Evaluation of drought tolerance indices in corn genotypes (zea mays l.)

In order to evaluate of six corn genotypes for drought stress tolerance an experiment was conducted under field conditions at Satloo station of agricultural research center of west Azerbaijan province in 2010-11 seasons. A strip plot experiment with the based on complete blocks design was carried out at four replications. Three drought stress levels including control, water held at flowering stage and ear emergence arranged as main plots and six genotypes single crosses of 704, 700, 640, 540, 500, and 260 were at subplots. Results analysis of variance showed that for traits of plant height, leaf area, ear length and diameter, grain per row, grain per ear, wood ear weight, 100-kernel weight, harvest index, total dry matter, grain yield and shoot weight under drought stress, genotypes and interaction between them were significantly differences (p≤0.05). Single crosses of 640 and 704 with 3458 and 3442g/m2 grain yield at well-watered had the highest amounts and single crosses of 500 and 700 with 1430 and 1406g/m2 at drought stress of flowering stage were the lowest values. Indices of STI, GMP, MP, and HAR identified genotypes of 640, 540 with 1917 and 2162g/m2 grain yield as tolerant, and single cross 700 with 1512g/m2 as a sensitive genotype. HAR index had significant positive correlation with grain yield under drought stress (r=0.91**) and it was the best index for identifying drought tolerance genotypes. Principal component analysis showed that two first components explained more than 95% of variations. Also MP and TOL indices with 82% and 77% had the highest coefficients at the first and second components, respectively.