Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Genome-wide identification of small G protein ROPs and their potential roles in Solanaceous family
    Yang, Shuqing ; Yan, Ningning ; Bouwmeester, Klaas ; Na, Ren ; Zhang, Zhiwei ; Zhao, Jun - \ 2020
    Gene 753 (2020). - ISSN 0378-1119
    Genome-wide screening - Phylogenetic analysis - Plant growth and development - Plant immunity - Small GTPase ROPs - Solanaceous family

    Small GTPases function as molecular switches to active or inactive signaling cascades via binding or hydrolyzing GTP. A type of plant specific small GTPases, the ROPs are known to be involved in plant growth, development and immunity. We determined whether ROPs are conserved in Solanaceous species and whether they are involved in plant growth, development and resistance against Phytophthora capsisi. In genome-wide screening, a total of 66 ROPs in six Solanaceous species (SolROPs) were identified, including 16 ROPs in Solanum tuberosum L. (potato), 9 in Solanum lycopersicum L. (tomato), 5 in Solanum melongena L. (eggplant), 9 in Capsicum annuum L. (pepper), 13 in Nicotiana benthamiana Domin and 14 in Nicotiana tabacum L. (tobacco). Phylogenetic analysis revealed that 11 AtROPs and 66 SolROPs fall into five distinct clades (I-V) and hence a novel and systematic gene nomenclature was proposed. In addition, a comprehensive expression analysis was performed by making use of an online database. This revealed that ROP genes are differentially expressed during plant growth and development. Moreover, gene expression of SlROP-II.1 in S. lycopersicum could be significantly induced by P. capsici. Subsequently, SlROP-II.1 and its homologues in N. benthamiana and C. annuum (NbROP-II.1 and CaROP-II.1) were selected for functional analysis using virus-induced gene silencing. Infection assays with P. capsici on silenced plants revealed that SlROP-II.1, NbROP-II.1 and CaROP-II.1 play a role in P. capsici resistance, suggesting conserved function of ROP-II clade across different Solanaceous species. In addition, NbROP-II.1 is also involved in regulating plant growth and development. This study signified the diversity of Solanaceous ROPs and their potential roles in plant growth, development and immunity.

    Improvement in municipal wastewater treatment alters lake nitrogen to phosphorus ratios in populated regions
    Tong, Yindong ; Wang, Mengzhu ; Peñuelas, Josep ; Liu, Xueyan ; Paerl, Hans W. ; Elser, James J. ; Sardans, Jordi ; Couture, Raoul Marie ; Larssen, Thorjørn ; Hu, Hongying ; Dong, Xin ; He, Wei ; Zhang, Wei ; Wang, Xuejun ; Zhang, Yang ; Liu, Yi ; Zeng, Siyu ; Kong, Xiangzhen ; Janssen, Annette B.G. ; Lin, Yan - \ 2020
    Proceedings of the National Academy of Sciences of the United States of America 117 (2020)21. - ISSN 0027-8424
    Anthropogenic source - Aquatic ecosystem - Nutrient balance - Wastewater treatment - Water quality change

    Large-scale and rapid improvement in wastewater treatment is common practice in developing countries, yet this influence on nutrient regimes in receiving waterbodies is rarely examined at broad spatial and temporal scales. Here, we present a study linking decadal nutrient monitoring data in lakes with the corresponding estimates of five major anthropogenic nutrient discharges in their surrounding watersheds over time. Within a continuous monitoring dataset covering the period 2008 to 2017, we find that due to different rates of change in TN and TP concentrations, 24 of 46 lakes, mostly located in China's populated regions, showed increasing TN/TP mass ratios; only 3 lakes showed a decrease. Quantitative relationships between in-lake nutrient concentrations (and their ratios) and anthropogenic nutrient discharges in the surrounding watersheds indicate that increase of lake TN/TP ratios is associated with the rapid improvement in municipal wastewater treatment. Due to the higher removal efficiency of TP compared with TN, TN/TP mass ratios in total municipal wastewater discharge have continued to increase from a median of 10.7 (95% confidence interval, 7.6 to 15.1) in 2008 to 17.7 (95% confidence interval, 13.2 to 27.2) in 2017. Improving municipal wastewater collection and treatment worldwide is an important target within the 17 sustainable development goals set by the United Nations. Given potential ecological impacts on biodiversity and ecosystem function of altered nutrient ratios in wastewater discharge, our results suggest that long-term strategies for domestic wastewater management should not merely focus on total reductions of nutrient discharges but also consider their stoichiometric balance.

