The Experts below are selected from a list of 6420 Experts worldwide ranked by ideXlab platform
Qirong Shen - One of the best experts on this subject based on the ideXlab platform.
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continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2018Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:Bio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear. A 3-season field experiment containing four fertilization management programs (chemical fertilizer, organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer was conducted in a tomato production agroecosystem with high disease incidence to evaluate the induced efficacy. The bacterial and fungal Microflora of bulk and rhizosphere Soil influenced by different management programs were performed on the Illumina MiSeq platform. Principal coordinate analysis based on the Bray-Curtis distance metric was performed to compare the similarities and differences of the bacterial and fungal community compositions among all Soil samples. Soil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons. Interestingly, rhizospheric and bulk Soil bacterial and fungal communities of the different fertilization management programs were separated from each other. Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk Soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere Soils of bio-organic fertilizer treatments. Additionally, the redundancy analysis results showed the genera in treated chemical fertilizer bulk Soil were dominated by Ralstonia and Fusarium, the abundances of which were highest and lowest in treated chemical fertilizer and bio-organic fertilizer rhizosphere, respectively. This study provided insights into Soil-borne disease suppression by bulk Soil management and confirmed that alterations to the bulk Soil microbiota by different organic additives played distinct roles in the formation of rhizospheric Soil Microflora for the suppression of disease.
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Continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2017Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:AimsBio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear.MethodsA 3-season field experiment containing four fertilization management programs (chemical fertilizer, organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer was conducted in a tomato production agroecosystem with high disease incidence to evaluate the induced efficacy. The bacterial and fungal Microflora of bulk and rhizosphere Soil influenced by different management programs were performed on the Illumina MiSeq platform. Principal coordinate analysis based on the Bray-Curtis distance metric was performed to compare the similarities and differences of the bacterial and fungal community compositions among all Soil samples.ResultsSoil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons. Interestingly, rhizospheric and bulk Soil bacterial and fungal communities of the different fertilization management programs were separated from each other. Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk Soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere Soils of bio-organic fertilizer treatments. Additionally, the redundancy analysis results showed the genera in treated chemical fertilizer bulk Soil were dominated by Ralstonia and Fusarium, the abundances of which were highest and lowest in treated chemical fertilizer and bio-organic fertilizer rhizosphere, respectively.ConclusionsThis study provided insights into Soil-borne disease suppression by bulk Soil management and confirmed that alterations to the bulk Soil microbiota by different organic additives played distinct roles in the formation of rhizospheric Soil Microflora for the suppression of disease.
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Continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2017Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:Aims Bio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear.
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Novel Soil fumigation method for suppressing cucumber Fusarium wilt disease associated with Soil Microflora alterations
Applied Soil Ecology, 2016Co-Authors: Zongzhuan Shen, Ruifu Zhang, Li Sun, Xuhui Deng, Qirong ShenAbstract:Fusarium wilt in cucumber results from continuous cropping and is a serious Soil-borne fungal disease that threatens cucumber production around the world. The application of a novel fumigation agent based on ammonium bicarbonate to the Soil as a strategy for controlling Fusarium wilt and its effects on Soil Microflora was investigated in a field with serious disease incidence in this study. Overall, the results showed that fumigation effectively controlled cucumber Fusarium wilt disease and significantly increased the total and mean cucumber fruit weight. Real-Time PCR results showed that the total bacterial and fungal numbers in the treatment (LAB) significantly decreased after fumigation and that significantly fewer fungi were observed after harvest (LABOF). The next-generation sequencing of the 16S rRNA and internal transcribed spacer (ITS) genes using MiSeq platform showed that the Soil bacterial and fungal community structures in the fumigation treatment were significantly different from the control without fumigation regardless after fumigation or harvest. Compared to the control, higher abundances of Gemmatimonadetes, Verrucomicrobia and Zygomycota, and lower abundance of Ascomycota were observed in the fumigated Soils after fumigation and harvest. Furthermore, the abundances of Mortierella and Gp1 were significantly higher. Most importantly, the abundance of Fusarium, which includes the pathogen potentially responsible for cucumber Fusarium wilt disease, was significantly lower in the fumigated Soils after harvest. Redundancy analysis showed that the fumigated Soils were dominated by Ohtaekwangia, Gp6, and Gp4, which were related to the Soil total nitrogen (TN), ammonium nitrogen (NH4–N) and nitrate nitrogen (NO3–N) contents. In addition, Penicillium and Pseudaleuria fungi were dominant in the treatment and control, and the control was dominated by Fusarium. In conclusion, the observed disease suppression due to the novel ecological Soil fumigation strategy may be attributed to general suppression resulting from altered Soil properties, such as higher Soil NH4–N, NO3–N and TON contents, and the alteration of the disturbed Soil Microflora in a cucumber monoculture system.
