Genetic diversity of root-associated fungal endophytes from Calluna vulgaris at contrasting field sites

A total of 107 putative ericoid mycorrhizal endophytes were isolated from h air roots of Calluna vulgaris from two abandoned arsenic/copper mine sites and a natural heathland site in southwest England. The endophytes were init ially grouped as 14 RFLP types, based on the results of ITS-RFLP analysis u sing the restriction endonucleases Hinf I, Rsa I and Hae III. ITS sequences were obtained for representative isolates from each RFLP type and compared phylogenetically with sequences for known ericoid mycorrhizal endophytes a nd selected ascomycetes. The majority of endophyte isolates (62-92 %) from each site were identified as Hymenoscyphus ericae, but a number of other le ss common mycorrhizal RFLP types were also identified, all of which appear to have strong affinities with the order Leotiales. None of the less common RFLP types was isolated from C. vulgaris at more than one field site. Neig hbour-joining analysis indicated similarities between the endophytes from C . vulgaris and mycorrhizal endophytes isolated from other Ericaceae and Epa cridaceae hosts in North America and Australia.