| dc.description.abstract | The Ascomycota form the largest phylum in the fungal kingdom and show a wide diversity of lifestyles, some involving beneficial or harmful associations with plants. Distinguishing between fungal endophytes – species which live asymptomatically in plant tissues – and plant pathogens is of major significance to economic and ecological issues relating to plant health. Evolutionary genomics methods can provide insight into the genetic determinants of these lifestyles, and collections can act as an invaluable source of material to enable such analyses. As endophytes are comparatively poorly studied, comparing plant associated lifestyles in the Ascomycota first requires novel endophyte discovery. In this thesis, I have demonstrated the unexplored promise of Kew’s Millennium Seed Bank for isolating viable fungal endophytes and, in the process, highlighted the potential issues of overlooking the seed microbiome in the seed banking practice. I then performed whole genome sequencing, assembly and annotation of novel endophytic Fusarium strains for a case-study exploring lifestyle evolution in the genus. The distribution of lifestyles across the phylogeny; similarity of gene repertoires; and patterns of codon optimisation suggested that Fusarium taxa have a shared capacity for pathogenicity/endophytism. Exploring to what extent these results are common to different lineages of the Ascomycota requires the generation of new genomic resources for endophytes at large. Consequently, I sequenced, assembled and annotated genomes for a further 15 endophyte strains from CABI’s collections, which spanned 8 families and 5 orders and additionally represent the first assembly for the genus and/or species for 7 of the strains. Together, this thesis demonstrates the value of existing plant and fungal collections for producing material and data to explore the pathogenic-mutualistic spectrum in plant associated ascomycetes. | en_US |
