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Search Results: 1 - 10 of 50199 matches for " Antonio Teixeira do; "
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Efeitos do alumínio, nitrato e am?nio sobre a composi??o de metabólitos nitrogenados e de carboidratos em Stylosanthes guianensis e S. macrocephala
AMARAL, JOSé AUGUSTO TEIXEIRA DO;CORDEIRO, ANTONIO TEIXEIRA;RENA, ALEMAR BRAGA;
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000000200010
Abstract: the effects of aluminum, nitrate and ammonium interaction, in nutritive solution, on the concentration of nitrogened compound, and of sugar in stylosanthes guianensis and s. macrocephala, sensitive and tolerant, respectively, both to aluminum and to ammonium were studied under controlled conditions. the ammonium nutrition caused the appearance of toxicity symptoms of ammonium only in the s. guianensis. the ammonium source increased the concentrations of n-soluble, n-ammonium and n-amino acid mainly in the aerial part of the s. guianensis and in the root system of the s. macrocephala, while the total soluble sugar concentration increased in the aerial part of the s. guianensis and decreased in the root system of both species. the aluminum relieved partially the ammonium toxicity in the s. guianensis. when the nitrogen was supplied by the nitric source, the addition of the aluminum to the nutritive solution caused the appearance of symptoms of toxicity only in the s. guianensis. in the s. macrocephala, under the same conditions, an increase of total n, insoluble n, soluble n, nitric n and amino acid n in the aerial part and in the roots ocurred, followed by a decrease in the total soluble sugar concentration and sugar reductor in the roots.
Efeitos do alumínio, nitrato e am nio sobre a composi o de metabólitos nitrogenados e de carboidratos em Stylosanthes guianensis e S. macrocephala
AMARAL JOSé AUGUSTO TEIXEIRA DO,CORDEIRO ANTONIO TEIXEIRA,RENA ALEMAR BRAGA
Pesquisa Agropecuária Brasileira , 2000,
Abstract: Estudaram-se, em condi es controladas, os efeitos da intera o de alumínio, nitrato e am nio, em solu o nutritiva, sobre os teores de compostos nitrogenados e de a úcares em Stylosanthes guianensis e S. macrocephala, sensível e tolerante, respectivamente, tanto ao Al quanto ao am nio. A nutri o amoniacal causou o aparecimento de sintomas de toxidez de am nio apenas em S. guianensis. A fonte amoniacal aumentou as concentra es de N-solúvel, N-amoniacal e N-aminoácidos principalmente na parte aérea de S. guianensis e no sistema radicular de S. macrocephala, ao passo que os teores de a úcares solúveis totais aumentaram na parte aérea de S. guianensis e decresceram no sistema radicular das duas espécies. O Al atenuou parcialmente a toxidez de am nio em S. guianensis. Quando o N foi suprido pela fonte nítrica, a adi o do Al à solu o nutritiva causou o aparecimento de sintomas de toxidez apenas em S. guianensis. Já em S. macrocephala, nessas condi es, ocorreram aumentos nos teores de N-total, N-insolúvel, N-solúvel, N-nítrico e N-aminoácidos na parte aérea e nas raízes, seguidos de decréscimos nos teores de a úcares solúveis totais e redutores nas raízes.
Genetic Variability among Genotypes of Physic Nut Regarding Seed Biometry  [PDF]
Leonardo Fardim Christo, Tafarel Victor Colodetti, Wagner Nunes Rodrigues, Lima Deleon Martins, Sebasti?o Batista Brinate, José Francisco Teixeira do Amaral, Bruno Galvêas Laviola, Marcelo Antonio Tomaz
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.510156
Abstract:

With probable center of origin in Brazil, the species Jatropha curcas L., known as physic nut, is a tropical oilseed with potential for cultivation aiming at the production of biodiesel. This study was conducted with the objective of investigating the genetic variability regarding the morphology of seeds of physic nut, using biometric analyses to identify variables that have potential for the study of the diversity of the species and the classification of genotypes. Seeds of 22 genotypes of physic nut, from the germplasm bank of Embrapa Agroenergia (Brazil) were evaluated regarding characteristics of size and mass. The genotypes of Jatropha curcas L. selected by the Brazilian breeding program presented high diversity for characteristics of the seeds, allowing the exploration of this genetic variability to classify genotypes in different groups. In addition, variables related to the biomass of the seeds present high relative contributions to the diversity observed in the genotypes.

