Paulo Henrique Pereira Peixoto

Floração, germinação e estaquia em espécies de Lippia L. (Verbenaceae)

Plantas de dez especies de Lippia foram coletadas na Cadeia do Espinhaco, MG, Brasil e cultivadas em canteiros em Juiz de Fora, MG. A epoca de florescimento das especies de Lippia foi observada nos ambientes de origem e em canteiro. A germinacao foi testada com sementes coletadas em ambiente natural. Os materiais estabelecidos ex situ foram avaliados quanto ao enraizamento de estacas. As analises das plantas em ambiente natural e das cultivadas em canteiro evidenciaram que a maioria das especies estudadas apresenta floracao no periodo seco (inverno), enquanto um menor numero, no chuvoso (verao). Uma unica especie floresceu nessas duas estacoes. Em cultivo controlado, o periodo de floracao das especies com floracao caracteristica no verao foi aumentado. Algumas especies germinaram melhor quando recem coletadas enquanto outras quando armazenadas, evidenciando a ocorrencia de perda de viabilidade e de dormencia. O GA3 estimulou a germinacao em algumas especies, enquanto inibiu ou nao apresentou efeitos sobre outras. Sementes de algumas especies germinaram melhor no escuro, enquanto de outras sob luz branca, existindo ainda especies que germinaram tanto na luz quanto no escuro. O enraizamento das estacas das especies nao domesticadas de Lippia foi muito baixo, independente da estacao do ano e da concentracao da auxina. O enraizamento em estacas de L. alba (Mill.) N.E. Br. variou em resposta a epoca de coleta das estacas e quanto ao tipo e a concentracao das auxinas utilizadas. Os resultados do presente trabalho constituem os primeiros relatos envolvendo a reproducao de especies de Lippia endemicas da Cadeia do Espinhaco. Eles indicam a possibilidade de utilizacao das sementes na propagacao das plantas desse genero e tambem evidenciam que a reproducao das plantas das especies nao domesticadas de Lippia atraves de tecnicas convencionais de propagacao assexuada apresenta eficiencia bastante reduzida.

Analysis of the chemical composition of the essential oils extracted from Lippia lacunosa Mart. & Schauer and Lippia rotundifolia Cham. (Verbenaceae) by gas chromatography and gas chromatography-mass spectrometry

Lippia lacunosa and L. rotundifolia (Verbenaceae) are two Brazilian species of complex taxonomic delimitation. The composition of the essential oils from leaves and flowers of these plants was investigated by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS) analysis. The major components of the essential oils of flowers and leaves of L. lacunosa were: myrcene (14.7% and 11.9%), myrcenone (45.2% and 64.2%), Z-ocimenone (5.7% and 5.2%), and E-ocimenone (14.7% and 4.1%), respectively; whereas in L. rotundifolia (flowers and leaves) were a-pinene (8.7% and 1.8%), myrcene (5.1% and 3.6%), limonene (26.0% and 7.9 %), cis-pinocamphone (4.5% and 3.1%) and myrtenal (22.3% and 16.7%), respectively. The essential oils from L. lacunosa exhibited a strong and pleasant mango aroma, which was related to the presence of myrcene and myrcenone. The marked differences in the chemical composition of their essential oils may represent a powerful tool for the botanical classification.

IN VITRO PROPAGATION OF ENDANGERED LIPPIA FILIFOLIA MART. AND SCHAUER EX SCHAUER

SummaryThis work describes an efficient micropropagation protocol of Lippia filifolia. Nodal segments cultivation in MS medium supplemented with 6-benzylaminopurine (4.5 μM)/α-naphthaleneacetic acid (NAA; 54nM) induced multiple shoots (in average 27 shoots per explant). Elongated shoots were rooted with NAA (0.11 μM) and they maintained ploidy level of the in vitro produced explants. The basic chromosome number were 2n=2x=24. Regenerated rooted shoots were successfully acclimatized under shading house conditions. This is the first report involving the establishment of a protocol for shoot multiplication and rooting for endangered L. filifolia, contributing for germplasm preservation of this species.

