Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2004
Publication Date: 7/30/2004
Citation: Friesen, T.L., Faris, J.D., Steffenson, B.J. 2004. Mapping of a major net blotch resistance gene in the Q21861 x SM89010 doubled haploid population.. American Phytopathological Society Abstracts. Vol. 91:532
Technical Abstract: Pyrenophora teres Drechs. f. teres Smedeg causal agent of net blotch on barley is an economically important pathogen worldwide. The objective of this study was to evaluate resistance to net blotch in segregating barley populations and identify molecular markers linked to major resistance genes. The Q21861 X SM89010 doubled haploid population consisting of 125 barley lines was used to evaluate the genetics of resistance. The barley population was inoculated with two P. teres isolates (15A and 0-1) which differ in virulence based on a barley differential set. Q21861 was highly susceptible and SM89010 was highly resistant to both pathotypes. Phenotypic analysis showed that the same resistance locus was effective against both pathotypes. The population segregated in a 79:46 resistant: susceptible ratio which is significantly different than the expected 1:1 segregation. AFLPs and SSRs along with bulked segregant analysis were used to identify markers associated with resistance. Markers flanking a single major resistance locus were identified, and these markers also showed skewed segregation indicating that the single major resistance gene lies within a genomic region of skewed segregation.