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Mark Mazzola - One of the best experts on this subject based on the ideXlab platform.
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comparative analysis of the rhizosphere and endophytic microbiomes across apple rootstock genotypes in replant Orchard Soils
Phytobiomes Journal, 2021Co-Authors: Christopher R Van Horn, Mark Mazzola, Tracey S SomeraAbstract:Apple replant disease (ARD), caused by a complex of soilborne pathogens, negatively impacts tree health and productivity in new Orchard plantings at sites previously planted to apple. Use of new di...
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the response of ammonia oxidizer activity and community structure to fertilizer amendment of Orchard Soils
Soil Biology & Biochemistry, 2014Co-Authors: Sarah L Strauss, Catherine L Reardon, Mark MazzolaAbstract:Abstract Soil microorganisms have a significant role in determining the relative loss and retention of plant available nitrogen (N) and thus relative efficiency in the use of fertility inputs to agricultural production systems. Although the effect of management system on activity of the N-cycling microbial communities has been evaluated in certain annual cropping systems, results have been variable and there have been few studies conducted in perennial crops, such as apple. We examined the effect of organic and mineral fertility inputs to organic and conventional Orchard Soils on the overall activity, abundance and diversity of ammonia-oxidizing bacteria and archaea. Apple rootstocks were cultivated in Orchard Soils receiving one of five fertility treatments: Brassica napus seed meal, plant-based compost, urea, urea with plant-based compost, and a no-treatment control. Based on analysis of the ammonia monooxygenase gene (amoA), ammonia-oxidizing archaea (AOA) were more abundant than ammonia-oxidizing bacteria (AOB) in both untreated conventionally and organically managed Orchard Soils. However, AOB abundance was significantly different in both organically and conventionally managed Soils with fertilizer amendments. The microbial community of the conventional Orchard soil appeared to be limited by inorganic N since a response in potential activity to N input was only observed in treatments with urea. In the organic Orchard soil, an increase in AOB gene abundance was detected only in response to the urea plus compost fertility treatment. Soil management and fertilizer additions had little effect on AOA gene abundance compared to the no-treatment control. Although composition of the AOB community was similar between the conventional and organically managed Soils, AOA communities were significantly different. The different responses of the bacterial and archaeal ammonia-oxidizer communities to organic and conventional management and fertilizer amendments highlight the need for an increased focus in agricultural research to understand and improve the specificity of fertilizer application for Orchard production systems.
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interaction of brassicaceous seed meal and apple rootstock on recovery of pythium spp and pratylenchus penetrans from roots grown in replant Soils
Plant Disease, 2009Co-Authors: Mark Mazzola, Jack Brown, Xiaowen Zhao, Antonio D Izzo, Gennaro FazioAbstract:ABSTRACT Pythium spp. and Pratylenchus penetrans are significant components of the diverse pathogen complex that incites apple replant disease in Washington State. The structure of the Pythium population differs among Orchard Soils but is composed of multiple pathogenic species. Studies were conducted to determine the effect of brassicaceous seed meals and apple rootstock on the activity and composition of these pathogen populations. Brassicaceous seed meals differed in capacity to suppress Pythium numbers and apple root infection, as well as differentially transformed composition of the population recovered from apple roots. Brassica juncea seed meal (SM) was the sole seed meal examined to suppress Pythium numbers and root infection; however, a persisting population was always detected in which Pythium irregulare existed as the dominant or co-dominant species. In general, the Geneva series rootstocks were less susceptible to root infection by native populations of Pythium, whereas M26, MM106, and MM111 w...
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role of native soil biology in brassicaceous seed meal induced weed suppression
Soil Biology & Biochemistry, 2008Co-Authors: Lori Hoagland, Lynne Carpenterboggs, Mark MazzolaAbstract:Abstract Biologically based weed control strategies are needed in organic and low-input systems. One promising practice is the application of Brassicaceous seed meal (BSM) residue, a byproduct of biodiesel production. When applied as a soil amendment, BSM residue has exhibited potential bioherbicide activity. In this study, tree fruit Orchard Soils were treated with various BSMs and the impact of Pythium on weed suppression was examined in field and greenhouse studies. Although weed control obtained in response to Brassicaceous residue amendments has been repeatedly attributed solely to release of allelopathic phytochemicals, multiple lines of evidence acquired in these studies indicate the involvement of a microbiological component. Reduced weed emergence and increased weed seedling mortality were not related to BSM glucosinolate content but were correlated with significant increases in resident populations of Pythium spp. in three different Orchard Soils. Seed meal of Brassica juncea did not amplify resident Pythium populations and did not suppress weed emergence. Application of Glycine max SM did stimulate Pythium spp. populations and likewise suppressed weed emergence. Application of a mefenoxam drench to Pythium -enriched soil significantly reduced weed suppression. These studies indicate that a microbial mechanism is involved in SM-induced weed suppression and that selective enhancement of resident pathogenic Pythium spp. can be utilized for the purpose of weed control.