Efeitos do flúor em folhas de plantas aquáticas de Salvinia auriculata

Abstract – The objective of this work was to evaluate the effects of fluoride on leaves of aquatic Salviniaauriculata Aubl., to supply subsidies for the use of this species as an environmental pollution bioindicator. Theplants were cultivated under controlled conditions in pots containing nutritive solutions, and were submitted tosimulated rain containing KF, in concentrations of 0, 13, 26 and 39 mM, in the morning, during five consecutivedays. Results evidenced the occurrence of morphological and anatomical damages involving trichome andadaxial surface of the leaf necrosis. Alterations in the activity of peroxidase, polyphenoloxidase, superoxidedismutase, and catalase enzymes indicated the occurrence of oxidative damages in response to fluoride, althoughlipid peroxidation tests showed negative results. Alterations in pigment concentration also pointed to theoccurrence of oxidative stress, caused by fluoride present in the simulated rain. The morphological, anatomical,enzymatic, and pigment composition alterations in

Alterações morfológicas e acúmulo de compostos fenólicos em plantas de sorgo sob estresse de alumínio

The Al+3 effects on the morphology and on the phenolics accumulation were evaluated in two sorghum cultivars exhibiting differential tolerance to Al+3. The plants were kept in nutrient solution, for ten days, in the presence (185 mM) or Al+3 absence. The root apexes were colored with ferric hematoxylin, and because the intensity of color development is very similar among evaluated cultivars, the use of this method as a selection parameter for Al+3-tolerance is not indicated. Analyses of superficial and internal morphology from tissues treated with Al+3 also expressed very similar alterations among the two cultivars, not allowing its use for selection between sensitive and Al+3-tolerant genotype. The higher lignin accumulation and, mainly, the lower phenolics production in roots of the BR006R cultivar in Al+3s presence, demonstrated the existence of differential tolerance among cultivars.

Antioxidant system response induced by aluminum in two rice cultivars

The antioxidant defense system response was evaluated in two rice cultivars (Oryza sativa L.), Fernandes (CNA-1158) and Maravilha (CNA-6843-1), treated with toxic levels of aluminum. After exposure to aluminum we determined plant growth, H2O2 and O2•- contents, lipid peroxidation, antioxidant enzymes activities and ascorbate and dehydroascorbate contents. Al predominantly accumulated in roots of both cultivars but it reduced root and shoot growth only in the Maravilha cultivar. Treatment with aluminum resulted in a reduction of 84 and 60% in the levels of H2O2 in the roots of the cultivars Maravilha and Fernandes, respectively, and of 26% in the levels of O2•- only in the roots of Fernandes cultivar. Increased lipid peroxidation was observed only in the roots of the Maravilha cultivar. In general, the antioxidant enzyme activities were higher in roots and increased in the presence of aluminum, especially in the Fernandes cultivar. The levels of ascorbate were higher in leaves and increased with aluminum treatment, while dehydroascorbate decreased in roots of both cultivars after aluminum treatment. However, the ascorbate/dehydroascorbate ratio increased in the roots of both cultivars after treatment with aluminum. Ascorbate, dehydroascorbate and ascorbate/dehydroascorbate levels found here point to an efficient regeneration of ascorbate, essential for the homeostasis of cellular metabolites involved in reactive oxygen species removal by rice plants treated with aluminum. Therefore, the higher tolerance of Fernandes to aluminum relative to Maravilha cultivar may be the result of better growth of the root system and shoots, higher antioxidant enzyme activities and a best use/regeneration of ascorbate.

Micropropagation, antinociceptive and antioxidant activities of extracts of Verbena litoralis Kunth (Verbenaceae)

This work describes an efficient micropropagation protocol for Verbena litoralis and the study of the antinociceptive and antioxidant activities in extracts of this species. For the establishment in vitro, surface-sterilization procedures and PVPP showed high efficiency in fungal-bacterial contamination and phenol oxidation controls. Nodal segments cultivation in MS medium supplemented with 6-benzyladenine (7.5 µM)/α-naphthaleneacetic acid (NAA; 0.005 µM) induced multiple shoots. Elongated shoots were rooted with IAA (0.2 µM). Acclimatization rates were elevated and the plants showed the typical features of this species. The hexanic fraction (HF) of powdered leaves presented a radical scavenging activity with IC(50) = 169.3 µg mL(-1). HF showed a non-dose dependent analgesic activity in the writhing test; its antinociceptive activity in the hot plate test was restricted to 500 mg kg(-1), which is the highest dose. The results of this study showed the potential of tissue culture on conservation and large scale multiplication and confirmed the traditional folk medicine use of V. litoralis.

