Interactions with mycorrhizal fungi in two closely related hybridizing orchid species.

The nuclear ribosomal DNA was used to identify the orchid mycorrhizal fungi found in roots of Orchis xbivonae and its parental species O. anthropophora and O. italica. Polymerase chain reaction products were sequenced and identified using the expanded database. We determined that closely related Tulasnellaceae are mycorrhizal in the three orchid taxa, suggesting that the mycorrhizal partner does not impair hybrid survival. This study demonstrates that O. xbivonae displays few differences in comparison with its two parental species in identity of its associated mycorrhizal fungi, it is a short-term by-product of the hybridizing behavior of common pollinators, and thus it will not easily origin descendents with potential new genetic combinations and/or ecological preferences.