The effect of mycorrhiza fungi on the morphological characteristics, phenolic compounds. and chlorophyll fluorescence of Borage (Borago officinails L.) under draught stress

Drought is one of the factors that affect medicinal plants. On the other hand, the role of mycorrhiza fungi was effective in improving the performance of some medicinal plants exposed to draught stress. For this purpose, an experiment was conducted as split-plot in a randomized complete block design with 3 replications in the Boyerahmad region during 2015 - 2016. The experiment factors consisted of irrigation levels (main plot) as irrigation after S1 =30, S2 =60, S3 =90, S4 =120 and S5 =150 mm water evaporation from evaporation pan class A and mycorrhiza fungi (sub plot) consisted of non-inoculation (NG), inoculation with mycorrhiza fungi species of Glomus mosseae (GM) and Glomus intraradices (GI). Results showed that the effect of year on the studied traits of Borage was not significant. The effect of drought stress on leaf area index of Borage was significant and in the irrigation after 30 and 60 mm evaporation the highest LAI was obtained. The application of mycorrhiza fungi Glomus mosseae and Glomus intraradices increased the amount of phenols of Borageby %13 and% 9, respectively as compared with the plants not inoculated with mycorrhiza fungi. Increase in the drought from 30 mm to 150 mm decreased evaporation, height, number of tributaries and chlorophyll fluorescence, but the application of mycorrhiza could increase the studied characteristics of Borage under drought stress conditions and decrease the negative effects of stress.