    Prevalence of milk fraud in the Chinese market and its relationship with fraud vulnerabilities in the chain
    Yang, Yuzheng ; Zhang, Liebing ; Hettinga, Kasper A. ; Erasmus, Sara W. ; Ruth, Saskia M. Van - \ 2020
    Foods 9 (2020)6. - ISSN 2304-8158
    China - Fourier transform-infrared spectroscopy - Fraud vulnerability - Milk adulteration - Milk composition - One-class classifications

    This study aimed to assess the prevalence of ultra-high-temperature (UHT) processed milk samples suspected of being adulterated on the Chinese market and, subsequently, relate their geographical origin to the earlier determined fraud vulnerability. A total of 52 UHT milk samples purchased from the Chinese market were measured to detect possible anomalies. The milk compositional features were determined by standardized Fourier transform-infrared spectroscopy, and the detection limits for common milk adulterations were investigated. The results showed that twelve of the analysed milk samples (23%) were suspected of having quality or fraud-related issues, while one sample of these was highly suspected of being adulterated (diluted with water). Proportionally, more suspected samples were determined among milks produced in the Central- Northern and Eastern areas of China than in those from the North-Western and North-Eastern areas, while those from the South were in between. Combining the earlier collected results on fraud vulnerability in the Chinese milk chains, it appears that increased fraud prevalence relates to poorer business relationships and lack of adequate managerial controls. Since very few opportunities and motivations differ consistently across high and low-prevalence areas, primarily the improvement of control measures can help to mitigate food fraud in the Chinese milk supply chains.

    Cellular levels and molecular dynamics simulations of estragole DNA adducts point at inefficient repair resulting from limited distortion of the double-stranded DNA helix
    Yang, Shuo ; Diem, Matthias ; Liu, Jakob D.H. ; Wesseling, Sebastiaan ; Vervoort, Jacques ; Oostenbrink, Chris ; Rietjens, Ivonne M.C.M. - \ 2020
    Archives of Toxicology 94 (2020)4. - ISSN 0340-5761 - p. 1349 - 1365.
    DNA adduct - DNA repair efficiency - Estragole - Molecular modeling and simulation

    Estragole, naturally occurring in a variety of herbs and spices, can form DNA adducts after bioactivation. Estragole DNA adduct formation and repair was studied in in vitro liver cell models, and a molecular dynamics simulation was used to investigate the conformation dependent (in)efficiency of N2-(trans-isoestragol-3′-yl)-2′-deoxyguanosine (E-3′-N2-dG) DNA adduct repair. HepG2, HepaRG cells, primary rat hepatocytes and CHO cells (including CHO wild-type and three NER-deficient mutants) were exposed to 50 μM estragole or 1′-hydroxyestragole and DNA adduct formation was quantified by LC–MS immediately following exposure and after a period of repair. Results obtained from CHO cell lines indicated that NER plays a role in repair of E-3′-N2-dG adducts, however, with limited efficiency since in the CHO wt cells 80% DNA adducts remained upon 24 h repair. Inefficiency of DNA repair was also found in HepaRG cells and primary rat hepatocytes. Changes in DNA structure resulting from E-3′-N2-dG adduct formation were investigated by molecular dynamics simulations. Results from molecular dynamics simulations revealed that conformational changes in double-stranded DNA by E-3′-N2-dG adduct formation are small, providing a possible explanation for the restrained repair, which may require larger distortions in the DNA structure. NER-mediated enzymatic repair of E-3′-N2-dG DNA adducts upon exposure to estragole will be limited, providing opportunities for accumulation of damage upon repeated daily exposure. The inability of this enzymatic repair is likely due to a limited distortion of the DNA double-stranded helix resulting in inefficient activation of nucleotide excision repair.

