RESUMO
A new species of Meliolinites (fossil Meliolaceae), M. buxi sp. nov., is reported from the Oligocene Ningming Formation of Guangxi, South China. The fungus has hyphopodia characteristics of extant Meliolaceae, such as thick-walled, branching hyphae with appressoria and phialides. However, these fossils entirely lack mycelial or perithecial setae and have only a few phialides, thereby distinguishing the new species from most known species. The fungus was discovered on the adaxial and abaxial cuticles of several fossilized Buxus leaves. Thickening and twisting of cell walls in the Buxus leaf cuticle, along with the parasitic feeding strategy of the extant Meliolaceae, suggest that a parasitic interaction between Buxus and M. buxi seems feasible. The distribution of modern Meliolaceae suggests that they live in warm, humid subtropical-tropical climates. It is possible that the presence of M. buxi indicates a similar climatic condition. The co-occurrence of large-leaf Buxus and floristic comparisons of the Ningming assemblage also corroborate this conclusion.
Assuntos
Ascomicetos/isolamento & purificação , Buxus/microbiologia , Fósseis/anatomia & histologia , Ascomicetos/classificação , Ascomicetos/crescimento & desenvolvimento , China , Hifas/classificação , Hifas/crescimento & desenvolvimento , Hifas/isolamento & purificação , Folhas de Planta/microbiologiaRESUMO
OBJECTIVE: To observe the effects of electroacupuncture pretreatment on postoperative cognitive dysfunction (POCD), neuronal apoptosis and neuron-inflammation in aged rats. METHODS: Thirty-six male SD rats aged 20 months were randomly divided into sham operation group, model group and electroacupuncture (EA) group, with 12 rats in each group. The POCD rats model was prepared by internal fixation of left tibial fracture. Five days before modeling, EA stimulation (2 Hz/15 Hz, 1 mA, 30 min) was applied to "Zusanli" (ST36), "Hegu" (LI4) and "Neiguan" (PC6) on the unaffected side of rats in the EA group, once a day for consecutive 5 d. The learning and memory abilities of rats were evaluated by water maze test 31-35 days after operation. The apoptosis of hippocampal neurons was observed by Tunel/NeuN double staining. The expressions of high mobility group protein B1 (HMGB1) and phosphorylated (p)-nuclear factor (NF)-κB in microglia cells in hippocampal dentate gyrus were detected by immunofluorescence staining. The expression levels of interleukin (IL)-6 and IL-1ß in the hippocampus were detected by Western blot. RESULTS: Compared with the sham operation group, the escape latency was prolonged (P<0.05); the frequency of crossing the original platform, ratio of the swimming distance and the time in the target quadrant of the Morris water maze were significantly decreased (P<0.05); the apoptosis rate of hippocampal neurons was significantly increased (P<0.05); the expressions of HMGB1 and p-NF-κB in microglia cells in the dentate gyrus and the expression levels of IL-6 and IL-1ß in hippocampus were increased (P<0.05) in the model group. Compared with the model group, the results of the above indexes were all opposite (P<0.05) in the EA group. CONCLUSION: EA preconditioning can regulate hippocampal inflammatory response, alleviate neuronal apoptosis rate and long-term cognitive dysfunction in aged rats with POCD, the mechanisms may be related to the inhibition of microglia HMGB1/NF-κB pathway in hippocampal dentate gyrus.
Assuntos
Eletroacupuntura , Doenças Neuroinflamatórias , Complicações Cognitivas Pós-Operatórias , Animais , Ratos , Complicações Cognitivas Pós-Operatórias/prevenção & controle , Complicações Cognitivas Pós-Operatórias/terapia , Doenças Neuroinflamatórias/prevenção & controle , Doenças Neuroinflamatórias/terapia , Proteína HMGB1/genética , Regulação da Expressão Gênica , NF-kappa B/genética , Interleucina-6/genética , Interleucina-1beta/genéticaRESUMO
Background: Femoral nerve block combined with general anesthesia is commonly used for patients undergoing knee arthroscopy in ambulatory care centers. An ideal analgesic agent would selectively (differentially) block sensory fibers, with little or no effect on motor nerves. Ropivacaine is considered to cause less motor block than others. This study investigated the median effective concentration (EC50) of ropivacaine for differential femoral nerve block in adults either younger or older than 60 years. Methods: Patients with American Society of Anesthesiologists physical status I-III and scheduled for knee arthroscopy were categorized as 18- to 60-years-old (Group 1), or older than 60 years (Group 2). Surgeries were performed under general anesthesia combined with femoral nerve block via 22 mL ropivacaine. The EC50 of ropivacaine for differential femoral nerve block was determined using the up-and-down method and probit regression. The primary outcome was the EC50 (95% confidence interval [CI]) of the 2 groups. Data on the sensory block, analgesic effect, complications, and hemodynamics during surgery were also recorded. Results: The EC50 of 22 mL ropivacaine for differential femoral nerve block of Group 1 (0.124%, 95% CI 0.097-0.143%) was significantly higher than that of Group 2 (0.088%, 95% CI 0.076-0.103%). The sensory block and hemodynamic data of the 2 groups were comparable. None of the patients experienced neurological complications. Conclusion: The EC50 of ropivacaine administered for differential femoral nerve block during knee arthroscopy was lower in patients older than 60 years, relative to younger adults.
