The Cylindrocladium candelabrum species complex includes four distinct mating populations

Cylindrocladium, candelabrum-like isolates were collected from a wide varie ty of geographic locations and compared based on their morphology), sexual compatibility) and the nucleotide sequences of their rDNA ITS regions. All isolates included in this study mated to produce Calonectria teleomorphs wi th viable progeny. Four distinct mating po,populations were identified, eac h representing a genetically isolated, biallelic, heterothallic population. Several representative isolates of each mating population, reflecting geog raphic diversity, were chosen for sequence comparisons. The internal transc ribed spacer (ITS) regions 1 and 2 that flank the 5.8S rDNA gene, as well a s the gene itself, were sequenced and compared. All isolates representing t he same group yielded similar sequences, but small, consistent differences were found between the groups. Based on these results we recognise Calonect ria scoparia (anamorph Cylindrocladium candelabrum), and describe three new species, namely Calonectria pauciramosa (anamorph Cylindrocladium pauciram osum), Calonectria insularis (anamorph Cylindrocladium insularae) and Calon ectria mexicana (anamorph Cylindrocladium mexicanum).