Thesis (Ph. D.) -- Lincoln University, 2009. / Also available via the World Wide Web.

Thesis (Ph. D.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 135-157).

Thesis (Ph. D.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Jan. 11, 2010). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Plant Science, Department of Agricultural, Food and Nutritional Science, University of Alberta." Includes bibliographical references.

published_or_final_version / Botany / Doctoral / Doctor of Philosophy

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

Thesis (M.Sc.)--University of Alberta, 2010. / Title from PDF file main screen (viewed on May 3, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Plant Science, Department of Agricultural, Food and Nutritional Science, University of Alberta. Includes bibliographical references.

Submitted by DOGLAS BASSEGIO null (doglas14@hotmail.com) on 2017-04-16T22:03:40Z No. of bitstreams: 1 Tese.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-18T17:47:05Z (GMT) No. of bitstreams: 1 bassegio_d_dr_bot.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) / Made available in DSpace on 2017-04-18T17:47:05Z (GMT). No. of bitstreams: 1 bassegio_d_dr_bot.pdf: 1143011 bytes, checksum: f84f0671d7fde4c59ee46871a3d37883 (MD5) Previous issue date: 2017-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O gênero Brassica é a terceira maior fonte de óleo vegetal do mundo, com oleaginosas cultivadas no Hemisfério Norte. No Brasil, apesar do aumento nos últimos anos, a espécie Brassica napus L., não é um cultivo tradicional, devido as limitações de fotoperíodo e altas temperaturas. Outras espécies do gênero, como é o caso da Brassica juncea L. e Brassica rapa L., amplamente cultivadas em zonas de baixa precipitação e fertilidade, podem ser opções de cultivo em áreas marginais de sequeiro em condições tropicais, visto que possuem alto teor de óleo com características propicias para o biodiesel, além de menor sensibilidade ao ambiente. Os objetivos deste trabalho foram caracterizar germoplasma de Brassica juncea L. e Brassica rapa L., avaliar o potencial produtivo e a divergência genética de acessos em Botucatu – SP, Brasil. Os experimentos tiveram início em outono-inverno de 2012, com a avaliação de 424 acessos de Brassica juncea L. e 209 de Brassica rapa L. quanto ao florescimento e produção de sementes. Em outono-inverno de 2015 e 2016 acessos de brássicas e um híbrido comercial da espécie Brassica napus L. foram avaliados, em experimentos em blocos ao acaso com três repetições, em relação aos componentes da produção, à produção grãos e óleo e a divergência genética. Do total de acessos introduzidos e avaliados, apenas 51 (12%) de Brassica juncea L. e 59 (28%) de Brassica rapa L. produziram sementes, devido ao efeito de fotoperiodo. Os componentes da produção variaram entre acessos e espécies, com destaque para precocidade e teor de óleo de acessos da espécie Brassica rapa L.; e o número de síliquas e a produtividade de grãos e óleo de acessos da espécie Brassica juncea L.. A produtividade de grãos e óleo foi em média 15% superior nos acessos de Brassica juncea L. em relação a espécie Brassica rapa L., com destaque para o acesso PI 180266 com 2056 kg ha–1 de grãos e 805 kg ha–1 de óleo. A variabilidade genética entre os acessos de brássicas possibilitou a formação de grupos de acessos para futuros ganhos em melhoramento genético. Conclui-se que os acessos selecionados confirmam a hipótese do potencial produtivo sem efeito de fotoperíodo em condições tropicais, o que demonstra que podem ser opções para cultivo em áreas onde a Brassica napus L. não está bem adaptada. / Brassica is the third largest source of vegetable oil in the world, with oilseeds grown in the Northern Hemisphere. In Brazil, despite the increase in recent years, Brassica napus L., is not a traditional crop due to limitations of photoperiod and high temperatures. Other species of the genus, such as Brassica juncea L. and Brassica rapa L., widely cultivated in low rainfall zones and fertility, may be cultivation options in marginal rainfed areas under tropical conditions, since they have high oil content with characteristics conducive to biodiesel, in addition to lower sensitivity to environment. The objectives of this work were to characterize the germplasm of Brassica juncea L. and Brassica rapa L. and to evaluate the productive potential, as well as the genetic divergence of accesses in Botucatu – SP, Brazil. The experiments started in autumn-winter of 2012, with the evaluation of 424 accessions of Brassica juncea L. and 209 of Brassica rapa L. regarding flowering and seed production. In the autumn-winter of 2015 and 2016, Brassica napus L. and commercial Brassica napus L. were evaluated in randomized blocks with three replicates, in relation to the production components, grain and oil production, and divergence genetic. Of the total number of accesses introduced and evaluated, only 51 (12%) of Brassica juncea L. and 59 (28%) of Brassica rapa L. produced seeds, due to the effect of photoperiod. The components of the production varied between accesses and species, with emphasis on precocity and oil content of Brassica rapa L.; and the growth and number of siliques of the specie Brassica juncea L. The yield of grains and oil was on average 15% higher in the accessions of Brassica juncea L. in relation to the species Brassica rapa L., with emphasis on access PI 180266 with 2056 kg ha–1 of grains and 805 kg ha–1 of oil yield. The genetic variability among the accessions of brassicas allowed the formation of groups of accessions for future gains in genetic improvement. It is concluded that the selected accessions confirm the hypothesis of the productive potential without photoperiod effect in tropical conditions, which demonstrates that they can be options for cultivation in areas where Brassica napus L. is not well adapted.

