Comparisons using cDNA (cloned DNA from expressed genes) from different species greatly increases our understanding and ability to identify the changes in the genetic content of related species through the process of evolution.This research utilized cDNA isolated from developmentally staged female flowers of Tripsacum, a relative of modem maize (corn) with differing modes of reproductive behaviors. The gene expression clone libraries potentially carry the gene(s) responsible for the regulation of fertility, both apomixis and sexual reproduction, in Tripsacum sp. A set of yeast genes with known functions in the reproductive cell division known as meiosis were also investigated, but failed to hybridized to DNA of the maize mapping population.The Tripsacum cDNAs, E2-42 and M2-62, showed monomorphic band patterns, i.e., no differences between individuals. Possibility the quantity of E242 and M2-62 Tripsacum cDNAs for these locus were highly conserved with respect to the fragment lengths generated by restriction digestion of the test individuals. The Tripsacum cDNA sequence L4-14 revealed polymorphic bands patterns when used as a probe for mapping. The L4-14 polymorphisms were scored as both 1:2:1 and 3:1 segregation ratios and mapped to a subset of ordered loci from the Maize Database genome bank, University of Missouri. Two genetic map regions were identified as linked to the L4-14 locus. These regions included bin 6.05-6.08 of chromosome 6 and bin 8.00-.05 of chromosome 8. Linkage to two different chromosomal regions indicated that the L4-14 sequence may be duplicated within the maize genome. Results and discussion of this investigation and analyses are presented. / Department of Biology

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Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 80-86).

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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

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 53-67). / x, 67 leaves, bound ill. 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 69-79). / ix, 79 leaves, bound ill. 29 cm

Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 53-62). / ix, 62 leaves, bound ill. (some col.) 29 cm

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