Tâmara Prado de Morais

Fontes e proporção de material orgânico para a produção de mudas de cafeeiro em tubetes

Neste trabalho, objetivou-se avaliar a qualidade das mudas de cafeeiro (Coffea arabica L.) produzidas em tubetes com substrato artificial suplementado com fontes de material orgânico em diferentes proporcoes. O experimento foi conduzido sob delineamento experimental de blocos casualizados em esquema fatorial 3 x 6, com quatro repeticoes em parcelas formadas por seis tubetes. O primeiro fator correspondeu as fontes de material orgânico (esterco bovino, humus de minhoca e cama de peru) e o segundo, suas proporcoes (0, 20, 40, 60, 80 e 100%) no substrato artificial (BioPlant-cafe) fertilizado com osmocote® (NPK 15-09-12). As caracteristicas avaliadas foram: altura da muda, diâmetro de caule, numero de pares de folhas, area foliar e massa seca da parte aerea e do sistema radicular. Pode-se concluir que o humus de minhoca adicionado ao substrato artificial na proporcao de 80% ou em uso exclusivo (100%) aumentou a area foliar das mudas de cafeeiro e, como consequencia proporcionou um maior acumulo de massa seca da parte aerea. O uso de esterco bovino (acima de 30%) e a cama de peru nao alterou ou reduziu as caracteristicas vegetativas das mudas de cafeeiro (altura da muda, diâmetro de caule, numero de pares de folhas e area foliar) e diminuiu o acumulo de massa seca.

Inoculation of maize with Azospirillum brasilense in the seed furrow

Several studies addressing the inoculation of cereals with diazotrophic microorganisms can be found in the literature. However, in many experiments, investigators have overlooked the feasibility of applying these microorganisms to the furrow together with the seed, and the effect of bacterial concentration on phytostimulation. The aim of this work was to evaluate the effect of doses of an inoculant based on Azospirillum brasilense, applied to the seed furrow when planting maize, combined with different doses of nitrogen fertiliser. The experiment was carried out in the field, in soil of the cerrado region of Brazil. An experimental design of randomised blocks in bands was adopted, comprising nitrogen (40, 100, 200 and 300 kg ha-1) and doses of an A. brasilense-based liquid inoculant applied to the seed furrow (0, 100, 200, 300 and 400 mL ha-1). The dose of 200 mL ha-1Azospirillum was noteworthy for grain production. This is the first report of the effective application of Azospirillum in the seed furrow when planting maize in the cerrado region of Brazil.

Biotecnologia aplicada ao melhoramento genético do cafeeiro

Genetic improvement of coffee through classical breeding is laborious and time consuming. Biotechnology offers alternative strategies to assist multiplication and development of new and improved coffee varieties, including those resistant to biotic and abiotic stresses, with better cup quality, and with uniform fruit maturation. Tissue culture techniques have enabled the production of a large number of plants with genetic uniformity. The use of molecular markers, especially through assisted selection, led to rapid progress of coffee plant breeding, as well as the use of genetic transformation by protoplasts culture and fusion, biobalistics, or Agrobacterium-mediated. This review provides a summary of biotechnology history, current situation and directions applied to the genetic improvement of coffee plant.

Aplicações da cultura de tecidos vegetais em fruteiras do Cerrado

Currently, its been given a huge concern to the cerrado plants, focusing on fruit trees due to their characteristics and uses. Despite being a fairly unexplored area, the number of studies on these native species has increased, especially those involving tissue culture techniques. Thats because this biotechnological tool provides the propagation of species with germination difficulty, reduces problems of recalcitrant seeds, promotes large scale seedling production, complements germplasm banks and facilitates the exchange of genetic materials. Therefore, this review summarizes the history and current situation of tissue culture techniques applied to Brazilian Cerrado fruit trees, providing support to further studies.

Aspectos morfofisiológicos de plantas de milho e bioquímico do solo em resposta à adubação nitrogenada e à inoculação com Azospirillum brasilense

Nitrogen (N) is a macronutrient that positively affects grain yields in maize crops, being its appropriate management indispensable for a sustainable agriculture, including the use of alternative resources such as diazotrophic bacteria. The aims of this work were to evaluate morphophysiological aspects of maize plants and activity of soil enzymes (urease and fosfatase) due to mineral N fertilization and Azospirillum brasilense inoculation. Two trials were conducted under greenhouse conditions with cerrado soil. A randomized block design was set up with treatments distributed as a 3 x 3 factorial. The first factor corresponded to N rates (0; 100 and 200 kg ha-1) and the second factor to an A. brasilense inoculant (0; 100 and 200 mL ha-1). At the end of this experiment, another trial was done to determine the possible residual effect of inoculation and nitrogen fertilization. Nitrogen application promoted maize plants growth, and increased chlorophyll and nutrient contents. Intensified activity of rhizosphere enzymes related to ammonium and inorganic phosphorus availability was also observed. In addition, N fertilization had residual effect on plant development in the test evaluating the residual effect of the fertilizer. The combination of 200 mL ha-1 of A. brasilense with 200 kg ha-1 of N increased the physiological response of the maize crop.

