Genetic variability identified in populations of the rice weed starfruit (Damasonium minus) by simple sequence repeats

F.G. JahromiA, G.J. AshA and E.J. CotherB

A Farrer Centre, School of Agriculture, Charles Sturt University, PO Box 588, 2678 Australia.

B Agricultural Institute, Forest Road, Orange, 2800 Australia.


Summary

Starfruit (Damasonium minus) is one the most important weeds of rice in Australia and has developed resistance to the main herbicide (bensulfuron-methyl) used for its control. A fungal pathogen, Rhynchosporium alismatis, is being investigated as a biocontrol agent for the integrated management of this weed. The genetic variability of populations of a weed may influence the success of this approach to its control. The variability of starfruit populations was compared at the molecular level using simple sequence repeats (SSRs). Forty-seven individual starfruit plants originating from seeds harvested from 18 locations across the rice-growing areas were used. The small patterns of variability between samples did not always relate to their geographic locations. As little variability was found it could be expected that the disease caused by the biocontrol agent would be the same across different weed populations. The agronomy, rather than genetic variability, of the weed may be the cause of its variable response to herbicides across rice-growing regions.

 

Plant Protection Quarterly (2002) 17 (4) 151-154.