Richard J. Haynes - One of the best experts on this subject based on the ideXlab platform.
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Organic matter status and the size, activity and metabolic diversity of the Soil Microflora as indicators of the success of rehabilitation of mined sand dunes
Biology and Fertility of Soils, 2004Co-Authors: M. H. Graham, Richard J. HaynesAbstract:The effectiveness of the rehabilitation of mined sand dunes on the northern coast of KwaZulu–Natal, South Africa, was assessed based on measurements of the total and labile organic matter content and the size, activity and metabolic diversity of the Soil Microflora. Soil was sampled (0–10 cm) after 0, 5, 10, 20 and 25 years of rehabilitation and compared with Soil under undisturbed native forest and under long-term commercial pine forest. Following topSoil removal, stockpiling and respreading on reformed dunes, there was a massive loss of organic C such that, at time zero, organic C content was only 24% of that present under native forest. Soil organic C content increased progressively during rehabilitation until, after 25 years, it represented 93% of that present under native forest. The pattern of change in light-fraction C, KMnO4-extractable C, water-soluble C, microbial biomass C, basal respiration and arginine ammonification rate was broadly similar to that for organic C, but the extent of the initial loss and the magnitude of the subsequent increase differed. Microbial biomass C, water-soluble C and KMnO4-extractable C, expressed as a percentage of organic C, declined during rehabilitation as humic substances progressively accumulated. Principal component (PC) analysis of catabolic response profiles to 36 substrates revealed that the catabolic diversity of microbial communities differed greatly between native forest, commercial pine forest, 0 years and 10 years of rehabilitation. On the PC1 axis, values for Soils under native forest and after 25 years rehabilitation were similar, but there was still separation on the PC2 axis. The main factor explaining variation in response profiles on the PC1 axis was organic C content; and the greatest catabolic diversity occurred in Soils under native forest and after 25 years of rehabilitation.
Ruifu Zhang - One of the best experts on this subject based on the ideXlab platform.
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continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2018Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:Bio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear. A 3-season field experiment containing four fertilization management programs (chemical fertilizer, organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer was conducted in a tomato production agroecosystem with high disease incidence to evaluate the induced efficacy. The bacterial and fungal Microflora of bulk and rhizosphere Soil influenced by different management programs were performed on the Illumina MiSeq platform. Principal coordinate analysis based on the Bray-Curtis distance metric was performed to compare the similarities and differences of the bacterial and fungal community compositions among all Soil samples. Soil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons. Interestingly, rhizospheric and bulk Soil bacterial and fungal communities of the different fertilization management programs were separated from each other. Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk Soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere Soils of bio-organic fertilizer treatments. Additionally, the redundancy analysis results showed the genera in treated chemical fertilizer bulk Soil were dominated by Ralstonia and Fusarium, the abundances of which were highest and lowest in treated chemical fertilizer and bio-organic fertilizer rhizosphere, respectively. This study provided insights into Soil-borne disease suppression by bulk Soil management and confirmed that alterations to the bulk Soil microbiota by different organic additives played distinct roles in the formation of rhizospheric Soil Microflora for the suppression of disease.
