Culturable Endophyte Fungi of the Well-Conserved Coastal Dune Vegetation Located on the East Coast of the Korean Peninsula

Abstract

This study aimed to determine the diversity and distribution of endophytic fungi in coastal dune vegetation. Endophytic fungi promote plant growth and protect host plants from environmental stress and pathogens. Plants that have flourished as a result are critical for protecting coastal sand dunes from erosion. A total of 361 root-colonizing fungal endophytes were purely isolated from 24 halophyte species comprising all dune plant communities indigenous to a well-conserved coastal area based on morphological differences. Molecular identification and phylogeny using amplified ribosomal RNA sequences and internal transcribed spacer regions identified that the fungal isolates belong to seven classes and 39 genera. Penicillium (43.21%) was the most dominant genera, followed by Talaromyces (16.90%) and Aspergillus (11.91%). Furthermore, these genera present a wide host range. However, 16 other genera exhibited strong host specificity. When compared to other herbaceous or shrub host plant species, Talaromyces predominated as endophytes of the roots of the canopy-forming coastal windbreak tree Pinus thunbergii. Based on Margalef’s, Menhinick’s, Shannon’s, and Simpson’s diversity indices, the root-colonizing endophytes of P. thunbergii had higher morphological diversity. The endophyte fungi associated with five of the coastal plants studied are heretofore unreported. In fact, of all fungal genera characterized here, 13 genera (30%) have not been previously reported as marine fungal endophytes or coastal fungi. The foregoing results suggest that future coastal sand dune conservation studies should examine the biological resources of entire bioclusters and not merely the dominant plants or their endosymbionts.