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modification of fluorescent pseudomonad community and control of apple replant disease induced in a wheat cultivar specific manner
Applied Soil Ecology, 2003Co-Authors: Mark MazzolaAbstract:Apple Orchard Soils were cropped for three successive 28-day growth cycles with a perennial ryegrass/annual ryegrass mixture or 1 of 11 wheat cultivars prior to planting with Gala apple seedlings. Prior cropping of Soils with ryegrass had no significant impact on growth of apple, but cultivation with some, but not all, wheat cultivars substantially enhanced apple seedling growth. Enhanced growth of apple was associated with a reduction in root infection by the dominant fungal pathogens resident to the respective Orchard Soils. Wheat cultivars that enhanced growth of apple modified the genetic and species composition of the fluorescent pseudomonad population resident to Orchard soil. The fluorescent pseudomonad population from Soils cropped with wheat cultivars that enhanced apple seedling growth possessed a higher capacity to inhibit in vitro growth of multiple elements of the fungal complex that incites apple replant disease than did the population from non-treated Orchard soil or soil cropped with a wheat cultivar that did not enhance growth of apple. Application of wheat root exudates to soil also modified the antagonistic potential and composition of the fluorescent pseudomonad population in a cultivar-specific manner. This study demonstrates the significant role of plant genotype in determining composition of the saprophytic soil microbial community. It also establishes the need to consider not only plant species but also plant genotype when evaluating the potential benefit of specific cover crops as a component within a systems approach for the management of soilborne plant diseases.
Changyong Huang - One of the best experts on this subject based on the ideXlab platform.
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effect of lime application on microbial community in acidic tea Orchard Soils in comparison with those in wasteland and forest Soils
Journal of Environmental Sciences-china, 2010Co-Authors: Xiangdong Huang, Changyong HuangAbstract:Lime application is a conventional technology to control acidification in tea Orchard Soils. We investigated the effect of lime application on soil microbial community diversity in the Soils of three tea Orchards, wasteland and forest. The BIOLOG data showed that both the average well color development of all carbon sources and the functional diversity index increased with the liming rate in the tea Orchards and the forest, but decreased in the wasteland. The phospholipid fatty acid (PLFA) analysis showed that the structural diversity index of soil microbial community increased with the liming rate in all the tea Orchards, the wasteland and the forest. Lime application also increased the soil-bacterial PLFA content in all the Soils. Soil fungal and actinomycete PLFAs in the tea Orchards showed an increasing trend from 0 to 3.2 g CaCO3/kg application and then a decreasing trend from 3.2 to 6.4 g CaCO3/kg application. The principal component analysis of BIOLOG and PLFA data suggested that lime application had a significant effect on soil microbial community structure, and land use had a greater effect on soil microbial community structure compared to lime application.
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nitrification potentials of chinese tea Orchard Soils and their adjacent wasteland and forest Soils
Journal of Environmental Sciences-china, 2009Co-Authors: Yangmei Gao, Huaiying Yao, Dong Xue, Changyong HuangAbstract:To investigate the nitrifying activities of different soil types, soil samples collected from 8-, 50- and 90-year old tea Orchards, the adjacent wasteland, and 90-year old forest were measured for their nitrification potentials using the conventional soil incubation and the liquid incubation method. Among different soil types, the nitrification potential of soil in tea Orchards was higher than that of wasteland and forest Soils. The slurry shaken liquid incubation method was confirmed to be more accurate and have reliable results than the soil incubation. Interestingly, experimental result revealed that the generally applied pH value of 7.2 for the liquid media was not the optimal pH for these acid Soils with a strong buffer capacity. This suggested that tea Orchard Soils may have nitrifiers requiring pH-neutral condition for the best activity. Our data also showed that treatment with the commonly used nitrogen fertilizer urea significantly improved nitrification potential of the Soils; such enhancement effect was stronger on all of three tea Orchard Soils than on wasteland and forest Soils, and also stronger on the younger (8- and 50-year old) tea Orchard Soils than on the older one (90-year old).
