ABSTRACT
The corn (Zea mays L.) crop is subject to the occurrence of several diseases, including white spot, caused by Pantoea ananatis. Recently, this bacterium has been detected in corn seeds. Thus, the objectives of this study were: to evaluate culture media for P. ananatis detection, to detect this bacterium in eight corn seed genotypes, and to identify and biochemically and molecularly characterize the obtained bacterial isolates. To evaluate the culture media, the isolate of P. ananatis was cultivated in five culture media (523, NA, TSA, PA10 and PA20) with absence and presence of the fungicides cycloheximide and thiophanate-methyl, and three replicates each. The efficiency of each culture medium was determined based on the diameter of colonies and on the counting of colonies as CFU mL-1. To detect the bacterium in seeds, eight corn genotypes were evaluated. Seed extracts underwent serial dilution (10-1 to 10-2) and were grown in three culture media (523, NA and TSA) with three replicates for each dilution. The obtained isolates were biochemically, physiologically and molecularly characterized. The culture media TSA and 523 with addition of cycloheximide were effective in detecting P. ananatis. This bacterium was detected in five corn seed genotypes. TSA with addition of cycloheximide can be recommended for P. ananatis detection in corn seeds.
Keywords
Etiology; white spot; culture medium; Zea mays
