Click on the cite to copy
-
Or Copy link
Article filters
Search Papers
Searches prior to 2023, No. 3. In the section Volumes 30 - 41 (2012 - 2023).
First report of Fusarium sulawesiensis (FIESC 16) and Fusarium pernambucanum (FIESC 17) as causal agents of blight in roselle (Hibiscus sabdariffa) calyces in Mexico
By Candelario Ortega Acosta, Daniel Leobardo Ochoa Martínez*, Santo Ángel Ortega Acosta, Javier Hernández Morales, Francisco Palemón Alberto
*Corresponding Author.
Received: 28/February/2025 – Published: 30/April/2025 – DOI: https://doi.org/10.18781/R.MEX.FIT.2502-1
Share
Abstract 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.
Keywords: Fungal complex, 1α elongation factor, Phylogeny, Tropical crops
Figure 1. Symptoms of calyx blight in the three roselle cultivars; it can be observed that the capsule is exposed due to the blighting of the calyces; A. “Criolla de Guerrero”. B. “China Negra”. C. “Sudán”. Asymptomatic calyces of the different cultivars; D. “Criolla de Guerrero”, E= “China Negra” and F= “Sudán”.
Figure 2. Morphological species of the Fusarium incarnatum-equiseti species complex. A-B = Colonies grown in PDA for one week at 28 °C. A = F. sulawesiensis isolate BOLCHIN. B = F. pernambucanum isolate BOLCRIO. C = Monophialids from the isolate BOLCHIN. D and E = Macroconidia with a foot-shaped F. sulawesiensis and F. pernambucanum basal cells, respectively. F and G = F. sulawesiensis and F. pernambucanum, chain chlamidospores, respectively.
Figure 3. Maximum likelihood (ML) tree, from the Fusarium incarnatum-equiseti species complex, from partial gene EF-1α. A similar topology was generated using Bayesian Inference (BI). Subsequent Bayesian probabilities (PP> 0.5) and the Bootstrap support values (BS> 50) are shown in the nodes (PP/BS). The sequences of this study are in bold. The scale bar indicates the number of expected changes per site. *F. sulawesiense currently recognized as F. sulawesiensis (Xia et al., 2019).
Figure 4. Pathogenicity tests in roselle calyces 12 days after artificial inoculation under greenhouse conditions. A= F. sulawesiensis isolate BOLCHIN. B= F. pernambucanum isolate BOLCRIO. C=Calyx in which only the basal part was injured with a sterile toothpick.
