Gao Y.,Jiangsu Academy of Agricultural Sciences |
Gao Y.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Zhang Z.,Jiangsu Academy of Agricultural Sciences |
Liu X.,Jiangsu Academy of Agricultural Sciences |
And 7 more authors.
Small and shallow water bodies often exhibit high rates of biogeochemical activities, yet have not received much attention. Here we test the hypothesis that there is strong diurnal stratification of physicochemical characteristics in a hyper-eutrophic pond, which would lead to a heterogeneous distribution of gas production via biological processes along vertical profile of water column. Accordingly, we focused on quantifying the seasonal and diurnal dynamics of nutrients (NO3 -, NH4+, total dissolved nitrogen TDN, PO4 3-, total dissolved phosphorus TDP), physicochemical environment factors (DO, pH, light intensity, Chlorophyll-a) and gas emission (N2, N2O, O2, CH4) in the vertical profile of an ultra-eutrophic pond located at the subtropical climate zone, China. The strong and persistent stratification of several parameters at the resolution of centimeters along vertical profile of water was observed in summer and autumn. Interestingly, the surface water and sediment-water interface produced much more gas than the middle layers of water column. The quantity and composition of gas collected from the surface water were greatly affected by O2 production, which followed the diurnal cycle of sunlight intensity. Other biological processes, e.g. nitrification and/or denitrification, may also have contributed to the heterogeneous gas production as high N2 and N2O fluxes were detected in the surface layer and sediment-water interface. CH4 production was mainly from the sediment-water interface, especially in summer when the bottom layer developed very low DO concentrations due to strong stratification. Our results demonstrate that besides the unexpectedly long and strong thermal and physicochemical stratification, the shallow eutrophic pond can undergo significant vertical heterogeneity of gas emission due to the strong diurnal stratification of these physicochemical parameters. © 2015. Source
Cao Y.,Jiangsu Academy of Agricultural Sciences |
Cao Y.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Wang J.,Jiangsu Academy of Agricultural Sciences |
Wu H.,Jiangsu Academy of Agricultural Sciences |
And 4 more authors.
Applied Soil Ecology
The rapid development of biogas production will result in increased use of biogas slurry (BS) as organic fertilizer. However, side effects such as suppression of soilborne diseases are not yet well investigated and understood. Therefore, the objectives of the study were to evaluate the effects of biogas slurry application on suppression of Fusarium wilt disease of watermelon and its relationship with soil chemical and microbiological properties. Pot and field experiments were conducted to compare effects of biogas slurry application on Fusarium wilt disease suppression of watermelon in soil with a moisture content of 60% water holding capacity (WHC) or flooded continuously. Fusarium wilt was significantly suppressed in soil from biogas slurry amended plots. Biogas slurry flooding enhanced the degree of suppression in the pot experiment. Moreover, the biogas slurry treatment also significantly suppressed Fusarium wilt in the field with a disease index of 33.2% compared with 69.6% in water treatment. Biogas slurry strongly reduced the pathogen population in rhizosphere soil. The populations were decreased by 43.1% and 95.9% in the biogas slurry moist and flooding treatments, respectively. Biolog data indicated that average well color development (AWCD) and Shannon-weaver index were increased significantly in biogas flooding treatment. Principal component analysis showed that Fusarium wilt was negatively correlated with NH4 +-N, available K (AK), water-soluble carbon (DOC), water soluble nitrogen (DON) and phenolic acid (PA) contents in soil and positively correlated to soil pH and soil redox potential (Eh). Microbial communities, in general, did not significantly correlate with disease suppression. © 2016 Elsevier B.V. Source
Qiu J.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Xu J.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Shi J.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base
European Journal of Plant Pathology
Members of the Fusarium graminearum species complex (FGSC) cause Fusarium head blight in small cereal grains all over the world. To determine the species and trichothecene chemotype composition and population structure of FGSC in Jiangsu and Anhui provinces, an area where epidemics occur regularly, 891 isolates were collected in two consecutive years (2011 and 2012) and characterized with species- and chemotype-specific polymerase chain reaction. Of the 891 isolates typed, 83 were F. graminearum sensu stricto (s. str.) and 808 were F. asiaticum. All 83 F. graminearum s. str. isolates were of a 3ADON (26.51 %) or 15ADON (73.49 %) type, while F. asiaticum isolates included 696 3ADON producers, 46 15ADON producers, and 66 NIV producers. Eight variable number tandem repeat (VNTR) markers were tested on a representative 384 F. asiaticum isolates from 55 sampling sites. VNTR analysis showed high gene diversity and genotypic diversity but low linkage disequilibrium in both populations Fg2011 and Fg2012 grouped based on the year of collection. Low genetic differentiation (F ST = 0.026) and high gene flow (N m = 15.13) was observed between the two populations and among subpopulations within the same population (N m = 3.53 to 48.37), indicating that few influence of temporal and spatial variations on population differentiation in this area. Similar result was obtained from 3ADON, 15ADON and NIV populations or carbendazim resistant and sensitive populations, indicating that chemotype of Fusarium isolates and carbendazim application had minor influence on population subdivision. © 2014 Koninklijke Nederlandse Planteziektenkundige Vereniging. Source
Gao T.,Jiangsu Academy of Agricultural Sciences |
Gao T.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Gao T.,Key Laboratory of Control Technology and Standard for Agro product Safety and Quality |
Chen J.,Jiangsu Academy of Agricultural Sciences |
And 5 more authors.
