Investigating Host Preference of Root Endophytes of Three European Tree Species, with a Focus on Members of the - Species Complex (PAC).

Host preference of root endophytes of the three European tree species of Norway spruce (), common ash (), and sycamore maple () were investigated in two forest stands near Zurich, Switzerland. The focus was placed on members of the s.l. (sensu lato)- species complex (PAC), as well as other dark septate endopyhtes (DSE). PAC species were identified based on 13 microsatellite loci. Eleven PAC species were found, with , being the most frequent. All but cryptic species 12 (CSP12) preferred Norway spruce as a host. Though very rare in general, CSP12 was most frequently isolated from maple roots. Regarding the abundant PAC species, and , the preference of spruce as a host was least pronounced in , as it was also often isolated from ash and maple. It is the first record of PAC found on common ash (). , a close relative of PAC, has frequently been isolated from ash. Various species of the ( spp.) have often been isolated, particularly from maple roots. By comparison, spp. ( spp.) was found to be abundant on all three hosts. exhibits a clear preference for spruce.