INTRODUÇÃOA melissa (Melissa officinalis L.), conhecida como erva-cidreira verdadeira pertence à família Lamiaceae, é de origem asiática e europeia e foi Recebido para publicação em 22/10/2010 Aceito para publicação em 17/08/2011 Palavras-chave: planta medicinal, metabólito secundário, produção, intensidade luminosaABSTRACT: Growth, biomass production and essential oil content of lemon balm (Melissa officinalis L.) under different shading levels. The aim of this study was to evaluate the variation in essential oil content, growth and biomass production of Melissa officinalis L. cultivated under different shading levels. Experimental design was completely randomized (CRD) with four levels of photosynthetically active radiation (PAR), full light (control) and progressive shading with shade net (shading of 75, 50 and 25%) and six replicates. The following parameters were assessed: stem diameter, plant height, fresh mass and dry mass of shoot, essential oil content, essential oil yield and leaf area. Data were subjected to analysis of variance and regression analysis at 1 and 5% error probability. The characteristics stem diameter and plant height did not show significant differences among treatments. Production of fresh weight, dry mass and essential oil content was similar among all treatments, except for full light, where (FW): 25%=50%, 91.33 g and 68.66 g; (DW): 25%=0%=50%, 11.35, 11.66, 10.66 g and 4.33 g and OC: 25%=50%, 0.48 and 0.40% respectively. The treatment that resulted in the lowest productivity was 75% shading. Thus, in the north of Minas Gerais State, Brazil, from February to June, lemon balm can be cultivated under conditions of up to 50% shading, favoring the production of dry mass, fresh mass and essential oil content; these variables are of commercial interest for producers of medicinal and aromatic plants.Key words: medicinal plant, secondary metabolite, production, light intensity introduzida no Brasil há mais de um século, sendo atualmente cultivada em todo o país. Toda a planta exala odor semelhante ao do limão, que se torna maisRev.

RESUMO O objetivo deste estudo foi avaliar a produção de fi tomassa e óleo essencial da M. offi cinalis L. com lâminas de irrigação no Norte de Minas Gerais como medidas de uso racional da água. O delineamento experimental utilizado foi o inteiramente ao acaso em parcelas subdivididas no tempo, com seis tratamentos defi nidos pelas lâminas de irrigação (T1=0,50xET0; T2=0,75xET0; T3=1,0xET0; T4=1,25xET0; T5=1,5xET0 e T6=1,75xETO) ABSTRACT The objective of this study has been to evaluate the essential oil production of Melissa offi cinalis L. with irrigation blade in the North of Minas Gerais as a measure of water rational use. The experimental design has been completely randomized in subdivided plots in the time with six treatments, defi ned by irrigation blade (T1=0,50xET0; T2=0,75xET0; T3=1,0xET0; T4=1,25xET0; T5=1,5xET0 e T6=1,75 x ETO), and four replications. The study has been conducted at the micro lysimeter. Based on regression analysis, it has been observed that the fi tomass production and growth was infl uenced by water availability. The production and content of the essential oil are inversely proportional to the increase in the irrigation blade. The production of biomass has been obtained from the smaller blade and the evaluation times did not infl uenciate on their blades.

