TY - JOUR T1 - Revisiting the Origin of the Octoploid Strawberry JF - bioRxiv DO - 10.1101/665216 SP - 665216 AU - Aaron Liston AU - Na Wei AU - Jacob Tennessen AU - Junmin Li AU - Ming Dong AU - Tia-Lynn Ashman Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/06/11/665216.abstract N2 - The cultivated strawberry, Fragaria Ă—ananassa, originated in France approximately 270 years ago via hybridization between two wild species introduced from North and South America. Both the cultivated strawberry and its parental species are octoploids with 2n=8x=56 chromosomes. In the recent publication of the genome of the cultivated strawberry, the authors present a novel phylogenetic hypothesis, proposing that each of the four subgenomes originated from a different 2n=2x=14 diploid progenitor. They further suggest that the hexaploid species Fragaria moschata was a direct ancestor of the strawberries. We reanalyzed the four octoploid subgenomes in a phylogenomic context, and found that only two extant diploids were progenitors, a result that is consistent with several previous studies. We also conducted a phylogenetic analysis of genetic linkage-mapped loci in the hexaploid F. moschata, and resolved its origin as independent of the octoploids. We identified assumptions in their tree-searching algorithm that prevented it from accepting extinct or unsampled progenitors, and we argue that this is a critical weakness of their approach. Correctly identifying their diploid progenitors is important for understanding and predicting the responses of polyploid plants to climate change and associated environmental stress. ER -