カキ‘西条’における雄花の発見

‘Saijo’ persimmon (Diospyros kaki Thunb.) is a local cultivar in western Japan and a signature agricultural product in Shimane Prefecture. ‘Saijo’ fruit has excellent eating quality with high sugar content, and long history of the cultivation. However, ‘Saijo’ has many problems, such as fruit softening and short shelf-life. The improvement of this cultivar by breeding techniques will contribute to overcome these problems and revitalize the fruit industry in region where it is cultivated. ‘Saijo’ normally set only female flowers which are pistillate flowers without stamens. The bud sports which can bear male flowers with functional stamens were found in commercial orchards in Shimane. The fertile anthers produce viable pollens which germinate on agar media containing sucrose, and the pollens could be used for the artificial self-pollination of ‘Saijo’. The male flowers of ‘Saijo’ open up new possibilities for the cultivar improvement. Moreover, the shoots with male flowers on ‘Saijo’ are scientifically interesting materials to reveal the mechanism of sex determination in persimmons.