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Continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2017Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:AimsBio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear.MethodsA 3-season field experiment containing four fertilization management programs (chemical fertilizer, organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer was conducted in a tomato production agroecosystem with high disease incidence to evaluate the induced efficacy. The bacterial and fungal Microflora of bulk and rhizosphere Soil influenced by different management programs were performed on the Illumina MiSeq platform. Principal coordinate analysis based on the Bray-Curtis distance metric was performed to compare the similarities and differences of the bacterial and fungal community compositions among all Soil samples.ResultsSoil amended with organic fertilizer, amino acid organic fertilizer, and bio-organic fertilizer progressively and significantly suppressed tomato diseases in comparison with chemical fertilizer, and bio-organic fertilizer presented the best efficacy in all seasons. Interestingly, rhizospheric and bulk Soil bacterial and fungal communities of the different fertilization management programs were separated from each other. Six bacterial and 10 fungal rhizospheric genera positively correlated with the same genera observed in bulk Soil showing significant relationships with tomato disease incidence were observed, and functional strain SQR9 can be detected in the bulk and rhizosphere Soils of bio-organic fertilizer treatments. Additionally, the redundancy analysis results showed the genera in treated chemical fertilizer bulk Soil were dominated by Ralstonia and Fusarium, the abundances of which were highest and lowest in treated chemical fertilizer and bio-organic fertilizer rhizosphere, respectively.ConclusionsThis study provided insights into Soil-borne disease suppression by bulk Soil management and confirmed that alterations to the bulk Soil microbiota by different organic additives played distinct roles in the formation of rhizospheric Soil Microflora for the suppression of disease.
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Continuous application of different organic additives can suppress tomato disease by inducing the healthy rhizospheric microbiota through alterations to the bulk Soil Microflora
Plant and Soil, 2017Co-Authors: Hongjun Liu, Xinnan Hang, Wu Xiong, Ruifu Zhang, Dongsheng Wang, Qirong ShenAbstract:Aims Bio-organic fertilizer and different additives are widely applied to suppress Soil-borne diseases. However, how different additives alter bulk Soil Microflora and thereby induce the healthy rhizospheric Microflora remains unclear.
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Novel Soil fumigation method for suppressing cucumber Fusarium wilt disease associated with Soil Microflora alterations
Applied Soil Ecology, 2016Co-Authors: Zongzhuan Shen, Ruifu Zhang, Li Sun, Xuhui Deng, Qirong ShenAbstract:Fusarium wilt in cucumber results from continuous cropping and is a serious Soil-borne fungal disease that threatens cucumber production around the world. The application of a novel fumigation agent based on ammonium bicarbonate to the Soil as a strategy for controlling Fusarium wilt and its effects on Soil Microflora was investigated in a field with serious disease incidence in this study. Overall, the results showed that fumigation effectively controlled cucumber Fusarium wilt disease and significantly increased the total and mean cucumber fruit weight. Real-Time PCR results showed that the total bacterial and fungal numbers in the treatment (LAB) significantly decreased after fumigation and that significantly fewer fungi were observed after harvest (LABOF). The next-generation sequencing of the 16S rRNA and internal transcribed spacer (ITS) genes using MiSeq platform showed that the Soil bacterial and fungal community structures in the fumigation treatment were significantly different from the control without fumigation regardless after fumigation or harvest. Compared to the control, higher abundances of Gemmatimonadetes, Verrucomicrobia and Zygomycota, and lower abundance of Ascomycota were observed in the fumigated Soils after fumigation and harvest. Furthermore, the abundances of Mortierella and Gp1 were significantly higher. Most importantly, the abundance of Fusarium, which includes the pathogen potentially responsible for cucumber Fusarium wilt disease, was significantly lower in the fumigated Soils after harvest. Redundancy analysis showed that the fumigated Soils were dominated by Ohtaekwangia, Gp6, and Gp4, which were related to the Soil total nitrogen (TN), ammonium nitrogen (NH4–N) and nitrate nitrogen (NO3–N) contents. In addition, Penicillium and Pseudaleuria fungi were dominant in the treatment and control, and the control was dominated by Fusarium. In conclusion, the observed disease suppression due to the novel ecological Soil fumigation strategy may be attributed to general suppression resulting from altered Soil properties, such as higher Soil NH4–N, NO3–N and TON contents, and the alteration of the disturbed Soil Microflora in a cucumber monoculture system.
Aino Smolander - One of the best experts on this subject based on the ideXlab platform.
