Evaluation of drought tolerance in rice (Oryza sativa L.) cultivars and recombinant inbred lines

In order to study the adaptation of rice lines to drought stress and to identify the tolerant and sensitive lines, 150 pure lines in RIL population each derived from a cross between two Iranian rice varieties Gharib and Sepidroud were investigated. Augment design based on the randomized complete block design (RCBD) was used with 6 check cultivars and 4 replications in 2013-2014 growing season. In this study, based on correlation analysis geometric mean productivity (GMP), stress tolerance index (STI), mean harmonic (HM) and mean productivity (MP) were the most suitable indices for the selection of cultivars and lines under stress and non-stress conditions. The result of PCA showed that the first two PCs explained 98% of the total variance. Cluster analysis showed five distinct groups. In addition, according to results three-dimensional scatter plot and cluster analysis, Alikazemi, Gharib, Hashemi, Tarommahali, 1, 3, 7, 14, 22, 26, 27, 40, 49, 64, 65, 67, 68, 75, 98, 99, 120, 124, 126, 127, 133, 134, 138, 139, 141, 146, 147, 153, 157, 159, 162 and 163 were determined as the high yielding and the most tolerant cultivars and lines under drought stress condition which could be used in breeding programs.