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ARS Home » Midwest Area » West Lafayette, Indiana » Crop Production and Pest Control Research » Research » Publications at this Location » Publication #66012
Title: MAPPING OF THE PC GENE, A DISEASE RESISTANCE GENE IN SORGHUM

Author
item LEE, TSO-CHING - PURDUE UNIVERSITY
item DWEIKET, ISMAIL - PURDUE UNIVERSITY
item Dunkle, Larry

Submitted to: Plant Genome Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/15/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The single pc gene in sorghum (Sorghum bicolor) controls both the host plant reaction to the root rot pathogen Periconia circinata and the response to peritoxin, a host-selective toxin produced only by pathogenic strains of the fungus. Susceptibility of sorghum to the fungus is strictly correlated with sensitivity to peritoxin. To map and eventually clone the pc gene, we crossed the susceptible (PcPc) cultivar "Colby" with the resistant (pcpc) cultivar "Shanqui Red" to develop an F2 population. Genotypes of F2 individuals were determined by root growth inhibition bioassay of F3 families with peritoxin preparations. Bulked DNAs from susceptible (toxin-sensitive) or resistant (toxin-insensitive) plants were screened for RAPD markers that cosegregated with the susceptible or resistant phenotypes. Five RAPD markers were identified in a screen of 600 arbitrary primers; two of the markers cosegregated with the susceptible phenotype and three with the resistant phenotype. Recombinants in the F2 population were detected and used to determine the order of the markers and their distances from the pc gene. Data on the genetic map of the markers with respect to the gene will be presented. To identify additional markers, we have analyzed the same segregating population by AFLP and will present between seed protein and seed oil in each population with R2 values the results of those studies.