Barley (Hordeum vulgare L.) is the preferred cereal for malting. Its suitability for malting depends on many criteria, including the size, shape and uniformity of the kernels. Malting quality is affected by many quantitative trait loci (QTL). Such loci have been mapped using phenotypic and genotypic information on all members of mapping populations. It may also be possible to detect marker-QTL associations using selective genotyping, in which only the progeny with high or low phenotypic values for a trait are genotyped with available markers. Information on marker-QTL associations may be used in marker-assisted selection. Marker-assisted selection could be particularly useful for barley malting quality traits, some of which are costly to assess. Here, three studies were conducted related to QTL for barley grain and malt quality characteristics. In the first study, QTL were mapped using kernel size and shape data obtained by image analysis on samples from a two-rowed by six-rowed barley cross. QTL were detected near vrs1 on chromosome 2(2H) and near int-c on chromosome 4(4H). Some QTL affected the within-sample variability without affecting the mean of kernel characteristics. QTL alleles that made kernels larger and/or rounder also tended to improve malt quality. Those that increased the variability of kernel size were associated with poor malt quality. In the second study, marker genotype data and grain and malt quality phenotype data from three mapping populations were used to investigate the feasibility of selective genotyping for QTL mapping. Almost all previously mapped QTL were detected often with only 10% of the population genotyped. Additional, possibly spurious, QTL were detected in regions of the genome where no significant QTL had been mapped. The results indicated that simultaneous investigation of two or more traits by selective genotyping could be worthwhile. In the third study, Morex alleles at a QTL on chromosome 7(5H) affecting alpha-amylase activ
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.38459 |
| Date | January 2002 |
| Creators | Ayoub, Micheline |
| Contributors | Mather, D. E. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Plant Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001956338, proquestno: NQ85680, Theses scanned by UMI/ProQuest. |
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