Emended descriptions of Tilletiopsis washingtonensis, Tilletiopsis cremea and Tilletiopsis lilacina

For species discrimination, DNA relatedness, nuclear DNA (nDNA) base compos itions and internal transcribed spacer (ITS) regions were studied in strain s of the 'washingtonensis group' consisting of the type strains of Tilletio psis washingtonensis, Tilletiopsis cremea and Tilletiopsis lilacina as well s as nine strains previously identified as any one of the three species. T. washingtonensis is the neotype of the genus Tilletiopsis while T, cremea a nd T. lilacina are currently recognized as conspecific with T. washingtonen sis. The G+C content of the DNA of the strains examined in this study was 6 6-68 mol%. The type strains of T. washingtonensis. T. cremea and T. lilacin a were clearly discriminated on the basis of DNA complementarity. These gen ospecies should be treated as species. Moreover, an unrooted dendrogram con structed from ITs nucleotide sequences showed that the 'washingtonensis gro up' was divided into three clusters, corresponding to the three species T. washingtonensis, T. cremea and T.lilacina, respectively. The species descri ptions of T. washingtonensis, T.cremea and T. lilacina are emended accordin gly.