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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Plant Genetic Resources and Disease Research » Research » Publications at this Location » Publication #409589
Research Project: Crop Health and Genetic Improvement of Sub-Tropical and Tropical Crops in the Pacific

Location: Tropical Plant Genetic Resources and Disease Research

Title: Survey of potential fungal antagonists of coffee leaf rust (Hemileia vastatrix) on Coffea arabica in Hawai‘i, USA

Author
item Luiz, Blaine
item Sugiyama, Lionel
item Johnston, Colleen
item Keith, Lisa

Submitted to: Brazilian Journal of Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/8/2024
Publication Date: 5/14/2024
Citation: Luiz, B.C., Sugiyama, L.S., Brill, E., Keith, L.M. 2024. Survey of potential fungal antagonists of coffee leaf rust (Hemileia vastatrix) on Coffea arabica in Hawai‘i, USA. Brazilian Journal of Microbiology. https://doi.org/10.1007/s42770-024-01304-2.
DOI: https://doi.org/10.1007/s42770-024-01304-2

Interpretive Summary: Coffee leaf rust (CLR), which is caused by the fungus Hemileia vastatrix, attacks the leaves of coffee trees and has caused billions of dollars of damage worldwide. CLR is extremely difficult to control. While conventional fungicides are used, a recent shift toward eco-friendly farming practices has occurred and new, effective, and sustainable strategies for CLR control are needed. This study isolated and identified the genera of potential fungal enemies of H. vastatrix from infected CLR lesions from coffee leaves on Hawai‘i Island, HI, USA. The potential use as a valuable tool to reduce disease severity is discussed.

Technical Abstract: Hemileia vastatrix, causal agent of coffee leaf rust (CLR), is an aggressive pathogen of coffee plants worldwide. Conventional fungicides have played a major role in the suppression of this disease, but a recent shift toward eco-friendly farming practices has occurred and additional novel, effective, and sustainable strategies for CLR control are needed. Naturally occurring fungal antagonists could be well-positioned to meet this demand; however, these fungi need to be isolated and tested for efficacy to identify organisms with potential. In this study, a survey of fungi associated with CLR lesions in three districts of Hawai‘i Island, HI, USA was conducted. Coffee leaves infected with CLR were collected from 22 locations and over 600 lesions co-infected with fungi were plated on ½ APDA and CTC 4T media. DNA was extracted from purified isolates and the internal transcribed spacer region (ITS) was sequenced and analyzed by BLASTn. In total, 194 isolates comprising 50 taxa were recovered. Several of the genera are known antagonists of Hemileia vastatrix or other plant pathogens, including Simplicillium, Akanthomyces, Cladosporium, Fusarium, and Clonostachys. The wide diversity of fungi associated with CLR lesions provide a wealth of possibilities for identifying potential CLR antagonists that could serve as a valuable tool for coffee farmers as part of an integrated pest management plan.