Understanding the interactions of co-occurring species within and across trophic levels provides key information needed for understanding the ecological and evolutionary processes that underlie biological diversity. As genetics has only recently been integrated into the study of community-level interactions, the time is right for a critical evaluation of potential new, gene-based approaches to studying communities. Next-generation molecular techniques, used in parallel with field-based observations and manipulative experiments across spatio-temporal gradients, are key to expanding our understanding of community-level processes. Here, we introduce a variety of '-omics' tools, with recent studies of plant-insect herbivores and of ectomycorrhizal systems providing detailed examples of how next-generation approaches can revolutionize our understanding of interspecific interactions. We suggest ways that novel technologies may convert community genetics from a field that relies on correlative inference to one that reveals causal mechanisms of genetic co-variation and adaptations within communities.

We used Double Digest Restriction site associated DNA sequencing (ddRAD) and Miseq to develop new geographically informative nuclear and plastid SNP and indel loci in Quercus robur and Q. petraea. Genotypes derived from sequence data of 95 individuals and two pools of 20 individuals each of Q. robur and Q. mongolica covering the distribution range of the species, were analysed to select geographically informative and polymorphic loci within Germany and Russia. We successfully screened a selected set of 431 nuclear single nucleotide polymorphism (nSNP), six nuclear Indel, six mitochondrial single nucleotide polymorphism (mtSNP) and ten chloroplast single nucleotide polymorphism (cpSNP) loci with a SeqSNP genotyping platform on 100 individuals Quercus petraea from 10 locations in Germany, 100 individuals Quercus robur from ten locations in Germany and 100 individuals Quercus robur from ten locations in Russia. The newly developed loci are useful for species identification and genetic studies on the genetic diversity and genetic differentiation of Quercus robur and Quercus petraea in Europe.

We developed a new set of 25 nuclear (nc), 12 chloroplast (cp) and 7 mitochondrial (mt) SNPs and used it to genotype 371 Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) trees from seven locations in a 200 km by 400 km area in the Russian Far East. One of the locations in an area of 15 km by 25 km east of the city Ussuriusk was analyzed more intensively with 188 collected trees. The genetic differentiation at the nuclear SNPs was small to moderate and for the plastid SNPs it was high when considering all trees from the seven locations. The gene pool distances between locations were for 19 out of 21 pairs statistically highly significant. There was no correlation of genetic and spatial distances. Only three different multilocus-haplotypes could be identified and 42 two-loci-combinations of plastid SNPs could be used to identify them. Conclusions for the practical application such as timber tracking and gene conservation are discussed.

Violation of CITES regulations in tropical timber trade necessitates the development of accurate species identification systems. The application of available methods, mostly based on visual illustrations and descriptions of wood anatomical characteristics, proved to be difficult or even impossible, particularly on lower taxonomic levels. Further, because most of the chain-of-custody documents are externally applied marks which can easily be manipulated, control methods should be based on wood features which are inherent in the wood itself. In a case study on five closely-related genera of the Meliaceae (mahogany) family, including Swietenia sp. (listed on CITES appendix II), Khaya, Entandrophragma, and Carapa sp. (legal trade timbers), this study demonstrates the process of developing DNA markers for identification purposes. A detailed sequence analysis of several non-coding cpDNA regions resulted in an assay of seven genus-specific SNP (single nucleotide polymorphism) markers. Tools have been designed that could be applied with lowcost equipment on the basis of PCR-RFLPs without the need for sequencing or capillary electrophoresis techniques. In addition, the application of the method to wood material with degraded DNA of low overall quantity is highlighted.