Effect of seed priming and application of cytokinin and auxin on growth and grain yield of wheat (Triticum aestivum L.) under Ahvaz climatic conditions

N. Khamdi, M. Nabipour, H. Roshanfekr, and A. Rahnama. 2019. Effect of seed priming and application of cytokinin and auxin on growth and grain yield of wheat (Triticum aestivum L.) under Ahavz climatic conditions. Iranian Journal of Crop Sciences. 21(1): 31-44(In Persian). To evaluate the effect of seed priming and application of cytokinin and auxin on grain yield wheat cv. Chamran, an experiment was carried out in Faculty of Agriculture, Shahid Chamran University of Ahvaz, Iran, in 2015-16 and 2016-17 growing seasons. This experiment was carried out as factorial arrangement in randomized complete block design with three replications. Experiment was carried out in a factorial arrangement based on randomized complete block design with three replications. Treatments included seed priming (hydropriming and control) and plant growth regulators application (nine cytokinin and auxin application levels at one and two weeks after anthesis). The results showed that hydropriming significantly increased grain yield by about 8% in comparison with control (7030 and 6507 kg.ha, respectively). Application of cytokinin and auxin hormones had positive effect on photosynthesis and soluble proteins of flag leaf. In addition, number of endosperm cells was also increased by application of growth regulators. The highest effect on increasing source strength was observed in application of cytokinin in both times of foliar application. Grain filling rate was also significantly highest, about 1.79 mg grain day, in cytokinin-cytokinin foliar application, followed by auxincytokinin. Grain yield in cytokinin-cytokinin (7891 kg.ha) increased by 24.7% in comparison with control. Interaction effect of seed priming × plant growth regulator application was not significant for any traits. Results of this experiment showed that seed priming increased number of spike per.m. Foliar application of auxin and cytokinin also may increase grain yield of wheat through enhancing of source and sink strength.