Research on the Phylogeographic Patterns and Environmental Adaptability of Wild Apricot in Xinjiang

As the wild progenitor population of cultivated apricots, Xinjiang wild apricots hold irreplaceable significance in maintaining ecosystem functions and conserving germplasm resources. This study employed a combined approach utilising chloroplast DNA fragments (rpl32-trnL and ndhC-trnV) and a single-copy nuclear gene (DXH) to conduct a systematic phylogeographic analysis of wild apricot resources within the Ili wild fruit forests of Xinjiang. Results indicate significant divergence between genetic structures revealed by chloroplast DNA and nuclear genes, reflecting complex evolutionary processes driven by natural selection, genetic drift, and gene flow across distinct genetic systems. Genetic variation predominantly resided within populations, with weak differentiation between them. Neutrality tests and mismatch analysis indicated that wild apricot maternal lineages had not undergone significant historical expansions, suggesting a possible shared population contraction (bottleneck effect). Conversely, nuclear gene data supported recent expansion, with the Yining County population exhibiting the most pronounced expansion signal, indicating effective recording of this event by the nuclear genome. Niche modelling using the MaxEnt approach indicates that key environmental factors influencing wild apricot distribution include precipitation during the wettest season (100~135 mm), precipitation during the warmest season (90~120 mm), and soil sand content (6%~38%). The current suitable habitat is primarily concentrated in the Ili Kazakh Autonomous Prefecture, while projections under future climate scenarios indicate an expansion trend in its suitable range. This study systematically elucidates the genetic diversity characteristics and phylogeographic patterns of Xinjiang wild apricot, clarifying its population history dynamics and future distribution potential. It provides theoretical foundations and practical guidance for the scientific conservation and sustainable utilisation of germplasm resources for this species.