Geometric Morphology and Population Genomics Provide Insights into the Adaptive Evolution of Apis Cerana in Changbai Mountain

Abstract Background: Exploration of adaptive evolution of organisms in response to environmental change will offer us a hint to the evolutionary history of species and the underlying mechanisms of adaptation to local environments, thus guiding future conservation programmes. Before the introduction of Apis mellifera in China, Apis cerana was the only species, which could be reared in captivity to obtain products. Moreover, A. cerana in Changbai Mountain is the only ecotype in such a flora. Result: We investigated the geometric morphological features of A. cerana in Changbai Mountain by analysing 300 wing specimens from 30 populations of A. cerana in 5 geographic regions. A total of 3,859,573 high-quality SNP loci were yielded via the whole-genome resequencing of 130 individuals from 130 A. cerana geographic populations.Conclusion: Corresponding geometric morphology and population genome confirmed the outstanding evolutionary role of the A. cerana population in Changbai Mountain. Genetic differentiation at the subspecies level exists between populations in Changbai Mountain and remaining geographic regions, and a significant reduction in the effective population size and an excessive degree of inbreeding may be responsible for a substantial loss of population genetic diversity. Candidate genes potentially associated with cold environmental adaptations in populations under natural selection were identified, which may represent local adaptations in populations. Our study provided insights into the evolutionary history and adaptive characteristics of A. cerana in Changbai Mountain, as well as the scientific conservation of this population.