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Search Results: 1 - 10 of 163665 matches for " Fábio Lopes;Bressan-Smith "
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Structural interaction between GFP-labeled diazotrophic endophytic bacterium Herbaspirillum seropedicae RAM10 and pineapple plantlets 'Vitória'
Baldotto, Lílian Estrela Borges;Olivares, Fábio Lopes;Bressan-Smith, Ricardo;
Brazilian Journal of Microbiology , 2011, DOI: 10.1590/S1517-83822011000100015
Abstract: the events involved in the structural interaction between the diazotrophic endophytic bacterium herbaspirillum seropedicae, strain ram10, labeled with green fluorescent protein, and pineapple plantlets 'vitória' were evaluated by means of bright-field and fluorescence microscopy, combined with scanning electron microscopy for 28 days after inoculation. after 6 hours of inoculation, h. seropedicae was already adhered to the roots, colonizing mainly root hair surface and bases, followed by epidermal cell wall junctions. bacteria adherence in the initial periods occurred mainly in the form of solitary cells and small aggregates with pleomorphic cells. bacteria infection of root tissue occurred through the cavities caused by the disruption of epidermal cells during the emergence of lateral roots and the endophytic establishment by the colonization of intercellular spaces of the cortical parenchyma. moreover, within 1 day after inoculation the bacteria were colonizing the shoots. in this region, the preferred sites of epiphytic colonization were epidermal cell wall junctions, peltate scutiform trichomes and non-glandular trichomes. subsequently, the bacteria occupied the outer periclinal walls of epidermal cells and stomata. the penetration into the shoot occurred passively through stoma aperture followed by the endophytic establishment on the substomatal chambers and spread to the intercellular spaces of spongy chlorenchyma. after 21 days of inoculation, bacterial biofilm were seen at the root hair base and on epidermal cell wall surface of root and leaf, also confirming the epiphytic nature of h. seropedicae.
Sele??o de bactérias promotoras de crescimento no abacaxizeiro cultivar Vitória durante a aclimatiza??o
Baldotto, Lílian Estrela Borges;Baldotto, Marihus Altoé;Olivares, Fábio Lopes;Viana, Alexandre Pio;Bressan-Smith, Ricardo;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000200008
Abstract: pineapple (ananas comosus l. merrill) in vitro propagation results in the production of a large quantity of healthy and homogeneous plantlets. despite these advantages, the long time required for acclimatization makes this agricultural practice too costly. growth acceleration of plantlets by inoculation with endophytic and epiphytic diazotrophic bacteria may be useful to reduce this period. the objectives of this study were to evaluate the potential of 20 diazotrophic bacteria strains in synthesizing indole, solubilizing ca phosphate and zn oxide and acting against the fungus fusarium subglutinans f. sp. ananas, and subsequently, evaluate the performance of pineapple 'vitória' propagated by tissue culture in response to the application of these isolates during the acclimatization period in a greenhouse. shoot and root growth characteristics and leaf nutrient content of pineapple were evaluated. results showed differences in the ability of the bacteria strains to synthesize indole, solubilize ca phosphate and zn oxide and act against fusarium. differences in the growth-promoting capacity of the shoot and root system of bacteria and leaf accumulation of n, p, k, ca and mg in pineapple were also shown. inoculation with diazotrophic bacteria can promote the growth of plantlets during the acclimatization period, improving the adaptation of pineapple to the ex-vitro environment
Growth promotion of pineapple 'vitória' by humic acids and burkholderia spp. during acclimatization
Baldotto, Lílian Estrela Borges;Baldotto, Marihus Altoé;Canellas, Luciano Pasqualoto;Bressan-Smith, Ricardo;Olivares, Fábio Lopes;
Revista Brasileira de Ciência do Solo , 2010, DOI: 10.1590/S0100-06832010000500012
Abstract: in vitro propagation of pineapple produces uniform and disease-free plantlets, but requires a long period of acclimatization before transplanting to the field. quicker adaptation to the ex vitro environment and growth acceleration of pineapple plantlets are prerequisites for the production of a greater amount of vigorous, well-rooted planting material. the combination of humic acids and endophytic bacteria could be a useful technological approach to reduce the critical period of acclimatization. the aim of this study was to evaluate the initial performance of tissue-cultured pineapple variety vitória in response to application of humic acids isolated from vermicompost and plant growth-promoting bacteria (burkholderia spp.) during greenhouse acclimatization. the basal leaf axils were treated with humic acids while roots were immersed in bacterial medium. humic acids and bacteria application improved shoot growth (14 and 102 %, respectively), compared with the control; the effect of the combined treatment was most pronounced (147 %). likewise, humic acids increased root growth by 50 %, bacteria by 81 % and the combined treatment by 105 %. inoculation was found to significantly increase the accumulation of n (115 %), p (112 %) and k (69 %) in pineapple leaves. pineapple growth was influenced by inoculation with burkholderia spp., and further improved in combination with humic acids, resulting in higher shoot and root biomass as well as nutrient contents (n 132 %, p 131 %, k 80 %) than in uninoculated plantlets. the stability and increased consistency of the host plant response to bacterization in the presence of humic substances indicate a promising biotechnological tool to improve growth and adaptation of pineapple plantlets to the ex vitro environment.
