Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Filtros aplicados
Intervalo de ano de publicação
1.
Biosci. j. (Online) ; 38: e38013, Jan.-Dec. 2022. tab
Artigo em Inglês | LILACS | ID: biblio-1361651

RESUMO

This research was aimed at obtaining varieties of soybean adaptive to acid soils and to obtain Plant Growth-Promoting Rhizobacteria (PGPR) isolates that can improve the agronomic characteristics of soybean and increase the ultisols fertility. This research was conducted in two-stages research on Sampali Village, Percut Sei Tuan sub-District, Deli Serdang District, North Sumatra Province, Indonesia from August 2019 until March 2020. The first stage (adaptive varieties screening) using the non-factorial Randomized Block Design (RBD) with the varieties of Argomulyo, Wilis, Kaba, Dena-1, Devon-1, Dega-1, Demas-1, Burangrang, Detam-1, and Kipas Merah. The second stage (application of PGPR isolates singly and in combinations) using the factorial RBD, the first factor of applicative single and the combination of PGPR isolates, the second factor of adaptive varieties including Detam-1 and Wilis. Data were analyzed with ANOVA and followed by DMRT at P<0.05. The results showed that the Detam-1 and Wilis varieties had significantly higher yield per plant of 14.73 g and 14.54 g, respectively, than other varieties. The applications of a single and combination of PGPR isolates significantly increased the number of branches, stem diameter, plant height, yield per plant, soil pH, organic-C, available-P, and total-N and decreased the soil C/N. The Detam-1 variety had the higher in yield per plant compared to Wilis variety. The isolates combination of Rhizobium leguminosarum+Rhizobium sp2+Bacillus sp+Burkholderia sp for Detam-1 and Wilis varieties can be recommended to support the growth and yield of soybean on ultisols.


Assuntos
Rhizobium , Soja/crescimento & desenvolvimento , Acidez do Solo , Bactérias Fixadoras de Nitrogênio
2.
Rev. biol. trop ; 67(1): 94-106, Jan.-Mar. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1041897

RESUMO

Resumen Para los próximos 100 años se pronostica un incremento en la temperatura del planeta de casi 4 °C, lo cual pondrá en riesgo las especies que no logren adaptarse. En esta investigación se determinaron las respuestas morfofisiológicas de F. mexicana y los cambios en la población de bacterias fijadoras de nitrógeno atmosférico (BFN) asociadas a sus raíces, debido a dos condiciones ambientales con diferencias medias de temperatura de 5.1 oC: invernadero (temperatura alta, TA) y campo abierto (temperatura baja, TB); y con cuatro tratamientos: sin inocular (T), inoculadas con la cepa ocho (CP8), cepa cuatro (CP4) y con ambas cepas (CP8 + 4). Las BFN fueron aisladas de la rizosfera de F. mexicana y transformadas genéticamente con reporteros, para cuantificar la población al final del experimento. Se midió el peso seco de la parte aérea y la raíz, la tasa de asimilación de CO2 (A), el inicio de la floración, el número de flores y frutos; y la persistencia de las bacterias fijadoras de N atmosférico (BFN). Además, se evaluó la concentración de NO3, NH4, P y materia orgánica (MO) en el sustrato, al inicio y final del experimento. Las plantas sometidas a alta temperatura presentaron mayor peso seco de la parte aérea y fotosíntesis; con una disminución en el peso seco de la raíz, y en el número de flores y frutos. La MO en el sustrato disminuyó, mientras que la disponibilidad de NO3, NH4 y P aumentó. El incremento de temperatura y la mayor presencia de N en el substrato provocaron reducción en la población de BFN. Estos resultados sugieren que temperaturas altas estimulan el crecimiento de F. mexicana y tienen un impacto negativo sobre su reproducción y en las BFN asociadas a sus raíces.(AU)


