Author(s): Damot Anteneh*, Firew Mekbib, Taye Tadesse and Yigzaw Dessalegn
Drought is one of the main factors limiting crop production in Ethiopia including finger millet in areas where low and erratic rainfall are common. The current study was aimed to identify drought tolerant and high yielding finger millet genotypes using drought tolerance indices. Two hundred and twenty five finger millet genotypes were evaluated in 15×15 simple lattice design with two replications at Werer Agricultural Research Center under moisture stressed and non-stressed conditions during the 2017/18 dry season. Grain yield data on moisture stressed and non-stressed treatments were used to calculate the following drought tolerance indices: drought susceptibility index (SSI), drought tolerance index (STI), geometric mean productivity (GMP), yield stability index (YSI), drought resistance index (DRI), mean productivity (MP), yield index (YI), harmonic mean (HM), stress susceptibility percentage index (SSPI) and abiotic tolerance index (ATI). Cluster, principal component and correlation analysis were computed. Genotypes Acc203401 and Acc203289 gave the highest grain yields under drought stress and nonstressed conditions, respectively. Based on the rank of genotypes using drought tolerant indices the highest grain yield was recorded for Acc203446. Positive and significant association of grain yield under both conditions was noted with SSI, YI, GMP, MP and HM suggested that these indices would be appropriate indices for screening high yielding and drought tolerant genotypes. The first two principal components (PCs) elucidated about 97.2% of the total variation. PC I, which explained about 56.1% of the total variation was due to YNS, YDS, YI, STI, GMP, MP, DRI and HM; whereas PC II described about 41.1% of the total variation, mainly due to YSI, SSI, TOL, RDI and RED. Biplot showed strong positive association among the indices DRI, YI, HM, GMP, STI and MP with grain yield under both moisture conditions. Cluster analysis classified the 225 finger millet genotypes into six clusters comprised of 1 to 70 genotypes. Generally, evaluation of genotypes using drought tolerance indices, which showed highly significant and positive association with grain yield under both moisture conditions, are reliable traits for further use in finger millet breeding program. Overall, Acc203399, Acc203401, Acc203414, Acc203423 and Acc203446 were genotypes, identified as drought tolerant, and YSI, STI, YI, GMP, GM, DRI and HM had strong and positive association with grain yield under moisture stressed condition and could be used as the most reliable indices for identifying tolerant finger millet genotypes.
