著者

Emi Kameoka Shiro Mitsuya Roel R. Suralta Akira Yamauchi Amelia Henry

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.17, pp.45-58, 2023 (Released:2023-08-14)

参考文献数

44

被引用文献数

1

---

In this study, two experiments were conducted to evaluate the genotypic variation of rice root system distribution and root activity in response to short-term drought conditions. Seven rice genotypes were used, of which one (Rexmont) showed the greatest reduction in shoot biomass under drought, and two (Swarna and KDML105) showed the least reduction in shoot biomass under drought in both experiments. In a phytotron experiment (Experiment 1) in which root hydraulic conductivity (Lpr) of 21-day-old rice plants was evaluated in well-watered (control) and dry down (drought) conditions, the Lpr of Swarna, KDML105, and IRAT109 were significantly lower under drought compared to the control. In a field experiment (Experiment 2) conducted in the 2013 wet season at IRRI, stomatal conductance, bleeding rate, and root surface area density (RSAD) at 0-15, 15-30, 30-45, and 45-60 cm soil depths were measured in an irrigated (control) and rainfed (drought) treatments. Swarna, KDML105, and FR13A showed significant reductions in RSAD at 0-30 cm depth under drought in the field compared to the control, while Rexmont and IRAT109 showed no significant changes. In addition, Rexmont and Swarna both maintained higher bleeding rates than the other genotypes. Based on the root hydraulic and architectural traits of contrasting genotypes, we conclude that the bleeding rate did not explain the genotypic variations in the maintenance of shoot biomass, and that reducing shallow root growth and Lpr in response to drought conferred the best ability to maintain shoot biomass under short-term drought conditions.

著者

Gisela Grunewaldt-Stöcker Christiane von den Berg Johanna Knopp Henning von Alten

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.7, pp.33-48, 2013 (Released:2013-09-20)

参考文献数

76

被引用文献数

19

---

Plant protection against soil-borne diseases has been a challenge in horticultural production of Ericaceae for a long time. We tested the hypothesis that ericoid mycorrhizal fungi (ERMF) control root pathogens. Isolates of ERMF previously obtained from Calluna vulgaris and Rhododendron hirsutum were selected based on growth inhibiting activity against Oomycetes in dual agar plate tests. In addition, we assessed their impact on economically important Pythium spec. and Phytophthora cinnamomi in sterile Rhododendron plantlets in a liquid culture system, which is suitable for continuous observations of the infection process. For this purpose, rooted cuttings of micro-propagated Rhododendron plantlets were transferred to a mineral solution and subsequently inoculated with either Oidiodendron maius or the ERMF isolates. Before the root pathogens were applied to the experimental system, the symbioses were established over a four-week period. Mycorrhizal development, pathogen infection sites and development in mycorrhizal plants and non-mycorrhizal control plants were assessed microscopically. The root-colonising intensity of the tested ERMF differed considerably, but each of the applied ERMF impaired external pathogen mycelium and reduced pathogenic infections. A complete reduction was achieved at higher ERMF colonisation levels. The failure of symbiosis formation allowed pathogens to infect and spread. The quantification data concerning mycorrhiza frequencies and extramatrical hyphal nets provided details for a discussion on the suppressive effects of ERMF on the pathogens. The tested ERMF confer at least a localized protection from pathogen attack through suppression prior to infection. It is now to prove, whether these biocontrol effects will also be expressed in pot experiments.

