Mapping quantitative trait loci in wheat involved in resistance against Russian

RICCIARDI M, TOCHO E, TACALITI MS, VASICEK A, GIMÉNEZ DO, SIMMONDS J, SNAPE JW

St. Petersburg

Conferencia; 8th International Wheat Conference; 2010

Organized by N.I. Vavilov Research Institute of Plant Industry (VIR)

Diuraphis noxia (Russian Wheat Aphid, RWA), the most aggressive pest of wheat, has evolved several biotypes, virulent to most of the resistance genes. The fast deployment of resistance requires the assessment of new sources. This paper was aimed at determining the location of plant-defence genes triggered by RWA in a set of recombinant doubled haploid (RDH) lines obtained from the cross between UK winter wheat varieties Spark and Rialto. Both parental lines and 110 RDH were screened for antixenosis, tolerance and antibiotic mechanisms of resistance with a population of RWA collected in Argentina. Antixenosis was significantly linked to marker locus Xgwm33 located on 1AS and to Xgwm193 on 6BS. Tolerance traits showed significant associations with several chromosomes. The foliar area developed during infestation was significantly associated with marker loci Xpsp3103 (4DS), and Xgdm3 (5DS). The chlorophyll content in the infested plants was significantly linked to marker loci Xgwm533 on 3BS, and to Xpsp3094 on 7AL and the number of expanded leaves was associated with marker loci Xwmc264 (3AS) and to XwPt-8836 (4DS). Most of the tolerance traits were significantly associated with the same chromosome interval on chromosomes 4DS and 5DS. The 4DS QTLs are linked to, or are a pleiotropic effect of, Rht-D1. Most of the antibiosis traits were significantly associated to the same marker loci on chromosomes 4A (XwPt-7405), 1B (XwPt-9032) and 5B (Xbarc109 and Xbarc74). Several novel genes conferring antixenosis, tolerance and antibiosis to RWA have been identified and these could be included in wheat cultivars to enlarge the genetic base of defence against this aphid pest. These new genes can be designated as new QDn.unlp genes, following the rules for gene nomenclature in wheat.