Phylogenetic relationships, breeding implications, and cultivation history of Hawaiian taro (Colocasia esculenta) through genome-wide SNP genotyping

Taro, Colocasia esculenta, is one of the world’s oldest root crops and of particular economic and cultural significance in Hawai‘i, where historically more than 150 different landraces were grown. We developed a genome-wide set of more than 2400 high-quality single nucleotide polymorphism (SNP) markers from 70 taro accessions of Hawaiian, South Pacific, Palauan, and mainland Asian origins, with several objectives: (a) uncover the phylogenetic relationships between Hawaiian and other Pacific landraces, (b) shed light on the history of taro cultivation in Hawai‘i, and (c) develop a tool to discriminate among Hawaiian and other taros. We found that almost all existing Hawaiian landraces fall into five monophyletic groups that are largely consistent with the traditional Hawaiian classification based on morphological characters, e.g., leaf shape and petiole color. Genetic diversity was low within these clades but considerably higher between them. Population structure analyses further indicat...