عنوان مقاله [English]
In order to investigate the effect of water stress at heading stage on grain yield and yield components of eight wheat cultivars, in 2008 year a research was conducted in the two regions Esfahan and Ardestan by using split plot in a randomized complete block design with three replications which that two irrigation treatments included custom and late season water stress were main factor and 8 wheat varieties formed a subplot. In Esfahan region and adequate moisture conditions, SW-82-9 line and Pishtaz cultivars respectively with 10500, and 10630 kg ha-1 yields, had a significantly higher yield than other cultivars, but in water stress conditions, yield loss were respectively 8 and 14.9 percent. In water stress condition of Ardestan region, yield loss of SW-82-9 line and Pishtaz cultivars were 16.3 and 15.8 percent, respectively. In water stress condition of Esfahan and Ardestan regions, number of grains per spike and harvest index in SW-82-9 line were (33.8, 28.3) and (0.49, 0.44) respectively. Stress tolerance index range was 0.71 to 1.34 in Esfahan region and 0.56 to 1.22 in Ardestan area. According to the results of all three indicators, stress tolerance index, mean productivity and geometric mean of yield, SW-82-9 line could be produced grain yield similar to Pishtaz cultivars, and therefore had the potential to culture in both Isfahan and Ardestan regions.