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microbial biomass n mineralization and nitrification enzyme activities and microbial community diversity in tea Orchard Soils
Plant and Soil, 2006Co-Authors: Dong Xue, Huaiying Yao, Changyong HuangAbstract:Understanding the chronological changes in soil microbial and biochemical properties of tea Orchard ecosystems after wasteland has been reclaimed is important from ecological, environmental, and management perspectives. In this study, we determined microbial biomass, net N mineralization, and nitrification, enzyme (invertase, urease, proteinase, and acid phosphatase) activities, microbial community diversity assessed by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA polymerase chain reaction (PCR) products, and related ecological factors in three tea Orchard systems (8-, 50-, and 90-year-old tea Orchards), adjacent wasteland and 90-year-old forest. Soil microbial biomass C (Cmic) and activity, i.e., soil basal respiration (Rmic), microbial biomass C as a percent of soil organic C (Cmic/Corg), N mineralization, invertase, urease, proteinase, and acid phosphatase, significantly increased after wasteland was reclaimed; however, with the succeeding development of tea Orchard ecosystems, a decreasing trend from the 50- to 90-year-old tea Orchard became apparent. Soil net nitrification showed an increasing trend from the 8- to 50-year-old tea Orchard and then a decreasing trend from the 50- to 90-year-old tea Orchard, and was significantly higher in the tea Orchards compared to the wasteland and forest. Urea application significantly stimulated soil net nitrification, indicating nitrogen fertilizer application may be an important factor leading to high-nitrification rates in tea Orchard Soils. The Shannon’s diversity index (H) and richness (S) based on DGGE profiles of 16S rRNA genes were obviously lower in all three tea Orchards than those in the wasteland; nevertheless, they were significantly higher in all three tea Orchards than those in the forest. As for the three tea Orchard Soils, comparatively higher community diversity was found in the 50-year-old tea Orchard.
Ajesh K Singh - One of the best experts on this subject based on the ideXlab platform.
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links between ammonia oxidizer community structure abundance and nitrification potential in acidic Soils
Applied and Environmental Microbiology, 2011Co-Authors: Huaiying Yao, Graeme W Nicol, Yangmei Gao, Coli D Campbell, Limei Zhang, Ajesh K Singh, James I ProsseAbstract:Ammonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea Orchard Soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea Soils and adjacent pine forest Soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOB amoA gene abundance increased with decreasing soil pH in the tea Orchard Soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic Soils. Dominant AOA amoA sequences in the highly acidic tea Soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic Soils. Specific AOA and AOB populations dominated in Soils at particular pH values and N content, suggesting adaptation to specific niches.
Dong Xue - One of the best experts on this subject based on the ideXlab platform.
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microbial biomass community diversity and enzyme activities in response to urea application in tea Orchard Soils
Communications in Soil Science and Plant Analysis, 2010Co-Authors: Dong Xue, Huaiying YaoAbstract:To improve yield and quality in tea Orchards, a large amount of nitrogen (N) fertilizer is usually applied. Our objective was to evaluate the effect of N application on microbial community and activity in tea Orchard Soils and assess the relative importance of fertilizer application versus land use in structuring the soil microbial community. Urea application caused significant decreases in soil microbial biomass and enzyme activities in the three tea Orchards. For the wasteland and forest, soil microbial biomass and enzyme activities significantly increased as a result of N fertilizer application. Urea application caused significant decreases in microbial functional and genetic diversity indices of the three tea Orchards. Moreover, the bacterial and fungal phospholipid fatty acids were found to be changed with urea application. Multivariate analyses consistently showed that land use had a greater effect on soil microbial community diversity than urea application.
