Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L.
Many biotypes of the northern‐hemisphere Arctic‐Alpine grass Poa alpina L. reproduce asexually via prolification of the spikelet axis to produce dehiscing shoots. Although capable of photosynthesis, the source–sink characteristics of these synflorescence systems are unknown, including the degree to...
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2000
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fthighwire:oai:open-archive.highwire.org:jexbot:51/351/1705 2023-05-15T15:07:10+02:00 Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. Pierce, S. Stirling, C.M. Baxter, R. 2000-10-01 00:00:00.0 text/html http://jxb.oxfordjournals.org/cgi/content/short/51/351/1705 https://doi.org/10.1093/jexbot/51.351.1705 en eng Oxford University Press http://jxb.oxfordjournals.org/cgi/content/short/51/351/1705 http://dx.doi.org/10.1093/jexbot/51.351.1705 Copyright (C) 2000, Society for Experimental Biology Regulation of Growth Development and Whole Organism Physiology TEXT 2000 fthighwire https://doi.org/10.1093/jexbot/51.351.1705 2015-02-28T18:56:19Z Many biotypes of the northern‐hemisphere Arctic‐Alpine grass Poa alpina L. reproduce asexually via prolification of the spikelet axis to produce dehiscing shoots. Although capable of photosynthesis, the source–sink characteristics of these synflorescence systems are unknown, including the degree to which plantlets from different regions of the synflorescence are capable of providing for their own carbon requirements, or contributing to other sinks. Photosynthetic rates within the paracladial zone, as determined by infrared gas analysis (IRGA), exceeded respiratory rates by 3–4‐fold. 14CO 2 tracer studies determined that the paracladial zone was not only as efficient at fixing carbon as the youngest fully expanded leaf (per unit dry weight), but that both organs exported carbon mainly basipetally (cf. extensive acropetal export from this leaf in seminiferous grasses). Distal plantlets of the paracladial zone fixed approximately 20% more 14CO 2 than did proximal plantlets. This was by virtue of their greater dry weight. At dehiscence, ‘distal’ plantlets were more likely to become established, and possessed relative growth rates more than 10 times those of ‘proximal’ plantlets. Paracladial heterogeneity was also apparent as an increased proportion of aborted spikelets on proximal paracladia. The possible causes of this heterogeneity are discussed. Text Arctic Poa alpina HighWire Press (Stanford University) Arctic Journal of Experimental Botany 51 351 1705 1712 |
institution |
Open Polar |
collection |
HighWire Press (Stanford University) |
op_collection_id |
fthighwire |
language |
English |
topic |
Regulation of Growth Development and Whole Organism Physiology |
spellingShingle |
Regulation of Growth Development and Whole Organism Physiology Pierce, S. Stirling, C.M. Baxter, R. Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
topic_facet |
Regulation of Growth Development and Whole Organism Physiology |
description |
Many biotypes of the northern‐hemisphere Arctic‐Alpine grass Poa alpina L. reproduce asexually via prolification of the spikelet axis to produce dehiscing shoots. Although capable of photosynthesis, the source–sink characteristics of these synflorescence systems are unknown, including the degree to which plantlets from different regions of the synflorescence are capable of providing for their own carbon requirements, or contributing to other sinks. Photosynthetic rates within the paracladial zone, as determined by infrared gas analysis (IRGA), exceeded respiratory rates by 3–4‐fold. 14CO 2 tracer studies determined that the paracladial zone was not only as efficient at fixing carbon as the youngest fully expanded leaf (per unit dry weight), but that both organs exported carbon mainly basipetally (cf. extensive acropetal export from this leaf in seminiferous grasses). Distal plantlets of the paracladial zone fixed approximately 20% more 14CO 2 than did proximal plantlets. This was by virtue of their greater dry weight. At dehiscence, ‘distal’ plantlets were more likely to become established, and possessed relative growth rates more than 10 times those of ‘proximal’ plantlets. Paracladial heterogeneity was also apparent as an increased proportion of aborted spikelets on proximal paracladia. The possible causes of this heterogeneity are discussed. |
format |
Text |
author |
Pierce, S. Stirling, C.M. Baxter, R. |
author_facet |
Pierce, S. Stirling, C.M. Baxter, R. |
author_sort |
Pierce, S. |
title |
Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
title_short |
Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
title_full |
Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
title_fullStr |
Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
title_full_unstemmed |
Architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass Poa alpina var. vivipara L. |
title_sort |
architectural and physiological heterogeneity within the synflorescence of the pseudoviviparous grass poa alpina var. vivipara l. |
publisher |
Oxford University Press |
publishDate |
2000 |
url |
http://jxb.oxfordjournals.org/cgi/content/short/51/351/1705 https://doi.org/10.1093/jexbot/51.351.1705 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Poa alpina |
genre_facet |
Arctic Poa alpina |
op_relation |
http://jxb.oxfordjournals.org/cgi/content/short/51/351/1705 http://dx.doi.org/10.1093/jexbot/51.351.1705 |
op_rights |
Copyright (C) 2000, Society for Experimental Biology |
op_doi |
https://doi.org/10.1093/jexbot/51.351.1705 |
container_title |
Journal of Experimental Botany |
container_volume |
51 |
container_issue |
351 |
container_start_page |
1705 |
op_container_end_page |
1712 |
_version_ |
1766338726746652672 |