Effects of different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower under water stress

The role of arbuscular mycorrhizal fungi in alleviating water stress is well documented. In order to study the effects of water stress and two different mycorrhiza species on grain yield, nutrient uptake and oil content of sunflower, a field experiment as split plot design with three replications was conducted in the Research Field Station, Zabol University, Zabol, Iran in 2011. Water stress treatments included control as 90% of field capacity (W1), 70% field capacity (W2) and 50% field capacity (W3) assigned to the main plots and two different mycorrhiza species, consisting of M1 = control (without any inoculation), M2 = Glumus mossea and M3 = Glumus etanicatum as sub plots. Results showed that by increasing water stress from control (W1) to W3 treatment, grain yield was significantly decreased. The reduction in the level of W3 was 15.05%. The content of potassium in seeds significantly decreased due to water stress but water stress upto W2 treatment increased the content of phosphorus, nitrogen and oil content of seeds. In between two species of mycorrhiza in sunflower plants, Glumus etanicatum had the highest effect on grain yield and these elements in seeds and increased both.