HOST RANGE OF SORGHUM ERGOT PATHOGENS C. AFRICANA AND C. SORGHI IN INDIA

Authors: MUTHUSUBRAMANIAN, V. - NRCS; BANDYOPADHYAY, R. - IITA, NIGERIA; Tooley, Paul; REDDY, D. RAJARAM - ANGRAU

Submitted to: Journal of Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/2004
Publication Date: 1/5/2005
Citation: Journal of Phytopathology 153:1-4

Interpretive Summary: Sorghum ergot is a destructive disease in all major sorghum growing regions of the world. The ergot fungus has been observed to infect hosts other than sorghum and it is important to determine which alternative hosts are susceptible to the two primary species of ergot fungi. We tested 20 possible hosts for the ergot fungi and found that five plant species could serve as hosts. We evaluated the shapes and sizes of ergot spores produced on these hosts and compared them with spores produced on sorghum. This knowledge will help growers identify which alternative host plants in their regions may harbor growth of the ergot fungus and provide a supply of ergot spores that may infect the sorghum crop. Management practices for sorghum ergot must take these alternative hosts into account.

Technical Abstract: Among 20 graminaceous plant species evaluated for their role as collateral hosts for the two sorghum ergot pathogens Claviceps sorghi and C. africana, only five species viz., Sorghum arundinaceum, S. halepense, S. versicolor, S. virgatum, and Pennisetum glaucum were found to be hosts for both the pathogens, while the rest of them were non-hosts. There was marked variation in the size of macroconidia of the sorghum ergot pathogens produced on different hosts. The shape of the macroconidia on P. glaucum showed dimorphism, as some were elliptical and some were spindle shaped. We conclude that C. sorghi and C. africana have similar host ranges.