Identification and differentiation of mycorrhizal isolates of black alder by sequence analysis of the ITS region

Twenty isolates of black alder ectomycorrhizas were characterized on the ba sis of internal transcribed spacer (ITS) DNA sequences and colony morpholog y in pure culture. The isolates were obtained from individual, surface-ster ilized mycorrhizas morphologically identified as the mycorrhizal type "Alni rhiza cystidiobrunnea". Analysis of ITS sequences allowed differentiation i nto four groups; three were closely related? while one isolate (BEh-Uw1) wa s separated by high sequence dissimilarity within the ITS1 and ITS2. spacer regions. Culture morphology was not a satisfactory differentiating feature for these four groups. An Ncbi GenBank DNA database search revealed that i solates within the three closely related ITS groups displayed high homology to ITS sequences of Tomentella sublilacina and Thelephora terrestris, wher eas BEh-Uw1 had the highest sequence similarity to an ITS DNA sequence of a basidiomycete DNA isolated from bamboo leaves.