Quantitative trait loci analysis of four components of Fusarium head blight resistance in the soft red winter wheat cultivar Truman

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Fusarium head blight (FHB) mainly caused by Fusarium graminearum Schwabe [telomorph: Gibberella zeae Schw. (Petch)] causes devastating losses in wheat globally. Host-plant resistance provides the best hope for reducing economic losses but sources of resistance are limited. "Truman" soft red winter wheat, developed and released by the University of Missouri has excellent broad-based FHB resistance. This research was conducted to identify QTL associated with five components of resistance in Truman. Two years (2 replications per year) of phenotypic data were collected on these components of resistance on a set of 167 F9 recombinant inbred lines developed from the cross Truman/MO 94-317. Genetic linkage maps were constructed using 160 single sequence repeat and 530 diversity array technology polymorphic markers. Across years, QTL for type II resistance were identified on chromosomes 1BSc, 2BL, 2DS and 3BSc; for disease incidence on 2ASc, 2DS, and 3DS; for disease severity on 2DS, and 3BSc; for Fusarium damage kernels (FDK) on 2ASc, 2DS, and 3BLc; and for low DON on 2ASc, 2DS, and 3BLc. Additional QTL for FDK were identified on 1BLc, 2ASc, and 3BLc; and for DON on 2ASc, 2DS, and 6ALc were identified from phenotypic data collected in Kentucky. The effects of identified QTL ranged from 5.0 to 30.7 % of the total phenotypic variation. Several of these QTL appear to be potentially novel and therefore should enhance FHB resistance in programs attempting to pyramid unique FHB resistance genes through marker-assisted-selection.