Weeds harbor Fusarium species that cause malformation disease of economically important trees in western Mexico

Authors: MONTOYA-MARTINEZ, AMELIA - Universidad Michoacana De San Nicolas De Hidalgo; O Donnell, Kerry; Busman, Mark; Vaughan, Martha; McCormick, Susan; SANTILLAN-MENDOZA, RICARDO - Universidad Michoacana De San Nicolas De Hidalgo; PINEDA-VACA, DANIELA - Universidad Michoacana De San Nicolas De Hidalgo; CLAPES-GARDUNO, LYANA - Universidad Michoacana De San Nicolas De Hidalgo; FERNANDEZ-PAVIA, SYLVIA - Universidad Michoacana De San Nicolas De Hidalgo; PLOETZ, RANDY - University Of Florida; BENITEZ-MALVIDO, JULIETA - Universidad Nacianal Autonoma De Mexico; MONTERO-CASTRO, JUAN - Universidad Michoacana De San Nicolas De Hidalgo; RODRIGUEZ-ALVARADO, GERARDO - Universidad Michoacana De San Nicolas De Hidalgo

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/22/2021
Publication Date: 2/5/2022
Citation: Montoya-Martinez, A.C., O'Donnell, K., Busman, M., Vaughan, M.M., McCormick, S.P., Santillan-Mendoza, R., Pineda-Vaca, D., Clapes-Garduno, L., Fernandez-Pavia, S.P., Ploetz, R.C., Benitez-Malvido, J., Montero-Castro, J.C., Rodriguez-Alvarado, G. 2022. Weeds harbor Fusarium species that cause malformation disease of economically important trees in western Mexico. Plant Disease. 106(2):612-622. https://doi.org/10.1094/PDIS-06-21-1339-RE.
DOI: https://doi.org/10.1094/PDIS-06-21-1339-RE

Interpretive Summary: During pathogen surveys of economically important trees in the states of Guerrero and Michoacán in the central western region of Mexico, mango malformation disease (MMD) was discovered in several orchards. In prior work, Fusarium pseudocircinatum and F. mexicanum were found to be the etiological agents of this disease in these states. However, the role that weeds serve as reservoirs of these pathogens in the disease cycle is unknown. The objectives of this research were to recover Fusarium isolates from understory vegetation in mango orchards with MMD and identify them using DNA sequence data. Additional objectives of this study were to compare Fusarium isolates recovered from weeds and mango trees in the same orchards and to assess their potential to produce toxins. This is the first report of weeds harboring Fusarium species that cause MMD in Mexico. Results of this study should prove valuable for further study of the epidemiological role of weeds in MMD and help manage the disease. This research will aid plant disease specialists, quarantine officials, and plant breeders in their efforts to develop robust disease control strategies and mango cultivars with broad based resistance to MMD.

Technical Abstract: Mango malformation disease (MMD) caused by Fusarium spp. is an important limiting factor in most production areas worldwide. Fusarium mexicanum and F. pseudocircinatum have been reported as causing MMD in Mexico. These two pathogens also cause a similar disease in Swietenia macrophylla (big-leaf mahogany malformation disease or BLMMD) in central western Mexico, while F. pseudocircinatum was recently reported as causing malformation disease in Tabebuia rosea (rosy trumpet) in the same region. These studies suggest that additional plant species, including weeds, might be hosts of these pathogens. The role that weed hosts might have in the disease cycle is unknown. The objectives of this work were to recover Fusarium isolates from understory vegetation in mango orchards with MMD, identify the Fusarium isolates using DNA sequence data, and determine if F. mexicanum is capable of inducing disease in the weedy legume Senna uniflora (oneleaf senna). Additional objectives in this work were to compare Fusarium isolates recovered from weeds and mango trees in the same orchards, by characterizing their phylogenetic relationships, assessing in vitro production of mycotoxins, and identifying their mating type idiomorph. A total of 59 Fusarium isolates from five species complexes were recovered from apical and lateral buds from four weed species. Two of the species within the F. fujikuroi species complex are known to cause MMD in Mexico. Trichothecene production was detected in five isolates, including F. sulawense and F. irregulare in the F. incarnatum-equiseti species complex and F. boothii in the F. sambucinum species complex. Both mating types were present among mango and weed isolates. This is the first report of herbaceous hosts harboring Fusarium species that cause mango malformation in Mexico. The information provided should prove valuable for further study of the epidemiological role of weeds in MMD, and help manage the disease.