The diversity of endophytic fungi in the above-ground tissue of two Lycopodium species in Poland

Endophytes are a large and diverse group of fungi that colonize healthy plant tissues without causing any symptoms. The majority of studies have focused on angiosperm and conifer hosts and few have examined the endophytes of lycophytes. In the present study, we characterized culturable endophytic fungi in two closely related Lycopodium species (L. annotinum and L. clavatum) from pine, beech, oak and spruce forests across Poland. More than 400 strains were isolated but only 18 Ascomycete species were identified. Members of the Dothideomycetes dominated the fungal endophyte communities in Lycopodium. The most abundant taxa cultured were Phoma brasiliensis (from L. clavatum) and Paraconiothyrium lycopodinum (from L. annotinum). Five taxa were isolated exclusively from L. annotinum, but only two of them (Paraconiothyrium lycopodinum and Mycosphaerella sp.) were relatively abundant. Two taxa were only found in L. clavatum, namely: Stagonospora pseudovitensis and an unidentified Dothideomycete. The taxon assigned as Ascomycota 2 (SH219457.06FU) was isolated only from strobili of both host species. Direct PCR and cloning from L. annotinum shoots revealed a substantially greater endophyte richness compared with the results from culturing.