The scale of local adaptation in Mimulus guttatus: comparing life history races, ecotypes, and populations

Abstract

SummaryFitness trade-offs between environments are central to the evolution of biodiversity. Although transplant studies often document fitness trade-offs consistent with local adaptation (LA), many have also found an advantage of foreign genotypes (foreign advantage (FA)). Understanding the mechanisms driving the magnitude and distribution of fitness variation requires comparative approaches that test the ecological scales at which these different patterns emerge.We used a common garden transplant experiment to compare the relative fitnesses of native vs foreign genotypes at three nested ecological scales within Mimulus guttatus: annual vs perennial life history races, perennial ecotypes across an elevational range, and populations within perennial elevational ecotypes. We integrated fitness across the life-cycle and decomposed LA vs FA into contributions from different fitness components.We found LA, measured as home-site advantage, between annual and perennial races and a trend towards LA among populations within montane habitats. Conversely, we found strong FA of low-elevation perennials in a montane environment.LA between life history races reflects the fitness advantages of adult survival and vegetative growth in a mesic environment. Within the perennial race, recent climate conditions or nonselective processes, such as dispersal limitation or mutational load, could explain FA of lowelevation perennials in a montane environment.

Experimental migration upward in elevation is associated with strong selection on life history traits

“…First, we classified populations as either annual or perennial based on duration in the field (i.e., senescence at fruit maturity); annuals tend to occur at lower elevations (range: 293-1,693 m a.s.l.) These four life history groups are well separated in a principal components analysis of trait variation ( Figure S2) and also differed in their relative fitness in the common garden experiment (Peterson et al, 2016). ; Table S1).…”

“…We transplanted seedlings from these 11 populations into a common garden field experiment over two years (Peterson et al, 2016). The site of the common garden was a montane meadow in Stanislaus National Forest, CA (N 38.32107, W 119.91607, 2,040 m a.s.l.…”

“…In this study, we use trait and fitness data from a common garden field experiment in which annual and perennial populations across an elevation transect were transplanted into a high-elevation montane meadow (Peterson, Kay, & Angert, 2016). In this study, we use trait and fitness data from a common garden field experiment in which annual and perennial populations across an elevation transect were transplanted into a high-elevation montane meadow (Peterson, Kay, & Angert, 2016).…”

“…In this study, we use trait and fitness data from a common garden field experiment in which annual and perennial populations across an elevation transect were transplanted into a high-elevation montane meadow (Peterson, Kay, & Angert, 2016). In a previous analysis of this experiment, we found that lower-elevation perennials outperformed local montane perennials, suggesting the potential for upward-elevation shifts in this system (Peterson et al, 2016). In a previous analysis of this experiment, we found that lower-elevation perennials outperformed local montane perennials, suggesting the potential for upward-elevation shifts in this system (Peterson et al, 2016).…”

Transcriptome Analysis of a Cultivar of Green Perilla (<I>Perilla frutescens</I>) Using Genetic Similarity with Other Plants via Public Databases

“…In addition, pathogens which infect plants are often species-specific; thus, a plant may possess a response mechanism that corresponds to the pathogen. Unlike green perilla, M. guttatus is adapted to live in riparian and wetland environments (Peterson et al, 2016). Given these differences, green perilla and M. guttatus could possess different response mechanisms against disease and wounding.…”