Effects of Pistachio Rootstocks on Ecophysiological Characteristics of Commercial Pistachio Cultivars

Ecophysiological characteristics of "Ahmadaghaii" "Ohadi" "Kallehghuchi" cultivars (as scions) on four pistachio rootstocks (Pistacia vera Cv. Badami riz, P. vera Cv. Sarakhs, P. atlantica sub sp. Mutica, P. atlantica sub sp. Atlantica) were evaluated during the spring and summer seasons of 2005 in the Iran's Pistachio Research Institute (IPRI). Ecophysiological characteristics such as photosynthesis rate (Pn) in leaf surface (μmol ms), stomatal conductance (gs), transpiration rate (E), leaf internal CO2 concentration (Ci) and leaf temperature (C) were measured in the 6 stages of nut growth and development. Results indicated that rate of photosynthesis, stomatal conductance and transpiration increased until second stage of nut growth and development and then decreased until harvesting stage. Negative correlation was found between photosynthesis and leaves internal CO2 pressure. The highest rate of photosynthesis (16.59 μmol ms), stomatal conductance (0.456 mol m s) and transpiration rate (6.357 mmol ms), were found in Sarakhs rootstock and the lowest (P < 0.01) was measured in Mutica. In addition, three indexes (Pn, gs, E) decreased within Sarakhs, Atlantica, Badami riz and Mutica rootstocks, respectively.