New sources of nonspecific resistance to rust and common bacterial blight in dry bean landrace Pompadour

Abstract

Thirty four lines derived from a Pompadour landrace and three other lines from the Dominican Republic were co-inoculated with three cultures of Uromyces appendiculatus and three cultures of Xanthomonas campestris pv. phaseoli on separate leaves. The majority of the lines had dense trichomes (1–2 mm long) on the abaxial surfaces of upper leaves and developed small uredinia of moderate resistant rust reaction on the pubescent trifoliolate leaves and larger uredinia of moderate susceptible reaction on the primary glabrous leaves. Lines that lacked dense abaxial pubescence developed susceptible or moderate susceptible reactions on both primary and trifoliolate leaf stages. Differential reactions between strains of X. c phaseoli were observed on both leaf and pod infections and reactions on the leaf and on the pods were often different. Pompadour lines K, AE, R, and M had overall moderate resistance to three strains of X. c phaseoli and resistant or moderate resistance to three cultures of U. appendiculatus. These lines also have indeterminate growth habit associated with favorable and more stable seed yields and can now serve as valuable new germplasm sources for multiple disease resistance.