A comparison of the molecular organization of genomic regions associated with resistance to common bacterial blight in two Phaseolus vulgaris genotypes

Abstract

Resistance to common bacterial blight, caused by Xanthomonas axonopodis pv. phaseoli, in Phaseolus vulgaris is conditioned by several loci on different chromosomes. Previous studies with OAC-Rex, a CBB-resistant, white bean variety of Mesoamerican origin, identified two resistance loci associated with the molecular markers Pv-CTT001 and SU91, on chromosome 4 and 8, respectively. Resistance to CBB is assumed to be derived from an interspecific cross with Phaseolus acutifolius in the pedigree of OAC-Rex. Our current whole genome sequencing effort with OAC-Rex provided the opportunity to compare its genome in the regions associated with CBB resistance with the v1.0 release of the P. vulgaris line G19833, which is a large seeded bean of Andean origin, and (assumed to be) CBB susceptible. In addition, the genomic regions containing SAP6, a marker associated with P. vulgaris-derived CBB-resistance on chromosome 10, were compared. These analyses indicated that gene content was highly conserved between G19833 and OAC-Rex across the regions examined (>80%). However, fifty-nine genes unique to OAC Rex were identified, with resistance gene homologues making up the largest category (10 genes identified). Two unique genes in OAC-Rex located within the SU91 resistance QTL have homology to P. acutifolius ESTs and may be potential sources of CBB resistance. As the genomic sequence assembly of OAC-Rex is completed, we expect that further comparisons between it and the G19833 genome will lead to a greater understanding of CBB resistance in bean.

A New Common Bacterial Blight Resistance QTL in VAX 1 Common Bean and Interaction of the New QTL, SAP6, and SU91 with Bacterial Strains

“…Nonetheless, the physical map position for SNP47912 (40,517,575 bp) relative to SAP6 (39,938,699-39,939,569 bp;Perry et al, 2013) may guide further fine mapping of the region for development of a better marker for marker-assisted selection of the Pv10 QTL. Although, pooled mean scores for individuals with the SNP47912 marker were sometimes lower than those with the SAP6 marker, the mean differences were inconsistent and nonsignificant (data not shown).…”

In silico comparison of genomic regions containing genes coding for enzymes and transcription factors for the phenylpropanoid pathway in Phaseolus vulgaris L. and Glycine max L. Merr

“…Two mate pair libraries were prepared (50 bp read length) and sequenced using the Illumina HiSeq platform at the Center for Applied Genomics (Toronto, ON, Canada)]. Scaffolding and contig assembly were performed using SOAP2 de novo and ABYSS (Perry et al, 2013; DiNatale et al, unpublished). Currently, the OAC Rex genome is assembled into megabase contigs; pseudo-chromosome builds have been initiated and public release is expected to be in 2014.…”

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

“…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).…”

“…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).…”