Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes

The physiological and anatomical adaptability of pastures growing under trees in silvopastoral systems can alter the efficiency of conversion of energy to dry matter (DM). This study was conducted to determine the effects of different fluctuating light regimes (from 24 to 100% transmissivity) on lea...

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Autores principales: Peri, Pablo Luis, Moot, Derrick, Jarvis, Peter, McNeil, David L., Lucas, R.J.
Formato: Artículo
Lenguaje:Inglés
Publicado: Wiley 2025
Materias:
Acceso en línea:http://hdl.handle.net/20.500.12123/23887
https://acsess.onlinelibrary.wiley.com/doi/10.2134/agronj2006.0347
https://doi.org/10.2134/agronj2006.0347
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author Peri, Pablo Luis
Moot, Derrick
Jarvis, Peter
McNeil, David L.
Lucas, R.J.
author_browse Jarvis, Peter
Lucas, R.J.
McNeil, David L.
Moot, Derrick
Peri, Pablo Luis
author_facet Peri, Pablo Luis
Moot, Derrick
Jarvis, Peter
McNeil, David L.
Lucas, R.J.
author_sort Peri, Pablo Luis
collection INTA Digital
description The physiological and anatomical adaptability of pastures growing under trees in silvopastoral systems can alter the efficiency of conversion of energy to dry matter (DM). This study was conducted to determine the effects of different fluctuating light regimes (from 24 to 100% transmissivity) on leaf physiology, morphology, anatomy, and structure of orchardgrass (Dactylis glomerata L.) in a silvopastoral experiment (New Zealand). Slatted shade structures created a bimodal light regime that represented an existing silvopastoral system. Morphologically, as transmissivity decreased the length of the youngest fully expanded leaf and pseudo-stem height increased by up to 33% and the leaf width declined up to 22%. Physiologically, leaf adaptation to different light regimes was characterized by: (i) the light-saturated rate of net photosynthesis (Pmax) and to less extent the photosynthetic efficiency (a) in sun conditions was double; (ii) in sunny conditions plants grown under shade were photosynthetically less efficient than plants grown in full sunlight with lower Pmax and a values; (iii) when plants were exposed to severe shade, leaves adapted to severe shade condition had the highest Pmax, a, and u, and saturated at the minimum photosynthetic photon flux density (PPFD) value. These changes in leaf photosynthesis characteristics under different light regimes were attributed to anatomical changes that caused reductions in stomatal conductance (gs), the mesophyll surface area/leaf surface area ratio (Ames/A) and maintenance respiration for shade adapted plants. These photosynthetic responses and leaf adaptations to fluctuating light regimes can be included into a canopy photosynthesis model to improve the accuracy of DM predictions in silvopastoral systems.
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spelling INTA238872025-09-22T13:14:18Z Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes Peri, Pablo Luis Moot, Derrick Jarvis, Peter McNeil, David L. Lucas, R.J. Pastures Silvopastoral Systems Dry Matter Physiology Morphology Anatomy Photosynthesis Pastizales Sistemas Silvopascícolas Materia Seca Fisiología Morfología Anatomía Dactylis glomerata Fotosíntesis Sistemas Silvopastoriles Régimen fluctuantes de luz Trasmisibidad Fotosíntesis Neta Eficiencia Fotosintética Fluctuating Light Regimes Transmissivity Net Photosynthesis Photosynthetic Efficiency Pasto Ovillo The physiological and anatomical adaptability of pastures growing under trees in silvopastoral systems can alter the efficiency of conversion of energy to dry matter (DM). This study was conducted to determine the effects of different fluctuating light regimes (from 24 to 100% transmissivity) on leaf physiology, morphology, anatomy, and structure of orchardgrass (Dactylis glomerata L.) in a silvopastoral experiment (New Zealand). Slatted shade structures created a bimodal light regime that