Association of fusarium head blight resistance with gliadin loci in a winter wheat cross

Fusarium head blight (FHB) is one of the major diseases of wheat (Triticum aestivum L.). Genetic control of resistance to Fusarium spp. has been studi ed in resistant Chinese spring wheat cultivars, but little is known about i nheritance of lower but useful levels of resistance found in winter wheat. This study was undertaken to characterize the genetic control of FHB resist ance and to identify possible associations of resistance with several marke r loci in winter wheat. Recombinant inbred lines were derived from the cros s of a susceptible winter wheat, F1054W, with a moderately resistant parent , Sincron, not related to the Chinese germplasm, The parents had different alleles: at five marker loci, RhtB1, Rht8, W2, GliB1, and GliD1. Recombinan t inbred lines Il ere classified for alleles at the RhtB1 and Rht8 loci by plant height and seedling response to exogenous gibberellic acid. Alleles a t the GliB1 and GliD1 loci were determined Front the gliadin spectrum detec ted by starch gel electrophoresis and alleles at the W2 locus by phenotypes in the field. The area under disease progress curve (AUDPC) and relative w eight of inoculated spikes (RWIS), following injection of Fusarium graminea rum Schwabe inoculum into central florets of flowering spikes, were determi ned for 3 yr in the field. A significant increase in resistance was associa ted with the allele GliR1, suggesting location of a Fusarium head blight re sistance quantitative trait locus (QTL) on chromosome T1BL.1RS. A smaller b ut significant increase in resistance was associated with allele GliD1b, in dicating the presence of another QTL on chromosome 1D, No association betwe en Fusarium resistance and RhtB1, Rht8, or W2 was found. The effects of fav orable alleles on chromosomes 1B and LD,were cumulative, Selection for geno types possessing GliR1 and GliD1b in this population would increase the pro bability of obtaining lines with higher resistance to Fusarium head blight.