Anatomy and photosynthetic parameters of roots and leaves of two shade-adapted orchids, Dichaea cogniauxiana Shltr. and Epidendrum secundum Jacq.

Moreira, Ana Sílvia Franco Pinheiro; Filho, José Pires de Lemos; Zotz, Gerhard; Isaías, Rosy Mary dos Santos

doi:10.1016/j.flora.2008.08.003

Cited by 30 publications

(22 citation statements)

References 43 publications

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“…Leaf area (LA) was determined through digital analysis of images obtained with an HP scanner at 200 dpi resolution, and processed with the software SIARCS® 3.0 (Integrated System for Roots and Soil Coverage Analysis developed by Embrapa -Agricultural Instrumentation, Brazil). From these data, the following traits were calculated: Root and stem elongation rate (ER, mm day -1 ) and specific leaf mass (DML LA -1 ), leaf succulence from the expression LS = (LFM -LDM) LA -1 (Evans, 1972;Moreira et al, 2009), and stem water content (SWC, %), calculated as: 100* [1-(DMS FMS -1 )]. The results obtained were submitted to variance analysis, treatments being discriminated by test F (P ≤ 0.05), and the means compared by Tukey test (P = 0.05).…”

Section: Methodsmentioning

confidence: 99%

The relationship between succulence and shoot biomass differences according to nutritional status in Jatropha curcas L.

Santos¹,

Silva²,

França³

et al. 2015

Afr. J. Agric. Res.

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Diverse types of studies have examined the application of Jatropha curcas L. as a source of biofuel. Mineral nutrition levels modify the patterns of crops' growth and productivity, as well as the expression of morphophysiological traits of adaptive value. This study investigated the effects of nutrient solution concentration on biomass partition patterns and morphological attributes linked to water content in organs of J. curcas. Selected seedlings of accession 842 were cultivated in full experimental nutritive solution, and in solutions diluted to half concentration and a quarter concentration, all adjusted to pH 6.0. After 28 days under controlled conditions, plants were harvested and measured for height, leaf area and fresh and dry mass of leaves, petioles, stems, roots and total mass. From these data, specific leaf mass, leaf succulence and stem water content levels were calculated. The results indicated that according to increased nutritive solution concentration, plant shoots had up to a two-fold increase in height, and that a decrease in these concentrations caused drastic root and total dry mass reduction. At full concentration, there was a tendency towards dry mass allocation in roots. Comparatively, leaf traits were very sensitive to nutritional level without affecting leaf succulence. Contrastingly, relative to stems, these values significantly increased according to increased nutritive concentration. It could be concluded that beyond its productive importance, the nutritional level available to these plants exerts a positive influence on tissue water contents of succulent stems, whose ecophysiological importance demand additional studies. key words: Leaf area, relative concentration of nutritive solution, specific leaf dry mass, stem succulence.

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Section: Methodsmentioning

confidence: 99%

The relationship between succulence and shoot biomass differences according to nutritional status in Jatropha curcas L.

Santos¹,

Silva²,

França³

et al. 2015

Afr. J. Agric. Res.

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“…www.intechopen.com Applied Photosynthesis 90 Moreira et al (2009), in a comparative study regarding photosynthetic and structural features in leaves of Dichaea cogniauxiana and Epidendrum secundum, noted that diurnal titratable acidity fluctuations indicate the presence of CAM in the second species. Moreover, several morphological features in E. secundum leaves are typical of plants with this photosynthetic pathway, including the occurrence of a thick mesophyll with few stomata and a wide cuticle.…”

Section: Crassulacean Acid Metabolism In Orchid Leavesmentioning

confidence: 99%

“…C 3 root photosynthesis can be found in CAM orchids, but CAM in roots was not found in C 3 orchids. Moreira et al (2009) worked with leaves and roots of the C 3 Dichaea cogniauxiana and the CAM Epidendrum secundum and observed that roots of both species had ratios of 13 CO 2 / 12 CO 2 and titratable acid fluctuation typical of a C 3 plant. Gehrig et al (1998) analyzed the photosynthetic behavior and isolated the different forms of PEPC in leaves, stem and aerial roots of the obligate CAM Vanilla planifolia.…”

Section: Photosynthesis On Aerial Roots and Presence Of Cammentioning

confidence: 99%

Crassulacean Acid Metabolism in Epiphytic Orchids: Current Knowledge, Future Perspectives