Desempenho do abacaxizeiro 'Vitória' em resposta à aplica??o de ácidos húmicos durante a aclimata??o
Baldotto, Lílian Estrela Borges;Baldotto, Marihus Altoé;Giro, Validoro Bazoni;Canellas, Luciano Pasqualoto;Olivares, Fábio Lopes;Bressan-Smith, Ricardo;
Revista Brasileira de Ciência do Solo , 2009, DOI: 10.1590/S0100-06832009000400022
Abstract: the acclimatization of pineapple plantlets propagated by plant tissue culture is slow. the intensification of root growth by the use of humic acids may be useful during this process. the aim of this study was to evaluate the greenhouse acclimatization of 'vitória' pineapple propagated by plant tissue culture in response to different doses of humic acids isolated from vermicompost and filter cake. leaf anatomy, photosynthetic pigment content, shoot and root growth, and leaf nutrients were evaluated. an increase in growth and development of shoots and root system with the application of humic acids as well as a significant accumulation of n, p, k, ca, and mg and increase in the chlorophyll a / chlorophyll b ratio were found. growth promotion by the application of humic acids to plantlets during the period of acclimatization can improve their adaptation to the ex vitro environmental conditions.
Genetic linkage map of Phaseolus vulgaris and identification of QTLs responsible for resistance to Xanthomonas axonopodis pv. phaseoli
Santos, Amaury S.;Bressan-Smith, Ricardo E.;Pereira, Messias G.;Rodrigues, Rosana;Ferreira, Claudia F.;
Fitopatologia Brasileira , 2003, DOI: 10.1590/S0100-41582003000100001
Abstract: common bean (phaseolus vulgaris) cultivars with a high degree of resistance to xanthomonas axonopodis pv. phaseoli (xap) are not available in brazil. despite many studies, a low degree of resistance to xap continues to exist due to its complex genetic inheritance, which is not well known. the objectives of this research were to complement a common bean genetic map based on the cross between a susceptible genotype 'hab-52' and a resistant genotype 'bac-6', and to map and analyze genomic regions (quantitative trait loci – qtls) related to xap resistance. eleven linkage groups were determined using 143 rapd markers, covering 1,234.5 cm of the genome. this map was used to detect qtls associated with xap resistance on leaves and pods. the averages of disease severity on leaves (represented by the transformed disease index – tdi) and pods (represented by the diameter of lesion on pods – dlp) were added to the data of the linkage map. five tdi qtls and only one ldp qtl were detected. the tdi qtls were placed in the a, b, g and j linkage groups, with phenotypic variations ranging from 12.7 to 71.6%. the dlp qtl explained 12.9% of the phenotypic variation and was mapped in a distinct linkage group. these results indicate that there are different genes involved in the control of resistance on leaves and pods.
Caracteriza??o e avalia??o agron?mica de híbridos e linhagens de milho doce (su1)
Oliveira Jr, Luiz Fernando G;Pereira, Messias G;Bressan-Smith, Ricardo;
Horticultura Brasileira , 2006, DOI: 10.1590/S0102-05362006000300003
Abstract: two sweet-corn (su-1 mutant and common-corn) hybrids, as well as the respective parentals and donators, summing up 11 genetic materials, were evaluated in two environments, in itaocara and campos dos goytacazes, rio de janeiro state, brazil. the sweet-corn hybrids were obtained by simple crosses between sweet-corn parentals carrying the gene su-1, transferred by backcross. heterosis, the genotypic determination coefficient and morphoagronomic traits were evaluated. the experimental design consisted of randomized blocks, with two replications in each environment. four-row plots, 5-m long, were used. the two sweet-corn hybrids overcame their parentals and donators. comparison between sweet- and common-corn hybrids showed no significant differences. heterosis was detected in almost all traits, as for example, yield of ears without straw and percent of ears damaged by pests, as well as significant genotypic influence, revealed by the genotypic determination coefficient.
Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress
Costa, Ernany Santos;Bressan-Smith, Ricardo;Oliveira, Jurandi Gon?alves de;Campostrini, Eliemar;Pimentel, Carlos;
Brazilian Journal of Plant Physiology , 2002, DOI: 10.1590/S1677-04202002000200004
Abstract: bean (phaseolus vulgaris l., cv. carioca and cv. negro huasteco) and cowpea plants (vigna unguiculata l. walp cv. epace 10) were grown in a growth chamber with ppf at leaf level of 200 mmol.m-2.s-1 and air temperature 25 + 1 oc. the first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 oc) for 1.5 h. the photochemical efficiency of psii during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 oc, using a modulated fluorimeter. increasing temperature promoted an increase in ff at 45 oc, possibly associated with dissociation of the light harvesting complex from the reaction centre of psii, but a decrease was observed at 48 oc in all cultivars. fmax decreased at 48 oc in carioca and negro huasteco, but not in epace 10, showing a possible correlation between heat tolerance and fmax for this cultivar. the low values of fmax in carioca and negro huasteco indicated a loss of psii activity followed by death of these plants. fv/fmax did not vary in epace 10 but varied in carioca and negro huasteco with increasing temperatures.
