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Crescimento e produ??o de feijoeiro originado de sementes com diferentes teores de f?sforo e molibd?nio sob diferentes fontes de nitrog?nio. / Growth and yield of common bean originated from seeds with different concentrations of phosphorus and molybdenum at different nitrogen sources.Pacheco, Rafael Sanches 10 August 2010 (has links)
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Previous issue date: 2010-08-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico, CNPq, Brasil. / Nutrient concentration in the seeds can affect the initial development, biological nitrogen
fixation (BNF) and yield of plants. Common bean (Phaseolus vulgaris L.) has been
considered as a species with low capacity of BNF as compared to other grain legumes, but
results demonstrate the potential of BNF to supply the N demand of the crop and to achieve
adequate yields. The objective of this study was to evaluate the effect of seed concentrations
of Mo and P on biomass production, nodulation and grain yield of common bean at different
sources of N supply. The field experiment was conducted between April and July 2009, in the
Santa Monica Farm of Embrapa Gado de Leite in the municipality of Valen?a ? Rio de
Janeiro State. The experimental design was a split-plot 4x4 factorial randomized block with 5
replicates. The main plots consisted of four N sources: control without N, mineral N
fertilization with 20 kg N ha-1 at sowing + 40 kg N ha-1 in cover, inoculation with the
commercial strain of rhizobia, rhizobia inoculation + 40 kg N ha-1 in cover. The subplots
consisted of four combinations between concentrations of P and Mo in the seeds (low P low
Mo, low P high Mo, Mo high P low, high-P high-Mo). The seeds of cultivar Carioca were
originating from a field experiment when 5 kg P ha-1 and 120 g Mo ha-1 were foliar sprayed at
52 and 71 days after emergence (DAE). In each subplot, plant biomass were sampled at 30, 42
and 57 DAE, and root, shoot and nodules dry mass, the number of nodules and the
accumulation of N in the shoot were determined. Grains were harvested at 90 DAE, and grain
yield, yield components, N and Mo concentratios in the grains were measured. Interactions
between the N sources and the concentrations of P and Mo in the seeds were not significant in
the three sampling times, except for shoot dry mass and number of nodules at 57 DAE. Seeds
with low P and high Mo increased shoot dry matter and grain yield of beans. Mineral N
fertilizer increased root mass in the early growth stages. The rhizobia inoculation increased
bean nodulation. There was a small effect of the seeds with high P concentration in the
accumulation of N and mass of shoots at 57 DAE. Mineral N fertilizer increased N
accumulation in the shoots at 57 DAE. The inoculation + 40 kg N ha-1 in cover gave similar
grain yield and N accumulation as the application of 60 kg N ha-1, both treatments superior to
the control. The use of seeds enriched with P and Mo, associated with the inoculation of seeds
and the application of N in cover, could maximize the process of biological nitrogen fixation
in the common bean crop. / A concentra??o de nutrientes nas sementes pode afetar o desenvolvimento inicial, a fixa??o
biol?gica de nitrog?nio (FBN) e a produ??o de gr?os das plantas por elas geradas. O feijoeiro
(Phaseolus vulgaris L.) tem sido considerado uma esp?cie de baixa capacidade de FBN em
compara??o com outras leguminosas de gr?o, mas resultados demonstram o potencial da FBN
em suprir a demanda de N do feijoeiro e obter boas produtividades. O objetivo deste estudo
foi avaliar o efeito dos teores de P e Mo em sementes na produ??o de biomassa, nodula??o e
no rendimento de gr?os de feijoeiro sob diferentes fontes de fornecimento de N. O
experimento foi conduzido em condi??es de campo entre abril e julho de 2009, na Fazenda
Santa M?nica da Embrapa Gado de Leite, no munic?pio de Valen?a ? RJ, em delineamento
em blocos ao acaso em fatorial 4x4 com 5 repeti??es em parcelas subdivididas. As parcelas
foram compostas por quatro fontes de N: testemunha absoluta sem N; aduba??o com N
mineral com 20 kg N ha-1 no plantio + 40 kg N ha-1 em cobertura; inocula??o com a estirpe
comercial de riz?bio recomendada para a cultura; inocula??o com estirpe comercial + 40 kg N
ha-1 em cobertura. As subparcelas foram compostas por quatro combina??es entre teores de P
e de Mo na semente (baixo P baixo Mo, baixo P alto Mo, alto P baixo Mo, alto P alto Mo). As
sementes da cultivar Carioca utilizadas foram oriundas de um experimento de campo onde
foram efetuadas aplica??es foliares com 5 kg P ha-1 e 120 g Mo ha-1 aos 52 e 71 dias ap?s
emerg?ncia (DAE). Em cada subparcela foram efetuadas tr?s amostragens de biomassa, aos
30, 42 e 57 DAE, determinando-se a massa seca de raiz, parte a?rea e n?dulos, o n?mero de
n?dulos e a acumula??o de N na parte a?rea. A colheita de gr?os foi efetuada aos 90 DAE,
determinando-se o rendimento de gr?os, os componentes de produ??o e o teor de N e de Mo
nos gr?os. As intera??es entre as fontes de N e os teores de P e Mo das sementes, nas tr?s
?pocas de coleta, n?o foram significativas, exceto para massa seca de parte a?rea e n?mero de
n?dulos aos 57 DAE. As sementes com baixo P e alto Mo foram as que promoveram maior
massa de parte a?rea e tamb?m a maior produ??o de gr?os de feij?o. A aduba??o com N
mineral promoveu maior massa radicular nos est?gios iniciais de crescimento. A inocula??o
das sementes com riz?bio aumentou a nodula??o do feijoeiro. Houve um pequeno efeito dos
altos teores de P nas sementes na acumula??o de N e de biomassa da parte a?rea aos 57 DAE.
