6 %, nursery: 32.5 %), the second best represented order

was Dothideales for adult plants (asymptomatic: 15.7 %, esca-symptomatic: 15.1 %, nursery: 1.7 %), but Hypocreales for nursery plants (nursery: 26.8 %, asymptomatic: 4.6 %, esca-symptomatic: 3.8 %). Several orders were exclusively found in adult plants (Chaetothyriales, Calosphaeriales, Magnaporthales, Microascales, Agaricales, Corticiales, Hymenochaetales, Polyporales, and Russulales), whereas Ophiostomatales and Atheliales BMS-907351 clinical trial were exclusively present in nursery plants. Most of these orders were represented by singletons or doubletons totaling less than 5 % of the isolated fungi in each plant category. Exceptions were Chaetothyriales in adult plants (asymptomatic: 11.3 %, esca-symptomatic: 12.1 %) and Ophiostomatales in nursery plants (5.3 %). At the ordinal level, the shift in fungal groups from nursery to adult plants showed a considerable decrease of Hypocreales and a complete disappearance of Ophiostomatales. In contrast, Xylariales and particularly Dothideales and Capnodiales increased significantly with plant age. The principal buy GF120918 component analysis (PCA) of OTUs incidence data showed that the indicator species of the

fungal community of adult plants were highly similar while nursery plants hosted a very different mycota composition (Fig. 6). Fig. 6 Biplot of the principal component analyses showing the relative contribution of the plant samples to the main axes (nursery, esca-symptomatic and asymptomatic). The relative contributions of the fungal species are shown in black. The community composition was assessed based on species occurrence (presence-absence scoring) in each plant type Discussion To investigate the shift toward pathogenicity of the fungi generally assumed to generate the esca disease symptoms, we compared the fungal communities respectively associated with wood of asymptomatic and esca-symptomatic plants in a single vineyard. As endophyte assemblages of plants are known to vary between sites (Arnold et al. 2003), we limited our experiment to a single adult vineyard. To determine if the esca-associated fungi were transmitted through the grafting process we also analyzed

the fungal community associated with nursery plants that were not hot water treated, Fenbendazole and grafted with material sampled in the same vineyard and on the identical rootstock as the adult plants. The fungal biodiversity (158 OTUs—Online Resource 2) was estimated using direct identification and comparison of ITS sequences with those in GenBank. Using GenBank to identify some genera to species level must be treated with caution unless the sequence is derived from an extype strain (Cai et al. 2011a,b; Ko Ko et al. 2011; Maharachchikumbura et al. 2011, Manamgoda et al. 2011; Tempesta et al. 2011; Udayanga et al. 2011; Wikee et al. 2011; Yang et al. 2011). We adopted a 99 % sequence BLAST similarity threshold to determine species names (Gazis et al.