Genetic differentiation within multiple common grassland plants supports seed transfer zones for ecological restoration

Abstract

Summary1. Ecological restoration of grasslands is increasingly based on regional seeds derived from predefined seed transfer zones. However, the degree and spatial pattern of genetic differentiation among provenances of different seed transfer zones is largely unknown. 2. We assessed the genetic differentiation among eight out of 22 German seed transfer zones for seven common grassland species (Arrhenatherum elatius, Centaurea jacea, Daucus carota, Galium album, Hypochaeris radicata, Knautia arvensis and Lychnis flos-cuculi) using AFLP markers. We analysed genetic population structure with AMOVA and Bayesian cluster analysis and tested for isolation by distance and isolation by environment. 3. In all of the investigated species, almost all pairs of provenances were genetically differentiated. Bayesian cluster analysis revealed species-specific numbers and spatial patterns of gene pools, with between two (Arrhenatherum) and eight clusters (Lychnis). Most investigated seed transfer zones represented a unique gene pool in the majority of the species. 4. We found isolation by distance in four species, isolation by environment, driven by climatic seasonality, in three species, and a lack of both in three species. Thus, the observed genetic differentiation appears to be caused by both neutral and adaptive processes. 5. Synthesis and applications. Our study shows that grassland plants are indeed strongly genetically differentiated across Germany supporting the strategy of seed transfer zones for ecological restoration. Although the predefined seed transfer zones are unlikely to match the exact genetic structure of many species, they serve their purpose by capturing a substantial amount of intraspecific genetic variation across species.

Genetic differentiation and regional adaptation among seed origins used for grassland restoration: lessons from a multispecies transplant experiment

“…The only species with a high P ST in fitness‐related traits was Knautia , a species that turned out to occur as both diploid and tetraploids in our study (Durka et al . ). Plants with different ploidy levels are known to show different vigour and fitness (Otto & Whitton ).…”

“…; see also Durka et al . () for more details). This makes some sense, since the eight regions represent larger biogeographical units and may thus have some important adaptations in common.…”

The European Native Seed Industry: Characterization and Perspectives in Grassland Restoration

“…To implement the use of local seed origins, the geographic delineation of seed zones, within which seeds are to be collected, propagated and sown, may be critical [18,19]. In Europe, the first attempts to delineate national seed zones for herbaceous plants have been made only recently [19].…”

“…In Europe, the first attempts to delineate national seed zones for herbaceous plants have been made only recently [19]. The definition of transnational seed zones may be crucial [2] to ensure ecological adaptation of plant species instead of the current fixation on administrative borders that often bear little relevance in an ecological or biological sense.…”

A Climate-Oriented Approach to Support Decision-Making for Seed Provenance in Ecological Restoration

“…However, this information has been mostly obtained for commercial or dominant tree species (e.g., Gray et al, 2011;Isaac-Renton et al, 2014;Steane et al, 2017b). Only recently have efforts been made to establish genetic-based seed transfer zones for key species used in restoration, but information is generally limited for most species and regions (Clair et al, 2013;Durka et al, 2017; see also Table 1 in Bower et al, 2014).…”