1 v. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Agronomy, 1980

Bibliography: leaves 183-211. / xii, 211 leaves ; col. ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study evaluates the backcross breeding method for the introgression in barley of agronomically important traits into a malting quality background using molecular markers. / Thesis (Ph.D.)--University of Adelaide, Dept. of Plant Science, 2000

No description available.

"November, 2003" / Bibliography: leaves 174-191. / viii, 196 leaves : ill. (some col.), photos (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study aims to identify and characterise novel alleles for key malting quality genes from wild barley, wild barley being a source of novel genetic variation that could be exploited to develop superior barley varieties. / Thesis (Ph.D.)--University of Adelaide, School of Agriculture and Wine, Discipline of Plant and Pest Science, 2004

Bibliography: leaves 183-211. This study evaluates the backcross breeding method for the introgression in barley of agronomically important traits into a malting quality background using molecular markers.

Wild barley (Hordeum vulgare subsp. spontaneum) could be a source of useful genes for improving cultivated barley. The useful genes present in Hordeum vulgare subsp. spontaneum may be new alleles at described loci, or these may be entirely new genes in the sense that there is limited allelic variation at these loci in the cultivated germplasm pool. This research was directed at gene discovery in wild barley and involved two steps: (i) characterization of diversity using genetic markers and (ii) development and characterization of novel germplasm for gene discovery. Simple Sequence Repeats (SSRs) of known map location were used to survey three representative groups of barley germplasm: a sample of crop progenitor (Hordeum vulgare subsp. spontaneum) accessions, a group of mapping population parents, and a group of varieties and elite breeding lines. The objectives were to determine the informativeness and utility of SSRs in differentiating and classifying the three sets of barley germplasm. Crop progenitors had the highest number of alleles per SSR locus, followed by mapping population parents and elite breeding lines. The cluster analysis indicated a high level of diversity within the crop progenitor accessions and within the mapping population parents. It revealed a much lower level of diversity within the elite breeding germplasm. A set of Recombinant Chromosome Substitution Lines (RCSLs) representing introgressions of Hordeum vulgare subsp. spontaneum genome in to a cultivated barley background were developed using the Advanced Backcross strategy. An accession of Hordeum vulgare subsp. spontaneum was the donor parent and the variety "Harrington" was the recurrent parent. The RCSLs were developed via two backcrosses to the recurrent parent followed by six generations of selfing. The genomic architecture of the RCSLs was determined by molecular marker fingerprinting with SSRs. The consequences of introgressions of Hordeum vulgare subsp. spontaneum genome segments into the recurrent parent were assessed in terms of inflorescence yield components, malting quality traits, and domestication-related traits. Hordeum spontaneum subsp. spontaneum, despite its overall inferior phenotype, contributed favorable alleles for some characters of agronomic performance. In other cases, the introgressions caused a disruption of the Harrington phenotype, a "reverse genetics" approach to gene discovery. / Graduation date: 2003

Higher grain yield is a key objective in barley (Hordeum vulgare. L) breeding. Despite extensive research on the genetics of yield and its components, selection for yield per se is still the most extensively employed because of negative relationships among components, modest correlations between yield and any particular component, and the additional resources required for measuring the components. The development of quantitative trait locus (QTL) detection procedures allows for an alternative approach to this issue. The objective of this investigation was to determine the biological basis of observed grain yield QTLs, with particular reference to yield components and yield-related traits. Yield and yield component traits were assessed in a population of spring barley doubled haploids from a cross of 'Steptoe' x 'Morex'. The scope of inference of the experiment was broadened by using reference QTL data sets from the multiple environment assessment of the same population. Both positive and negative relationships among yield, component, and related trait QTLs were observed. The QTL data indicate that indirect selection for yield via yield components would be ineffective. The yield QTL effects in this germplasm were largely attributable to lodging and basal internode length. Localization and interpretation of yield QTLs may be useful for studying orthologous gene expression in other germplasm and in developing multiple character selection strategies. / Graduation date: 1994

Four experiments were conducted with the objectives of (i) comparing the suitability of various H. bulbosum clones for haploid production, (ii) determining the parental effects of H. bulbosum and barley genotypes on percentage of pollinated florets yielding caryopses with rescuable embryos and on embryo viability, (iii) comparing different stages for embryo culture and caryopsis culture, and (iv) attempting to produce barley haploids directly from cultured immature caryopses. The results demonstrated: that reproductive characteristics of H. bulbosum clones varied with environmental conditions; that the hybrid H. bulbosum clones MBC-3 and MBC-4 were superior to their parents Cb2920 and Cb2929 as pollen donors; that both parental genotypes and date of harvesting after pollination had large effects on percentage of pollinated florets yielding caryopses with rescuable embryos and on embryo viability; that haploid plantlets can be generated from haploid caryopsis culture without embryo rescue, but only at a low frequency and with a slow rate of germination.

No description available.

No description available.