Northwest A & F University
  • Yangling, Shaanxi, China
Recent publications
As an essential way to enhance farmers’ self-development ability, off-farm employment plays an indispensable role in farmers’ multidimensional poverty reduction in many countries. Employing a survey of 1926 farmers in five provinces of the Yellow River Basin in China, this paper examined the multi-dimensional poverty reduction effect of off-farm employment and the heterogeneous influence of different dimensions of off-farm employment (modes, levels, distances and frequency). The results showed that (1) although absolute poverty in the income dimension was largely eliminated in the Yellow River Basin, the poverty in social resources, transportation facilities, employment security were the key bottlenecks restricting farmers’ self-development. (2) The province with the best multidimensional poverty reduction effect for non-farm employment was Shaanxi, with the largest contribution to employment security. (3) Improving off-farm employment level, distance and time can significantly alleviate the multi-dimensional poverty of farmers. Therefore, to lessen the multi-dimensional poverty of farmers in the Yellow River Basin, it is necessary to focus on the governance of multi-dimensional key poverty-stricken areas, such as the middle and upper courses of the Yellow River, adopting multidimensional poverty alleviation strategy of off-farm employment according to local conditions, working on the farmers’ deficiencies in social resources, mobility, employment security, and deepening the effect of off-farm employment on benefiting farmers and helping the poor.
Under global warming, fire and the season in which the fire occurs both have important impacts on grassland plant biomass. Still, the effect of fire on below-ground biomass (BB) along a natural aridity gradient and the main impact factors remain unclear. Here, we conducted a fire manipulation experiment (including un-fired, autumn fire and spring fire treatments) to investigate the effects of prescribed fire on BB and its critical determinants along a transect of grassland in northern China. BB had different response strategies in different aridity regions and fire seasons, despite above-ground biomass (AB) and root-shoot ratio were not significantly affected by fire. General linear regression models revealed that the fire changed the trend of increasing BB to decreasing along increasing aridity (p < 0.05). Random forest model (RFM) and partial correlations revealed that the BB was primarily influenced by aridity, followed by the nitrogen (N) and phosphorus (P) concentration ratio of AB under un-fired disturbance. For autumn fire, the BB was primarily influenced by below-ground biomass carbon concentration (BB c), followed by the C and N concentration ratio of BB. For spring fire, the BB was primarily influenced by soil temperature (ST), followed by aridity and soil total phosphorus concentration (Soil p). Furthermore, partial least squares path model (PLS-PM) revealed that autumn fires weakened the effects of environmental factors on BB, while spring fires enhanced the effects of soil nutrients on BB. These suggested that fire disrupted the original stable nutrient dynamics of BB. Our results suggested that fire promoted the growth of BB in relatively humid areas (aridity = 0.51-0.53) while inhibited the growth of BB in relatively arid areas (aridity = 0.68-0.74). BB c and ST may be key drivers of BB after prescribed fire in autumn and spring.
Information processing theory was applied to explore how external information processing and internal information sharing affect a firm's choice of a green strategy. Analyses of two datasets from Chinese manufacturing firms reveal that environment scanning and inter-functional coordination are important drivers for the adoption of a green strategy. Specifically, firms that engage in extensive environment scanning tend to adopt reactive as opposed to proactive green strategies, whereas firms with effective inter-functional coordination mechanisms tend to adopt proactive rather than reactive green strategies. An entrepreneurial orientation plays a complementary role in a firm's choice of green strategy. It increases the likelihood that a firm will adopt proactive rather than reactive green strategies, and it further strengthens the influences of environment scanning and inter-functional coordination. Overall, these findings offer significant implications for firms regarding how and under what conditions they should adopt green strategies.
