Molecular and pathogenic characterization of new species of Colletotrichum associated with soybean anthracnose

Abstract

Soybean (Glycine max) is widely used in human and animal food and is considered the most produced oilseed in the world. Soybean production can be affected by anthracnose, a fungal disease of complex etiology, caused by several species of Colletotrichum, being species belonging to the C. truncatum and C. orchidearum species complexes the most representative and distributed around the world. While studies related to C. truncatum have advanced in recent years, the understanding of the interaction between soybean and C. musicola, C. orchidearum, and C. sojae, three species belonging to the C. orchidearum species complex is still incipient. Previous studies indicated that the two complexes belong to two distinct lineages, which do not share candidate effector genes. Moreover, the two lineages acquired the capability to infect soybeans independently, emphasizing the importance of the correct identification of the species present in soybean fields for the correct management of the disease. In this context, the present project aims to (I) perform the identification of Colletotrichum spp. with cylindrical conidia collected in soybean-producing regions between 2012 and 2017, based on phylogenetic analyses; (II) verify whether there is intraspecific diversity among the species identified in (i); and (III) to select, based on the results obtained in (I) and (II) representative isolates of the C. orchidearum species complex to perform pathogenic characterization. It is expected to clarify the etiology of the causal agent of soybean anthracnose in the central-west region of Brazil. Understanding the phylogenetic and intraspecific variability of Colletotrichum spp. associated with soybean is essential for the application and improvement of management strategies, including chemical and genetic control of the disease.(AU)