Molecular mapping of quantitative trait loci controlling Fusarium head blight resistance and deoxynivalenol accumulation in two winter wheat double haploid populations
| dc.contributor.author | Mwaniki, Alice | |
| dc.contributor.examiningcommittee | Fernando, Dilantha (Plant Science) Crow, Gary (Animal Science) McCartney, Curt (Plant Science) Francois Belzile, Francois (Phytology, Laval University) | en_US |
| dc.contributor.supervisor | Brûlé-Babel, Anita (Plant science) | en_US |
| dc.date.accessioned | 2018-01-10T18:43:16Z | |
| dc.date.available | 2018-01-10T18:43:16Z | |
| dc.date.issued | 2017 | |
| dc.degree.discipline | Plant Science | en_US |
| dc.degree.level | Doctor of Philosophy (Ph.D.) | en_US |
| dc.description.abstract | Fusarium head blight (FHB) caused by Fusarium graminearum leads to severe yield and quality losses in wheat, but the most serious concern is the accumulation of mycotoxins such as deoxynivalenol in food and feed. Development of resistant varieties is an important component of integrated control of this fungal disease. Two large double haploid (DH) populations were developed using CDC Buteo as the moderately resistant parent. The objective was to detect (quantitative trait loci) QTL for resistance against FHB. The 19H*16/CDC Buteo cross (9HBT, N=228) produced six DH lines with <10% Fusarium head blight index (FHB index) and 56 lines with FHB index of 10-20%. The cross 22A*13/CDC Buteo (2ABT, N=218) produced 93 lines with an FHB index of 10-20%. For all FHB traits investigated, FHB resistance QTL were identified on 13 chromosomes with stable QTL on 2B, 4A, 4B, 4D, 6B and 7A for the 9HBT population. The 4B and 4D QTL mapped on the exact positions for the Rht-B1 and Rht-D1 dwarfing genes, respectively, and they explained the largest proportion of phenotypic variation. CDC Buteo contains allele combination Rht-B1b/Rht-D1a while 19H*16 contains Rht-B1a/Rht-D1b. Anther retention (AR) results for the cross 19H*16/CDC Buteo, showed that low AR was correlated with increased FHB resistance. Anther retention is a stable trait which can be used for indirect selection in FHB resistance. Classification of the 9HBT population into genotypic groups based on Rht genes identified double wild-type (Rht-B1a/Rht-D1a) that were the tallest with low anther retention (AR) and reduced FHB infection compared to double dwarf mutants (Rht-B1b/Rht-D1b) that were very short with high AR and high FHB infection. The allele combination Rht-B1b/Rht-D1a had lower AR and lower disease symptoms than Rht-B1a/Rht-D1b, but almost the same plant height. Nineteen QTL were reported for 2ABT with stable QTL expressed on chromosomes 2B, 3B, 4B, 6A and 6B. Stable QTL reduced multiple FHB-related traits and could be used for improving FHB resistance in wheat. The two DH populations showed somewhat different results in terms of QTL detected. | en_US |
| dc.description.note | February 2018 | en_US |
| dc.identifier.uri | http://hdl.handle.net/1993/32783 | |
| dc.language.iso | eng | en_US |
| dc.rights | open access | en_US |
| dc.subject | QTL mapping | en_US |
| dc.subject | Fusarium head blight | en_US |
| dc.subject | CDC Buteo | en_US |
| dc.subject | Fusarium graminearum | en_US |
| dc.subject | Wheat, Triticum aestivum L. | en_US |
| dc.subject | SNP | en_US |
| dc.title | Molecular mapping of quantitative trait loci controlling Fusarium head blight resistance and deoxynivalenol accumulation in two winter wheat double haploid populations | en_US |
| dc.type | doctoral thesis | en_US |