title: Efficient haploid and doubled haploid production from unfertilized ovule culture of gentians (Gentiana spp.).
abstract: Factors affecting reliable plant regeneration from unfertilized ovule culture of gentians (Gentiana spp.) were examined. Cold pretreatment (4°C) of flower buds enhanced or maintained production of embryo-like structure (ELS). When 43 genotypes were surveyed in two different labs, 40 of them produced ELSs ranging from 0.01 to 26.5 ELSs per flower bud. No ELSs could be obtained in three genotypes. A significant correlation (r = 0.64) was observed between the number of ELS per flower and the frequency of responding flower buds. Eight genotypes of G. triflora, which were used as common materials in two different labs, produced ELSs in both labs. The ploidy levels of a total of 1,515 regenerated plantlets were determined, revealing that the majority of these plants consisted of haploids (57.9%) and diploids (34.3%). However, the frequency of haploids and diploids was different between G. triflora and G. scabra, and G. triflora showed higher frequencies of haploids than G. scabra. When haploids were treated with oryzalin for chromosome doubling, diploids and tetraploids were obtained. These results demonstrate that the unfertilized ovule culture technique of gentians is a powerful tool for obtaining haploids and DHs because of its reproducible and reliable nature and application to a wide range of genotypes.
authors.affiliation: Faculty of Agriculture, Iwate University , 3-18-8 Ueda, Morioka, Iwate 020-8550 , Japan.
authors.forename: Hisako
authors.initials: H
authors.lastname: Doi
authors.affiliation: Iwate Agricultural Research Center (IARC) , 20-1 Narita, Kitakami, Iwate 024-0003 , Japan.
authors.forename: Nobue
authors.initials: N
authors.lastname: Hoshi
authors.affiliation: Iwate Biotechnology Research Center , 22-174-4 Narita, Kitakami, Iwate 024-0003 , Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Yamada
authors.affiliation: Faculty of Agriculture, Iwate University , 3-18-8 Ueda, Morioka, Iwate 020-8550 , Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Yokoi
authors.affiliation: Iwate Biotechnology Research Center , 22-174-4 Narita, Kitakami, Iwate 024-0003 , Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nishihara
authors.affiliation: Hachimantai City Floricultural Research and Development Center , 70 Hachimantai, Iwate 028-7592 , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hikage
authors.affiliation: Faculty of Agriculture, Iwate University , 3-18-8 Ueda, Morioka, Iwate 020-8550 , Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Takahata
keywords: G. scabra; Gentiana triflora; doubled haploid; genotype; haploid; unfertilized ovule culture