Relations among sorghum ergot isolates from the Americas, Africa, India and Australia
Sorghum ergot (or sugary disease of sorghum) was initially restricted to Asia and Africa but it recently spread to the Americas and Australia. Three species of fungi are associated with the disease: Claviceps sorghi in India, C. sorghicola in Japan and C. africana (EPPO Alert List) in all countries where the disease is observed. C. africana is the species that is currently spreading. The relations existing among sorghum ergot isolates from the Americas, Africa, India and Australia were studied to determine the possible origin of the C. africana clones introduced into the Americas and Australia. Comparison of nucleotide sequences (of internal transcribed spacer 1 and 5.8S rDNA regions) confirmed that C. sorghi, C. sorghicola and C. africana are three distinct species. The intraspecific variation within C. africana was studied (RAPD patterns) on 28 isolates from USA, Mexico, Puerto Rico, Bolivia, Australia, India and South Africa. It was further confirmed that C. africana occurs in India (see EPPO RS 99/097). Results showed that all American isolates were identical, and because 3 isolates of the same type came from South Africa, Africa was suggested as a possible origin for the invasive clones in the Americas. RAPD patterns of Australian and Indian isolates were distinguished only by a single band, suggesting an Asian origin for the clones introduced into Australia.
Pažoutová, S.; Badyopadhyay, R.; Frederickson, D.E.; Mantle, P.G.; Frederiksen, R.A. (2000) Relations among sorghum ergot isolates from the Americas, Africa, India and Australia.
Plant Disease, 84(4), 437-442.