Photosynthetic traits of five neotropical rainforest tree species: interactions between light response curves and leaf-to-air vapour pressure deficit

Mielke, Marcelo Schramm; Almeida, Alex-Alan Furtado de; Gomes, Fábio Pinto

doi:10.1590/s1516-89132005000600018

Cited by 21 publications

(14 citation statements)

References 31 publications

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“…The plants were subjected to radiations of 1200, 1000, 800, 600, 400, 300, 200, 100, 50 and 0 μmol photons/m 2 s consecutively and the leaves in each radiation level were left to stabilize for a minimum of three minutes. The curves were adjusted by regression to a rectangular hyperbolic model (Mielke et al, 2005;Solarte et al, 2010) of the equation:…”

Section: Photosynthetic Light Curvesmentioning

confidence: 99%

PHOTOSYNTHETIC PERFORMANCE AND LEAF WATER POTENTIAL OF GULUPA (Passiflora edulis Sims, PASSIFLORACEAE) IN THE REPRODUCTIVE PHASE IN THREE LOCATIONS IN THE COLOMBIAN ANDES

Martínez¹,

Melgarejo²

2014

Acta biol. colomb.

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Section: Photosynthetic Light Curvesmentioning

confidence: 99%

PHOTOSYNTHETIC PERFORMANCE AND LEAF WATER POTENTIAL OF GULUPA (Passiflora edulis Sims, PASSIFLORACEAE) IN THE REPRODUCTIVE PHASE IN THREE LOCATIONS IN THE COLOMBIAN ANDES

Martínez¹,

Melgarejo²

2014

Acta biol. colomb.

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“…The cacao leaf is saturated at low irradiance and shows low A (4 µmol CO 2 m -2 s -1 ) at water vapor deficits between leaf and air of 1.8 kPa (Mielke et al, 2005).…”

Section: Effects Of Abiotic Factors On Yieldmentioning

confidence: 99%

Ecophysiology of the cacao tree

Almeida

Valle

2007

Braz. J. Plant Physiol.

203

129

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Cacao, one of the world's most important perennial crops, is almost exclusively explored for chocolate manufacturing. Most cacao varieties belong to three groups: Criollo, Forastero and Trinitario that vary according to morphology, genetic and geographical origins. It is cropped under the shade of forest trees or as a monocrop without shade. Seedlings initially show an orthotropic growth with leaf emission relatively independent of climate. The maturity phase begins with the emission of plagiotropic branches that form the tree crown. At this stage environmental factors exert a large influence on plant development. Growth and development of cacao are highly dependent on temperature, which mainly affects vegetative growth, flowering and fruit development. Soil flooding decreases leaf area, stomatal conductance and photosynthetic rates in addition to inducing formation of lenticels and adventitious roots. For most genotypes drought resistance is associated with osmotic adjustment. Cacao produces caulescent flowers, which begin dehiscing in late afternoon and are completely open at the beginning of the following morning releasing pollen to a receptive stigma. Non pollinated flowers abscise 24-36 h after anthesis. The percentage of flowers setting pods is in the range 0.5 -5%. The most important parameters determinants of yield are related to: (i) light interception, photosynthesis and capacity of photoassimilate distribution, (ii) maintenance respiration and (iii) pod morphology and seed fermentation, events that can be modified by abiotic factors. Cacao is a shade tolerant species, in which appropriate shading leads to relatively high photosynthetic rates, growth and seed yield. However, heavy shade reduces seed yield and increases incidence of diseases; in fact, cacao yields and light interception are tightly related when nutrient availability is not limiting. High production of non-shaded cacao requires high inputs in protection and nutrition of the crop. Annual radiation and rainfall during the dry season explains 70% of the variations in annual seed yields. Key words: root growth, flowering, pod set, flushing, mineral nutrition Ecofisiologia do cacaueiro: O cacau, um dos mais importantes cultivos perenes no mundo, é quase exclusivamente explorado para a fabricação de chocolate. A maioria das variedades de cacau pertence a três grupos: Criollo, Forasteiro e Trinitário, que variam de acordo com a morfologia, genética e origem geográfica. É cultivado sob sombra de árvores de floresta ou como monocultivo sem sombra. As plântulas inicialmente mostram um crescimento ortotrópico com emissão de folhas relativamente independente do clima. A fase de maturidade inicia-se com a emissão de ramos plagiotrópicos que formam a copa. Nesse estádio, fatores ambientes exercem grande influência no desenvolvimento da planta. O crescimento e o desenvolvimento do cacaueiro são dependentes da temperatura, que afeta principalmente o crescimento vegetativo, florescimento e desenvolvimento do fruto. O alagamento do solo diminui a área fol...