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nitrification potentials of chinese tea Orchard Soils and their adjacent wasteland and forest Soils
Journal of Environmental Sciences-china, 2009Co-Authors: Yangmei Gao, Huaiying Yao, Dong Xue, Changyong HuangAbstract:To investigate the nitrifying activities of different soil types, soil samples collected from 8-, 50- and 90-year old tea Orchards, the adjacent wasteland, and 90-year old forest were measured for their nitrification potentials using the conventional soil incubation and the liquid incubation method. Among different soil types, the nitrification potential of soil in tea Orchards was higher than that of wasteland and forest Soils. The slurry shaken liquid incubation method was confirmed to be more accurate and have reliable results than the soil incubation. Interestingly, experimental result revealed that the generally applied pH value of 7.2 for the liquid media was not the optimal pH for these acid Soils with a strong buffer capacity. This suggested that tea Orchard Soils may have nitrifiers requiring pH-neutral condition for the best activity. Our data also showed that treatment with the commonly used nitrogen fertilizer urea significantly improved nitrification potential of the Soils; such enhancement effect was stronger on all of three tea Orchard Soils than on wasteland and forest Soils, and also stronger on the younger (8- and 50-year old) tea Orchard Soils than on the older one (90-year old).
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microbial biomass n mineralization and nitrification enzyme activities and microbial community diversity in tea Orchard Soils
Plant and Soil, 2006Co-Authors: Dong Xue, Huaiying Yao, Changyong HuangAbstract:Understanding the chronological changes in soil microbial and biochemical properties of tea Orchard ecosystems after wasteland has been reclaimed is important from ecological, environmental, and management perspectives. In this study, we determined microbial biomass, net N mineralization, and nitrification, enzyme (invertase, urease, proteinase, and acid phosphatase) activities, microbial community diversity assessed by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA polymerase chain reaction (PCR) products, and related ecological factors in three tea Orchard systems (8-, 50-, and 90-year-old tea Orchards), adjacent wasteland and 90-year-old forest. Soil microbial biomass C (Cmic) and activity, i.e., soil basal respiration (Rmic), microbial biomass C as a percent of soil organic C (Cmic/Corg), N mineralization, invertase, urease, proteinase, and acid phosphatase, significantly increased after wasteland was reclaimed; however, with the succeeding development of tea Orchard ecosystems, a decreasing trend from the 50- to 90-year-old tea Orchard became apparent. Soil net nitrification showed an increasing trend from the 8- to 50-year-old tea Orchard and then a decreasing trend from the 50- to 90-year-old tea Orchard, and was significantly higher in the tea Orchards compared to the wasteland and forest. Urea application significantly stimulated soil net nitrification, indicating nitrogen fertilizer application may be an important factor leading to high-nitrification rates in tea Orchard Soils. The Shannon’s diversity index (H) and richness (S) based on DGGE profiles of 16S rRNA genes were obviously lower in all three tea Orchards than those in the wasteland; nevertheless, they were significantly higher in all three tea Orchards than those in the forest. As for the three tea Orchard Soils, comparatively higher community diversity was found in the 50-year-old tea Orchard.
Huaiying Yao - One of the best experts on this subject based on the ideXlab platform.
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links between ammonia oxidizer community structure abundance and nitrification potential in acidic Soils
Applied and Environmental Microbiology, 2011Co-Authors: Huaiying Yao, Graeme W Nicol, Yangmei Gao, Coli D Campbell, Limei Zhang, Ajesh K Singh, James I ProsseAbstract:Ammonia oxidation is the first and rate-limiting step of nitrification and is performed by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the environmental drivers controlling the abundance, composition, and activity of AOA and AOB communities are not well characterized, and the relative importance of these two groups in soil nitrification is still debated. Chinese tea Orchard Soils provide an excellent system for investigating the long-term effects of low pH and nitrogen fertilization strategies. AOA and AOB abundance and community composition were therefore investigated in tea Soils and adjacent pine forest Soils, using quantitative PCR (qPCR), terminal restriction fragment length polymorphism (T-RFLP) and sequence analysis of respective ammonia monooxygenase (amoA) genes. There was strong evidence that soil pH was an important factor controlling AOB but not AOA abundance, and the ratio of AOA to AOB amoA gene abundance increased with decreasing soil pH in the tea Orchard Soils. In contrast, T-RFLP analysis suggested that soil pH was a key explanatory variable for both AOA and AOB community structure, but a significant relationship between community abundance and nitrification potential was observed only for AOA. High potential nitrification rates indicated that nitrification was mainly driven by AOA in these acidic Soils. Dominant AOA amoA sequences in the highly acidic tea Soils were all placed within a specific clade, and one AOA genotype appears to be well adapted to growth in highly acidic Soils. Specific AOA and AOB populations dominated in Soils at particular pH values and N content, suggesting adaptation to specific niches.
