Cold hardiness evaluation of some Pistacia species based on electrolyte leakage and eco-physiological parameters

Freezing damage is a major limiting factor to Pistachio cultivation in cold climates. Assessment of pistachio genotypes to freezing stress is important for the selection of tolerance cultivars in these regions. In this study, nine genotypes belong to six Pistacia species (P. terebinthus L., P. atlantica Desf., P. atlantica subsp. kurdica P. atlantica subsp. mutica, P. khinjuk Stocks., P. vera var. Sarakhs, P. vera cv. Badami-Riz-Zarand I, P. vera cv. Badami-Riz-Zarand II) and an interspecies hybrid named UCB1 (P. atlantica × P. integrrima) were evaluated to freezing stress at temperatures of -4, -8, -12 and, -16°C in the months of December, January and February. Results showed that electrolyte leakage (EL) percentage and means of eco-physiological parameters varied among genotypes with the highest soluble carbohydrates and phenolic compounds observed in species of P. atlantica subsp. kurdica and P. vera var. Sarakhs respectively. In February, the highest calcium and potassium concentrations of shoot were observed in P. terebinths and P. vera var. Sarakhs genotypes respectively. The highest EL percentage was observed at -16°C in P. atlantica and P. khinjuk and the lowest in P. terebinthus and P. vera var. Sarakhs