Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xv, 122 p.; also includes graphics. Includes bibliographical references (p. 117-122). Available online via OhioLINK's ETD Center

Diss. (sammanfattning) SLU, Alnarp : Sveriges lantbruksuniversitet, 2008. / Härtill 4 uppsatser.

Thesis (MSc)--Stellenbosch University, 2012. / Triticale is an amphidiploid that consists of wheat (A and B) and rye (R) genomes. This cereal is fast becoming important on a commercial basis and warrants further assessment for the better management and breeding of the hybrid. The assessment of the genetic diversity among the wheat and rye genomes within triticale can be obtained by using molecular markers developed in both donor genomes. Simple sequence repeats markers (SSRs) and amplified fragment length markers (AFLPs) have been previously used to assess the genetic diversity among triticale lines. SSRs are highly polymorphic markers that are abundant and which have been shown to be highly transferable between species in previous studies while AFLP markers are known to generate plenty of data as they cover so many loci. Thus, the aim of this study was to develop a marker system suitable to assess the genetic diversity and relationships of advanced breeding material (and cultivars) of the Stellenbosch University’s Plant Breeding Laboratory (SU-PBL). Therefore, both AFLP and SSR markers were initially analysed using eight triticale cultivars (with known pedigrees) to facilitate cultivar identification. Fourty-two AFLP primer combinations and 86 SSR markers were used to assess the genetic diversity among the Elite triticale cultivars. The AFLP primer combinations generated under average polymorphism information content (PIC) values. Furthermore, these markers generated neighbour-joining (NJ) and unweighted pair group method with arithmetic average (UPGMA) dendograms that displayed relationships that did not correspond with the available pedigree information. Therefore, this marker system was found not to be suitable. A set of 86 SSRs previously identified in both wheat and rye, was used to test the genetic diversity among the eight cultivars. The markers developed in wheat achieved 84% transferability while those developed in rye achieved 79.3% transferability. A subset of SSR markers was able to distinguish the cultivars, and correctly identify them by generating NJ and UPGMA dendograms that exhibited relationships that corroborated the available pedigree data. This panel of markers was therefore chosen as the most suitable for the assessment of the advanced breeding material. The panel of seven SSR markers was optimised for semi-automated analysis and was used to screen and detect the genetic diversity among 306 triticale entries in the F6, Senior and Elite phases of the SU-PBL triticale breeding programme. An average PIC value of 0.65 was detected and moderate genetic variation was observed. NJ and UPGMA dendograms generated showed no clear groupings. However, the panel of markers managed to accurately identify all cultivars within the breeding program. The marker panel developed in this study is being used to routinely distinguish among the advanced breeding material within the SU-PBL triticale breeding programme and as a tool in molecular-assisted backcross.

