Red-purple flower due to delphinidin 3,5-diglucoside, a novel pigment for Cyclamen spp., generated by ion-beam irradiation

摘要

We previously bred fragrant cyclamen cultivars by interspecific hybridization between cultivars of Cyclamen persicum and the wild species Cyclamen purpurascens. One of these fragrant cultivars, Kaori-no-mai, blooms purple flowers containing malvidin 3,5-diglucoside as the major anthocyanin. Here, we irradiated etiolated petioles of Kaori-no-mai with a 320-MeV carbon-ion beam at 0-16 Gy to increase flower color variation by mutation. Some of the M 2 plants derived from self-pollination of M 1 plants irradiated at 2 Gy were flower-color mutants that retained desirable flower shape, flower size, and leaf color. One of the mutants bloomed novel red-purple flowers, the major anthocyanin of which was delphinidin 3,5-diglucoside. Loss of methylation activity at the anthocyanin 3' -and 5'-hydroxyl groups with little influence on anthocyanin concentration was attributed to the mutation. Because the major anthocyanins in flowers of Cyclamen spp. were previously restricted to malvidin, peonidin, and cyanidin types, the generation of a cyclamen containing mostly the delphinidin-type anthocyanin is an important breakthrough in cyclamen breeding. We expect this mutant to become not only a commercial cultivar itself, but also a valuable genetic resource for cyclamen breeding.