ResumoO objetivo deste trabalho foi avaliar o crescimento e teor de óleo essencial de Melissa of¿ cinalis nas condições climáticas de Montes Claros -MG. O experimento foi conduzido de maio a novembro de 2009. O delineamento experimental foi o inteiramente casualizado (DIC) com quatro tratamentos e cinco repetições. Na primeira análise, foi avaliado o efeito da época de colheita sobre a produção de biomassa e óleo essencial. Na segunda análise, foi avaliada a produção de biomassa e óleo essencial após 30 dias da colheita da análise anterior. Os dados foram submetidos à análise de regressão, utilizando o software SAEG. Dos resultados encontrados, o primeiro corte aos 33 dias favoreceu a produção de massa seca. A melhor época de produção de óleo essencial em melissa ocorreu na rebrota 30 dias após o primeiro corte da planta mais jovem. Com este trabalho concluiuse que a colh eita mais precoce nas condições do Norte de Minas favorece a produção de biomassa e apresenta teor de óleo essencial similar às demais colheitas. Palavras-chave: Biomassa, Metabólitos secundários, Plantas medicinais AbstractGrowth and production of essential oil of Lemon Balm (Melissa of¿ cinalis L.). The objective of this study was to evaluate the growth and essential oil production of Melissa of¿ cinalis in the climatic conditions of Montes Claros -MG. The experiment was conducted from May to November 2009. The experimental design was completely randomized (CRD) with four treatments and ¿ ve repetitions. In the ¿ rst analysis, the effect of harvesting time on the biomass and essential oil was evaluated. In the second analysis, the production of biomass and essential oil after 30 days of harvest of the previous study was evaluated. The data were submitted to regression analysis using the software SAEG. From the results, the ¿ rst cut at 33 days, increased the percentage of dry matter, and the best time of production of the Lemon Balm's essential oil occurred during regrowth, 30 days after the ¿ rst harvest of the younger plant. This study concluded that the early harvest in the conditions of northern Minas Gerais favors the production of biomass and feature content of essential oil similar to other crops.

RESUMOObjetivou-se caracterizar a população de Stryphnodendron adstringens (Mart.) Coville para verificar a viabilidade de manejo em uma área de cerrado sensu stricto no norte de Minas Gerais. Para isso, inventariaram-se 25 parcelas, de 400 m² cada uma, em dois sítios (I e II), totalizando 1 hectare amostrado em cada sítio. Foram mensurados todos os indivíduos adultos vivos de barbatimão com diâmetros a 1,30 m do solo (DAP) ≥ 3 cm de barbatimão. Dentro das parcelas foram mensurados o diâmetro (DAP) e a altura (H) e, posteriormente, para cada sítio foram avaliados: o quociente de De Liocourt (q), a área basal (G) e a estratificação vertical. Os resultados mostraram uma densidade de 180 e 218 indivíduos/ ha, diâmetros médio de 7,38 e 6,26 cm, média de 'q' de 2,22 e 1,50 e alturas médias de 2,93 e 3,10 m nos dois sítios respectivamente. O quociente de De Liocourt mostrou comprometimento no recrutamento em algumas classes diamétricas no Sítio II. Apesar do desbalanceamento apontado pelo valor 'q', a distribuição diamétrica comportou-se de forma exponencialmente negativa conforme o esperado para florestas nativas em processo de sucessão secundária. Observou-se uma maior concentração de indivíduos no estrato médio de altura com 142 e 154 indivíduos em cada sítio respectivamente. Conclui-se que, embora tenham estruturas distintas, nos dois sítios estudados, as populações de barbatimão são compostas por um grande número de indivíduos de pequenos diâmetros e com exclusividade do estrato vertical mediano. A capacidade de regeneração da espécie, alta densidade de indivíduos por hectare e a estrutura horizontal e vertical mostram que existe viabilidade em manejar o barbatimão no dois sítios desde que suas estruturas sejam mantidas equilibradas. Palavras-chave: estrutura horizontal; estrutura vertical; viabilidade de manejo; inventário florestal. ABSTRACTThis study aimed to characterize of the Stryphnodendron adstringens (Mart.) Coville population to verify the viability of sustainable management in area of Savanna in the north of state Minas Gerais, Brazil country. Therefore inventoried 25 plots of 400 square meters in two places, in all was inventoried one

