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Search Results: 1 - 10 of 17930 matches for " Eliana Gertrudes Macedo;Almeida "
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Molecular and Pathogenic Study of Guignardia spp. Isolates Associated to Different Hosts  [PDF]
Ester Wickert, Andressa de Souza, Rodrigo Matheus Pereira, Luciano Takeshi Kishi, Eliana Gertrudes de Macedo Lemos, Antonio de Goes
Advances in Microbiology (AiM) , 2014, DOI: 10.4236/aim.2014.42016
Abstract:

Fungi of Guignardia genus are commonly isolated from different plant species and most of the time, they are characterized as endophytes. However, some species of this genus, like G. citricarpa and G. psidii are known as causal agents of serious diseases that affect important crops such as Citrus Black Spot and guava fruit rot, respectively. They are also responsible for diseases that cause foliar spots in different fruit species and also in other crops, but cause minor damages. Despite evidences that G. mangiferae colonizes different plant species, there are few studies about its genetic diversity associated with different hosts. This work has the objective to characterize Guignardia isolates obtained from different hosts and tissues by RAPD, fAFLP and DNA sequence of ITS1-5.8S-ITS2 region, as well as to develop pathogenicity tests through cross inoculation in citrus and guava fruits. It was observed that molecular markers were able to discriminate isolates of different Guignardia species. Pathogenicity tests showed that G. citricarpa caused CBS symptoms on citrus fruits, but it did not produce any symptoms in guava fruits. G. mangiferae isolates were able to cause rot symptoms on guava fruits, but they have

Composi??o de exopolissacarídeos produzidos por estirpes de rizóbios cultivados em diferentes fontes de carbono
Castellane, Tereza Cristina Luque;Lemos, Eliana Gertrudes de Macedo;
Pesquisa Agropecuária Brasileira , 2007, DOI: 10.1590/S0100-204X2007001000019
Abstract: the objective of this work was to evaluate the effect of different carbon souces on the exopolysaccharides composition produced by rhizobium tropici semia 4077 and semia 4080, and the effect of these strains inoculation on the nodulation in common bean. the carbon sources used interfered on the concentrations of the galactose and glucose of exopolysaccharides, being higher in semia 4080 strain when cultivated in sucrose medium. even though semia 4080 strain produced a large quantity of exopolysaccharides in culture, there was no difference between strains regarding the number of nodules, independently of the carbon source used for inoculum preparation. however, in the parameter dry weight of nodules there was significant difference between the strains, independently of the carbon sources used for inoculum preparation.
Evaluation of Xylella fastidiosa genetic diversity by fAFPL markers
Kishi, Luciano Takeshi;Wickert, Ester;Lemos, Eliana Gertrudes de Macedo;
Revista Brasileira de Fruticultura , 2008, DOI: 10.1590/S0100-29452008000100037
Abstract: the first phytopathogenic bacterium with its dna entirely sequenced is being detected and isolated from different host plants in several geographic regions. although it causes diseases in cultures of economic importance, such as citrus, coffee, and grapevine little is known about the genetic relationships among different strains. actually, all strains are grouped as a single species, xylella fastidiosa, despite colonizing different hosts, developing symptoms, and different physiological and microbiological observed conditions. the existence of genetic diversity among x. fastidiosa strains was detected by different methodological techniques, since cultural to molecular methods. however, little is know about the phylogenetic relationships developed by brazilian strains obtained from coffee and citrus plants. in order to evaluate it, faflp markers were used to verify genetic diversity and phylogenetic relationships developed by brazilian and strange strains. faflp is an efficient technique, with high reproducibility that is currently used for bacterial typing and classification. the obtained results showed that brazilian strains present genetic diversity and that the strains from this study were grouped distinctly according host and geographical origin like citrus-coffee, temecula-grapevine-mulberry and plum-elm.
