TY - JOUR

T1 - Climate and land use affect genetic structure of Stipa glareosa P. A. Smirn. in Mongolia

AU - Oyundelger, Khurelpurev

AU - Ritz, Christiane M.

AU - Munkhzul, Oyunbileg

AU - Lang, Birgit

AU - Ahlborn, Julian

AU - Oyuntsetseg, Batlai

AU - Römermann, Christine

AU - Wesche, Karsten

PY - 2020/5

Y1 - 2020/5

N2 - In dry steppes, strong climatic constraints, especially highly variable precipitation, and grazing are the most important factors controlling plant life. Growth is strongly limited by water availability, while grazing may affect species presence and performance. However, there is a lack of studies on population genetics of dryland plants in general, and of those addressing grazing effects in particular. To determine the landscape-scale genetic structure of dryland species, and if grazing has an impact on that, we chose the Eurasian steppe grass Stipa glareosa for a population genetic study employing nine polymorphic Simple Sequence Repeat (SSR) markers. We assessed genetic fingerprints of 200 individuals from six populations in Mongolia, which were sampled along a large-scale precipitation and altitudinal gradient. Nested within this gradient, sub-populations were sampled along short local transects representing different grazing intensities. Overall, S. glareosa populations showed rather low levels of genetic diversity at a mean Bruvo distance among individuals within a given population of 0.494 (mean expected heterozygosity He = 0.053). Linear mixed model analysis implied that genetic diversity was affected by both climatic constraints and local grazing conditions. We found a moderate isolation-by-distance pattern across all populations; grazing additionally influenced the genetic structure at local scale. Analysis of Molecular Variance revealed a modest genetic differentiation between populations (9 % of variation) and among sub-populations representing different grazing levels (11 %). Moreover, we detected indicator alleles that were exclusive for populations along the precipitation gradient; other alleles were associated with certain grazing levels across all populations. Thus, our data suggest that climatic constraints affect the genetic structure of S. glareosa populations, while at local scales differences in grazing disturbance may also matter.

AB - In dry steppes, strong climatic constraints, especially highly variable precipitation, and grazing are the most important factors controlling plant life. Growth is strongly limited by water availability, while grazing may affect species presence and performance. However, there is a lack of studies on population genetics of dryland plants in general, and of those addressing grazing effects in particular. To determine the landscape-scale genetic structure of dryland species, and if grazing has an impact on that, we chose the Eurasian steppe grass Stipa glareosa for a population genetic study employing nine polymorphic Simple Sequence Repeat (SSR) markers. We assessed genetic fingerprints of 200 individuals from six populations in Mongolia, which were sampled along a large-scale precipitation and altitudinal gradient. Nested within this gradient, sub-populations were sampled along short local transects representing different grazing intensities. Overall, S. glareosa populations showed rather low levels of genetic diversity at a mean Bruvo distance among individuals within a given population of 0.494 (mean expected heterozygosity He = 0.053). Linear mixed model analysis implied that genetic diversity was affected by both climatic constraints and local grazing conditions. We found a moderate isolation-by-distance pattern across all populations; grazing additionally influenced the genetic structure at local scale. Analysis of Molecular Variance revealed a modest genetic differentiation between populations (9 % of variation) and among sub-populations representing different grazing levels (11 %). Moreover, we detected indicator alleles that were exclusive for populations along the precipitation gradient; other alleles were associated with certain grazing levels across all populations. Thus, our data suggest that climatic constraints affect the genetic structure of S. glareosa populations, while at local scales differences in grazing disturbance may also matter.

KW - Altitude

KW - Genetic diversity

KW - Grazing

KW - Microsatellite

KW - Precipitation

KW - Steppe

KW - Ecosystems Research

UR - http://www.scopus.com/inward/record.url?scp=85083550020&partnerID=8YFLogxK

U2 - 10.1016/j.flora.2020.151572

DO - 10.1016/j.flora.2020.151572

M3 - Journal articles

AN - SCOPUS:85083550020

VL - 266

JO - Flora

JF - Flora

SN - 0367-2530

M1 - 151572

ER -