A aplica??o de N mineral promoveu maior ac?mulo da N na parte a?rea aos 57 DAE. A
inocula??o combinada com 40 kg N ha-1 em cobertura forneceu rendimento de gr?os e
acumula??o de N nos gr?os similar ? aplica??o de 60 kg N ha-1, por sua vez superiores ?
testemunha. O uso de sementes enriquecidas com P e Mo, associada com a inocula??o de
sementes e a aplica??o de N em cobertura, podem maximizar o processo de fixa??o biol?gica
de nitrog?nio na cultura do feijoeiro.
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Estoque de carbono, nitrog?nio e fertilidade do solo em ?reas em recupera??o com leguminosas e em sistema de agricultura itinerante de alta produtividade . / Soil carbon and nitrogen stocks and fertility in areas in recuperation with leguminous trees and on shifting cultivation system area with high productivity.Macedo, Michele de Oliveira 31 July 2007 (has links)
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Previous issue date: 2007-07-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / This study aimed to evaluate carbon and nitrogen stocks restoration, and soil fertility status in
land reclamation with nodulated and mycorrhizal legume trees and fallow length on high
productivity shifting cultivation. Evaluations were made of soil C and N stocks, concentration
of free and occluded light fraction and soil available Ca, Mg, P, K, C and N, and amounts of
mass and nutrients of litter in the dry and rainy season. One of the areas located in Angra dos
Reis, RJ is under reclamation for 13 years. As reference area it was used a forest fragment and
deforested area nearby. A second area is located in Serop?dica, RJ, and it is under reclamation
for 17 years with the species Acacia auriculiformis and Mimosa caesalpiniifolia, and with
Albizia guachapele for 13 years. As reference area it was used a secondary forest fragment
and a pasture area. Both areas under recuperation in Angra dos Reis and in Serop?dica had
been used as source of topsoil, having lost part of the upper soil horizons. The slash-and-burn
area is located in Bom Jardim, Nova Friburgo, RJ. For this study, it was utilized a
chronossequence of soil gradient: area cultivated for one year; area cultivated with crop
rotation for three years; area cultivated with bananas for 18 years; area under fallowing for
five years; and others two fallowing areas for 18 and 33 years. The usage of legume trees in
land reclamation was able to increase stocks of C and N, from 0.04 to 0.15 Mg ha-1 year-1 for
N, and of 0.13 to 1.73 Mg ha-1 year-1 for C. In the slash-and-burn agriculture system, the
lowest soil C stock was found in the one and three years cultivated areas. The highest stock
was observed under fallowing and in the area planted with bananas, and they were similar
between areas. The highest soil N stock was found in fallow with five years. In Angra dos
Reis area the concentration of free and occluded light fraction was similar between areas of
forest and under reclamation. In Serop?dica, only the free light fraction of organic matter was
re-established. There was no significant difference between the concentrations of free and
occluded light fraction in Bom Jardim areas; however, the area with five years fallow and
three years cultivation showed the same values of the free light fraction. In Angra dos Reis
areas, the litter stocks were similar between the forest and the area under reclamation. In
Serop?dica, except for the area under A.auriculiformis with greatest litter stock, all other areas
showed similar litter stocks. In Bom Jardim, the litter stocks were similar among the
fallowing areas. The nutrients contained in the litter, in general, were similar among the areas,