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microbial biomass community diversity and enzyme activities in response to urea application in tea Orchard Soils
Communications in Soil Science and Plant Analysis, 2010Co-Authors: Dong Xue, Huaiying YaoAbstract:To improve yield and quality in tea Orchards, a large amount of nitrogen (N) fertilizer is usually applied. Our objective was to evaluate the effect of N application on microbial community and activity in tea Orchard Soils and assess the relative importance of fertilizer application versus land use in structuring the soil microbial community. Urea application caused significant decreases in soil microbial biomass and enzyme activities in the three tea Orchards. For the wasteland and forest, soil microbial biomass and enzyme activities significantly increased as a result of N fertilizer application. Urea application caused significant decreases in microbial functional and genetic diversity indices of the three tea Orchards. Moreover, the bacterial and fungal phospholipid fatty acids were found to be changed with urea application. Multivariate analyses consistently showed that land use had a greater effect on soil microbial community diversity than urea application.
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nitrification potentials of chinese tea Orchard Soils and their adjacent wasteland and forest Soils
Journal of Environmental Sciences-china, 2009Co-Authors: Yangmei Gao, Huaiying Yao, Dong Xue, Changyong HuangAbstract:To investigate the nitrifying activities of different soil types, soil samples collected from 8-, 50- and 90-year old tea Orchards, the adjacent wasteland, and 90-year old forest were measured for their nitrification potentials using the conventional soil incubation and the liquid incubation method. Among different soil types, the nitrification potential of soil in tea Orchards was higher than that of wasteland and forest Soils. The slurry shaken liquid incubation method was confirmed to be more accurate and have reliable results than the soil incubation. Interestingly, experimental result revealed that the generally applied pH value of 7.2 for the liquid media was not the optimal pH for these acid Soils with a strong buffer capacity. This suggested that tea Orchard Soils may have nitrifiers requiring pH-neutral condition for the best activity. Our data also showed that treatment with the commonly used nitrogen fertilizer urea significantly improved nitrification potential of the Soils; such enhancement effect was stronger on all of three tea Orchard Soils than on wasteland and forest Soils, and also stronger on the younger (8- and 50-year old) tea Orchard Soils than on the older one (90-year old).
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microbial biomass n mineralization and nitrification enzyme activities and microbial community diversity in tea Orchard Soils
Plant and Soil, 2006Co-Authors: Dong Xue, Huaiying Yao, Changyong HuangAbstract:Understanding the chronological changes in soil microbial and biochemical properties of tea Orchard ecosystems after wasteland has been reclaimed is important from ecological, environmental, and management perspectives. In this study, we determined microbial biomass, net N mineralization, and nitrification, enzyme (invertase, urease, proteinase, and acid phosphatase) activities, microbial community diversity assessed by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA polymerase chain reaction (PCR) products, and related ecological factors in three tea Orchard systems (8-, 50-, and 90-year-old tea Orchards), adjacent wasteland and 90-year-old forest. Soil microbial biomass C (Cmic) and activity, i.e., soil basal respiration (Rmic), microbial biomass C as a percent of soil organic C (Cmic/Corg), N mineralization, invertase, urease, proteinase, and acid phosphatase, significantly increased after wasteland was reclaimed; however, with the succeeding development of tea Orchard ecosystems, a decreasing trend from the 50- to 90-year-old tea Orchard became apparent. Soil net nitrification showed an increasing trend from the 8- to 50-year-old tea Orchard and then a decreasing trend from the 50- to 90-year-old tea Orchard, and was significantly higher in the tea Orchards compared to the wasteland and forest. Urea application significantly stimulated soil net nitrification, indicating nitrogen fertilizer application may be an important factor leading to high-nitrification rates in tea Orchard Soils. The Shannon’s diversity index (H) and richness (S) based on DGGE profiles of 16S rRNA genes were obviously lower in all three tea Orchards than those in the wasteland; nevertheless, they were significantly higher in all three tea Orchards than those in the forest. As for the three tea Orchard Soils, comparatively higher community diversity was found in the 50-year-old tea Orchard.