Demographic modeling reveals simultaneous radiation and genetic-morphological discordance in Asian eggplant (Solanum melongena L.) landraces: evolutionary insights into geography and anthropogenic selection

Information from the abstract

The domestication history and spatial expansion of the cultivated eggplant ( Solanum melongena L.) in Asia have been debated due to conflicting hypotheses regarding a monocentric versus polycentric origin. Furthermore, relying on morphology to reconstruct this history is problematic given the species’ extensive phenotypic plasticity. To resolve these evolutionary uncertainties, we integrated phenotypic and microsatellite data from 373 landraces (855 individuals) across 12 Asian countries to evaluate the respective roles of neutral genetic drift, geographic isolation, and anthropogenic selection. Our analysis supported South Asia as the primary center of origin and identified Thailand and China as secondary diversity hubs. We observed a clear discordance between neutral genetic structure and morphological differentiation. Genetic clusters reflect geographic isolation, whereas phenotypic variation is primarily driven by divergent anthropogenic selection for regional cultural preferences. Through demographic model testing based on approximate Bayesian computation, we rejected a simple linear stepping-stone dispersal scenario. The modeling supported a simultaneous radiation framework, indicating a rapid and concurrent divergence of East and Southeast Asian lineages from a South Asian ancestral population approximately 2,800 years ago. Additionally, historical gene flow estimates indicated an ancient Pan-Asian metapopulation connected by early trade networks. This historical connectivity contrasts sharply with the low contemporary migration rates that characterize modern isolated gene pools. This simultaneous radiation model provides a demographic framework that helps reconcile previous conflicting findings on eggplant domestication. The study suggests human-mediated dispersal and cultural selection have acted as major forces shaping rapid spatial radiation and phenotype-genotype decoupling, offering a quantitative basis for understanding the evolutionary dynamics of cultivated species.

Why this record is monitored

This record has an Impact Signal of 83/100 based on recency, source, collaboration, and bibliographic signals. It prioritizes monitoring and is not a judgment of research quality.

Related topics: Genetic diversity and population structure · Genetic Mapping and Diversity in Plants and Animals · Genetic and Environmental Crop Studies