Abstract
Alpine habitats, characterized by their high degree of environmental heterogeneity and harsh climatic conditions, support a diverse array of plants with unique adaptive strategies. However, the mechanisms underlying the formation of these adaptive strategies, as well as their intrinsic links to species diversification, remain unclear. In this study, we investigated the evolution of life history traits, fruit characteristics, and variation in the karyotype of alpine species, and their roles in shaping their adaptability to high-altitude environments. We performed a comprehensive analysis of trait diversification, adaptive trait evolution, and their associations with environmental factors in the genus Meconopsis on the Qinghai-Xizang Plateau. Our results revealed that ancestral floral traits were characterized by solitary inflorescences and blue-purple pigmentation, features that have re-evolved at multiple points throughout the evolutionary history of the genus. We found that increased ploidy levels promoted perennial growth and semelparity (single-time fruiting), suggesting that life history strategies and fruiting frequency are strongly coupled. Furthermore, karyotypic variation and abiotic factors such as altitude, soil pH, and climate were found to accelerate the evolution of a perennial fruiting reproductive strategy. Our findings provide new insights into the evolution of adaptive traits in alpine plants and reveal how these species adjust their life history strategies in response to environmental pressures. Our findings enhance our understanding of resource allocation trade-offs in plants in extreme environments and shed light on the relationship between species diversification and adaptive evolution in alpine ecosystems.