Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 54 1 2023 03 21 The effect of thiamine and pyridoxine on yield and some physiological wheat traits under drought stress conditions The effect of thiamine and pyridoxine on yield and some physiological wheat traits under drought stress conditions 11 25 92511 10.22059/ijfcs.2022.328186.654884 FA Akbar Seifi Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Tehran, Karaj, Iran 0000-0002-1556-5309 Ali Ahmadi Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Tehran, Karaj, Iran 0000-0003-0044-2645 Kazem Poustini Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Tehran, Karaj, Iran 0000-0002-3740-1129 Journal Article 2021 12 18 Drought stress is one of the most important abiotic stresses limiting wheat production. To improve the growth and yield of wheat under drought stress, a factorial experiment was performed based on a randomized complete block design with three replicates in the research greenhouse of the University of Tehran. Experimental treatments included irrigation at two levels (well-watered and drought stress) and vitamin foliar application at four levels (control, thiamine, pyridoxine, and thiamine+pyridoxine). The results showed that drought stress reduced the relative water content of flag leaves by 21%. The use of vitamins increased the amount of this trait compared to the control treatment. The chlorophyll number (SPAD) of flag leaf increased under drought stress, but the use of vitamins had no significant effect on this trait. Drought stress had an increasing effect on leaf free proline content and foliar application of thiamine and its combination with pyridoxine, respectively, increased this trait by 53% and 32% compared to treatment without foliar application under drought stress conditions. Also, the percentage of electrolyte leakage and malondialdehyde content of flag leaf under drought stress increased by 31% and 103%, respectively. Vitamins reduced the amount of malondialdehyde and had no significant effect on the percentage of electrolyte leakage. Drought stress also reduced wheat grain and biological yields. Foliar application of vitamins showed an additive effect on these traits compared to the control treatment. The highest grain yield per plant was obtained in treatments of pyridoxine (1.1 g) and its combination with thiamine (1.2 g). Drought stress is one of the most important abiotic stresses limiting wheat production. To improve the growth and yield of wheat under drought stress, a factorial experiment was performed based on a randomized complete block design with three replicates in the research greenhouse of the University of Tehran. Experimental treatments included irrigation at two levels (well-watered and drought stress) and vitamin foliar application at four levels (control, thiamine, pyridoxine, and thiamine+pyridoxine). The results showed that drought stress reduced the relative water content of flag leaves by 21%. The use of vitamins increased the amount of this trait compared to the control treatment. The chlorophyll number (SPAD) of flag leaf increased under drought stress, but the use of vitamins had no significant effect on this trait. Drought stress had an increasing effect on leaf free proline content and foliar application of thiamine and its combination with pyridoxine, respectively, increased this trait by 53% and 32% compared to treatment without foliar application under drought stress conditions. Also, the percentage of electrolyte leakage and malondialdehyde content of flag leaf under drought stress increased by 31% and 103%, respectively. Vitamins reduced the amount of malondialdehyde and had no significant effect on the percentage of electrolyte leakage. Drought stress also reduced wheat grain and biological yields. Foliar application of vitamins showed an additive effect on these traits compared to the control treatment. The highest grain yield per plant was obtained in treatments of pyridoxine (1.1 g) and its combination with thiamine (1.2 g). https://ijfcs.ut.ac.ir/article_92511_d8924c1ad5fd09cef29eb79cd8e1d1cf.pdf