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The characterization and selection of molecular markers are important for genetic pre-breeding programs since they make it possible to choose the most appropriate markers to be used in future research. Therefore, enabling the generation of subsidies for genetic-molecular studies in algabora (Prosopis juliflora (Sw.) DC). The amplification profile was characterized. It was generated from 17 pairs of RGA primers (Resistance Gene Analogs) in 20 samples of genomic DNA of P. juliflora extracted from specimens collected in the city of Itapetinga, Bahia. The amplifications were performed according to previously published laboratory routines and the amplification profiles analyzed from the photodocumentation of the electrophoresis results in 2% agarose gels. Based on the amplification profiles the primer pairs were classified as: Suitable: amplifications in the whole samples and with easy visualization; Reasonable: amplification in parts of the samples and/or difficult to visualize or Inadequate: absence of visible amplification products. Descriptive analyzes associated with the number of generated markers, percentage of polymorphism, expected heterozygosity (He) and the content of polymorphic information (PIC) were also performed. In a nutshell, 12 out of the 17 pairs of RGA primers generated amplification products with easy visualization and only two of these 12 pairs of primers were monomorphic. The percentage of polymorphism varied from 60% to 100%, He and PIC presented an average of 0.21 (ranging from 0 to 0.38) and 0.17 (ranging from 0 to 0.29), respectively. The results confirm that the RGA primers present adequate characteristics for genetic studies in P. juliflora, making it possible to prioritize 12 pairs of primers, which are subject to genetic improvement studies.

Brazil is highlighted as the largest producer and consumer of passion fruit (Passiflora) and holder of representative biodiversity. Studies dedicated to the genetic characterization of the genus in order to understand the existing diversity are important for the advancement of genetic improvement and conservation programs. The aim of this study was to select combinations of RGA (Resistance Genes Analogs) primers for commercial passion fruit species and varieties. To this end, amplification tests were performed on a PCR platform in 17 combinations of RGA primers for eight species and 12 commercial varieties of passion fruit from the Banco Ativo de Germoplasma Flor da Paixão. All combinations of primers have generated amplification products in at least one of the Passiflora samples. The number of combinations that generated amplification products varied from seven to 12 in the species and from three to eight in the varieties. Three to 12 combinations generated amplification products for the samples, emphasizing that the RGA markers were efficient in accessing genomic loci in the species and varieties of passion fruit. The variation of efficient combinations in each of the species and varieties attested to the importance of this research in the preliminary stages of genetic studies as auxiliary tools in conservation and genetic improvement programs. However, this study made it possible to identify combinations of primers to be prioritized in inter and intraspecific genetic characterizations of passion fruit.

RESUMENEste estudio tuvo como objetivo evaluar las estimaciones de volumen y altura para el barbatimão con el fin de generar ecuaciones, que se puedan utilizar en la preparación de planes de gestión sostenible de esta especie, a partir de modelos para así estimar el volumen total con corteza, sin corteza y de la corteza, y también las relaciones hipsométricas. Se comparó también la producción de corteza en las diferentes clases diamétricas. Un inventario forestal ejecutado posibilitó la realización de la cubicación rigurosa de 100 árboles, separados en ocho clases diamétricas por el método de Huber. Se probaron 16 modelos volumétricos de entrada simple y doble, y 6 de relaciones hipsométricas. Los modelos que mejor se ajustaron fueron el de Husch y Spurr en su forma logaritmizada para las estimaciones de volumen y el de Stofel para las estimaciones de altura. Respecto a la proporción de corteza se ha encontrado un mayor porcentaje en los especímenes de las menores clases diamétricas.Palabras-clave: modelos volumétricos, Cerrado stricto sensu, cubicación rigurosa, corteza. Barbatimão Volumetrics and Hypsometrics Estimates in Northern Minas Gerais ABSTRACTThis study sought to assess the barbatimão volume and height estimates generating equations that can be used in the preparation of sustainable management plans from models to estimate the total volume with bark, without bark, of the bark as well as hypsometric relations. The production of bark in the various diameter classes was also compared. A forest inventory was conducted and generated the rigorous cubage of 100 separate trees in eight diameter classes by the method of Huber and tested 16 models of volumetric single and double entry and six of hypsometric relations. The best fit models were the Husch and Spurr in logarithmic form and the best height model was Stofel. Regarding the bark proportion it was found a higher percentage in individuals with the lowest diameter classes.