Approaches in the management of Fusarium head blight of wehat in Argentina

PALAZZINI J.M; YERKOVICH, N; PALACIOS, S; RONCALLO P; CANTORO R; ETCHENIQUE V; TORRES A.M.; RAMIREZ M.L.; KARLOVSKY, PETR; CHULZE , S.N

Ghent

Congreso; 1st MYCOKEY International Conference Global Mycotoxin Reduction in the Food and Feed Chain; 2017

Universidad de Ghent -Mycokey Project

Fusarium Head Blight (FHB) is adevastating disease that causes extensive yield and quality losses to wheat,barley and other small cereal grains in humid and semi-humid regions of theworld. Members within the Fusariumgraminearum species complex are the main pathogens associated with thedisease, being F. graminearum sensustricto the main pathogen isolated in Argentina. Chemical treatments, croprotation, breeding for resistance and tillage practices are among the mainstrategies to control the disease. The application of antagonists and otherchemicals such as chitosan are additional strategies to be used as a part of anintegrated pest management. The aims of this study were: -to evaluate thecontrol effect of Bacillus velezensis RC218,Streptomyces albidoflavus RC 87B,chitosan and a combination of them on FHB disease incidence and severity ondurum wheat under field conditions; -to evaluate the effect of Bacillus velezensis RC218 (Bvel), F. graminearum (Fgram) and theirinteraction on the induction of salicylic acid (SA) and jasmonic acid (JA) atdifferent period times under greenhouse conditions ; -to carry out a survey of newpotential biocontrol agents against  F. graminearum and the evaluation ofthem under in vitro and greenhouseconditions. Biocontrol at field level showed effectiveness of thetwo biological control agents and chitosan in reducing both FHB disease incidence(29.5-63 % reduction) and severity (25-50 % reduction). Under greenhouseconditions, the phytohormone analysis showed that the production of JAwas induced after F graminearuminoculation at 48 and 72 h, meanwhile JA levels were reduced in theco-inoculated treatment. No differences in JA or SA induction were observed betweenthe B. velezensis treatment and thecontrol. In the spikes inoculated with F.graminearum, SA production was early induced (12h) as it was shown forinitial FHB basal resistance; meanwhile the late induction of JA reveals adefense state against the hemibiotrophic pathogen F. graminearum. New bacterial strains were isolated from wheat soilsamples and evaluated under in vitro conditionsthrough an index of dominance assay as antagonist of F. graminearum. A total of eight strains were selected to evaluatethe ability to control FHB under greenhouse conditions. Three out of eightstrains evaluated were able to significantly reduce FHB severity undergreenhouse conditions by up to 63 %.The present work has received funding by theEuropean Union?s Horizon2020 Research and innovation programme under GrantAgreement No.678781 (MycoKey).