TROPAG CONFERENCE 31 October – 2 November 2022 Brisbane, Australia
Dr Angelique D’Hont
Dr Angélique D’Hont, Team Manager and Researcher, CIRAD French Agricultural Research Centre for International Development, France
Angélique D’Hont’s research interests are focused on understanding the structure and evolution of complex genomes involving polyploidy, interspecific hybridity and structural heterozygosity. She is leading a research team ‘Genome structure and evolution’ at CIRAD , Montpellier, France with current activities focused mainly on banana and sugarcane, two polyploid complexes, making use of comparative genomics, molecular marker diversity, genetic mapping and molecular cytogenetics. These studies are closely connected with genetic improvement programs. She coordinated the production and analysis of the first reference genome assembly for banana and sugarcane. Currently, she is focusing with her team in deciphering banana and sugarcane genome diversity through re-sequencing approaches.
Plenary presentation: Wednesday 2 November 2022
Banana genome diversity is shaped by admixture and large structural variations
Banana is a major crop that derives from hybridizations between Musa species and subspecies that diverged in Southeast Asian regions and archipelagos. Diploid and triploid hybrids with seedless parthenocarpic fruits were selected by humans and thereafter dispersed through vegetative propagation. We sequenced 162 accessions, including banana cultivars and representatives of Musa diversity, in Illumina WGS. Several ancestral groups were identified as contributors to these cultivars, including one species not previously shown to be largely involved and two uncharacterized genetic pools that have yet to be identified. Representative alleles from these genetic pools revealed complex genome mosaics involving three to seven contributors in diploid and triploid cultivars. These results shed new light on the origin and domestication of banana cultivars. In addition, using the sequence data and genotyping-by-sequencing data from 11 progenies, we characterized seven large reciprocal chromosome translocations and showed that they emerged in different ancestral groups of Musa. Most diploid and triploid cultivars analyzed were structurally heterozygous for 1 to 4 translocations. All translocations induced a recombination reduction of variable intensity and extent. The translocated chromosomes were found preferentially transmitted in many cases, this may have favored their colonization. Impact of genome architecture on genetic analysis of agronomic traits will be illustrated.