Quantitative Trait Loci Associated with Bacterial Brown Spot in Phaseolus vulgaris L
Navarro, F. | Skroch, P. | Jung, G. | Nienhuis, J.
Bacterial brown spot (BBS) is caused by Pseudomonas syringae pv. syringae, an epiphytic, ice nucleation active bacterium and a pathogen of many crop species. In snap bean (Phaseolus vulgaris L.), BBS reduces crop value due to blemishes on the pods. A recombinant inbred line population (EP-RIL) and an inbred backcross population (EEP-IBC) developed from crosses between a BBS-resistant landrace, Puebla 152, and a susceptible cultivar, Eagle, were tested for ice nucleation and number of BBS lesions. The rank correlation between leaf ice nucleation and number of BBS lesions was 0.65. Regions located on linkage groups B1, B3, B6, and B11 were associated with quantitative trait loci (QTL) for both resistance traits in the EP-RIL by composite interval mapping. Random amplified polymorphic DNA (RAPD) marker P1.1500 located on linkage group B1, and AN6.1600 located linkage group B6, were confirmed in the EEP-IBC population. These regions explained 13 and 19% of the variation for BBS in the EP-RIL population. The region from linkage group B3 was not confirmed in the EEP-IBC population, but was significantly associated with BBS resistance in an independent population in a previous study. The results indicate that indirect selection for RAPD markers associated with QTL can be effective in introgressing BBS resistance.Show more [+] Less [-]