Phylogenetic structure of the Sporopachydermia cereana species complex

A large number of isolates previously referred to as members of the 'Sporop achydermia cereana species complex' were examined by various DNA characteri zation methods, leading to the conclusion that the complex is in fact made up of 10 species, one of which contains three varieties. The sequences of t he internal transcribed spacer (ITS) region and the D1/D2 divergent domains of the large subunit rDNA were determined for representatives of each taxo n and specific primers based on differences in the ITS were designed for ra pid identification of five of the taxa. Whereas the data provide additional elements for the calibration of the ITS as a criterion for species delinea tion, the emerging pattern is that the ITS region does not function as well as the D1/D2 domains as an evolutionary clock. Some taxa appear to be spec ific for the geographical regions where they were isolated, and the distrib ution of many taxa is mutually exclusive.