Effect of Putrescine, Vermicompost and Mycorrhiza on Yield, Activity of Antioxidant Enzymes and the Changes of Some Physiological Traits of Triticale in Different Irrigation Regimes

In order to evaluate the effect of putrescine, vermicompost and mycorrhiza on yield, activity of antioxidant enzymes and some physiological traits of triticale in different irrigation regimes, an experiment was conducted as factorial based on randomized complete block design with three replications at the Research Farm of University of Mohaghegh Ardabil, northwest of Iran in 2020. The experimental factors included irrigation in three levels (full irrigation as control; irrigation withholding at 50% of heading, and irrigation withholding at booting stage), application of bio-organic fertilizers in four levels (no application as control, application of vermicompost, mycorrhiza, and simultaneous application of vermicompost and mycorrhiza), foliar application of putrescine in three levels (foliar application with water as control, foliar application of 0.4 and 0.8 mM). The results showed that the irrigation withholding in booting stage with application of mycorrhiza, vermicompost and foliar application of 0.8 mM putrescine increased activity of catalase, peroxidase and polyphenol oxidase enzymes compared with no application of bio-organic fertilizers and putrescine at the same irrigation level. Evaluation of some physiological traits showed that at 242 days after planting, the simultaneous application of vermicompost and mycorrhiza and foliar application of 0.8 mM putrescine under irrigation withholding in booting stage conditions increased the relative water content (39.1%), chlorophyll a content (49.3%), chlorophyll index (37.2%), stomatal conductance (32.1%), variable fluorescence (84.9%), maximum fluorescence (45.1%), and quantum efficiency of photosystem II (27.6%) in comparison with no application of biofertilizers and putrescine at the same irrigation level. Moreover, application of vermicompost and mycorrhiza and foliar application of 0.8 mM putrescine at full irrigation conditions decreased hydrogen peroxide (29.2%), while increased grain yield (39.6%) in comparison with no application of biofertilizers and putrescine under irrigation withholding in booting stage. It seems that the simultaneous application of mycorrhiza and vermicompost and foliar application of putrescine can increase the grain yield of triticale under water limitation conditions due to improvement of antioxidant enzymes activity and some physiological traits.