Through collecting rhizosphere soil sample from a 30-year long-term fixed location test site that use“rice-ricerape”crop rotation(RRR)and“rice-rice-fallow”continuous cropping systems(RRF),this paper investigated e...Through collecting rhizosphere soil sample from a 30-year long-term fixed location test site that use“rice-ricerape”crop rotation(RRR)and“rice-rice-fallow”continuous cropping systems(RRF),this paper investigated effects of long-term crop rotation on physicochemical property and bacterial community of rhizosphere soil.Results showed that total nitrogen(TN),total phosphorus(TP)and available potassium(AK)contents in rhizosphere soil under long-term RRR were decreased by 28.09%,15.69%and 6.25%respectively.Alkali-hydrolyzable nitrogen(AN)and available phosphorus(AP)contents were 10.59%and 13.25%higher than those of soil in RRF respectively.Three soil samples collected during different periods also showed that RRR resulted in a lower rhizosphere soil pH than RRF.Clone library analysis revealed that significant difference in rhizosphere soil bacterial community was observed between RRR and RRF continuous cropping.Abundance ofα-Proteobacteria,β-Proteobacteria andγ-Proteobacteria were higher in rhizosphere soil of RRR compared to RRF.pH of rhizosphere soil was significantly correlated with Acidobacteria level,while total organic carbon(TOC)content was significantly correlated with Proteobacteria level.Long-term RRR enhanced conversion of N and P in rhizosphere soil,increased bio-availability to crop,and promoted diversity of soil bacterial community.Bacterial diversity in RRR could be ecological significance in maintaining soil fertility and functionality.展开更多
Soil siderophores are important for crop growth,benefit ferric iron absorption of root,and are affected by cropping patterns.The objective of this study was to evaluate the quantity of siderophores in soil of 2 contin...Soil siderophores are important for crop growth,benefit ferric iron absorption of root,and are affected by cropping patterns.The objective of this study was to evaluate the quantity of siderophores in soil of 2 continuous crop rotation patterns over 30 years in Anren country,China.Quantity and siderophore-producing capability of microorganisms in rice-riceoilseed rape(DDY)rotation and rice-rice(DD)rontinuous cropping rhizosphere soil were tested and analyzed by chrome azurol S method.Isolated strains were used to identify siderophore-producing microorganism(SPM)by PCR amplification and DNA sequencing.Results showed that 9 siderophore-producing bacteria strains were isolated from DDY rhizosphere soil while 7 strains were identified from DD rhizosphere soil.The mean solubility index which representing siderophore-producing capability of strains was 3.05.PCR amplification results indicated that bacterial were the major SPM in soil.This research indicates that crop rotation systems could drive microorganisms to produce siderophores and enrich them in bacterial communities.展开更多
With an annual incidence of 0.5 to 1.5/1000,cardiac arrest(CA)has emerged as a major global public health concern.[1]Although the American Heart Association(AHA)-International Liaison Committee on Resuscitation update...With an annual incidence of 0.5 to 1.5/1000,cardiac arrest(CA)has emerged as a major global public health concern.[1]Although the American Heart Association(AHA)-International Liaison Committee on Resuscitation updates the cardiopulmonary resuscitation(CPR)guidelines every 5 years,the survival rate and percentage of patients with good neurologic outcomes post-CA after hospital discharge have been relatively low.Therefore,the AHA 2010 CPR guidelines mention the treatment of post-cardiac arrest syndrome(PCAS)in the intensive care unit(ICU)as the fifth link in the CA survival chain.PCAS is a pathophysiological process that includes(1)brain injury,(2)myocardial dysfunction leading to hemodynamic instability,and(3)systemic ischemia/reperfusion response leading to lactate accumulation.[2]These key factors affect the survival and neurological prognosis of CA patients in the early stages.We assessed the effects of early hemodynamics,oxygen metabolism,and lactate dynamics during PCAS on a 28-day survival rate and neurological outcomes.展开更多
基金supported by the National Natural Science Foundation of China(No.31572203).
文摘Through collecting rhizosphere soil sample from a 30-year long-term fixed location test site that use“rice-ricerape”crop rotation(RRR)and“rice-rice-fallow”continuous cropping systems(RRF),this paper investigated effects of long-term crop rotation on physicochemical property and bacterial community of rhizosphere soil.Results showed that total nitrogen(TN),total phosphorus(TP)and available potassium(AK)contents in rhizosphere soil under long-term RRR were decreased by 28.09%,15.69%and 6.25%respectively.Alkali-hydrolyzable nitrogen(AN)and available phosphorus(AP)contents were 10.59%and 13.25%higher than those of soil in RRF respectively.Three soil samples collected during different periods also showed that RRR resulted in a lower rhizosphere soil pH than RRF.Clone library analysis revealed that significant difference in rhizosphere soil bacterial community was observed between RRR and RRF continuous cropping.Abundance ofα-Proteobacteria,β-Proteobacteria andγ-Proteobacteria were higher in rhizosphere soil of RRR compared to RRF.pH of rhizosphere soil was significantly correlated with Acidobacteria level,while total organic carbon(TOC)content was significantly correlated with Proteobacteria level.Long-term RRR enhanced conversion of N and P in rhizosphere soil,increased bio-availability to crop,and promoted diversity of soil bacterial community.Bacterial diversity in RRR could be ecological significance in maintaining soil fertility and functionality.
基金supported by the Natural Science Foundation of China (No. 31272248)the project of graduate innovation in Hunan Province (No. CX2017B364)
文摘Soil siderophores are important for crop growth,benefit ferric iron absorption of root,and are affected by cropping patterns.The objective of this study was to evaluate the quantity of siderophores in soil of 2 continuous crop rotation patterns over 30 years in Anren country,China.Quantity and siderophore-producing capability of microorganisms in rice-riceoilseed rape(DDY)rotation and rice-rice(DD)rontinuous cropping rhizosphere soil were tested and analyzed by chrome azurol S method.Isolated strains were used to identify siderophore-producing microorganism(SPM)by PCR amplification and DNA sequencing.Results showed that 9 siderophore-producing bacteria strains were isolated from DDY rhizosphere soil while 7 strains were identified from DD rhizosphere soil.The mean solubility index which representing siderophore-producing capability of strains was 3.05.PCR amplification results indicated that bacterial were the major SPM in soil.This research indicates that crop rotation systems could drive microorganisms to produce siderophores and enrich them in bacterial communities.
文摘With an annual incidence of 0.5 to 1.5/1000,cardiac arrest(CA)has emerged as a major global public health concern.[1]Although the American Heart Association(AHA)-International Liaison Committee on Resuscitation updates the cardiopulmonary resuscitation(CPR)guidelines every 5 years,the survival rate and percentage of patients with good neurologic outcomes post-CA after hospital discharge have been relatively low.Therefore,the AHA 2010 CPR guidelines mention the treatment of post-cardiac arrest syndrome(PCAS)in the intensive care unit(ICU)as the fifth link in the CA survival chain.PCAS is a pathophysiological process that includes(1)brain injury,(2)myocardial dysfunction leading to hemodynamic instability,and(3)systemic ischemia/reperfusion response leading to lactate accumulation.[2]These key factors affect the survival and neurological prognosis of CA patients in the early stages.We assessed the effects of early hemodynamics,oxygen metabolism,and lactate dynamics during PCAS on a 28-day survival rate and neurological outcomes.