This research performed the process optimization of wheat flour crisp puffing by radio frequency (RF) and investigated the accompanying property changes of starch. Experiments were performed in a 6 kW, 27.12 MHz pilot‐scale RF system. The results showed that the volume expansion was highest (220%) when the conditions were employed as follows: electrode gap (115 mm); height of the sample (55 mm); initial moisture content of the sample (30%). Under these conditions, the samples were puffed at 120 s by RF, and changes in the starch properties were further observed. The results showed that the structure of the starch was destroyed, changing from oval and spherical in shape to fragmented. The crystal type of the starch changed from A to A + V types. Its crystal order was reduced, and the Fourier‐infrared spectrum showed that the ratio of (1048/1022) cm ⁻¹ decreased from 1.142 to 1.047. The crystallinity decreased from 48.27% to 17.57%. These changes will help starch digestion and absorption in human body. These results indicated that RF puffing could become a potential development method for puffed snacks. Practical Application In this study, the processes of radio frequency puffing wheat flour chips were optimized, and the changes of starch properties during puffing were studied. Therefore, this research provided a theoretical basis for the industrial application of radio frequency puffing.
Over the past three decades, there has been a significant global climate change characterized by an increase in the intensity and frequency of extreme climate events. The vegetation status in Qinghai Province has undergone substantial changes, which are more pronounced than other regions in the Qinghai-Tibet Plateau. However, a clear understanding of the response characteristics of plateau vegetation to extreme climate events is currently lacking. In this study, we investigated the response of net primary productivity (NPP) to different forms of extreme climate events across regions characterized by varying levels of aridity and elevation gradients. Specifically, we observed a significant increase in NPP in relatively arid regions. Our findings indicate that, in relatively arid regions, single episodes of high-intensity precipitation have a pronounced positive effect (higher correlation) on NPP. Furthermore, in high-elevation regions (4000–6000 m), both the intensity and frequency of precipitation events are crucial factors for the increase in regional NPP. However, continuous precipitation can have significant negative impacts on certain areas within relatively wet regions. Regarding temperature, a reduction in the number of frost days within a year has been shown to lead to a significant increase in NPP in arid regions. This reduction allows vegetation growth rate to increase in regions where it was limited by low temperatures. Vegetation conditions in drought-poor regions are expected to continue to improve as extreme precipitation intensifies and extreme low-temperature events decrease.
Symbiotic systems of sap-feeding auchenorrhynchan insects of the order Hemiptera provide a unique perspective for uncovering complicated insect-microbe symbiosis. Previous evidence suggested that cicadas lacking the symbiont Hodgkinia harbor Sulcia in the bacteriomes and the yeast-like fungal symbiont (YLS) in the fat bodies; however, YLSs were also detected from the bacteriome sheath in three cicada species which separately belong to two phylogenetically closely related tribes, Sonatini and Polyneurini. We comprehensively investigated the symbionts associated with bacteriomes and fat bodies in Sonatini and Polyneurini and analyzed the co-phylogeny between 65 cicada species and related symbionts ( Sulcia and YLSs). We revealed that YLSs can commonly colonize the bacteriome sheath besides the fat bodies in these two tribes. Although the phylogeny of YLSs associated with Sonatini, Polyneurini, and some other taxa is locally concordant with that of host cicadas, relationships of YLSs harbored in different host lineages are generally incongruent with that of Cicadidae. More independent replacement events in the loss of Hodgkinia /acquisition of YLS were revealed in Cicadidae, reinforcing the hypothesis that the pathogenic ancestor of YLSs independently infected different lineages of host cicadas. The phylogeny of the very conservative Sulcia generally mirrors the host phylogeny, but Sulcia associated with some taxa (e.g., Sonatini, Platypleurini) of Cicadidae are incongruent with their hosts. This indicates that genetic variation of Sulcia occurred in these cicada lineages. Results of this study contribute to a better understanding of symbiont colonization in the symbiotic system of auchenorrhynchan insects and co-evolutionary relationships between Auchenorrhyncha and related symbionts. IMPORTANCE Obligate symbionts in sap-sucking hemipterans are harbored in either the same or different organs, which provide a unique perspective for uncovering complicated insect-microbe symbiosis. Here, we investigated the distribution of symbionts in adults of 10 Hodgkinia -free cicada species of 2 tribes (Sonatini and Polyneurini) and the co-phylogeny between 65 cicada species and related symbionts ( Sulcia and YLSs). We revealed that YLSs commonly colonize the bacteriome sheath besides the fat bodies in these two tribes, which is different with that in most other Hodgkinia -free cicadas. Co-phylogeny analyses between cicadas and symbionts suggest that genetic variation of Sulcia occurred in Sonatini and some other cicada lineages and more independent replacement events in the loss of Hodgkinia /acquisition of YLS in Cicadidae. Our results provide new information on the complex relationships between auchenorrhynchans and related symbionts.
