Secondary metabolite diversity in taro, Colocasia esculenta (L.) Schott, corms

Taro, Colocasia esculenta (L.) Schott, is one of the oldest major staple food crops of tropical regions. This study represents one the first in-depth surveys of taro biodiversity based on corms flesh secondary metabolites fingerprints. Out of the 167 analyzed cultivars, 70 UV-absorbing substances were annotated according to their retention time, UV/vis absorption spectrum, high resolution mass (by HRMS) and fragmentation pattern (tandem MS-MS). They included 6 carotenoids, 35 flavones/flavonols, 6 flavanones, 2 flavanols and 1 indol. Twenty flavones that were glycosylated forms of apigenin, luteolin and chrysoeriol conferred to the corms a yellow color and defined a low abundance (ca. 10% of cultivars) chemotype. Their accumulation negatively correlated with flavanones which were annotated for the first time in taro. Orange flesh corms were characterized by high levels of β-carotene. Secondary metabolite-based chemotypes displayed no geographical distribution pattern.