Evaluation of Drought Tolerance in Tef [Eragrostis Tef (Zucc.) Trotter] Genotypes Using Drought Tolerance Indices

Abstract

A field experiment was conducted to identify drought tolerant, high yielding and stable tef genotypes using drought tolerance indices. Sixty-four tef genotypes were evaluated under drought and non-stress conditions using “8 × 8 simple lattice design” with two replications at Debre-Zeit Agricultural Research Center. Drought tolerance indices including drought susceptibility index (SSI), drought tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), yield index (YI), yield stability index (YSI), drought resistance index (DRI), abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI), harmonic mean (HM) were estimated from grain yield under drought (Ys) and non-stress (Yp) conditions. Highest grain yields in both drought and normal watering conditions were recorded for genotype Melko. Based on drought tolerant indices the highest values of STI, GMP, and MP were related to genotypes Melko, Etsub, and Ziquala. Correlation analysis revealed that grain yield was positively and significantly correlated with STI, GMP, MP, YI, DRI, and HM, indicating that these indices were more important for screening stress-tolerant tef genotypes. Principal component analysis indicated that the first two components accounted for more than 98% of the total variations. The first PC contributed for 67.9% of the variation with strong presence of STI, GMP, MP, YI, DRI, HM, Ys, and Yp. Biplot analysis also indicated the STI, GMP, MP, YI, DRI, and HM were more reliable indices to identify drought tolerant tef genotypes. Cluster analysis grouped the 64 tef genotypes into seven clusters. The study showed that selection based on indices which exhibited significant and positive coordination with Ys and Yp are more reliable parameters for breeders to use in the tef improvement program.