Competition Between Fusarium pseudograminearum and Cochliobolus sativus Observed in Field and Greenhouse Studies

Abstract

Among root pathogens, one of the most documented antagonisms is the suppression of Cochliobolus sativus by Fusarium (roseum) species. Unfortunately, previous studies involved single isolates of each pathogen and thus, provided no indication of the spectrum of responses that occur across the respective species. To investigate the variability in interactions between Cochliobolus sativus and Fusarium pseudograminearum, field and greenhouse trials were conducted that included monitoring of spring wheat plant health and monitoring of pathogen populations via quantitative real-time polymerase chain reaction. The interactions between two isolates of C. sativus and four isolates of F. pseudograminearum were explored in three geographically distinct wheat fields. To complement field trials and to limit potentially confounding environmental variables that are often associated with field studies, greenhouse trials were performed that investigated the interactions among and between three isolates of C. sativus and four isolates of F. pseudograminearum. Across field locations, C. sativus isolate Cs2344 consistently and significantly reduced Fusarium populations by an average of 20.1%. Similarly, F. pseudograminearum isolate Fp2228 consistently and significantly reduced C. sativus field populations by an average of 30.9%. No interaction was detected in the field between pathogen species with regards to disease or crop losses. Greenhouse results confirmed a powerful (>99%), broadly effective suppression of Fusarium populations by isolate Cs2344. Among greenhouse trials, additional isolate-isolate interactions were observed affecting Fusarium populations. Due to lower C. sativus population sizes in greenhouse trials, significant Fusarium suppression of C. sativus was only detected in one isolate-isolate interaction. This study is the first to demonstrate suppression of Fusarium spp. by C. sativus in field and greenhouse settings. These findings also reveal a complex competitive interaction between these two pathogen species that was previously unknown.

Interactions between Magnaporthiopsis maydis and Macrophomina phaseolina, the Causes of Wilt Diseases in Maize and Cotton

“…Antagonistic interactions between phytoparasitic fungi have previously been reported in other host-pathogen species pairs [23], as detailed in the Introduction. In many of those studies, the molecular DNA tracing proved to be an essential research tool [25,27,42]. An example that is very similar to the current research is one of the most documented antagonisms among root pathogens, the suppression of Cochliobolus sativus by Fusarium (roseum) species [42].…”

“…In many of those studies, the molecular DNA tracing proved to be an essential research tool [25,27,42]. An example that is very similar to the current research is one of the most documented antagonisms among root pathogens, the suppression of Cochliobolus sativus by Fusarium (roseum) species [42]. In this recent study, a field trial was conducted that included the monitoring of spring wheat plant health and pathogen populations using qPCR.…”

Resistant risk and resistance‐related point mutation in SdhC1 of pydiflumetofen in Fusarium pseudograminearum

“…Various factors bring about increases in FCR disease severity, including no-till adoption, limited numbers of resistant cultivars, large numbers of pathogens accumulated in the soil, severe salinization of soil, and drought stress in particular. 25,26 Pydiflumetofen, a new-generation SDHI, showed excellent performance in controlling FHB caused by F. graminearum and F. asiaticum. 16,17 Therefore, it may be a candidate for FCR control given that no fungicides have been registered for the control of FCR in China.…”

“…The symptoms of the disease develop imperceptibly, together with common root rot and wheat take‐all in the whole growth period in the field. Various factors bring about increases in FCR disease severity, including no‐till adoption, limited numbers of resistant cultivars, large numbers of pathogens accumulated in the soil, severe salinization of soil, and drought stress in particular 25,26 . Pydiflumetofen, a new‐generation SDHI, showed excellent performance in controlling FHB caused by F. graminearum and F. asiaticum 16,17 .…”

Pathogenic Interactions between Macrophomina phaseolina and Magnaporthiopsis maydis in Mutually Infected Cotton Sprouts

“…Similar antagonistic interactions have been previously reported in phytoparasitic fungi pairs of other plants. One example is the suppression of Cochliobolus sativus by the Fusarium (roseum) species [40]. In this case, C. sativus and F. pseudograminearum consistently and significantly reduced one another under field conditions.…”