ID: 613 / 163

Category: Symposia

Track: Pending

Proposed Symposium Title: DYSPLOIDY, DIPLOIDISATION AND DIVERSIFICATION: IMPACT OF POST-POLYPLOID GENOME RESTRUCTURING ON SPECIES AND TRAIT DIVERSITY

Abstract: Whole genome duplication (WGD), or polyploidy, is pervasive across the angiosperm tree of life, and has occurred persistently throughout their evolutionary history, from the origin of angiosperms up to present day neo-polyploidisation events in genera of many disparate plant groups. Whilst WGDs are not unique or restricted to flowering plants, the angiosperms are perhaps unique in terms of genome rearrangement post-polyploidy. This genome restructuring, through the fusion and reduction of chromosomes (dysploidy), as well as genome downsizing, results in smaller diploid-like genomes that are reduced in size but often complex in their rearrangement. These processes can be collectively referred to as diploidisation. Following diploidisation are recurrent cycles of polyploidy in many angiosperm groups, and this leads to the obscure situation of Arabidopsis that with n = 5 chromosomes, should be at least 48-ploid. It is perhaps diploidisation itself that holds the key to the evolutionary success of angiosperms, rather than polyploid per se, and the process of genome rearrangement that is crucial to adaptive success and persistence. By investigating plant groups in which these processes are happening currently, and in very recent evolutionary time, we may be able to unpick stochastic vs. adaptive drivers for genome restructuring post-polyploidisation. In this symposium the aim is to stimulate a dialogue amongst researchers on these topics, including not just detailed genomic rearrangements, but also the proximate results of diploidisation such as increases in species richness, morphological variation and ecological adaptation.

Speaker 1: Mark W. Chase Department of Environment and Agriculture, Curtin University, Perth, Western Australia, Australia m.chase@kew.org ‘Genomic and morphological characteristics of a diverse post-polyploid radiation in Australia’

Speaker 2: Luiz A. Cauz-Santos Department of Botany and Biodiversity Research, University of Vienna, Austria luiz.cauz@univie.ac.at ‘Phylogenomics, biogeography and population dynamics of Nicotiana section Suaveolentes’

Speaker 3: Steven Dodsworth School of Biological Sciences, University of Portsmouth, Portsmouth, UK steven.dodsworth@port.ac.uk ‘Use of long-read technologies to probe a very recent chromosomal rearrangement’

Topics (Up to three): Phylogenetics and Phylogenomics

Topic 2: Comparative Genomics / Transcriptomics

Topic 3: Macroevolution

Justification: All angiosperms have been impacted by cycles of polyploidisation in their evolutionary history. Despite this, comparatively less is known about the diploidisation process, that results in diploid-like plant genomes that then experience further rounds of polyploidy. In this symposium we aim to focus on genomic, ecological and macroevolutionary aspects of the diploidisation part of this key cycle, which will be of key interest to many researchers in the fields of systematics and plant genome evolution.