Score This study identifies the coding gene ( aldB ) of acetolactate decarboxylase (ALDC) as an important regulatory gene of the intracellular pH in Lactobacillus reuteri (L. reuteri), uncovering the important role of ALDC in regulating intracellular pH, morphological features, and antagonism properties in the probiotic organism L. reuteri . Methods and Results The aldB mutant (ΔaldB) of L. reuteri is established using the homologous recombination method. Compare to the wild‐type (WT) strain, the ΔaldB strain shows a smaller body size, grows more slowly, and contains more acid in the cell cytoplasm. The survival rate of the ΔaldB strain is much lower in low pH and simulated gastric fluid (SGF) than that of the WT strain, but higher in simulated intestinal fluid (SIF). The antagonism test demonstrates the ΔaldB strain can inhibit Listeria monocytogenes ( L. monocytogenes ) and Salmonella more effectively than the WT strain. Additionally, there is a dramatic decrease in the adhesion rate of Salmonella to Caco‐2 and HT‐29 cells in the presence of the ΔaldB strain compared to the WT strain. Simultaneously analyze, the auto‐aggregation, co‐aggregation, cell surface hydrophobicity (CSH), hemolytic, temperature, NaCl, oxidative stress, and antibiotic susceptibility of the ΔaldB strain are consistent with the features of probiotics. Conclusion This study highlights that the aldB gene plays a significant role in the growth and antibacterial properties of L. reuteri .
Oolong tea has gained great popularity in China due to its pleasant floral and fruity aromas. Although numerous studies have investigated the aroma differences across various tea cultivars, the genetic mechanism is unclear. This study performed multiomics analysis of three varieties suitable for oolong tea and three others with different processing suitability. Our analysis revealed that oolong tea varieties contained higher levels of cadinane sesquiterpenoids. PanTFBS was developed to identify variants of transcription factor binding sites (TFBSs). We found that the CsDCS gene had two TFBS variants in the promoter sequence and a single nucleotide polymorphism (SNP) in the coding sequence. Integrating data on genetic variations, gene expression, and protein- binding sites indicated that CsDCS might be a pivotal gene involved in the biosynthesis of cadinane sesquiterpenoids. These findings advance our understanding of the genetic factors involved in the aroma formation of oolong tea and offer insights into the enhancement of tea aroma.
Combining multiple features of UAV-based multispectral images with the stacking ensemble model, to improve the feasibility and accuracy of evaluating water stress in winter wheat. UAV-based multispectral images of winter wheat with different moisture treatments were acquired, from which the features such as spectrum, texture, and color moments were extracted. The soil moisture content (SMC) as well as fuel moisture content (FMC), plant moisture content (PMC), and above-ground biomass (AGB) were collected for charging the degree of water stress. The basic models were used to build ensemble models such as stacking and weighted stacking (WE-stacking), and we estimated SMC, FMC, PMC and AGB combined with multiple features. The performance of these models was evaluated. The more severe the water stress, the lower values of SMC, FMC, PMC and AGB were obtained with estimation models. The performance of estimation models based on multi-feature fusion outperformed single feature in the evaluation of winter-wheat water stress. In the estimation of SMC, both stacking and WE-stacking models performed better than the basic models. Compared to the stacking model, the WE-stacking model had higher accuracy, with R2 increased between 1.98% and 3.62% at different soil depths. The WE-stacking model with multi-feature fusion still had sufficient stability and high accuracy in FMC, PMC and AGB estimation, with R2 of 0.866, 0.881 and 0.884, respectively. The multi-feature fusion of UAV multispectral images combined with WE-stacking model has great application potential and provides technical support in evaluating crop water stress.
