Association Mapping DNA Markers to Leaf Spot Resistance in Cultivated Peanuts that can be used in Breeding Program

Progress Report (through Dec. 2013) 
In order to determine resistance reactions with precision, disease evaluations must be conducted in controlled environments (i.e., growth chambers or greenhouse). In order to do such evaluations, the pathogen(s) must be available in particular growth stages, i.e., they must be producing spores. 
Cercospora arachidicola and Cercosporidium personatum are the fungi that cause early and late leaf spots of peanuts. Both of these fungi grow very slowly in culture. We have successfully established cultures of both of these fungi from isolates occurring in Alabama fields. In addition, we have successfully produced conidia on culture plates and determined an optimum medium and incubation time for maximum spore production. ??ttempts have been made to inoculate plants with C. arachidicola inoculum, but have not been successful to date. Lack of success with inoculation may be due to low humidity levels or insufficient duration of high humidity.