1Department of Plant Genetics and Production Engineering, University of Mohaghegh Ardabili, Ardabil, Iran
2Department of Animal Science, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran
3Department of Animal Science Research, Ardabil Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Ardabil, Iran
4Department of Agronomy and Plant Breeding, Agriculture Institute, Research Institute of Zabol, Zabol, Iran
چکیده
Pistacia vera L. is a perennial tree species of significant economic importance, exhibiting natural adaptation to arid and semi-arid environments. Elucidating the genomic underpinnings of this adaptation is crucial for enhancing stress resilience and facilitating breeding programs. This study employed whole-genome sequencing data from 31 Iranian pistachio samples to characterize runs of homozygosity (ROHs) and identify genomic regions potentially shaped by selective pressures. A total of 3597 ROHs were detected, predominantly comprising short segments (<200 kb), which reflect both the scaffold-level genome assembly and historical recombination patterns. The overall genomic inbreeding coefficient (FROH) was low (mean = 0.026), suggesting limited recent inbreeding within the studied accessions. Utilizing SNP frequency-based criteria, 48 ROH islands were identified across 44 scaffolds, representing localized regions of elevated homozygosity. Functional annotation of these regions revealed 589 protein-coding genes, many of which are associated with stress responses, hormonal regulation, metabolism, and development. Notably, genes such as HDAC9, implicated in epigenetic regulation under heat stress; NCED6 and PSY2, key components of abscisic acid and carotenoid biosynthesis pathways, respectively; AAE3, linked to oxalate metabolism and tolerance to biotic and abiotic stresses; TPR1, associated with drought response; and ATG5, a central regulator of autophagy under diverse stress conditions, were localized within ROH islands. Collectively, these findings indicate that ROH-based analyses can effectively delineate genomic regions and candidate genes potentially involved in environmental adaptation and trait optimization in pistachio. This study provides a genomic framework for comprehending selective processes in P. vera and offers valuable targets for future functional investigations and molecular breeding initiatives.