phylogenetic relationships of anamorphic form of some pleosporalean genera based on analysis of its rdna and rpb2

anamorphs of pleosporaceae are important plant pathogenic fungi. despite efforts to clarify phylogenetic relationships of this group there is still uncertainty about taxonomic position of some genera. therefor to elucidate relationships among anamorphic form of some pleosporalean taxa, the internal transcribed spacer (its) and rna polymerase second largest subunit (rpb2) of some members were determined and compared.phylogenetic analysis of both its and rpb2 regions which was performed by neighbor joining methods revealed that cochliobolus species were divided into two groups. that was the same and in congruent with previous investigations using other ribosomal regions. it also showed that alternaria brassicicola and a.panax formed a close clade to some ulocladium species. the its couldn’t segregate small- spore alternaria species but rpb2 was appropriate for this purpose.