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Search Results: 1 - 10 of 65166 matches for " Pereira Pedro Antonio Arraes "
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COMPARISON BETWEEN BREEDING METHODS TO ENHANCE NITROGEN FIXATION IN THE COMMON BEAN (Phaseolus vulgaris L.) COMPARA O DE MéTODOS DE MELHORAMENTO DE FEIJ O (Phaseolus vulgaris L.) PARA O INCREMENTO DA FIXA O SIMBIóTICA DE NITROGêNIO
Pedro Antonio Arraes Pereira,Wladimir Braidotti
Pesquisa Agropecuária Tropical , 2007, DOI: 10.5216/pat.v31i1.2510
Abstract: The common bean productivity can be improved by the increment of its capacity of nitrogen fixation in the symbiosis with bacteria of genus Rhizobium. This study had the objective to compare two breeding methodologies - F2 derived lines (LDF2) and single seed descent (SSD) in a cross among the cultivars Negro Argel (good Symbiotic N2 fixer) and Rio Tibagi (poor symbiotic N2 fixar) conducted with Rhizobium inoculation or mineral nitrogen. Eighteen families were selected on F4 in the LDF2 method based on nitrogen content in the grains and at the SSD method sixty seeds were carried out to F5 without selection. Families selected on F4 generation (LDF2) were superior for N2 fixation potential and grain yield in comparison with families that were conducted without selection (SSD) bean families selected in the F4 generation under mineral nitrogen treatment showed a tendency to respond less to inoculation then families selected under Rhizobium treatment. Furthermore, families selected under Rhizobium treatment showed better response when grown under the mineral nitrogen treatment. The same tendency was observed for families which respond to both sources of nitrogen. In this study was observed that selection under Rhizobium pressure provide a opportunity to plant breeders to select bean genotypeswith enhance nitrogen fixation potential and high grain yield. KEY-WORDS: Nodulation; total N; grain yield. A produtividade do feij o pode ser melhorada pelo incremento da sua capacidade de fixar nitrogênio através de bactérias do gênero Rhizobium. Este estudo comparou duas metodologias de melhoramento – linhas derivadas de F2 (LDF2) e descendência de uma única semente (SSD), – em um cruzamento entre as cultivares Negro Argel (bom fixador simbiótico de nitrogênio) e Rio Tibagi (baixo potencial simbiótico de nitrogênio), com nitrogênio mineral ou inocula o com Rhizobium. Dezoito famílias foram selecionadas em F4 pelo método LDF2, com base no N total nos gr os, e sessenta sementes foram avan adas até F5 sem sele o, pelo método SSD. As famílias selecionadas em F4 (LDF2) foram superiores para o potencial de fixa o de nitrogênio e produ o de gr os, em compara o com famílias conduzidas sem sele o (SSD). As famílias F4 selecionadas no tratamento com nitrogênio mineral mostraram uma tendência a responder menos à inocula o, do que as famílias selecionadas no tratamento com Rhizobium. Além disso, as famílias selecionadas no tratamento com Rhizobium mostraram melhores respostas no tratamento com nitrogênio mineral. A mesma tendência foi observada para as famílias que responde
Preservation of rhizobia by lyophilization with trehalose
Pereira, Pedro Antonio Arraes;Oliver, Ann;Bliss, Fredrick Allen;Crowe, Lois;Crowe, John;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000600012
Abstract: the objective of this study was to determine if trehalose can effectively enhance the viability and storage lifetime of rhizobium tropici and rhizobium etli after lyophilization as compared to the traditional protective combination of sucrose and peptone. two strains of bean-nodulating rhizobia were effectively preserved in the lyophilized state by 100 mm trehalose, and survived for at least 12 days, even when stored under non-ideal conditions. trehalose provided better protection than the sucrose/peptone combination. when protective excipients were introduced inside the cells, strain cfn 42 was more sensitive to the type of additive used than strain ciat 899, probably because ciat 899 produces b (1-2) glucan, which may have a protective effect. b (1-2) glucan combined with sucrose protected better than trehalose against leakage from freeze-dried liposomes, but by itself it had no protective capability. there was a high level of unfrozen water associated with the hydrated glucan, in addition to a thermal event at approximately 70oc, corresponding to an observed gel-sol transition in the glucan. these findings may shed light on the mechanism by which the glucan contributes to the protection of dried cells and liposomes, and may lead to further improvements in rhizobial inoculants.
