論文ID: MI-080
‘Hasshu’, a dwarf budsport that originated from the leading persimmon cultivar ‘Hiratanenashi’ (Diospyros kaki Thunb.), was discovered in Japan in 2005. Although ‘Hiratanenashi’ is seedless because of anisoploidy (2n = 135 = 9x), ‘Hasshu’ produces some small normal seeds. In this study, we investigated differences in the morphological characteristics of the vegetative organs and fruits and in the ploidy level between ‘Hasshu’ and ‘Hiratanenashi’. The shoot length, internode length, and leaf size of ‘Hasshu’ were smaller than those of ‘Hiratanenashi’. ‘Hasshu’ bore smaller flowers than those of ‘Hiratanenashi’ in late May, and had consistently smaller fruit than ‘Hiratanenashi’ at all fruit development stages. ‘Hasshu’ ripened in late October, similar to ‘Hiratanenashi’. Both ‘Hiratanenashi’ and ‘Hasshu’ are pollination-variant astringent (PVA) cultivars. Except for the deletion of one allele at ssrdk10, no differences were detected between the two cultivars at four simple sequence repeat (SSR) marker loci. By flow cytometric analysis and chromosome observation, we confirmed that ‘Hasshu’ was octoploid (2n = 120 = 8x), indicating that it was both a dwarf and a ploidy-reduction mutation. These results suggest that recovery of the ability to produce some normal seeds by ‘Hasshu’ may have been caused by the change in ploidy from anisoploid to isoploid.
