Effect of Planting Dates, Salinity and Moisture Regimes on Root Anatomical Traits, Yield and other Traits of Wheat, Chamran Cultivar in Khuzestan

To investigate the effect of different planting dates (November 1-2018, December 1-2018 and December 31-2018) as the main factor, different salinity levels of the irrigation water (2, 7 and 12 dS/m) as the sub-plots factor and different irrigation regimes (including irrigation at 5 critical stages of the growth period, 2 stages of germination and flowering and 0 irrigation) as the sub-sub-plots factor with three replications a split-split plot experiment was carried out in a complete random blocks design during 2018-2019. Significant effects were observed for all treatments and interaction between two and three factors on grain yield and root anatomical traits (surfaces of the central cylinder, epidermis and cross-sectional). The highest and lowest grain yields (6106.30 and 689.30 kg/ha, respectively) belonged to planting at December 1-2018 and December 31-2018, salinities of 2 and 12 dS/m and also irrigation at 5 stages and no irrigation during the growing season. Other traits (number of spikes, number of grains, 1000-grain weight, spike length and plant height) were decreased with increasing in salt level and reducing irrigation events. Delayed planting reduced the yield and components more than early planting. The largest surface of ​​the central cylinder, and the cross-section was obtained with planting at December 1-2018 and the greatest epidermis surface was obtained with planting at December 31-2018. Grain yield had the highest positive and significant correlation with cross-sectional surface (0.396**) and it may be used as criteria for breeding wheat for an increased yield under unfavorable environments.