Abstract Detail

Mycology

Ke, Yi-Hong [1], Bazzicalupo, Anna [2], Branco, Sara [3], Nguyen, Nhu [4], Ruytinx, Joske [5], Vilgalys, Rytas [6].

Global introduction patterns of the pine ectomycorrhizal fungus Suillus luteus.

Global afforestation efforts have been accompanied by the widespread co-introduction of many ectomycorrhizal fungi (EMF) well beyond their original native ranges. One of the most successful EMF colonizing exotic pine forests is the European slippery jack Suillus luteus. As a model for study of fungal natural history and mycorrhizal symbiosis, the widespread, highly replicated, and recent (<150 yrs) global introduction of S. luteus with pines to novel and isolated geographic regions provide an excellent opportunity to test basic hypotheses about fungal population genomics as well as identifying its parental population and sources of introduction. We investigated the S. luteus global introduction patterns by analyzing whole genomes from 153 S. luteus fruiting bodies and cultures obtained from Asia, North America, South America, Oceania and Europe. Phylogenomic analysis suggests that the introduced populations are all derived from Central Europe; Northern Europe, Asia and native Northern America populations belong to separate lineages. Demographic models and negative Tajima’s D suggest ancient expansion of Central Europe population, consistent with Holocene post-glacial expansion. In contrast, demographic models and positive Tajima’s D in introduced populations imply that they have each undergone recent genetic bottlenecks. Joint sample site spectrum frequency analyses implemented in momi2 revealed the history of all introduced populations conforms best with a single divergent event followed by population expansion, except for the Australian population for which a second migration wave is suggested. To solve the detailed divergent history of Australia-New Zealand clade, demographic models with independent and sequential introduction were compared. The sequential introduction from New Zealand to Australia always has lower AIC than independent introduction or the opposite order of introduction regardless the existence of population growth or ghost population. Population genomics provide a first insight into the complex history of co-invasion of EMF with their pine hosts across the southern hemisphere. Additional functional studies will be needed to understand the adaptations and the evolutionary trajectory of EMF introductions.

1 - Duke University, Biology, 130 Science Dr, Biological Science Building, Durham, NC, 27705, United States
2 - University of British Columbia, Zoology
3 - University of Colorado
4 - University of Hawaii, Mānoa, USA
5 - Vrije Universiteit Brussel, Brussel, Belgium
6 - Duke University, Biology

Keywords:
Ectomycorrhizal fungi
Suillus luteus
Population Genetics
Introduction
demographic model
Mycology.

Presentation Type: Oral Paper
Session: MY3, Mycology: Fungus-Plant Interactions - Ectomycorrhizae and Orchid Mycorrhizae
Location: /
Date: Tuesday, July 20th, 2021
Time: 3:15 PM(EDT)
Number: MY3002
Abstract ID:798
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student