Microenxertia em cultivares de manga
Zaccaro, Ronaldo Posella;Donadio, Luiz Carlos;Lemos, Eliana Gertrudes Macedo;
Revista Brasileira de Fruticultura , 2006, DOI: 10.1590/S0100-29452006000300044
Abstract: this research was carried out with the purpose to produce mangoes trees free of fungus fusarium subglutinans, causal agent of mango malformation by using the apex meristem to substitute it for the meristem of the commercial cultivar tommy atkins. this micrografting methodology was denominated "meristem substitution" through which the cultivars coquinho, espada, ouro and ubá were used as rootstocks. the micrografts were collected from 'tommy atkins' mother plant without malformation symptoms. firstly, branch apexes were cut off having length of 3 cm. each apex meristem was placed in an antioxidant solution composed of ascorbic acid, citric acid and cistein, to avoid the oxidation of the fenolic compounds. the apex meristem was cut with 2 mm length. the apex meristem and leaves of the rootstock were also cut off then the apex meristem of tommy atkins was placed on the extremity of the rootstock, being covered with parafilmr. it was demonstrated that micrografting technique may develop matrix plants to implant a cloned garden in the protected greenhouse conditions.
Biosurfactants production by yeasts using soybean oil and glycerol as low cost substrate
Accorsini, Fábio Raphael;Mutton, Márcia Justino Rossini;Lemos, Eliana Gertrudes Macedo;Benincasa, Maria;
Brazilian Journal of Microbiology , 2012, DOI: 10.1590/S1517-83822012000100013
Abstract: biosurfactants are bioactive agents that can be produced by many different microorganisms. among those, special attention is given to yeasts, since they can produce many types of biosurfactants in large scale, using several kinds of substrates, justifying its use for industrial production of those products. for this production to be economically viable, the use of residual carbon sources is recommended. the present study isolated yeasts from soil contaminated with petroleum oil hydrocarbons and assessed their capacity for producing biosurfactants in low cost substrates. from a microbial consortium enriched, seven yeasts were isolated, all showing potential for producing biosurfactants in soybean oil. the isolate lbpf 3, characterized as candida antarctica, obtained the highest levels of production - with a final production of 13.86 g/l. the isolate lbpf 9, using glycerol carbon source, obtained the highest reduction in surface tension in the growth medium: approximately 43% of reduction after 24 hours of incubation. the products obtained by the isolates presented surfactant activity, which reduced water surface tension to values that varied from 34 mn/m, obtained from the product of isolates lbpf 3 and 16 lbpf 7 (respectively characterized as candida antarctica and candida albicans) to 43 mn/m from the isolate lppf 9, using glycerol as substrate. the assessed isolates all showed potential for the production of biosurfactants in conventional sources of carbon as well as in agroindustrial residue, especially in glycerol.
Crescimento in vitro e aclimatiza??o de Cattleya loddigesii Lindley (Orchidaceae) com carv?o ativado sob dois espectros luminosos
Galdiano Júnior, Renato Fernandes;Mantovani, Cibele;Pivetta, Kathia Fernandes Lopes;Lemos, Eliana Gertrudes de Macedo;
Ciência Rural , 2012, DOI: 10.1590/S0103-84782012005000019
Abstract: the aim of this study was to evaluate the effect of different concentrations of activated charcoal in ? ms (half concentration of macronutrients) culture medium under two light spectra on the in vitro growth of cattleya loddigesii seedlings. plantlets with approximately 90 days were subcultured under eight treatments, consisting of different active charcoal concentrations (0; 0.5; 1.0 and 2.0g l-1) in ? ms medium combined with white and red light spectra. after 180 days of germination, biometric data, fresh weight, and the level of photosynthetic pigments were evaluated. plantlets acclimatized in a greenhouse were evaluated for survival after 120 days. total chlorophyll, chlorophyll a, and carotenoid concentrations were higher in treatments under white light, while red light promoted greater chlorophyll b, plantlets with fewer and shorter roots, and high ex vitro mortality. the addition of 2.0g l-1 of active charcoal to the culture medium and the use of white light provided greater development efficiency both on in vitro culture and ex vitro plant survival.
