|Gulya Jr, Thomas|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/14/2007
Publication Date: 1/23/2008
Citation: Yue, B., Radi, S.A., Vick, B.A., Cai, X., Tang, S., Knapp, S.J., Gulya, T.J., Miller, J.F., Hu, J. 2008. QTL for Sclerotinia Head Rot Tolerance in a Sunflower Population Developed from a Cross Between Tolerant Lines [abstract]. 6th Annual Sclerotinia Initiative Meeting, January 23-25, 2008, Bloomington, MN. p. 34.
Technical Abstract: One hundred and twenty-three F2:3 and F2:4 families derived from a cross between HA 441 and RHA 439, both showing partial tolerance to Sclerotinia head rot, were used for the current study. A genetic map with 180 TRAP, 32 SSR, 11 INDEL, and 2 morphological markers was constructed. The map has 19 linkage groups and spans a genetic distance of 1797.6 cM. Disease incidence (DI) and disease severity (DS) were evaluated in three field tests in a randomized complete block design with two replicates. Strong positive correlations were detected among the traits investigated in different tests. Nine DI and seven DS quantitative trait loci (QTL) were identified with LOD scores ranging from 2.4 to 11.8. QTL were found in ten linkage groups. One DI QTL was detected in all three experiments and four (two DI and two DS) QTL were identified in two of the three experiments. Identification of the tolerance QTL will facilitate marker-assisted selection of the disease tolerance in germplasm development and breeding. Although a positive correlation existed between the two disease indexes, most of the respective QTL were located in different chromosomal regions, suggesting a different genetic basis for the two indexes.