Martinez J.G.,CONICET |
Ponessa G.,Institute Morfologia Vegetal
Quaternary International | Year: 2013
The main objective is to present the discovery of a wild species of the Amaranthus genus found within an archaeological site whose general context corresponds with hunter-gatherer settlements dated between ca. 7910 and 7270BP. Numerous seeds were collected at various stratigraphic layers of Peñas de la Cruz 1.1 site (PCz1.1), a rockshelter located in the Southern Argentinian Puna, in Antofagasta de la Sierra (Catamarca, NW Argentina). The implications of the findings are assessed in relation to the subsistence for these groups traditionally known as camelid hunters. In the overall context of the South-central Andes, the presence of these seeds might indicate early practices in the handling of wild plant species intended for human consumption during the initial mid-Holocene. © 2013 Elsevier Ltd and INQUA.
Coll Araoz M.V.,PROIMI Biotecnologia |
Mercado M.I.,Institute Morfologia Vegetal |
Catalan C.A.N.,National University of Tucuman
Chemoecology | Year: 2016
According to theory, variation in plant secondary metabolism against herbivores is driven by variation in biotic and abiotic conditions interacting with plants genotype to determine the expression of resistance traits. Particularly, it has been long postulated that plants growing along latitudinal gradients experience changes in biotic and abiotic interactions, specifically leading to a decrease of plant toxicity towards the poles. We tested this hypothesis using the asteraceous species Smallanthus macroscyphus. Smallanthus species are known to contain sesquiterpene lactones (STLs), bitter compounds with a broad spectrum of biological activities, including deterrence to herbivores. S. macroscyphus showed a decrease in chemical diversity of STLs when investigating populations growing from the tropical regions to less tropical ones. Populations from lower latitudes were found to be more chemically diverse with enhydrin, uvedalin and fluctuanin as main components, while populations southward were chemically fairly uniform, with polymatin A as the main and largely dominant STL. The STL chemistry of S. macroscyphus is in agreement with the hypothesis that plants of tropical forests have a greater diversity of secondary metabolites when compared to their temperate counterparts. © 2016 Springer International Publishing
Morpho-anatomy, imbibition, viability and germination of the seed of anadenanthera colubrina var. cebil (fabaceae) [Morfo-anatomía, imbibición, viabilidad y germinación de las semillas de anadenanthera colu-brina var. cebil (fabaceae)]
Varela R.O.,Institute Ecologia |
Varela R.O.,National University of Chilecito |
Albornoz P.L.,Institute Morfologia Vegetal |
Albornoz P.L.,National University of Tucuman
Revista de Biologia Tropical | Year: 2013
Seed biology is a relevant aspect of tropical forests because it is central to the understanding of processes of plant establishment, succession and natural regeneration. Anadenanthera colub-rina var. cebil is a timber tree from South America that produces large seeds with thin weak teguments, which is uncommon among legumes. This study describes the morphology and anatomy of the seed coat, the viability, imbibition, and germination in this species. Seeds used during the essays came from 10 trees that grow naturally in Horco Molle, province of Tucumán, Argentina. Seed morphology was described from a sample of 20 units. The seed coat surface was examined with a scanning electron microscope. Transverse sections of hydrated and non-hydrated seeds were employed to describe the histological structure of the seed coat. Hydration, viability and germination experiments were performed under laboratory controlled conditions; and the experimental design consisted of 10 replicas of 10 seeds each. Viability and germination tests were conducted using freshly fallen seeds and seeds stored for five months. Morphologically the seeds of A. colubrina var. cebil are circular to subcircular, laterally compressed, smooth, bright brown and have a horseshoe fissure line (=pleurogram) on both sides. The seed coat comprises five tissue layers and a double (external and internal) cuticle. The outer cuticle (on the epidermis) is smooth and interrupted by microcracks and pores of variable depth. The epidermis consists of macroesclereids with non-lignified secondary walls. This layer is separated from the underlying ones during seed hydration. The other layers of internal tissues are comprised of osteosclereids, parenchyma, osteo-sclereids, and macrosclereids. The percentage of viable seeds was 93%, decreasing to 75% in seeds with five months old. Seed mass increased 76% after the first eight hours of hydration. Germination percentage was 75% after 76 hours. Germination of seeds stored for five months decreased to 12%. The results showed that seeds of A. colubrina var. cebil are highly permeable and germinate directly without a dormant period.
