Época de coleta e ácido indolbutírico no enraizamento de estacas de espirradeira (Nerium oleander L.)

A espirradeira (Nerium oleander L.) é uma importante espécie arbórea ornamental, muito utilizada no meio urbano. É propagada por estacas, porém a porcentagem de enraizamento é baixa e não há estudos sobre fatores que influenciam nesse processo. Este trabalho teve, portanto, o objetivo de estudar o efeito da época de coleta e do ácido indolbutírico (AIB) no enraizamento de estacas de duas variedades de espirradeira (Nerium oleander L.), determinadas pela coloração das flores (rosa e branca). O experimento foi instalado na UNESP, Campus de Jaboticabal/SP, no verão e no inverno. O delineamento experimental foi em blocos casualizados em esquema fatorial 2 x 2 x 4 (duas variedades combinadas com duas estações do ano e quatro concentrações de AIB - 0, 1.000, 2.000 e 4.000 mg kg-1). As avaliações foram realizadas 60 dias após a estaquia, sendo estas as variáveis: porcentagem de enraizamento, número médio, comprimento e massa de matéria seca de raízes. Concluiu-se que o enraizamento de ambas as variedades de espirradeira (rosa e branca) foi superior no verão. A variedade de flores rosas apresentou maior número e comprimento médio de raízes no verão, porém as maiores porcentagens de enraizamento e massa de matéria seca de raízes foram encontradas no inverno. O ácido indolbutírico foi efetivo para aumentar a porcentagem de enraizamento nas concentrações testadas de 1.000 e 2.000 mg kg-1; maior número, comprimento e massa de matéria seca de raízes foram obtidos na concentração de 2.000 mg kg-1.

Influence of hydric stress in the production of toxic principles in Nerium oleander L.

Many plants utilized in the urban center shows substances considered toxic whose production could be influenced by some factors, like hydric stress, including ornamental Nerium oleander L., widely used in gardens in various parts of the world, which presents production of cardioative glucosides, considered toxic. This study had the objective to evaluate the effect of field capacity in the biomass and the level of cardioative glucosides in seedlings of Nerium oleander. The experiment was carried at UNIDERP, in Campo Grande City, Mato Grosso do Sul State, Brazil, at the University for Development of State and Pantanal Region, using the experimental delineation in randomized blocks. There were 4 treatments (25%; 50%; 75% and 100% of the field capacity), 5 replications and 4 plants by parcel, totalling 80 plants. The evaluations were realized 60 days after the seedlings were planted. The quantitative analysis of the cardioative glucosides was realized by gravimetric test, after selective extraction of the glucosides. Were conclude that increase of the quantity of water in the soil raised the biomass production until 75% of the field capacity and increased the level of cardioative glucosides, showing that water management is very important and should be provided only the necessary to development of the plant.

Intoxicação experimental de cães com folhas verdes de Nerium oleander e uso da frutose 1,6 difosfato e da glicose como tratamentos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Atividade inseticida e Modos de Ação de Extratos Vegetais Sobre Mosca Branca (Bemisia tabaci)

Insecticide potential and efficaciousness of vegetal extracts concentrations from six botanic families in three different modes were analyzed on the nymphs of the silverleaf whitefly Bemisia tabaci (Genn. 1889) on a tomato plantation Lycopersicon esculentum Mill. Nymph breeding was kept in cherry tomato shrubs. Test solutions were obtained from successive extractions with ethanol and evaporation in a rotary evaporator. Tests consisted of 10 solutions in four concentrations (500; 1,000; 1,500 and 3,000 μg/mL) and control treatment (distilled water + 1% DMSO) under three different modes of activity, namely, contact, translaminar and systemic. Experimental design was totally randomized with four repetitions and eleven treatments. Means were compared by Scott-Knott test at 5% probability and lethal concentrations (CL50) were calculated by POLO. In the case of contact activity mode, all extracts had efficiency above 50% with the highest concentration (3,000 μg/mL) in which the highest efficiency for all extracts tested was verified. There was a need for dose increase in translaminar activity mode for similar results, whereas in the case of systemic activity the best performance was obtained with extracts of Nerium oleander, Derris amazonica and Ipomoea carnea. Extracts of the last two caused a higher percentage when compared with that of other extracts in all activity modes lower than CL50.

False positivity of gamma-glutamyl transpeptidase measurement in urine

Although enzymuria tends to be associated to renal injury, there are no studies that have evaluated the presence of the enzyme gamma-glutamyl transpeptidase (GGT) spectrophotometry in the urine using a non-nephrotoxic agent (Nerium oleander) in order to evaluate the possibility of false positive results. The urinary GGT/urinary creatinine concentration ratio (uGGT/uCr) of 10 healthy dogs was calculated and posteriorly confronted with data from clinical evaluation, hematological and serum biochemical profiles, creatinine clearance (CrC), urinalysis, urine protein/creatinine ratio (UPC), electrocardiogram, systemic blood pressure (SBP) and light and electron microscopy. The results for kidney histology, SBP, UPC and CrC were not significantly different in any of the time-points analyzed. However, uGGT/uCr was significantly higher when measured 4 hours and 24 hours after administration of N. oleander. The measurement of the urinary GGT enzyme, as performed in many studies, yielded false positive results in dogs poisoned by a non-nephrotoxic agent.