Morphological and molecular investigation of the parentage of Ophrys xcirclarium (O. lutea x O. tarentina), a new hybrid orchid from Italy

We amplified and sequenced internal transcribed spacer (ITS) region of the nuclear ribosomal repeat fromfungi in roots of Dactylorhiza sambucina (Orchidaceae) and used the extended database to identify the mycorrhizal fungi.We molecularly identified three ITS recovered from D. sambucina roots, one belonging to Rhizoctonia group, and twoto ascomycetes, for the first time in Orchidoidae. In many cases, two sequence types were found from the same orchidroot, providing that two taxa may be involved in mycorrhizal formation (multiple mycobiont colonization). Moreover, wedemonstrated that D. sambucina plants, irrespective of their colour polymorphism, possess roots containing several fungibelonging to both asco- and basidiomycetes.