III Um novo clorofilômetro para estimar os teores de clorofila em folhas do capim Tifton 85A new chlorophyll meter to estimate chlorophyll contents in leaves of Tifton 85 bermudagrass -NOTA - (clorofila a: r=0,646; b: r=0,797; e total: r=0,721)

Studies on phenols have gained attention owing to their abundance in plants and their effects on plant development. Phenols from forage grasses may exert phytotoxicity on legume crops in intercropping systems. We aimed to identify morpho-anatomical variations in Calopogonium mucunoides Desv. roots treated with phenolic compounds. Seeds of C. mucunoides were treated with (1) distilled water (control), (2) trans-cinnamic acid, (3) a mixture of the flavonoids quercetin, rutin, kaempferol and kaempferol-3-α-rhamnoside, or (4) a combination of the flavonoid mixture and trans-cinnamic acid. After 10 days of treatment, the roots were measured, described and processed according to standard techniques in plant anatomy. In general, non-control individuals showed plant lengths decreased by 40–45%, root-tip necrosis and intense lateral root ramification. Seeds germinated in cinnamic acid presented xylem poles with a greater number of cells and a greater emission of lateral roots. In the seeds treated with flavonoids, cell division was observed in the endodermis and the pericycle, and xylem fibres went through differentiation. The combination of cinnamic acid and flavonoids led to the premature formation of fibres by the phloem. The treatments with flavonoids or cinnamic acid alone were significantly greater in root diameter (868.61 µm and 810.35 µm, respectively) than was the application of both (714.98 µm) or the control (533.76 µm). The results suggest that cinnamic acid and the tested flavonoids negatively affect the development and the root structure of C. mucunoides.

Knowledge of allelopathic interactions between grasses and legumes can contribute for the successful establishment of mixed tropical pastures in Brazil. The purpose of this work was to evaluate the allelopathic effect of the hydrolate and water decoction ofBrachiaria humidicola(Rendle) plant parts (root, shoot, and seeds) on four tropical forage legumesStylosanthesspp. cv. Campo Grande,Macrotyloma axillare, Calopogonium mucunoides, Desmodium ovalifolium, and on lettuce (Lactuca sativaL.), this last species used as a sensitivity standard in allelopathic bioassays. The results obtained for roots and shoots showed, in the case of hydrolate, the highest inhibitory effect on germination rates of the receiving species, while seed hydrolates had a stimulating effect depending on the legume species. In contrast, water decoction extracts had the highest inhibitory effects on root and seed fraction, and the lowest on the shoot fraction. Regarding the receiving species, germination percentages ofM. axillareshowed higher tolerance to inhibitory effects of the aqueous extracts ofB. humidicola, whileD. ovalifoliumshowed the highest sensitivity.

This study aimed to assess which is the most appropriate protocol for extraction of chlorophylls a, b and total (a + b) to be applied in studies with Tifton 85 (Cynodon spp.) forage grass. Results revealed that, based on total (a + b)chlorophyll contents, the best extractors were N,Ndimethylformamide, dimethylsulfoxide and acetone 80% (using the equations proposed by ARNON, 1949). Temporal changes in the concentrations of chlorophyll a, b and total were well described by a hyperbolic model common to all solvents, being the period of 48 hours considered sufficient for an appropriate extraction.

The aim of this study was to identify the main classes of secondary metabolites present in the root and shoot crude extracts and fractions from the forage grass Urochloa humidicola (Rendle) Morrone & Zuloaga and to evaluate the allelopathic effect of these metabolites on forage legumes for intercropping. Phytochemical prospecting analyses, 1 H NMR and capillary electrophoresis were performed on extracts of U. humidicola. Allelopathic activity was evaluated in germination of Stylosanthes, Macrotyloma axillare and Lactuca sativa L. (standard) in the presence of crude extracts, isolated saponins, flavonoids and trans-cinnamic acid. The metabolite classes present in the extracts could be determined by the combined use of the tested analytical techniques, but their use alone was usually not sufficient to chemically characterize the species. Capillary electrophoresis was effective in detecting phenolic compounds. Macrotyloma axillare was tolerant to crude extracts of U. humidicola.Saponins and trans-cinnamic acid, but not the flavonoids, reduced germination of the target plants.

Procurou-se observar o desenvolvimento pós-embrionário de Chrysomya albiceps, testando-se, comparativamente, dietas à base de sardinha e carne eqüina. Os substratos frescos foram previamente mantidos a 30°C de temperatura durante duas horas. Foram inoculadas 50 neolarvas em 100g de dieta por repetição. Utilizaram-se quatro repetições por tratamento. O experimento foi conduzido em condições de laboratório. O peso médio das larvas após o abandono espontâneo das dietas foi de 91,19mg, no substrato à base de carne eqüina e 76,01mg, no substrato à base de sardinha, a diferença foi, portanto, significativa. A taxa de sobrevivência larval registrada foi superior a 80%, enquanto a taxa de sobrevivência pupal foi próxima a 100%. A razão sexual foi próxima a 0,5. A dieta à base de carne eqüina mostrou-se mais adequada ao desenvolvimento de C. albiceps, pois as larvas mantidas neste substrato apresentaram-se mais pesadas, o que potencializa a capacidade reprodutiva do adulto.

