Local Citrus Genetic Resources and Their Polymethoxyflavones Content in Northern Part of Okinawa Island

Research on Amami-Oshima Island, Tokunoshima Island, the northern part of Okinawa Island, and Iriomote Island reveals that local citrus varieties, particularly Shikuwasa (Citrus depressa) and Kabuchi (C. keraji), exhibit high levels of polymethoxyflavones (PMFs). These compounds, including nobiletin, tangeretin, and sinensetin, vary in composition across different citrus species, enabling classification into distinct groups such as Shikuwasa, Kabuchi, and Oto (C. oto). The study analyzed 30 native citrus trees, identifying both indigenous varieties and introduced species like Daidai (C. aurantium) and Kununbo (C. nobilis), while also noting cases of synonymy or homonymy among them. This work provides foundational data for genetic resource conservation and utilization in these UNESCO World Heritage Sites.

Inafuku-Teramoto, S., Yamamoto, M., Kinjyo, H., Kitajima, A., Wada, K., & Kawamitsu, Y. (2010). Local Citrus Genetic Resources and Their Polymethoxyflavones Content in Northern Part of Okinawa Island. Horticultural Research (Japan), 9(3), 263–271. https://doi.org/10.2503/hrj.9.263