Preservation of rhizobia by lyophilization with trehalose
Pereira Pedro Antonio Arraes,Oliver Ann,Bliss Fredrick Allen,Crowe Lois
Pesquisa Agropecuária Brasileira , 2002,
Abstract: The objective of this study was to determine if trehalose can effectively enhance the viability and storage lifetime of Rhizobium tropici and Rhizobium etli after lyophilization as compared to the traditional protective combination of sucrose and peptone. Two strains of bean-nodulating rhizobia were effectively preserved in the lyophilized state by 100 mM trehalose, and survived for at least 12 days, even when stored under non-ideal conditions. Trehalose provided better protection than the sucrose/peptone combination. When protective excipients were introduced inside the cells, strain CFN 42 was more sensitive to the type of additive used than strain CIAT 899, probably because CIAT 899 produces beta (1-2) glucan, which may have a protective effect. beta (1-2) glucan combined with sucrose protected better than trehalose against leakage from freeze-dried liposomes, but by itself it had no protective capability. There was a high level of unfrozen water associated with the hydrated glucan, in addition to a thermal event at approximately 70oC, corresponding to an observed gel-sol transition in the glucan. These findings may shed light on the mechanism by which the glucan contributes to the protection of dried cells and liposomes, and may lead to further improvements in rhizobial inoculants.
Marker-assisted selection for the rice blast resistance gene Pi-ar in a backcross population
Leila Garcês de Araújo,Anne Sitarama Prabhu,Pedro Antonio Arraes Pereira,Gisele Barata da Silva
Crop Breeding and Applied Biotechnology , 2010,
Abstract: A doubled-haploid (DH) population, obtained by anther culture of F1 plants from a cross between a highlysusceptible rice cultivar Lijiangxintuanheigu and the resistant somaclone (SC09), of the cultivar Araguaia, was used to identifyRAPD markers linked to the blast resistance gene Pi-ar. The 86 DH plants, inoculated with the race IB-9 of Magnaportheoryzae, segregated in 1:1 ratio of resistant and susceptible plants. Of the 67 primers used 31 produced DNA profiles thatdifferentiated resistant and susceptible bulks as well as the parental cultivars. The resistance gene was found linked to theprimer OPS162072 (‘AGGGGGTTCC’) at a distance of 3.6 cM. The selection efficiency of this primer was assessed in a BC3 F1population derived from another cross between a susceptible cultivar IAC 201 and SC09. The marker OPS16 showedefficiency of 86.9%, when six resistant and two susceptible plants were considered as negatives in RAPD analysis.
Controle do caruncho-do-feijoeiro Zabrotes subfasciatus com óleos vegetais, munha, materiais inertes e malathion
Barbosa, Flávia Rabelo;Yokoyama, Massaru;Pereira, Pedro Ant?nio Arraes;Zimmermann, Francisco José Pfeilsticker;
Pesquisa Agropecuária Brasileira , 2002, DOI: 10.1590/S0100-204X2002000900002
Abstract: the effects of malathion 500 ce, neem (azadirachta indica a. juss.) and soybean (glycine max merrill) oils, inert materials and trashing residues on the control of zabrotes subfasciatus (coleoptera:bruchidae) were evaluated on bean seeds (phaseolus vulgaris l.), using the cultivar carioca and two lines containing the protein arcelin (arc1 and arc3). the experiment was carried in a laboratory at embrapa-centro nacional de pesquisa de arroz e feij?o, santo ant?nio de goiás, go, brazil, under noncontrolled conditions. the highest levels of protection against z. subfasciatus were observed in arc1, with reduction in the number of eggs, number of emerged adults and percentage of damaged seeds than in arc3 and carioca cultivar. the number of eggs, number of emerged adults and the percentage of damaged seeds were reduced when the seeds were treated with malathion, neem and soybean oils. there was not difference in percentage of damaged seeds between malathion and neem oil. the treatment of the seeds using ant hill ground showed low efficiency, and trashing residues and dolomitic lime did not show reduction on the progeny and damage of z. subfasciatus.