RESUMO
Sevoï¬urane, a commonly used anesthetic agent has been confirmed to induce cognitive impairment in aged rats. Normobaric hyperoxia preconditioning has been demonstrated to induce neuroprotection in rats. The present study aimed to determine whether normobaric hyperoxia preconditioning could ameliorate cognitive deficit induced by sevoflurane and the possible mechanism by which it may exert its effect. A total of 66, 20-month-old male Sprague-Dawley rats were randomly divided into 3 groups (n=22 each): Rats in the control (C) and sevoflurane anesthesia (S) groups received no normobaric hyperoxia preconditioning before sevoflurane exposure, rats in the normobaric hyperoxia pretreatment (HO) group received normobaric hyperoxia preconditioning before sevoflurane exposure (95% oxygen for 4 continuous h daily for 6 consecutive days). The anesthesia rats (S and HO groups), were exposed to 2.5% sevoflurane for 5 h, while the sham anesthesia rats (C group) were exposed to no sevoflurane. The neurobehavioral assessment was performed using a Morris water maze test, the expressions of the apoptosis proteins were determined using western blot analysis, and the apoptosis rate and cytosolic calcium concentration were measured by flow cytometry. Normobaric hyperoxia preconditioning improved prolonged escape latency and raised the number of platform crossings induced by sevoflurane in the Morris water maze test, increased the level of bcl-2 protein, and decreased the level of bax and active caspase-3 protein, the apoptosis rate and cytosolic calcium concentration in the hippocampus 24 h after sevoflurane exposure. The findings of the present study may imply that normobaric hyperoxia preconditioning attenuates sevoflurane-induced spatial learning and memory impairment, and this effect may be partly related to apoptosis inhibition in the hippocampus. In conclusion, normobaric hyperoxia preconditioning may be a promising strategy against sevoflurane-induced cognitive impairment by inhibiting the hippocampal neuron apoptosis.
RESUMO
Trimethylamine-N-oxide (TMAO) is a gut microbial metabolite that promotes Alzheimer's disease (AD) progression. Given that probiotics can alleviate AD symptoms by inhibiting the synthesis of TMAO, here we investigated the correlation between TMAO and cognitive deterioration by measuring TMAO levels in the plasma of choline-treated APP/PS1 mice (an AD mouse model) with and without probiotic treatments. We found that declines in L.plantarum in the gut were associated with cognitive impairment. Moreover, 12-weeks of treatment with memantine plus L. plantarum ameliorated cognitive deterioration, decreased Αß levels in the hippocampus, and protected neuronal integrity and plasticity. These effects were accompanied by reductions in TMAO synthesis and neuroinflammation. These experiments demonstrate that L. plantarum augments the beneficial therapeutic effects of memantine treatment in APP/PS1 mice by remodeling the intestinal microbiota, inhibiting the synthesis of TMAO, and reducing clusterin levels. Our results thus highlight intestinal microbiota as a potential therapeutic target to decrease the risk of AD.
