Mycorrhizal treatments increase the compatibility between Pistachio (Pistacia vera L.) cultivars and seedling rootstock of Pistacia terebinthus L.

• We analyzed the potential of P. terebinthus as rootstock for P. vera buds in Spain.
• Treatment with mycorrhizae increases the efficiency of nutrient uptake.
• Treatment with mycorrhizae increases the efficiency of grafting to 40%.
• Treatment with phytohormones has no effect on either grafting or nutrient uptake.
• Tandem mycorrhized P. terebinthus rootstock–P. vera bud is highly recommended in Spain.

The bud–rootstock compatibility is decisive in the success of grafting pistachios. Climate conditions and appropriate rootstock choice are the two key factors influencing grafting success. Despite producers’ efforts, fluctuations in these factors result in frequent differences in annual yield. To minimize production losses by increasing the percentage of successful grafting would greatly benefit the introduction of this crop in new areas.Here, we analyze the viability of Pistacia terebinthus L. differentially treated with mycorrhizae or phytohormones and used as rootstock for Pistacia vera buds. Our results, on an experimental plot of 12,905 plants, demonstrate that mycorrhiza-treated plants reached ∼80% positive grafts, while the phytohormone-treated plants and controls had 32.3% and 38.4% success, respectively. The increase in grafting success could be explained by more efficient nutrient uptake in mycorrhiza-treated plants. An analysis of chemical element accumulation and assimilation in leaves reveals that mycorrhiza-treated plants selectively accumulated Ca, Fe, Mg, N, Al, S, Sr, Ti, V, Mn, and Tl, but lacked K with respect to the rest of the plants. Mycorrhiza-treated plants were shorter, but no significant differences were found in trunk diameter and circumference. We propose the use of mycorrhizae to increase bud–rootstock compatibility for this tandem of species.