Download or read book Genetic Characterization of Barley and Pyrenophora Teres Host Pathogen Interactions written by Shaun James Clare and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Net blotch is a globally important pathogen of barley, causing economic loss worldwide due to 10-40% yield reduction or quality degradation when susceptible varieties are grown under conditions conducive to disease development. There are two forms of net blotch, termed net form net blotch caused by Pyrenophora teres f. teres (Ptt) and spot form net blotch caused by Pyrenophora teres f. maculata (Ptm). In addition, Ptm has recently been reported to infect wheat, exhibiting symptomology resembling the closely related pathogen Pyrenophora tritici-repentis causing the wheat disease tan spot. Previously, the limited analysis of barley-Ptm genetic interactions suggested limited overlaps with Ptt, thus it was suggested that the two pathosystems should be considered separate. However, the data presented here shows that there are several overlapping resistance/susceptibility loci between the two pathosystems, thus this recommendation may not be entirely correct. Over 500 barley loci have been reported in respect to Ptm and Ptt resistance or susceptibility using association or biparental mapping. These 500+ loci were collapsed into 73 consensus loci with 34 loci overlapping between the two forms of net blotch. Subsequently, association mapping was performed in wild and landrace barley against both Ptm and Ptt identifying 14 loci, four of which are novel. The first association mapping was also performed on 127 Ptm isolates inoculated on 30 barley accessions identifying 30 pathogen virulence loci, 26 of which are novel, including one that exhibits reciprocal virulence on different barley genotypes. Subsequently, candidate gene identification was performed for the reciprocal virulence locus designated Pyrenophora teres f. maculata Disease inducing effector 1 (PtmDie1) by performing genome assembly of the Ptm isolate 13IM8.3. Lastly, biparental mapping was conducted on an F2 mapping population exhibiting hybrid susceptibility designated the Susceptibility to Pyrenophora teres 2 (Spt2) gene despite the utilization of two resistant parents. The locus was mapped to a 249 kb region of the Morex reference genome assembly containing two candidate genes.