Assuntos
Doença de Alzheimer/complicações , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/terapia , Lactobacillus plantarum , Memantina/farmacologia , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Animais , Animais Geneticamente Modificados , Biomarcadores , Colina/administração & dosagem , Suplementos Nutricionais , Modelos Animais de Doenças , Microbioma Gastrointestinal , Masculino , Metagenômica/métodos , Camundongos , Probióticos , Células Piramidais/metabolismoRESUMO
BACKGROUND: Isoflurane, a commonly used inhaled anesthetic, induces apoptosis in primary rat cortical neurons of rat in a concentration- and time-dependent manner by an unknown mechanism. We hypothesized that isoflurane induced apoptosis by causing abnormal calcium release from the endoplasmic reticulum (ER) via activation of inositol 1, 4, 5-trisphosphate (IP(3)) receptors. Sevoflurane has a reduced ability to disrupt intracellular calcium homeostasis and is a less potent cytotoxic agent. This study examined and compared the cytotoxic effects of isoflurane and sevoflurane on rat primary cortical neurons and their relationship with disruption of intracellular calcium homeostasis and production of reactive oxygen species (ROS). METHODS: Primary rat cortical neurons were treated with the equivalent of 1 minimal alveolar concentration (MAC) of isoflurane and sevoflurane for 12 hours. MTT reduction and LDH release assays were performed to evaluate cell viability. Changes of calcium concentration in the cytosolic space, [Ca(2+)](c), and production of ROS were determined after exposing primary rat cortical neurons to isoflurane and sevoflurane. We also determined the effects of IP(3) receptor antagonist xestospongin C on isoflurane-induced cytotoxicity and calcium release from the ER in primary rat cortical neurons. RESULTS: Isoflurane at 1 MAC for 12 hours induced cytotoxicity in primary rat cortical neurons, which was also associated with a high and fast elevation of peak [Ca(2+)](c). Xestospongin C significantly ameliorated isoflurane cytotoxicity in primary cortical neurons, as well as inhibited the calcium release from the ER in primary cortical neurons. Isoflurane did not induce significant changes of ROS production in primary rat cortical neurons. Sevoflurane, at equivalent exposure to isoflurane, did not induce similar cytotoxicity or elevation of peak [Ca(2+)](c) in primary rat cortical neurons. CONCLUSION: These results suggested that isoflurane induced elevation in [Ca(2+)](c), partially via elevated activity of IP(3) receptors, which rendered cells vulnerable to isoflurane neurotoxicity. ROS production was not involved in isoflurane-induced neurotoxicity. Sevoflurane, at an equivalent exposure to isoflurane, did not induce similar elevations of [Ca(2+)](c) or neurotoxicity in primary cortical neurons of rat.
Assuntos
Anestésicos Inalatórios/toxicidade , Isoflurano/toxicidade , Éteres Metílicos/toxicidade , Animais , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Receptores de Inositol 1,4,5-Trifosfato/efeitos dos fármacos , Receptores de Inositol 1,4,5-Trifosfato/fisiologia , Ratos , Espécies Reativas de Oxigênio/metabolismo , SevofluranoRESUMO
Transcutaneous electrical acupoint stimulation (TEAS) is a emerging treatment which combines transcutaneous electrical nerve stimulation with traditional acupoint therapy. The present study was aimed to evaluate the effect of TEAS on the effective concentration (EC50) of remifentanil suppressing tracheal extubation response in elderly patients.Fifty-three patients undergoing spine surgery were randomly divided into 2 groups: control group (groupâC, nâ=â26) and transcutaneous electrical acupoint stimulation group (group TEAS, nâ=â27). The EC50 values for remifentanil TCI were determined using sequential method and probit analysis.The remifentanil EC50 of that suppressed responses to extubation during anesthetic emergence was 1.20âng/mL in group TEAS, a value that was significantly lower than the 1.64âng/mL needed by patients in group C.The TEAS can enhance the efficacy of remifentanil on suppressing responses to tracheal extubation in elderly patients, the EC50 of remifentanil can reduce approximately 27% compared with group C.