represented an existing silvopastoral system. Morphologically, as transmissivity decreased the length of the youngest fully expanded leaf and pseudo-stem height increased by up to 33% and the leaf width declined up to 22%. Physiologically, leaf adaptation to different light regimes was characterized by: (i) the light-saturated rate of net photosynthesis (Pmax) and to less extent the photosynthetic efficiency (a) in sun conditions was double; (ii) in sunny conditions plants grown under shade were photosynthetically less efficient than plants grown in full sunlight with lower Pmax and a values; (iii) when plants were exposed to severe shade, leaves adapted to severe shade condition had the highest Pmax, a, and u, and saturated at the minimum photosynthetic photon flux density (PPFD) value. These changes in leaf photosynthesis characteristics under different light regimes were attributed to anatomical changes that caused reductions in stomatal conductance (gs), the mesophyll surface area/leaf surface area ratio (Ames/A) and maintenance respiration for shade adapted plants. These photosynthetic responses and leaf adaptations to fluctuating light regimes can be included into a canopy photosynthesis model to improve the accuracy of DM predictions in silvopastoral systems. EEA Santa Cruz Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina. Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Moot, Derrick. Lincoln University. Faculty of Agriculture an Life Science; Nueva Zelandia. Fil: Jarvis, Peter. Lincoln University. Faculty of Agriculture an Life Science; Nueva Zelandia. Fil: McNeil, David L. Lincoln University. Faculty of Agriculture an Life Science; Nueva Zelandia. Fil: Lucas, R. J. Lincoln University. Faculty of Agriculture and Life Science; Nueva Zelandia. 2025-09-22T13:08:19Z 2025-09-22T13:08:19Z 2007-11 info:ar-repo/semantics/artículo info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/20.500.12123/23887 https://acsess.onlinelibrary.wiley.com/doi/10.2134/agronj2006.0347 Peri P.L.; Moot D.J.; Jarvis P.; Mcneil D.L.; Lucas R.J. (2007) Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes. Agronomy Journal 99: 1502-1513. 1435-0645 (Online) 0002-1962 (Print) https://doi.org/10.2134/agronj2006.0347 eng info:eu-repo/semantics/restrictedAccess http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf Wiley Agronomy Journal 99 (6) : 1502-1513. (November 2007)
spellingShingle Pastures
Silvopastoral Systems
Dry Matter
Physiology
Morphology
Anatomy
Photosynthesis
Pastizales
Sistemas Silvopascícolas
Materia Seca
Fisiología
Morfología
Anatomía
Dactylis glomerata
Fotosíntesis
Sistemas Silvopastoriles
Régimen fluctuantes de luz
Trasmisibidad
Fotosíntesis Neta
Eficiencia Fotosintética
Fluctuating Light Regimes
Transmissivity
Net Photosynthesis
Photosynthetic Efficiency
Pasto Ovillo
Peri, Pablo Luis
Moot, Derrick
Jarvis, Peter
McNeil, David L.
Lucas, R.J.
Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title_full Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title_fullStr Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title_full_unstemmed Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title_short Morphological, anatomical, and physiological changes of orchardgrass leaves grown under fluctuating light regimes
title_sort morphological anatomical and physiological changes of orchardgrass leaves grown under fluctuating light regimes
topic Pastures
Silvopastoral Systems
Dry Matter
Physiology
Morphology
Anatomy
Photosynthesis
Pastizales
Sistemas Silvopascícolas
Materia Seca
Fisiología
Morfología
Anatomía
Dactylis glomerata
Fotosíntesis
Sistemas Silvopastoriles
Régimen fluctuantes de luz
Trasmisibidad
Fotosíntesis Neta
Eficiencia Fotosintética
Fluctuating Light Regimes
Transmissivity
Net Photosynthesis
Photosynthetic Efficiency
Pasto Ovillo
url http://hdl.handle.net/20.500.12123/23887
https://acsess.onlinelibrary.wiley.com/doi/10.2134/agronj2006.0347
https://doi.org/10.2134/agronj2006.0347
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