Background/Objective.

In the roselle (Hibiscus sabdariffa) producing area of the state of Guerrero, Mexico, plantations with a high incidence of calyx blight were detected. The aim of this study was to know the causal agent of this disease.

Materials and Methods.

Calyces with and without symptoms of the “Criolla de Guerrero”, “Sudán” and “China Negra” cultivars were gathered from the municipal areas of Ayutla and Tecoanapa, Guerrero. Out of the calyces with symptoms, different fungal strains were isolated, out of which two were selected to perform pathogenicity tests under greenhouse conditions and identified with the amplification and sequencing of the elongation factor -1α (EF-1α) with the primers EF1-728F/EF1-986R.

Results and discussion.

The sequences obtained were compared with the ones in the NCBI and Fusarium MLST databases and they corresponded with the Fusarium incarnatum-equiseti (FIESC) 16 and 17 species complexes, currently known as Fusarium sulawesiensis and Fusarium pernambucanum, respectively. In the pathogenicity tests, the inoculated strains induced similar symptoms to those observed in the field. The FIESC complex has been proven to produce the mycotoxin trichothecene. Therefore, studies to determine the presence of this toxin in roselle are required, considering that its main use is the preparation of refreshing beverages, which may be a health risk.

Conclusion

. This is the first report of Fusarium sulawesiensis and Fusarium pernambucanum as causal agents of the roselle calyx blight in Mexico and in the world.

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