Abstract
The major objective of this project is to understand the genetic basis and evolution of defense mechanisms in plant-virus interactions. We propose an interesting system involving the interactions between wild and domesticated wheat (Triticum spp.) and the Wheat dwarf virus (WDV). The wild ancestors of wheat are known and their distribution overlaps with the site of wheat domestication in Southern Turkey. WDV has been detected to infect wheat in this area, suggesting that the virus and the wild wheat populations may have coevolved. Although some variation in susceptibility occurs among wheat cultivars, there are no known resistant cultivars, and the wild ancestors may be the only sources of genes for resistance. The following hypotheses will be tested: 1) there is a variation in susceptibility to WDV within wild wheat populations and resistant genotypes have evolved in these populations, 2) the difference in susceptibility is controlled by multiple genes with different individual effects rather than with few genes of large effect. To test these hypotheses wheat cultivars of different ploidy levels (2n=14, 28, 42) and wild Triticum species will be characterized for susceptibility and resistance. Plants showing large difference in susceptibility will be crossed and the hybrids selfed. Quantitative trait loci (QTL) mapping analysis with DNA markers will be used to study the genetic basis of differences in susceptibility and resistance to WDV in the offspring (F2) generation.
Sweden