Determination of terminal drought tolerant accessions in millet by drought tolerance indices

In order to compare the reaction of 13 millet accessions from gen bank collection to late season drought stress and with the aim of completion of gen bank information، specific assessments and determination of the best indices for drought tolerance، two separate experiments based on randomized complete block design with three replications were conducted at the Agricultural Research Center of Southern Khorasan during 2005 and 2006. The first experiment was conducted under normal irrigation and the second experiment was taken place under drought stress conditions (irrigation up to the 10% of panicle emergence). Experiment treatments included 13 millet accessions. Results showed that accessions number 15-143 (Southern Khorasan) and 15-24 (Yazd) had the highest two years average for grain and dry forage yields and number 15-132 (Hamadan) had the lowest grain yield among all accessions. Evaluation of accessions in terms of drought tolerance was made using MP، TOL، SSI، GMP، STI and HARM indices. HARM، GMP and STI were recognized as the best indices for severance of drought tolerant accessions according to the high correlation of these indices with grain and dry forage yields under stressed and non-stressed conditions. Based on using three dimensional graphics and accessions positioning on it، numbers 15-143 (Southern Khorasan)، 15-131 (Southern Khorasan) and 15-24 (Yazd) were identified as the most yielding and tolerant accessions to drought stress.