RAPD markers linked to a block of genes conferring rust resistance to the common bean

Abstract

Rust, caused by the fungus Uromyces appendiculatus, may cause a significant loss to common bean (Phaseolus vulgaris L.) yield. RAPD markers tightly linked to the resistance genes may be used in breeding programs to aid the development of rust-resistant bean cultivars. In this sense, the objective of the present work was to identify RAPD markers linked to a rust resistance gene block present in the cultivar Ouro Negro. Two hundred and fourteen F2 individuals from a cross between the resistant cultivar Ouro Negro and the susceptible cultivar US Pinto 111 were inoculated with a mixture of eight races of U. appendiculatus. The segregation ratio obtained suggested that resistance is monogenic and dominant. Bulked segregant analysis was used in conjunction with the RAPD technique to search for markers linked to rust resistance genes. Two molecular markers flanking the rust resistance gene block were identified, one at 5.8 ± 1.6 cM (OX11(630)) and the other at 7.7 ± 1.7 cM (OF10(1,050)) of the gene. Simulated indirect selection efficiency in the F2 population using the two markers was 100%. The molecular markers identified in this work are currently being used for the selection of disease-resistant plants in the commom bean breeding program of the Federal University of Viçosa.<br>A ferrugem, causada pelo fungo Uromyces appendiculatus, pode ocasionar perdas significativas na produtividade do feijoeiro-comum (Phaseolus vulgaris L.). Marcadores RAPD fortemente ligados a genes de resistência à ferrugem podem ser usados em programas de melhoramento para auxiliar no desenvolvimento de cultivares resistentes. Nesse sentido, o objetivo do presente trabalho foi o de identificar marcadores RAPD ligados a um bloco de genes de resistência à ferrugem presente no cultivar Ouro Negro. Para isso, foram utilizados 214 indivíduos F2 originados do cruzamento Ouro Negro (resistente) x US Pinto 111 (suscetível universal). As plantas foram inoculadas com uma mistura de 8 raças de U. appendiculatus e a análise da segregação revelou uma herança monogênica dominante. Foi empregada a metodologia de bulk segregant analysis. Os bulks foram amplificados pela técnica de RAPD com 1280 primers. Foram encontrados dois marcadores flanqueando o bloco gênico que confere resistência à ferrugem: OX11(630) (5,8 ± 1,6 cM) e OF10(1050) (7,7 ± 1,7 cM). Considerando os indivíduos F2, a seleção indireta de plantas resistentes com base no uso dos dois marcadores simultaneamente leva a 100% de eficiência. Os marcadores identificados nesse trabalho estão sendo extremamente úteis no programa de melhoramento da Universidade Federal de Viçosa

Identification of RAPD markers linked to the rust (Uromyces fabae) resistance gene in pea (Pisum sativum)

“…The frequency of Ruf becoming unlinked to both these markers, therefore, would be only 2.1%. Use of flanking markers to improve the efficiency of indirect selection has been suggested earlier by Johnson et al (1995), Correa et al (2000) and Faleiro et al (2000) for rust (U. appendiculatus) resistance in P. vulgaris. Figure 4.…”

Genetic variability and pedigree analysis of Brazilian common bean elite genotypes

“…Lines (9) and (10) showed a genetic distance of zero, while line (1) presented a genetic distance of 0.06 in relation to lines (9) and (10) ( Table 3). These lines carries anthracnose and rust resistance genes, derived from the cultivar Honduras 35 known in Brazil as Ouro Negro (Faleiro et al, 2000; Alzate-Marin et al, 2001). Singh et al, (1991a), weight of 100 seeds in grams.…”

Identification of RAPD markers linked to the Uvf-1 gene conferring hypersensitive resistance against rust (Uromyces viciae-fabae) in Vicia faba L.

“…In addition to this, some factors as the inheritance type of the character under study, would determine the best method to optimize the process. In our case, due the monogenic inheritance of the Uvf-1 gene, we have used the BSA, first described by Michelmore et al (1991), to identify DNA markers closely linked to this resistance gene.To our knowledge, this is the first time that BSA has been used in faba bean breeding programs, although this strategy has been commonly used in other legume crops such as lentil (Eujayl et al 1998;Ford et al 1999;Chowdhury et al 2001), common bean (Olaya et al 1996;Young and Kelly 1997;Bai et al 1997;Alzate-Marín et al 1999;Park et al 1999;Faleiro et al 2000), pea (Timmerman et al 1994;Tiwari et al 1998) and soybean (Mian et al 1999). In all these cases, BSA allowed rapid mapping of monogenic resistance genes using segregating populations.…”