Paddy fields are subjected to fluctuating water regimes as a result of the alternate drying and wetting water management, which often incurs a sensitive change in N2O emissions from paddy soils. However, how the soil moisture regulates the emission of N2O from paddy soil remains uncertain. In this study, three incubation experiments were designed to study the effects of constant and fluctuating soil moisture on N2O emission and the sources of N2O emission from paddy soil. Results showed that the N2O emission from paddy soil at 100 % WHC (water-holding capacity) was higher than that at 40, 65, 80, 120, and 160 % WHC, indicating that 100 % WHC was the optimum soil moisture content for N2O emission under the incubation experiment. Small peak of N2O flux appeared when the soil moisture content from 250 % WHC decreased near to 100 % WHC, lower than that triggered by nitrogen (N) fertilization, which was mainly owing to the low NH4+ concentration at this period. Nitrification dominated the emissions of N2O from paddy soil at 250 % WHC (54.96 %), higher than that of nitrification-coupled denitrification (6.74 %) and denitrification (38.3 %). The contribution of denitrification to N2O emissions (44.10 %) was equivalent to that of nitrification (44.45 %) in soil at 100 % WHC, which was higher than that of 250 % WHC treatment. In conclusion, the finding suggested that the peak of N2O in paddy soils during midseason aeration could be attributed to the occurrence of optimum soil moisture under sufficient N availability, favorable for the production and accumulation of N2O. 相似文献
Apple Glomerella leaf spot (GLS) is a severe fungal disease that damages apple leaves during the summer in China. Breeding new apple varieties that are resistant to the disease is considered the best way of controlling GLS. Fine mapping and tightly linked marker are critically essential for the preselection of resistant seedlings. In this study, a population of 207 F1 individuals derived from a cross between ‘Golden Delicious’ and ‘Fuji’ was used to construct a fine simple sequence repeat (SSR)‐based genetic linkage map. The position of Rgls, a locus responsible for resistance to GLS, was identified on apple linkage group (LG) 15 using SSR markers CH05g05 and CH01d08, which was adapted from a published set of 300 SSR markers that were developed using the bulked segregant analysis (BSA) method. These two SSR markers flanked the gene, and its recombination rate was 8.7% and 23.2%, respectively. A total of 276 newly developed SSR markers around the target region and designed from the genome apple assembly contig of LG15 were screened. Only nine of these were determined to be linked to the Rgls locus. Thus, a total of 11 SSR markers were in linkage with Rgls, and mapped at distances ranging from 0.5 to 33.8 cM. The closest marker to the Rgls locus was S0405127, which showed a genetic distance of approximately 0.5 cM. The first mapping of the gene Rgls was constructed, and the locations of the 11 effective primers in the ‘Golden Delicious’ apple genome sequence were anchored. This result facilitates better understanding of the molecular mechanisms underlying the trait of resistance to GLS and could be used in improving the breeding efficiency of GLS‐resistant apple varieties. 相似文献
AIM: To evaluate specific metabolomics profiles in the serum of patients with chronic mountain sickness (CMS) and to explore the potential metabolic biomarkers in the native Tibetans living on the Qinghai-Tibet Pla-teau.METHODS: A gas chromatography time-of-flight mass spectrometry (GC-TOF-MS) approach as a metabolomics technique was used to evaluate metabolic differences. The native Tibetan CMS patients (n=10) and healthy Tibetan controls (n=10) were enrolled from YuShu in Qinghai province in this study. The serum samples were collected and analyzed by GC-TOF-MS coupled with a series of multivariate statistical analyses such as principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal partial least squares discriminant analysis (OPLS-DA).RESULTS: The intergroup differences between CMS patients and control subjects have been observed. A list of differential metabolites and several top altered metabolic pathways have been identified. The levels of fumaric acid, an intermediate in the tricarboxylic acid (TCA) cycle, and inosine were highly upregulated in the CMS patients, suggesting a greater effort to hypoxic adaptation in high elevation area. Other differential metabolites, such as methyl phosphate, 2-ketoadipate, lyxose and phytanic acid were also identified. Importantly, the differential metabolites possessed higher area under the ROC curve (AUC) values, indicating an excellent clinical ability for the prediction of CMS. Increased levels of amino acids (isoleucine, glycine, serine, L-cysteine, citrulline and trimethyllysine) were detected in CMS group, yet significantly decreased levels of sulfuric acid, oxamic acid, lyxose and glutamine were also detected in CMS group than those in control group. At the same time, the levels of ribose and glucose-1-phosphate were markedly elevated in CMS group (P<0.05).CONCLUSION: The metabolic activities are significantly altered in the serum of CMS patients. High altitude hypoxia may act on the disturbed glucose metabolism and amino acid metabolism in part of the Tibetan triggered by CMS. 相似文献
The cover image is based on Research Article Field evaluation of an unmanned aerial vehicle (UAV) sprayer: effect of spray volume on deposition and the control of pests and disease in wheat by Guobin Wang et al., DOI: 10.1002/ps.5321 . Illustration Credit: Guobin Wang, Yubin Lan, and Yuxing Han.