Effect of the Toxicogenic Ability of Fusarium graminearum on Physiological Quality of Soybean Seeds and Flours

PERUZZO, A.; PIOLI, R.N.

Soybeans: Cultivation, Nutritional Properties and Effects on Health

Nova Science Publishers, Inc.

Lugar: New York; Año: 2017; p. 119 - 151

Fusarium graminearum causes head blight and rot spikes in cereals, although it was isolated from Fabaceae, such as soybean, lentil, bean and pea. This pathogen causes losses in yield, seed quality and is able to produce mycotoxins. In fact, the wide range of Fusarium hosts, inoculum sources associated to crop residues and soils, and lack of effective control strategies, increased the worldwide distribution of these pathologies. Several seed techniques (X-ray analysis, electrical conductivity, topographic biochemical tetrazolium and standard germination tests) and the Enzyme-Linked Immunosorbent Assay are effective for diagnosing damages, physiological quality of seeds and detecting mycotoxins in flours. The objectives of this research were to evaluate the deoxynivalenol and zearalenone toxin transmission caused by several F. graminearum isolates, and their effect on seed viability and flour quality of soybean and wheat. The fungal collection was prior morphological and molecularly characterized to validate the taxonomic identity as belonging to F. graminearum Group 2. Isolates were obtained from diverse bio-ecological environments and hosts and showed high (80%) intraspecific similarity (morphologic and molecular) showing their plasticity and adaptative capability. The two inoculation methods used, in vitro and greenhouse conditions, at stem basal node and soybean infrutescence were, equally effective; and the F. graminearum-wheat interaction was included as positive control. Only zearalenone concentration registered in soybean flours overcame the values allowed by the European Union rules, whilst both toxins were excessive in wheat. As conclusions, this study allowed to detect some relationships: i) between mycotoxin production and both bioassays conditions (in vitro and in vivo), ii) mycotoxins and fungal pathogenicity, iii) zealarenone production and its transmission to soybean flour, and iv) the depressed effect on physiological quality of soybean seeds.