Genetic Variation of European Beech Populations and Their Progeny from Northeast Germany to Southwest Switzerland

Markus Müller,Konstantin Krutovsky,Sarah Seifert,Laura Cuervo-Alarcon,Rajendra K.C,Oliver Gailing,Matthias Arend,Meena Chhetri,Reiner Finkeldey

doi:10.3390/f9080469

Abstract

Climate change can adversely affect the growth of European beech (Fagus sylvatica L.) across its entire distribution range. Therefore, knowledge of the adaptive potential of this species to changing climatic conditions is of foremost importance. Genetic diversity is the basis for adaptation to environmental stress, and the regeneration phase of forests is a key stage affecting genetic diversity. Nevertheless, little is known about the effect of climate change on the genetic diversity of adult trees compared to their progeny. Here, we present genetic diversity data for 24 beech populations ranging from northeast Germany to southwest Switzerland. Potentially adaptive genetic variation was studied using single nucleotide polymorphism (SNP) markers in candidate genes that are possibly involved in adaptive trait variation. In addition, more than 2000 adult trees and 3000 of their seedlings were genotyped with simple sequence repeat (SSR) markers to determine selectively neutral genetic diversity and differentiation among populations. All populations showed high SSR and SNP variation, and no differences in genetic diversity were found between adult trees and their offspring. The genetic differentiation between adults and seedlings within the same stands was also insignificant or very low. Therefore, we can conclude tentatively that the transfer of genetic variation among tree generations, currently, is not much affected by climate change, at least in the studied beech populations.

Highlights

Climate change has different effects on forests, such as a prolonged vegetation season [1], increased tree mortality, or altered productivity [2,3,4,5]
European beech has a high genetic diversity, revealed in different studies based on various genetic markers, such as isozymes, microsatellites or simple sequence repeats (SSRs), single nucleotide polymorphisms (SNPs) and amplified fragment-length polymorphisms (AFLPs) [14,15,16,17]
The lowest allelic richness (AR ) for the seedlings was found in CH-W-Chamoson (AR = 5.4) and the highest in DE-GS

Summary

Introduction

Climate change has different effects on forests, such as a prolonged vegetation season [1], increased tree mortality, or altered productivity [2,3,4,5]. A reduced growth of European beech (Fagus sylvatica L.), one of the economically and ecologically most important forest tree species in Europe, was observed. Climate change might influence the reproductive phenology of trees, and negatively affect the quantity and quality of seeds [18,19]. Regeneration is a key stage affecting genetic diversity in natural forests [20], and different studies revealed a negative impact of climate change on the regeneration of different tree species including beech in some areas [21,22,23,24]. Westergren et al [25]

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Discussion

Conclusion