Effects of Water Deficit Stress and Two Mycorrhiza Species on Some Physiological Attributes and Tuber Fresh Weight of Potato cv. Agria Under Field Condition

In order to evaluate the tuber fresh weight and some physiological attributes of Agria potato cultivar in response to water deficit stress and mycorrhiza inoculation, a field trial was conducted as a split plot scheme based on randomized complete block design with three replications at the research site of Islamic Azad University, Tabriz Branch in 2012. Four water levels including: irrigation after 60 (S0) mm evaporation from class A pan as the control and irrigation after 90 (S1), 120 (S2) and 150 (S3) mm evaporation from the pan as water deficit stress conditions were arranged in the main plots and four levels of arbuscular mycorrhizal fungi (AMF) including: no AMF (M0), inoculation of Glomus etunicatum (Ge) (Becker and Gerdemann), Glomus intraradices (Gi) (Schenck and Smith) and dual inoculation of the two species (Gei) were arranged in the sub-plots. Water application and AMF inoculation had significant effect on all of studied attributes. Increasing of water deficit stress intensity increased stomatal resistance and decreased leaf relative water content and tuber fresh weight. On other hand, positive effect of AMF inoculation was observed on stomatal resistance, leaf relative water content, leaf chlorophyll content and tuber fresh weight. Also, significant interaction between water application and AMF inoculation was observed for stomatal resistance, leaf relative water content, leaf chlorophyll content and tuber fresh weight. In general, water deficit stress decreased tuber fresh weight in non-mycorrhizal and mycorrhizal potatoes. In all of water levels, maximum tuber fresh weight was observed by inoculation with G. intraradices.