Yield potential and stability of 10 Iranian bread wheat varieties and promising lines under different water stress conditions

This study was to test drought tolerance at the grain filling stage in wheat grain varieties with potential value to the bread industry. A field experiment was carried out at Miyandoab Agricultural and Natural Resources Research Station in 2008-9. The experiment was a strip plot arrangement in RCB design with four replications. The main plot contained different irrigation levels 70, 100, 130 and 160 mm of evaporation from class A pan, in each subplot were different wheat genotypes of Zarrin, Alvand, Shahriar, Sardari, C-81-10, C-81-4, C-81-14, C-83-3, C-83-8 and YET-84-9. Irrigation levels were applied at anthesis stage. Results showed that treatment of 160 mm compared to 70 mm, decreased days to maturity (6%), plant height (6%), number of spikes/ m2 (11%), number of grains/spike (13%), 1000 grain weight (22%), grain yield (29%) and harvest index (26%). Results showed that at irrigation levels of 70 and 100 mm evaporation, none of the varieties or potential products had greater grain yield than Zarrin. At 130 mm, genotypes C-81-10(5031 kg/ha), C-80-4(4762 kg/ha), C-83-8(4764 kg/ha) and YET-84-9(5202 kg/ha) had greater GY than Zarrin (4125kg/ha). At 160 mm the following yields were achieved; C-83-8(4755 kg/ha), YET-84-9(4919 kg/ha) and C-81-10(5341 kg/ha) had greater GY than Zarrin (3999 kg/ha) by 19, 23 and 34% respectively. Decreased growth period, grain weight, number of grains/spike and number of spikes per area unit were the main factors affecting grain yield loss in genotypes under drought stress conditions. Wheat grain varieties C-83-8, YET-84-9 and C-81-10 are recommended for cold regions that encounter drought stress in the grain filling period.