Beware of Ogres: grass pea and the challenges of assembling large legume genomes

Peter Emmrich

Peter Emmrich, John Innes Centre & BecA-ILRI Hub


Grass pea (Lathyrus sativus) is a highly nutritious legume crop with outstanding resilience to both drought and flooding. The relative lack of genetic and genomic resources for this orphan crop has stifled efforts to develop safe and highly productive varieties. Using Illumina HiSeq and Oxford Nanopore PromethION data we have assembled drafts of the 6.3 Gbp grass pea genome — the largest legume genome sequenced to date. Long-read sequencing is helping us to overcome the challenge of this genome’s highly repetitive nature, particularly of large Ogre-type repeats, which limit the usefulness of short-read-based scaffolding. Our new genome and transcriptome sequences are opening the path to nutritionally improved, resilient grass peas for Sub-Saharan Africa and South Asia.


Peter Emmrich is a plant scientist focusing on improving orphan legumes to help agriculture in tropical areas become more resilient in the face of the climate crisis. His background is in plant metabolic biology but is fascinated by the potential of genomics to help us rapidly domesticate underused crops. Peter works for the John Innes Centre but is based at the BecA-ILRI Hub in Nairobi.