Influence of environment on the leaf morpho-anatomy and histochemical of the ayahuasca leaf: Populations cultivated in extra-Amazonian regions

Psychotria viridis Ruiz & Pav (Rubiaceae) occurs naturally throughout the Amazon and it is traditionally used by indigenous communities, being incorporated into religious use in urban contexts over the last few decades. It is known and cultivated in many regions of South America for possessing valuable bioactive alkaloids. In this paper, we described P. viridis leaf morphology, anatomy and histochemistry from three populations cultivated in the southeastern Brazil, in order to identify possible adaptations to local environment and management. All plants presented terminal stipules and basic morpho-anatomical patterns of leaves, consistent with most species of the genus, as heterogeneous dorsiventral mesophyll, uniseriate epidermis, presents large cells with prominent vacuoles and druses. Unicellular non-glandular trichomes and multicellular starry trichomes were present in the primary and secondary veins. Amphi-hypostomatic leaf pattern, not yet described for the species, was common in all studied plants. Variation in the presence of domatia in the same population indicates that this structure cannot be used for taxonomic determination of P. viridis, as already described for other species of the genus. Presence of secretory ducts and reduction in stomata density and leaf area represent the main morpho-anatomic adaptations of plants from drier and warmer climates. Histochemical tests were positive for alkaloids, polysaccharides, proteins and phenolic compounds, being negative for starch only in plants subjected to water stress. We concluded that the morpho-anatomical and histochemical alterations found in the plants of this study resulted from seasonal water deficit adaptations and to maintain or attract mutualistic organisms

Influence of environment on the leaf morpho-anatomy and histochemical of the ayahuasca leaf: Populations cultivated in extra-Amazonian regions

Psychotria viridis Ruiz & Pav (Rubiaceae) occurs naturally throughout the Amazon and it is traditionally used by indigenous communities, being incorporated into religious use in urban contexts over the last few decades. It is known and cultivated in many regions of South America for possessing valuable bioactive alkaloids. In this paper, we described P. viridis leaf morphology, anatomy and histochemistry from three populations cultivated in the southeastern Brazil, in order to identify possible adaptations to local environment and management. All plants presented terminal stipules and basic morpho-anatomical patterns of leaves, consistent with most species of the genus, as heterogeneous dorsiventral mesophyll, uniseriate epidermis, presents large cells with prominent vacuoles and druses. Unicellular non-glandular trichomes and multicellular starry trichomes were present in the primary and secondary veins. Amphi-hypostomatic leaf pattern, not yet described for the species, was common in all studied plants. Variation in the presence of domatia in the same population indicates that this structure cannot be used for taxonomic determination of P. viridis, as already described for other species of the genus. Presence of secretory ducts and reduction in stomata density and leaf area represent the main morpho-anatomic adaptations of plants from drier and warmer climates. Histochemical tests were positive for alkaloids, polysaccharides, proteins and phenolic compounds, being negative for starch only in plants subjected to water stress. We concluded that the morpho-anatomical and histochemical alterations found in the plants of this study resulted from seasonal water deficit adaptations and to maintain or attract mutualistic organisms(AU)

Leaf domatia in montane forest and Caatinga in the semiarid of Pernambuco State: Morphology and ecological implications / Domácias foliares em brejo de altitude e Caatinga no Semiárido pernambucano: morfologia e implicações ecológicas

Leaf domatia are cavity-shaped structures of different types or tufts of hairs located at the junction between ribs on the abaxial surface of the leaf blades of various families of angiosperms, serving as protection against phytophagous organisms by harboring beneficial mites, suggesting a mutualistic relationship. There is shortage of inventories of species with such structures; thus the present study examined native woody plant in two habitats of the backwoods of Pernambuco to identify the types of leaf domatia. 86 species were observed,43 inCaatinga area, out of which five had domatia, and43 inthe montane forest, 11 species with domatia. Four types of domatia were observed: hairtufts, pocket, pit and revolute margin. There was predominance of plant species with leaf domatia in the area Carro Quebrado in Triunfo,PernambucoState. These results corroborate the information available in the literature in which domatia are prevalent in more humid environments, and that these structures as micro-habitats influence the maintenance of diverse organisms.(AU)

Domلcias foliares sمo estruturas em forma de cavidades de diferentes tipos ou tufos de tricomas localizados na junçمo entre as nervuras, na face abaxial das lâminas foliares de diversas famيlias de angiospermas, servindo de defesa contra organismos fitَfagos por abrigarem لcaros benéficos, sugerindo uma relaçمo mutualيstica. Hل escassez de inventلrios de espécies apresentando essas estruturas; diante disso, o presente estudo analisou plantas lenhosas nativas em dois ambientes do sertمo de Pernambuco, visando identificar os tipos de domلcias foliares. Foram observadas 86 espécies, 43 em لrea de Caatinga em as quais cinco apresentaram domلcias e 43 no brejo de altitude, 11 espécies com domلcias. Foram encontrados quatro tipos de domلcias: tufo de pelos, bolso, cova e orla. Na لrea do Carro Quebrado, Triunfo, Estado do Pernambuco, as plantas com domلcias foliares foram predominantes. Estes resultados corroboram as informaçُes disponيveis na literatura de que domلcias sمo predominantes em ambientes mais ْmidos, e que essas estruturas como micro-habitats, influenciam a manutençمo de diversos organismos.(AU)