In situ marker‐based assessment of leaf trait evolutionary potential in a marginal European beech population

Abstract

Evolutionary processes are expected to be crucial for the adaptation of natural populations to environmental changes. In particular, the capacity of rear edge populations to evolve in response to the species limiting conditions remains a major issue that requires to address their evolutionary potential. In situ quantitative genetic studies based on molecular markers offer the possibility to estimate evolutionary potentials manipulating neither the environment nor the individuals on which phenotypes are measured. The goal of this study was to estimate heritability and genetic correlations of a suite of leaf functional traits involved in climate adaptation for a natural population of the tree Fagus sylvatica, growing at the rear edge of the species range. Using two marker-based quantitative genetics approaches, we obtained consistent and significant estimates of heritability for leaf phenological (phenology of leaf flush), morphological (mass, area, ratio mass/area) and physiological (δ(13)C, nitrogen content) traits. Moreover, we found only one significant positive genetic correlation between leaf area and leaf mass, which likely reflected mechanical constraints. We conclude first that the studied population has considerable genetic diversity for important ecophysiological traits regarding drought adaptation and, second, that genetic correlations are not likely to impose strong genetic constraints to future population evolution. Our results bring important insights into the question of the capacity of rear edge populations to evolve.

How do functional traits syndromes covary with growth and reproductive performance in a water‐stressed population of Fagus sylvatica?

“…Another hypothesis is that phenology itself alters the leaf morphological traits. On the other hand, in a companion study (Bontemps et al ), we found a significant genetic basis for budburst phenology and δ 13 C (less evidence for LMA) which suggests that the presence of genetic correlations cannot be excluded, and that the observed pattern of resource‐conservative traits versus resource‐exploitative traits can be the consequence of selection.…”

“…). Because vegetative reproduction occurs through suckering or resprouting in F. sylvatica , we checked for the presence of clones using genetic analysis (Bontemps et al ). We found 26 pairs of individuals with the same genotype and only kept the biggest individual within each genet, leading to a total of 149 focal non‐clonal dominant trees (Fig.…”

Phenotypic trait variation measured on European genetic trials of Fagus sylvatica L

“…A complete network of genetic trials is also of interest for the conservation of genetic resources, in particular those from marginal populations which can hold higher genetic variation than those populations at the core of a distribution 7 . Finally, we hope that this database will encourage researchers and foresters to compile and publish genetic trial data of other species, since databases such as this are an invaluable resource helping us understand the capacity of forests to adapt and acclimatise to climate change.…”

Abiotic genetic adaptation in the Fagaceae

“…and Paxon) Schottky in China (Shi & Chen ), in F. sylvatica at its north‐eastern natural distribution limit (Kempf & Konnert ), as well as at the rear edge of the species range (Bontemps et al . ) and in Quercus ilex L. populations growing at the northern distribution limit of the species (Vernesi et al . ).…”