著者

León Ruiz-Herrera María G Hernández-Equihua Daniel Boone-Villa Gema C. Manuel Jacobo Asdrubal Aguilera-Méndez

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.13, pp.29-40, 2019 (Released:2020-02-14)

参考文献数

51

被引用文献数

2

---

Biotin is a member of the vitamin B-complex family that acts as a cofactor of carboxylases and is essential in the metabolism of all organisms. In addition to its essential metabolic functions, biotin has been suggested to play a critical role in regulating gene expression in plants and animals. However, all studies in plants have been conducted under biotin deficiency. Therefore, we hypothesized that exogenously supplied biotin also exerts non-enzymological functions similar to those reported in animals, regulating root growth and development in Arabidopsis thaliana. To test this hypothesis, we evaluated the effects of the biotin supply on seedlings and analyzed the root architecture. Biotin supplementation inhibited root elongation and promoted lateral root formation in a concentration-dependent manner. Inhibited primary root elongation was correlated with decreased expression of the cell cycle genes CycB1;1:uidA and cell expansion gene pAtExp7::uidA, and depended on the concentration of biotin. Viability tests with AtHisH2B:YFP showed that the meristem was depleted. However, biotin supplementation did not affect the concentration of chlorophyll but had a slight inhibitory effect on foliage growth and increased the production of reactive oxygen species (ROS) at the apex of primary roots. Our study provides the first evidence of functions of biotin supplementation in plants in addition to its catalytic role as an enzyme cofactor, likely advancing our understanding of the biological functions of biotin.

著者

小宮山 鉄兵 安 東赫 新妻 成一 矢作 学

出版者

Japanese Society for Root Research

雑誌

根の研究 = Root research (ISSN:09192182)

巻号頁・発行日

vol.21, no.4, pp.113-118, 2012-12-20

---

養液土耕栽培では根が灌水施肥部に集中する特徴があり,根の発達と関連性がある養分の吸収が慣行栽培と異なることが想定された.本研究ではトマトの養液土耕栽培における窒素肥料の種類が施肥もしくは土壌に蓄積された養分の吸収に及ぼす影響について明らかにした.硝酸カルシウムを灌水施肥した場合,リン酸無施用条件で減収した.一方,硝酸アンモニウムを灌水施肥した場合はリン酸無施用でも減収しなかった.これは硝酸イオンがリン酸の吸収を抑制している可能性を示唆し,リン酸の肥沃度が低い条件においては硝酸アンモニウムの施用が土壌リン酸の吸収を促進することが示唆された.また,養液土耕栽培によってアンモニウムイオンを局所的に施用することにより,土壌に保持されたカルシウムイオン,マグネシウムイオンが土壌溶液中に置換され,トマトによる吸収量が高まった.一方,有機質肥料の施用はカルシウム,マグネシウムの吸収量を低下させたが,尻腐れなどの生理障害はみられなかった.以上の結果から硝酸アンモニウムを用いた養液土耕栽培では全層施肥栽培や他の窒素肥料を用いた養液土耕栽培と比較してリン酸,カルシウム,およびマグネシウムなどの吸収が促進されると考えられた.処理区によって根量は異なったが,リン酸吸収量と正の相関はみられなかった.

著者

岡田 浩明

出版者

Japanese Society for Root Research

雑誌

根の研究 (ISSN:09192182)

巻号頁・発行日

vol.11, no.1, pp.3-6, 2002-03-20 (Released:2009-12-18)

参考文献数

9

被引用文献数

7 5

---

土壌に生息する線虫は, その食性に基づいて5グループ程度に分けられる. そのうち, 物質循環との関わりが強い, 細菌食性線虫と糸状菌食性線虫が, 有機物の分解で生じる無機態窒素の生成量におよぼす影響を調べた実験を紹介した. 細菌食性線虫の実験では, 土壌温度や有機物のC/N比によらず, 線虫を入れた試験区の方が入れない区より無機態窒素の生成量が増えた. 糸状菌食性線虫の実験では, 有機物のC/N比の増加に伴い, 線虫を入れない試験区では無機態窒素の生成量が減少したが, 線虫を入れた区では減少しなかった. また, 糸状菌食性線虫を入れた試験区では, 線虫の増殖適温の下で窒素の生成量が最大になった.

