Obtenção de SNPs, reação do feijoeiro comum à ferrugem da soja e piramidação de genes de resistência a Uromyces appendiculatus

• Ano de defesa: 2009
• Autor(a) principal: Souza, Thiago Lívio Pessoa Oliveira de
• Orientador(a): Barros, Everaldo Gonçalves de
• Banca de defesa: Paula Júnior, Trazilbo José de , Caixeta, Eveline Teixeira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Variações do genoma; Marcadores moleculares; Phakopsora pachyrhizi; Phaseolus vulgaris; Genes de resistência; Estudo de herança; Acasalamento; Uromyces appendiculatus; Seleção assistida por marcadores; Desempenho agronômico; Melhoramento de plantas
• Palavras-chave em Inglês: Genome variations; Molecular markers; Phakopsora pachyrhizi; Phaseolus vulgaris; Resistance genes; Inheritance study; Prebreeding; Uromyces appendiculatus; Marker-assisted selection; Agronomic performance; Plant breeding
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::GENETICA::GENETICA VEGETAL
• Link de acesso: http://locus.ufv.br/handle/123456789/1306

The present work reports results from researches developed at the Common Bean Breeding Program of the Federal University of Viçosa (UFV). It is composed by distinct sectors or sub-projects. We have decided to write it in the format of scientific papers; one of them is a paper review and the other four articles are original reports. They either have been submitted or will be submitted for publication in international refereed journals. For this reason, we have decided to write them in English, according to the Thesis and Dissertations Writing Standards from UFV. Abstracts of these articles containing their justifications, objectives, and main results are presented below: 1) Single nucleotide polymorphisms (SNPs) discovery in the common bean - SNPs were discovered in common bean (Phaseolus vulgaris L.) via resequencing of sequence-tagged sites (STSs) developed by PCR primers designed to soybean shotgun and BAC-end sequences, and to common bean genes and microsatellite flanking regions. DNA fragments harboring SNPs were identified in single amplicons from six contrasting P. vulgaris genotypes of the Andean ('Jalo EEP558', 'G19833', and 'AND277') and Mesoamerican ('BAT 93', 'DOR 364', and 'Rudá') gene pools. In the 131,120 bp of aligned sequence, a total of 677 SNPs were identified, including 555 single-base changes (295 transitions and 260 transversions) and 122 small nucleotide insertions/deletions (indels). The frequency of SNPs was 5.16 SNPs/Kb and the mean nucleotide diversity expressed as Halushka's theta was 0.00226. This work represents one of the pioneer efforts aiming to detect SNPs in P. vulgaris. 2) Resistance to soybean rust in the common bean - Soybean rust (SBR) incited by Phakopsora pachyrhizi has been reported in common bean cultivars. In this work a set of 44 P. vulgaris genotypes were tested for resistance to P. pachyrhizi including resistance sources to several fungal common bean diseases, carioca-type, black-type and red-type Brazilian commercial cultivars, and advanced lines developed by the BIOAGRO/UFV breeding program. Fourteen resistance sources to P. pachyrhizi were identified. 'PI 181996', 'Pérola', and 'Redlands Pioneer' presented the lowest mean scores of disease reaction. The inheritance of SBR resistance in 'PI181996' was studied and the results support the hypothesis that this resistance is monogenic and dominant. 3) Breeding for common bean rust resistance in the BIOAGRO/UFV, Brazil - Common bean is an economically, nutritionally, and socially important crop. Unfortunately, compared to other important grain legumes common bean yields are quite low. One of the several factors contributing to this situation is the high number of destructive diseases that attack P. vulgaris and cause serious damage to the crop. Among them is bean rust, incited by the highly variable fungus Uromyces appendiculatus. Bean rust control by plant resistance isan easy and economical strategy to be used in association to other rust management practices. This review presents an overview about the bean rust and reports some breeding initiatives aiming at the development of rust resistant cultivars in the BIOAGRO/UFV. 4) Characterization of the rust resistance gene present in the common bean cultivar 'Ouro Negro', the main rust resistance source used in Brazil - Identification and characterization of new resistance sources are basic steps for plant breeding programs aiming to develop modern cultivars with effective resistance to pathogens. The Mesoamerican black seeded common bean cultivar 'Ouro Negro' is the main rust resistance (RR) source used in Brazil, but its resistance gene (Ur-ON) has not been fully characterized yet. Here we have compared the RR spectrum presented by Ouro Negro with those of other bean lines harboring known RR genes when inoculated with nine races of U. appendiculatus. In addition, all bean lines were screened with molecular markers linked to Ur-ON aiming to identify additional evidence for the presence of alleles for this locus in the screened RR sources. Finally, we tested the allelic relationships of Ur-ON with already characterized RR genes from lines resistant to at least one race of the pathogen. We also accomplished allelism tests between 'Ouro Negro' and important RR sources in Brazil harboring unnamed RR genes. The results showed that the major dominant gene conditioning RR in 'Ouro Negro' is positioned at a locus distinct from those with which it was compared. 5) DNA marker-assisted breeding aiming rust resistance gene pyramiding in the common bean - In our common bean breeding program we used a gene pyramiding approach assisted by DNA markers aiming to develop bean lines with durable and ample resistance spectrum to rust. The RR genes Ur-5 (from 'Mexico 309'), Ur-11 (from 'BelMiDak RR-3'), and Ur-ON (from 'Vi-4899', a carioca seeded line derived from the cross 'Rudá' × 'Ouro Negro') were combined in the carioca-type bean cultivar 'Rudá'. Carioca seeded beans are the most consumed in the Brazilian market. We were able to select lines presenting all the DNA markers associated to the genes of interest and resistant to all of the specific isolates of U. appendiculatus which were tested. They were also resistant under field conditions. Yield evaluations show that these selected lines are as productive as the recurrent parent 'Rudá' and other high performance cultivars currently grown in Brazil.