and they were dependent on the litter mass. The soil fertility in the areas under reclamation
was slightly higher than in the reference ones. In the slash-and-burn area, the soil fertility
analyses indicated a residual effect of liming in the fallow with five years. Considering the
attributes soil fertility and soil C and N stocks, the best fallowing period would be of five
years. / Neste estudo foi avaliado o potencial do uso de leguminosas arb?reas fixadoras de nitrog?nio,
e da utiliza??o de pousio em um sistema de agricultura itinerante de alta produtividade, em
restabelecer a ciclagem de nutrientes e incrementar os estoques de C e N. Foram avaliados os
estoques de C e N do solo, as concentra??es de fra??o leve livre e leve oclusa da mat?ria
org?nica, os teores de Ca, Mg, P, K, C e N no solo, e o estoque e a quantidade de nutrientes
presentes na serapilheira nas esta??es seca e chuvosa. Uma das ?reas avaliadas, no munic?pio
de Angra dos Reis (RJ), est? em recupera??o h? 13 anos. Para fins de compara??o, utilizou-se
como refer?ncia uma ?rea de mata e outra, desmatada, adjacente ? ?rea em recupera??o. As
demais ?reas estudadas localizam-se em Serop?dica (RJ), e est?o em recupera??o h? 17 anos
com as esp?cies Mimosa caesalpiniifolia e Acacia auriculiformis, e h? 13 anos, com a esp?cie
Albizia guachapele. Como ?rea refer?ncia foi utilizada uma ?rea de capoeira e outra de
pastagem. Tanto a ?rea em recupera??o localizada em Angra dos Reis quanto as ?reas em
recupera??o em Serop?dica haviam sido utilizadas como ?reas de empr?stimo, tendo perdido
parte dos horizontes superficiais do solo. A ?rea de agricultura itinerante situa-se em Bom
Jardim, regi?o serrana do Rio de Janeiro. Foi avaliado um gradiente de uso do solo: ?rea
cultivada h? um ano; ?rea h? tr?s anos com rota??o cultivos; ?rea h? 18 anos cultivada com
bananas; ?rea em pousio h? cinco anos; e outras duas ?reas em pousio h? 18 e 33 anos. O uso
de leguminosas incrementou os estoques de C e N do solo nas ?reas em recupera??o. As taxas
de aumento variaram de 0,04 a 0,15 Mg ha-1 ano-1 para N, e de 0,13 a 1,73 Mg ha-1 ano-1 de C.
No sistema de agricultura itinerante, os menores estoques de C foram observados nas ?reas
cultivadas h? um e h? tr?s anos. Nas ?reas em pousio e no bananal os estoques foram
similares entre si e superiores aos das ?reas cultivadas. O maior estoque de N foi observado na
?rea com cinco anos de pousio. As concentra??es de fra??o leve livre e leve oclusa foram
similares entre as ?reas de mata e em recupera??o em Angra dos Reis. Nas ?reas em
recupera??o em Serop?dica, somente a fra??o leve livre foi restabelecida. J? nas ?reas de Bom
Jardim, n?o houve diferen?a significativa entre as concentra??es de fra??o leve livre e leve
oclusa. No entanto, o pousio de cinco anos e o cultivo de tr?s anos apresentaram os menores
valores de fra??o leve livre. Os estoques de serapilheira nas ?reas de mata e em recupera??o
de Angra dos Reis foram similares. As ?reas em recupera??o no munic?pio de Serop?dica
apresentaram estoques de serapilheira similares, com exce??o da esp?cie A. auriculiformis
que mostrou os maiores estoques. Nas ?reas em pousio do sistema de agricultura itinerante, os
estoques de serapilheira foram similares. O estoque de nutrientes da serapilheira, em geral,
variou pouco, e foi dependente da massa de serapilheira. A fertilidade dos solos das ?reas em
recupera??o foi ligeiramente maior que das ?reas refer?ncia. Na agricultura itinerante, pode-se
observar efeito residual da calagem usada pelo agricultor no pousio de cinco anos. De acordo
com os resultados de estoque de C, N e fertilidade do solo, o per?odo de pousio mais indicado
para o corte e queima foi o de cinco anos.
