Variability for angular leaf spot and anthracnose resistance among common bean progenies with different levels of endogamy

Abstract

This study aimed at evaluating the variability in resistance of common bean progenies and plants to diseases caused by Pseudocercospora griseola and Colletotrichum lindemuthianum. It also sought to infer whether S0 plants were heterozygous for the possible resistance loci and the frequency resistant plants varies with the bulk opening generation. Progenies from the fourteenth yield recurrent selection cycle were used. One hundred S2:7 and one hundred S5:9 progenies derived from ten S0:2 plants were evaluated. Seedlings were inoculated separately with the 63–63 race of P. griseola and race 65 of C.lindemuthianum. Variance analyses were conducted for disease severity scores and both the genotypic and phenotypic parameters were estimated. The progenies showed variable resistance levels to the disease caused by both pathogens. Such variability was detected among plants of the population and among descendants of some S0 plants, thus suggesting that they were likely heterozygous for the resistance loci. The frequency of resistant progenies/plants in the population was high, even though the selection was not specific these pathogens. The time of bulk opening did not significantly affect the reaction to the disease by both pathogen. This information is useful for future recurrent selection cycles.