Pistachio (Pistacia vera L.) cultivation under rainfed conditions of the South Mediterranean has not been studied in depth. Under changing climate conditions, knowledge of cultivar and rootstock performances allows for the optimal use of genetic resources to improve yield and nut quality. This study aimed to evaluate growth, yield, and fruit characteristics of ‘Mateur’ and ‘Achouri’ pistachio cultivars grafted on P. vera and P. atlantica rootstocks grown in northeastern Tunisia. The research was based on three years worth of monitoring of growth, yield and fruit quality. Results showed that annual bio-climatic features had significant effects on all studied parameters. The ‘Mateur’ cultivar showed higher vigor and fruit yield than ‘Achouri’. Fruit production was higher in P. atlantica rootstock for ‘Mateur’ but similar in both studied rootstocks for ‘Achouri’. Kernel fat contents (40.7–46.8%) and fatty acid profiles were low or not affected by cultivar, rootstock and their combination. Oleic acid (C18:1) was the major fatty acid (68.94–69.22%) in kernel oil. The unsaturated/saturated fatty acid and oleic/linoleic acid ratios indicated that nuts obtained had high quality. The lower performances of ‘Achouri’ cultivar in the studied conditions may be related to low acclimation ability of this cultivar. These conditions, however, seem to be suitable for both studied rootstocks.

The low diversification of rootstocks can be a problem in reducing the adaptation of pistachio to the Tunisian climatic and soil conditions. Nowadays, the most used rootstock is Pistacia vera; however, the autochthonous Pistacia atlantica could be a good alternative. The aim of this work was to study the effect of two different rootstocks Pistacia vera and Pistacia atlantica on the quality and functionality of two pistachio cultivars (the local variety “Mateur” and the Syrian one “Achoury”). The different parameters studied were: morphological (size, weight), chemical (minerals and fatty acids) and functional (total phenolic content, and antioxidant activity: ABTS+, DPPH•, and FRAP). The pistachios are a good source of minerals (especially Ca and K 19.9 and 9.8 g kg-1, respectively, and Fe 54.5 mg kg-1), polyunsaturated fatty acids (oleic and linoleic acids), and phenolic compounds (16.0 g GAE kg-1). The combination P. atlantica and variety “Mateur” led to proper values of tree yield, nut dehiscence, morphology (length and width), and oleic acid content. Thus, it can be concluded that the use of the local rootstock P. atlantica led to promising results and can be a good option due to its higher adaptation to the local climatic and soil conditions.