EVALUATING THE WATERLOGGING TOLERANCE OF FABA BEAN GENOTYPES AT DIFFERENT GROWTH STAGES UNDER FIELD CONDITIONS

Waterlogging stress is one of the most important abiotic stresses in Mediterranean conditions such as north of Iran. The tolerance of faba bean to waterlogging may vary between genotypes. This study investigated the effects of 10 days of waterlogging on grain yield for 21 faba bean genotypes at two stages (flowering and pod-filling stages) during 2016-2017 and 2017-2018 under farm conditions. A randomized complete block design with three replications was used at three field sites (normal and waterlogging sites). Nine indices of endurance were calculated in normal and waterlogging conditions. The results indicated that waterlogging stress reduced the faba bean grain yield. Also, the negative waterlogging effect at flowering stage is more than pod-filling stage. Correlation coefficients and principal component analysis (PCA) results revealed that mean productivity (MP), geometric mean productivity (GMP), harmonic mean (HM), and stress tolerance index (STI) indices could be effectively used for screening of waterlogging stress tolerant genotypes. Waterlogging was caused to decrease significantly grain yield in all genotypes. According to results of three-dimensional graphs the genotypes G21, G18, G15, G6 and G2 with an average yield 4806, 4815, 4789, 4686 and 4681 kg.ha-1, respectively, were selected as waterlogging stress tolerance and suitable grain yield under non-stress and waterlogging stress (waterlogging stress in flowering and pod-filling stages) conditions. Therefore, these genotypes can be used as source of genes in faba bean breeding programs to obtain tolerant cultivars and cultivation in the areas under waterlogging stress.