    Syndromes of production in intercropping impact yield gains
    Li, Chunjie ; Hoffland, Ellis ; Kuyper, Thomas W. ; Yu, Yang ; Zhang, Chaochun ; Li, Haigang ; Zhang, Fusuo ; Werf, Wopke van der - \ 2020
    Nature Plants 6 (2020)6. - ISSN 2055-026X
    Intercropping, the simultaneous production of multiple crops on the same field, provides opportunities for the sustainable intensification of agriculture if it can provide a greater yield per unit land and fertilizer than sole crops. The worldwide absolute yield gain of intercropping as compared with sole crops has not been analysed. We therefore performed a global meta-analysis to quantify the effect of intercropping on the yield gain, exploring the effects of crop species combinations, temporal and spatial arrangements, and fertilizer input. We found that the absolute yield gains, compared with monocultures, were the greatest for mixtures of maize with short-grain cereals or legumes that had substantial temporal niche differentiation from maize, when grown with high nutrient inputs, and using multirow strips of each species. This approach, commonly practised in China, provided yield gains that were (in an absolute sense) about four times as large as those in another, low-input intercropping strategy, commonly practised outside China. The alternative intercropping strategy consisted of growing mixtures of short-stature crop species, often as full mixtures, with the same growing period and with low to moderate nutrient inputs. Both the low- and high-yield intercropping strategies saved 16–29% of the land and 19–36% of the fertilizer compared with monocultures grown under the same management as the intercrop. The two syndromes of production in intercropping uncovered by this meta-analysis show that intercropping offers opportunities for the sustainable intensification of both high- and low-input agriculture.
    Computer-assisted terrain sketch mapping that considers the geomorphological features in a loess landform
    Cheng, Yihan ; Yang, Xin ; Liu, Hailong ; Li, Min ; Rossiter, David G. ; Xiong, Liyang ; Tang, Guoan - \ 2020
    Geomorphology 364 (2020). - ISSN 0169-555X
    DEM - Loess landform - Terrain sketch map - Visual hierarchy division - Visual outline generalisation

    In geography, a terrain sketch map is necessary to understand the features and internal structures of a landscape due to its ability to depict key information in a geographical scene using as few lines as possible. Previous computer-drawn sketch maps have focused on the artistic effect rather than on depicting terrain features and landform structures, and thus, they differ considerably from hand-drawn sketch maps by geographers or geologists. This study develops a DEM-based method for terrain sketch mapping that considers the typical feature descriptions of a loess landform and the visual hierarchy expression in line with the law of visual perspective. The method was tested with experiments on two landforms of Chinese Loess Plateau, based on digital elevation models (DEM) with a horizontal resolution of 5 m. In the developed method, first, typical terrain features, including the visual outline, shoulder line, gully and flow lines, are extracted from the DEM. Second, the map is divided into three visual levels in accordance with the data extension and viewing point. Then, terrain feature lines are assigned to different visual levels. Finally, the visual outlines in the distant view are generalized following the law of visual perspective. Results are assessed through a questionnaire with specialists (experts) and students (non-experts). The sketch map was able to characterise loess landforms, and is somewhat similar to traditional hand-drawn maps. The generalisation method realises the near and distant view characteristics of a sketch map, which are detailed and simplified, respectively. The results of the questionnaire also showed that our method presents terrain morphology and geographical scene more accurately and reliably than a hand-drawn sketch map.

    Belowground soil water response in the afforestation-cropland interface under semi-arid conditions
    Huang, Ze ; Yang, Wen Jin ; Liu, Yu ; Shen, Weibo ; López-Vicente, Manuel ; Wu, Gao Lin - \ 2020
    Catena 193 (2020). - ISSN 0341-8162
    Agroforestry system interface - Semi-arid area - Soil water deficit degree - Soil water storage

    Agroforestry is an effective measure to control soil erosion and maintain or increase productivity in semi-arid areas. However, the belowground soil water responses in the afforestation-cropland interface (ACI) is not well known. This study analyzed the variability of soil water storage (SWS) and deficit in three ACIs taking into account the distance between the forest and cropland. The variations of soil water content up to 4 m depth and at five distances from the interface (−5 m (in forest), 0 m (interface), 1 m, 3 m and 5 m (in cropland)) were estimated in three artificial forests (Salix matsudana, Sophora japonica, and Populus cathayana) and their adjacent croplands (maize). The results showed that soil water at the interfaces was significantly affected by forest. This effect was effective up to 160–170 cm of soil depth, and the ACI of S. matsudana had the greatest impact on the farmland soil water. There was no significant relative soil water deficit between 1 and 3 m length, and the ACI of P. cathayana showed the lowest changes in the lateral direction. The SWS of S. japonica in the ACI was clearly higher than the other two artificial forests (P < 0.05). Our findings indicated that S. japonica was the most suitable forest species for agriculture sustainability in the study area. The tree species and the distance between cropland and forest should be considered during the establishment of agroforestry systems. This study provided insights for water conservation and effective management of ACIs in semi-arid areas.