Kerbauy¹,

Takahashi²,

Lopez³

et al. 2012

Applied Photosynthesis

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“…Structural characteristics from roots, stems and leaves include tissues specialized in water absorption in roots, and leaf and stem succulence (Benzing et al 1983, Moreira & Isaias 2008. Physiologically, the crassulacean acid metabolism (CAM) provides important water economy by stomata closure during the day (Lüttge 2004), and photosynthesis in roots helps themselves in the maintenance of oxygen supply (Dycus & Knudson 1957, Erickson 1957, Moreira et al 2009). …”

mentioning

confidence: 99%

“…This is a common feature in epiphytic Orchidaceae, and is provided by epidermis with thick cuticle, large mesophyll cells with specialized wall thickenings, and large vacuoles. Succulence is intimately linked to CAM, since vacuolated cells are necessary for water storage, and for organic acid accumulation at night (Griffiths et al 1986, Jiménez & Morales 1987, Cushman 2001, Moreira et al 2009). …”

mentioning

confidence: 99%

Adaptaciones estructurales de dos orquídeas epífitas simpátricas (Orchidaceae) en un bosque nuboso de un campo rupestre del sureste de Brasil

Moreira

Filho

Isaías

2013

RBT

Self Cite

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Adaptaciones estructurales de dos orquídeas epífitas simpátricas (Orchidaceae) en un bosque nuboso de un campo rupestre del sureste de Brasil. The survival of plants in epiphytic environments depends on vegetative adaptations capable to defraud different stresses. Based on the structural diversity of the Orchidaceae, the current study has the objective of relating the anatomical structure of Dichaea cogniauxiana and Epidendrum secundum with the distinct environments where they live. It was expected that, despite structural similarities as strategies for resource acquisition, some peculiar variations related to the distinct light microenvironments (inside or in the edge of the nebular forest, near to "campo rupestre" area) might be found. Leaves and roots of both species were collected in a nebular forest located at a "campo rupestre" area at Serra da Piedade, Brazil), in January and February 2005. D. cogniauxiana is adhered to trunks, in sites with high atmospheric humidity and shaded, while E. secundum is located at the edge of the nebular forest, in more luminous sites. The leaves of E. secundum had thicker cuticle and higher number of stomata per area than those of D. cogniauxiana, characteristics coherent with their distinct pattern of exhibition to sun light. The suprastomatic chambers formed by the thicker cuticle may function as a barrier of resistance to water evaporation. The succulence of the leaves of E. secundum propitiates organic acids storage at night, and the storage of starch may be involved in PEP-carboxylase metabolism, both propitiating CAM mechanism. Roots with larger number of cell layers of the velamen, and specialized thick walled cortical cells (both in E. secundum) help water absorption and indicate better adaptation to an environment with intense solar radiation and a probable higher water deficit. The remarkable cell wall thickening of E. secundum exodermis can confer more efficient protection against the excess of transpiration at the border of the nebular forest. On the other hand, besides D. cogniauxiana be epiphyte, it is in a low position -in a shaded environment and with high relative humidity. Its thin thickened velamen permits the entrance of the low available light, and photosynthesis, producing oxygen and helping to avoid hypoxia condition. As features registered for D. cogniauxiana and E. secundum roots, we can depict the velamen, distinct exodermis and endodermis, and specialized thick walled cortical cells as characteristic of epiphytic plants. Rev. Biol. Trop. 61 (3): 1053-1065. Epub 2013 September 01.Key words: Orchidaceae, anatomy, epiphytic environments, ecological anatomy, histochemistry.The most species-rich family in the epiphytic flora is Orchidaceae, represented by more individuals than all other taxa together (Benzing 1987, Zotz 2004. Two out of three epiphyte species are orchids, and about 70% of the family is canopy-dependent (Benzing 1987). These plants exhibit structural and physiological mechanisms for carbon fixation, and water and nutrients acqu...

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Anatomy and photosynthetic parameters of roots and leaves of two shade-adapted orchids, Dichaea cogniauxiana Shltr. and Epidendrum secundum Jacq.

Cited by 30 publications

References 43 publications

The relationship between succulence and shoot biomass differences according to nutritional status in Jatropha curcas L.

The relationship between succulence and shoot biomass differences according to nutritional status in Jatropha curcas L.

Crassulacean Acid Metabolism in Epiphytic Orchids: Current Knowledge, Future Perspectives

Adaptaciones estructurales de dos orquídeas epífitas simpátricas (Orchidaceae) en un bosque nuboso de un campo rupestre del sureste de Brasil

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