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“…As such, the photosynthetic characteristics of cacao are those of a shade-adapted species with a low light compensation point and leaf photosynthesis that is usually light saturated at low irradiance, typically around 20 % of full sunlight (Hutcheon 1977, Raja Harun and Hardwick 1988a, Mielke et al 2005. Light saturated photosynthetic rates in cacao have been recorded in the region of 2 -8 µmol(CO 2 ) m -2 s -1 (e.g.…”

Section: Introductionmentioning

confidence: 99%

Genotypic variation in photosynthesis in cacao is correlated with stomatal conductance and leaf nitrogen

Daymond¹,

Tricker²,

Hadley³

2011

Biol. plant.

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Traits such as transpiration efficiency (TE) that are influenced by plant water use can be used to characterise the adaptability of crops to specific growth environments. TE is defined as the amount of biomass produced per unit of water used, and can ensure continued crop production in drought-prone regions. Where TE is associated with reduced use of soil water during the vegetative growth phase, water availability during grain filling may be greater, which can delay the onset of drought stress and increase grain yield under water-limited conditions. This may become even more pertinent with predicted increases in severity and frequency of droughts with climate change. The aims of this study were to firstly dissect TE into its leaf-level physiological components to better understand the effects of genetic variation in these components on TE in sorghum. Secondly, to examine whether TE responses observed under well-watered conditions were preserved under drought, and whether transpiration response was an adaptive response to drought. Twenty-seven genotypes were screened for TE under well-watered conditions using a fully automated lysimetry platform to obtain accurate plant water use data. To determine whether variation in TE among these genotypes was associated with differences in maximum photosynthesis (Amax) or leaf conductance (g) we measured the net carbon assimilation rate of the second last fully expanded leaf at high light intensity, using an infrared gas analyser, and leaf water flux was measured using a porometer, as a proxy for conductance. Genotypic variation in TE among the sorghum germplasm used was mainly associated with differences in the response of transpiration rates to vapour pressure deficit (VPD). Genotypes with low transpiration rates per unit green leaf area (T/GLA) tended to have high TE. Variation in Amax explained some of the differences in TE that could not be explained by T/GLA and may have been a result of mechanisms associated with differences in biochemical pathways that affect the efficiency of conversion of CO2 into photosynthate. While drought tended to increase TE, genotypic variation in TE was largely conserved. However, the response of transpiration rates to drought stress differed across genotypes, with some genotypes showing reduced T/GLA under drought when VPD was high, whereas others did not. These contrasting responses were associated with differences in stomatal responses to drought stress, such that some genotypes were better able to conserve water under drought stress than others. This adaptive response was not related to TE per se and may have important implications for adaptation to drought stress. Hence, the phenotyping of sorghum lines using the associated physiological traits underpinning TE differences is beneficial in identifying traits that may support growth in certain environments and can optimise grain yield production under water-limited conditions. III

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Photosynthetic traits of five neotropical rainforest tree species: interactions between light response curves and leaf-to-air vapour pressure deficit

Cited by 21 publications

References 31 publications

PHOTOSYNTHETIC PERFORMANCE AND LEAF WATER POTENTIAL OF GULUPA (Passiflora edulis Sims, PASSIFLORACEAE) IN THE REPRODUCTIVE PHASE IN THREE LOCATIONS IN THE COLOMBIAN ANDES

PHOTOSYNTHETIC PERFORMANCE AND LEAF WATER POTENTIAL OF GULUPA (Passiflora edulis Sims, PASSIFLORACEAE) IN THE REPRODUCTIVE PHASE IN THREE LOCATIONS IN THE COLOMBIAN ANDES

Ecophysiology of the cacao tree

Genotypic variation in photosynthesis in cacao is correlated with stomatal conductance and leaf nitrogen

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