Effects of light intensity on the distribution of anthocyanins in Kalanchoe brasiliensis Camb. and Kalanchoe pinnata (Lamk.) Pers

This paper compares two medicinal species of Kalanchoe, which are often used interchangeably by the population, regarding the distribution of anthocyanins under the influence of four luminosity levels for 6 months. For the morphoanatomical analysis, the 6th stem node of each plant was sectioned. Usual histochemical tests revealed the presence of anthocyanins by cross sections of the stems, petioles and leaf blades. The petioles and leaf blades were submitted to the extraction with acidified methanol, and the anthocyanins were quantified by spectrophotometric readings. At the macroscopic level, it was noticed for both species a higher presence of anthocyanins in stems and petioles of plants under full sunlight. The microscopy of K. brasiliensis stems evidenced the deposition of anthocyanins in the subjacent tissue to the epidermis and cortex, which increased with light intensity. In K. pinnata a subepidermal collenchyma was observed, which interfered in the visualization of anthocyanins. In petioles and leaf blades of K. brasiliensis the deposition of anthocyanins was peripheral, and in K. pinnata it was also throughout the cortex. The quantification of anthocyanins in petioles showed in 70% of light higher averages than in 25%, but in leaf blades there were no significant results. This study contributes to the pharmacognosy of Kalanchoe and it is sustained by the description of flavonoids as biological markers of the genus.

In vitro propagation and acclimatization of Lippia rotundifolia, an endemic species of Brazilian Campos Rupestres.

The importance in folk medicine, combined to threats in their environment, becomes necessary to carry out studies involving large-scale propagation of Lippia genus. Although the tissue culture propagation is widely disseminated for medicinal plants, for L. rotundifolia any article was published yet. The present study aimed to establish an efficient protocol for micropropagation of L. rotundifolia. Nodal segments, taken from plants collected in the Espinhaco Range, were disinfected, and cultures were initiated on MS medium with PVPP (1 g L - 1 ), sucrose (3%) and agar (0.7%). The culture were maintained in a growth room at controlled conditions. Disinfestation procedures and the supply of PVPP on culture media resulted in both reduced contamination and phenol oxidation rates, with more than 90% of viable cultures. In the multiplication phase were tried different BAP and NAA combinations supplied to the MS medium. The treatment that resulted in highest multiplication rates was 0.33 �� M BAP. The effects of NAA were evaluated for in vitro rooting. At 0.44 �� M, rooting was 70% higher than that observed in the control. The acclimatization was held in trays with substrate, coated with translucent plastic and kept under shade. The plantlets were transferred to the greenhouse after 15 days and transplanted to plant beds after 30 days. The acclimatized plantlets bloomed one year after the transference to field conditions, showing that the in vitro culture did not affect the vegetative and reproductive development, which confirms the potential of micropropagation to reduce the extinction risk of L. rotundifolia.

MICROPROPAGATION AND ACCLIMATIZATION OF Aegiphila verticillata Vell.: AN ENDANGERED WOODY SPECIES

The objective of this work was to establish an efficient protocol for in vitro multiplication and rooting, as well as ex vitro acclimatization of Aegiphila verticillata, a woody species found in Brazilian rocky fields. Aseptic cultures were established by seeds and two multiplication analyses were performed. In the first, we employed 6-benzylaminopurine (BAP - 0, 2.5, 5 and 7.5 μM) + α-naphthalene acetic acid (NAA - 0, 0.2, 0.4 and 0.6 μM) and, in the second, were studied adenine sulfate, kinetin and thidiazuron (0, 5, 7.5, 10 and 12.5 μM). After 90 days, we assessed the quantitative and qualitative shoot propagation. There were more than 90% seed germination and low contamination (2%). In multiplication phase, the culture medium that promoted the best quantitative and qualitative culture development was supplemented with 7.5 μM BAP + 0.4 μM NAA. In the rooting assay, were used NAA, indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) (0, 0.1, 0.2, 0.3 or 0.4 μM). After 90 days, the root number and rooting quality were evaluated. In this analysis, differences were not found between the control and the other treatments. Rooted plantlets were acclimatized in styrofoam trays for 30 days, after which they were transferred to pots in the greenhouse. Only 3% of the plants subjected to initial acclimatization died and 70% of the plants transferred to the field conditions survived and showed normal development. The results founded in this work are the first involving in vitro propagation and ex vitro acclimatization of Aegiphila verticillata and provide a continuous supply of this medicinal native species, endangered due anthropogenic activities.