Population genetic differentiation and phenotypic plasticity of Ambrosiaartemisiifolia under different nitrogen levels

Abstract

Rapid adaptive evolution and phenotypic plasticity are two mechanisms that are often thought to underlie invasiveness of alien plant species, but whether they can co‐occur within invasive plant populations under altered environmental conditions such as nitrogen (N) enrichment has seldom been explored. Latitudinal clines in plant trait responses to variation in environmental factors may provide evidence of local adaptation. Here, we inferred the relative contributions of phenotypic plasticity and local adaptation to the performance of the invasive plant Ambrosia artemisiifolia under different soil N levels, using a common garden approach. We grew A. artemisiifolia individuals raised from seeds that were sampled from six invasive populations along a wide latitudinal cline in China (23°42'N to 45°43'N) under three N (0 g N·m‐2, 5 g N·m‐2, and 10 g N·m‐2) levels in a common garden. Results show significant interpopulation genetic differentiation in plant height, number of branches, total biomass, and transpiration rate of the invader A. artemisiifolia across the N treatments. The populations also expressed genetic differentiation in basal diameter, growth rate, leaf area, seed width, root mass, above‐ground biomass, stomatal conductance, and intercellular CO2 concentration regardless of N treatments. Moreover, plants from different populations of the invader displayed plastic responses in time to flowering, hundred‐grain weight, net photosynthesis rate, and relative biomass allocation to roots and shoots and seed length under different N treatments. Additionally, individuals of A. artemisiifolia from higher latitudes grew shorter and allocated less biomass to the roots regardless of N treatment, while latitudinal cline (or lack thereof) in other traits depended on the level of N in which the plants were grown. Overall, these results suggest that rapid adaptive evolution and phenotypic plasticity in the various traits that we quantified may jointly contribute to invasiveness of A. artemisiifolia under different levels of N availability. More broadly, the results support the idea that phenotypic plasticity and rapid adaptive evolution can jointly enable invasive plants to colonize a wide range of environmental conditions.

Directional and stabilizing selection shaped morphological, reproductive, and physiological traits of the invader Solidago canadensis

“…For some exotic plant species, both local adaptation and phenotypic plasticity may jointly facilitate invasion. For instance, both local adaptation and phenotypic plasticity were linked to successful invasion by Wedelia trilobata (Asteraceae) (Si et al, 2014 ), A. artemisiifolia (Xiong et al, 2023 ), and Prunella vulgaris (Lamiaceae) (Godoy et al, 2010 ). It is likely that phenotypic plasticity and local adaptation both underlie the invasiveness of S. canadensis .…”

“…For some exotic plant species, both local adaptation and phenotypic plasticity may jointly facilitate invasion. For instance, both local adaptation and phenotypic plasticity were linked to successful invasion by Wedelia trilobata (Asteraceae) (Si et al, 2014), A. artemisiifolia (Xiong et al, 2023),…”

Perspectives of invasive alien species management in China

“…While local adaptation and phenotypic plasticity in functional traits are potential influencers of the invasiveness of alien plants, their relative contributions remain uncertain. According to Xiong et al (2023), adaptive evolution and phenotypic plasticity in various traits may work in synergy to enhance the invasiveness of Ambrosia artemisiifolia in China under varying nitrogen levels. Their results showed that both phenotypic plasticity and rapid adaptive evolution could enable invasive plants to thrive across diverse environmental conditions.…”