Inheritance of Resistance to Bacterial Wilt in Common Beans
Document Type Article
Copyright by the Authors.
Bacterial wilt of common beans is an A2 quarantine pest disease caused by Curtobacterium flaccumfaciens pv. flaccumfaciens. Chemical, biological, and cultural control measures have not been efficient to mitigate the negative impact on yield caused by the disease. Thus, the resistance breeding strategy could be the most accurate. To determine the mode of inheritance for resistance to bacterial wilt, we evaluated five related generations of the cross between resistant G16829 and susceptible Raven. Initially, we identified an orange strain as highly pathogenic with a unique fingerprint. The fingerprinting was based on rep-PCR using ERIC and BOX primers. We inoculate five related generations with the orange strain and weekly evaluate the response of each plant. Results showed that all F1 plants and backcrosses to the susceptible parent were susceptible, demonstrating that susceptibility is dominant over resistance. The segregation ratio at F2 indicates that inhibitory epistasis causes the response to bacterial wilt. Therefore, bacterial wilt in common beans is a quantitative disease and epistasis is involved in the response to the pathogen, which is of interest especially for plant breeding of this trait.