Format: ORAL

Pablo Muoz-Rodrguez1,2 John R.I. Wood3 Tom Wells2,3 Bethany R.M. Williams2 Tom Carruthers4 Robert W. Scotland2

1. Universidad Complutense de Madrid, Madrid, Spain. 2. University of Oxford, Oxford, United Kingdom. 3. Royal Botanic Gardens, Kew, London, United Kingdom. 4. University of Michigan, Ann Arbor, Michigan, United States.

Sweet potato (Ipomoea batatas (L.) Lam.) is a top ten food crop worldwide. Cultivated in all tropical and subtropical regions of the world, it is a hexaploid species with a complex evolutionary history. Dozens of studies have tried to untangle its origin since the 19th century, but they accumulated as much useful information as error. This was due to a poor understanding of the relationship between sweet potato and its wild relatives, poorly defined species boundaries, and lack of robust phylogenies. In summary, the lack of a good taxonomic knowledge has hindered progress in sweet potato research. Herbarium specimens are an extraordinary resource for molecular data. However, the optimal use of these data requires a decisive, parallel taxonomic effort. We have dedicated the last ten years to investigating the origin and evolution of sweet potato in the context of a taxonomic monograph of Ipomoea. During this time, we have studied c. 30,000 herbarium specimens with molecular sequence data from c. 3,000 specimens Sanger sequencing, HybSeq and whole genome sequencing. This enabled important results pertaining to sweet potato, including species delimitation, the identification of sweet potato closest diploid and tetraploid wild relatives, or their differentiation from modern hybrids. In this talk, we will discuss the role and importance of herbarium specimens and herbariomics in our work, as part of a taxonomic monograph and with a focus on sweet potato. We will discuss our previous results and ongoing work on the origin, evolution and domestication of this important crop, and will highlight the importance of integrating genomics and taxonomy using herbarium specimens to accelerate tropical plant diversity studies.