Abstract
A genecological approach was used to explore genetic variation in adaptive traits in Pseudoroegneria spicata, a key restoration grass, in the intermountain western United States. Common garden experiments were established at three contrasting sites with seedlings from two maternal parents from each of 114 populations along with five commercial releases commonly used in restoration. Traits associated with size, flowering phenology, and leaf width varied considerably among populations and were moderately correlated with the climates of the seed sources. Pseudoroegneria spicata populations from warm, arid source environments were smaller with earlier phenology and had relatively narrow leaves than those from mild climates with cool summers, warm winters, low seasonal temperature differentials, high precipitation, and low aridity. Later phenology was generally associated with populations from colder climates. Releases were larger and more fecund than most of the native ecotypes, but were similar to native populations near their source of origin. Differences among native populations associated with source climates that are logical for survival, growth, and reproduction indicate that genetic variation across the landscape is adaptive and should be considered during restoration. Results were used to delineate seed transfer zones and population movement guidelines to ensure adapted plant materials for restoration activities.
Highlights
Genecology is the study of intraspecific genetic variation in relation to source environments, a term first used by Swedish evolutionary biologist Go€te Turesson (1923)
Natural selection is suggested when populations differ in putative adaptive traits, those differences are correlated with characteristics of the source environments, and the relationship between a trait and an environmental character is logical for growth, survival, or reproduction
The R2 values found in the current study are similar in magnitude to those found for two genecology studies of grass species over a more restricted area in the Blue Mountains: E. glaucus with R2 values between 0.51 and 0.30 for the first four principal components (PCs) (Erickson et al 2004) and B. carinatus with R2 values between 0.46 and 0.40 for the first two PCs (Johnson et al 2010a,b)
Summary
Genecology is the study of intraspecific genetic variation in relation to source environments, a term first used by Swedish evolutionary biologist Go€te Turesson (1923). Strong and interpretable correlations between geographic genetic variation as revealed in common garden studies and the environments in which populations evolved suggest adaptation as determined by natural selection (Heslop-Harrison 1964; Endler 1986). Natural selection is suggested when populations differ in putative adaptive traits, those differences are correlated with characteristics of the source environments, and the relationship between a trait and an environmental character is logical for growth, survival, or reproduction. One practical advantage of genecology studies is the ability to evaluate a large number of populations from a wide range of source environments in one or a few accessible common gardens. Large numbers of populations are useful in highly heterogeneous
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call