Abstract The earth could experience a warming of 4 °C in the next one hundred years. This would put at risk the plants that can´t adapt. Fragaria mexicana is an endemic plant of temperate forest of Mexico. The response of this wild strawberry to temperature increasing has not been studied and could play an important role for event of global warming. This study determinate the morphological and physiological responses of F. mexicana and changes in the N2-fixing bacteria (BFN) population on its roots, due to two environmental conditions with differences of temperature 5.1 °C: greenhouse (high temperature, TA) and open land (low temperature, TB); and with four free-living nitrogen-fixing bacteria (BFN) treatments: non-inoculated (T), inoculated with strain eight (CP8), strain four (CP4), and strains eight and four mixed (CP8 + 4). BFN were isolated from the rhizosphere of F. mexicana and were genetically transformed with reporters to quantify the population at the end of the experiment. NO3, NH4 and P and organic matter (MO) in the substrate were determined at beginning and finish of the experiment. Shoot and root dry weight, photosynthetic rate, flowering and fructification starting, flowers and fruits number, were measured. Shoot dry weight and photosynthetic rate were lower in TB than TA, decreasing 3.1 g and 0.94 µmol m-2 s-1, respectively. Root dry weight was 3.0 g less in TA compared with TB. Number flowers decrease in 40.89 % and number fruits in 38.11 % on TA than TB. F. mexicana plants start flowering 14 days previously in TB than TA. MO in the substrate decrease in TA, while the concentration of NO3, NH4 and P, increased. Population of BFN was lower in TA. Results obtained indicated that higher temperature promotes the growth of F. mexicana and reduce its reproduction and BNF population associated with its roots.(AU)


Assuntos
Fotossíntese , Matéria Orgânica , Aquecimento Global , Bactérias Fixadoras de Nitrogênio , México
3.
Arq. bras. med. vet. zootec. (Online) ; 69(4): 1039-1046, jul.-ago. 2017. graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-876942

RESUMO

The objective of this study is to verify the population density and the dynamics of tillering in the Marandu palisade grass sward subjected to nitrogen (N) fertilization strategies, characterized by the N supply via urea or bacterial inoculant (Azospirillum brasilense). The treatments comprised of four nitrogen fertilization strategies: (A) Without fertilization, (B) 80 kg N/ha, (C) inoculant (A. brasilense), and (D) 80 kg N/ha + inoculant, distributed in a randomized complete block design, with three replications. The nitrogen supply strategies were evaluated during six periods: October, November, and December (2012) as well as January, March, and April (2013). The nitrogen dose or inoculant had no effect on the tiller appearance rate (TAR), tiller mortality rate (TMR), tiller survival rate (TSR), or tiller population density (TPD). However, these variables were influenced by the season. The TAR and TSR were higher at the beginning of the experimental period (October) and lower towards the end of the period (March-April), whereas, TMR and TPD exhibited the opposite behavior, with lower values in October and higher from January onward. Neither the nitrogen nor the inoculant influenced the population dynamics of the tillers in Marandu palisade grass.(AU)


Objetivou-se com este estudo verificar a densidade populacional e a dinâmica do perfilhamento em dosséis de capim Marandu submetidos a estratégias de adubação nitrogenada, caracterizadas pelo fornecimento de N via ureia ou inoculante (Azospirillum brasilense). Os tratamentos foram quatro estratégias de adubação nitrogenada: sem fertilização, 80kg N/ha, inoculante (A. brasilense) e 80kg N/ha + inoculante, distribuídos em um delineamento de blocos completos ao acaso, com três repetições por tratamento. As estratégias de aporte nitrogenado foram avaliadas em seis épocas: outubro, novembro e dezembro de 2012; e janeiro, março e abril de 2013. Não foi verificada influência da dose de nitrogênio ou do inoculante sobre a taxa de aparecimento (TAP), a taxa de mortalidade (TMP), a taxa de sobrevivência (TSP) e a densidade populacional de perfilhos (DPP). No entanto, essas variáveis foram influenciadas pela época do ano. A TAP e a TSP apresentaram maiores valores no início do período experimental (outubro) e menor valor ao final do período (março a abril). A TMP e a DPP expressaram respostas opostas, com menores valores em outubro e maiores a partir de janeiro. Não houve influência do nitrogênio e do inoculante sobre a dinâmica populacional de perfilhos em capim Marandu.(AU)


Assuntos
Azospirillum brasilense , Brachiaria , Fixação de Nitrogênio , Bactérias Fixadoras de Nitrogênio , Pastagens
4.
Braz. j. microbiol ; 48(1): 95-100, Jan.-Mar. 2017. tab
Artigo em Inglês | LILACS | ID: biblio-839348

