HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (2) Citing Articles via Google Scholar Google Scholar Articles by Skillman, J. B. Articles by Winter, K. Search for Related Content PubMed Articles by Skillman, J. B. Articles by Winter, K. Agricola Articles by Skillman, J. B. Articles by Winter, K.

Growth irradiance effects on photosynthesis and growth in two co-occurring shade-tolerant neotropical perennials of contrasting photosynthetic pathways¹

²Department of Biology, California State University, San Bernardino, California 92407 USA; ³Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama

ABSTRACT

Dieffenbachia longispatha (C3) and Aechmea magdalenae (Crassulacean acid metabolism, CAM) are syntopic, neotropical forest perennials in central Panama that are restricted to shaded habitats. This is of particular interest for A. magdalenae because, like other understory CAM bromeliad species, it appears functionally and structurally to be better suited to life in full sun. Growth irradiance (GI) effects on photosynthesis and growth in both species were explored in the context of sun/shade trade-off concepts largely derived from studies of C3 plants. Potted plants were grown outdoors in 1, 55, and 100% full sun for 5 mo under well-watered conditions. While both species grew faster in high compared to low light, maximum relative growth rates (RGR) in full sun were still extremely slow with A. magdalenae showing a RGR approximately half that of D. longispatha. Photosynthetic capacity increased with GI in D. longispatha but not in A. magdalenae. Aechmea magdalenae responded to GI with shifts in the activity of the different CAM phases. Both species were photoinhibited in full sun, but more so in A. magdalenae. Despite possessing many traits considered adaptive in high light, these results suggest that A. magdalenae is unlikely to attain sufficient growth rates to thrive in productive, high-light habitats.

Key Words: Bromeliaceae • chlorophyll fluorescence • Crassulacean acid metabolism • growth analysis • Panama • photoinhibition • photosynthetic acclimation • tropical forest ecology

This article has been cited by other articles:

				J. B. Skillman Quantum yield variation across the three pathways of photosynthesis: not yet out of the dark J. Exp. Bot., May 1, 2008; 59(7): 1647 - 1661. [Abstract] [Full Text] [PDF]

				J. A. M. Holtum, K. Winter, M. A. Weeks, and T. R. Sexton Crassulacean acid metabolism in the ZZ plant, Zamioculcas zamiifolia (Araceae) Am. J. Botany, October 1, 2007; 94(10): 1670 - 1676. [Abstract] [Full Text] [PDF]

				O. Hernandez-Gonzalez and O. B. Villarreal Crassulacean acid metabolism photosynthesis in columnar cactus seedlings during ontogeny: the effect of light on nocturnal acidity accumulation and chlorophyll fluorescence Am. J. Botany, August 1, 2007; 94(8): 1344 - 1351. [Abstract] [Full Text] [PDF]