Opportunities for unlocking the potential of genomics for A frican trees

Trees (or their absence) represent one of the most defining features of landscapes on the African continent. However, they face major threats including habitat loss and degradation, invasive alien species, disturbance from frequent fire, over-harvesting, pollution, changes in pollinators or dispersers populations, and climate change (Balmford et al., 2001; Davies et al., 2011). Understanding how trees respond to these impacts would require an integrative approach of which genomic science has a potentially major role to play (Plomion et al., 2016). Since the advent of genomic science, its investigative power has been exploited for trees in temperate regions, particularly involving members ofPinus,Picea,Pseudotsuga,Populus,Eucalyptus,Quercus, Castanea, Malus, Prunus, and Fraxinus (Neale & Kremer, 2011; Neale et al., 2013). These species serve as models for exploring various processes in molecular genetics, functional biology, evolutionary biology, phenotypic and genotypic adaptation, physiology and organismal development (Tuskan et al., 2006; Plomion et al., 2016). Although the tropics have exceptionally high tree diversity –with Africa alone having c. 50 timesmore native tree species than temperate Europe (Slik et al., 2015) – tree genomic research in this region lags behind that of temperate ones. Limited funding and the lack of reference genomes for tropical trees have limited the progress of genomic science on the African continent. With over 6000 tree species on the African continent (Slik et al., 2015), there is a need to establish reference genomes for the major tree families. First, we discuss ways to exploit next generation sequencing (NGS) technologies including genotyping by sequencing (GBS), de novo transcriptome assembly and whole genome sequencing to generate genomic resources for nonmodel tree species on the African continent. Second, we discuss landscape genomics, an emerging field in genomic science and discuss research areas in which the genomic resources of trees inAfrica can be used to inform research on landscape genomics and to improve food production.