Approaches in the Management of Fusarium Head Blight of Wheat in Argentina

PALAZZINI, J.M.; YERKOVICH N. ; PALACIOS, S; RONCALLO, PABLO; CANTORO, RENATA; ECHENIQUE, VIVIANA; TORRES A.M; MARÍA L. RAMIREZ; KARLOVSKY P.; CHULZE, S.N.

Ghent

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

Mycokey Horizont 2020- Ghent University

Abstract: Fusarium Head Blight (FHB) is a devastating disease that causes extensive yield and quality losses to wheat, barley and other small cereal grains in humid and semi-humid region of the world. Members within the Fusarium graminearum species complex are the main pathogens associated with the disease, being F. graminearum sensu stricto the main pathogen isolated in Argentina.Chemical treatments, crop rotation, breeding for resistance and tillage practices are among the main strategies to control the disease. The application of antagonists and other chemicals such as chitosan are additional strategies to be used as a part of an integrated pest management. The aims of thisstudy were: to evaluate the control effect of Bacillus velezensis RC218, Streptomyces albidoflavus RC 87B, chitosan and a combination of them on FHB disease incidence and severity on durum wheat under field conditions; to evaluate the effect of Bacillus velezensis RC218 (Bvel), F. graminearum (Fgram)and their interaction on the induction of salicylic acid (SA) and jasmonic acid (JA) at different period times under greenhouse conditions ; to carry out a survey of new potential biocontrol agents against F. graminearum and the evaluation of them under in vitro and greenhouse conditions. Biocontrol atfield level showed effectiveness of the two biological control agents and chitosan in reducing both FHB disease incidence (29.5?63% reduction) and severity (25?50% reduction). Under greenhouse conditions,the phytohormone analysis showed that the production of JA was induced after F graminearum inoculation at 48 and 72 h, meanwhile JA levels were reduced in the co-inoculated treatment. No differences in JA or SA induction were observed between the B. velezensis treatment and the control. In the spikes inoculated with F. graminearum, SA production was early induced (12 h) asit was shown for initial FHB basal resistance; meanwhile the late induction of JA reveals a defense state against the hemibiotrophic pathogen F. graminearum. New bacterial strains were isolated from wheat soil samples and evaluated under in vitro conditions through an index of dominance assay as antagonist of F. graminearum. A total of eight strains were selected to evaluate the ability to control FHB under greenhouse conditions. Three out of eight strains evaluated were able to significantly reduce FHB severity under greenhouse conditions by up to 63%. The present work has received funding by the European Union?s Horizon 2020 Research and innovation programme under Grant Agreement No. 678781 (MycoKey).