Progress in Breeding Andean Common Bean for Resistance to Common Bacterial Blight

Abstract

Common bacterial blight is a severe disease of common bean (Phaseolus vulgaris L.) worldwide. Use of resistant cultivars is crucial for its control. The objectives were to (i) assess the progress made in breeding large‐seeded Andean bean developed between 1974 and 2010 and (ii) determine their resistance‐linked sequence characterized amplified region (SCAR) marker composition. Ten Andean and four Middle American common bacterial blight resistant beans including checks were evaluated in the greenhouse in 2011. Bacterial strains ARX8AC and Xcp25 were used to inoculate primary and trifoliolate leaves. The mean disease score of the trifoliolate was 5.0 and of the primary leaf was 2.8. Strain Xcp25 had a mean score of 3.8 in primary and 5.9 in trifoliolate leaves. The respective scores for ARX8AC were 1.9 and 4.2. Andean ‘Montcalm’, with the SAP6 quantitative trait loci (QTL) and USDK‐CBB‐15, and USWK‐CBB‐17, with the SAP6 and SU91 QTL, showed an intermediate response to ARX8AC and a susceptible response to Xcp25. Middle American VAX 1 with SAP6, Andeans 08SH‐840 and CXR 1 with SAP6 and SU91, and RCS52‐2, RCS53‐3, and RCS63‐5B with SU91 and BC420 were resistant or intermediate to both strains. Middle American VAX 3 and VAX 6, with SAP6 and SU91, had the highest levels of resistance to ARX8AC, but their responses to Xcp25 were similar to the latter Andean group. Thus, significant improvement has been achieved, but breeding for yet higher levels of resistance, recovery of commercial seed types, and improving yield and other agronomic traits should be emphasized.

Impact of common bacterial blight on the yield, seed weight and seed discoloration of different market classes of dry beans (Phaseolus vulgarisL.)

“…Each genotype was tested by PCR for the presence of the SCAR markers BC420, SAP6 and SU91 (Yu et al 2004;Duncan et al 2012;Viteri et al 2014) and the SSR marker PVctt001 (Yu et al 2000b;Michaels et al 2006), which are associated with resistance to CBB. DNA extraction and PCR assays were conducted as previously described by Boersma et al (2013).…”

“…However, Duncan et al (2012) determined that under severe disease pressure, SU91 alone did not provide high levels of CBB resistance and the combination of SU91 and BC420 was associated with high levels of CBB resistance. Viteri et al (2014) reported that certain bean cultivars which possessed the SCAR marker SU91 for CBB resistance displayed intermediate levels of CBB resistance and therefore they recommended pyramiding QTLs for resistance. However in the current study, the presence of both SU91 and BC420 along with SAP6 did not prevent substantial yield losses in HR67 caused by CBB.…”

“…phaseoli produced no evidence of the existence of different races in Canada (Bett and Banniza 2014). Common bacterial blight resistance is inherited quantitatively, with a few major genes (Yu et al 2004;Liu et al 2008), but also with epistatic effects of low to moderately high heritability (Vandemark et al 2008;Perry et al 2013;Viteri et al 2014). As many as 22 minor-and major-effect QTLs conferring resistance to CBB have been reported, which are distributed on all 11 chromosomes (Singh and Schwartz 2010).…”

“…Two other QTLs located on linkage groups Pv06 and Pv08 were introgressed from tepary bean (P. acutifolius A. Gray) and are associated with markers BC420 and SU91, respectively (Yu et al 2004;Viteri et al 2014). The expression of the Sequence Characterized Amplified Region (SCAR) marker SAP6 is epistatic to that of BC420 (Vandemark et al 2008).…”

“…In recent years a number of cultivars and breeding lines with moderate to high levels of resistance to CBB have been developed in North America, the most resistant lines being those that carry QTLs from the tepary bean (Miklas et al 2003;Liu et al 2008;Duncan et al 2012;Perry et al 2013;Viteri et al 2014). HR67 is one such navy bean germplasm line, developed by Agriculture and Agri-Food Canada at Harrow (Park et al 2007a).…”