Influence of Management and Habitat on Genotypic and Phenotypic Diversity of Dactylis glomerata

Abstract

Although the importance of grassland habitats as a reservoir of genetic resources is generally recognized, little is known about the effect of environmental factors and agricultural land use on genotypic and phenotypic diversity in grassland ecosystems. This study aimed to investigate orchardgrass (Dactylis glomerata L.), a perennial forage grass well adapted to a broad range of temperate environments as a model species to assess the effect of management practices (intensive, extensive) and farming systems (organic, non-organic) on genotypic and phenotypic diversity. Twenty orchardgrass populations were sampled from Swiss permanent grassland habitats, contrasting in respect to organic and conventional farming systems, management intensity and environmental conditions. Genetic diversity was analyzed using 29 simple sequence repeat markers (SSRs) and 10 morpho-physiological traits evaluated in a field experiment. Nei’s unbiased gene diversity (HE) revealed a high genetic diversity (0.51–0.56). Most of the genetic variation resided within populations (96.06 %). Genetic diversity was significantly influenced by intensification of management resulting in a decrease of genotype diversity within sites (r = −0.50, p = <0.05). Furthermore, phenotype evaluation revealed significant influence of management on Dactylis glomerata populations based on selected traits. However, within- and between-population genotypic and phenotypic diversity was only marginally correlated with faming systems. Facing uncertain climatic changes and an increasing need for sustainable management of resources, the insights gained may be particularly valuable for the in situ conservation of valuable genetic resources of grassland species. Furthermore, they support targeted selection of ecotypes for breeding programs.