Pathogenicity of Bipolaris species associated with Southern corn leaf blight disease in Brazil

Abstract

The aim of the current study was to investigate the pathogenicity of Bipolaris species associated with southern corn leaf blight (SCLB) in Brazil. Fungi were isolated from leaves presenting SCLB symptoms. Morphological features were described when the cultures were grown in Potato dextrose agar (PDA) medium. The ITS and GAPDH regions were used for phylogenetic analyses. The pathogenicity of B. maydis isolates was assessed in four popcorn lines under controlled conditions. Two Bipolaris species among the collected isolates were capable of infecting corn, namely, B. maydis and B. gossypina. Previous studies reporting the infection of corn by B. gossypina were not found; therefore, the present study appears to be the first to report it. Pathological differences between isolates were observed, and there was a significant isolate x line interaction. Line L692 was susceptible in all tests, while Line L623 was resistant to three B. maydis isolates. The isolate CF/UENF 482 of B. gossypina did not generate symptoms in the tested popcorn lines. The B. maydis isolates CF/UENF 477 and CF/UENF 501 were the most virulent.