    Methodology matters for comparing coarse wood and bark decay rates across tree species
    Chang, Chenhui ; Logtestijn, Richard S.P. van; Goudzwaard, Leo ; Hal, Jurgen van; Zuo, Juan ; Hefting, Mariet ; Sass-Klaassen, Ute ; Yang, Shanshan ; Sterck, Frank J. ; Poorter, Lourens ; Cornelissen, Johannes H.C. - \ 2020
    Methods in Ecology and Evolution 11 (2020)7. - ISSN 2041-210X - p. 828 - 838.
    asynchronous - dead wood - decomposition - ecological methodology - fragment loss - inner bark thickness - interspecific variation - volume loss

    The importance of wood decay for global carbon and nutrient cycles is widely recognized. However, relatively little is known about bark decay dynamics, even though bark represents up to 25% of stem dry mass. Moreover, bark presence versus absence can significantly alter wood decay rates. Therefore, it really matters for the fate of carbon whether variation in bark and wood decay rates is coordinated across tree species. Answering this question requires advances in methodology to measure both bark and wood mass loss accurately. Decay rates of large logs in the field are often quantified as loss in tissue density, in which case volume depletions of bark and wood can yield large underestimations. To quantify the real decay rates, we assessed bark mass loss per stem surface area and wood mass loss based on volume-corrected density loss. We further defined the range of actual bark mass loss by considering bark cover loss. Then, we tested the correlation between bark and wood mass loss across 20 temperate tree species during 4 years of decomposition. The area-based method generally showed more than 3-fold higher bark mass loss than the density-based method (even higher if considering bark cover loss), and volume-corrected wood mass losses were 1.08–1.12 times higher than density-based mass loss. The deviation of bark mass loss between the two methods was higher for tree species with thicker inner bark. Bark generally decomposed twice as fast as wood across species, and faster decaying bark came with faster decaying wood (R2 = 0.26, p = 0.006). We strongly suggest using corrected volume when assessing wood mass loss especially for the species with faster decomposable sapwood and all the wood at advanced decay stages. Further studies of coarse stem decomposition should consider trait ‘afterlife’ effects of inner bark and estimate fraction of stem bark cover to obtain more accurate decay rates. Our new method should benefit our understanding of the in situ dynamics of woody debris decay and monitoring research in different forest ecosystems world-wide, and should aid meta-analyses across diverse studies.

    Compound in basil, fennel and aniseed harms DNA
    Yang, Shuo - \ 2020
    UVA radiation promotes tomato growth through morphological adaptation leading to increased light interception
    Zhang, Yating ; Kaiser, Elias ; Zhang, Yuqi ; Zou, Jie ; Bian, Zhonghua ; Yang, Qichang ; Li, Tao - \ 2020
    Environmental and Experimental Botany 176 (2020). - ISSN 0098-8472
    Blue light - Leaf photosynthesis - Phenolics - Photomorphogenesis - Red light syndrome - UVA radiation

    UVA radiation (315−400 nm) is the main component of solar UV radiation. Although it shares photoreceptors (i.e. cryptochromes and phototropins) with blue light (400−500 nm), its function in plant biology is unclear to a large extent. This study aimed at exploring how UVA radiation affects plant morphology and physiology, and at distinguishing to what extent these effects differ from those of blue light. Tomato plants were grown under monochromatic red (R), dichromatic red and blue (R/B = 7:1), as well as red and two different levels of UVA radiation (R/UVA = 7:1 and 15:1, respectively), with identical photon flux density (250 μmol⋅m−2⋅s−1). Peak intensities of UVA, B and R were 370, 450 and 660 nm, respectively. We showed that replacing blue by UVA (in a background of red light) induced plant morphological modifications, as reflected by larger leaf area, steeper leaf angles, flatter leaves and longer stems. UVA had reduced effects on leaf secondary metabolism compared to blue light, resulting in significantly lower total phenolics and flavonoid contents, as well as concentrations of UV-absorbing compounds. In addition, UVA had a similar function as blue light in shaping the development of the photosynthetic apparatus, as both wavebands alleviated the ‘red light syndrome’ (i.e. low photosynthetic capacity, reduced photosynthetic electron transport, and unresponsive stomata). We conclude that: 1) UVA promotes tomato growth through morphological adaptation leading to increased light interception; 2) UVA affects leaf secondary metabolite accumulation less strongly than blue light; 3) UVA functions similarly to blue light in maintaining leaf photosynthetic functioning. Thus, unlike previously suggested, UVA cannot be unequivocally considered as an abiotic stress factor. This research adds to the understanding of plant processes in response to UVA radiation and provides a basis for future recipes for growing plants with artificial light.