Potencial climático para a produ??o de uvas em Campos dos Goytacazes, regi?o norte Fluminense
Pommer, Celso Valdevino;Mendes, Luciane Siqueira;Hespanhol-Viana, Landro;Bressan-Smith, Ricardo;
Revista Brasileira de Fruticultura , 2009, DOI: 10.1590/S0100-29452009000400022
Abstract: multicriteria climatic classification system (geoviticulture mcc system) based on three climate indexes, the dryness index (di), which corresponds to an indicator of the dryness level, the heliothermal index (hi), which corresponds to huglin's heliothermal index, and the cool night index (ci), that acts as an indicator of night temperature conditions during berry maturation, was able to describe the climatic potential for vineyards around the world. in this study we characterized the viticulture climate on twelve growth-production periods during a year with four months duration each, in the north region of the state of rio de janeiro, represented by campos dos goytacazes municipality (21o 45's, 41o 19'w, 13 m). the system indicated that the region has potential for grape production during the year through markedly differences in di, hi and ci indexes. the 4-months periods of january/april, february/may, march/june, april/july, may/august, june/september, july/october and august/november were considered the most suitable for grape production, as the indexes show: is+1 indicating moderate drought class, ih-2 to ih-1, for cold to temperate classes, except for january/april, with ih+1, for temperate warm class, and if-2 to if-1 from warm to temperate nights classes. it can be seen that these periods shows climatic potential, and as allowing adequate plant growth, are satisfactory also for diminishing needs of sprayings and coinciding with low product offer and higher prices, what turns the region with suitability for more than one cycle per year. in this study, the system allowed the distinction of periods of grape-growing throughout a year, acting as appropriate tool for viticulture zoning.
Genetic linkage map of Phaseolus vulgaris and identification of QTLs responsible for resistance to Xanthomonas axonopodis pv. phaseoli
Santos Amaury S.,Bressan-Smith Ricardo E.,Pereira Messias G.,Rodrigues Rosana
Fitopatologia Brasileira , 2003,
Abstract: Common bean (Phaseolus vulgaris) cultivars with a high degree of resistance to Xanthomonas axonopodis pv. phaseoli (Xap) are not available in Brazil. Despite many studies, a low degree of resistance to Xap continues to exist due to its complex genetic inheritance, which is not well known. The objectives of this research were to complement a common bean genetic map based on the cross between a susceptible genotype 'HAB-52' and a resistant genotype 'BAC-6', and to map and analyze genomic regions (quantitative trait loci - QTLs) related to Xap resistance. Eleven linkage groups were determined using 143 RAPD markers, covering 1,234.5 cM of the genome. This map was used to detect QTLs associated with Xap resistance on leaves and pods. The averages of disease severity on leaves (represented by the transformed disease index - TDI) and pods (represented by the diameter of lesion on pods - DLP) were added to the data of the linkage map. Five TDI QTLs and only one LDP QTL were detected. The TDI QTLs were placed in the A, B, G and J linkage groups, with phenotypic variations ranging from 12.7 to 71.6%. The DLP QTL explained 12.9% of the phenotypic variation and was mapped in a distinct linkage group. These results indicate that there are different genes involved in the control of resistance on leaves and pods.
Photochemical efficiency in bean plants (Phaseolus vulgaris L. and Vigna unguiculata L. Walp) during recovery from high temperature stress
Costa Ernany Santos,Bressan-Smith Ricardo,Oliveira Jurandi Gon?alves de,Campostrini Eliemar
Brazilian Journal of Plant Physiology , 2002,
Abstract: Bean (Phaseolus vulgaris L., cv. Carioca and cv. Negro Huasteco) and cowpea plants (Vigna unguiculata L. Walp cv. Epace 10) were grown in a growth chamber with PPF at leaf level of 200 mumol.m-2.s-1 and air temperature 25 + 1 oC. The first fully expanded pair of leaves of 12-day-old plants was submitted to high temperature stress (25, 30, 35, 40, 45 and 48 oC) for 1.5 h. The photochemical efficiency of PSII during recovery was monitored by means of chlorophyll a fluorescence at six different times (0.5, 1, 2, 4, 24, and 48 h) after stress, at 25 oC, using a modulated fluorimeter. Increasing temperature promoted an increase in Fphi at 45 oC, possibly associated with dissociation of the light harvesting complex from the reaction centre of PSII, but a decrease was observed at 48 oC in all cultivars. Fmax decreased at 48 oC in Carioca and Negro Huasteco, but not in Epace 10, showing a possible correlation between heat tolerance and Fmax for this cultivar. The low values of Fmax in Carioca and Negro Huasteco indicated a loss of PSII activity followed by death of these plants. Fv/Fmax did not vary in Epace 10 but varied in Carioca and Negro Huasteco with increasing temperatures.
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