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Avalia??o de um sistema agroflorestal com a?a?, mogno africano e leguminosas arb?reas implantado h? 10 anos em Serop?dica, RJ / Evaluation of an agroforestry system with a?a?, african mahogany and leguminous trees implanted 10 years ago in Serop?dica, RJOLIVEIRA, David Castor Maxwel 24 October 2016 (has links)
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Previous issue date: 2016-10-24 / Agroforestry systems (ASF) are potentially characterized as a agroecological crops by the similarity to the forest structure and function which gives more sustainability to the production systems, making them environmentally friendly. This study evaluated an AFS ten years plantation to obtain information about the nitrogen fixing legumes influenced over the soil chemical properties, the palm heart production, the Khaya ivorensis A. Chevalier and Euterpe oleracea Mart. Growth, and finally the common beans cultivation. The AFS was located at Embrapa Agrobiologia Experimental field, at Serop?dica city, Rio de Janeiro state. The statistical was randomized blocks with 5 treatments and 4 replications with 9 m x 9 m plots and total area with 1.620 m2. There were E. oleraceae, planted in a 3 m x 3 m spacing with one plant of K. ivorensis at the plot center. The treatments were different kinds of green manure crops between the lines such as: Acacia angustissima (Mill.) Kuntze; Gliricidia sepium (Jacq.) Steud;. Canavalia ensiformis (L.) DC, nitrogen fertilization with castor cake and spontaneous vegetation. For the soil fertility analyses were collected two samples, one before and other after green manure crops management. K. ivorensis and E. oleraceae biometry, also heart palm production were harmed by inappropriate management on cultivation care lack between post planting and this evaluation lapse. These commercial crops reached larger diameters and superior height at the plot without leguminous crops competition. Green manure crops were efficient in soils nutrients cycling, increasing the most elements content after pruning the leguminous plants and the application of the biomass over the ground. Extract nodules inoculation showed capacity to increase nodulation and nitrogen content in common beans plants, but didn?t increase the grain production. / Os sistemas agroflorestais (SAF) podem ser configurados como cultivos agroecol?gicos, onde a similaridade com as florestas em estrutura e fun??o confere ao sistema uma maior sustentabilidade, tornando-os ambientalmente adequados. Este estudo avaliou um SAF com 10 anos de implanta??o, gerando informa??es sobre quanto as culturas de leguminosas fixadoras de nitrog?nio influenciaram nas propriedades qu?micas do solo e na produ??o do sistema, quantificando a produ??o de palmito, o crescimento de plantas de Khaya ivorensis A. Chevalier e Euterpe oleracea Mart. plantados e o cultivo de feij?o. O experimento estava localizado no Campo Experimental da Embrapa Agrobiologia, no munic?pio de Serop?dica, do Rio de Janeiro. O delineamento experimental adotado foi o de blocos ao acaso com cinco tratamentos e quatro repeti??es, com parcelas de 9 m x 9 m cada, totalizando 1.620 m2. Em todos os tratamentos existiam a?a?s plantados de 3 m x 3 m ao longo de todas as parcelas que tamb?m continham um mogno africano no centro de cada uma. Os tratamentos foram compostos por aduba??es verdes nas entrelinhas dos a?a?s, constitu?dos por Acacia angustissima (Mill.) Kuntze; Gliricidia sepium (Jacq.) Steud.; p aduba??o nitrogenada de cobertura com torta de mamona e o controle com vegeta??o espont?nea. Para avalia??o qu?mica do solo foram feitas duas coletas, uma antes e outra p?s manejo da biomassa vegetal. Foi realizada a biometria das plantas de mogno africano, de a?a?, e a quantifica??o da produ??o de palmito, onde foi poss?vel perceber que essas culturas tiveram o crescimento prejudicado devido a falta de manejo, tendo em vista que houve menos competi??o nas parcelas sem leguminosas arb?reas, onde essas culturas de interesse atingiram maiores di?metros e alturas, refletindo da mesma forma na produ??o de palmito. A aduba??o verde foi eficiente na ciclagem de nutrientes do solo, aumentando o teor da maioria dos elementos ap?s um manejo e superando vegeta??o espont?nea al?m de ter beneficiado a produ??o do feijoeiro. A inocula??o com extrato de n?dulos ? capaz de aumentar a nodula??o e o teor de nitrog?nio da parte a?rea do feijoeiro, por?m n?o aumentou a produ??o de gr?os.
