Changes in Growth Indices of the Almond ‘Shahroud 12’ Grafted on some Prunus Rootstocks under Salt Stress

Almond has a high sensitivity to salt stress. Selection of a tolerant rootstock/scion is one of the ways to reduce the negative effects of salinity stress. In this experiment, the effects of salinity stress on some morphological, physiological and nutritional traits of some almond rootstocks was investigated in a factorial experiment based on completely randomized design with two factors (8 levels of rootstock/scion compositions and five levels of salinity) in three replications at Horticultural Research Institute in 2017. The results showed that by increasing salinity from zero to 8 ds/m, the highest and lowest amount of reduction in root dry weight was observed in ‘Shahrood 12’/Tetra (37.8%) and GN15 (14.5%), respectively. The lowest and highest dry weight loss in the main branch was observed in the bitter almond seedling (38.2%) and ‘Shahrood 12’/ GN15 (47.9%), respectively. The highest amount of necrosis was observed in bitter almond seedling (28.98%) and the lowest value was in ‘Shahrood 12’/GF677 (9.9%). The lowest and highest changes in electrolyte leakage occurred at the rootstock of GF677 (30.74%) and GN15 (42.93%). The lowest and the highest changes in sodium were observed in the ‘Shahrood 12’/GF677 (51.2%) and in the bitter almond seedling (82%), respectively. The results also showed that by increasing salinity stress, the amount of root and leaf nutrient elements increased initially and then decreased with increasing salinity levels. Based on the results, ‘Shahrood 12’/GF677 is the most tolerable combination and the ‘Shahrood12’ grafted on bitter almond seedling is the most sensitive to salt stress.