Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11847
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Item Genetic distances in soybean based on RAPD markers(Bragantia, 1999) Corrêa, Ronan Xavier; Abdelnoor, Ricardo Vilela; Faleiro, Fábio Gelape; Cruz, Cosme Damião; Moreira, Maurilio Alves; Barros, Everaldo Gonçalves DeFour methods were applied to determine pairwise genetic distances among five soybean genotypes which are potential genitors for a mapping population. Additionally, individual plants from the most divergent pair of genotypes were evaluated by the RAPD technique to determine their degree of homozygosity. Genetic distances based on RAPD data were calculated by the modified Rogers' distance, and also by the following arithmetical complements of similarity: simple match, Nei and Li, and Gower. These genetic distances were similar, presenting a correlation coefficient ranging from 0.99 to 1.00. In all four methods lines UFV 91-717 and Ichigowase were the most divergent ones (4.53 to 21.43%). DNA samples from five plants from each of the two most divergent genotypes were amplified with 28 different primers. Among the amplified products, only five were polymorphic in each group (2.10%), demonstrating their high intragroup degree of homozygosity. These homozygosity were maintained when DNA samples from 12 plants from each of the two most divergent genotypes were amplified. These parameters were extremely useful for the confirmation of the chosen pair of genitors to generate a mapping population.Item Sequence characterized amplified regions linked to rust resistance genes in the common bean(Crop Science, 2000-05) Corrêa, Ronan Xavier; Costa, M. R.; Good- God, P. I.; Ragagnin, V. A.; Faleiro, F. G.; Moreira, M. A.; Barros, E. G. deUromyces appendiculatus (Pers.) Unger, the causative fungus of rust in common beans (Phaseolus vulgaris L.), consists of many pathotypes or pathogenic races. Cultivar Ouro Negro is resistant to most pathotypes detected in Brazil in the last few decades. We attempted to identify molecular markers linked to a rust resistance gene block present in Ouro Negro. DNA samples extracted from homozygous near isogenic BC3F2:3 lines derived from a cross between susceptible cultivar US Pinto 111 and Ouro Negro were grouped, following greenhouse inoculations, into two contrasting bulks, one containing only resistant and the other only susceptible plants. The bulks were amplified with 605 random primers and two of them amplified bands which were heteromorphic between the two bulks. These random amplified polymorphic DNA (RAPD) bands were transformed into sequence characterized amplified regions (SCARs) SCARBA08 and SCARF10. The rust resistance–susceptibility phenotypes and the molecular genotypes with the two SCAR markers of 303 F2:3 families from US Pinto 111 × Ouro Negro were determined. SCARBA08 and SCARF10 were determined to be 4.3 ± 1.2 and 6.0 ± 1.3 centimorgans (cM) from the rust resistance locus, respectively. These markers are being used in combination with other markers for resistance to rust, anthracnose, and angular leaf spot previously identified in our laboratory to aid the indirect selection of desirable plants in segregating populations in which Ouro Negro has been used as donor parent.Item Ligação gênica da resistência à ferrugem e à antracnose na variedade de feijão ouro negro(Revista Ceres, 2000-07) Moreira, Maurílio Alves; Ragagnin, Vilmar Antônio; Corrêa, Ronan Xavier; Vinhadelli, Wender Santos; Barros, Everaldo Gonçalves de; Faleiro, Fábio GelapeA variedade Ouro Negro tem sido utilizada no Programa de Melhoramento do Feijoeiro (Phaseolus vulgaris L.) da UFV/BIOAGRO/EPAMIG como fonte de genes de resistência à ferrugem e à antracnose. Para melhor entendimento da herança e da organização desses genes de resistência, foi analisada a segregação de 231 plantas RC3F2 com relação à resistência a essas duas doenças. As plantas RC3F2, com aproximadamente 10 dias, foram inoculadas com uma mistura de uredosporos de Uromyces appendiculatus var appendiculatus coletados em diferentes municípios de Minas Gerais Após a avaliação da resistência à ferrugem, as mesmas plantas RC3F2 foram inoculadas com a raça 89 de Colletotrichum lindemuthiamun. A análise dos sintomas evidenciou que tanto a resistência à ferrugem quanto à antracnose são controladas por fatores dominantes únicos. Foi também observado que os genes de resistência à ferrugem e à antracnose presentes Ouro Negro estão ligados entre si. Para melhor entendimento da organização genômica de tais genes, estão sendo realizados, nos laboratórios do BIOAGRO-UFV, trabalhos mais detalhados envolvendo marcadores moleculares e populações segregantes adequadas.