Trait variation in response to varying winter temperatures, diversity patterns and signatures of selection along the latitudinal distribution of the widespread grassland plant Arrhenatherum elatius

Abstract

Across Europe, genetic diversity can be expected to decline toward the North because of stochastic and selective effects which may imply diminished phenotypic variation and less potential for future genetic adaptations to environmental change. Understanding such latitudinal patterns can aid provenance selection for breeding or assisted migration approaches. In an experiment simulating different winter temperatures, we assessed quantitative trait variation, genetic diversity, and differentiation for natural populations of the grass Arrhenatherum elatius originating from a large latitudinal gradient. In general, populations from the North grew smaller and had a lower flowering probability. Toward the North, the absolute plastic response to the different winter conditions as well as heritability for biomass production significantly declined. Genetic differentiation in plant height and probability of flowering were very strong and significantly higher than under neutral expectations derived from SNP data, suggesting adaptive differentiation. Differentiation in biomass production did not exceed but mirrored patterns for neutral genetic differentiation, suggesting that migration‐related processes caused the observed clinal trait variation. Our results demonstrate that genetic diversity and trait differentiation patterns for A. elatius along a latitudinal gradient are likely shaped by both local selection and genetic drift.

Phenotypic plasticity closely linked to climate at origin and resulting in increased mortality under warming and frost stress in a common grass

“…This notion might often be correct, but costs of phenotypic plasticity (DeWitt et al, ) and the fact that phenotypic plasticity may be adaptive, maladaptive, or neutral with regard to an individual's fitness (Ghalambor et al, ) should always be kept in mind. Maladaptive or nonadaptive plastic changes might occur as a result of stress (Gotthard et al, ; Grether, ; Merila & Hendry, ; Michalski et al, ; Teplitsky et al, ). Our case study provides clear evidence for maladaptive phenotypic plasticity as mortality increased with phenotypic plasticity, that is, increased variation in leaf biomass production and root integrity was largely caused by an increased mortality in response to winter warming and frost (Figure ).…”

“…Genetic impoverishment and increased drift toward the north have been described for A. elatius (Michalski et al, 2017). Selecting the more diverse linages from the south for assisted migration Vitt, Havens, Kramer, Sollenberger, & Yates, 2010) as management action in face of climate change has been suggested to improve adaptive potential (Michalski et al, 2017). Root integrity (Bush et al, 2016;Oney, Reineking, O'Neill, & Kreyling, 2013;Valladares et al, 2014).…”

“…However, phenotypic plasticity comes with costs (DeWitt, Sih, & Wilson, ) and may be adaptive, maladaptive, or neutral with regard to an individual's fitness, that is, phenotypic plasticity can also prevent adaptation under certain conditions (Ghalambor et al, ). Maladaptive or nonadaptive plastic changes might occur as a result of stress, and evidence from some case studies also suggests reduced performance with increasing phenotypic plasticity (Gotthard, Nylin, & Nylin, ; Grether, ; Merila & Hendry, ; Michalski, Malyshev, & Kreyling, ; Teplitsky, Mills, Alho, Yarrall, & Merila, ).…”

Natural selection contributes to geographic patterns of thermal plasticity in Plantago lanceolata

“…However, neutral processes, for example, genetic drift with limited gene flow, can also produce divergence, particularly in populations with small effective population sizes, N e (Lande, ; Wright, ). Currently, there is a need to assess the relative importance of selection versus neutral processes at large geographic scales (Bragg, Supple, Andrew, & Borevitz, ; Kawakami et al, ; Kleynhans, Mitchell, Conlong, & Terblanche, ; Michalski, Malyshev, & Kreyling, ; Orsini, Vanoverbeke, Swillen, Mergeay, & Meester, ; Walisch, Colling, Bodenseh, & Matthies, ). Such information not only helps us to understand how evolutionary processes have molded current geographic patterns of phenotypic diversification, the information also helps us better predict how climate change will alter current geographic patterns.…”

“…2011; Kleynhans, Mitchell, Conlong, & Terblanche, 2014;Michalski, Malyshev, & Kreyling, 2017;Orsini, Vanoverbeke, Swillen, Mergeay, & Meester, 2013;Walisch, Colling, Bodenseh, & Matthies, 2015).…”