Aplicações da cultura de tecidos em plantas medicinais

The aim of this literature review is to conduct a survey concerning the history and current situation of tissue culture techniques in medicinal plants. Therefore, a review was done considering the period from 1976 to 2009. Tissue culture is widely applied in medicinal plants researches, especially micropropagation. The perspectives of tissue culture techniques in medicinal plants are related to the development of competitive germoplasm adapted to diverse methods of cultivation, the election of new species that will serve as source of biological active composts, and the improvement of phytochemicals production, in order to assure sustainable exploration of these species.

Inoculation of maize withAzospirillum brasilensein the seed furrow

Several studies addressing the inoculation of cereals with diazotrophic microorganisms can be found in the literature. However, in many experiments, investigators have overlooked the feasibility of applying these microorganisms to the furrow together with the seed, and the effect of bacterial concentration on phytostimulation. The aim of this work was to evaluate the effect of doses of an inoculant based on Azospirillum brasilense, applied to the seed furrow when planting maize, combined with different doses of nitrogen fertiliser. The experiment was carried out in the field, in soil of the cerrado region of Brazil. An experimental design of randomised blocks in bands was adopted, comprising nitrogen (40, 100, 200 and 300 kg ha-1) and doses of an A. brasilense-based liquid inoculant applied to the seed furrow (0, 100, 200, 300 and 400 mL ha-1). The dose of 200 mL ha-1Azospirillum was noteworthy for grain production. This is the first report of the effective application of Azospirillum in the seed furrow when planting maize in the cerrado region of Brazil.

Reguladores de crescimento vegetal no cultivo in vitro de Mentha x Piperita L.

Micropropagation is a technique used for the large-scale production of medicinal plants. Among them, peppermint (Mentha x piperita L.) may be mentioned because of the pharmacological importance of its essential oil, which is used on the treatment of digestive and respiratory disorders. Studies are needed in order to optimize the micropropagation protocol of this species, especially concerning the culture medium, to ensure the in vitro mass clonal production and to enable the future extraction of the plant essential oil. Therefore, this work aimed to evaluate the effects of concentrations and combinations of different plant growth regulators on the in vitro morphogenesis of peppermint. Nodal segments from plantlets already established in vitro were used as explants and inoculated on MS medium supplemented with 0, 2.0 and 4.0 mg L-1 of BAP (6-benzylaminopurine), 0, 0.5 and 1.5 mg L-1 of NAA (naphthalene acetic acid) and 0; 0.5 and 1.0 mg L-1 of GA3 (gibberellic acid). The experiment was in a completely randomized design, set up as a 3x3x3 factorial design with eight replicates. We concluded that BAP increases the survival rate of in vitro inoculated nodal segments of M. x piperita. In addition, its combination with GA3 stimulates explants shooting. Those aspects, however, are not promoted by the addition of NAA into the culture medium. Also, the results indicate that, after in vitro multiplication, peppermint shoots must be transferred to another medium without plant growth regulators for shoot elongation. High concentrations of BAP promote calli induction, despite having beneficial effects on the organogenesis of M. piperita.

The PDB database is a rich source of alpha-helical anti-microbial peptides to combat disease causing pathogens

The therapeutic potential of α-helical anti-microbial peptides (AH-AMP) to combat pathogens is fast gaining prominence. Based on recently published open access software for characterizing α-helical peptides (PAGAL), we elucidate a search methodology (SCALPEL) that leverages the massive structural data pre-existing in the PDB database to obtain AH-AMPs belonging to the host proteome. We provide in vitro validation of SCALPEL on plant pathogens ( Xylella fastidiosa, Xanthomonas arboricola and Liberibacter crescens) by identifying AH-AMPs that mirror the function and properties of cecropin B, a well-studied AH-AMP. The identified peptides include a linear AH-AMP present within the existing structure of phosphoenolpyruvate carboxylase (PPC20), and an AH-AMP mimicing the properties of the two α-helices of cecropin B from chitinase (CHITI25). The minimum inhibitory concentration of these peptides are comparable to that of cecropin B, while anionic peptides used as control failed to show any inhibitory effect on these pathogens. Substitute therapies in place of conventional chemotherapies using membrane permeabilizing peptides like these might also prove effective to target cancer cells. The use of native structures from the same organism could possibly ensure that administration of such peptides will be better tolerated and not elicit an adverse immune response. We suggest a similar approach to target Ebola epitopes, enumerated using PAGAL recently, by selecting suitable peptides from the human proteome, especially in wake of recent reports of cationic amphiphiles inhibiting virus entry and infection.