Assuntos
Analgesia por Acupuntura/métodos , Pontos de Acupuntura , Extubação/métodos , Analgésicos Opioides/administração & dosagem , Remifentanil/administração & dosagem , Estimulação Elétrica Nervosa Transcutânea/métodos , Idoso , Idoso de 80 Anos ou mais , Extubação/efeitos adversos , Período de Recuperação da Anestesia , Terapia Combinada , Feminino , Humanos , Masculino , Estudos Prospectivos , Resultado do TratamentoRESUMO
Electro-acupuncture is a burgeoning treatment using the needle inserting into the body acupoints and the low-frequency pulse current being electrified by an electric acupuncture machine. This study was designed to evaluate the effects of preconditioning of electro-acupuncture on postoperative cognitive dysfunction in elderly.Ninety patients scheduled spine surgery were randomly assigned into 2 groups using a random number table: control group (group C) and electro-acupuncture group (group EA). In group EA, electro-acupuncture was applied on Baihui, Dazhui, and Zusanli acupoints 30âminutes before anesthesia. At 0âminute before treatment of electro-acupuncture, 1âhour after skin incision and surgery completed (T1-3), blood samples were taken for detection of interleukin (IL)-6, IL-10, and S100ß by enzyme-linked immunosorbent assay. The total dose of remifentanil and propofol during surgery were recorded. Mini-Mental State Examination was applied to evaluate the cognitive function of patients at 1 day before surgery and 7th and 30th day after surgery.The results showed that compared with group C, score of MMSE increased after surgery, the serum concentration of IL-6, IL-10, and S100ß decreased at 1âhour after skin incision, and surgery completed in group EA. Moreover, the total dose of remifentanil and propofol reduced during surgery in group EA.The present study suggests that preconditioning of electro-acupuncture could improve the postoperative cognitive function, and the reduction of inflammatory reaction and brain injury may be involved in the mechanism.
Assuntos
Disfunção Cognitiva/etiologia , Disfunção Cognitiva/prevenção & controle , Eletroacupuntura , Complicações Pós-Operatórias/prevenção & controle , Cuidados Pré-Operatórios , Coluna Vertebral/cirurgia , Idoso , Anestésicos Intravenosos/uso terapêutico , Biomarcadores/sangue , Disfunção Cognitiva/sangue , Feminino , Humanos , Interleucina-10/sangue , Interleucina-6/sangue , Masculino , Entrevista Psiquiátrica Padronizada , Duração da Cirurgia , Procedimentos Ortopédicos , Piperidinas/uso terapêutico , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/psicologia , Propofol/uso terapêutico , Remifentanil , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Resultado do TratamentoRESUMO
Nimodipine is a clinical commonly used calcium antagonistscan lowering the apoptosis rate of hippocampal neuron to reduce the incidence of postoperative cognitive dysfunction (POCD). This study was designed to evaluate the effects of nimodipine on postoperative delirium in elderly under general anesthesia.Sixty patients shceduced spine surgery under general anesthesia were randomly assigned into 2 groups using a random number table: control group (GroupâC) and nimodipine group (GroupâN). In Group N, nimodipine 7.5âµg/(kg × h) was injected continually 30âminutes before anesthesia induction, while the equal volume of normal saline was given in Group C. At 0âminute before injection, 0âminute after tracheal intubation, 1âhour after skin incision and surgery completed (T1-4), blood samples were taken from the radial artery and jugular bulb for blood gas analysis. Cerebral oxygen metabolism-related indicators were calculated at the same time. Concentration of S100ß and glial fibrillary acidic protein (GFAP) were tested by ELISA. The incidence of postoperative delirium within 7 days after surgery was recorded.Cerebral oxygen metabolism-related indicators fluctuationed in the normal range in 2 groups at different time points and the difference were not statistically significant. Compared with Group C, S100ß and GFAP decreased and incidence of postoperative delirium reduced at T3-4 in Group N, the difference was statistically significant (P<.05).The present study suggests that nimodipine can reduce the development of postoperative delirium in elderly patients under general anesthesia, the reduction of brain injury and improvement of cerebral oxygen metabolism may be involved in the mechanism.
Assuntos
Anestesia Geral/efeitos adversos , Delírio/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Nimodipina/uso terapêutico , Procedimentos Ortopédicos/efeitos adversos , Complicações Pós-Operatórias/tratamento farmacológico , Idoso , Gasometria , Cérebro/metabolismo , Delírio/epidemiologia , Delírio/etiologia , Delírio/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Proteína Glial Fibrilar Ácida/sangue , Humanos , Incidência , Masculino , Oxigênio/metabolismo , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/metabolismo , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Coluna Vertebral/cirurgia , Resultado do TratamentoRESUMO
Paliurus favonii Unger is recognized and described based on fruits from the Oligocene Ningming flora of Guangxi, South China. Characteristics of the present specimens include circular winged fruits that are 10.0-11.5 mm in diameter with a central endocarp at 3.0 to 4.0 mm in diameter. The specimens fall into the morphological range of the fossil species P. favonii, which has been observed in other Cenozoic sites in the Northern Hemisphere. The present discovery represents the lowest latitude distribution of P. favonii in the world, and we are presenting the first P. favonii fossil described with detailed cuticular characteristics from China. Further, this finding demonstrates that the genus existed in the Oligocene Ningming region, South China, and provides new information for understanding the fossil history. The dispersal mode for winged fossils demonstrates that wind dispersal is well-represented in the Oligocene Ningming flora.
