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Terminal and intermittent drought limits dry bean (Phaseolus vulgaris L.) production worldwide. Tolerance to drought exists but is difficult to breed for because of inconsistent expression across environments. Our objective was to identify quantitative trait loci (QTL) conditioning yield in a recombinant inbred line (RIL) population with consistent expression across multiple drought‐stress environments. We tested 140 RILs from ‘Buster’ pinto (susceptible)/‘Roza’ pink (tolerant) for yield under multiple stresses (intermittent drought, compaction, and low fertility) across 3 yr and terminal drought across four location‐years. A genetic linkage map (953 cM) was generated using single nucleotide polymorphism (SNP) markers. Two major‐effect QTL were detected on Pv01 and Pv02. The Pv01 QTL, defined by the closest marker SNP50809 (47.7 Mb), explained up to 37% of the phenotypic variance for seed yield under multiple stress (including intermittent drought) and was consistently expressed each year. The Pv02 QTL, nearest SNP40055 (11.8 Mb), was detected under drought stress (R2 = 33%) in addition to multiple stress (R2 = 17–23%). Phenological traits cosegregated with the yield QTL and affirmed the importance of phenological plasticity in adaptation to drought stress. Late maturity contributed to increased yield under multiple and nonstress and early maturity to increased yield under terminal drought. Given major and consistent effect, further investigation of the potential for the Pv01 and Pv02 QTL in breeding for multiple abiotic stress and drought tolerance in dry bean is warranted.

Common bacterial blight (CBB) is a severe disease in common bean (Phaseolus vulgaris L.). New resistance quantitative trait loci (QTL) should facilitate development of cultivars with high levels of resistance. Our objectives were to (i) identify new resistance QTL in VAX 1 and verify its presence in VAX 3, (ii) determine the interaction between QTL with existing SAP6 and SU91 QTL, and (iii) examine the interaction between QTL with less aggressive ARX8AC and aggressive Xcp25 bacterial strains. Sixty‐one F6:7 recombinant inbred lines (RIL) from ‘Othello’/VAX 1 and 100 RIL from Othello/VAX 3 were screened in the greenhouse. Disease severity of inoculated primary leaves, first and second trifoliolate leaves, and pods, was scored from 1 = no symptoms to 9 = completely diseased. Genotyping was performed using 5398 single nucleotide polymorphism (SNP) BeadChip and CBB resistance QTL‐linked sequence characterized amplified region (SCAR) markers, SAP6 and SU91. A novel resistance QTL with major effect was detected on Pv11 linkage group in Othello/VAX 1 and verified in Othello/VAX 3. This Pv11 QTL, defined by the closest marker SNP47467 (45,059,806 bp), explained 23% of the phenotypic variance for resistance in primary and 18% in trifoliolate leaves in Othello/VAX 1, and 13% and 22%, respectively, in Othello/VAX 3 to ARX8AC. The Pv11 QTL, named Xa11.4OV1,OV3, had greater influence against Xcp25, with respective values for variance for resistance explained in primary and trifoliolate leaves of 45% and 51% in Othello/VAX 1 and 26% and 37% in Othello/VAX 3. Conversely, SAP6 was only effective against ARX8AC in both populations, and surprisingly, SU91 was only effective against Xcp25 in Othello/VAX 3. SAP6 was the only QTL to condition resistance in pods. QTL interactions and differential reactions to strains indicate that the new Xa11.4OV1,OV3 QTL is critical in breeding for stable and higher levels of foliage resistance to CBB in common bean.

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Pseudomonas syringae pv. phaseoticola (Burkholder) Young et al. {Psp) causes halo blight, which is a serious bacterial disease of common bean {Phaseolus vulgaris L.). Several resistance (R) genes have been discovered in host differential cultivar ZAA 12. Our objectives were to further characterize and enable marker-assisted selection (MAS) of the Pse-2 gene in ZAA 12 purJDorted to have broad effect against multiple Psp races. A recombinant inbred population, ZAA 12 X 'Canadian Wonder', was challenged by the halo blight pathogen differential set consisting of nine Psp races. The resistance conferred by Pse-2 to races 2, 3, 4, 5, 7, 8, and 9 expanded the effect known for this gene from three to seven races. Segregation in Fg populations confirmed dominant inheritance for Pse-2 against all races except Race 8. Resistance to Race 8 was recessively inherited and most closely fit a 7 resistant to 9 susceptible segregation ratio in the Fg generation. Perhaps other genes are segregating that modify the effect of Pse-2 against Race 8. A sequence characterized amplified region (SCAR) marker tightly linked with Pse-2 was generated. The marker was used to integrate Pse-2 to chromosome 10. A survey of lines and cultivars revealed the SCAR will have broad utility for MAS of Pse-2.