    Effects of nitrogen addition on soil methane uptake in global forest biomes
    Xia, Nan ; Du, Enzai ; Wu, Xinhui ; Tang, Yang ; Wang, Yang ; Vries, Wim de - \ 2020
    Environmental Pollution 264 (2020). - ISSN 0269-7491
    Forest - Nitrogen addition - Nitrogen deposition - Soil methane uptake

    Nitrogen (N) deposition has been conventionally thought to decrease forest soil methane (CH4) uptake, while the biome specific and dose dependent effect is poorly understood. Based on a meta-analysis of 63 N addition trials from 7 boreal forests, 8 temperate forests, 13 subtropical and 4 tropical forests, we evaluated the effects of N addition on soil CH4 uptake fluxes across global forest biomes. When combining all N addition levels, soil CH4 uptake was insignificantly decreased by 7% in boreal forests, while N addition significantly decreased soil CH4 uptake by 39% in temperate forests and by 21% in subtropical and tropical forests, respectively. Meta-regression analyses, however, indicated a shift from a positive to a negative effect on soil CH4 uptake with increasing N additions both in boreal forests (threshold = 48 kg N ha−1 yr−1) and temperate forests (threshold = 27 kg N ha−1 yr−1), while no such shift was found in subtropical and tropical forests. Considering that current N deposition to most boreal and temperate forests is below the abovementioned thresholds, N deposition likely exerts a positive to neutral effect on soil CH4 uptake in both forest biomes. Our results provide new insights on the biome specific and dose dependent effect of N addition on soil CH4 sink in global forests and suggest that the current understanding that N deposition decreases forest soil CH4 uptake is flawed by high levels of experimental N addition.

    Optimum strip width increases dry matter, nutrient accumulation, and seed yield of intercrops under the relay intercropping system
    Raza, Muhammad Ali ; Feng, Ling Yang ; Werf, Wopke van der; Iqbal, Nasir ; Khan, Imran ; Khan, Ahsin ; Din, Atta Mohi Ud ; Naeem, Muhammd ; Meraj, Tehseen Ahmad ; Hassan, Muhammad Jawad ; Khan, Aaqil ; Lu, Feng Zhi ; Liu, Xin ; Ahmed, Mukhtar ; Yang, Feng ; Yang, Wenyu - \ 2020
    Food and Energy Security 9 (2020)2. - ISSN 2048-3694
    competition ratio - growing space - maize - relay intercropping - soybean

    Strip width management is a critical factor for producing higher crop yields in relay intercropping systems. A 2-year field experiment was carried out during 2012 and 2013 to evaluate the effects of different strip width treatments on dry-matter production, major-nutrient (nitrogen, phosphorus, and potassium) uptake, and competition parameters of soybean and maize in relay intercropping system. The strip width (SW) treatments were 0.40, 0.40, and 0.40 m (SW1); 0.40, 0.40, and 0.50 m (SW2); 0.40, 0.40, and 0.60 m (SW3); and 0.40, 0.40, and 0.70 m (SW4) for soybean row spacing, maize row spacing, and spacing between soybean and maize rows, respectively. As compared to sole maize (SM) and sole soybean (SS), relay-intercropped maize and soybean accumulated lower quantities of nitrogen, phosphorus, and potassium in all treatments. However, maize in SW1 accumulated higher nitrogen, phosphorus, and potassium than SW4 (9%, 9%, and 8% for nitrogen, phosphorus, and potassium, respectively). Soybean in SW3 accumulated 25% higher nitrogen, 33% higher phosphorus, and 24% higher potassium than in SW1. The improved nutrient accumulation in SW3 significantly increased the soybean dry matter by 19%, but slightly decreased the maize dry matter by 6% compared to SW1. Similarly, SW3 increased the competition ratio value of soybean (by 151%), but it reduced the competition ratio value of maize (by 171%) compared to SW1. On average, in SW3, relay-cropped soybean produced 84% of SS seed yield and maize produced 98% of SM seed yield and achieved the land equivalent ratio of 1.8, demonstrating the highest level in the world. Overall, these results suggested that by selecting the appropriate strip width (SW3; 0.40 m for soybean row spacing, 0.40 m maize row spacing, and 0.60 m spacing between soybean and maize rows), we can increase the nutrient uptake (especially nitrogen, phosphorus, and potassium), dry-matter accumulation, and seed yields of relay-intercrop species under relay intercropping systems.

