[...] The present study is an attempt to determine to what extent oat grain yield response to seeding rates and nitrogen fertilization, can be traced to the reaction of one or more of the yield components. [...]

No description available.

Many traits of economic importance in crop plants are quantitative, complicating the selection for desirable characteristics. Recent studies suggest a complex relationship between genotype and phenotype, with genetic variability often appearing as differences in gene expression rather than structural changes in proteins. In oat (Avena sativa L.), lipid and protein content are economically important traits. In the first of four studies reported here, partial sequences for eight genes involved in lipid or protein biosynthesis were obtained from ten oat cultivars with varying lipid and protein content. Phylogenetic analysis showed that these sequences clustered into families possibly corresponding to homeologous genes. Some cultivar- and family-specific polymorphisms were identified. In the second study, we surveyed differential gene expression between developing kernels of cultivars Kanota and Ogle by constructing reciprocal subtractive libraries. Of the 195 contig sequences obtained, only a minority had homology to characterized sequences. Grouping these sequences in categories based on gene ontology of their BLAST hits showed different profiles of expression for each cultivar. In the third study, we tested a method for transforming macroarray data consisting of dividing spot signal by the median array background. This reduced variation due to array exposure time. In the fourth study, gene expression levels were considered as quantitative traits in the Kanota x Ogle mapping population. Macroarrays featuring oat clones differentially expressed between both parents were hybridized with cDNA from the population lines. Among the 33 significant expression quantitative trait loci detected, most clustered to linkage group 29--43, a possible "hot-spot" of gene expression regulation.

Two experiments were conducted in 1994 and 1995 to compare the field performance of photoperiod sensitive (PS) and photoperiod insensitive (PI) oat (Avena sativa L) genotypes. In the first experiment, bulks of PS and PI lines from four covered oat crosses, as well as the cultivars Sylva, Newman, the PI naked oat cultivar AC Lotta and the breeding line NO820-3L were tested at seven locations across Quebec and Ontario. The second experiment was a seeding. date trial performed at Ste-Anne-de-Bellevue in which individual PS and PI lines of three covered oat crosses were utilized. In the multi-location experiment, the PI genotypes generally reached the different growth stages significantly earlier. At Normandin, Quebec the northernmost site, PS genotypes had consistently higher yields than the PI genotypes. At one southern site (Elora, Ontario), PI bulks yielded more than their PS counterparts. The PS genotypes sometimes had higher leaf numbers in most of the seven locations. In the experiment with different seeding dates, the PS lines had significantly higher numbers of leaves, biomass, grain weight per plant, harvest index, and yield compared to the PI lines. The response of the PS and PI lines to delayed sowing was similar. There was a progressive reduction in the number of days to reach Zadoks' 30, heading, and maturity: and a reduction in height, above-ground biomass, and yield with delayed sowing. Number of culms, leaves, and fertile culms, and harvest index were not affected by delayed sowing. Based on the results of these experiments, it seems that the Di1 gene does not confer any consistent yield advantage or disadvantage. Nevertheless, there may be some northern environments for which photoperiod sensitive oat genotypes are better suited.

No description available.

Thesis (Ph. D.)--University of Minnesota, 1924. / Published also as University of Minnesota Agricultural Experiment Station, Technical bulletin 35, December, 1925. "Literature cited": p. 32-33.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1940. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-58).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1953. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 84-85).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1949. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 87-88).

Presented as Thesis (Ph. D.)--University of Wisconsin--Madison, 1918. / Cover title. Reprinted from Journal of agricultural research, vol. XIX, no. 4 (15 May 1920). Includes bibliographical references (p. 172).