• N fertilizer altered bacterial community compositions by changing soil nutrients. • Bacterial ammonia oxidation became predominated with the increasing N rate. • Excessive N input caused the information of a more complex microbial network. • Intensified microbial competition by excessive N was due to negative link increase. Nitrogen (N) fertilization drives the structure and function of soil microbial communities, which are crucial for regulating soil biogeochemical cycling and maintaining ecosystem stability. Despite the N fertilizer effects on soil microbial composition and diversity have been widely investigated, it is generally overlooked that ecosystem processes are carried out via complex associations among microbiome members. Here, we examined the effects of five N fertilization levels (0, 135, 180, 225, and 360 kg N ha−1) on microbial co-occurrence networks and key functional taxa such as ammonia-oxidizers in paddy soils. The results showed that N addition altered microbial community composition, which were positively related to soil total N and available phosphorus (P) contents. The abundance of ammonia-oxidizing archaea (AOA) significantly decreased after N addition, whereas ammonia-oxidizing bacteria (AOB) increased in N360 treatment. Compared with low-N group (N0 and N135), the high-N group (N225 and N360) shaped more complex microbial webs and thus improved the stability of the microbial community. Partial least squares path modeling further revealed that N fertilizer had a higher effect on microbial network complexity in the high-N group (0.83) than the low-N group (0.49). Although there were more positive links across all microbial networks, the proportion of negative links significantly increased in the high-N network, suggesting that excess N addition aggravated the competition among microbial species. Disentangling these interactions between microbial communities and N fertilization advances our understanding of biogeochemical processes in paddy soils and their effects on nutrient supply to rice production. Our findings highlighted that highly N-enriched paddy soils have more stable microbial networks and can better sustain soil ecological functions to cope with the ongoing environmental changes.
Wheat root diseases are typically caused by complex soilborne fungal pathogens. Biocontrol can be effective, but it can be difficult for a single biocontrol strain to achieve a good control effect. Previously, the gene for antibiotic phenazine-1-carboxylic acid (PCA) from Pseudomonas synxantha 2-79 was introduced into Pseudomonas fluorescens HC1-07, which produces cyclic lipopeptide (CLP) naturally. In the present study, recombinant strain HC1-07PHZ produced both PCA and CLP and maintained a similar population size as wild type strain HC1-07 in the wheat rhizosphere. Compared with that of HC1-07, the recombinant strain had a stronger inhibitory effect on pathogens of Rhizoctonia solani AG-8 C1, AG-2-1, Rhizoctonia cerealis R0301, and Fusarium graminearum Schwabe in vitro. When used as a seed-coating treatment, the recombinant strain inhibited Rhizoctonia root rot of wheat, as did strain HC1-07. However, the dose of HC1-07PHZ was 1000-fold less. Liquid chromatography-tandem mass spectrometry (LC–MS/MS) revealed compounds such as pipecolic acid, arachidonic acid, and acetylcysteine in wheat root soil inoculated with three strains (2-79, HC1-07, and HC1-07PHZ) used as seed-coating agents, respectively. The composition of these molecules was very different for different bacteria. These metabolites may trigger plant defense responses, promote plant growth, or combat pathogenic fungi, but analysis of the enrichment pathway showed that these metabolites were mainly from signal pathways involved in plant detoxification and various biochemical processes. In summary, our study showed that recombinant strain HC1-07PHZ greatly improved the biocontrol effect against Rhizoctonia root rot and Fusarium crown rot of wheat.
