Title: EFFECT OF MYCORRHIZAL INOCULATION AND METHANOL SPRAYING ON SOME PHOTOSYNTHETIC CHARACTERISTICS AND YIELD IN WHEAT CULTIVARS UNDER END-SEASON DROUGHT STRESS
Abstract: A two-year study was carried out with split-plot factorial arrangement based on randomized complete block design in three replications in Khorramabad, Iran, during 2012-2014.The studied factors in the main-plots included end season drought stress at three levels (normal irrigation, mild stress and severe stress with irrigation based on 40%, 60% and 80% moisture depletion of soil water available to plants) and mycorrhizal biofertilizer factors and methanol spraying at four levels (without mycorrhiza inoculation + distilled water spraying, control; mycorrhiza inoculation + distilled water spraying; without mycorrhiza inoculation + methanol spraying; and mycorrhiza inoculation + methanol spraying).Moreover, the three irrigated wheat cultivars Aflak, Dena and Alvand with factorial arrangement were in sub-plots.Results demonstrated that drought stress decreased stomatal conductance, leaf transpiration, photosynthesis rate and grain yield.Crop plants under mild stress conditions experienced lower carbon dioxide in sub-stomatal chamber, whereas, its accumulation in those plants that were under severe stress conditions increased significantly.The studied cultivars responded to drought stress differently.Yield reduction in Alvand was more severe than in Aflak and Dena under mild and severe drought stress conditions.The results suggested that mycorrhizal inoculation and methanol spraying play an important role in enhancing drought tolerance in susceptible wheat cultivars to drought stress.Moreover, they can be used in irrigated wheat farming to reduce damages caused by end season drought stress.