Evidence for host-specificity of culturable fungal root endophytes from the carnivorous plant Pinguicula vulgaris (Common Butterwort)

The unique mode of nutrition by carnivorous plants makes the facilitation of nutrient acquisition by mycorrhizal fungi seem unlikely. However, previously we have reported that the carnivorous plant Drosera rotundifolia can host at least eight species of fungal root endophyte. Although the function of these fungi remains unknown, their ubiquitous presence suggests that they may give plants a competitive advantage in both stressful and nutrient poor environments. The aim of this study was to examine the species of fungal endophyte colonising the roots of Pinguicula vulgaris and to compare them with the species isolated from D. rotundifolia found growing in the same location. Trichoderma spp. were isolated from every plant, whilst four other species were isolated once from single plants (Neonectria sp., Leohumicola spp., Cladosporium macrocarpum and Volutella ciliata). Although Trichoderma were isolated from both carnivorous plants, all of the other fungal endophytes were found colonising either P. vulgaris or D. rotundifolia. This observation may indicate a degree of host-specificity for these fungal species, despite the two host plants having very similar ecological strategies for living in a very nutrient poor and abiotically stressful environment.