Bacteria wilt is a problem affecting numerous trees in Guam. Under a grant from the United States Department of Agriculture (USDA), a University of Hawaiʻi at Mānoa assistant researcher and graduate students have helped to develop tests to rapidly distinguish the bacterial strain attacking the plants.
The USDA’s Priority Pest List for 2021 includes Ralstonia solanacearum race 3 biovar 2, a bacterium better known as a bacterial wilt. It infects through the roots and is deadly to plants, and is the subject of new grant funding for the University of Guam under the USDA’s Plant Protection Act.
Assisting with the characterization of Guam’s bacterial wilt strains are Mohammad Arif of UH Mānoa’s College of Tropical Agriculture and Human Resources Department of Plant and Environmental Protection Sciences and graduate students Sujan Paudel, Dario Arizala and Diksha Klair. Paudel and Shefali Dobhal recently developed rapid assay tests that can accurately and quickly distinguish the race 3 biovar 2 strain from the R. solanacearum species complex.
“With these diagnostic assays in hand, we can rapidly detect the bacteria directly from crude host tissue sap. We are now responsible for understanding how bacteria interact inside the host tissues, as well as mapping out endophytic communities associated with ironwood decline through microbiome studies,” said Arif.
“We’ll also study genetic variability among Ralstonia strains found associated with ironwood decline, and how this bacteria has evolved,” he added. “These objectives will enhance our understanding of this pathogen and disease, toward the development of effective disease-management strategies.”