Márcia Vaz Ribeiro

Produção de betacianina em erva-de-jacaré cultivada in vitro com diferentes concentrações de sulfato de cobre

The manipulation of concentration of trace elements in the culture medium represents a good strategy to increase the production of secondary metabolites in tissue culture. This study aimed to demonstrate the influence of copper sulphate in the production of betacyanin and the multiplication of plants of Alternanthera philoxeroides (alligator weed) cultured in vitro. Nodal segments, obtained from plants pre-stablished and after three subcultures, were inoculated in basic MS with different concentrations of CuSO4 (0, 25, 75, 125, 175, 200µM). The results were subjected to analysis of variance, polynomial regression and correlation analysis between the morphological variables and the production of betacyanin. The experimental design was completely randomized with six concentration of CuSO4 and five replicates represented by a bottle containing four explants. Concentrations above 75µM decreased the height of the plant, number of shoots and buds and root growth, while the concentration of 125µM resulted in the highest fresh mass production. Betacyanin production increased 60% over control with 175µM CuSO4. Plant growth occurred in all tested concentrations of CuSO4, with the exception of 200µM which was toxic.

Análise multivariada da divergência genética de genótipos de arroz sob estresse salino durante a fase vegetativa

Soil salinity is a limiting factor for rice cultivation, especially in the early stages of development and the flowering period. The use of sources of poor quality water for irrigation results in the accumulation of salts in the soil, causing major toxicity in culture. A solution to the problem would be the introduction of varieties with tolerance to high salinity. Hus the aim of this work is to evaluate genetic divergence among rice genotypes, aiming at the selection of genotypes tolerant to salinity during the vegetative phase. Seeds of 10 rice genotypes were grown in vitro on MS medium supplemented with 0 and 136 mM NaCl. After 21 days, six morphological characters were evaluated and the results subjected to multivariate analysis. The methods of Tocher, based on Mahalanobis distance, and graphic dispersion of canonic variables followed the same pattern of clustering structure, forming six groups. The characteristic of shoot fresh weight was the largest contributor to the genetic dissimilarity between genotypes by the method of Singh, while the other two canonic variables were sufficient to account for 91.27% of observed variation. Under the experimental conditions tested, the genotypes showed different degrees of salinity tolerance, while Colossus BRS, BRS Bojuru and BR IRGA 410, belonging to the groups three and four, were those who were more tolerant genotype and Moti, belonging to two what was more sensitive to salt stress.

Variabilidade em matrizes de acessos de espinheira-santa

Maytenus ilicifolia and M. aquifolium are native Brazilian species popularly known as espinheira-santa, being indicated for gastritis and stomach ulcer. Embrapa Clima Temperado and Universidade Federal de Pelotas (UFPel) keep a gene bank of these species. With the objective of identifing phenotypic variability for some morphological characters in matrices of espinheira-santa, estimating dissimilarity and clustering accessions through multivariate analysis, 105 accessions had been morphologically characterized. The characteristics evaluated were fruit length, fruit width, number of seeds per fruit, leaf length, leaf width, leaf length/leaf width ratio and number of thorns per leaf. The euclidean distance was estimated and accessions were clustered by Tocher optimization method. A wide variability for all the characteristics analyzed was observed. The number of thorns per leaf was the characteristics that more contributed to the divergence. The morphological characteristics enabled to separate the accesses in seven clusters. The higher dissimilarity was between accessions 57 (M. ilicifolia) and 91 (M. aquifolium). There was no evidence of a separation in accordance to the geographic localization of the accessions. In the clustering analysis were identified two clusters that had accessions of both species, M. ilicifolia and M. aquifolium, indicating phylogenetic relatedness between these species.

