P-534 - Sibling Rivalry: Investigating host and geographic distributions of Phytophthora palmivora and Phytophthora heterospora

Tuesday, August 5, 2025

10:15 AM - 11:00 AM HST

Location: Exhibit Hall 3

Presenting Author(s)

AF

Alexander Charles Fast

Graduate Research Assistant
University of Florida
Gainesville, Florida, United States

Author(s)

AR

Avril C. Rosano, n/a

Undergraduate Assistant Researcher
University of Florida
Gainesville, Florida, United States
MT

Miaoying Tian, PhD

Distinguished Professor
University of Georgia
Tifton, Georgia, United States
EG

Erica M. Goss, PhD

Professor
University of Florida, Department of Plant Pathology
Gainesville, Florida, United States

Abstract Text: Phytophthora palmivora is a plant-pathogenic oomycete with a cosmopolitan distribution and among the greatest host ranges in the genera, infecting over 160 plant genera in 60 families, causing hundreds of millions of dollars in loss in hosts such as cacao and African oil palm. Phytophthora heterospora, first described in 2021, is the most closely related species to P. palmivora and has been found causing the same disease symptoms on crops that P. palmivora infects, including olive, durian, Cattleya orchid and pomegranate. Little is known about the host and geographic distribution of P. heterospora in relation to P. palmivora. This study presents a multi-locus sequence typing (MLST) analysis of these species, utilizing a diverse collection of isolates from six continents and over 50 host species. Our MLST analysis using three house-keeping genes (ITS, Btub, and NADH) confirms additional hosts and countries with P. heterospora and uncovers its geographical and host distribution relative to P. palmivora. Importantly, our results reveal potential hybrids between P. palmivora and P. heterospora, suggesting a complex evolutionary interaction.