Resumo

PECINA-QUINTERO, Víctor et al. Genetic diversity of ergot (Claviceps africana Frederickson, Mantle and de Milliano) from [Sorghum bicolor (L.) Moench.] in Mexico. Rev. mex. fitopatol [online]. 2007, vol.25, n.1, pp.43-47. ISSN 2007-8080.

This study was conduced in Rio Bravo, Tamaulipas, and Celaya, Guanajuato, Mexico, in which pathogenicity of two isolates of ergot (Claviceps africana) obtained from the same two locations, were evaluated on six hybrids and three male sterile sorghum lines. Also, a genetic analysis was performed in twelve isolates of the fungus using AFLPs markers. The analysis of variance indicated significant differences between isolates for pathogenicity (evaluated as the floral infection percentage in sorghum genotypes), differences between genotypes, locations, planting dates, and years. The genetic analysis showed a great genetic intrapopulation variation (60% genetic diversity) and the occurrence of different ergot genotypes; nevertheless, there was a high genetic similarity (> 94%) by the clonal character. In general, three groups of ergot genotypes are affecting sorghum in Mexico, one in the Bajio area (Guanajuato and Jalisco), another in Tamaulipas, and the third one in Sinaloa.

Palavras-chave : Polymorphisms; AFLP markers; sorghum; Sorghum bicolor.