Investigating the Genetic Diversity of Male Trees in a Wild Sarakhs Pistachio Population and Identifying Promising Pollinizer Genotypes

Plant Germplasm is the main source used by the plant breeders and the most important national treasures of any country. Iran has one of the largest and most unique wild species of pistachio (Pistacia vera L., var. Sarakhs) forests in the world, which is a valuable genetic resource. The main objective of the present study was to investigate the genetic diversity of male genotypes in this collection and determine the genetic distance and their grouping. Detecting characteristics of each group of these genotypes, which can be indicated the genetic value for productivity in breeding programs was another perspective of the project. The present study was carried out in a randomized complete block design (RCBD) with 5 replications for 3 years (2017-2019) at Station 2 of Pistachio Research Center. The results of evaluation genetic variation with morpho-physiological indices and phonological stages of flowering showed that 188 males of these populations are classified in 33 different genotypic groups. The results of analysis of variance (ANOVA) showed that there was a significant difference between selected genotypes in all measured traits. Flowering period of male genotypes in this population was 35.2 days, indicating significant variation at flowering time among male genotypes. Compatibility assessments showed that among 33 male genotypes, M5 in addition to its ability to produce suitable pollen grains had a good overlap with flowering time of commercial cultivars including Ahmad Aghaei, Kaleh-Ghoochi and Owhadi. Genotypes M12, M13, M14, F4M and M106 were selected as the ideal pollinizers for Akbari cultivar among the genotypes overlapping with this commercial cultivar. Grouping genotypes based on square Euclidean distance showed that male populations were classified into 2 main and 5 subgroups, confirming the existence of widespread genetic diversity in wild "Sarakhs" pistachio. The finding demonstrated that this collection, as a valuable germplasm, has a high diversity and breeding potential that can be used in pistachio breeding programs.