Assuntos
Fósseis/anatomia & histologia , Frutas/anatomia & histologia , Folhas de Planta/anatomia & histologia , Rhamnaceae/anatomia & histologia , Rhamnaceae/classificação , Evolução Biológica , China , Geografia , FilogeografiaRESUMO
Cyanotis arachnoidea contains a rich source of bioactive phytoecdysteroids (i.e. analogues of insect steroid hormones). 3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) supplies mevalonate for the synthesis of many secondary metabolites including 20-hydroxyecdysone (20E), one of metabolism-enhancing phytoecdysteroids. In this study, in order to develop a sustainable source of 20E, cell suspension cultures were established from shoot cultures of C. arachnoidea, and a full length cDNA encoding HMGR (designated as CaHMGR) was cloned and characterized. The cDNA contained 2037 nucleotides with a complete open reading frame (ORF) of 1800 nucleotides, which was predicted to encode a peptide of 599 amino acids. Expression analysis by real-time PCR revealed that CaHMGR mRNA was abundant in C. arachnoidea stems, roots and leaves. When cultivated in Murashige & Skoog medium supplemented with 0.2 mg L(-1) 1-naphthlcetic acid (NAA) and 3.0 mg L(-1) 6-benzyladenine (6-BA), C. arachnoidea cells in suspension culture grew rapidly, yielding 20E (124.14 µg L(-1)) after 12 days. The content of 20E in cell cultures elicited by 0.2 mM methyl jasmonate (MeJA), 100 mg L(-1) yeast elicitor (YE) or 25 µM AgNO3 was increased 8-, 2-, and 6-fold over the control, respectively. Quantitative real-time PCR analysis showed that CaHMGR was expressed at a higher level under the treatment of MeJA or Ag(+) elicitor. Our results suggested that 20E accumulation may be the result of the expression up-regulation of CaHMGR involved in the biosynthesis under the treatment of various elicitors.
Assuntos
Commelinaceae/genética , Acetatos/farmacologia , Acil Coenzima A/metabolismo , Ácidos Carboxílicos/farmacologia , Clonagem Molecular , Commelinaceae/química , Ciclopentanos/farmacologia , Ecdisterona/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Naftalenos/farmacologia , Fases de Leitura Aberta , Oxilipinas/farmacologia , Reação em Cadeia da Polimerase em Tempo RealAssuntos
Lipopolissacarídeos/toxicidade , Pulmão/patologia , Ventiladores Mecânicos/efeitos adversos , Animais , Líquido da Lavagem Broncoalveolar/química , Quimiocina CCL2/análise , Imuno-Histoquímica , Receptores de Lipopolissacarídeos/análise , Receptores de Lipopolissacarídeos/genética , Masculino , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley , Fator de Necrose Tumoral alfa/análiseRESUMO
Quantitative determination of the allele frequency of single-nucleotide polymorphism (SNP) in pooled DNA samples is a promising approach to clarify the relationships between SNPs and diseases. Here, we present such a simple, accurate, and inexpensive method for quantitative determining the allele frequency in pooled DNA samples. Three steps of DNA pooling, PCR amplification and sequencing are involved in this assay. Although direct determination of the allele frequency from the two allele-specific fluorescence intensities is possible, correction for differential response of alleles is important. We explored the effect of differential response of alleles on test statistics and provide a solution to this problem based on heterozygous fluorescence intensities. We demonstrate the accuracy and reliability of this assay on pooled DNA samples with pre-determined allele frequencies from 7.1% to 53.9%. The accuracy of allele frequency measurements is high, with a correlation coefficient of r² = 0.997 between measured and known frequencies. We believe that by providing a means for SNP genotyping up to hundreds of samples simultaneously, inexpensively, and reproducibly, this method is a powerful strategy for detecting meaningful polymorphic differences in candidate gene association studies.
