Effect of Trichoderma harzianum on seed emergence and seedling growth of barley under copper stress

In order to evaluate the effects of bio-priming by Trichoderma harzianum on copper tolerance of barley seedlings, a factorial experiment was conducted based on randomized complete block design, with three replications in Research Farm of faculty of Agriculture and Natural Resources in University of Mohaghegh Ardabili in year 2016. Experimental factors included pre-treatment (non-priming, hydro-priming, bio-priming, exogenous application of Trichoderma) and copper stress (0.29, 2.9, 29, 290 µM). In the main experiment after seed pre-treatments, barley seeds were sown in plastic pots. After seed planting, the different copper concentrations (as CuCl2) were applied along with hoagland-arnon nutrient solution. The results indicated that the length and dry weight of plants and the length of leaves were significantly decreased when the concentration of copper was increased. So that, plant dry weight was significantly reduced at 29 and 290 μM concentrations of copper and plant and leaf length were further declined at 290 µM. On the other hand, external use of Trichoderma alleviated the deterrent impacts of copper toxicity on plant and leaf length. Bio-priming and hydro-priming of seeds significantly increased emergence percentage and rate. The seedlings obtained from barley seeds, which were primed with Trichoderma, were heavier than seedlings produced from untreated (control) seeds.