Variabilidade de isolados de Xanthomonas campestris pv. phaseoli quanto a patogenicidade em cultivares de Phaseolus vulgaris.

Fifteen isolates of X. campestris pv. phaseoli (Xp) from 7 Brazilian states were compared with the standard isolate Xp CNF 15 with regard to pathogenicity to 5 common bean cultivars. Highly significant differences were observed among cultivars and isolates in relation to resistance and pathogenicity, respectively. Resistant cultivars exhibited approximately half the disease intensity of susceptible cultivars. Isolate Xp CNF 28, characterized by a high degree of pathogenicity, was suggested as a new standard isolate to replace Xp CNF 15