Differential Growth of Genotypes of Physic Nut Conditioned by Nitrogen Fertilization  [PDF]
Tafarel Victor Colodetti, Leonardo Fardim Christo, Lima Deleon Martins, Wagner Nunes Rodrigues, José Francisco Teixeira do Amaral, Bruno Galvêas Laviola, Marcelo Antonio Tomaz
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.514228
Abstract:

The adequate supply of nitrogen is essential for the plant metabolism. This nutrient has an irreplaceable role on the vegetative and reproductive growth of physic nut; therefore the correct management of the fertilization is very important, particularly in tropical regions, which present considerable losses of nitrogen by leaching and volatilization processes. This study was made with the objective of evaluating the growth of genotypes of physic nut conditioned by nitrogen fertilization. The experiment was conducted in controlled environment, following a factorial scheme 12 × 4, with 12 Brazilian genotypes of Jatropha curcas L. and 4 levels of nitrogen fertilization (0%, 50%, 100% and 150% of the recommendation), in completely randomized design, with four replications. The growth of the genotypes was evaluated at 100 days of cultivation. Positive response to the increase in the nitrogen supply was observed in most genotypes, with gain in plant height, stem diameter, number of leaves, leaf area and root volume. The levels of nitrogen fertilization promoted differential growth between genotypes, being possible to identify genotypes with superior growth for each level.

Applicability of the Method of Linear Dimensions to Estimate Leaf Area in Improved Genotypes of Coffea arabica and Coffea canephora  [PDF]
Sebasti?o Vinícius Batista Brinate, Wagner Nunes Rodrigues, Lima Deleon Martins, Tafarel Victor Colodetti, Marcelo Antonio Tomaz, José Francisco Teixeira do Amaral
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.65070
Abstract: There are different methods to determinate leaf area in coffee plants; however, methodologies that allow measurement of leaf area accurately and in nondestructive ways are very important, as they are less economically costly and enable measurements on the same leaf over time, making it possible to describe accurate patterns of growth. The objective of this study was to investigate the applicability of the method to estimate leaf area using linear dimensions of leaves for improved genotypes of Coffea arabica L. and Coffea canephora Pierre ex A. Froehner. The experiment was conducted in two separated competition fields, each one following factorial schemes 10 × 2, with 10 genotypes and 2 methods to obtain the leaf area: measuring linear dimensions, and using equation model (estimated leaf area) and leaf area integrator (real leaf area). The genotypes for both Coffea arabica L. and Coffea canephora Pierre ex A. Froehner have different leaf areas, making it possible to discriminate groups of genotypes for both species using the size of their leaves as classification criteria. Even with the differences between genotypes, the pattern of leaf shape remains similar, confirming the applicability of the method to estimate leaf area using linear dimensions of leaves for improved genotypes, such as the model proposed by Barros, without the occurrence of loss of accuracy for the improved genotypes, for both Arabica and Conilon coffee, studied in this experiment.
Severity of Leaf Rust and Brown Eyespot in Genotypes of Coffea arabica L. Cultivated with High Plant Density  [PDF]
Wagner Nunes Rodrigues, Marcelo Antonio Tomaz, Márcio Antonio Apostólico, Tafarel Victor Colodetti, Lima Deleon Martins, Leonardo Fardim Christo, Sebasti?o Vinícius Batista Brinate, Waldir Cintra de Jesus Jr., José Francisco Teixeira do Amaral
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.525386
Abstract:
This study investigated the severity of leaf rust and brown eyespot in genotypes of Coffea arabica L. cultivated with high plant density in the region of Caparaó-ES. The experiment was conducted in a competition field, cultivated with high plant density (8333 plants per hectare), following a randomized block design, with 16 genotypes and four replications. The plants were evaluated during consecutive harvests to study two complete reproductive cycles (from 2010 to 2012). Data were obtained for the phenologicalstages of flowering, graining, maturation and vegetative rest of each cycle. The severity of leaf rust (Hemileia vastratrix) and brown eyespot (Cercospora coffeicola) was evaluated using descriptive scales. It was observed that the genotypes are able to keep a considerable level of resistance to the leaf rust and brown eyespot when cultivated with increased density. The genotypes presented variability regarding the severity of the leaf rust and brown eyespot, indicating the existence of differential levels of resistance between them. For cultivation with high plant density, the genotypes Katipó, Paraíso MG H419-1, H419-3-3-7-16-4-1-1, Araponga MG1, Catucaí Amarelo 24/137, Catiguá MG2, Sacramento MG1, Pau-Brasil MG1, Catiguá MG3, Oeiras MG 6851 and Tupi present higher level of resistance for leaf rust. In addition, the genotypes Paraíso MG H419-1, Catiguá MG2, Pau-Brasil MG1, Catiguá MG3, Oeiras MG 6851, Tupi, Catuaí IAC 44, Catuaí IAC 81 and Catuaí IAC 144 present higher level of resistance for brown eyespot.
