Development of a New Melon Cultivar ‘Ibaraking’ with High Fruit Growth Ability under Low Temperature Conditions, High Total Soluble Solid Content, and Resistance to Fusarium Wilt

‘Ibaraking’ is a new F1 melon (Cucumis melo L.) cultivar with green-fleshed fruit, high fruit growth ability under low-temperature conditions, high total soluble solid (TSS) content, and a long shelf life. It was developed from a cross between 2 parental lines P2 and P32 at the Plant Biotechnology Institute, Ibaraki Agricultural Center, Ibaraki, Japan. The parental line, P2, was fixed by self-pollination of a line selected from somaclonal variants of a cultivar ‘Andes,’ while another line, P32, was fixed by self-pollination of a cultivar ‘Earl’s Seine Natsu 2.’ The fruit characteristics of ‘Ibaraking’ were compared with those of the common melon semi-forcing culture cultivars ‘Andes-5’ and ‘Otome,’ from 2005 to 2007, in semi-forcing culture by creeping cultivation. In ‘Ibaraking,’ low-temperature fruit growth ability and external appearance were equal to those of ‘Otome’ and exceeded those of ‘Andes-5,’ while the TSS content was similar to that of ‘Andes-5’ and exceeded that of ‘Otome.’ With regard to shelf life, ‘Ibaraking’ was superior to ‘Otome’ and equal to ‘Andes-5.’ In response to Fusarium wilt of melon, the most severe melon disease, ‘Ibaraking’ demonstrated resistance to races 0 and 2. These responses were identical to those of ‘Andes-5’ and ‘Otome.’ Therefore, we conclude that ‘Ibaraking’appears a more suitable cultivar in semi-forcing culture by creeping cultivation in Ibaraki prefecture, Japan.