Papers - ISHIGAKI Genki
-
Nishiwaki A., Mizuguti A., Kuwabara S., Toma Y., Ishigaki G., Miyashita T., Yamada T., Matuura H., Yamaguchi S., Lane Rayburn A., Akashi R., Ryan Stewart J.
American Journal of Botany 98 ( 1 ) 154 - 159 2011.1
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：American Journal of Botany
Premise of the study: Looming petroleum shortages and projected negative impacts of human-induced climate change may be partly alleviated by the development and use of bioenergy feedstock crops. Miscanthus × giganteus, a highly productive sterile triploid hybrid grass that was discovered in Japan several decades ago, has considerable potential as an alternative source of energy. Given the risks, however, involved in the reliance upon production of one clone of this hybrid, which is a natural cross between Miscanthus sacchariflorus and Miscanthus sinensis, for lignocellulosic bioenergy production, natural occurrences of triploidy were investigated in sympatric populations of tetraploid M. sacchariflorus and diploid M. sinensis in Japan. Methods: Seeds were counted and DNA content was estimated by flow cytometry for plants of M. sacchariflorus and M. sinensis in several sympatric populations throughout Japan. Chromosomes were also counted for select plants. Key results: Based on seed-set data, M. sacchariflorus has significantly lower seed set than M. sinensis in Japan. Putative triploid seeds were found on M. sacchariflorus plants in southern Japan. Conclusions: This is the first report of the natural occurrence of Miscanthus triploid plants in several decades. If found to be sterile and similar in productivity to the commonly cultivated clone of M. × giganteus, these triploid plants might serve as additional sources of genetic variation for bioenergy production. Seed set data also indicates that other triploid plants might be found in more northern regions of Japan. © 2011 Botanical Society of America.
DOI： 10.3732/ajb.1000258
-
Estimation of genome size in Brachiaria species Reviewed
Ishigaki G, Gondo T, Ebina M, Suenaga K, Akashi R
Grassland Science 56 ( 4 ) 240 - 242 2010.12
Language：English Publishing type：Research paper (scientific journal)
-
Ishigaki Genki, Gondo Takahiro, Suenaga Kazuhiro, AKASHI Ryo
Grassland science 55 ( 3 ) 164 - 170 2009.9
Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Japanese Society of Grassland Science
-
Ishigaki G., Gondo T., Suenaga K., Akashi R.
Grassland Science 55 ( 1 ) 46 - 51 2009.8
Authorship：Lead author Language：English Publishing type：Research paper (scientific journal) Publisher：Grassland Science
We have established a plant regeneration system via multiple shoot formation, or somatic embryogenesis from seed-derived shoot apical meristems of ruzigrass (Brachiaria ruziziensis). Shoot apices as initial explants were isolated from aseptically germinated seedlings, and cultured in vitro. The most effective treatments for multiple shoots and embryogenic calli formation were 0.5 mg L-1 2,4-dichlorophnoxyacetic acid (2,4-D) plus 2.0 mg L-1 6-benzylaminopurine (BAP) and 4.0 mg L-1 2,4-D plus 0.2 mg L-1 BAP, respectively. Plant regeneration from multiple shoot-clumps was achieved by culturing on solid MS medium containing 1.0 mg L-1 BAP or 2.0 mg L-1 kinetin plus 2.0 mg L-1 gibberellic acid. Somatic embryos regenerated plantlets on a MS medium without plant hormones. Regenerated shoots were germinated precociously on MS medium containing 0.01 or 0.1 mg L-1 naphthalene acetic acid and 2.0 mg L-1 BAP. All regenerants were successfully grown up to maturity. The plant regeneration via multiple-shoot clumps and embryogenic calli formation can be used as an alternative regenerable target tissue for genetic transformation using particle bombardment of ruzigrass. © Journal Compilation © 2009 Japanese Society of Grassland Science.