Effects of different irrigation regimes and two arbuscular mycorrhizal fungi on some physiological characteristics and yield of potato under field conditions

Symbiosis between arbuscular mycorrhizal fungi and host plant roots may improve water and nutrient uptake by host plants. To evaluate this, a field experiment was carried out for 2 years. In both years, the experiment was arranged in a split plot system based on randomized complete block design with three replications. Irrigation regimes, as irrigation after 60 (S-0), 90 (S-1), 120 (S-2) and 150 (S-3) mm evaporation from class A pan were arranged in main plots and two fungal species (Claroidoglomus etunicatum and Rhizophagus intraradices) were included in sub plots. During the growing season, some morpho-physiological traits, tuber yield, and phosphorus and potassium contents of potato were measured. Then, combined analysis of variance was executed using the 2-year data. Leaf proline content (LPC) increased by 38.87, 51.93 and 41.54% and leaf water potential (psi(w)) decreased by 20.95, 31.43 and 59.05% at S-1, S-2 and S-3 compared with S-0 in the first year of experiment, respectively. The corresponding trend for the second year of experiment was 20.11, 25.21 and 26.06% increase for LPC, 7.46, 12.69 and 18.66 decrease for psi(w), respectively(.) The mean of tuber yield loss for 2 years was 20.78, 36.46 and 50.36% at S-1, S-2 and S-3 compared with S-0, respectively. The minimum LPC value was 4.16 (mu mol g(-1) FW) in C. etunicatum treated plants. Inoculation with R. intraradices increased tuber yield by 36.00-32.48% compared with non-inoculated control plants in 2013 and 2014, respectively. The maximum root colonization percentage (RCP) was 54.20% in R. intraradices inoculated plants.