Effect of Claroideoglomus etunicatum and Indole-3-acetic Acid on Growth and Biochemical Properties of Vetiver Grass (Vetiveria zizanioides) Under Salinity Stress

Salinity represents a major environmental factor limiting plant growth and productivity. In order to better understand the effects of arbuscular mycorrhizal fungus <i>Claroideoglomus etunicatum</i> and Indole-3-acetic acid (IAA) on the growth and chemical composition of vetiver grass (<i>Vetiveria zizanioides</i>) under salt stress, a factorial experiment was conducted in a completely randomized design with three replications. The experiment included four NaCl levels (0, 8, 16, and 24 decisiemens per meter (dS/m)) and four levels of treatments (no amendment application, application of IAA, application of <i>C. etunicatum</i>, and interaction of IAA and <i>C. etunicatum</i>) with three replications. The results of the experiment showed that the addition of sodium chloride increased the concentration of proline and the activities of catalase, peroxidase, and superoxide dismutase enzymes. The application of the growth regulator (IAA) and <i>C. etunicatum</i> significantly increased the fresh and dry weight (101%) of shoots, dry weight of roots, and the concentration of macro- and micro-elements in shoots under salinity condition (99.82% phosphorus; 9.79% Iron). The application of mycorrhiza and auxin significantly reduced the concentration of proline and the activities of catalase, peroxidase, and superoxide dismutase enzymes. In general, the addition of IAA and <i>C. etunicatum</i> to roots under salt stress conditions can improve growth and increase the concentration of some nutrients in vetiver shoots.