Reaction of some common bean cultivars and genotypes to Fusarium solani f. sp. phaseoli with and without drought stress under greenhouse conditions

Fusarium root rot of common bean, caused by Fusarium solani f. sp. phaseoli (Fsp), is a major disease of this crop in Iran. In this study 13 commercial cultivars and genotypes in 3 types of common bean were evaluated for resistance to Fusarium root rot under greenhouse conditions. The investigation was conducted as a factorial experiment in a completely randomized design with three replications under conditions with and without drought stress. The reaction of cultivars and genotypes were evaluated based on measuring disease severity (root necrosis) and some growth parameters. Results showed a significant difference in yield components of different cultivars and the impact of Fsp on evaluated parameters. Cultivars in response to Fsp without drought stress were divided into three groups: 1. Weak infection: Sadri, Joneghan, Kosha, Sayad, 2. Moderate infection: Talash, Akhtar, D81083, Ghafar, Lordegan, Dorsa and 3. Severe infection: Pak, Shekofa, Daneshkadeh. Generally, the most, moderate and least sensitive varieties were belonged to white bean, pinto (Chiti) bean and red kidney bean cultivars, respectively. Under drought stress conditions except for Sadri and Sayad which showed moderate of disease severity, other cultivars showed severe infection resulting in plant death. These results indicated that drought stress is a predisposing factor in pathogenicity of Fsp on common bean.