Plants adaptive variation

During their evolution, plants have coped with environmental changes by migration and local adaptation to new environments. Resilience through evolution is a common feature of forest tree species, manifested as wide variation in traits such as photoperiod, temperature and water availability. In natural populations of forest tree species in central and northern Europe, patterns of differentiation in quantitative traits and local adaptation have been established since post-glacial recolonisation. However, the genetic basis of local adaptation and the role of natural selection, drift and population history in maintaining variation at the genomic level remain poorly understood. In my collaborative research I look at the molecular evolution of adaptive variation in European distribution of forest tree species of great ecological and economical importance namely Scots pine (Pinus sylvestris L.) and the taxa from the Pinus mugo complex (P. mugo T., P. uliginosa N., P. uncinata R.). The major focus of the study is to search for genomic regions and SNPs involved in their local adaptation and to resolve the extent to which the population processes of migration, selection and demography contribute to maintain divergence in natural populations.

Population history and phylogeography

Successful detection of molecular signature of local adaptation and ecological divergence requires parallel evaluation of evolutionary and demographic processes, as both shape genetic variation in natural populations. However, neutral demographic events affect all genes in a similar way. Therefore loci under selection can be detected by contrast with background genetic variation. In my research I use neutral markers including microsatellites and nucleotide polymorpisms (SNPs) at a controled genomic regions to study patterns of background genetic variation accross populations.

Hybridization and speciation

Natural hybridisation is an important process that creates recombinants from interspecific mating between divergent parental taxa where they come into geographic contact. It may cause the swamping of the species with the smaller effective population size by gene flow from the more abundant species, integration of genetic material from one species into another through repeated back-crossing (introgression), homoploid hybrid speciation – in which the new hybrid lineages become reproductively isolated from parental populations and finally, the transfer of adaptive traits across species boundaries. Associations among alleles of one species in the genetic background of a close relative provide compelling evidence of recent introgression. In my research I apply molecular population genetics and genomics methods to study the genetic basis of reproductive isolation and adaptive divergence of hybrid plants in contact zones of pine species.  Many species has different mode of inheritance of organellar genomes (bi-parentaly inherited nuclear DNA, maternally inherited mtDNA and paternally inherited cpDNA).  Polymorphic sites detected in different genomes could be used for development of markers for tracking gene flow at intra- and interspecific level. Those markers can be useful for barcoding and identification of cryptic species.

Novel genomic approaches for forest tree breeding and conservation

I am interested in development and application of novel conservation genetics and breeding approaches in forest trees that are based on recent developments in cost-effective high-throughput marker technologies. Those genomic selection based methods take advantage of a large number of markers for predicting breeding values of populations for genetic improvement programmes especially in non-model plant species such as forest trees. Predictions of environmental change, including surface temperature and precipitation patterns, indicate that currently optimal forest tree phenotypes may suffer a fitness deficit in the near future. Such fitness loss can impact forest productivity and mortality rates worldwide influencing seedling recruitment, productivity, susceptibility to fire, pathogens or insect attack. This scenario is particularly challenging, as forest trees constitute ~82% of terrestrial biomass and harbour more than 50% of terrestrial biodiversity providing wood material and fundamental ecosystem services for humans including preservation of biodiversity, the global carbon cycle, climate regulation and preservation of water quality. All of these are strongly dependent on the health, structure and functioning of forests. Emerging concerns about how trees will adapt to rapid climate changes provide a strong impetus to improve our understanding of the genomic basis of adaptation and hence the adaptive potential of trees. Such knowledge is particularly valuable for conservation, restoration and management of natural populations and to provide tools for genetic improvement programmes.