**5. Use of SSR markers in the genus** *Pistacia*

There are only several studies characterizing *Pistacia* species and *P. vera* accessions using SSR markers. Pazouki et al. [38] used SSR markers and characterized 304 *Pistacia* accessions belonging to *P. khinjuk*, *P. vera,* and *P. atlantica* subsp. *kurdica*. The authors indicated lower level of polymorphism and variation within *P. atlantica* subsp. *kurdica* than *P. vera* and *P. khinjuk*. Motalebipour et al. [14] used 1505 alleles amplified by 136 SSR primer pairs for phylogenetic analysis of 6 *Pistacia* species. The closest species to *P. vera* was *P. atlantica*, and *P. integerrima*, *P. chinensis*, *P. terebinthus* followed it, while *P. lentiscus* was the most diverse species to the cultivated pistachio. The structure analysis confirmed the cluster analysis as well. Albaladejo et al. [30] used 8 SSR loci to characterize 42 *P. lentiscus* accessions belonging to 2 *P. lentiscus* populations. The number of alleles changed between 3 and 13 by obtaining a total of 59 alleles. The expected heterozygosity ranged from 0.139 to 0.895. Two *P. lentiscus* populations were separated clearly in cluster analysis. Chen et al. [32] characterized 24 *P. weinmannifolia* accessions using 14 SSR loci. The number of allele changed between one and nine with an average of 4.1. *Ho* values were between 0.000 and 0.933, while *He* values ranged from 0.000 to 0.906.

Ahmad et al. [37] used 14 SSR loci to characterize Iranian, Turkish, and Syrian pistachio cultivars. A total of 46 alleles was produced by 14 SSR loci ranging from 2 to 5 allele per loci. Cluster analysis placed most of the Iranian samples in one group, while the Syria samples were the most diverse and did not group in a single cluster. Kolahi-Zonoozi et al. [27] described 45 Iranian pistachio accessions by 12 SSR loci. The *PIC* values changed between 0.19 and 0.56 with an average of 0.33. The average *Ho* and *He* values were 0.490 and 0.345, respectively. Khodaeiaminjan et al. [28] characterized 18 pistachio cultivars from different origins by 2631 SSR alleles using 625 SSR loci. The constructed dendrogram separated pistachio cultivars mainly in two groups according to their geographical origin: one group contained the cultivars originated from Iran, and the second group included cultivars originated from Mediterranean countries such as Turkey, Syria, Greece, and Italy. Siirt cultivar (origin is Southeast part of Turkey) placed between two main groups. The results were in agreement with a hypothesis on diffusion of pistachio cultivars suggested by Kafkas et al. [19] who hypothesized that the Siirt cultivar is in a transition subcluster between Iranian and Mediterranean cultivars and pistachio cultivation diffused from its center of origin, the Iranian-Caspian region, via southeastern Turkey to Syria, the Mediterranean region of Europe, and North Africa. Motalebipour et al. [14] used 1505 alleles from 136 SSR primer pairs for genetic diversity analysis of 24 pistachio cultivars, and similar results were obtained with the study performed by Khodaeiaminjan et al. [28].

The SSR markers in the genus *Pistacia* were also used for genetic linkage map construction and QTL analysis. Khodaeiaminjan et al. [28] constructed the first SSR-based genetic linkage map of pistachio using an F1 segregating population derived from a cross between "Siirt" and "Bağyolu" cultivars. A total of 385 SSR markers was mapped along with 15 chromosomes, and the consensus map had 1511.3 cM length with an average of 25.6 SSR markers per LG, and the average distance between the markers was 3.9 cM with a 0.25 marker density. The first QTL study in pistachio was performed by Motalebipour et al. [35] who constructed a genetic linkage map of pistachio using an inter-specific F1 population and SSR markers. The authors mapped a total of 388 SSR markers along with 15 linkage

groups. The length of consensus map was 1492 cM with an average marker distance of 3.7 cM. The QTL analysis was performed for 5 morphological traits such as leaf length, leaf width, number of leaflets, young shoot color, and leaf color, and 17 stable QTLs during 2 consecutive years were identified. The released SSR-based genetic linkage maps and reported QTLs can be useful genetic resources for future genetic studies in pistachio.
