Evaluation of root colonization and biochemical compounds of saffron under irrigation regime, arbuscular mycorrhizal fungi and organic fertilizer

In order to evaluate the potential of native species of saffron arbuscular mycorrhizal fungus under the conditions of irrigation cut stress on its physiological traits, a study was conducted as split plot factorial based on a randomized completely design with three replications in the institute of Soil and Water research in Karaj, during the years 2017-2019. Treatment consisted: Irrigation regime as the main factor in three levels (such as optimal irrigation as control, water interruption at the beginning of the growing season (mild restriction water) and water interruption at the beginning and mid of the growing season (severe restriction water)), organic fertilizer in three levels (no organic fertilizer, vermicompost (20 ton ha-1) and biochar (10 ton ha-1) and Arbuscular mycorrhizal fungal in three levels (no application, isolate a and isolate b) as the subfactor. . Based on the molecular findings, both isolate isolated from saffron rhizosphere belonged to Rhizophagus irregularis. The results of this study showed that the interaction of irrigation regime, organic fertilizer and R. irregularis had a significant effect on all measured parameters. The highest percentage of root colonization (98.7%) was for optimal irrigation treatment with biochar and isolate b. The highest content of chlorophyll a, b and carotenoids (with an average of 5.74, 4.36 and 1.52 μg / ml, respectively) was observed in the optimal irrigation treatment with vermicompost and isolate b. Also, the treatment of severe water restriction with biochar and isolate b increased 253, 82, 95 and 165% of CAT, POD and SOD enzyme activities and proline, respectively, in comparison with the optimal irrigation treatment and no application of organic fertilizer and mycorrhiza fungal, which had the lowest amount of these traits. According to the results obtained from this study, it is argued that the use of biochar and vermicompost fertilizers with isolate b can reduce the destructive effects of soil moisture stress.