Submitted to: ARS Sclerotinia Initiative Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 1/21/2008
Publication Date: 1/23/2008
Citation: Soule, M., P. N. Miklas, and L. Porter. 2008. Identification of QTL conditioning partial resistance to white mold in kidney bean line VA19 derived from an interspecific population. National Sclerotinia Initiative 6th Annual Meeting, Jan. 23-25, 2008. p. 30.
Technical Abstract: Scarlet-runner bean (Phaseolus coccineus L.), a representative species of the secondary gene pool of common bean, is a potential source of white mold resistance for improving dry bean and snap bean. VA19 is a light-red kidney bean line that possesses resistance to white mold putatively derived from scarlet-runner bean. The objective of this research was to characterize resistance of VA19 to white mold in multiple field and greenhouse environments. A recombinant inbred population Benton/VA19 consisting of 79 F5-derived RILs was used for QTL analysis. ‘Benton’ is a susceptible snap bean. Separate R and S bulks based upon combined field and greenhouse reactions to white mold were used in bulked-segregant analysis to identify sequence-related amplified polymorphic (SRAP) markers associated with resistance. There were three QTL identified. Two QTL conditioned physiological resistance in the greenhouse. These QTL mapped to linkage groups B2 and B4. The QTL on B2 was detected by both the straw test (R2=38%) and a non-wounding technique (27%). This QTL was also expressed in the field (11%). The QTL on B4 was detected primarily by the non-wounding greenhouse screening method and had a minor effect (6%). The third QTL on linkage group B8 conditioned partial field resistance to white mold (11%) and was not associated with disease avoidance traits. Preliminary examination suggests that the B2 and B8 QTL derived from VA19 are independent of QTL derived from other resistance sources which map to the same linkage groups. Cloning and sequencing of QTL-linked SRAP markers is underway for potential identification of candidate genes underlying partial resistance and for development of user friendly SCAR markers for MAS of the QTL.