Effect of arbuscular mycorrhizal fungi on root colonization and phosphorus uptake of linseed (Linum ussitatissimum L.) under drought stress conditions

One of the most important limiting factors of crop growth in the arid and semi-arid regions is water deficit. Mycorrhizal fungi is one of the most important microorganisms in the rhizosphere. The effects of these fungi apply via changes on some of the characteristics of roots and nutrients uptake in host plants under drought conditions. In order to evaluate the effect of arbuscular mycorrhizal fungi under drought stress on linseed, a field experiment was conducted as split-plot arrangement in RCBD with three replications at the Research Station of Faculty of Agriculture in Shahrekord University in 2013. Drought stress at four levels of no stress, mild, medium and severe stress as the main factor and inoculation with Glomus intraradices, Glomus mosseae and no inoculation as sub factor were evaluated. The results showed that the effect of mycorrhiza inoculation and drought stress treatment had significant effect on all measured traits. The interaction between mycorrhiza and drought stress treatments was significant in all measured traits except, aboveground fresh weight, root fresh weight, root length, root/shoot ratio and uptake of phosphorus. Drought stress decreased all measured traits, but increased root dry weight/shoot dry weight ratio. The results showed that the maximum (32.82%) and minimum (8.68%) root colonization rate were obtained in no drought stress inoculated with G. intraradices and under hard stress no inoculation of mycorrhiza respectively. Based on resulted in this experiment symbiosis of linseed with of arbuscular mycorrhizal fungi caused increased in all traits. Keywords: Drought, Inoculation, Nutrient uptake, Symbiosis of mycorrhizal fungi