Solid substrate bioassay to evaluate the effect of Trichoderma and Clonostachys on the production of zearalenone by Fusarium species

Abstract

Fusarium head blight and maize ear rot are destructive diseases in various cereal production regions, leading to significant yield losses and to the contamination of cereal grain with Fusarium mycotoxins. The mycotoxin zearalenone belongs to the three most important mycotoxins produced by Fusarium species worldwide; moreover, its hormonal oestrogenic activity is higher than its toxicity. The compound also exhibits fungitoxic activity. Toxigenic Fusarium species sporulate on cereal crop residues and produce inoculum to infect the next crop. Reduction of mycotoxin production and pathogen sporulation may be influenced by saprophytic fungal antagonists. Selected Trichoderma and Clonostachys isolates in dual culture bioassays on rice reduced zearalenone, α-zearalenol and zearalenone sulphate production by two isolates of Fusarium graminearum Schwabe and two isolates of F. culmorum (W.G. Smith) Saccardo belonging to three different chemotypes, by over 97%. Two Trichoderma isolates reduced the amount of zearalenone produced by the same four Fusarium isolates by 5-83% in solid substrate bioassays, whereas several Clonostachys isolates reduced the amount of zearalenone by over 96%. Examination of the dynamics of zearalenone reduction showed that the reduction occurred at the fastest rate during the first four days of incubation. Selected non-toxigenic Trichoderma and Clonostachys isolates are candidates for biocontrol agents against toxigenic Fusarium pathogens of cereals and may be useful for decomposition of zearalenone in contaminated cereal grain and cereal products.

Clonostachys rosea BAFC3874 as a Sclerotinia sclerotiorum antagonist: mechanisms involved and potential as a biocontrol agent

“…2006; Zafari et al. 2008; Gromadzka et al. 2009) and are particularly useful in the case of soil‐borne fungi (Shoresh et al.…”

Survival of Fusarium graminearum, the causal agent of Fusarium head blight. A review

“…Already known biocontrol agents like T. atroviride and T. harzianum Rifai , or Clonostachys rosea (Link) Schroers, Samuels, Seifert and W. Gams (Gromadzka et al 2009) are among the possible candidates. It is also possible to screen species isolated from residues (Luongo et al 2005;Singh et al 2009).…”

Suppressive soil againstSclerotinia sclerotiorumas a source of potential biocontrol agents: selection and evaluation ofClonostachys roseaBAFC1646

“…The findings from our in vitro dual culture assays, an established method for initial evaluation of a microbial antagonist (Gromadzka et al, 2009;Whipps, 1987), provide strong evidence in support of C. rosea f. rosea BAFC1646 as a biocontrol agent. Although other strains of C. rosea have been shown to inhibit phytopathogens (Mejía et al, 2008;Whipps, 1987;Zazzerini & Tosi, 1985), it is noteworthy that our BAFC1646 strain showed an unusually high %RGI in all the conditions evaluated and against all strains of S. sclerotiorum evaluated.…”