著者

Yasuhiro Hirano Kyotaro Noguchi Mizue Ohashi Takuo Hishi Naoki Makita Saori Fujii Leena Finér

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.3, pp.26-31, 2009 (Released:2009-12-15)

参考文献数

13

被引用文献数

23 24

---

We describe a new and easy technique for placing and lifting root meshes to estimate fine root production in forest ecosystems. The method improves upon previously proposed mesh placement techniques by using a sharp stainless steel blade and two thin stainless steel sheets to insert mesh more easily and accurately in the soil, and utilizing a narrow garden spade to lift the soil block containing the mesh. The proposed technique takes significantly less time than the widely used ingrowth core method, causes minimal disturbance to the soil, and requires only simple equipment. The detailed documentation of the method provided herein should improve estimations of fine root production in forest ecosystems.

著者

中村 好男

出版者

Japanese Society for Root Research

雑誌

根の研究 (ISSN:09192182)

巻号頁・発行日

vol.10, no.4, pp.127-133, 2001-12-21 (Released:2009-12-18)

参考文献数

31

---

根はミミズの生態を調査研究するのに, まことにやっかいな物. 同様にミミズは根の形態や機能を調査研究する場合に, やっかいで, 実験やモデル化にはむしろ存在しないほうが都合が良いようでもある. しかし現実には, 根の生育環境としてミミズは存在する. しかもミミズを移入し栽培した大麦は草丈が伸び, 茎や子実のカルシウム含量や収量が増加した. 移入するミミズ数が増すと, その変化は加速された. この地上部の変化は地下部の変化に対応した結果である. 著者はこの地下部を3機能 (生産・分解・調整) を有する土壌圏としてとらえる必要性, 及びミミズはこれら3機能を正常に, かつ永続的に働くための主要な動物であることを強調したい.

著者

矢野 勝也

出版者

Japanese Society for Root Research

雑誌

根の研究 (ISSN:09192182)

巻号頁・発行日

vol.15, no.1, pp.11-17, 2006-03-24 (Released:2009-12-18)

参考文献数

20

被引用文献数

4 4

---

陸上植物の根は, むき出しの「根」で存在するよりも, 共生微生物の菌根菌が共生した状態の「菌根」で存在しているのが普通である. 最も普遍的にみられるのがVA菌根であり, この菌根が形成されると宿主植物のリン獲得能が向上することはよく知られている. しかし, 多くの生態系で植物の成長を律速しているのはリンよりもむしろ窒素であるが, VA菌根菌が宿主植物の窒素栄養に関与しているかどうかは議論が続いてきた. 私たちは最近, アンモニアを吸収したVA菌根菌は速やかに宿主にその窒素を提供するのに, 硝酸を吸収した場合には自らが利用するだけで宿主に受け渡さない, という選択的な窒素供給現象を見いだした. 本稿では, VA菌根菌が宿主植物の窒素栄養にどのように関与するのかについて, 私たちの研究を紹介しつつ, 過去の研究の問題点について議論する.

著者

サウジアラビア海洋性沙漠開発プロジェクト緑化・生物

出版者

Japanese Society for Root Research

雑誌

根の研究 (ISSN:09192182)

巻号頁・発行日

vol.16, no.1, pp.13-16, 2007-03-26 (Released:2009-12-18)

参考文献数

4

著者

Arata Tarui Atsushi Matsumura Sohei Asakura Kenji Yamawaki Rintaro Hattori Hiroyuki Daimon

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.7, pp.83-91, 2013 (Released:2013-12-24)

参考文献数

30

被引用文献数

4 4

---

Legume-grass mixed cropping has significant advantages that affect crop yield and soil resources. Generally, grasses grown with legumes take up more nitrogen than those grown under sole cropping. We focused on the effect of cutting hairy vetch during a vigorous growth stage on N uptake in oat under mixed cropping. We evaluated the amounts of N transferred from hairy vetch to oat by using a 15N dilution method. Cutting hairy vetch increased the number of tillers and dry weight of oat, but total N content was not significantly higher than that under mixed cropping without cutting. In contrast, the amount of N transferred to oat was increased by cutting. Estimated amounts of N transferred to oat were 2.7 g m-2 with cutting of hairy vetch and 0.8 g m-2 without cutting. Cutting half of the oats under sole cropping did not indicate the transfer of rhizodeposited N in oat to the residual plants. In addition, cutting hairy vetch increased the amounts of accumulated solar radiation in the middle canopy of the mixed cropping plots. Therefore, in a hairy vetch and oat mixed cropping system, cutting of the hairy vetch might enhance growth of oat due to the transfer of N from hairy vetch and the reduction of light interception to the oat canopy. N fertility enhancement of the soil by cutting of the legume would be valuable for low-input crop production.

