Sequence Characterized Amplified Regions Linked to Rust Resistance Genes in the Common Bean

Abstract

to multiple races of U. appendiculatus, indicating that they are organized in clusters of race-specific genes.Uromyces appendiculatus (Pers.) Unger, the causative fungus of DNA amplification of near isogenic lines (NILs) rust in common beans (Phaseolus vulgaris L.), consists of many patho- Martin et al., 1991) or of contrasting types or pathogenic races. Cultivar Ouro Negro is resistant to most DNA bulks from segregating populations (Michelmore pathotypes detected in Brazil in the last few decades. We attempted et al., 1991) can be used to detect RAPD (Williams et to identify molecular markers linked to a rust resistance gene block present in Ouro Negro. DNA samples extracted from homozygous al., 1990; Welsh and McClelland, 1990) markers in close near isogenic BC 3 F 2:3 lines derived from a cross between susceptible proximity to disease resistance genes. During the develcultivar US Pinto 111 and Ouro Negro were grouped, following greenopment of NILs, these two strategies can be combined house inoculations, into two contrasting bulks, one containing only by constructing DNA bulks from BC n F 2:3 individuals resistant and the other only susceptible plants. The bulks were amplifrom each of two contrasting NILs. This method infied with 605 random primers and two of them amplified bands which creases the chance that markers will be identified close were heteromorphic between the two bulks. These random amplified to the gene of interest (Michelmore et al., 1991; Haley polymorphic DNA (RAPD) bands were transformed into sequence Miklas et al., 1993). characterized amplified regions (SCARs) SCARBA08 and SCARF10. Several RAPD markers associated with genes confer-The rust resistance-susceptibility phenotypes and the molecular genoring resistance to rust in common bean have been identitypes with the two SCAR markers of 303 F 2:3 families from US Pinto fied Haley et al., 1993.; Johnson et 111 ϫ Ouro Negro were determined. SCARBA08 and SCARF10 were determined to be 4.3 Ϯ 1.2 and 6.0 Ϯ 1.3 centimorgans (cM) al., 1995). In some cases, the application of these markfrom the rust resistance locus, respectively. These markers are being ers has been restricted to the laboratories where they used in combination with other markers for resistance to rust, anthracwere identified because of reproducibility problems nose, and angular leaf spot previously identified in our laboratory to

Characterization of the Angular Leaf Spot Resistance Gene Present in Common Bean Cultivar Ouro Negro

“…To ensure that the F 1 seeds were true hybrids, we analyzed the color, shape, size and brightness of the corresponding F 2 seeds. In the case of the cross between 'Ouro Negro' and 'Cornell 49-242', which are phenotypically very similar, the F 1 seeds were submitted to a molecular analysis with marker SF10 1050a (Corrêa et al, 2000) according to a procedure described by Alzate-Marin et al (1996). The F 2 segregating populations were used in artificial inoculations.…”

Tagging and mapping of genes and QTL and molecular marker-assisted selection for traits of economic importance in bean and cowpea

“…1). Unnamed genes from Dorado and Ouro Negro (Corrêa et al, 2000) map near Ur-5 on LG B4 (Miklas et al, 2000a,b). The Ur-3 and Ur-11 genes and an unnamed rust resistance gene from Dorado (Miklas et al, 2000a) map toward the end of B11, distally located from the Co-2 locus.…”

“…A repulsion linkage between QTL affecting BGMV and CBB resistance was observed on LG B7, which partially explained the low, but consistent, negative phenotypic correlation ðr ¼ À0:23Þ observed between those two traits in the Dorado  XAN176 population . Ur-5, unnamed rust resistance genes from Dorado and Ouro Negro (Corrêa et al, 2000), Co-9 and Co-10 (Geffroy et al, 1999;AlzateMarin et al, 2003), and QTL conditioning resistance to BGMV and Macrophomina all map to a common region on B4 (Miklas et al, 2000a; Fig. 1 and Table 2).…”

Common bean germplasm resistant to races 73 and 2047 of Colletotrichum lindemuthianum

“…All amplification reactions were performed with a thermal cycler (MJ Research Inc., Waltham, MA). The polymerase chain reaction (PCR) program for SF101072 consisted of 3 min at 94°C, 35 cycles of 15 s at 94°C, 1 min at 65°C, and 90 s at 72°C, followed by a 7 min extension at 72°C and 4 min at 4°C (Corrêa et al, 2000). PCRs were performed in 25 µL total reaction volumes containing 40 ng total DNA; 0.2 mM each dNTP; standard …”