Caracteriza??o de rizóbios indicados para produ??o de inoculantes por meio de sequenciamento parcial do 16S rRNA
Toledo, Bethania Figueiredo Barbosa de;Marcondes, Jackson;Lemos, Eliana Gertrudes de Macedo;
Pesquisa Agropecuária Brasileira , 2009, DOI: 10.1590/S0100-204X2009000400008
Abstract: the aim of this work was to compare the partial sequences of 16s rrna gene of rhizobia strain patterns already classified with strains recommended for the production of inoculants in brazil, in order to verify the reliability of partial sequencing of the gene for the purpose of rapid identification of strains. polymerase chain reaction (pcr) sequencing using primers on the coding region of the 16s rrna gene among the bacteria studied was conducted. the results were analyzed by consulting the nucleotides' similarity based on basic local alignment search tool (blastn) and by interpreting the phylogenetic trees generated by bioinformatic tools. the taxonomic classification of semia strains recommended for legume inoculation based on morphological properties and host specificity was not confirmed in all strains. the similarity of the blastn consultation by partial sequencing of the gene found in strains studied is consistent with the classification proposed by the construction of a phylogenetic tree of sequences of strains in most cases.
Genetic characterization and nitrogen fixation capacity of Rhizobium strains on common bean
González, Tehuni Orlando;Campanharo, Jo?o Carlos;Lemos, Eliana Gertrudes de Macedo;
Pesquisa Agropecuária Brasileira , 2008, DOI: 10.1590/S0100-204X2008000900012
Abstract: this study aimed to genetically characterize four new rhizobium strains, and to evaluate their nodulation and fixation capacity compared to commercial strains and to native rhizobia population of a brazilian rhodic hapludox. two experiments were carried out in randomized blocks design, under greenhouse conditions, in 2007. in the first experiment, the nodulation and nitrogen fixation capacity of new strains were evaluated, in comparison to the commercial strains ciat-899 and prf-81 and to native soil population. it was carried out in plastic tubes filled with vermiculite. dna extractions and pcr sequencing of the intergenic space were made from the isolated pure colonies, in order to genetically characterize the strains and the native rhizobia population. in the second experiment, the nodulation and productivity of common beans perola cultivar were determined, with the use of evaluated strains, alone or in mixture with prf-81 strain. it was carried out in pots filled with soil. the native soil population was identified as rhizobium sp. and was inefficient in nitrogen fixation. three different rhizobium species were found among the four new strains. the lbmp-4br and lbmp-12br new strains are among the ones with greatest nodulation and fixation capacity and exhibit differential responses when mixed to prf-81.
Marcadores fAFLP na caracteriza??o de três genótipos de umezeiro selecionados como porta-enxertos para pessegueiro
Wickert, Ester;Lemos, Eliana Gertrudes de Macedo;Pereira, Fernando Mendes;Mayer, Newton Alex;
Pesquisa Agropecuária Brasileira , 2007, DOI: 10.1590/S0100-204X2007001200011
Abstract: the objective of this work was the identification of faflp markers to be used in molecular characterization of three mume genotypes selected as rootstocks for peach tree. twenty-four different faflp primer combinations were used and allowed the recognition of 648 markers, comprising 272 markers which were able to discriminate the three clones one from the other. these markers were used to calculate the groupment of the clones according to their similarities with the distance method and neighbour joining algorithm. the same markers were also used to calculate the genetic distance among the clones. the faflp markers were efficient to identify the clones, mainly by the combinations of selective primers fam act/cat, joe agg/ctt and ned agc/caa. faflp markers allowed the genetic discrimination of the three mume genotypes. the greatest genetic distance was found between rigitano cultivar and clone 15. the faflp markers also showed greater genetic similarity between clone 05 and rigitano cultivar.
Rea??o enzimática ao estresse salino durante a germina??o de estilosantes
Gonela, Adriana;Lemos, Eliana Gertrudes Macedo;Rodrigues, Teresinha de Jesus Deléo;Paterniani, Maria Lidia Stipp;
Pesquisa Agropecuária Brasileira , 2004, DOI: 10.1590/S0100-204X2004000100014
Abstract: the objective of this work was to evaluate the influence of the nac1 on isoenzyme systems during the initial stage of germination of stylosanthes guianensis (aubl.) sw. seeds of the botanical varieties canenscens, microcephala, pauciflora and vulgaris were placed to germinate in plastic boxes, with filter paper moistened with water (control) and nac1 solution(134 mmol), in bod greenhouse, for 14 hours. after this period, the extraction of glutamate dehydrogenase ensymes and peroxidase was carried out. the enzymes presented differentiated behaviors in the four varieties when subjected to the saline stress.
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