Genetics of common bean resistance to white mold

Abstract

The objective of the research was to investigate the nature and magnitude of the genetic factors involved in the resistance of the common bean to white mold. The lines G122 (resistant) and M20 (susceptible) were crossed to yield F1 and F2 generations and F2:3 progenies. The experiment was set up using the random block design with two replications, each of which was evaluated twice with fungal inoculations being performed on 28 and 38 day-old plants using the straw test method. Six to eight days after inoculation evaluations were conducted on individual plants and at the level of means of progenies using a diagrammatic scale ranging from 1 to 9. The additive-dominance model adopted was efficient, and the genetic control of resistance was predominantly due additive effects. Estimates of broad-sense heritability indicated that selection would be more efficient when based on the means of progenies and when successive inoculations are employed.