Is Fusarium meridionale more adapted as Gibberella Ear and Stalk Rot pathogen of maize than F. graminearum? Comparative epidemiology and toxigenicity
type: CreativeWork
description: Gibberella ear (GER) and stalk rot (GSR) diseases of maize in Brazil are caused mainly by Fusarium meridionale, a species belonging to the Fusarium graminearum species complex (FGSC). Another species within this complex, F. graminearum, is second in importance on maize but is the main species causing Fusarium Head Blight disease of wheat in Brazil. This species is also the predominant cause of GER and GSR in North America, where F. meridionale has never been found. One hypothesis for the observed shift in dominance on different hosts where these species co-occur is that F. meridionale is more fit and adapted on maize than F. graminearum, and vice-versa. We undertook a thorough comparative analysis of pathogenic and saprophytic fitness- related traits using a collection of strains representative of the two species and hosts of origin in order to test this hypothesis. First, four field trials were conducted at different locations and hybrids to compare the aggressiveness (measure of GER severity) of two F. meridionale and two F. graminearum strains, all isolated from maize, inoculated singly or sequentially and alternately at the silking stage. Overall, GER severity was highest in plants inoculated with F. meridionale alone (52.1%); intermediate when inoculation with F. meridionale was followed by F. graminearum (Fmer⇾Fgra, 40.3%) or when F. graminearum was followed by F. meridionale (Fgra⇾Fmer, 38.3%); and lowest in plants inoculated with F. graminearum alone (23.8%). Only nivalenol (NIV) mycotoxin was detected in kernels from F. meridionale inoculations, and deoxynivalenol (DON) was the only mycotoxin found in F. graminearum inoculations. Approximately equal amounts of NIV and DON (1.2:1), along with zearalenone (ZON), were found in Fmer⇾Fgra, but only NIV could be detected in the Fgra⇾Fmer treatments. These results suggested that F. meridionale was more aggressive to maize than F. graminearum. However, this experiment included only a small number of isolates and so…
abstract: Gibberella ear (GER) and stalk rot (GSR) diseases of maize in Brazil are caused mainly by Fusarium meridionale, a species belonging to the Fusarium graminearum species complex (FGSC). Another species within this complex, F. graminearum, is second in importance on maize but is the main species causing Fusarium Head Blight disease of wheat in Brazil. This species is also the predominant cause of GER and GSR in North America, where F. meridionale has never been found. One hypothesis for the observed shift in dominance on different hosts where these species co-occur is that F. meridionale is more fit and adapted on maize than F. graminearum, and vice-versa. We undertook a thorough comparative analysis of pathogenic and saprophytic fitness- related traits using a collection of strains representative of the two species and hosts of origin in order to test this hypothesis. First, four field trials were conducted at different locations and hybrids to compare the aggressiveness (measure of GER severity) of two F. meridionale and two F. graminearum strains, all isolated from maize, inoculated singly or sequentially and alternately at the silking stage. Overall, GER severity was highest in plants inoculated with F. meridionale alone (52.1%); intermediate when inoculation with F. meridionale was followed by F. graminearum (Fmer⇾Fgra, 40.3%) or when F. graminearum was followed by F. meridionale (Fgra⇾Fmer, 38.3%); and lowest in plants inoculated with F. graminearum alone (23.8%). Only nivalenol (NIV) mycotoxin was detected in kernels from F. meridionale inoculations, and deoxynivalenol (DON) was the only mycotoxin found in F. graminearum inoculations. Approximately equal amounts of NIV and DON (1.2:1), along with zearalenone (ZON), were found in Fmer⇾Fgra, but only NIV could be detected in the Fgra⇾Fmer treatments. These results suggested that F. meridionale was more aggressive to maize than F. graminearum. However, this experiment included only a small number of isolates and so…
author: Machado, Franklin Jackson
language: eng
keywords: Plantas - Doenças e pragas, Micotoxinas, Fungos fitopatogênicos, Zea mays, Triticum aestivum, Gibberella zeae
date published: 2019-12-20
date modified: 2026-07-24T01:21:51Z
provider: Brazil UFV
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Universidade Federal de Viçosa