Diversity of the internal transcribed spacer of rDNA in morels

The internal transcribed spacer (ITS) of rDNA was analysed by PCR/RFLP in 6 6 strains belonging to 11 putative species of the Morchellaceae and 3 speci es of the Discinaceae. For certain taxa, in particular Morchella esculenta, Morchella conica, and Morchella elata, isolates from distant geographical origins were available. Nevertheless, no intraspecific variations of ITS le ngth and restriction was noted. All genera were separated and within Morche lla; four putative species could be clearly distinguished in the group of t he yellow morels (sectio adnatae). In contrast, no distinction could be obt ained between the compared taxa in the group of the black morels (sectio di stantes). Sequence analyses of the ITS were performed in one strain of seve n putative Morchella. The sequence comparison confirmed the distinctions wi thin the yellow morels and allowed us to separate one putative taxon from t he others in black morels. Only the 5,8 gene could be aligned in all sequen ced samples. The ITS1 and ITS2 sectors could only be aligned within the bla ck and yellow morels, respectively. The genetic and phylogenetic distances between black and yellow morels, respectively revealed by maximum parsimony and neighbour joining analyses, both confirm the great distance between th ese species groups and address the question of a separation in the genus Mo rchella.