    Effect of CMC degree of substitution and gliadin/CMC ratio on surface rheology and foaming behavior of gliadin/CMC nanoparticles
    Peng, Dengfeng ; Jin, Weiping ; Arts, Miriam ; Yang, Jack ; Li, Bin ; Sagis, Leonard M.C. - \ 2020
    Food Hydrocolloids 107 (2020). - ISSN 0268-005X
    Degree of substitution - Foam - Nanoparticle - Ratio - Structure - Surface behavior

    To understand the influence of the degree of substitution (DS) of sodium carboxymethyl cellulose (CMC) and gliadin:CMC ratio on the surface and foaming behaviors of gliadin-CMC nanoparticles (G-CMC NPs) at pH 3, three DS (0.7–1.2) and four ratios (G:CMC~1:0.5–1:2) were investigated. Gliadin NPs with a pH of 3 were utilized as a control. Results showed that G-CMC NPs at all investigated DS and ratios possessed higher foamability and foam stability when compared to the control. This indicated that adding CMC to gliadin NP suspensions could greatly improve their foaming properties. G-CMC NPs with a DS of 0.7 and 0.9, had lower surface charge than G-CMC1.2 NPs, resulting in a weaker electrostatic repulsion, thus leading to faster adsorption kinetics and higher foamability. By increasing the G:CMC ratio from 1:0.5 to 1:2, the particle size gradually rose, and the zeta potential remained unchanged. At a ratio of 1:2, the highest foam stability was observed. This might be ascribed to the high continuous phase viscosity at this ratio, which could slow down the drainage rate and protect the bubbles against coalescence and disproportionation. It was worth mentioning that G-CMC NPs at all ratios exhibited impressive foamability (~220%) even at a very low concentration of G-CMC NPs (gliadin was fixed at 1 mg/mL). This implies that G-CMC NPs could act as a new efficient foaming agent, and based on its simple preparation, have the potential to be widely applied in foamed food.

    Assessing the impacts of recent-past climatic constraints on potential wheat yield and adaptation options under Mediterranean climate in southern Portugal
    Yang, Chenyao ; Fraga, Helder ; Ieperen, Wim van; Santos, João A. - \ 2020
    Agricultural Systems 182 (2020). - ISSN 0308-521X
    Adaptation strategy - Regional crop modelling - STICS - Terminal abiotic stress - Winter wheat - Yield gap

    Wheat yield potentials under rainfed Mediterranean conditions have been long limited by late-in-season occurrence of enhanced water deficits and high temperatures, coinciding with sensitive reproductive stages. Present study aims to quantify and separate the impacts of two main abiotic stresses (drought & heat) on potentially attainable wheat yields, in a typical Mediterranean environment of southern Portugal (Alentejo) over 1986—2015. We also evaluate how possible adaptation options could mitigate potential yield losses (reduce the gap between actual and potential yield). Previously calibrated STICS soil-crop model is used for these purposes, which has been satisfactorily evaluated herein for yield simulations using additional field data before running at regional level. By coupling with high-resolution gridded soil and climate datasets, STICS simulations reliably reproduce the inter-annual variability of 30-year regional yield statistics, together with reasonable estimations of experimental potential yields. Therefore, the model is useful to explore the source of yield gap in the region. The quantified impacts, though with some uncertainties, identify the prolonged terminal drought stress as the major cause of yield gap, causing 40–70% mean potential yield losses. In contrast, a short-duration of crop heat stress (≥38 °C) during late grain-filling phase only results in small-to-moderate reductions (up to 20%). Supplemental Irrigation (SI) during reproductive stages provides good adaptive gains to recover potential yield losses by 15–30%, while the proposed early-flowering cultivar is more useful in escaping the terminal heat stress (5–15% adaptive gains) than avoiding prolonged drought stress. In addition, advancing sowing date generally favours wheat production with a robust spatial-temporal pattern. Therefore, combined options based on application of SI, using balanced early-flowering cultivar and early sowing date, may contribute to considerably reduce local yield gap, where current yields can account for 60% of potential yields (26–32% without adaptation). Regional impact assessment and adaptation modelling studies are essential to support agricultural policy development under climate change and variability. The recommended combined adaptation may also represent a promising adaptation strategy for rainfed wheat cropping system in other regions with similar Mediterranean conditions. However, the existing spatial-temporal variability of adaptation response highlights the need to address adaptation strategies at a more detailed local scale with better flexible design.

