RESUMO
The species Lippia integrifolia is an aromatic, sub-woody shrub, distributed from Northwest and Central Argentina to Bolivia. It is among the most important native aromatic species. It presents medicinal properties, some of which have been scientifically proven. As an alternative to harvesting, the process of domestication of the species was initiated. The objective of this work was to assess the phenotypic variability based on botanical-taxonomic and morpho-agronomic descriptors and the use of indicators to evaluate its natural situation in the west-center of Argentina. We worked in five wild populations, registering morphological variables, phenology, natural regeneration, herbivory and presence of diseases. L. integrifoliapresents a wide morphological variability, which can be explained with three morphological descriptors. Natural regeneration Ìs rate is very low to zero, in four of the sites. The results obtained are of importance to make decisions related to the sustainable use in situ, and to begin a program of domestication of the species.
La especie Lippia integrifolia es un arbusto aromático, sub-leñoso, distribuido desde el noroeste y centro de Argentina hasta Bolivia. Es una de las especies aromáticas nativas más importantes. Presenta propiedades medicinales, algunas de las cuales han sido científicamente probadas. Como alternativa a la cosecha, se inició el proceso de domesticación de la especie. El objetivo de este trabajo fue evaluar la variabilidad fenotípica basada en descriptores botánico-taxonómicos y morfo-agronómicos y el uso de indicadores para evaluar su situación natural en el centro-oeste de Argentina. Trabajamos en cinco poblaciones silvestres, registrando variables morfológicas, fenología, regeneración natural, herviboría y presencia de enfermedades. L. integrifolia presenta una amplia variabilidad morfológica, que puede explicarse con tres descriptores morfológicos. La tasa de regeneración natural es muy baja a cero, en cuatro de los sitios. Los resultados obtenidos son importantes para tomar decisiones relacionadas con el uso sostenible in situ y para comenzar un programa de domesticación de la especie.
Assuntos
Lippia/anatomia & histologia , Fenótipo , Argentina , Plantas Medicinais/anatomia & histologia , Produção Agrícola , Verbenaceae/anatomia & histologia , Variação Biológica da PopulaçãoRESUMO
The aim of this work was to develop an in vitro conservation protocol for Lippia alba that involved mineral oil and to study the leaf anatomy of L. alba genotypes in in vitro and ex vitro environments. In vitro conservation involved five genotypes; LA-13 and LA-57 (carvone chemotype); LA-22 (linalool chemotype); and LA-29 and LA-44 (citral chemotype). Each genotype was treated with mineral oil, with water, and a control at 18°C and 23°C. Survival (%), shoot height (cm) and leaf color were assessed at 180 and 270 days. The genotypes with the best in vitro conservation outcomes (LA-13 and LA-57) were used to study the anatomy of the leaves. Midrib thickness, leaf blade thickness, adaxial and abaxial cuticles and the number of glandular and tector trichomes were assessed. A temperature of 18°C was optimal for the conservation of genotypes of the carvone chemotypes. The explants were short and had green leaves. This was especially true for LA-57, whose height did not exceed 2.0 cm. At 270 days, the LA-13 and LA-57 genotypes continued to have green and viable leaves, especially LA-57, which had the lowest mean height. Field plants of the carvone chemotype had thicker midribs, leaf blades, and cuticles and had more trichomes. The LA-57 genotype had the most glandular and tector trichomes.
O objetivo deste estudo foi desenvolver um protocolo de conservação in vitro com óleo mineral e estudar a anatomia foliar de genótipos de L. alba nos ambientes in vitro e ex vitro. A conservação in vitro constou de cinco genótipos LA-13 e LA-57 (quimiotipo carvona); LA-22 (quimiotipo linalol); LA-29 e LA-44 (quimiotipo citral), três tratamentos (com óleo mineral, com água e controle) e duas temperaturas 18 e 23°C. Aos 180 e 270 dias, avaliou-se a sobrevivência (%), altura da parte aérea (cm) e coloração das folhas. Os genótipos com os melhores resultados da conservação in vitro (LA-13 e LA-57) foram utilizados para estudos de anatomia. Avaliou-se espessura da nervura central, espessura do limbo foliar, cutículas adaxial e abaxial e quantidade de tricomas glandulares e tectores. A temperatura a 18°C foi a ideal para a conservação dos genótipos do quimiotipo carvona, com folhas verdes e baixos valores para altura, destacando-se LA-57 cuja altura não ultrapassou 2,0 cm. Aos 270 dias LA-13 e LA-57 permaneceram com folhas verdes e viáveis, com destaque para LA-57 com menores médias de altura. A anatomia do quimiotipo carvona mostrou que as plantas de campo apresentaram maiores espessuras da nervura, limbo e cutículas, e maiores quantidades de tricomas. O genótipo LA-57 obteve a maior quantidade de tricomas glandulares e tectores.
