Quantitative trait loci analysis for resistance to Cephalosporium stripe, a vascular wilt disease of wheat uri icon

abstract

  • Cephalosporium stripe, caused by Cephalosporiumgramineum, can cause severe loss of wheat(Triticum aestivum L.) yield and grain quality and can bean important factor limiting adoption of conservation tillagepractices. Selecting for resistance to Cephalosporiumstripe is problematic; however, as optimum conditions fordisease do not occur annually under natural conditions,inoculum levels can be spatially heterogeneous, and little isknown about the inheritance of resistance. A population of268 recombinant inbred lines (RILs) derived from a crossbetween two wheat cultivars was characterized using fieldscreening and molecular markers to investigate the inheritanceof resistance to Cephalosporium stripe. Whiteheads(sterile heads caused by pathogen infection) were measured on each RIL in three field environments under artificiallyinoculated conditions. A linkage map for this populationwas created based on 204 SSR and DArT markers. A totalof 36 linkage groups were resolved, representing portionsof all chromosomes except for chromosome 1D, whichlacked a sufficient number of polymorphic markers.Quantitative trait locus (QTL) analysis identified sevenregions associated with resistance to Cephalosporiumstripe, with approximately equal additive effects. FourQTL derived from the more susceptible parent (Brundage)and three came from the more resistant parent (Coda), butthe cumulative, additive effect of QTL from Coda wasgreater than that of Brundage. Additivity of QTL effectswas confirmed through regression analysis and demonstratesthe advantage of accumulating multiple QTL allelesto achieve high levels of resistance

publication date

  • 2011
  • 2011