Evaluation of Faba Bean Genotypes using Drought Tolerance Indices and Multivariate Statistical Methods

The present study was conducted to investigate the genetic diversity and evaluate the drought tolerance indices on 16 genotypes of faba been based on split plot design with three replications in Agricultural Research Center of Borujerd. Irrigation regimes as the including normal and drought stress levels and genotypes were considered as the main and sub plot,respectively. Analysis of variance for yield in normal conditions (N), yield under drought stress (S), and drought tolerance indices including tolerance index (TOL), mean productivity index (MP), harmonic mean index (HM), stress susceptibility index (SSI), geometric mean productivity index (GMP), mean productivity (MP) and modified stress tolerance index (K1STI) showed that the genotype effects for these parameters were significant (P≤0.01). Hence, genotype selection according to MP, GMP, TOL and HM indices led to selection of outstanding genotypes in two conditions (normal and stress). Cluster analysis of genotypes were divided into three groups. According to PCA analysis 73.2 % of data variations were justified by first component, and it had a high and positive correlation with grain yield in normal and stress conditions, MP, GMP, STT, K1STI, and HM, while there was a low and positive correlation with TOL and SSI. There is found that a positive and significant correlation for yield in normal condition with yield under drought stress and drought tolerance indices (p≤0.01). It had a maximum correlation with K1STI (r=0.995). GMP had a highest positive correlation with grain-yield in normal and stress conditions, therefore, it is considered as the more appropriate index. Results indicated that selection based on GMP, resulted in choosing the brilliant genotypes in normal and stress conditions.