Phylogenetic relationships in Leptographium based on morphological and molecular characters

Species of Leptographium Lagerberg & Melin are characterized by mononematou s conidiophores with dark stipes and conidiogenous apparatuses with complex series of branches. These fungi generally inhabit woody substrates, are as sociated with bark beetles (Coleoptera: Scolytidae) and cause blue-stain in conifers. Few phylogenetic studies have been conducted on Leptographium sp ecies, and those that have been undertaken have been focused on a small num ber of species. The objective of this study was to investigate the phylogen etic relationships among species in Leptographium based on partial DNA oper on sequences and to ascertain whether morphological characters are congruen t with DNA-based phylogeny. Morphological characters were analyzed and comp ared with results from DNA sequence analysis. Results indicate that there a re three groups within Leptographium based on DNA sequence analysis. There was, however, no congruence between these groups and those emerging from mo rphological characters. Data from this study strongly support the connectio n between Leptographium and Ophiostoma Sydow & Sydow. They also provide us with an objective means to confirm the identity of many Leptographium speci es that are difficult to distinguish based on morphological characters.