Effect of Trichoderma harzianum fungus on the physiology traits and some ‎vegetative and reproductive characteristics of tuberose (Polianthes tuberose L. cv. ‎Double) under drought stress conditions‎

In order to investigate the effect of different levels of Trichoderma fungus on some morpho-physiological and flowering traits of tuberoseunder drought stress conditions, an experiment was conducted in a factorial based on completely randomized design with three replications in greenhouses of Ferdowsi University in 2017. The first factor was drought stress at three levels (100 (Control), 50 and 25% FC) and the second factor was Trichodermaharzianum biat three levels (20, 10 and 0% pot weight). The results showed that drought stress increased the amount of antioxidant and proline and had a negative significant effect on fresh and dry weights of root and bulblet, Relative water content, leaf number, floret diameter and number of open florets, but Trichoderma largely moderated these negative effects. The highest amount of relative humidity content of leaf water (84.5%) was obtained at 10% level of fungus, which did not show a significant difference from 20% level of fungus. In the rest of the traits, the highest levels were found at 20% level of fungus. The interactions effect of fungus and droght stress on the floret diameter, fresh and dry weights of root and bulblet were significant and Trichoderma fungus improve the negative effects of drought stress. Trichoderma fungus, besides reducing the effects of drought stress, increases vegetative growth and bulblets and increases the number of open florets. Based on results, use of Trichoderma fungus can be suggested as a effective factor in increasing the quality of tuberoseflower in similar conditions.