White Guinea yam (Dioscorea rotundata) is an important staple tuber crop in West Africa. However, its origin remains unclear. In this study, we resequenced 336 accessions of white Guinea yam and compared them with the sequences of wild Dioscorea species using an improved reference genome sequence of D. rotundata. In contrast to a previous study suggesting that D. rotundata originated from a subgroup of Dioscorea praehensilis, our results suggest a hybrid origin of white Guinea yam from crosses between the wild rainforest species D. praehensilis and the savannah-adapted species Dioscorea abyssinica. We identified a greater genomic contribution from D. abyssinica in the sex chromosome of Guinea yam and 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 improving this crop through molecular breeding.

白几内亚山药（ Dioscorea rotundata ）是西非重要的块茎作物。然而，其起源仍不清楚。在这项研究中，我们对 336 个白几内亚山药种质进行了重新测序，并使用改进的D. rotundata参考基因组序列将它们与野生薯蓣物种的序列进行了比较。与先前的研究表明D. rotundata起源于Dioscorea praehensilis的一个亚群相比，我们的结果表明白几内亚山药的杂交起源是野生雨林物种D. praehensilis和适应热带草原的物种Dioscorea abyssinica之间的杂交。我们发现D. abyssinica对几内亚山药的性染色体有更大的基因组贡献，并且在SWEETIE基因周围有广泛的基因渗入。我们的研究结果指出了几内亚山药的复杂驯化情况，并强调了野生物种作为基因供体通过分子育种改良这种作物的重要性。