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Estudo de associa??o entre bact?rias fixadoras de nitrog?nio e fungos micorr?zicos arbusculares associados a leguminosas do grupo das piptadenias / Study of association between nitrogen-fixing bacteria and arbuscular mycorrhizal fungi associated with legumes from the piptadenias groupOliveira Junior, Joel Quintino de 28 February 2014 (has links)
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Previous issue date: 2014-02-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Leguminosae comprises a wide variety of species that form symbiosis with mycorrhizal fungi (AMF), and mostly with nitrogen fixing bacteria. Within this frame fits the group Pitadenia encompassing genres: Mimosa , Piptadenia , Parapiptadenia , Anadenathera , Pseudopiptadenia , Microlobius , Stryphnodendron and Adenopia , comprising over 500 species, of which most are found in the New World , especially in Brazil . Their habits vary from tree and herbaceous species to thrive in flooded, dry, high altitude grasslands , savanna ecosystems among other areas . Are well known and used in the rehabilitation of degraded soils by their aggressiveness and ability to grow under adverse soil conditions. Results indicate that in some species of this group only nodulated with the presence of mycorrhizal fungi. Legumes use for the realization of these two symbioses very similar molecular mechanisms and some of leguminous species from the subfamily Mimosoideae show atypical and high potential exploration of evolutionary symbiosis between the two skills. The objective of this work is to investigate and confirm this dependence of the presence of arbuscular mycorrhizal fungi for nodulation and nitrogen fixation in species group Piptadenia nodulated by Burkholderia sp . under controlled conditions / A fam?lia Leguminosae compreende um imensa variedade de esp?cies que formam simbiose com fungos micorr?zicos arbusculares (FMAs) e, em sua grande maioria, com bact?rias fixadoras de nitrog?nio. Dentro desse quadro se encaixa o grupo de Pitadenia que engloba os g?neros: Mimosa, Piptadenia, Parapiptadenia, Anadenathera, Pseudopiptadenia, Microlobius, Stryphnodendron e Adenopia, compreendendo mais de 500 esp?cies, sendo que a maioria delas ? encontrada no novo mundo, em especial no Brasil. Seus h?bitos variam desde esp?cies herb?ceas at? arb?reas e se desenvolvem em ?reas alagadas, secas, campos de altitude, cerrado entre outros ecossistemas. S?o bem conhecidas e utilizadas na reabilita??o de solos degradados por sua agressividade e capacidade de se desenvolver nas mais adversas condi??es ed?ficas. Resultados indicam que em algumas esp?cies desse grupo s? nodulariam com a presen?a de fungos micorr?zicos. As leguminosas usam para a realiza??o dessas duas simbioses mecanismos moleculares muito similares e algumas dessas esp?cies de leguminosas nativas da subfam?lia Mimosoideae mostram habilidades at?picas e com alto potencial de explora??o evolucion?ria entre as duas simbioses. O objetivo deste trabalho ? investigar e confirmar essa depend?ncia da presen?a de fungos micorr?zicos arbusculares para a nodula??o e fixa??o biol?gica de nitrog?nio em esp?cies do grupo de Piptadenia noduladas por Burkholderia sp. sob condi??es controladas
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Monitoramento do estabelecimento das bact?rias presentes no inoculante da Embrapa Agrobiologia, durante o desenvolvimento inicial de plantas de cana-de-a??car utilizando t?cnicas microbiol?gicas e moleculares / Monitoring the establishment of bacteria in the inoculant of Embrapa Agrobiology, during the initial root development of sugarcane plants using microbiological and molecular techniquesCOSTA, Caroline Barra Sales Khayat da 26 July 2016 (has links)
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Previous issue date: 2016-07-26 / CAPES / One of the most known and important process in nature is the biological nitrogen fixation (FBN). Few classes of microorganisms perform this process; named diazotrophics that associated with plants is an important alternative to enhance nitrogen nutrition in agricultural systems. Diazotrophic bacterial population in association with sugarcane improves the yield due to its ability to colonize the inner roots of the host plant and do not provoke any pathogenicity signal. Quantitative analyzes have indicated that selection of combinations of endophytic diazotrophic strains when associated with sugarcane varieties can improve the yield and therefore varieties of sugarcane may be better exploited in order to benefit this association for agricultural purposes. Thus, this work proposes to monitor the establishment of diazotrophic bacteria present in the inoculant of Embrapa, during the initial