Effect of arbuscular mycorrhizal fungi on some agronomic characteristics on linseed (Linum ussitatissimum L.) under drought stress

Background and objectives: One of the most important limiting factors of crop growth in the arid and semi-arid regions, is water deficit stress. Mycorrhizal fungi are 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 nutrient uptake in host plants in drought conditions. However, symbiotic mycorrhizal fungi with Linseed plant have not been studied yet. Thus, this experiment was conducted in order to investigate the effect of arbuscular mycorrhizal fungi under drought stress condition on some qualitative traits and nutrient uptake of linseed.
Materials and methods: This experiment was conducted in the research station of Faculty of Agriculture in Shahrekord University, with latitude of 32 degree and 20 minute north and longitude of 50 degree and 51 minute east, and altitude of 2061 meters above sea level and about 319.5 mm annual rainfall, in 2013. The experiment was conducted as split-plot design in RCBD with three replications. Drought stress at four levels of 100 % (no stress), 75 % (mild), 50 % (medium) and 25 % (sever stress) of water requirement, as main factor and inoculation with Glomus intraradices, Glomus mosseae and no inoculation as sub factor were treated. The measured traits were percent of seed oil, seed oil yield, proline content in leaves, and concentration and uptake of phosphorus, potassium, calcium in shoot and concentration and uptake of sulfur in seed.
Results: The results showed that the effects of drought stress treatment were significant on all measured traits except uptake of potassium and calcium. Drought stress decreased oil content (%) and oil production, concentration and uptake of phosphorus and sulfur, but increased proline content, concentration of potassium and calcium. Mycorrhiza increased all measured traits. The interaction between mycorrhiza and drought stress treatments was significant in all measured traits except proline content, concentration and uptake of sulfur. Regression analysis showed significant relation on the linseed traits of oil content, oil yield, P content, P absorption, K content and Ca content and these relations were linear or polynomial order 2.
Conclusion: Based on resulted in this experiment symbiosis of linseed with of arbuscular mycorrhizal fungi under drought stress caused increased in all traits. The use of both species of fungi showed more effective than the non-application on the measurement traits. The effect of both types of fungi Glomus intraradices and Glomus mosseae was almost identical.