Assuntos
Técnicas In Vitro , Óleos Voláteis , Verbenaceae , Lippia/anatomia & histologiaRESUMO
Morphology, anatomy, ontogeny and chemical composition of inflorescences volatile secondary metabolites of Lippia alba (Verbenaceae) at three stages of development. There is an increased interest to know and scientifically validate traditional knowledge of medicinal plants. Lippia alba belongs to Verbenaceae family and has been of interest, not only because of its worldwide extensive distribution, but also for its variable use as antiviral, bactericide, citostatic, analgesic and sedative. To study this, the morphology and ontogeny of Lippia alba inflorescences and the chemical composition of its volatile secondary metabolites were analyzed during three different stages of development. Plants were collected at the experimental crop field in CENIVAM, Bucaramanga, Colombia. The inflorescences morphology and ontogeny, and the chemical composition of volatile secondary metabolites were analyzed using a stereoscopic microscope and chromatographic and spectroscopic techniques. Fresh material corresponding to each stage was fixed in F.A.A (formol, acetic acid and alcohol), included in paraffin and cutted in transversal and longitudinal sections. Sections were stained with safranine-fastgreen, photographed and decribed. The chemical composition of volatile secondary metabolites at each ontogenic stage, was extracted by solid phase micro-extraction in the headspace mode and analyzed by gas chromatography coupled to mass spectrometry. Stage I showed a meristematic mass of cells in vegetative apex and bracts, with an outline of floral whorls. In Stage III, the stamens were adnate, epipetals and didynamous, bicarpelar and syncarpic gynoecium, with superior ovary and decurrent stigma. The main secondary metabolites detected were the bicyclosesquiphellandrene followed by carvone, limonene and trans-β-farnesene, that constituted the 78% of the total relative amounts of compounds. Other metabolites such as β-copaene, γ-amorphene and cis-β-guaiene, were reported for the first time in this study. When compared to other studies, morphological differences reported in this study are possibly related to adaptation to environmental conditions or pollinators, which let us suggest that there is no specific ontogenic pattern. Similarly, the qualitative and quantitative variations in the detected compounds could be explained because one or more of them are used as precursors of others. Rev. Biol. Trop. 58 (4): 1533-1548. Epub 2010 December 01.
La especie Lippia alba (Verbenaceae) llama la atención de los investigadores por su amplia distribución en todo el mundo y sus diversas propiedades. Se establecieron tres etapas durante el desarrollo de sus inflorescencias, fueron recolectadas en Bucaramanga, Colombia para analizar los cambios morfoanatómicos. Para ello, las muestras se trataron mediante la técnica safraninafastgreen y se observaron utilizando microscopio óptico convencional. Se realizó el aislamiento de los metabolitos secundarios volátiles usando la técnica de microextracción en fase sólida en el modo headspace (HS-SPME) y su posterior análisis de componentes, mediante cromatografía de gases acoplada a espectrometría de masas (GC-MS). En la Etapa I se observó una masa de células meristemáticas en el ápice vegetativo. En la Etapa II la acción de procesos morfogenéticos dan paso a la formación de los verticilos florales del perianto. En la Etapa III se establecen todos los verticilos florales. Los principales metabolitos secundarios constituyen el 78% de la cantidad relativa total. Ellos son el biciclosesquifelandreno, la carvona, el limoneno y el trans-β-farneseno. Los metabolitos β-copaeno, γ-amorfeno y cis-β-guaieno, no estαn registrados en la bibliografνa revisada. Estos compuestos activos pueden variar de acuerdo con el estado de desarrollo de la planta, la parte empleada para la extracciσn y el mιtodo implementado para ello.