development of sugarcane plants. Micro-propagated sets of the sugarcane variety RB867515 were inoculated individually and with a mixture of five nitrogen fixing bacteria strains that compose the sugarcane inoculant: Nitrospirillum amazonense (CBAmC) Paraburkholderia tropica (Ppe8) Gluconacetobacter diazotrophicus (Pal5) Herbaspirillum seropedicae (HRC54) and Herbaspirillum rubrisubalbicans (HCC103). Plants were grown in a greenhouse and harvested 30 days after planting. Fresh root material was separated for evaluation of the establishment of the strains by bacterial counting using the technique of Most Probable Number (MPN), absolute quantification by Real Time PCR (qPCR), besides the identification of the inoculated strains through analysis of the rDNA profile of the pellicle formed in the respective semisolid media using the BOX-PCR technique. The results of bacterial count diazotrophic present in the roots by NMP showed that the treatments inoculated in the control (native population) showed higher population of bacterial cells around 105 cells by fresh root mass, but not statistically significant. The methodology qPCR permitted quantitation of the number of 16S rDNA copies in the order of 105 bacterial cells g - 1 fresh weight root, showing that there were differences in the population of endophytic species that colonize the roots of sugarcane. The profiles of BOX -PCR of the respective pellicles formed in semisolid media did not show high similarity (> 80 %) with the profile of the species inoculated for most of the treatments. The results obtained indicate that the qPCR technique showed the establishment of some of the inoculated strains in sugar cane buds while the NMP technique showed no significant difference between treatments inoculated and non-inoculated possibly due to the lower sensitivity of the method. / Um dos processos mais conhecidos e importantes na natureza ? a fixa??o biol?gica de nitrog?nio atmosf?rico (FBN). Este processo ? realizado por algumas classes de microrganismos, denominados diazotr?ficos, que associados com esp?cies vegetais s?o uma alternativa importante para aprimorar a nutri??o nitrogenada nos sistemas agr?colas. As popula??es de bact?rias fixadoras de nitrog?nio atmosf?rico quando associadas ? cultura da cana-de-a??car melhoram a produ??o e, ao colonizarem o interior das ra?zes promovem benef?cios ?s plantas hospedeiras. An?lises quantitativas t?m indicado que a sele??o das combina??es de estirpes de bact?rias diazotr?ficas endof?ticas e variedades de cana-de-a??car podem ser melhor exploradas com o objetivo de aperfei?oar a associa??o para finalidades agr?colas. Assim, o presente trabalho prop?e monitorar o estabelecimento das bact?rias diazotr?ficas presentes no inoculante para cana-de- a??car da Embrapa, durante o desenvolvimento inicial planta. Toletes propagados da variedade RB867515 de cana-de-a??car foram inoculados individualmente e com a mistura das cinco estirpes de bact?rias diazotr?ficas: Nitrospirillum amazonense (CBAmC), Paraburkholderia tropica (PPe8), Gluconacetobacter diazotrophicus (Pal5), Herbaspirillum seropedicae (HRC54) e Herbaspirillum rubrisubalbicans (HCC103). As plantas foram crescidas em casa de vegeta??o e coletadas 30 dias ap?s o plantio, sendo separado o material vegetal para avalia??o do estabelecimento das estirpes pela t?cnica do N?mero Mais Prov?vel (NMP) e quantifica??o absoluta por PCR em Tempo Real (qPCR). Adicionalmente foi feita a identifica??o das estirpes inoculadas atrav?s da an?lise do perfil de rDNA das pel?culas bacterianas formadas nos respectivos meios semiss?lidos pela t?cnica de BOX-PCR. Os resultados obtidos da contagem de bact?rias diazotr?ficas presente nas ra?zes por NMP mostrou que os tratamentos inoculados em rela??o ao controle (popula??o nativa), apresentaram uma maior popula??o de c?lulas bacterianas em torno de 105 c?lulas por massa fresca de raiz, por?m n?o significativa. A metodologia de qPCR permitiu a quantifica??o do n?mero de c?pias do 16S rDNA, da ordem de 105 c?lulas bacterianas g-1 massa fresca de raiz, mostrando que houve diferen?a na popula??o das esp?cies diazotr?ficas endof?ticas que colonizam as ra?zes de cana-de-a??car. Os perfis obtidos por BOX-PCR das pel?culas formadas nos respectivos meios semiss?lidos n?o mostraram alta similaridade (>80%) com o perfil das esp?cies inoculadas para a maioria dos tratamentos inoculados. Os resultados obtidos indicam que a t?cnica de qPCR permitiu mostrar o estabelecimento de algumas estirpe do inoculante nos toletes de cana-de a??car enquanto que a t?cnica de NMP n?o mostrou diferen?a significativas entre os tratamentos inoculados e n?o inoculados possivelmente pela menor sensibilidade da metodologia.
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