Begonia contains 1820 species and is amongst the world’s largest angiosperm genera. The genus has a pantropical distribution, characterised by extremely high rates of narrow endemism. The distribution of Begonia species richness is representative of rainforest diversity generally, being markedly greater in the Neotropics and tropical Asia, and suggests the family is a good proxy for investigating tropical diversification. Much of the research into the generation of large-scale patterns of tropical diversity has focused on trees, however herbaceous layer genera such as Begonia represent an ecologically contrasting aspect of tropical vegetation and need to be included if we are to have a complete understanding of tropical ecosystems. The prevalence of Begonia across the tropics suggests a highly successful strategy in exploiting the niches available to tropical herbs. In order to understand the generation of such a large radiation, we need insights into the interplay of niche evolution, physiology and genome evolution, building on the foundations of a sound taxonomy and robust phylogenetic hypotheses. Preliminary phylogenetic hypotheses for Begonia have been constructed, based on a small number of genome regions. Insights from next generation approaches need to be explored to show us what extent these represent species trees in the light of data on hybridisation and organelle capture. In addition we need to understand the degree of niche differentiation between species with respect to both phylogeny and genomic evolution. In this symposium we aim to bring together a variety of disciplines to give insight into the evolution of Begonia diversity, drawing on recent advances in research of niche evolution, genome dynamism, reproductive biology, photosynthetic physiology, biogeography, and management of biodiversity data. The building of a synthetic picture of evolution in the mega-diverse genus Begonia has the potential to provide a template for understanding broader patterns tropical herbaceous diversity.
Photosynthesis is a foundational process that supports biodiversity in the vast majority of ecological communities on our planet, including those inhabiting water-limited environments. Many plants employ modified forms of photosynthesis that increase their water-use efficiency under extreme environmental conditions. Crassulacean acid metabolism (CAM) is one such innovation that has facilitated diversification in a wide array of plant lineages. Multiple evolutionary transitions from C3 to CAM photosynthesis have had a major impact on primary productivity and biodiversity in water-limited terrestrial habitats, and over 6% of extant flowering employ CAM. Recent comparative investigations of the molecular basis for CAM physiology in distinct plant lineages are advancing understanding of CAM evolution, and these advances have important implications for engineering of more efficient water use in plant species being grown in water-limited environments. This symposium will showcase how comparative and functional genomics research are revealing both shared and lineage-specific evolutionary paths to the origin of CAM in diverse plant lineages.
Algae represent a large group of different organisms from different phylogenetic groups, representing many taxonomic divisions. In general algae can be referred to as plant-like organisms that are usually photosynthetic and aquatic, but do not have true roots, stems, leaves, vascular tissue and have simple reproductive structures. This symposium will have 6 presentations from scholars in several important areas of algal studies. Topics such as the phylogeny, diversification, and ecological aspects of diatoms, whole genome and proteome study of a filamentous cyanobacterium, the biosynthesis and transcriptional regulation of secondary metabolites and environmental aspects of water blooms will be discussed.