Plasticity of Morphology in Subterranean Stems in Long and Short Day in the Lotus (Nelumbo nucifera)

Jun-ichiro Masuda, Yukio Ozaki, Michikazu Hiramatsu, Kaori Sakai, Junghee Kim, Hiroshi Okubo

研究成果: ジャーナルへの寄稿記事

抄録

<p>Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.</p>
元の言語英語
ジャーナルHorticulture Journal
DOI
出版物ステータス出版済み - 2018

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Nelumbo nucifera
Lotus
rhizomes
photoperiod
dormancy
stems
internodes
temperature
seedlings
environmental factors
stem elongation
morphogenesis
Japan
greenhouses

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Plasticity of Morphology in Subterranean Stems in Long and Short Day in the Lotus (Nelumbo nucifera). / Masuda, Jun-ichiro; Ozaki, Yukio; Hiramatsu, Michikazu; Sakai, Kaori; Kim, Junghee; Okubo, Hiroshi.

:: Horticulture Journal, 2018.

研究成果: ジャーナルへの寄稿記事

@article{a11dcfd666f147a49c8d63f8f4a759b6,
title = "Plasticity of Morphology in Subterranean Stems in Long and Short Day in the Lotus (Nelumbo nucifera)",
abstract = "Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.",
author = "Jun-ichiro Masuda and Yukio Ozaki and Michikazu Hiramatsu and Kaori Sakai and Junghee Kim and Hiroshi Okubo",
year = "2018",
doi = "10.2503/hortj.OKD-082",
language = "English",
journal = "Horticulture Journal",
issn = "2189-0102",
publisher = "THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE",

}

TY - JOUR

T1 - Plasticity of Morphology in Subterranean Stems in Long and Short Day in the Lotus (Nelumbo nucifera)

AU - Masuda, Jun-ichiro

AU - Ozaki, Yukio

AU - Hiramatsu, Michikazu

AU - Sakai, Kaori

AU - Kim, Junghee

AU - Okubo, Hiroshi

PY - 2018

Y1 - 2018

N2 - Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.

AB - Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.

U2 - 10.2503/hortj.OKD-082

DO - 10.2503/hortj.OKD-082

M3 - Article

JO - Horticulture Journal

JF - Horticulture Journal

SN - 2189-0102

ER -