Genetic Diversity in Taro (Colocasia esculenta)

Taro [Colocasia esculenta (L.) Schott] is an ancient, tropical root crop that is morphologically diverse with over 10,000 landraces. It is the fifth most produced root crop in theworld and is mainly grown in tropical Africa, China, NewGuinea, and many Pacific islands. Taro typically is grown for its starchy corm (i.e., underground stem), although leaves and flowers also are eaten as vegetables. There is controversy over its geographic center of origin, but this is likely to be in the Indo-Malayan area. Evidence indicates that it was domesticated, possibly independently, across an area that ranges from northeast India to Yunnan province in China to New Guinea. Within Micronesia and Polynesia, where taro is a staple crop, the genetic base is very narrow. Genetic diversity within the taro germplasm is significantly greater in Asia and New Guinea. The exploitation of this diversity could lead to the development of cultivars with greater disease resistance, and improved yields and corm quality. Taro is a neglected crop in terms of recent advances in molecular biology, with only a limited number of studies utilizing next-generation transcriptome and genome sequencing. At present, a high-quality reference genome is lacking; however, recent genotyping-by-sequencing (GBS) approaches promise to improve our understanding of taro genetics.