Genome analyses reveal the hybrid origin of the staple food crop white Guinea yam

Abstract White Guinea yam ( Dioscorea rotundata ) is an important staple tuber crop of West Africa. However, its origin remains unclear. In this study, we re-sequenced 336 accessions of white Guinea yam and compared them with the sequences of the wild Dioscorea species using an improved reference genome sequence of D. rotundata . Our results suggest a hybrid origin of white Guinea yam from crosses between the rainforest wild species D. praehensilis and the savannah-adapted D. abyssinica . We identified a higher genomic contribution from D. abyssinica in the sex chromosome of Guinea yam and an extensive introgression around the SWEETIE gene. Our findings point to a complex domestication scenario for Guinea yam and highlight the importance of wild species as gene donors for improvement of this crop through molecular breeding.