Kelussia odoratissima Mozaff. belonging to the Apiaceae family, is well known for its medicinal and nutritional importance, endemic to Iran. Seed dormancy is a major problem present in Kelussia odoratissima leading to low germination percentage; thus, improvement of seed germination and breaking seed dormancy is important. Piriformospora indica, a root-colonizing endophytic fungus, promotes plant growth, development and resistance to biotic and abiotic stresses. In order to evaluate the effects of different treatments of P. indica on seed germination traits of Kelussia odoratissima, an experiment was conducted based on completely randomized design with five treatments and three replications. The experimental treatments were application of fungal mycelium of P. indica (M), spore suspension of P. indica (S), the combination of Gibberellic acid and fungal mycelium (H+M), the combination of Gibberellic acid and spore suspension (H+S), and control (C). Based on the results the highest percentage of germination (75%) and the highest germination rate was related to spore suspension of P. indica. The lowest amount of germination uniformity (GU) observed in spore suspension of P. indica treatment. Among the different treatments, application of P. indica spore suspension resulted in lowest times for 10% germination (D10) and 90% germination (D90). The highest plumule and radicle length observed in spore treatment and in comparison with control, application of spore suspension of P. indica increasedplumule and radicle length by 16% and 32%, respectively. Based on the current results, it seems that spore suspension of P. indica was the best treatment for improvement of seed germination traits.
