Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 3/10/2002
Publication Date: 11/1/2002
Citation: BANDYOPADHYAY, R., MUTHUSUBRAMANIAN, V., TOOLEY, P.W., CHAKRABORTY, S., PAZOUTOVA, S., NAVI, S.S. ANALYSIS OF CLAVICEPS AFRICANA AND C. SORGHI FROM INDIA USING AFLPS, EF-1 ALPHA GENE INTRON 4, AND BETA-TUBULIN GENE INTRON 3. BOOK CHAPTER. pp75-79. IN Sorghum and Millet Diseases, J.F. Leslie, ed, Iowa State Press, Ames, IA 504pp.2002.
Interpretive Summary: Ergot disease of sorghum causes serious losses in major sorghum growing regions of the world. In India, ergot was first reported to occur in 1917 and its presence there has been consistent since that time. Epidemics of sorghum ergot do not occur every year, but are dependent on a favorable environment for disease to occur. In 1999-2000, serious ergot epidemics occurred in major sorghum-growing regions of India. We studied the major characteristics of the disease-causing fungal strains isolated from diseased material collected during these epidemics, and found that two species of fungi were causing ergot disease. One species, Claviceps sorghi, was found in very low frequency compared with the other species, C. africana. The ability of C. africana to produce more spores than C. sorghi may be why it predominates in India currently.
Technical Abstract: Sorghum ergot is a serious constraint in the production of F1hybrid seeds, an essential input in productive sorghum cultivation systems. Until 1991, Claviceps sorghi was considered to be the only perfect stage of Sphacelia sorghi McRae found to occur in India. In 1990, Claviceps africana, another perfect stage of Sphacelia sorghi, was reported from Africa, America, and Australia. Its presence has also been confirmed in India. The two pathogens show variations in cultural characters, sphacelial morphology, conidial morphology and teliomorphic characters. All major sorghum growing areas of seven Indian states were surveyed in 1999-2000, and both pathogens were found to be present. C. africana was found to be much more common than C. sorghi, indicating that it has replaced C. sorghi as the dominant, ergot-causing species in India.