Distribution of fungi and tenuazonic acid in sorghum grains cultivated in different growing seasons and polyphasic study of Phoma spp. isolates.

Author(s)

Rodrigo Cardoso de Oliveira

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2017-04-13

Examining board members

Benedito Correa; José Ribamar dos Santos Ferreira Júnior; Sarah Santos Gonçalves; Kelly Ishida; Myrna Sabino

• Advisor: Benedito Correa

Abstract

The culture of sorghum in Brazil is widely used in animal feed. The aim of this study was evaluate the mycobiota and occurrence of tenuazonic acid in sorghum grains cultivated in two sowing periods. In addition, through a polyphasic approach, we characterized strains of Epicoccum sorghinum, as well as evaluated the ecophysiological of this species. E. sorghinum was the most prevalent fungus in sorghum grains. Tenuazonic acid was detected in all the samples, with higher levels in the grains grown in the summer crop. It was possible to verify considerable genetic variability in the strains of E. sorghinum, presenting as a complex of phylogenetic species. By evaluating the abiotic factors occurring in the field, as well as the access to an ecophysiology of E. sorghinum, it was possible to verify that hot and wet conditions are favorable for tenuazonic acid production. These results indicate the presence of toxic compounds in sorghum grains cultivated in Brazil, as well as contribute with information for crop management. (AU)

• FAPESP's process: 12/09570-1 - Distribution of fungi and mycotoxins and polyphasic study of Phoma spp. isolated from grains of sorghum during different sowing periods
• Grantee: Rodrigo Cardoso de Oliveira
• Support Opportunities: Scholarships in Brazil - Doctorate