This work describes the chemical composition of the volatile oil of Hyptis marrubioides cultivated in field and greenhouse. The experimental design was completely randomized, with ten replications for each type of cultivation. The volatile oil was extracted by hydrodistillation and analyzed by GC-MS. The highest content of volatile oil was found for plants grown in field. The highest percentage of the compounds present in oils was observed in samples grown in the field, such as germacra-4(15),5,10(14)-trien-1-α-ol (16.34%), β-caryophyllene (10.42%), γ-muurolene (12.83%) and trans-thujone (9.98%). However, some compounds were found only in plants grown in a greenhouse, such as cis-muurol-5-en-4α-ol (10.84%), α-cadinol (3.06%) and eudesma-4(15),7-dien-1β-ol (6.82%).

A arnica é uma planta amplamente usada na medicina popular que sofre risco de extinção. Este trabalho objetivou avaliar o crescimento, teor e acúmulo de nutrientes e alumínio na parte aérea de arnica em resposta à calagem e adubação. O experimento foi conduzido em casa de vegetação, em amostra de Cambissolo álico, em esquema fatorial 2x3+1, sendo dois níveis de calagem (sem e com), três tipos de adubação (mineral, orgânica e mista). Para controle foi utilizado um tratamento adicional, constituído de solo proveniente da região endêmica da arnica, para simular suas condições naturais de desenvolvimento. Foram utilizadas quatro repetições e uma planta por vaso. Tomaram-se as alturas inicial e final, obtendo-se o crescimento relativo (CR) e determinaram-se as massas secas de parte aérea (MSPA) e de raiz (MSR). Foram determinados o teor e o acúmulo de nutrientes e alumínio na MSPA. De modo geral, a arnica apresentou maiores valores MSPA, MSR e CR com adubos minerais e menores com orgânico. Para MSPA, a calagem foi essencial somente nos tratamentos que receberam adubo orgânico. A arnica é uma planta tolerante ao Al, exigente em Zn e Mn e não exigente em macronutrientes.

Arnica is a plant widely used in folk medicine, which is in danger of extinction. This work aimed to evaluate growth, nutrients and aluminum contents and quantity in aboveground dry matter under liming and fertilization. The experiment was carried out in greenhouse, with allic Cambisol samples in 2x3+1 factorial scheme, using two liming levels (with and without) and three fertilization types (mineral, organic and mixed). Control was an additional treatment, using soil from arnica endemic land, to simulate its natural conditions of development. Four replications were used and one plant for each pot. Relative growth (RG) was obtained from initial and final heights. Aboveground dry matter (ADM) and the root dry matter (RDM) were determined. The contents and accumulation of nutrients and aluminum were determined in ADM. Generally, arnica showed higher ADM, RDM and RG with mineral fertilization and lower ADM, RDM and RG with organic fertilization. For ADM, liming was essential only in treatments with organic fertilizer. Arnica is not Al-tolerant, it is Zn- and Mn-exigent, but is not macronutrients-exigent plant.

Visando determinar um método para micropropagação a partir de bulbinhos in vitro, de cultivares de cebola (Allium cepa L.), foram realizados três experimentos, avaliando-se a influência do 6-benzilaminopurina (BAP) x ácido naftalenoacético (ANA) e posição do explante no meio de cultura, a influência de bulbinhos desenvolvidos em diversas concentrações de sacarose e o efeito do diâmetro dos bulbinhos sobre a taxa de multiplicação in vitro. Pelos resultados, a posição vertical dos explantes mostrou maior tendência para porcentagem de regeneração nos cultivares Pira Ouro e Pirana Precoce. 0 efeito das concentrações de fitorreguladores na porcentagem de regeneração não foi verificado para o 'Pira Ouro', enquanto para o 'Pirana Precoce', porcentagem mais elevada foi obtida em 4,0 mg/L de BAP x 0,5 mg/L de ANA. Maior taxa de multiplicação foi observada para os dois cultivares em BAP (2,0 mg/L) x ANA (0,25 mg/L). Bulbinhos do cultivar Pira Ouro e híbrido entre Pira Ouro e Pirana Precoce, desenvolvidos em 120 g/L de sacarose, mostraram-se mais adequados à micropropagação in vitro no material utilizado. Com relação ao diâmetro inicial do explante, o 'Pira Ouro' não mostrou diferença estatística para os parâmetros avaliados, enquanto no 'Pirana Precoce' maior porcentagem de regeneração foi obtida nos diâmetros M (5 a 10 mm) e P (< 5 mm), e maior número de brotos no diâmetro M.

Series of three different experiments were carried out, in order to study the optimization of the use of bulblets obtained in vitro, in the micropropagation of the onion (Allium cepa L.). Initially, it was evaluated the effects of the interaction between two doais of 6-benzylaminopurine (BAP) and naphthaleneacetic acid (NAA), and the position of the explant in the medium, for the cultivara Pira Ouro and Pirana Precoce. For 'Pira Ouro' the phytohormone concentrations did not affect the percentage of regeneration; however, for 'Pirana Precoce', the rates of 4.0 mg/L of BAP and 0.5 mg/L of NAA gave the best results. The highest multiplication rate, measured by the number of shoots obtained, for both cultivars, was observed with 2.0 mg/L of BAP and 0.25 mg/L of NAA. The vertical position of the explant showed a tendency of increasing the percentage of regeneration for the two genotypes. Explants from bulblets obtained with the sucrose concentration of 120 g/L were best fitted for the regeneration process, as showed by the second experiment, carried out with the Pira Ouro cultivar and the hybrid Pira Ouro x Pirana Precoce. The size of the bulblet, measured as its diameter, utilized as the source of the explants was studied in the third one, for the same cultivars utilized in the first experiment. For 'Pira Ouro', there was no influente, both, for the percentage of regeneration and the number of shoots obtained. The small diameter (P: < 5 mm) and the medium one (M: 5 a 10 mm), in the Pirana cultivar, had higher percentage of regeneration; the highest number of shoots was obtained with M diameter.