Abstract Detail

Mycology

Romero-Jimenez, Maria-Jose [1], Leopold, Devin [2], Busby, Posy [1].

Taxonomic and functional diversity of foliar yeasts of Populus trichocarpa .

Communities of endophytic fungi can provide multiple services to their host by improving their growth, resistance to abiotic stress and protection against pathogens. In black cottonwood (Populus trichocarpa), common leaf fungi - like Trichoderma, Cladosporium, and Penicillium - can reduce leaf rust disease severity. However, yeasts are generally poorly studied in the phyllosphere and more remains to be understood about the role of yeast community diversity on host disease outcomes. The aim of this study is to characterize the taxonomic and functional diversity of culturable epiphytic and endophytic yeasts from the phyllosphere of P. trichocarpa. Leaves of wild populations of P. trichocarpa were collected from Idaho, Montana, Oregon, and Washington to isolate epiphytic and endophytic yeasts. Epiphytic yeasts were recovered from beating the leaves in sterile distilled water, and serial dilutions were plated in Yeast Peptone Dextrose (YPD) agar with antibiotics To culture endophytes, the leaves were washed, beaten in PBS with 0.15% Tween 20, and grounded with a sterile pestle. Serial dilutions were prepared and plated in YPD with antibiotics. Over 300 epiphytic and endophytic yeast-like cultures were isolated from P. trichocarpa. Ninety-six isolates representing different morphotypes were identified by sequencing the rRNA ITS and LSU regions. Seven isolates are unidentified Pezizomycotina that potentially have not been described and several cultures represent common genera including: Aureobasidium, Rhodotorula, Filobasidium, Pseudozyma, and Dothiora. However, little is known about the impact of these yeast communities on poplar leaf rust disease outcomes. We hypothesize that greater diversity in yeast communities confers greater protection against leaf rust disease. In a greenhouse inoculation experiment we will test the relationship between yeast community diversity and disease protection by first inoculating P. trichocarpa leaves with synthetic yeast communities characterized by varying levels of richness and diversity. Leaves will then be inoculated with Melampsora x columbiana, and scored for disease severity.

1 - Oregon State University, Botany and Plant Pathology, 4575 SW Research Way, Corvallis, OR, USA
2 - Jonah Ventures, CO

Keywords:
Mycology.

Presentation Type: Poster
Session: MYP2, Mycology Posters II
Location: Virtual/Virtual
Date: Tuesday, July 20th, 2021
Time: 5:00 PM(EDT)
Number: MYP2008
Abstract ID:1036
Candidate for Awards:MSA Best Poster Presentation Award by a Graduate Student