7 resultados para Plantas - Resistencia a doenças e pragas
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The currently main development model on global society is driven by an economic rationality that endangers the environment and social justice. More and more, attention to this way of production and consumption is increasing, boosting research for sustainable development, with an environmental rationality that can harmonize nature preservation and welfare of all socioeconomic classes. One of the efforts on this sense is changing the sources supplying the energy demand, replacing fossil fuels for renewable and cleaner sources, such as biofuels. Carthamus tinctorius (safflower) is an oilseed crop with potential for biodiesel production, with good oil yield and chemical profile, allied to good adaptation to climates such like the northeastern semiarid lands of Brazil. With public policies fomentation, the use of this species may be an interesting alternative for family farming. In farming in general, the use of pesticides to prevent and combat diseases and plagues is common, which is not a sustainable practice. Thus, there are researched alternative, less dangerous substances. In this study, it was aimed to assess if neem (Azadirachta indica) leaf extract (20% m/v) and Bordeaux mixture (copper sulfate) have effects on safflower. It was also aimed to verify acceptance of farmers on safflower crop in Apodi, a municipality in Rio Grande do Norte state, Brazil, in view of it being localized in the aimed region for this crop cultivation. Besides that, understanding that the farmers’ knowledge and inclination to adopt the crop is fundamental for the introduction of this species and socioeconomic growth due to its exploration. In addition, a booklet with basic information on safflower was produced. In the field experiment, the fungicides were pulverized on plants cultivated in field experimental plots, with collection of leaf samples for analysis on anatomy, cuticle, and epicuticular wax morphology, the protective layer that interfaces with the surrounding ambient. In Apodi, forty-five farmers from Potiguar Cooperative of Apiculture and Sustainable Rural Development (COOPAPI) underwent semi-structured interviews, which also addressed their assessment on currently cultivated crops and perception of pesticide uses and sustainable alternatives. After comparing using analysis of variance, it was found that there was no difference between treatments in the experiment, as well as no anatomical or morphological modifications. Safflower acceptation among farmers was wide, with 84% of interviewees believing in a perspective of good incomes. The current scenario, comprised of low crop diversity, fragile in face of droughts and plagues, can partially explain this opinion. The booklet was effective in catching people attention for the species potential. There was wide acknowledgement on the importance of alternative pesticides, justified by health security. Based on the assessed parameter in the results of this research, the treatments here utilized may be recommended as fungicides for safflower. Given the crop susceptibility to fungi in heavy rainy period, it is advised that its potential introduction on the region shall be focused on semiarid areas.
Resumo:
This paper aims to describe the familiar cotton culture in the districts of Tangará and Triunfo Potiguar, located in the state of Rio Grande do Norte. It relates specific problems that small cotton agriculturists face in the cotton production and sale as well as their perception in relation to public policies that have been put into practice in these districts. The research revealed soils with potentiality for the cotton culture, but that are not being cultivated for anything else but subsistence, not being able to become productive, specifically through the cotton culture. That activity should be practiced so that it preserves the environment and the familiar farmers themselves, since it was verified they are constant1y exposed to health problems due to insecticides use. In what refers to fomentation policies it was observed that bureaucracy delays the liberation of the money destined to production, seeds delivery and other actions related to production and commercialization. Some procedures such as information and training about productivity development and attention with the environrnent and infrastructure are recommended. The results indicate lack of investments, rural credit and technical help, main1y in Triunfo Potiguar. There is unanimity, from the rural farmers of that district in what refers to the desire of improving the production and remaining in that activity. In this sense, the contribution of this research for the most appropriate culture production can be materialized through the technique of tissue's culture, aimed at obtaining plants that are resistant to diseases. The data indicated that the hormonal supplementations used induced regenerative calluses making in vitro morphogenesis possible in alI tested varieties. The use of the activated coal antioxidant was efficient, reducing oxidation, however not suppressing it. The results lead to an opportunity for the familiar tàrmers from Rio Grande do Norte enlarge the cotton culture, because to obtain plants that are resistant to diseases implies in insecticides reduction, propitiating smaller impact to the atmosphere and less cost
Resumo:
The inefficiency of chemical pesticides to control phytopathogenic fungi in agriculture and the frequent incidence of human diseases caused by bacteria which are resistant to antibiotics lead to the search for alternative antimicrobial compounds. In this context, plant defensins are a promising tool for the control of both plant and human pathogenic agents. Plant defensins are cationic peptides of about 50 amino acid residues, rich in cysteine and whose tridimensional structure is considerably conserved among different plant species. These antimicrobial molecules represent an important innate component from plant defense response against pathogens and are expressed in various plant tissues, such as leaves, tubers, flowers, pods and seeds. The present work aimed at the evaluation of the antimicrobial activity of two plant defensins against different phytopathogenic fungi and pathogenic bacteria to humans. The defensin Drr230a, whose gene was isolated from pea (Pisum sativum), and the defensin CD1,whose gene was identified within coffee (Coffea arabica) transcriptome, were subcloned in yeast expression vector and expressed in Pichia pastoris. The gene cd1 was subcloned as two different recombinant forms: CD1tC, containing a six-histidine sequence (6xHis) at the peptide C-terminal region and CD1tN, containing 6xHis coding sequence at the N-terminal region. In the case of the defensin Drr230a, the 6xHis coding sequence was inserted only at the N-terminal region. Assays of the antimicrobial activity of the purified recombinant proteins rDrr230a and rCD1 against Phakopsora pachyrhizi, causal agent of soybean Asian rust, were performed to analyze the in vitro spore germination inhibition and disease severity caused by the fungus in planta. Both recombinant defensins were able to inhibit P. pachyrhizi uredospore germination, with no difference between the antimicrobial action of either CD1tC or CD1tN. Moreover, rDrr230a and rCD1 drastically reduced severity of soybean Asian rust, as demonstrated by in planta assays. In spite of the fact that rCD1 was not able to inhibit proliferation of the human pathogenic bacteria Staplylococcus aureus and Klebsiella pneumoniae, rCD1 was able to inhibit growth of the phytopathogenic fungus Fusarium tucumaniae, that causes soybean sudden death syndrome. The obtained results show that these plant defensins are useful candidates to be used in plant genetic engineering programs to control agriculture impacting fungal diseases.
Resumo:
Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae
Resumo:
Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Ceará. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity
Resumo:
Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae
Resumo:
Malaria, also popularly known as maleita , intermittent fever, paludism, impaludism, third fever or fourth fever, is an acute infectious febrile disease, which, in human beings, is caused by four species: Plasmodium falciparum, P. vivax, P. malariae and P. ovale. Malaria, one of the main infectious diseases in the world, is the most important parasitoses, with 250 million annual cases and more than 1 million deaths per year, mainly in children younger than live years of age. The prophylactic and therapeutic arsenal against malaria is quite restricted, since all the antimalarials currently in use have some limitation. Many plant species belonging to several families have been tested in vivo, using the murine experimental model Plasmodium berghei or in vitro against P. falciparum, and this search has been directed toward plants with antithermal, antimalarial or antiinflammatory properties used in popular Brazilian bolk medicine. Studies assessing the biological activity of medicinal plant essential oils have revealed activities of interest, such as insecticidal, spasmolytic and antiplasmodic action. It has also been scientifically established that around 60% of essential oils have antifungal properties and that 35% exhibit antibacterial properties. In our investigation, essential oils were obtained from the species Vanillosmopsis arborea, Lippia sidoides and Croton zethneri which are found in the bioregion of Araripe-Ceará. The chemical composition of these essential oils was partially characterized and the presence of monoterpenes and sesquiterpenes. The acute toxicity of these oils was assessed in healthy mice at different doses applied on a single day and on four consecutive days, and in vitro cytotoxicity in HeLa and Raw cell lines was determined at different concentrations. The in vivo tests obtained lethal dose values of 7,1 mg/Kg (doses administered on a single day) and 1,8 mg/Kg (doses administered over four days) for 50% of the animals. In the in vitro tests, the inhibitory concentration for 50% of cell growth in Hela cell lines was 588 μg/mL (essential oil from C. zethneri after 48 h), from 340-555 μg/mL (essential oil from L. sidoides, after 24 and 48 h). The essential oil from V. arborea showed no cytotoxicity and none of the essential oils were cytotoxic in Raw cell lines. These data suggest a moderate toxicity in the essential XVIII oils under study, a finding that does not impede their testing in in vivo antimalarial assays. Was shown the antimalarial activity of the essential oils in mice infected with P. berghei was assessed. The three species showed antimalarial activity from 36%-57% for the essential oil from the stem of V. arborea; from 32%-82% for the essential oil from the leaves of L. sidoides and from 40%-70% of reduction for the essential oil from the leaves of C. zethneri. This is the first study showing evidence of antimalarial activity with these species from northeast Brazil. Further studies to isolate the active ingredients of these oils are needed to determine if a single active ingredient accounts for the antimalarial activity or if a complex integration of all the compounds present occurs, a situation reflected in their biological activity