Estabilidade da resistência a Zabrotes subfasciatus conferida pela proteína arcelina, em feijoeiro
BARBOSA, FLáVIA RABELO;YOKOYAMA, MASSARU;PEREIRA, PEDRO ANT?NIO ARRAES;ZIMMERMANN, FRANCISCO JOSé PFEILSTICKER;
Pesquisa Agropecuária Brasileira , 2000, DOI: 10.1590/S0100-204X2000000500005
Abstract: arcelin is a seed protein found in beans which gives resistance to mexican bean weevil, zabrotes subfasciatus (boh., 1833) (coleoptera: bruchidae). compared with the susceptible cultivars porrillo 70 and goiano precoce, the stability of the resistance conferred by two alleles of the protein arcelin was observed in lines arc1 and arc4 after raising the insects for four consecutive generations feeding in the same genotype. the experiment was carried out at embrapa-centro nacional de pesquisa de arroz e feij?o (cnpaf), at santo ant?nio de goiás, goiás state, brazil, under non-controlled conditions using a randomized complete block design. in the lines containing arcelin reduction in the number of eggs and emerged adults, insects weight and elongation of the egg/adult cycle was observed. the resistance was greater in the line carrying arc1 allele. the parameters number of eggs and emerged adults, egg/adult cycle, sexual ratio and males weight was not altered on arc1 genotype, although a progressive increase of the females weight was observed. on the genotype containing arc4 allele there was a reduction in the egg/adult cycle, although the number of eggs and emerged adults, sexual ratio and males and females weight were not altered.
Efeito da proteína arcelina na biologia de Zabrotes subfasciatus (Boheman 1833), em feijoeiro
Barbosa, Flávia Rabelo;Yokoyama, Massaru;Pereira, Pedro Ant?nio Arraes;Zimmermann, Francisco José Pfeilsticker;
Pesquisa Agropecuária Brasileira , 1999, DOI: 10.1590/S0100-204X1999001000006
Abstract: arcelin is a seed protein found in wild beans (phaseolus vulgaris) which gives resistance to mexican bean weevil, zabrotes subfasciatus (boheman 1833) (coleoptera: bruchidae). studies were carried out with the objective of estimating the effect of four alleles of protein arcelin (arc1, arc2, arc3 and arc4) on the biology of z. subfasciatus. the experiment was carried out in laboratory at embrapa-centro nacional de pesquisa de arroz e feij?o, in santo ant?nio de goiás, go, brazil, under non controlled conditions. the highest levels of antibiosis to z. subfasciatus were observed in arc1, with reduction in the number of eggs, number of emerged adults, adults longevity. in the line arc2 only reduction in the number of emerged adults was observed. the lines arc3 and arc4 showed low efficiency on the reduction of progeny of z. subfasciatus and effects in the longevity and egg-adult cycle were not detected. insect sexual ratio was not altered by the presence of arc1, arc2, arc3 and arc4 in the seeds.
