Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory
Ocean warming and the associated changes in fish herbivory have caused polarward distributional shifts in the majority of canopy-forming macroalgae that are dominant in temperate Japan, but have little effect on the alga <i>Sargassum fusiforme</i>. The regeneration ability of new shoots...
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MDPI AG
2021-07-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/10/8/1522 |
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| author | Hikaru Endo Toru Sugie Yukiko Yonemori Yuki Nishikido Hikari Moriyama Ryusei Ito Suguru Okunishi |
| author_facet | Hikaru Endo Toru Sugie Yukiko Yonemori Yuki Nishikido Hikari Moriyama Ryusei Ito Suguru Okunishi |
| author_sort | Hikaru Endo |
| collection | DOAJ |
| description | Ocean warming and the associated changes in fish herbivory have caused polarward distributional shifts in the majority of canopy-forming macroalgae that are dominant in temperate Japan, but have little effect on the alga <i>Sargassum fusiforme</i>. The regeneration ability of new shoots from holdfasts in this species may be advantageous in highly grazed environments. However, little is known about the factors regulating this in <i>Sargassum</i> species. Moreover, holdfast tolerance to high-temperature and nutrient-poor conditions during summer has rarely been evaluated. In the present study, <i>S. fusiforme</i> holdfast responses to the combined effects of temperature and nutrient availability were compared to those of sexually reproduced propagules. The combined effects of holdfast fragmentation and irradiance on regeneration were also evaluated. Propagule growth rate values changed from positive to negative under the combination of elevated temperature (20 °C–30 °C) and reduced nutrient availability, whereas holdfasts exhibited a positive growth rate even at 32 °C in nutrient-poor conditions. The regeneration rate increased with holdfast fragmentation (1 mm segments), but was unaffected by decreased irradiance. These results suggest that <i>S. fusiforme</i> holdfasts have a higher tolerance to high-temperature and nutrient-poor conditions during summer than propagules, and regenerate new shoots even if 1-mm segments remain in shaded refuges for fish herbivory avoidance. |
| first_indexed | 2024-03-10T08:28:35Z |
| format | Article |
| id | doaj.art-aa1f2d779f7c4f80b0112b9a50a01881 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-10T08:28:35Z |
| publishDate | 2021-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-aa1f2d779f7c4f80b0112b9a50a018812023-11-22T09:17:32ZengMDPI AGPlants2223-77472021-07-01108152210.3390/plants10081522Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive HerbivoryHikaru Endo0Toru Sugie1Yukiko Yonemori2Yuki Nishikido3Hikari Moriyama4Ryusei Ito5Suguru Okunishi6Faculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanFaculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanFaculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanFaculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanFaculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanFisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Bungotakada 879-0608, JapanFaculty of Fisheries, Kagoshima University, Kagoshima 890-0056, JapanOcean warming and the associated changes in fish herbivory have caused polarward distributional shifts in the majority of canopy-forming macroalgae that are dominant in temperate Japan, but have little effect on the alga <i>Sargassum fusiforme</i>. The regeneration ability of new shoots from holdfasts in this species may be advantageous in highly grazed environments. However, little is known about the factors regulating this in <i>Sargassum</i> species. Moreover, holdfast tolerance to high-temperature and nutrient-poor conditions during summer has rarely been evaluated. In the present study, <i>S. fusiforme</i> holdfast responses to the combined effects of temperature and nutrient availability were compared to those of sexually reproduced propagules. The combined effects of holdfast fragmentation and irradiance on regeneration were also evaluated. Propagule growth rate values changed from positive to negative under the combination of elevated temperature (20 °C–30 °C) and reduced nutrient availability, whereas holdfasts exhibited a positive growth rate even at 32 °C in nutrient-poor conditions. The regeneration rate increased with holdfast fragmentation (1 mm segments), but was unaffected by decreased irradiance. These results suggest that <i>S. fusiforme</i> holdfasts have a higher tolerance to high-temperature and nutrient-poor conditions during summer than propagules, and regenerate new shoots even if 1-mm segments remain in shaded refuges for fish herbivory avoidance.https://www.mdpi.com/2223-7747/10/8/1522climate changefoundation speciesfucoid brown algaenon-additive effectsimulated herbivory |
| spellingShingle | Hikaru Endo Toru Sugie Yukiko Yonemori Yuki Nishikido Hikari Moriyama Ryusei Ito Suguru Okunishi Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory Plants climate change foundation species fucoid brown algae non-additive effect simulated herbivory |
| title | Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory |
| title_full | Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory |
| title_fullStr | Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory |
| title_full_unstemmed | Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory |
| title_short | Vegetative Reproduction Is More Advantageous Than Sexual Reproduction in a Canopy-Forming Clonal Macroalga under Ocean Warming Accompanied by Oligotrophication and Intensive Herbivory |
| title_sort | vegetative reproduction is more advantageous than sexual reproduction in a canopy forming clonal macroalga under ocean warming accompanied by oligotrophication and intensive herbivory |
| topic | climate change foundation species fucoid brown algae non-additive effect simulated herbivory |
| url | https://www.mdpi.com/2223-7747/10/8/1522 |
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