Genetic evaluation of some wild and commercial pistachio species based on morphological characteristics and RAPD-PCR molecular markers

In this study, 44 accessions and cultivars of three species of Pistacia including P. atlantica (15 accessions), P. khinjuk (23 accessions), and P. vera (6 cultivars) collected from different parts of Ilam and Semnan provinces, Iran, were evaluated for leaf and fruit traits. Investigation of morphometric traits revealed that there was a high variability (CVph) in fruit traits compared to leaf traits among species. The results of the principle component analysis (PCA) revealed that the three main components explained 94.04% of the total variation among the accessions. In PCA1, the fruit weight, length, and diameter, kernel and shell weight were predominant in the first component and explained 52% of the total variation. According to the results of cluster analysis, the accessions were divided into three main groups so that, those belonging to each species were placed into separate groups. Also, in the second part of the experiment, genetic diversity among samples was investigated using 12 RAPD primers. A total of 71 alleles were identified and their sizes ranged from 280 to 2500 bp. The number of observed alleles for each locus ranged from 4 (OPA-18 and OPA-16) to 9 (Custom primer) alleles, with an average of 5.91 alleles per locus. The polymorphic index content (PIC) was the highest (0.81) for the OPB-14 locus and the lowest (0.089) for the OPA-13 locus, and was 0.35 among all RAPD loci. The Jaccard’s genetic similarity coefficient ranged from 0.27 to 0.84 among the samples. The obtained results of the current study will help in the classification, preservation, and identification of Pistachio genetic resources and can be effective in breeding improved varieties of this crop.