Fontes de resistência à mancha-angular do feijoeiro-comum no Brasil

Abstract

The objective of this study was to evaluate the resistance of bean genotypes to different races of Phaeoisariopsis griseola present in Brazil, by studying the reaction of nine potentially resistant bean sources (MAR 1, MAR 2, MAR 3, AND 277, G 5686, BAT 332, Cornell 49-242 and Mexico 54) inoculated with 61 fungus isolates and characterized in 25 pathotypes. The first trifoliate leaf of each plant was inoculated with a 2 x 104 spores/ml suspension. Plants were maintained at 20-22 ºC and 95 % relative humidity for 48 hours. The evaluations were carried out 15 days after inoculation. The variety Mexico 54 presented & resistance reaction to 20 races thus being considered the best resistance source tested. tIhe varieties AND 277, MAR 2, Cornell 49-242, G5686 and BAT 332 were resistant to 17, 16, 12, 13 and 10 races, respectively. "Ihe Rudá variety was susceptible to most races. These results demonstrated the need to introduce more resistance genes to angular leaf spot in commercial varieties.