Link to home

AFLP Comparisons Among Claviceps africana Isolates from the United States, Mexico, Africa, Australia, India, and Japan

November 2002 , Volume 86 , Number  11
Pages  1,247 - 1,252

Paul W. Tooley , Erin D. Goley , and Marie M. Carras , USDA-ARS, Foreign Disease-Weed Science Research Unit, 1301 Ditto Ave., Ft. Detrick, MD 21702-5023 ; and Nichole R. O'Neill , USDA-ARS, Molecular Plant Pathology Laboratory, Beltsville, MD 20705

Go to article:
Accepted for publication 28 June 2002.

Eighty-seven isolates of the sorghum ergot pathogen, Claviceps africana, from diverse geographic locations were analyzed using four different amplified fragment length polymorphism (AFLP) primer combinations to determine genetic relationships among isolates. Most isolates showed unique AFLP haplotypes, indicating that substantial genetic variation is present within C. africana populations. Two major groupings of isolates were observable, with ca. 70% similarity between the two groups. One group consisted of Australian, Indian, and Japanese isolates and the other of U.S., Mexican, and African isolates. In spite of overall high levels of genetic diversity observed in C. africana, isolates within the two major groups were between 75 and 100% similar. The observed associations of C. africana isolates from worldwide sources could be the result of intercontinental trade and/or movement of seed. The data indicate that Africa was the likely source of C. africana that has become established in the Americas since 1996. Analysis of additional isolates in future studies will reveal whether these groupings are being maintained or whether population subdivision or reshuffling may occur.

Additional keywords: population genetics, Sphacelia sorghi, sugary disease

The American Phytopathological Society, 2002