless, the description of only a single isolate and the need for further information on genetic divergence, reproductive isolation and host preference, prevent the classification and formal description of a new taxon.