BACKGROUND SYP‐34773 is a low‐toxicity pyrimidine amine compound, which was synthesized by modifying the lead compound diflumetorim. Previous literature has shown that it can strongly inhibit the mycelial growth of several important plant pathogens, including Phytophthora litchii . However, the resistance risk of SYP‐34773 has not been reported for P. litchii . RESULTS The mean EC 50 value of SYP‐34773 against the mycelial growth of 111 P. litchii isolates was 0.108 ± 0.008 μg mL ‐1 , which can be used as the baseline sensitivity for SYP‐34773 resistance detection in the future. Six mutants were obtained from two parental strain through fungicide induction, whose resistance factors fell between 194 and 687‐fold, with stability. Results regarding mycelial growth, sporangial production, sporangial germination, zoospore release, cystspore germination, and pathogenicity showed that the mutants’ compound fitness index values were significantly lower than those of their parental isolate. Furthermore, there was no cross‐resistance between SYP‐34773 and diflumetorim in P. litchii . Significant inhibition of the mitochondrial complex I enzyme activity in two wild‐type P . litchii isolates, but not in mutants, was observed upon treatment with SYP‐34773. CONCLUSION The resistance risk of SYP‐34773 in P. litchii is moderate, and resistance management strategies should be adopted in field use. SYP‐34773 is a mitochondrial complex I inhibitor, and SYP‐34773‐resistant P. litchii isolates did not show cross‐resistance against diflumetorim. This article is protected by copyright. All rights reserved.
For molecular breeding of future apples, wild apple (Malus sieversii), the primary progenitor of domesticated apples, provides abundant genetic diversity and disease-resistance traits. Valsa canker (caused by the fungal pathogen Valsa mali) poses a major threat to wild apple population as well as to cultivated apple production in China. In the present study, we developed an efficient system for screening disease-resistant genes of M. sieversii in response to V. mali. An optimal agrobacterium-mediated transient transformation of M. sieversii was first used to manipulate in situ the expression of candidate genes. After that, the pathogen V. mali was inoculated on transformed leaves and stems, and 3 additional methods for slower disease courses were developed for V. mali inoculation. To identify the resistant genes, a series of experiments were performed including morphological (incidence, lesion area/length, fungal biomass), physiological (H2O2 content, malondialdehyde content), and molecular (Real-time quantitative Polymerase Chain Reaction) approaches. Using the optimized system, we identified two transcription factors with high resistance to V. mali, MsbHLH41 and MsEIL3. Furthermore, 35 and 45 downstream genes of MsbHLH41 and MsEIL3 were identified by screening the V. mali response gene database in M. sieversii, respectively. Overall, these results indicate that the disease-resistant gene screening system has a wide range of applications for identifying resistant genes and exploring their immune regulatory networks. Supplementary Information The online version contains supplementary material available at 10.1186/s13007-023-01115-w.
With the proposal of industry 4.0, all kinds of advanced technologies provide more ways of green economy for countries. This paper aims to design a green economy evaluation indicators framework and construct an integration method. Those can not only comprehensively evaluate the development level of the green economy of each region, but also reflect the evolution process of the regional green economy. We found China's RGED showed an "inverted U-shaped" trend from 2000 to 2015 and the RGED of China's 31 provinces has spatial heterogeneous effects and presents an “east-central-west” decreasing characteristic. This characteristic cannot be separated from the impact of regional resource features, scientific and technological level, local development policies, etc. Those findings can put forward suggestions for China's green economic development.
Energy transition has brought widespread attentions to the concept of coupled utilization of the geothermal and solar energy. This paper provides an integrated assessment on developing a nanofluid geothermal-photovoltaic hybrid system that addresses the multi-objective optimization and multi-criteria evaluation difficulties. The coupling system design and dispatch are optimized by considering the multiple objectives from the microscopic particles to the system. The life cycle cost, levelized cost of energy, levelized cost of heat, and the irreversibility are introduced in the optimization stage. The optimization parameters include the pipe arrangement, type of nanoparticles, and the concentration of the nanoparticles in nanofluids. A combined analysis including the energy, exergy, economy, and the environment is proposed to evaluate the various objectives and cases. The results show that the combination of 2% Al 2 O 3 nanofluid and spiral pipe has the optimum performance. The monocrystalline solar panels with the nanofluids-aided heat pump create the least CO 2 emissions (550 kg/year), the least LCOE (198.18 $), and the highest exergy efficiency. However, the LCOH (211.78 $/MWh) is still much high. Only when the electricity cost is higher than 0.11$/kWh, the proposed coupling system would show competitiveness. In summary, these results effectively prove the robustness and superiority of the hybrid system.
