Photosynthetic plasticity of young plants of Carpotroche brasiliensis (Raddi) A. Gray, Achariaceae

Autor: Carlos Alberto da Silva Ledo, Ândrea Carla Dalmolin, Delmira da Costa Silva, Marcelo Schramm Mielke, Amanda Freitas Cerqueira, Letícia dos Anjos
Rok vydání: 2017
Předmět:
Zdroj: Trees. 32:191-202
ISSN: 1432-2285
0931-1890
DOI: 10.1007/s00468-017-1623-6
Popis: We analyzed the shade tolerance of a tropical tree species based on the plasticity of 22 photosynthetic traits. Carpotroche brasiliensis leaves have characteristics of a shade-tolerant species, with low photosynthetic plasticity. The objective of this study was to evaluate the photosynthetic plasticity of young Carpotroche brasiliensis plants in response to different light environments. This tropical tree species has some shade-tolerant traits, such as large and fleshy fruits, seeds with a high water content, and the ability for natural regeneration in the forest understory. In this way, we tested the hypothesis that, at the leaf scale, young C. brasiliensis plants have photosynthetic characteristics of shade-tolerant species, with low photosynthetic plasticity when grown under different light environments. For this, seedlings were subjected to four light treatments (60, 35, 25, and 15% full sunlight, corresponding to about 20.9, 11.9, 9.1, and 5.4 mol photons m−2 day−1, respectively) for 5 months. We evaluated the photosynthetic plasticity at the leaf scale through morphological and anatomical variables, as well as variables associated with the diffusive, photochemical, and biochemistry phases of photosynthesis. All key photosynthetic variables measured exhibited values of typical shaded leaves. The highest simplified relative distance plasticity index (RDPI) for light treatments was found for light compensation point (0.32), performance index (0.30), photochemical reflectance index (0.30), mesophyll conductance (0.27), dark respiration rate (0.27), and leaf area (0.19). The lowest RDPI for light treatments was found for the leaf anatomical variables (
Databáze: OpenAIRE
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