Assessment of Genetic Variation in Natural Populations of Hippophae rhamnoides L. from Kazakhstan Using Retrotransposon-Based Markers

Analysis of the genetic diversity of natural populations of economically valuable plants is important for conservation and selection strategies. In this study, the genetic diversity of 11 natural populations of Hippophae rhamnoides L.—sea buckthorn from different regions of Kazakhstan—was studied using Inter-Primer Binding Site Polymorphism (iPBS) markers based on conserved sequences of tRNA primer-binding sites (PBSs) that initiate retrotransposon replication. Universal PBS primers yielded reproducible and informative amplicons, forming unique profiles for each sample. Analysis of molecular variance showed that 60% of the total genetic variation was due to intrapopulation differences and 40% was due to interpopulation differentiation. The highest genetic diversity was found in the Shetlasty and Tersayryk sea buckthorn populations, whereas the Karatal and Topkain populations were characterised by minimal values, although unique alleles were observed in the latter population, indicating possible adaptation to local environmental conditions or genetic isolation. Principal coordinate analysis, UPGMA clustering, and Bayesian structure analysis (K = 4) confirmed geographical structuring. This study provides insights into the genetic structure of sea buckthorn populations in Kazakhstan and demonstrates the effectiveness of iPBS markers for assessing intraspecific diversity. The obtained results provide a basis for the conversation of H. rhamnoides gene pool and underscore the need for both in situ conservation of genetically rich populations and ex situ protection of vulnerable groups.