Identification of black bean genotypes resistant to anthracnose and rust for Veracruz and Chiapas, Mexico

Abstract

Objective:to determine the reaction of 53 lines and three varieties of black beans to inoculation with Uromyces appendiculatusand Colletotrichum lindemuthianum, to identify genotypes resistant to rust and anthracnose. Design/methodology/approach:ten seedlings of each genotype were inoculated in the greenhouse with a suspension of U. appendiculatusurediospores and another 10 with a suspension of C. lindemuthianumconidia. Fourteen days after inoculation, the reaction of the genotypes to rust was evaluated with a severity scale of 1 to 6, and to anthracnose, with a scale of 0 to 4. The data were analyzed in a completely randomized design with 10 replications per treatment and for the separation of averages the LSD at 0.05 was applied. Results:41 genotypes showed a hypersensitivity reaction to rust, of which 25 had a reaction value of 2.0, statistically lower than that of the controls. In turn, 45 genotypes were resistant to anthracnose, of which 18 had a value of 1.0, statistically similar to that of Negro Jamapa and lower than that of the rest of the genotypes. Limitations of the study/implications:due to the diversity of races of both pathogens, the genotypes were inoculated with monopustular isolates of the main races of U. appendiculatusand with monosporic cultures of C. lindemuthianum, which occur in the bean crops of Veracruz and Chiapas.

Findings/conclusions:25 lines resistant to rust and 18 to anthracnose were identified, which stood out for presenting the least damage from these diseases.