Navegando por Autor "Costa, M. R."
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Item Development and agronomic performance of common bean lines simultaneously resistant to anthracnose, angular leaf spot and rust(Plant Breeding, 2009-04-01) Ragagnin, V. A.; Souza, T. L. P. O. de; Sanglard, D. A.; Arruda, K. M. A.; Costa, M. R.; Alzate‐ Marin, A. L.; Carneiro, J. E. de S.; Moreira, M. A.; Barros, E. G. deThe common bean is affected by several pathogens that can cause severe yield losses. Here we report the introgression of resistance genes to anthracnose, angular leaf spot and rust in the ‘carioca‐type’ bean cultivar ‘Rudá’. Initially, four backcross (BC) lines were obtained using ‘TO’, ‘AB 136′, ‘Ouro Negro’ and ‘AND 277’ as donor parents. Molecular fingerprinting was used to select the lines genetically closer to the recurrent parent. The relative genetic distances between ‘Rudá’ and the BC lines varied between 0.0% and 1.99%. The BC lines were intercrossed and molecular markers linked to the resistance genes were used to identify the plants containing the genes of interest. These plants were selfed to obtain the F2, F3 and F4 plants which were selected based on the presence of the molecular markers mentioned and resistance was confirmed in the F4 generation by inoculation. Four F4:7 pyramid lines with all the resistance genes showed resistance spectra equivalent to those of their respective donor parents. Yield tests showed that these lines are as productive as the best ‘carioca‐type’ cultivars.Item Development and characterization of common black bean lines resistant to anthracnose, rust and angular leaf spot in Brazil(Euphytica, 2010-05-26) Moreira, M. A.; Costa, M. R.; Arruda, K. M. A.; Carneiro, J. E. S.; Moreira, M. A.; Barros, E. G.Anthracnose, rust and angular leaf spot caused by Colletotrichum lindemuthianum, Uromyces appendiculatus and Pseudocercospora griseola, respectively, are economically important diseases affecting the common bean production in Brazil. The BIOAGRO/UFV bean breeding program developed Rudá-R, a dry bean line with ‘carioca’ seed type, containing the following disease resistance genes: Co-4, Co-6 and Co-10 (anthracnose); Ur-ON (rust) and Phg-1 (angular leaf spot). To transfer this combination of disease resistance genes present in Rudá-R to a black-seeded bean, a backcrossing program aided by molecular markers was conducted, involving Rudá-R (donor genitor) and Diamante Negro (recurrent genitor). Forty black-seeded BC3F3:6 lines were obtained with combinations of at least three markers linked to the indicated disease resistance genes. The lines were evaluated for resistance to the three mentioned pathogens. Eight of the lines were homozygous and resistant to all four evaluated races of C. lindemuthianum, but susceptible to race 2047. Four of the lines were homozygous and resistant to two races of U. appendiculatus. Twenty of the lines were homozygous and resistant to the two races of P. griseola tested. Grain yield of the BC3F3:6 lines was evaluated during the ‘winter’ season of 2006 and the ‘dry’ season of 2007. All lines had statistically equal or higher yields than Rudá-R and Diamante Negro. Lines were identified that not only were high yielding but also resistant to the three pathogens tested. These lines are potential genotypes for further testing and for release as new black common bean varieties.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.