O Brasil é país detentor de grande biodiversidade, no entanto pequena parcela dessa já foi estudada e catalogada. Os recentes avanços antrópicos sobre os ecossistemas naturais tem levado a sua rápida fragmentação e eliminação de alguns biótipos ainda não estudados ou catalogados. Nessa realidade de erosão genética acelerada encontra-se também espécies de jabuticabeira (Plinia sp.) que são endêmicas do Centro Sul/Sudoeste do Paraná, no ecossistema Floresta com Araucária. Medidas de conservação de germoplasma para uso atual e futuro, bem como táticas de manejo e conservação dos recursos naturais são preponderantes para reduzir ao mínimo os danos causados a biodiversidade brasileira. Para tanto é necessário entender a diversidade genética existente nos ecossistemas naturais, que é o insumo básico para a sobrevivência e evolução entre os indivíduos frente as modificações ambientais. No presente trabalho foi realizado a caracterização genética de 110 jabuticabeiras que constituem o banco ativo de germoplasma desta espécie na UTFPR – Câmpus Dois Vizinhos. Foi possível identificar a transferibilidade de 9 marcadores moleculares microssatélites (SSR) com caráter polimórfico para a população estudada, e realizar a padronização de reação de PCR para cada um deles. Da análise das jabuticabeiras do banco ativo de germoplasma chegou-se a conclusão de que o mesmo abrigou valor considerável de diversidade alélica. No entanto tal diversidade está mal distribuída, já que 11 indivíduos sozinhos já são capazes de representar 59,2% de todos alelos da coleção de 110 plantas. Os valores encontrados de heterozigosidade observada e conteúdo informativo (PIC) nessa subpopulação de 11 indivíduos foram superiores aos valores encontrados para o conjunto integral do banco ativo. O agrupamento dos indivíduos mostrou a existência de 8 diferentes grupos, sendo que 89 indivíduos ficaram no grupo 1, demonstrando o seu possível grau de parentesco e baixo nível de diversidade genética. / Brazil is a country of great biodiversity holder, however small portion of that has been studied and cataloged. Recent advances human activities on natural ecosystems has led to its rapid fragmentation and elimination of some biotypes still, not it studied or cataloged. In this reality of genetic erosion is also accelerated jabuticaba tree species (Plinia sp.). That are endemic from South Central / Southeastern Paraná State, in Araucaria forest ecosystem. Germplasm conservation measures for current and future use, as well as tactics for management and conservation of natural resources are crucial to minimize the damage caused to Brazilian biodiversity. So it is necessary to understand the genetic diversity in natural ecosystems, which is the basic input for the survival and evolution among individuals facing environmental changes. In the present study was to characterize genetic of 110 jabuticaba tree fruit, that constitute the germoplasm bank of jabuticaba tree fruit from UTFPR - Câmpus Dois Vizinhos. It was possible to identify transferability of 9 microsatellite markers (SSR) with polymorphic character for the population studied, and it carry out standardization of PCR reaction for each of them. The analysis of plant germoplasm bank came to the conclusion that houses a considerable amount of allelic diversity, but this diversity is poorly distributed, since 11 individuals alone are already able to represent 59.2% of all alleles of the collection of 110 plant. The found values of, observed heterozygosity and information content (PIC) in this subpopulation of 11 individuals were higher than the values found for the full set of the germoplasm bank. The grouping of individuals showed the existence of 8 different groups, and 89 subjects were in group 1, demonstrating a possible relationship and low level of genetic diversity.

Philosophiae Doctor - PhD / Apple fruit quality is of utmost importance to apple farmers and breeders in the selection and commercialization of new cultivars. Fruit size, colour, texture, firmness and taste are all traits that affect the quality of fruit. In this study the genetic contribution of these traits, and others were evaluated in order to generate the genetic markers required for the application of marker assisted selection in fruit quality breeding. Three mapping populations, ‘Prima’ x ‘Anna’, ‘Golden Delicious’ x ‘Priscilla’ and ‘Golden Delicious’ x ‘Anna’, consisting of 87, 87 and 141 respectively, were used in the study. Fruit samples were analysed, using a range of visual, physical and sensory measurements, over a period of three years, and the data was then correlated using statistical analysis. Traits analysed included stripe-ness, fruit colour, fruit size, fruit form, ground colour, russet, texture, fruit firmness, juiciness, sugar content, acidity, taste, skin toughness, %TSS, fruit mass and diameter. ANOVA detected significant levels of variation between the three families for all traits except taste and russet; while highly significant ‘within family’ variation was also observed for all traits in pre- and post-storage analyses, except for sugar content (sweetness) and fruit form. Within family variation also contributed the largest percentage towards the variance components of all traits. Heritability estimates found stripe-ness to be the most heritable trait, from subjective analyses, while heritability values ranged from 0.41 to 0.84 for instrumentally measured traits. The genetic maps for the three populations were generated using both published microsatellites and new EST-SSR and DART markers, using JoinMap 4.0". The integrated genetic linkage maps of ‘Prima’ x ‘Anna’, ‘Golden Delicious’ x ‘Priscilla’, ‘Golden Delicious’ x ‘Anna’ consisted of 398 (133 SSR and 265 DArT), 353 (80 SSR and 273 DArT) and 213 (87 SSR and 126 DArT) markers respectively. The maps were 1021.6cM, 1079cM and 1302.7cM in length, respectively. Location of quantitative trait loci (QTL) for 14 fruit quality traits was detected using MapQTL 5.0" and a total of 79 pre-storage and 60 poststorage QTLs were identified on the three mapping populations. Comparative genome analysis and the role of various genes on the outcome of fruit quality can now be investigated. Using the integrated genetic maps, and the QTLs identified, candidate markers associated with these QTL can be used for marker-assisted selection, to increase the speed and efficiency of the apple breeding program.

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