Effects of drought stress and arbuscular mycorrhizal fungi on some morphophysiological traits and yield of savory (Satureja hortensis L.)

Water deficit stress permanent or temporary limits the growth and distribution of natural vegetation and performance of plants more than other environmental factors. In order to investigate the effect of drought stress and mycorrhizal-arbuscular fungi inoculation on the growth and yield of savory (Satureja hortensis L.) a factorial experiment based on completely randomized design were conducted in Research Greenhouse of Horticulture Department of Mohaghegh Ardabili University during 2010. Experimental treatments include two species of mycorrhizal-arbuscular fungi, Glomus etunicatum and G. versiformis and three level of drought stress (100 percent of field capacity as control, 30 and 60 percent of field capacity humidity). Result revealed that 8 weeks after start of drought stress treatments growth parameters such as plant height, number and surface area of leaves, root length, of root, stem and leaves dry weight significantly reduced with increase in drought stress severity. Leaf relative water content reduced by drought significantly. Also, result showed that with increase drought stress, phosphorus content of leaves decreased and potassium content of leaves were raised. Proline content of leaves increased in responses to increases in drought stress. Mycorrhizal fungi inoculation significantly (p≤ 0.01) increased vegetative growth indices, relative water content of plants, phosphorus and potassium content of leaf under water deficit condition in comparison to control, but proline content of leaf was decreased. In general, mycorrhizal fungi application improved resistance to drought stress in savory plants.