Diversidade genética entre acessos de espinheira-santa (Maytenus ilicifolia Mart. ex Reis.) coletados no estado do Rio Grande do Sul, Brasil

Maytenus ilicifolia Mart. ex Reis., popularmente conhecida como espinheira-santa, e especie autoctone pertencente a familia Celastraceae, usada para tratamento de ulceras gastricas e gastrites. Devido a importância medicinal, houve aumento no extrativismo das populacoes naturais, tornando-a uma especie prioritaria para a conservacao, a fim de evitar a erosao genetica. Buscou-se com este trabalho analisar a diversidade genetica de 20 acessos de M. ilicifolia coletados em diferentes localidades no Rio Grande do Sul. Utilizando marcadores moleculares do tipo AFLP, foram testadas oito combinacoes de primers, que geraram 455 bandas eletroforeticas, 100% polimorficas. As combinacoes de primers E-ACC/M-CAA, E-ACG/M-CTA, E-ACG/M-CTC apresentaram o maior numero de bandas eletroforeticas, 71 cada, totalizando 46,80% do polimorfismo total. Os valores de similaridade genetica calculada pelo coeficiente simple matching foram utilizados para gerar o dendrograma de similaridade pelo metodo UPGMA. Foi obtido alto coeficiente de correlacao cofenetica (r=0,94), demonstrando elevada representatividade dos dados de similaridade genetica no dendrograma. Pela AMOVA verificou-se que 89,33% da diversidade total ocorreram entre individuos dentro das populacoes. A caracterizacao molecular de acessos de Maytenus ilicifolia por meio de AFLP foi eficiente para identificar diversidade genetica. Atraves da analise de similaridade genetica o banco de germoplasma poderia ser composto com os acessos que apresentaram menor similaridade e maior numero de alelos, permitindo com que estes fornecessem ampla cobertura do genoma que compoem Maytenus ilicifolia. Os acessos que ficaram agrupados em mesmo cluster e com numero reduzido de alelos podem ser descartados deste banco. A diversidade genetica intrapopulacional identificada por esse marcador foi muito maior do que aquela entre populacoes.

Pigment production and growth of Alternanthera plants cultured in vitro in the presence of tyrosine

The aim of the present study was to investigate the influence of tyrosine on the in vitro growth and the production of the betacyanin pigment in Alternanthera philoxeroides and A. tenella. Nodal segments were inoculated in MS medium containing different concentrations of tyrosine (0, 25, 50 and 75 μM), and the number of sprouts and buds, height, root length, fresh matter of shoots and roots and betacyanin content were evaluated. In A. philoxeroides , the highest production of betacyanin (51.30 mg 100 g-1 FM) was in the stems with the addition of approximately 45 μM tyrosine, while the increase in the leaves was proportional to the tyrosine concentration, and the best average was obtained with a tyrosine concentration of 75 μM (15.32 mg 100 g-1 FM). Higher tyrosine concentrations were deleterious to the growth of A. tenella plants, and a concentration of 75 μM was considered toxic. However, a tyrosine concentration of 50 μM benefitted betacyanin production, which reached 36.5 mg 100 g-1 FM in the plant shoots. These results showed the positive effect of tyrosine on the production of betacyanin in both species; however, application at high concentrations hampered the growth of Alternanthera plants.

Espinheira-santa (Maytenus ilicifolia Mart. ex Reiss.): saber de erveiros e feirantes em Pelotas (RS)

The aim of this study was to describe the popular knowledge related to the espinheira-santa (Maytenus ilicifolia) among herbalists and marketers that sell this plant in the center of Pelotas/Rio Grande do Sul State, Brazil. A qualitative, exploratory and descriptive research was performed between August and July of 2013. Semi-structured interviews, with questions regarding the knowledge and practices related to this plant, were applied to five herbalists and three marketers inserted in the informal market of medicinal plants. The operative proposal by Minayo was used in order to analyze the data, and the theoretical framework by Capra was used in the discussion. The popular knowledge related to the use of espinheira-santa is passed on from generation to generation, although nowadays there are other sources ofinformation. The popular clueswith therapeutic purposes are related to gastric disorders, healing and blood clearance. The study participants have different forms of interaction with the environment, the family and other interpersonal relationships, resulting in different popular knowledges related to this medicinal plant.