EFFECTS OF SOME PISTACHIO ROOTSTOCKS ON LEAF PHOTOSYNTHESIS RATE OF THREE IRANIAN COMMERCIAL PISTACHIO CULTIVARS

In this research, photosynthesis activity of three Iranian commercial pistachio cultivars was evaluated during the spring and summer of 2005 in the 6 stages of nut growth and development in the Iran’s Pistachio Research Institute (IPRI). Selected rootstocks included Pistacia vera cv. Badami riz, P. vera var. sarakhs, P. atlantica subsp. mutica, P. atlantica subsp. atlantica and the cultivars were ‘Ohadi’ ‘Kalle-Ghoochi’ and ‘Ahmad-Aghai’. Photosynthesis rate (Pn, µmol m^-2 s^-1) was measured with an LCA-4 apparatus. The highest photosynthetic rates coincided with the end of endocarp growing and at the beginning of endocarp lignification. The lowest photosynthetic rate was observed at the harvest time. Within rootstocks, trees on sarakhs and atlantica showed the highest photosynthetic rates while trees on rootstocks of cv. Badami riz and mutica had the lowest rate of photosynthesis.