Assuntos
DNA/química , Frequência do Gene/genética , Estudos de Associação Genética/métodos , Análise de Sequência de DNA/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Nucleotídeo Único , Reprodutibilidade dos Testes , Neoplasias Gástricas/genéticaRESUMO
Diabetic neuropathic pain is a common clinical problem and remains difficult to treat with classic analgesics. Spinal dorsal horn neurons are important in mediating nociceptive signaling, and the hyperactivity of these neurons is critical in diabetic neuropathy. In this study, we determined the GABA(B) receptor expression level in dorsal horn neurons in streptozotocin (STZ)-induced diabetes in rats by using reverse-transcription polymerase chain reaction (RT-PCR) and western blot analyses. Mean blood glucose concentrations were significantly higher and the paw withdrawal threshold was significantly lower in STZ-treated rats than in saline-treated rats. Immunohistochemical staining showed that the GABA(B) receptor was extensively expressed in the spinal dorsal horn neurons. The GABA(B1) mRNA level decreased in a time-dependent manner in STZ-treated rats compared with saline-treated controls. Furthermore, the protein expression level revealed by western blot analysis was lower in STZ-treated rats than in saline-treated rats. These data suggest that GABA(B) receptors are downregulated in the spinal dorsal horn in this model of STZ-induced diabetic neuropathic pain. The reduction of GABA(B) expression may contribute to the hyperactivity of spinal dorsal horn neurons and diabetic neuropathic pain.
Assuntos
Diabetes Mellitus Experimental/metabolismo , Neuropatias Diabéticas/metabolismo , Regulação para Baixo/fisiologia , Células do Corno Posterior/metabolismo , Receptores de GABA-B/metabolismo , Animais , Diabetes Mellitus Experimental/patologia , Neuropatias Diabéticas/patologia , Masculino , Medição da Dor/métodos , Células do Corno Posterior/patologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores de GABA-B/biossíntese , Medula Espinal/metabolismo , Medula Espinal/patologiaRESUMO
In 2006-2007, a field trial was conducted to study the effects of applying three kinds of organic-inorganic compound fertilizers [rapeseed cake compost plus inorganic fertilizers (RCC), pig manure compost plus inorganic fertilizers (PMC), and Chinese medicine residues plus inorganic fertilizers (CMC)] on the crop growth and nitrogen (N) use efficiency of rice-wheat rotation system in South Jiangsu. Grain yield of wheat and rice in the different fertilization treatments was significantly higher than the control (no fertilization). In treatments RCC, PMC and CMC, the wheat yield was 13.1%, 32.2% and 39.3% lower than that of the NPK compound fertilizer (CF, 6760 kg x hm(-2)), respectively, but the rice yield (8504-9449 kg x hm(-2)) was significantly higher than that (7919 kg x hm(-2)) of CF, with an increment of 7.4%-19.3%. In wheat season, the aboveground dry mass, N accumulation, and N use efficiency in treatments RCC, PMC, and CMC were lower than those of CF, but in rice season, these parameters were significantly higher than or as the same as CF. In sum, all the test three compound fertilizers had positive effects on the rice yield and its nitrogen use efficiency in the rice-wheat rotation system, being most significant for RCC.
Assuntos
Agricultura/métodos , Fertilizantes/classificação , Esterco , Oryza/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , China , Compostos Inorgânicos/química , Nitrogênio/metabolismo , Compostos Orgânicos/químicaRESUMO
A field experiment was carried to study the effects of organic-inorganic mixed fertilizers on rice yield, nitrogen (N) use efficiency, soil N supply, and soil microbial diversity. Rapeseed cake compost (RCC), pig manure compost (PMC), and Chinese medicine residue compost (MRC) were mixed with chemical N, P and K fertilizers. All the treatments except CK received the same rate of N. The results showed that all N fertilizer application treatments had higher rice yield (7918.8-9449.2 kg x hm(-2)) than the control (6947.9 kg x hm(-2)). Compared with that of chemical fertilizers (CF) treatment (7918.8 kg x hm(-2)), the yield of the three organic-inorganic mixed fertilizers treatments ranged in 8532.0-9449.2 kg x hm(-2), and the increment was 7.7%-19.3%. Compared with treatment CF, the treatments of organic-inorganic mixed fertilizers were significantly higher in N accumulation, N transportation efficiency, N recovery rate, agronomic N use efficiency, and physiological N use efficiency. These mixed fertilizers treatments promoted rice N uptake and improved soil N supply, and thus, increased N use efficiency, compared with treatments CF and CK. Neighbor joining analysis indicated that soil bacterial communities in the five treatments could be classified into three categories, i.e., CF and CK, PMC and MRC, and RCC, implying that the application of exogenous organic materials could affect soil bacterial communities, while applying chemical fertilizers had little effect on them.