Epicoccum sorghinum: A RISK THAT THREATENS THE SAFETY OF THE SORGHUM CROP IN OUR COUNTRY

COLMAN DÉBORA; HIPPERDINGER MARCELA; ACOSTA MARINA; GORTARI CECILIA; ASTORECA ANDREA

Congreso; XVII Congreso Argentino de Microbiología General; 2022

Sociedad Argentina de Microbiología General (SAMIGE)

Sorghum consumption has increased considerably in the last 10 years, becoming the fifth most important cereal worldwide. Its particular agronomic characteristics have led to an increase in cultivated area, since it can be incorporated into rotations and be beneficial for the soil, occupying a fundamental role in the new Argentine agro-industrial chain, and also gaining more and more relevance worldwide (Serna -Saldivar, 2016). However, the productivity of this crop is affected by various fungal diseases that cause large economic losses. Species belonging to the genera Alternaria, Epicoccum and Picularia are reported as the main fungal contaminants in sorghum grains, and recognized producers of tenuazonic acid (TeA), a mycotoxin that acts as a powerful inhibitor of protein biosynthesis, causing various pathologies in animals and humans (Griffin & Chu, 1983; Yekeler et al., 2001).The presence of Epicoccum sorghinum in sorghum grains from the humid Argentine Pampas has been reported more than a decade ago by González et al. (1997), but until now not enough attention has been paid to its presence in relation to TeA contamination in any substrate in our country, since its production is historically and worldwide associated with the Alternaria genus. Due to the above, the objectives of this work were a) to determine the incidence of tenuazonic acid in sorghum samples from the experimental station of the National Institute of Agricultural Technology (INTA) in Manfredi, Córdoba and b) to confirm by molecular identification the presence of E. sorghinum in said culture. The results showed that 100% of the sorghum samples were contaminated with TeA, with concentrations that varied from 327 to 3372 μg/Kg, inferring that the presence of this mycotoxin represents an economic and health problem for the productive sector of said crop in our country. A phylogenetic tree was made with the sequences obtained from the isolates analyzed and a grouping of them was observed together with different isolates of Epicoccum sorghinum reported throughout the world, which would confirm their previous morphological identification. This is the first study that provides a molecular approximation of the E. sorghinum isolates that reveals its presence in Argentina, and clearly confirms the wide genetic and phenotypic variability previously reported for this species in other countries.