Evaluation of Salinity Tolerance in some Interspecific Hybrids of Prunus

In this research, an almond (Prunus amygdalus B.) cultivar (Sahand) and four interspecific hybrid rootstocks (HS314, HS312, HS302 and GF677) of Prunus genus were subjected to the salinity levels of 1.5, 3, 6 and 9 dS m-1. The mixtures of NaCl, Na2SO4, MgSO4 and CaCl2, at ratios of 12/8, 11/1, 10/2 and 20/7 (w/v) were used respectively to prepare saline solutions. Based on the results obtained, salinity had a significant negative effect on leaf chlorophyll content, leaf area and dry and fresh weight of root and shoot. Although leaf proline concentration was increased by increasing salinity levels, but different responses were observed among the genotypes in this respect. Most of plant responses were significant in high concentrations of salinity (6 and 9 dS m-1) and there were no deleterious effects on the plants growth in 1.5 and 3 dS m-1 salinity. The variation of leaf proline was significant in all levels of salinity but increasing of proline in Sahand cultivar was lower than other genotypes and HS302, indicated the highest amount of proline in higher salt stress. Total chlorophyll and chlorophyll b were decreased significantly by increasing salinity level, but there was no significant change in chlorophyll a. Salinity led to the significant differences among genotypes related to K+, Mg2+, Ca2+, Na+ and Cl- concentrations of leaves and roots. Concentration of Mg2+, Cl- and Na+ and Na+/K+ ratio in leaves of all genotypes were enhanced by salinity stress, whereas it had not significant effect on Ca2+, K+ concentrations and Na+/ Ca2+ ratio. According to measured parameters, HS314 and GF677 were relatively salinity tolerant than others genotypes.