Variation in inbreeding depression and plasticity across native and non-native field environments

Area of Science:

• Evolutionary Ecology
• Population Genetics
• Environmental Adaptation

Background:

• Research on genetic variation in phenotypic plasticity and the role of environment on inbreeding depression has expanded.
• An emerging question is how these mechanisms interact in novel environments, crucial for understanding population establishment in response to climate change and human-assisted transport.

Purpose of the Study:

• To investigate the interaction between inbreeding depression and phenotypic plasticity in novel environments.
• To understand population establishment and adaptation in response to environmental changes.

Main Methods:

• Comparison of outcrossed and inbred lines of Mimulus guttatus across multiple field sites (native, novel native, novel non-native).
• Evaluation of inbreeding depression (survival, reproduction, biomass) and phenotypic plasticity (stem diameter, plant height) in nearly 6500 individuals.

Main Results:

• Inbreeding depression varied significantly across sites; outcrossed offspring generally outperformed selfed offspring.
• Self-progeny performed better or equally well as outcross progeny in a native-novel site.
• Significant phenotypic plasticity and genetic variation in plasticity were detected, with marked differences between home and non-native novel sites. Evidence for an interaction between inbreeding and plasticity was found for stem diameter.

Conclusions:

• Inbreeding depression and phenotypic plasticity vary among field sites during initial population establishment, influencing responses to environments outside a species' current range.
• The interaction between inbreeding and plasticity is limited and environment-dependent, suggesting complex adaptive responses in novel environments.