CODOMINANT INTERPRETATION OF A DOMINANT SCAR MARKER LINKED WITH POTYVIRUS RESISTANCE IN COMMON BEAN

Authors: Vandemark, George; Miklas, Phillip - Phil

Submitted to: Bean Improvement Cooperative Annual Report
Publication Type: Abstract Only
Publication Acceptance Date: 1/1/2002
Publication Date: 4/1/2002
Citation: VANDEMARK, G.J., MIKLAS, P.N. CODOMINANT INTERPRETATION OF A DOMINANT SCAR MARKER LINKED WITH POTYVIRUS RESISTANCE IN COMMON BEAN. BEAN IMPROVEMENT COOPERATIVE ANNUAL REPORT, 45:102-103. 2002.

Interpretive Summary:

Technical Abstract: A major disadvantage of many PCR based RAPD and SCAR markers is that they exhibit dominant inheritance, and thus cannot be used to discriminate between homozygous (AA) and heterozygous (Aa) genotypes. An F2 population segregating for the bc-12 gene and linked dominant SCAR marker SBD51300 was used to investigate whether codominant interpretation of a dominant SCAR marker was plausible using quantitative PCR techniques. Quantitative PCR o the Taqman probe, specifically developed for the dominant SBD5 SCAR marker, correctly (100 percent) discriminated heterozygous bc-1//bc-12 plants from homozygous bc-12//bc-12 plants in the F2 generation as confirmed by F3 progeny tests for reaction to NL-3 strain of BCMNV. Our results indicate that the method employed in this study for assigning plant genotype based on quantitative PCR may be broadly applicable to the genotyping of diploid plants for other loci of interest for which only dominant PCR linked markers are available. The application of the quantitative PCR assay described herein will result in more timely population improvement and reduce greenhouse and field space requirements dedicated to progeny testing for disease resistance, as plants that are homozygous for dominant marker- linked resistance genes can be identified as seedlings.