Controle do caruncho-do-feijoeiro Zabrotes subfasciatus com óleos vegetais, munha, materiais inertes e malathion
Barbosa Flávia Rabelo,Yokoyama Massaru,Pereira Pedro Ant?nio Arraes,Zimmermann Francisco José Pfeilsticker
Pesquisa Agropecuária Brasileira , 2002,
Abstract: Na busca de alternativas ao controle químico do caruncho Zabrotes subfasciatus (Coleoptera:Bruchidae), avaliou-se, em feijoeiro (Phaseolus vulgaris L.), o efeito de três genótipos, cv. Carioca e duas linhagens contendo a proteína arcelina (Arc1 e Arc3), e da adi o nos gr os armazenados de óleo de soja (Glycine max Merrill); óleo de nim (Azadirachta indica A. Juss.), munha (resíduo de trilha da colheita), calcário dolomítico e terra de formigueiro, comparativamente aos gr os n o tratados e ao controle químico com malathion 500 CE. O experimento foi realizado no laboratório da Embrapa-Centro Nacional de Pesquisa de Arroz e Feij o, localizado no Município de Santo Ant nio de Goiás, GO, em condi es n o controladas. Na linhagem Arc1, constatou-se maior prote o aos danos do caruncho, observando-se redu o do número de ovos e de adultos emergidos e da porcentagem de sementes danificadas em rela o à Arc3 e à cv. Carioca. Quando os gr os foram tratados com malathion, óleo de nim e óleo de soja, observou-se menor número de ovos e de adultos emergidos e redu o de danos, e n o houve diferen a na porcentagem de sementes danificadas entre o malathion e o óleo de nim. A mistura das sementes com terra de formigueiro conferiu baixa prote o ao caruncho, enquanto os tratamentos com munha e calcário dolomítico n o apresentaram eficiência na redu o da progênie e dos danos de Z. subfasciatus.
Estabilidade da resistência a Zabrotes subfasciatus conferida pela proteína arcelina, em feijoeiro
BARBOSA FLáVIA RABELO,YOKOYAMA MASSARU,PEREIRA PEDRO ANT?NIO ARRAES,ZIMMERMANN FRANCISCO JOSé PFEILSTICKER
Pesquisa Agropecuária Brasileira , 2000,
Abstract: A arcelina é uma proteína encontrada em feij es silvestres e confere resistência ao caruncho-do-feij o, Zabrotes subfasciatus (Boh., 1833) (Coleoptera: Bruchidae). Comparativamente às cultivares suscetíveis Porrillo 70 e Goiano Precoce, estudou-se a estabilidade da resistência, conferida por dois alelos da proteína arcelina, nas linhagens do feijoeiro Arc1 e Arc4, após a cria o do inseto por quatro gera es sucessivas no mesmo genótipo. O experimento foi conduzido no Laboratório da Embrapa-Centro Nacional de Pesquisa de Arroz e Feij o (CNPAF), no município de Santo Ant nio de Goiás, GO, em condi es n o-controladas, utilizando-se delineamento experimental inteiramente ao acaso. Observaram-se, nas linhagens portadoras de arcelina, redu o do número de ovos e de adultos emergidos, redu o do peso dos insetos, e prolongamento do período ovo-adulto. Na linhagem Arc1, a resistência ao Z. subfasciatus foi mais expressiva. Nessa linhagem, os parametros número de ovos, número de adultos emergidos, período ovo-adulto, raz o sexual e peso de machos n o foram alterados, porém observou-se aumento progressivo de peso das fêmeas nas gera es. Na linhagem Arc4, houve redu o do período ovo-adulto, embora o número de ovos e de adultos emergidos, raz o sexual e peso de machos e fêmeas n o tenham sido alterados.
Agent-based Ecological Model Calibration - on the Edge of a New Approach
Antonio Pereira,Pedro Duarte,Luis Paulo Reis
Computer Science , 2008,
Abstract: The purpose of this paper is to present a new approach to ecological model calibration -- an agent-based software. This agent works on three stages: 1- It builds a matrix that synthesizes the inter-variable relationships; 2- It analyses the steady-state sensitivity of different variables to different parameters; 3- It runs the model iteratively and measures model lack of fit, adequacy and reliability. Stage 3 continues until some convergence criteria are attained. At each iteration, the agent knows from stages 1 and 2, which parameters are most likely to produce the desired shift on predicted results.
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