DNA Barcoding and Metabarcoding Approaches for the Assessment of Fungal Biodiversity within Successional Coastal Habitats

Abstract

Fungi are a fundamental component of Earth’s biosphere. They provide essential ecosystem services, such as nutrient recycling and determining soil health. Fungi also play a pivotal role in the evolution and present health of plants due their symbiotic relationships. The fungal kingdom is diverse with an estimated 2.2-3.8 million species worldwide within 18 extant phyla. Many fungi remain undiscovered due to the seasonality and visibility of fruiting bodies. Metabarcoding and bioinformatics provides a means to detect hidden taxon from multiple eDNA substrates (e.g. Soil, roots and air). The fungal communities within sand dune ecosystems are thought to differ in species diversity and underlying function within habitats undergoing vegetation succession. The main aim of this thesis is to uncover hidden fungal diversity while gaining insight into their functionality within dynamic sand dune environments by utilising an Ion torrent metabarcoding
approach. In addition, metabarcoding is used in combination with a novel AberTrap air sampler to determine its effectiveness as an ecological surveillance tool. Within Chapter two, root eDNA from Ammophila sp. and Leontodon sp. plants is sampled alongside soil eDNA from embryo and mobile dunes at Ynyslas, to determine differences below-ground fungal diversity through LSU metabarcoding in relation to the dune successional stage. Within chapter three, further exploration is undertaken within six geographically separated coastal dune systems of the differences in fungal communities and their functions within three distinct successional habitats found within each of the dune systems. Using soil eDNA metabarcoding of the ITS2 region to simultaneously detect differences in fungal and plant species within multiple successional habitats in relation to the underlying soil physiochemical properties. In chapter four, two aerobiological
metabarcoding investigations take place, firstly at Ynyslas using LSU and ITS2 metabarcoding within the dunes and secondly at Pwllpeiran uplands using ITS2 to determine the effectiveness of the AberTrap air sampler as an ecological surveillance tool by running the AberTrap at different speeds to capture air spora of different sizes. Overall it is demonstrated that the varying eDNA metabarcoding approaches can be used to detect a diversity fungal and plant organisms from substrates such as soil, plants and air. Soil eDNA if used at appropriate sample scales gives an in-depth ecological snapshot into the diversity and ecological functions of successional fungal communities. Root eDNA provides
an insight into the symbiotic relationships between plant and fungi. Air eDNA, aerobiology and the use of the AberTrap air sampler can effectively be used to gather data on air spora phenology. This thesis deploys eDNA metabarcoding to advance our understanding of fungal ecology within successional habitats by providing evidence of the diversity and functionality of fungi inhabiting ecosystems within coastal sand dunes and beyond

Date of Award	2023
Original language	English
Awarding Institution	Aberystwyth University
Supervisor	Gareth Griffith (Supervisor) & Elizabeth M. Wilberforce (Supervisor)