|Budget Amount *help
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1989: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1988: ¥1,700,000 (Direct Cost: ¥1,700,000)
The objective of this study was to define the cause of infertility of ginger (Zingiber officinal Roscoe, 2n=22), to explore cultivars among collected cultivars, and to produce tetraploid ginger by tissue culture with a hope for the increase of fertility.
Karyotypes were analyzed with 18 cultivars of ginger collected from Japan, China, Australia, Peru, and countries of South east asia. All cultivars used had 2n=22 of diploid chromosome complement. They however had asymetrical karyotypes which suggest the structural changes of chromosomes such as inversion, deletion, and translocation. Irregularities during reduction divisions were analyzed with a cultivar, Sanshu. In most cells of metaphase, eleven regular bivalent chromosomes were observed I, but in anaphase I and II, bridges and fragments of chromosomes were frequently detected, suggesting the presence of inversion in some of the chromosomes. Pollen fertility of 18 cultivars ranged from 0.9 % to 21.4 %. Pollen germinability of the cult
ivars, which was examined on a artificial medium containing 1 % agar, 8 % sucrose and 100 ppm bolic acid, were very low (0 % - 0.2 %); however, pollen tubes of germinated pollen grew actively.
Shoot-tip explants with the second or third leaf primordial, which were isolated from pseudostems, were treated for 4, 8, 12 or 16 days on solid MS medium (containing 0.8 % agar) or in liquid MS medium containing 0.2 % colchicine, 3 % sucrose, 2 ppm BA and 0.05 ppm NAA. After the treatment, they were subcultured on the solid medium or in the liquid medium without colchicine. The number of tetraploid plants was greater among the plants treated and subcultured on the solid medium than among those treated and subcultured in the liquid medium. The induced tetraploid ginger had a gigas apparence with higher plant height, broader leaf blades, and larger rhizome knobes. The pollen fertility and germinability of tetraploid ginger were not yet examined because the tetraploids progressed to maturity more slowly than diploid ginger. Less