Plant Pathogen RFLP Mapping
Texas A&M University
This project is attempting to find RFLP or RAPD markers associated with traits conditioning disease resistance in sorghum. Most of our work to date has been on diseases caused by the highly variable pathogens Peronosclerospora sorghi, Sporisorium reilianun and Colletotrichumgraminicola that cause downy mildew, head smut and anthracnose, respectively. At least one gene has been mapped for sorghum downy mildew, but is some distance away from genomic markers. Crosses between susceptible and resistant parents and their respective progeny have been made and are ready for use in screening by potential probes. Work on the variability in the pathogens (See TAM-124) is closely monitored as a strategy for selecting pathogen isolates to be used in evaluation of host reac-tion to disease. Even though some pathogen isolates can overcome some host resistance genes, these genes can still be located by using less virulent isolates.
1. To map the relative location of each resistance-gene-linked-RAPD marker by using it as a restriction fragment length polymorphism (RFLP) probe on an F2 mapping population that is already available, 2. To identify different genes that confer resistance for each disease and genes that potentially provide resistance to mre than one disease.