The soil inhabiting organism Plasmodiophora brassicae infects brassica crops causing millions of pounds of damage each year. The result of infection is extensive galling of the root system and eventually plant death. Current control measures are limited and the variability of the pathogen and its lifecycle makes finding new controls difficult. It was therefore considered that if several measures could be identified which reduced P. brassicae infection then they could be used in combination, reducing the possibility that the pathogen could evolve to overcome the controls. This research therefore aimed to find a set of control measures, and where possible a mode of action, which could be used in combination or alone to reduce P. brassicae infections. Calcium nitrate was identified as an effective control measure which affected several stages of P. brassicaes lifecycle (Fig :1) as well as the predominant pathogen race. The type of growth medium used was also found to affect the extent of infection and to influence the pathogen population. Soils from two areas were identified as suppressive to P. brassicae and the nature of their suppression was determined to be due to both biotic and abiotic factors. The identification of these suppressive soils may lead to the development of a bio-control or it may be possible to encourage these soils to develop in other areas. Some more "holistic" control measures were also investigated. Applications of calcified seaweed were found to be at least as effective in decreasing clubbing as calcium carbonate. Applications of chitin and seaweed extract however were found to have no effect on P. brassicae infection in this instance. The research within this thesis has identified several control measures and answered some questions about P. brassicae. It has however, also raised more questions and identified areas which require more research.

Hybrid development has become an essential component in many major crop species due to the exploitation of heterosis. However, parental combinations that exhibit high heterotic gains can be difficult to obtain if no prior genetic architecture is known. The current research focuses on heterotic gene pool development using genetic distance and multivariate cluster analysis. Seventy-nine inbred accessions were grouped using three different methods including; 1) phenotypic classification based on 20 qualitative and quantitative traits; 2) Sequence related amplified polymorphisms (SRAP) using 29 forward and reverse primer combinations; 3) genotyping-by-sequencing (GBS) using 80,005 single nucleotide polymorphisms. Both genotypic methods (SRAP and GBS) were compared to each other, and hierarchical clustering produced similar results with 68% homology between the two methods. Heterotic cluster accuracy was investigated between the two genotypic methods through hybrid performance. Forty-four hybrid combinations along with parental cultivars were grown at one location in Winnipeg, MB with three replicates in a randomized complete block design. Hybrid yield and heterosis were regressed against the genetic distance from each genotypic method. GBS was a better predictor of hybrids with high yield (R = 0.47, p <.01); however, SRAP was a better predictor for mid-parent and high-parent heterosis at R = 0.53 and R = 0.61, respectively. This research provides experimental evidence that SRAP and GBS heterotic pool definitions have utility in the prediction of high heterotic parental combinations / May 2016