Effect of seed priming on seedling growth and grain yield of bread wheat (Triticum aestivum L.) cultivars in sowing datw treatments

To evaluate germination and grain yield of three spring bread wheat cultivars affected by seed hydropriming and sowing date, three experiments were conducted. In the first experiment, effect of 7 hydropriming durations (0, 6, 8, 10, 12, 14 and 16 h) was examined on germination and seedling growth of Star, Chamran and Fong cultivars. In the second experiment, some biochemical traits and enzyme activities were measured in the primed seeds for 6, 8 and 10 h hydropriming durations. Effect of three sowing dates (12 Nov., 10 Dec. and 7 Jan.). hydropriming and control treatments on grain yield of wheat cultivars was researched in third experiment which was carried out as factorial arrangement in randomized complete block design with three replications in the research field of Faculty of Agriculture, Shahid Chamran University of Ahvaz, during 2014-2015 growing season. Results of the first experiment showed that hydropriming with 8 h imbibition had the most positive effect on seed vigor of bread wheat cultivars. Results of the second experiment showed that with increasing hydropriming duration to 10 h, α amylase enzyme activity and of soluble carbohydrates and proteins contents in seeds increased, also higher malondialdehyde content and insufficient antioxidant enzyme activities (enzyme activity was not increased or reduced by following imbibition to 10h) in 10 h when compared with 8 h hydropriming duration was observed. In this research, Relationship between antioxidant enzyme activities with germination and seedling growth were positive and significant. Results of the field experiment showed that hydropriming treatments significantly improved seedling emergence, by 2.3%, and reduced average emerging time by 1.4 days as compared with control. The sowing date× cultivar interaction effect indicated that delayed sowing had the highest and lowest effect on star and fong cultivars, respectively. Average grain yield significantly increased, by 7%. in hydropriming treatment in comparison to control. Also application of seed hydropriming with suitable soaking duration improved seed emergence in delayed sowing dates.