    Border-row proportion determines strength of interspecific interactions and crop yields in maize/peanut strip intercropping
    Wang, Ruonan ; Sun, Zhanxiang ; Zhang, Lizhen ; Yang, Ning ; Feng, Liangshan ; Bai, Wei ; Zhang, Dongsheng ; Wang, Qi ; Evers, Jochem B. ; Liu, Yang ; Ren, Jianhong ; Zhang, Yue ; Werf, Wopke van der - \ 2020
    Field Crops Research 253 (2020). - ISSN 0378-4290
    border-row effect - relative yield total - row configuration - strip cropping - yield components

    Strip intercropping enables increases in yields and ecological services in agriculture. Crop yields of species grown in strip intercropping are often related to the yield responses (increases or decreases) in the outer rows of the strips: the border rows. This suggests that the yield response can be modulated by changing the proportion of border rows in the field. Here we studied the relationship between component species yields and proportion of border rows in strip intercrops of maize (Zea mays L.) and peanut (Arachis hypogaea Linn.). We tested four different intercrops with equal proportions of maize and peanut but a different number of rows per strip: M2P2 (2 rows maize intercropped with 2 rows peanut), M4P4, M6P6, M8P8, and sole maize (SM) and sole peanut (SP). The border-row proportions were 1, 0.5, 0.33 and 0.25 for the intercropping M2P2 to M8P8, respectively, and 0 for the pure stands. Yield responded positively to the proportion of border rows for maize, but negatively for peanut, confirming the dominance of maize in this system. Kernel number per ear of maize and pod number per plant of peanut were the main yield components that responded to the border-row proportion. Across three years, relative maize yield (yield in intercropping divided by yield in monoculture), varied from 0.76 in M2P2 to 0.56 in M8P8, while relative peanut yield varied from 0.19 in M2P2 to 0.39 in M8P8. Relative yield total was not significantly different from one in any of the mixtures. Yield of intercropped maize in border rows was 48% higher than in inner rows and the sole crop, in part due to a significantly higher kernel number per ear (13%). Yield of intercropped peanut in border rows was on average 29% lower than in inner rows and 48% lower than in sole peanut. Yield responses in border rows were independent from the border-row proportion. The results show that relative crop yields responded strongly to variation in border-row proportion resulting from variation in strip width from 1 to 4 m. Strip width thus provides a mechanism to control the strength of interspecific plant interactions and relative yields in strip intercropping.

