RESPONSE OF COMMON BEAN GENOTYPES TO LESS-AGGRESSIVE AND AGGRESSIVE STRAINS OF XANTHOMONAS CAMPESTRIS PV. PHASEOLI CAUSING COMMON BACTERIAL BLIGHT

摘要

Common bacterial blight caused by Xanthomonas campestris pv. phaseoli is an important seed-transmitted disease worldwide. Low levels of resistance occur in common bean landraces from Mexico, and Phaseolus coccineus has an intermediate level of resistance. The tepary bean (P. acutifolius) and the derived interspecific breeding lines have the highest levels of resistance (Singh and Munoz, 1999). Lema et al. (2007) reported significant differences among common bean genotypes, and bacterial isolates anddensities. Duncan et al. (2011) observed interaction between common bean genotypes and bacterial strains but, without any crossovers. The objectives of this study were to: (i) determine the response of common bean genotypes to less-aggressive and aggressive strains of X. campestris pv. phaseoli, and (ii) assess the effects of bacterial densities.