Hernandez M.A.,Institute Morfologia Vegetal |
Teran L.,Institute Morfologia Vegetal |
Mata M.,Institute Morfologia Vegetal |
Martinez O.G.,National University of Salta |
Prado J.,Institute Botanica
American Fern Journal | Year: 2014
The occurrence of helical cell wall thickenings in fern roots is not well investigated and there are few records about it in the literature. To assess the presence of thickenings and their chemical composition, we studied all species of Polypodiaceae, which grow in northwestern Argentina, using light microscopy, scanning electron microscopy, and fluorescence microscopy. Twenty of the twenty-one species studied showed the thickening in the roots. Only in Melpomene peruviana are helical cell wall thickenings absent. All thickenings have cellulose as the main compound. The structure of the thickening may be classified as simple, furcate, or anastomosing. All data presented in this paper corroborate the same structure and chemical composition of thickenings previously reported for Aspleniaceae. © 2014, American Fern Society.
Grosso T.P.,Instituto Nacional de Tecnologia Agropecuaria |
Mercado M.I.,Institute Morfologia Vegetal |
Ponessa G.I.,Institute Morfologia Vegetal |
Conci L.R.,Instituto Nacional de Tecnologia Agropecuaria |
Neotropical Entomology | Year: 2016
Piercing-sucking insects cause mechanical and physiological injury to plants. Ceresa nigripectus Remes Lenicov is a pest of alfalfa in subtropical regions of South America and a carrier of the ArAWB phytoplasma. The aim of this study was to determine the feeding habits of this treehopper and to describe the effects of the feeding injuries on stem vascular tissues in alfalfa. Adults and nymphs of C. nigripectus inserted their stylets repeatedly girdling the stem. One week after feeding, alfalfa stems exhibited numerous feeding canals with salivary deposits, most of which reached the phloem. Two weeks after feeding, cortex and phloem cells next to the salivary sheath collapsed, mature tracheal elements became sparse and appeared with an increased cross-section area, and phenolic compounds increased in cells and cell walls compared to undamaged plants. Three weeks after feeding, an annular callus, formed by abnormal cell division and hypertrophy of preexisting cortex and vascular cambium cells, appeared immediately above the stem girdle. Parenchyma cells from the outer layers of the callus differentiated to form secondary anomalous amphicribal bundles in the wound. The aerial parts above the stem girdle eventually withered and died. © 2015, Sociedade Entomológica do Brasil.
PubMed | Institute Morfologia Vegetal, CONICET and Instituto Nacional de Tecnologia Agropecuaria
Type: Journal Article | Journal: Neotropical entomology | Year: 2016
Piercing-sucking insects cause mechanical and physiological injury to plants. Ceresa nigripectus Remes Lenicov is a pest of alfalfa in subtropical regions of South America and a carrier of the ArAWB phytoplasma. The aim of this study was to determine the feeding habits of this treehopper and to describe the effects of the feeding injuries on stem vascular tissues in alfalfa. Adults and nymphs of C. nigripectus inserted their stylets repeatedly girdling the stem. One week after feeding, alfalfa stems exhibited numerous feeding canals with salivary deposits, most of which reached the phloem. Two weeks after feeding, cortex and phloem cells next to the salivary sheath collapsed, mature tracheal elements became sparse and appeared with an increased cross-section area, and phenolic compounds increased in cells and cell walls compared to undamaged plants. Three weeks after feeding, an annular callus, formed by abnormal cell division and hypertrophy of preexisting cortex and vascular cambium cells, appeared immediately above the stem girdle. Parenchyma cells from the outer layers of the callus differentiated to form secondary anomalous amphicribal bundles in the wound. The aerial parts above the stem girdle eventually withered and died.
Ruiz V.E.,CONICET |
Interdonato R.,Catedra de Fisiologia Vegetal |
Cerioni L.,CONICET |
Albornoz P.,Institute Morfologia Vegetal |
And 4 more authors.
