Resistance of common bean (Phaseolus vulgaris L.) cultivars and germplasm lines to the purple variant of bacterial wilt (Curtobacterium flaccumfaciens pv. flaccumfaciens).
A growth cabinet study was conducted to determine the resistance reaction of 14 common bean cultivars and lines, namely AC Black Diamond, L02F132, UI906, AC Resolute, AC Polaris, US1140, Viva, AC Agrinto, Othello, AC Redbond, and NW63, to the purple variant of Curtobacterium flaccumfaciens pv. flaccumfaciens, the causal agent of bacterial wilt of bean. Results of hilum injury/seed inoculation tests revealed significant (P<0.05) differences in disease severity index (DSI) among the cultivars and lines after 14 days of incubation. The great northern cultivar AC Resolute, the pinto cultivar AC Agrinto, the black germplasm line L02F132, and the pink cultivar AC Early Rose, were identified as resistant to the purple variant of the bacterial wilt pathogen, based on the results of least significant difference (LSD) analyses. The study determined that germplasms resistant to the purple variant of C. flaccumfaciens pv. flaccumfaciens were also generally resistant to the yellow and orange variants of the bacterial wilt pathogen, as shown in a previous study. This study concludes that these bacterial wilt-resistant germplasm lines are an important resource for breeding and developing new bean cultivars for combined resistance to all three variants of C. flaccumfaciens pv. flaccumfaciens.