著者

Emdadul Haque Eiji Yamamoto Kenta Shirasawa Hiroaki Tabuchi Ung-Han Yoon Sachiko Isobe Masaru Tanaka

出版者

Japanese Society for Root Research

雑誌

Plant Root (ISSN:18816754)

巻号頁・発行日

vol.14, pp.11-21, 2020 (Released:2020-10-09)

参考文献数

31

被引用文献数

6

---

Genetic studies on the purple-fleshed sweetpotato (Ipomoea batatas L.), which is rich in anthocyanin (AN) in the storage root, were performed by polyploid GWAS based on the allele dosage probability using 59,675 SNPs obtained from 94 F1 progenies between the cultivars 'Konaishin' (which has a high yield but no AN) and 'Akemurasaki' (which has a high AN content but low to moderate yield). The distribution of relative AN content was highly biased, with 60% of clones showing a low to undetectable level (A530 < 0.5). Fifty-nine SNPs from six signals on homologous groups (HGs) 3, 5 (one major and one smaller signal), 7, 13, and 15 were strongly associated with the relative AN content. Twelve SNPs from the major signal and one from the smaller signal of HG 5 were further detected by QTL analysis. In a database search of the AN biosynthesis gene, transcription factors IbMYB1 and IbWD40 and AN structural genes IbF3H and IbDFR were located on HG 5, suggesting that an SNP marker or markers from HG 5 might be tightly linked to candidate gene(s) homologous to one of these transcription factors and AN structural genes as a major factor in determining AN accumulation in the storage roots. These results would enhance our understanding of the underlying genetic basis of AN accumulation in the storage roots of sweetpotatoes, and the SNP markers found here, especially 13 SNPs from HG 5, would be a potential platform for future marker-assisted selection for breeding high-AN sweetpotato varieties.

著者

里村 多香美 橋本 靖 木下 晃彦 堀越 孝雄

出版者

Japanese Society for Root Research

雑誌

根の研究 = Root research (ISSN:09192182)

巻号頁・発行日

vol.15, no.4, pp.155-159, 2006-12-29

参考文献数

23

---

生態系の炭素循環における菌類の役割の重要性が認識されているにも関わらず, 野外条件下で菌根菌に分配される炭素量の推定値は数えるほどしか報告されていない。生態系の炭素循環における菌類の役割について定量的な値を用いて議論するため, アカマツ林で外生菌根菌に分配される炭素量を概推した。直接得られなかった土壌中の外生菌根菌バイオマス, 細根 (菌根を含む) と外生菌根菌のターンオーバーの値は, 文献値を参照した。その結果, アカマツ林の外生菌根菌のバイオマスの総量はわずか10.0gm^-2であると推定され, 細根のバイオマスが少ないことが大きく影響していると考えられた。この林分では菌根菌の生成と枯死サイクルによって年間に消費される炭素は117.0gCm^-2year^-1と推定され, 土壌からの炭素の放出の約24%に相当した。アカマツ林は細根のバイオマス, 細根中の菌類含有量, 外生菌根菌のバイオマスが共に文献値よりも非常に低いという特徴があった。森林タイプ間の外生菌根菌のバイオマスの違いに大きく影響を及ぼしているのは, 細根中の菌類含有量の差異よりも細根のバイオマスの差異であった。外生菌根菌のバイオマスが小さい森林においても, 菌根菌の生成・枯死サイクルによって消費される炭素量は無視できないことが改めて確認された。