O manjericão é uma planta medicinal e seus metabólitos especiais são utilizados com fins terapêuticos e industriais. Este trabalho teve por objetivo avaliar técnicas e linhagens de Agrobacterium rhizogenes na produção de raízes transformadas de duas variedades de Ocimum basilicum L., Dark Opal (roxo) e Minete Anão (verde). Verificou-se o efeito da inoculação com linhagens de A. rhizogenes selvagens (A4, 8196, 9402, 2659, 2659 G, 17242, LBA, 15834) ou transformadas (R1601) em plantas inteiras ou explantes (folhas e segmentos de caule) de manjericão, cultivados em casa de vegetação ou in vitro. A inoculação com as linhagens LBA e 8196 possibilitou redução no número de explantes de folha de manjericão-verde oxidados, quando comparado ao controle. Dentre as linhagens selvagens, as que proporcionaram melhor indução na produção de raízes transformadas foram A4, LBA e 8196, respectivamente. Entretanto, a cepa R1601 apresentou a melhor resposta. Raízes foram eficientemente induzidas mediante a inoculação de explantes de manjericão-roxo e manjericão-verde e expressaram o fenótipo típico de raízes em cabeleira (hairy roots). As culturas clonais de manjericão-verde apresentaram rápido crescimento em meio de cultura livre de reguladores de crescimento.Palavras-chave: agrobactéria, cultura de raízes, manjericão, plantas medicinais. TRANSFORMATION TECHNIQUES AND Agrobacterium rhizogenes Strains In The Production Of Hairy Roots Of Ocimum basilicum L. ABSTRACT:Basil is a medicinal plant and its special metabolites are used for therapeutic or industrial purposes. The aim of this work was to evaluate Agrobacterium rhizogenes techniques and strains in the production of hairy roots of two varieties of Ocimum basilicum L., Dark Opal (purple) and Dwarf Racer (green). The effects of inoculation of A. rhizogene (A4, 8196, 9402, 2659, 2659, 2659 G, 17242, LBA, 15834) or (R1601) lines on whole plants or explants (leaves and stem segments) of basil, grown in a greenhouse or in vitro, in the production of hairy roots and calluses made by subcultures. Inoculation with the LBA and 8196 lines allowed a reduction in the number of oxidized basil-green leaf explants when compared to the control. Among the wild strains, those that had best ability to induce hairy root of hairy roots were A4, LBA and 8196, respectively. However, the R1601 laboratory strain had the best response. Roots were efficiently induced by the inoculation of explants basil-purple and basil-green and expressed the typical phenotype of hairy roots. Green-basal clonal cultures showed rapid growth in culture medium free of growth regulators.Keywords: agrobacterim, basil, medicinal plants, root culture. DOI:

Resumo -Este trabalho teve por objetivo a obtenção de raízes transgênicas (hairy roots) de Piper hispidinervium (pimenta-longa), espécie reconhecida pela produção de óleo essencial rico em Safrol, metabólito secundário utilizado com fins terapêuticos e industrial. As raízes foram produzidas a partir da infecção de explantes in vitro de pimentalonga com Agrobacterium rhizogenes (Estirpe R1601). Os resultados mostraram que a estirpe R1601 de A. rhizogenes foi eficiente para inoculação baseado na imersão de explantes em meio de cultura liquido, com a bactéria em crescimento, o que representou maior praticidade, menor índice de contaminação, maior taxa de infecção e menores danos aos explantes. A resposta morfológica foi a mesma entre os clones, não permitindo a distinção dos mesmos. Explantes de folha de pimenta-longa, inoculados com a estirpe R1601, formaram raízes que apresentaram crescimento nos subcultivos subsequentes. Palavras-chave -Piper hispidinervium, cultura de raízes, metabolitos secundários, cultivo in vitro.Abstract -This work aimed to obtain transformed roots of Piper hispidinervium (long pepper) specie recognized for the production of Safrol-rich essential oil, a substance already used for therapeutic and industrial purposes. The roots were obtained from the infection of the plants with strain R1601 of the bacterium Agrobacterium rhizogenes. The results show that A. rhizogenes strain R1601 was very efficient for inoculation based on the immersion of explants in liquid culture medium, with the growing bacterium, because it presents greater practicality, lower contamination index, higher infection rate and what causes less damage to the explants. A morphological response was observed that did not allow the clones to be distinguished from each other. Long pepper leaf explants, inoculated with strain R1601, formed roots that showed growth in subsequent subcultures.Keywords -Piper hispidinervium, root culture, second metabolites, in vitro culture..