Different tillage and residue management practices can strongly impact soil structure stability and soil organic carbon (SOC) sequestration. However, the detailed information about the aggregate stability, SOC protection, and mineralization within aggregates are still lacking. Using aggregate fractionation with laboratory incubation, we investigated aggregate-associated SOC, soil structural stability, and SOC mineralization in rice-wheat rotation under different tillage treatments: CT0 (pud-dled rice, conventional wheat − residue); CTR (puddled rice, conventional wheat + residue); NT0 (direct rice seeding, zero-tilled wheat − residue); and NTR (direct rice seeding, zero-tilled wheat + residue). NTR significantly enhanced the large macro-aggregate fraction (> 2 mm) at the 0-45 cm soil layer and macro-aggregate-associated SOC at the 0-15 cm soil layer. However, CTR enhanced the macro-aggregate-associated SOC at the 15-30 cm layer. Notably, the mean weight diameter (~8%) and geometric mean diameter (~24%) were higher under NTR than those under other treatments, and the effect was more pronounced in 30-45 cm layer. The highest average cumulative carbon mineralization C m (~9%) was observed in macro-aggregates (> 2 mm) than micro-aggregates (< 2 mm). With regard to tillage systems, the C m was higher under NTR compared to other treatments. However, C m at the 15-30 cm layer was higher (~22%) under CTR than that in other treatments. Notably, a positive relationship was found between total carbon input and soil aggregation. Specifically, carbon input of NT0, NTR, and CTR increased > 2 mm aggregates at 0-15 cm, while carbon input of CTR increased > 2 mm at 15-30 cm soil depth. Overall, no tillage with residue return (NTR) could enhance the soil macro-aggregation and associated SOC accumulation by decreasing SOC mineralization in rice-wheat double cropping system.
Background and aims Dissolved organic matter (DOM) is a vital bioactive component in soil nutrient cycling. However, the dynamics of its characteristics and composition along the soil profile during desertification reversal are poorly understood. Methods Soil samples were gathered from shrub and arbor forests that have been established for 25, 35, 46, and 56 years on semifixed sand of Mu Us Sandy Land. The evolution of DOM composition and chemical properties were explored by ultraviolet-visible and fluorescence spectrophotometry. Results After 56 revegetation years, DOM increased significantly. In arbor lands, DOM was impacted mainly by dissolved organic carbon, with mean concentrations increasing from 58.89 mg·kg-1 to 131.95 mg·kg-1 in 0-100 cm soil profile. In the shrubland, changes in dissolved organic nitrogen were more remarkable, with mean concentrations increasing from 3.43 mg·kg⁻¹ to 6.82 mg·kg⁻¹ in 0-100 cm soil profile. Concurrently, as soil depth increased, noticeably decreased in the proportion of humic-like components within DOM, while protein-like components displayed an upward trend. The chemical properties of DOM in arbor lands display a higher proportion of hydrophobic substances along with an elevated aromaticity and humification degree. Conversely, in shrubland, the DOM composition exhibits a higher proportion of tryptophan components that are more available for microbial metabolism. Correlation analysis showed that DOM content and specific environmental factors (including soil depth, vegetation type, and afforestation age) profoundly affected soil DOM properties. Conclusions The DOM in arbor land and surface soil layer were more humified and relatively stable. Conversely, the DOM in shrubland and deeper soil layers contains more bioactive substances for microbial utilization.
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6,140 members
Mukesh Kumar Awasthi
  • Department of Resource and Environmental Science
Yongqing Ma
  • Institute of Soil and Water Conservation
Fengbao Zhang
  • Institute of Soil and Water Conservation
Xu Shutu
  • College of Agronomy
Information
Address
3 Taicheng Road, 712100, Yangling, Shaanxi, China
Head of institution
吴普特(Pute Wu)
Website
http://www.nwafu.edu.cn/ ; https://en.nwsuaf.edu.cn/