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Okamura, Masachika*; Hase, Yoshihiro; Furusawa, Yoshiya*; Tanaka, Atsushi
Euphytica, 202(3), p.333 - 343, 2015/04
Times Cited Count：15 Percentile：63.58(Agronomy)We investigated the effect of tissue source selection in combination with ion beam irradiation on generating flower-color mutants in Chrysanthemum morifolium. Petal and leaf tissues of the chrysanthemum cultivar YoMystery (purple flowers) were used. Somaclones regenerated from irradiated tissues were analyzed for stem length and flower color mutation. Three Gy of argon ion beams was regarded as an appropriate dose for irradiation because the resulting color mutants maintained an adequate stem length suitable for commercial use. Statistical analysis of 7,258 individuals from three separate experiments revealed that (1) somaclones from petal tissue had a higher mutation frequency (2.91%) than leaf somaclones (2.01%); (2) the effect of tissue source on the frequency of flower color mutations was significantly enhanced when combined with ion-beam irradiation in that the mutation frequency of ion-beam irradiated petal clones was 6.47%, whereas that of ion-beam irradiated leaf clones was 3.89%; and (3) the spectrum of carotenoid color mutations was remarkably increased by ion-beam irradiation in that both leaf and petal ion-beam irradiated clones had brown, red and yellow flowers in contrast to the somaclones that only produced yellow flowers. These results suggest that intentional or directed induction of flower color mutants with practical value is possible by combining tissue source selection with ion beam irradiation.
Okamura, Masachika*; Nakayama, Masayoshi*; Umemoto, Naoyuki*; Cano, E. A.*; Hase, Yoshihiro; Nishizaki, Yuzo*; Sasaki, Nobuhiro*; Ozeki, Yoshihiro*
Euphytica, 191(1), p.45 - 56, 2013/05
Times Cited Count：28 Percentile：80.31(Agronomy)A few carnation cultivars are known to display a peculiar dusky color supposedly caused by anthocyanic vacuolar inclusions (AVIs). The hereditary pattern suggests that the peculiar color is controlled by a single recessive factor tightly linked with existence of AVIs containing non-acylated anthocyanins. To diversify the peculiar color carnation, we produced a bluish purple line displaying a highly novel metallic appearance by crossbreeding. By subjecting the line to ion-beam irradiation, we generated metallic reddish purple, metallic crimson and metallic red lines. All four metallic lines did not have transcripts for anthocyanin malyltransferase. In contrast to the dusky color types, metallic lines have highly condensed AVIs and water-clear vacuolar sap in the petal adaxial epidermal cells. We demonstrated that (1) a factor generating the AVIs is inactivated anthocyanin malyltransferase gene, (2) AVIs in water-clear vacuolar sap in the adaxial epidermal cells generate the novel metallic appearance, and (3) ion beam breeding is a useful tool for increasing metallic colors by changing anthocyanin structure and the level of AVIs.
Yamaguchi, Hiroyasu*; Shimizu, Akemi*; Hase, Yoshihiro; Degi, Konosuke*; Tanaka, Atsushi; Morishita, Toshikazu*
Euphytica, 165(1), p.97 - 103, 2009/01
Times Cited Count：29 Percentile：76.38(Agronomy)We compared the effects of ion-beam and 
-ray irradiation on mutation induction in axillary buds of chrysanthemum, and analyzed the chimeric structure of the resulting mutants. Axillary buds were irradiated with carbon ions (mean LET 122 keV/
m), helium ions (9 keV/m), and rays. The lower five nodes of shoots elongating from the irradiated buds were cut one by one, and new shoots were allowed to grow. This procedure was repeated twice and flower color mutation was investigated. Chimeric structure was analyzed by comparing the flower color of mutants to that of plants regenerated from the roots. All the flower color mutants induced with rays were periclinal chimeras. In contrast, some mutants obtained with ion beams had the same flower color as that of the plants derived from the roots. This suggests that they were solid mutants, where both LI and LIII tissues were derived from the same mutated cell.