Pyruvate dehydrogenase kinase (PDK) is an important mitochondrial enzyme that blocks the production of acetyl-CoA by selectively inhibiting the activity of pyruvate dehydrogenase (PDH) through phosphorylation. PDK is an effectively therapeutic target in cancer cells, but the physiological roles of PDK in phytopathogens are largely unknown. To address these gaps, a PDK gene (FgPDK1) was isolated from Fusarium graminearum that is an economically important pathogen infecting cereals. The deletion of FgPDK1 in F. graminearum resulted in the increase in PDH activity, coinciding with several phenotypic defects, such as growth retardation, failure in perithecia and conidia production, and increase in pigment formation. The ΔFgPDK1 mutants showed enhanced sensitivity to osmotic stress and cell membrane-damaging agent. Physiological detection indicated that reactive oxygen species (ROS) accumulation and plasma membrane damage (indicated by PI staining, lipid peroxidation, and electrolyte leakage) occurred in ΔFgPDK1 mutants. The deletion of FgPDK1 also prohibited the production of deoxynivalenol (DON) and pathogenicity of F. graminearum, which may resulted from the decrease in the expression of Tri6. Taken together, this study firstly identified the vital roles of FgPDK1 in the development of phytopathogen F. graminearum, which may provide a potentially novel clue for target-directed development of agricultural fungicides. © 2016 Gao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source
Wu J.,Jiangsu Academy of Agricultural Sciences |
Wu J.,Key Laboratory of Food Quality and Safety of Jiangsu Province State Key Laboratory Breeding Base |
Wu J.,Jiangsu Center for Evaluation and Detection |
Yu M.,Jiangsu Academy of Agricultural Sciences |
And 18 more authors.
The transgenic wheat line N12-1 containing the WYMV-Nib8 gene was obtained previously through particle bombardment, and it can effectively control the wheat yellow mosaic virus (WYMV) disease transmitted by Polymyxa graminis at turngreen stage. Due to insertion of an exogenous gene, the transcriptome of wheat may be altered and affect root exudates. Thus, it is important to investigate the potential environmental risk of transgenic wheat before commercial release because of potential undesirable ecological side effects. Our 2-year study at two different experimental locations was performed to analyze the impact of transgenic wheat N12-1 on bacterial and fungal community diversity in rhizosphere soil using polymerase chain reaction-denaturing gel gradient electrophoresis (PCR-DGGE) at four growth stages (seeding stage, turngreen stage, grain-filling stage, and maturing stage). We also explored the activities of urease, sucrase and dehydrogenase in rhizosphere soil. The results showed that there was little difference in bacterial and fungal community diversity in rhizosphere soil between N12-1 and its recipient Y158 by comparing Shannon's, Simpson's diversity index and evenness (except at one or two growth stages). Regarding enzyme activity, only one significant difference was found during the maturing stage at Xinxiang in 2011 for dehydrogenase. Significant growth stage variation was observed during 2 years at two experimental locations for both soil microbial community diversity and enzyme activity. Analysis of bands from the gel for fungal community diversity showed that the majority of fungi were uncultured. The results of this study suggested that virus-resistant transgenic wheat had no adverse impact on microbial community diversity and enzyme activity in rhizosphere soil during 2 continuous years at two different experimental locations. This study provides a theoretical basis for environmental impact monitoring of transgenic wheat when the introduced gene is derived from a virus. © 2014 Wu et al. Source