RESUMO

Abstract The family Leguminosae comprises approximately 20,000 species that mostly form symbioses with arbuscular mycorrhizal fungi (AMF) and nitrogen-fixing bacteria (NFB). This study is aimed at investigating and confirming the dependence on nodulation and biological nitrogen fixation in the specie Piptadenia gonoacantha (Mart.) Macbr., which belongs to the Piptadenia group. Two consecutive experiments were performed in a greenhouse. The experiments were fully randomized with six replicates and a factorial scheme. For the treatments, the two AMF species and three NFB strains were combined to nodulate P. gonoacantha in addition to the control treatments. The results indicate this species’ capacity for nodulation without the AMF; however, the AMF + NFB combinations yielded a considerable gain in P. gonoacantha shoot weight compared with the treatments that only included inoculating with bacteria or AMF. The results also confirm that the treatment effects among the AMF + NFB combinations produced different shoot dry weight/root dry weight ratios. We conclude that AMF is not necessary for nodulation and that this dependence improves species development because plant growth increases upon co-inoculation.


Assuntos
Micorrizas , Bactérias Fixadoras de Nitrogênio , Fabaceae/microbiologia , Simbiose , Nódulos Radiculares de Plantas/microbiologia , Nodulação , Fixação de Nitrogênio
5.
Arq. bras. med. vet. zootec ; 68(5): 1360-1368, set.-out. 2016. tab
Artigo em Português | LILACS, VETINDEX | ID: biblio-827882

RESUMO

O objetivo do trabalho foi avaliar as características produtivas e nutricionais do capim- xaraés inoculado com bactérias diazotróficas associativas, em primeiro cultivo em Latossolo Vermelho do Cerrado. O experimento foi realizado em casa de vegetação. O delineamento experimental foi inteiramente ao acaso, constituído por fatorial 6x3: três estirpes de bactérias diazotróficas associativas (MTAz8, MTH2 e Y2), uma combinação das estirpes MTAz8 e MTH2, adubação nitrogenada e testemunha absoluta, e três cortes (30, 60 e 90 dias), em cinco repetições. A inoculação foi feita por meio da inserção de uma alíquota de 5mL de caldo bacteriano contendo 108 células mL-1 no solo próximo ao sistema radicular. As variáveis avaliadas foram: massa seca da parte aérea, porcentagem de proteína bruta, acúmulo e concentração de nitrogênio na parte aérea e determinação do número de bactérias diazotróficas do solo. No tratamento adubado com nitrogênio, a produção de massa seca aumentou ao longo dos cortes. Entre as estirpes de bactérias associativas, a Y2 apresentou maior acúmulo de nitrogênio e maior população de bactérias no meio de cultura LGI. As características nutricionais do capim-xaraés decaíram à medida que foram realizados os cortes.(AU)


The aim of this study was to evaluate yield and nutritional characteristics of Xaraés grass inoculated with diazotrophic associative bacteria in the first cultivation in the Cerrado Oxisol. The experiment was conducted in the greenhouse. The experimental design was completely randomized factorial 6x3 consisting of: three strains of diazotrophic associative bacteria (MTAz8, MTH2 and Y2), a combination of strains MTAz8 and MTH2, nitrogen fertilization and absolute control, and three cuts (30, 60 and 90 days) in five replicates. The inoculation was performed by inserting an aliquot of 5ml of the bacterial broth containing 10 8 cells ml-1 in the soil near the root zone of each plant. The variables evaluated were: dry weight of shoot, crude protein, accumulation and nitrogen concentration in the shoot and determining the number of nitrogen-fixing bacteria in the soil. The fertilized soil dry matter production increased over the cuts. Among the strains Y2 showed higher accumulation of nitrogen and largest population of bacteria in the middle of the LGI culture. The nutritional characteristics of Xaraés grass declined as the cuts were made.(AU)


Assuntos
Brachiaria/crescimento & desenvolvimento , Bactérias Fixadoras de Nitrogênio , Pastagens/análise , Fixação de Nitrogênio
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...