Generalized composite interval mapping offers improved efficiency in the analysis of loci influencing non-normal continuous traits
Mora,Freddy; Scapim,Carlos Alberto; Baharum,Adam; Teixeira do Amaral Júnior,Antonio;
Ciencia e investigación agraria , 2010, DOI: 10.4067/S0718-16202010000300007
Abstract: in genetic studies, most quantitative trait loci (qtl) mapping methods presuppose that the continuous trait of interest follows a normal (gaussian) distribution. however, many economically important traits of agricultural crops have a non-normal distribution. composite interval mapping (cim) has been successfully applied to the detection of qtl in animal and plant breeding. in this study we report a generalized cim (gcim) method that permits qtl analysis of non-normally distributed variables. gcim was based on the classic generalized linear model method. we applied the gcim method to a f2 population with co-dominant molecular markers and the existence of a qtl controlling a trait with gamma distribution. computer simulations indicated that the gcim method has superior performance in its ability to map qtl, compared with cim. qtl position differed by 5 cm and was located at different marker intervals. the likelihood ratio test values ranged from 52 (gcim) to 76 (cim). thus, wrongly assuming cim may overestimate the effect of the qtl by about 47%. the usage of gcim methodology can offer improved efficiency in the analysis of qtls controlling continuous traits of non-gaussian distribution.
Associa??o entre características agron?micas e capacidade de expans?o em popula??o de milho pipoca sob sele??o recorrente
Rangel, Ramon Macedo;Amaral Júnior, Antonio Teixeira do;Freitas Júnior, Silvério de Paiva;
Ciência e Agrotecnologia , 2011, DOI: 10.1590/S1413-70542011000200001
Abstract: the objective of this work was to investigate the possibility of a more efficient selection through path analysis and partial correlation in the breeding program of the uenf popcorn population by recurrent selection. two hundred full-sib progenies were obtained and evaluated by eight traits in two environments in rio de janeiro state: campos dos goytacazes and itaocara. the genotypic correlation between popping expansion and grain yield was negative and non significant at the 5% probability level by t test. path analysis showed that mass weight of 100 grains is the most associated trait at popping expansion in this study. it is possible to obtain correlated response for popping expansion by grain yield, as long as genotypes with smaller grain size are selected from the genotypes with higher grain yield.
Genetic diversity in Australian Cedar genotypes selected by mixed models
Tavares, Rulfe;Viana, Alexandre Pio;Barroso, Deborah Guerra;Amaral Júnior, Antonio Teixeira do;
Ciência e Agrotecnologia , 2012, DOI: 10.1590/S1413-70542012000200005
Abstract: the increasing demand for raw material for multiple uses of forest products and by-products has attracted the interest for fast growing species, such as the australian cedar (toona ciliata), which presents high productive and economic potential. the present work aimed at estimating genetic diversity by dna markers and morphological traits supported for the mixed models. the following traits were measured and genotypes were sampled randomly in different areas: diameter at breast height, height, cylindrical volume, diameter, distance between nodes and crown diameter. twelve rapd primers were used and generated a total of 91 marks, 82 of which were polymorphic. the high percentage of polymorphic markers, 90.10%, demonstrated that discrimination in this species is efficient, but it yet little studied, for this case we can find the extent of the genetic basis for the application of technical improvement. the assessment of genetic diversity by the upgma method using the binary and morphological data provided the expression of genetic dissimilarities among the accessions evaluated, optimizing the perception of this divergence. the use of mixed models was efficient to assess combined genetic diversity to optimize the selection of genotypes with divergent genetic values for diameter at breast height.
Efeito da fitase na biodisponibilidade do fósforo do farelo de arroz em frangos de corte
Conte Ademir José,Teixeira Antonio Soares,Figueirêdo Agostinho Valente de,Vitti Dorinha Miriam Silber Schimidt
Pesquisa Agropecuária Brasileira , 2002,
Abstract: O trabalho objetivou determinar a a o da enzima fitase sobre a biodisponibilidade do fósforo do farelo de arroz em dietas de frangos de corte, pela técnica de dilui o isotópica. Os tratamentos consistiram de uma dieta sem farelo de arroz integral e sem suplementa o de fósforo inorganico (0,388% de P total), e quatro dietas com 15% de farelo de arroz integral, sem suplementa o de fósforo inorganico (0,56% de P total) e com quatro níveis de fitase (0, 400, 800 e 1,200 FTU/kg). No quinto dia do experimento, cada ave recebeu, via peritonial, 3,5 MBq de 32P. Nos quatro dias subseqüentes, coletaram-se amostras de sangue e excretas para as análises. As perdas endógenas fecais, a absor o aparente e verdadeira de fósforo e o fósforo no plasma aumentaram de maneira significativa (P<0,01) com a utiliza o de níveis crescentes de fitase. A biodisponibilidade do fósforo foi de 38,06% na dieta com farelo de arroz e sem enzima, e aumentou para 51,54%, 61,31% e 59,54% com a utiliza o de 400, 800 e 1.200 FTU/kg, respectivamente. Por meio de regress o quadrática, determinou-se a máxima biodisponibilidade de P, que foi de 60,8% com a utiliza o de 982 FTU/kg. A biodisponibilidade do fósforo do farelo de arroz, determinada por fracionamento, foi de 28,1% e aumentou de forma linear (P<0,05) para 38,3%, 50,2% e 54,0%, com a utiliza o de 400, 800 e 1.200 FTU/kg.
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