Abstract Detail

Mycology

Perez-Pazos, Eduardo [1], Certano, Amanda [2], Gagne, Joe [3], Lebeuf, Renée [4], Siegel, Noah [5], Nguyen, Nhu [6], Kennedy, Peter [3].

The slippery nature of ectomycorrhizal host specificity: Suillus fungi associated with novel pinoid (Picea) and a.

Suillus  is among the best-known examples of an ectomycorrhizal (ECM) fungal lineage that demonstrates a high degree of host specificity. Currently recognized host genera of  Suillus  include  Larix,  Pinus, and  Pseudotsuga, which all belong to the pinoid clade of the family Pinaceae. Intriguingly,  Suillus  sporocarps have been sporadically collected in forests in which known hosts from these genera are locally absent. To determine the capacity of  Suillus  to associate with alternative hosts in both the pinoid and abietoid clades of the Pinaceae, we examined the host associations of two  Suillus  species (S. punctatipes  and  S. glandulosus) through field-based root tip sampling and seedling bioassays. Root tip collections underneath  Suillus  sporocarps were molecularly identified (fungi: ITS, plant:  trnL) to assess the association with non-primary hosts. The bioassays contained both single- and two-species treatments, including a primary (Larix  or  Pseudotsuga) and a secondary (Picea,  Pinus, or  Abies) host. For the  S. punctatipes  bioassay, an additional treatment in which the primary host was removed after 8 months was included to assess the effect of primary host presence on longer-term ECM colonization. The field-based results confirmed that  Suillus  fungi were able to associate with  Abies  and  Tsugahosts, representing novel host genera for this genus. In the bioassays, colonization on the primary hosts was detected in both single- and two-species treatments, but no colonization was present when  Picea  and  Abies  hosts were grown alone. Removal of a primary host had no effect on percent ECM colonization, suggesting primary hosts are not necessary for sustaining  Suillus  colonization once they are successfully established on secondary hosts. Collectively, our results indicate that host specificity is more flexible in this genus than previously acknowledged and helps to explain the presence of  Suillus  in forests where recognized hosts are not present.

1 - University of Minnesota, Ecology Evolution and Behavior, 1479 Gortner Ave, Saint Paul, MN, 55108, USA
2 - University of Minnesota, Plant & Microbial Biology, 479 Gortner Ave., Saint Paul, MN, 55108, USA
3 - University of Minnesota, Plant & Microbial Biology, 1479 Gortner Ave, Saint Paul, MN, 55108, USA
4 - Cercle des mycologues de Lanaudière et de la Mauricie, Saint-Casimir, QC, Canada
5 - 32 Prospect Hill Rd, Royalston, MA, USA
6 - University of Hawai'i, Department of Tropical Plant & Soil Sciences, Mānoa, HI, USA

Keywords:
host specificity
mycorrhizal symbiosis
Pinaceae
Anomalous symbiosis
Mycology.

Presentation Type: Oral Paper
Session: MY3, Mycology: Fungus-Plant Interactions - Ectomycorrhizae and Orchid Mycorrhizae
Location: /
Date: Tuesday, July 20th, 2021
Time: 3:30 PM(EDT)
Number: MY3003
Abstract ID:971
Candidate for Awards:MSA Best Oral Presentation Award by a Graduate Student