Effect of Mycorrhizal Fungi on Morphophysiologicaland Nutritional Factors of Flying Dragon Rootstock under Salt Stress

Citrus is highly sensitive to water and soil salinity. About 13 percent decrease of citrus yield per each 1 dS m -1 increase in salinity above 1.4 dS m-1. Arbuscularmycorrhizal (AM) fungi are probably distributed in most soils and approximately 90% of higher plant species examined interact with AM fungi.AM growth hyphae increased root level, water absorption efficiency and nutrient distribution specially phosphorus and zinc. More biomass and less proline content in citrange "carrizo" inoculated with Glomusintraradices in compare with non-inoculated treatment under different salinity levels. Two symbiosis AM (Glomusmosseae and Paraglomusoccultum) through growth improving, photosynthetic rate and root structure could reduce adverse effects of salinity under 100 mM sodium chloride concentration. We analyzed the impact of two mycorrhizal fungi under salinity stress. Our objectives were to determine how AM symbiosis can alleviate adverse effect of salinity and which of our mycorrhizal fungi show better results. Seed of Flying dragon were sterilized by immersion in 70% alcohol for 4 min, rinsed 5 times with distilled water and germinated in jiffy pots at 27ºC. 25 g of fungi (Glomusmosseae and Paraglomusoccultum) per pot were used while non-AM fungi treatments received the same weight of growth media. The experimental design conducted in a completely randomized design as a factorial form. First factor was four levels of salinity (0, 50, 100 and 150 mMNaCl) and the second factor was two different genotypes of mycorrhizal fungi. Six replicates of each treatment were applied. Control treatments were irrigated with distilled water. Shoot and root dry weight were measured. Concentration of proline was measured by the method of Bates et al (3). AM colonization was estimated in according to with Hashem et al (14) with using light microscopy. Relative water content (RWC) was measured by Wu and Xia (28). The sucrose and glucose were determined by Wu et al (29) method. Na+, K+ and Ca+ concentrations in leaves were measured by using atomic absorption spectrometer. The data were analyzed by two factor ANOVA using JMP 7 software. Least significant difference (LSD, α