Polymethoxylated Flavone Content of Major Cultivars and Local Accessions of Citrus Cultivated in Kagoshima, Japan

抄録

In this study, we cultivated 32 major citrus cultivars and local accessions of Kagoshima and one control accession to elucidate the polymethoxylated flavone contents with the purpose of providing information for citrus consumers to promote citrus production in the region. All trees were grafted on trifoliate orange rootstock and cultivated in Kagoshima City, Japan. In general, the Brix values and fruit weights of the major cultivars were higher and heavier than those of the local accessions. The ascorbic acid content of Tankan and Rokugatsu Mikan was high and that of Shiikuwasha, Kabuchii, and Shiikuu was very low. For analysis of polymethoxylated flavones (PMF), important health-promoting components sinensetin, nobiletin, heptamethoxyflavone, and tangeretin were quantified. Cultivar and accession differences in the PMF content were also observed. Nobiletin and tangeretin were found to be major PMF in most accessions, and heptamethoxyflavone was not detected in some species such as Kishu Mikan, Ponkan, Shiikuwasha, and Kuroshima Mikan. In the major cultivars, the PMF contents of Kishu Mikan, Ponkan, and Tankan were found to be high. In the local citrus accessions, Shiikuwasha, its relative, and Kishu Mikan were found to have the highest PMF content, and those of Kabuchii and Kuroshima Mikan were also high. Major cultivars Satsuma mandarin, pummelo, and its relative and the local accession Kunenbo contained little PMF.