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Effect of nitrogen deposition level on nitrogen uptake and bud burst in Norway spruce (Picea abies Karst.) seedlings and N uptake by Soil Microflora
Forest Ecology and Management, 1996Co-Authors: Ilari Lumme, Aino SmolanderAbstract:Abstract The effect of nitrogen wet deposition on the N uptake of 3-year-old cloned Norway spruce (Picea abies Karst.) seedlings via roots and directly from wet deposition by needles and its subsequent allocation were investigated in a greenhouse experiment by applying solutions of 15N-labelled ammonium and nitrate. In addition, the immobilization of the added N by Soil Microflora and the effect of seedling rhizosphere on Soil microbial biomass was studied. The nitrogen applications corresponded approximately to 10, 50, 100 and 150 kg N ha−1 year−1 wet deposition. In another experiment, the effect of nitrogen deposition on the onset of bud burst in 3-year-old cloned Norway spruce seedlings was studied in the greenhouse and growth chambers. The N dosages corresponded approximately to 50, 150, 300, 600 and 1200 kg N ha−1 year−1 wet deposition. Nitrogen uptake both by roots and through needles correlated positively with the nitrogen application. Ammonium and nitrate applied separately were assimilated in similar amounts by the roots with native mycorrhizas. Ammonium-N was taken up through needles more readily than nitrate-N. The proportion of direct foliar N uptake was low compared with the N uptake by roots. The Soil microbial biomass increased in the presence of Norway spruce rhizosphere, but the amount of Microflora remained low due to low native Soil organic carbon content. Consequently allocation of the added nitrogen to microbial biomass was low. The microbial biomass C and N responded notably only to the highest application (150 kg N ha−1 year−1). Nitrogen deposition exceeding 100–150 kg N ha−1 year−1 advanced the onset of bud burst in the seedlings.
Guy Soulas - One of the best experts on this subject based on the ideXlab platform.
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A simplified procedure for terminal restriction fragment length polymorphism analysis of the Soil bacterial community to study the effects of pesticides on the Soil Microflora using 4,6-dinitroorthocresol as a test case
Biology and Fertility of Soils, 2003Co-Authors: Sandrine Rousseaux, Alain Hartmann, Nadine Rouard, Guy SoulasAbstract:We have studied the structural effects of application to the Soil of a potentially detrimental herbicide, 4,6-dinitroorthocresol (DNOC) by analysing amplified ribosomal DNA restriction analysis (ARDRA) and terminal restriction fragment length polymorphism (T-RFLP) signatures of 16S rDNA fragments of culturable bacterial communities isolated from diluted Soil suspensions. This approach has the potential to reveal changes induced by stressing the Soil Microflora with DNOC. This paper shows that, whereas only few changes of the ARDRA and T-RFLP profiles result from ageing of the Soil, treatment of the Soil with DNOC induces major modifications of these profiles. Therefore, for the practical purpose of pesticide registration, ARDRA and T-RFLP analysis performed on the dominant culturable fraction of the Soil bacteria, implemented using conventional gel electrophoresis, offers the means of a routine, simple and meaningful test for detecting some of the changes affecting the structure of the Soil Microflora in response to pesticide application.
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Side-effects of herbicides on the size and activity of the Soil Microflora: DNOC as a test case
European Journal of Soil Science, 1996Co-Authors: N. Rouard, M.-c. Dictor, Rémi Chaussod, Guy SoulasAbstract:Summary Recent advances in measuring Soil microbial biomass by chloroform fumigation–extraction (CFE) and microbial heterotrophic activity interpreted by quantitative concentration–activity relations (QCAR) have renewed interest in assessing side–effects of agricultural chemicals on Soil microorganisms. We have studied the effects of a herbicide, 4,6-dinitroorthocresol (DNOC), taken as a test chemical, on the rate of microbial carbon turnover and the size of the Soil microbial biomass. We used the CFE technique in combination with in-situ labelling of the Soil biomass. Exposure of prelabelled Soil samples to the herbicide resulted in a significant increase in 14CO2 production during which the radioactive carbon content of the Microflora decreased exponentially without apparent reduction in the size of the biomass. The extra production of 14CO2 by DNOC-treated Soil over control, or carbon-enriched Soil, is the expression of an increased rate of endogenous metabolism to compensate for shortage in energy caused by a decoupling of ATP generation at the oxidative phosphorylations level by the DNOC. To assess the influence of DNOC on Soil microbial communities we also compared the advantages of short-term respirometric tests with those resulting from application of heterotrophic activity measurements in connection with QCAR. Both procedures detected modifications in the metabolic behaviour of Soil microorganisms when faced with chemical stress. Short-term respirometric tests showed that DNOC causes a decrease in the respirometric activity of the Soil Microflora. Measuring heterotrophic activity also makes it possible to interpret microbial responses in terms of changes in the physiological traits of the microbial communities. DNOC provokes an apparent enrichment in microorganisms with a smaller saturation constant, Km and, as a consequence, a greater affinity for carbon substrates.
