著者

Chikage Umeda-Hara Hidekazu Iwakawa Misato Ohtani Taku Demura Tomoko Matsumoto Jun Kikuchi Koji Murata Masaaki Umeda

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

vol.39, no.3, pp.215-220, 2022-09-25 (Released:2022-09-25)

参考文献数

28

---

Somatic polyploidization often increases cell and organ size, thereby contributing to plant biomass production. However, as most woody plants do not undergo polyploidization, explaining the polyploidization effect on organ growth in trees remains difficult. Here we developed a new method to generate tetraploid lines in poplars through colchicine treatment of lateral buds. We found that tetraploidization induced cell enlargement in the stem, suggesting that polyploidization can increase cell size in woody plants that cannot induce polyploidization in normal development. Greenhouse growth analysis revealed that radial growth was enhanced in the basal stem of tetraploids, whereas longitudinal growth was retarded, producing the same amount of stem biomass as diploids. Woody biomass characteristics were also comparable in terms of wood substance density, saccharification efficiency, and cell wall profiling. Our results reveal tetraploidization as an effective strategy for improving woody biomass production when combined with technologies that promote longitudinal stem growth by enhancing metabolite production and/or transport.

著者

Chikage Umeda-Hara Hidekazu Iwakawa Misato Ohtani Taku Demura Tomoko Matsumoto Jun Kikuchi Koji Murata Masaaki Umeda

出版者

Japanese Society for Plant Biotechnology

雑誌

Plant Biotechnology (ISSN:13424580)

巻号頁・発行日

pp.22.0716a, (Released:2022-09-17)

参考文献数

28

---

Somatic polyploidization often increases cell and organ size, thereby contributing to plant biomass production. However, as most woody plants do not undergo polyploidization, explaining the polyploidization effect on organ growth in trees remains difficult. Here we developed a new method to generate tetraploid lines in poplars through colchicine treatment of lateral buds. We found that tetraploidization induced cell enlargement in the stem, suggesting that polyploidization can increase cell size in woody plants that cannot induce polyploidization in normal development. Greenhouse growth analysis revealed that radial growth was enhanced in the basal stem of tetraploids, whereas longitudinal growth was retarded, producing the same amount of stem biomass as diploids. Woody biomass characteristics were also comparable in terms of wood substance density, saccharification efficiency, and cell wall profiling. Our results reveal tetraploidization as an effective strategy for improving woody biomass production when combined with technologies that promote longitudinal stem growth by enhancing metabolite production and/or transport.

著者

Kihei Magishi Tomoko Matsumoto Yutaka Shimada Tohru Ikeguchi

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

Nonlinear Theory and Its Applications, IEICE (ISSN:21854106)

巻号頁・発行日

vol.13, no.2, pp.343-348, 2022 (Released:2022-04-01)

参考文献数

22

---

Word co-occurrence networks (WCNs) are a major tool used to analyze languages quantitatively. In a WCN, the vertices are words (morphemes), and the edges connect n consecutive words in a sentence on the basis of the n-gram. Most studies use WCNs transformed at n=2. In this study, we investigated the changes in the structural features of WCNs when n increases using four types of documents for eight languages. We found that WCNs with n≧ 3 reflect features of the languages that do not appear when n = 2 and that some structural features evaluated by network measures depend on the text data.

著者

松本 知子 Tomoko MATSUMOTO

出版者

長崎国際大学

雑誌

長崎国際大学論叢 = Nagasaki International University Review (ISSN:13464094)

巻号頁・発行日

vol.17, pp.63-73, 2017-03

---

英語のコミュニケーション能力向上のための指導法についてはこれまで多く議論されてきたが、文法指導とコミュニカティブな学習とを統合する指導法についてはあまり議論されていない。これはコミュニケーション能力が文法の基礎力なしで向上することを暗示していると捉えられるかもしれない。また、このような見方で学習をする学習者は、文法学習を機械的な暗記による活動として捉えかねない。本研究は、「情報や考えを理解し、適切に伝えるコミュニケーション能力」の向上を目的とし、効果的なコミュニカティブ文法指導法について考察する。さらに、学習者にとって文脈の理解が助けとなる映画を利用した指導法について述べる。具体的には、過去形の「コア」である距離感に焦点をあて、助動詞 will と would や wonder を使った構文と wondered や was wondering を使った構文の丁寧さの度合いを理解できる方法について言及する。最後に、過去形のコアを活用して仮定法過去の指導法についても述べる。