Molecular-marker-based genetic analysis of tepary bean-derived common bacterial blight resistance in different developmental stages of common bean.

摘要

RAPD molecular markers were used to construct a partial genetic linkage map in a recombinant inbred population derived from the common bean (Phaseolus vulgaris) cross PC50 X XAN159 for studying the genetics of bacterial disease resistance in commonbean. The linkage map spanned 426 cM and included 168 RAPD markers and 2 classical markers with 11 unassigned markers. The 70 recombinant inbred lines were evaluated for resistance to 2 strains of common bacterial blight (Xanthomonas campestris pv.phaseoli; Xcp). Common bacterial blight (CBB) resistance was evaluated for Xcp strain EK-11 in later-developed trifoliolate leaves, and for Xcp strains DR-7 and EK-11 in first trifoliolate leaves, seeds and pods. One to four quantitative trait loci accounted for 18 to 53% of the phenotypic variation for traits. Most significant effects for CBB resistance were associated with one chromosomal region on linkage group 5 and with 2 regions on linkage group 1, of the partial linkage map. The chromosomal region (a 13-cM interval) in linkage group 5 was significantly associated with resistance to Xcp strains DR-7 and EK-11 in leaves, pods and seeds. Regions in linkage group 1 were also significantly associated with resistance to both Xcp strains in more than one plant organ. In addition, a seed coat pattern gene (C) and a flower colour gene (vlae) were mapped in linkage groups 1 and 5, respectively, of the partial linkage map. The V locus was linked to a QTL with a major effect on CBB resistance.