Drought resistance evaluation based on forage yield in accessions of Festuca arundinacea using drought resistance indices

Drought resistance of forage yield for 36 accessions of Festuca arundinacea were examined in randomized complete block design with three replications in both irrigated and rainfed environments. Significant variation (P<0.01) for forage dry matter yield was observed between the environments and genotypes. The results of mean comparisons showed that accessions 6 (Isfehan), 7 (Isfehan), 15 (Tavankesh), 25 (Australia), 26 (America) and 31 (Australia) had higher values for forage dry matter yield, in both environment conditions. Drought resistance indices of genotypes were measured for forage dry matter yield of two environment conditions including sensitivity to stress index (SSI), tolerance (TOL), mean productivity (MP), drought tolerant index (DTI), harmonic mean (MH) and geometrical mean of productivity (GMP). Variance analysis of drought resistance indices showed that accessions had significant variation (P<0.01). The first and second components from principal components analysis were accounted for 61.5 and 37.7 percent of variation among accessions for drought resistance indices, respectively. The indices of MP, DTI, MH and GMP as well as forage dry matter yield of stress and non-stress environments had the greatest share in first component. Also, these indices showed significant and positive correlation with forage dry matter yield of stress and non-stress environments, and based on the indices, the accession 6 (Esfahan), 7 (Esfahan), 31 (Australia) and 26 (America), showed the most resistance to drought stress. Our results were confirmed by cluster analysis.