Zymoseptoria tritici, the fungus that causes Septoria tritici blotch (STB) of wheat, is spread by splash borne transfer from the base of the plant to the flag leaf. This project is on a potential new source of resistance to STB discovered on chromosome 6A using association mapping (Arraiano & Brown 2016). Near isogenic lines generated for this region show no significant differences in STB symptoms when leaves are directly inoculated with Z. tritici. However, trials that are naturally infected or inoculated at the base of the plant show clear differences in their level of STB. This indicated that this region contains genes that cause differences in disease escape. The fact that the same marker Psp3071 is associated with yield traits (Snape et al, 2007) led to the hypothesis that the region may control a physiological trait that improves yield at the cost of aiding spore transmission. Candidate physiological traits, that could influence disease escape, have been tested in the 6A NILs including plant height, leaf area and senescence. The trait that fits with the pattern of the disease results best is leaf emergence, with later emerging leaves getting more STB. However, the effect of the 6A alleles on disease escape may be caused by multiple traits. Recombinant lines generated for the region have reduced the interval that contains the yield traits, though it is still unclear if the disease escape and yield effects are connected by linkage or pleiotropy.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:687889 |
| Date | January 2015 |
| Creators | Judge, Christopher |
| Publisher | University of East Anglia |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://ueaeprints.uea.ac.uk/59397/ |
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