ABSTRACT
RESUMEN Talinum paniculatum es una hierba adventicia ampliamente distribuida en Argentina, que tiene importancia económica como maleza de cultivos resistente a herbicidas. Esta especie se presenta en el campo con dos morfotipos y ellos se distinguen por la forma, tamaño y color de sus flores, frutos y hojas. El objetivo de este trabajo fue determinar las características morfo-anatómicas (de hoja y tallo), citogenéticas y moleculares en dos morfotipos de la provincia de Tucumán (Argentina), y establecer diferencias entre ellos. Se utilizaron técnicas morfo-anatómicas y citogenéticas clásicas y se realizaron análisis moleculares con el marcador ITS2. Los resultados evidencian que las características morfológicas, anatómicas, citogenéticas y moleculares de Talinum paniculatum permitieron diferenciar los morfotipos MT1 y MT2. Se concluye que el MT1 corresponde a T. paniculatum y el MT2 a un taxón diferente que aún no se mencionó para la flora de Argentina.
ABSTRACT Talinum paniculatum is an adventitious herb widely distributed in the Argentina. This plant is considered as an economically important herbicide-resistant weed. This species shows two morphotypes in the field which are differentiated by shape, size and colour of their flowers leaves and fruits. The aims of this work were to determinate morpho-anatomical (leave and stem), cytogenetic and molecular traits of two morphotypes from Tucumán province (Argentina) and to establish differences between them. Classical morpho-anatomical and cytogenetic techniques were used, molecular analysis based on the ITS2 marker were performed. The results showed that morphological, anatomical, cytogenetic and molecular traits of T. paniculatum allow us to differentiate the MT1 and MT2 morphotypes. We concluded that MT1 match with T. paniculatum and MT2 is a different taxon still not described for the flora of Argentina.
ABSTRACT
Abstract Larrea divaricata Cav., L. cuneifolia Cav. and L. nitida Cav., Zygophyllaceae, are evergreen xerophytic shrubs occurring in Northwestern Argentina used in traditional medicine. The aim of this work was to characterize the morphology, anatomy and histochemistry of the vegetative organs of three Larrea species by light and scanning electron microscopy in order to provide supporting data for their correct identification and to determine the site of synthesis and accumulation of its main active compounds. The shape, number and percentage of coalescence of leaflets, presence or absence of mucrones and rachis and the shape of the stipules represented the main botanical differences between the studied Larrea species. Anatomically three species presented amphystomatic leaves, with thick resinous slightly striated cuticle with resinous deposits, polygonal epidermal cells with straight anticlinal walls, ciclocytic, brachy-paracytic and paracytic stomatal types, non-glandular trichomes and isolateral mesophyll. The position and abundance of the sclerenchyma at the mid vein and petiole transection allows the differentiation of the three species, been more abundant in L. cuneifolia. Secondary phloem and parenchyma cells presented abundant calcium oxalate druses and solitary rhomboidal crystals. Epidermal cells and cuticle layer of leaflets and stipules of the three species presented amber resin deposits and content which stained positively for polysaccharides, phenolic compounds, flavonoids and tannins, while mesophyll palisade cells showed small refracting droplets stained positively for lipophilic substances.