Evaluation of grain yield stability of new rapeseed (Brassica napus L.) lines under terminal drought stress conditions

To identify high yielding rapeseed lines with grain yield stablity under different moisture conditions, a field experiment was carried out consisting of 17 new rapeseed lines and two cultivars (Ahmadi and Opera). The genotypes were compared using randomized complete block design with three replications under three moisture conditions for two cropping seasons (2012-2013 and 2013-2014) at agricultural research station of Islamabad-e-Gharb, Kermanshah, Iran. Three irrigation regimes included; normal irrigation, no irrigation from flowering stage and no irrigation from silique stage. Considering significant year × genotype × irrigation regime interaction effect, some stability statistics was calculated for selection of high yielding lines with seed yield stability. Results showed that line L183 had the highest seed yield stability using different stability statistics. This line had 4129 kg.ha-1 seed yield. However, considering stability statistics such as superiority parameter and simultaneous selection methods for seed yield and stability, lines KS7 and KR4 with 4367 and 4346 kg.ha-1, respectively, were also identified as high yielding lines with seed yiled stability. New cultivar, Ahmadi, with 3600 kg.ha1 had the low environmental variance and coefficient of variation under different irrigation regimes, could be considered for being grown under terminal drought stress conditions.