Journal of Photochemistry and Photobiology B: Biology | Year: 2016
UV-B radiation (UVBR) is a small fraction of the solar spectrum from 280 to 315 nm. UVBR produces photomorphogenic acclimation responses in plants, modulating their cellular structure and physiology. Here, changes in the peel of harvested lemons after short time exposure to UVBR were analyzed and its potential effects against fungal infection were studied. In the flavedo, UVBR treatment induced variations in the respiratory profiles and increased the phenolic compound contents. Final products of the flavonoid pathway (flavones, flavonols and anthocyanins) increased more markedly than their precursors (flavanones and dihydroflavonols). The increased accumulation of soluble phenolics in the flavedo of treated lemons is associated with the high antioxidant activity found in the flavedo of these samples. Supporting the biochemical determinations, anatomical observations showed abundant intravacuolar deposits of phenolic compounds and an increase in the cell wall thickness in UVBR-treated samples. Metabolic and anatomical modifications associated to UVBR improved natural defenses against Penicillium digitatum, the causal agent of green mold disease. Our results suggest that mature postharvest lemons exposed to the artificial radiation showed phenotypic plasticity, allowing an acclimation response to UVBR which confers fruit resistance to pathogens. Thus, combination of UVBR with other treatments could represent an important improvement to control postharvest diseases on citrus. © 2016 Elsevier B.V. All rights reserved.
Socolsky C.,CONICET |
Hernandez M.A.,Institute Morfologia Vegetal |
Studies in Natural Products Chemistry | Year: 2012
Acylphloroglucinols are derivatives of benzene-1,3,5-triol, a compound also known as phloroglucinol. In ferns, phloroglucinols are usually made of two or more rings linked together through methylene bridges. The occurrence of acylphloroglucinols in ferns has been associated with the presence of secreting glands located in their rhizomes. Several phloroglucinol derivatives from ferns display different biological activities including anthelmintic, molluscicidal, and antibacterial effects. This chapter covers in detail not only the distribution of acylphloroglucinols in ferns but also their location in the plant, detection and isolation procedures, structure, and biological activity. © 2012 Elsevier B.V.
PubMed | CONICET, Institute Morfologia Vegetal and National University of Tucuman
Type: | Journal: Journal of plant research | Year: 2017
Yacon (Smallanthus sonchifolius, Asteraceae) is an ancient andean crop that has numerous dietary and medicinal properties. Morphological and anatomical features and developmental changes of the capitulum were studied. A ray floret is a pistillate, female flower, while a disc floret is a staminate male flower, and the former opens before the latter, being pseudanthium protogynous. The capitulum presents interesting attributes for pollinators such as flower structure, nectaries and pollenkitt. Gynoecial nectaries were found on undeveloped ovary in the disc floret, but not in the ray floret. Glandular trichomes were observed on the abaxial epidermis of corolla in the ray floret, but not in the disc floret. Capitulum development was divided into eight stages. Stigma receptivity varied with these stages. Pollen viability was low (15%). In accordance with low viability, pollen grains exhibit diverse sizes and shapes, reduction in length of spines, and abnormal protoplasm. Examination of ovary development in the ray floret showed that a mature ovule was formed, but fertilization did not occur. In advanced developmental stages, the capitulum showed proliferation of the endothelium, degeneration of the embryo sac, and all harvested cypselae had aborted seeds. Problems found in pollen viability and aborted cypselae could be the result of a history of vegetative propagation in the domestication process.
Coll Araoz M.V.,Institute Morfologia Vegetal |
Coll Araoz M.V.,National University of Tucuman |
Kortsarz Gonzalez A.M.,National University of Tucuman |
Mercado M.I.,Institute Morfologia Vegetal |
And 3 more authors.
Genetic Resources and Crop Evolution | Year: 2014
The ontogeny of the tuberous roots of yacon (Smallanthus sonchifolius), an ancient Andean crop, is described for the first time along with three other wild species of Smallanthus: S. connatus, S. macroscyphus and S. siegesbeckius. Tuberous storage roots are present in the four species. Tuberization results from unusual secondary thickening. A meristematic endodermis maintains the primary cortex by generating cortex cells continuously. Secretory schizogenous canals develop adjacent to the endodermis in opposition to the phloem poles. Phellogen originates in the outer layers of the parenchymatic cortex. The four species develop a parenchymatous pith that stores mainly fructooligosacharides (FOS) and plays an important role in storing water, protecting the plant from drought stress and environmental hazards in the Andean climate. In yacon, domestication has produced a wide pith that stores water, reducing sugars and FOS with low degree of polimerization, that could have eventually made it more palatable as compared to the wild counterparts. © 2013 Springer Science+Business Media Dordrecht.