Insights from Genome Sequencing of Cassava and other Manihot

We characterized cassava genetic diversity via whole genome shotgun sequencing of 58 accessions, including a global collection of cassava, wild relatives (Manihot esculenta ssp. flabellifolia), and other Manihot. We confirm and date the whole-genome duplication that occurred prior to the split between Manihot and Hevea, and date the M. esculenta—M. glaziovii divergence. We find widespread interspecific admixture that raises questions about the nature of Manihot species, and we show that an M. glazioviihaplotype is shared between cassava accessions whose ancestry can be traced back to the Amani program of the 1930's. By examining a panel of 268 African cassava accessions we reveal that this haplotype is enriched among improved cassava varieties.

Progress on cassava genome assembly version 7, based on PacBio sequencing; and draft assemblies for M. esculenta ssp. flabellifolia and M. glaziovii, will be presented. Large-scale structural genomic variation between cassava, M. esculenta ssp. flabellifolia, and M. glaziovii will be explored.