    Dynamic balancing of intestinal short-chain fatty acids: the crucial role of bacterial metabolism
    Xu, Youqiang ; Zhu, Yang ; Li, Xiuting ; Sun, Baoguo - \ 2020
    Trends in Food Science and Technology 100 (2020). - ISSN 0924-2244 - p. 118 - 130.
    Background: Short-chain fatty acids (SCFAs) play important physiological roles in human health. Adverse effects on health are known with a low or excessive concentration of SCFAs although the optimal level of SCFAs in the body is unknown yet. The level of endogenous SCFAs is affected by many factors of which gut bacteria are the most important one. However, how gut bacteria and a dietary intervention affect SCFA balance in the gut still needs to be clarified.
    Scope and approach: In addition to addressing the importance of a dynamic balance of SCFAs for health, we discuss the factors affecting the dynamic balance of SCFAs, especially the gut SCFA-producing bacteria, including the classification of the bacteria, their response to diet, the SCFAs metabolic pathways and the catalytic mechanisms of the main rate-limiting enzymes.
    Key findings and conclusions: SCFAs levels can be regulated endogenously and exogenously. Exogenous regulation delivers SCFAs to gut by esterification with dietary fibres. Endogenous regulation like diet, directly or indirectly affect gut microbiota, including their abundance, fitness and SCFAs production. Until now, 74 bacterial species are reported to produce SCFAs, the metabolic pathways are classified into 4 categories, and the 4 rate-limiting enzymes in the metabolic pathways are summarized. We also propose methods for long-lasting endogenous SCFAs balancing, including identifying the minimum sets of SCFA-producing bacterial group, and possible dietary intervention to form a minimum group of gut microbiota for SCFAs synthesis. An integrated approach will help realize the rational regulation of balanced SCFAs levels to benefit human health.
    Valuation of Wetland Ecosystem Services in National Nature Reserves in China’s Coastal Zones
    Li, Xiaowei ; Yu, Xiubo ; Hou, Xiyong ; Liu, Yubin ; Li, Hui ; Zhou, Yangming ; Xia, Shaoxia ; Liu, Yu ; Duan, Houlang ; Wang, Yuyu ; Dou, Yuehan ; Yang, Meng ; Zhang, Li - \ 2020
    Sustainability 12 (2020)8. - ISSN 2071-1050
    Wetlands provide ecosystem services for regional development, and, thus, have considerable economic value. In this study, a combination of evaluation methods was carried out to evaluate the wetland ecosystem services provided by national nature reserves in 11 coastal provinces/municipalities in China. We constructed a literature database containing 808observations (over 170 papers) on field-scale research for wetlands in China’s coastal zones. Using this literature database, as well as land use (LU) data, net primary productivity (NPP), and statistical data, and digital elevation model (DEM) data, we established a valuation framework and database for nine important ecosystem services of the 13 wetland types in the study area. After the large-scale academic literature review, the ordinary kriging offered by Geostatistical Analyst tools was used to interpolate the physical dimensions of the unmeasured locations. The results showed that: 1) the wetland ecosystem services in 35 national nature reserves have a total value of 33.168billion USD/year; 2) the values of wetland ecosystem services revealed considerable spatial variability along China’s coastal zones; and 3) assessments provide additional insights into the trade-offs between different ecosystem services and wetland types. The valuation framework and database established in this study can contribute to the mapping of wetland ecosystem services in coastal zones.
    Modeling of industrial-scale anaerobic solid-state fermentation for Chinese liquor production
    Jin, Guangyuan ; Uhl, Philipp ; Zhu, Yang ; Wijffels, René H. ; Xu, Yan ; Rinzema, Arjen - \ 2020
    Chemical Engineering Journal 394 (2020). - ISSN 1385-8947
    Chinese liquor - Heat transfer - Mathematical modeling - Product inhibition - Solid-state fermentation - Temperature modeling

    Traditional solid-state fermentation processes can give fluctuating product quality and quantity due to difficulties in control and scale up. This paper describes an engineering study of an industrial-scale anaerobic solid-state fermentation process for Chinese liquor (Baijiu) production, aimed at better understanding of the traditional process, as an initial step for future optimization. This mixed-culture fermentation is done in 0.44-m3 vessels embedded in the soil. At this scale, the fermentation is limited by product inhibition. We developed mathematical models based on the Han-Levenspiel equation for product inhibition, with parameters derived from measured data. The models accurately predicted the concentrations of starch and dry matter. A model with radial conduction into a small soil volume around the fermenter and consecutive vertical conduction into the underlying soil accurately predicted the pit temperature in the heating and cooling phases. This model is very sensitive to the values used for the enthalpies of combustion, meaning that direct measurement of the heat production rate would be preferable. In the industry practice, the fermenter volume can be from around 0.20 to 15.00 m3. The model predicts that overheating will occur not only in larger fermenters, but also in the 0.44-m3 fermenters when the soil temperature is high in summer. Our model predictions are consistent with observed behavior in the industry. Our findings can be used to improve this traditional process, as well as similar systems.

    A global database of soil nematode abundance and functional group composition
    Hoogen, Johan van den; Geisen, Stefan ; Wall, Diana H. ; Wardle, David A. ; Traunspurger, Walter ; Goede, Ron G.M. de; Adams, Byron J. ; Ahmad, Wasim ; Ferris, Howard ; Bardgett, Richard D. ; Bonkowski, Michael ; Campos-Herrera, Raquel ; Cares, Juvenil E. ; Caruso, Tancredi ; Brito Caixeta, Larissa de; Chen, Xiaoyun ; Costa, Sofia R. ; Creamer, Rachel ; Cunha e Castro, José Mauro da; Dam, Marie ; Djigal, Djibril ; Escuer, Miguel ; Griffiths, Bryan S. ; Gutiérrez, Carmen ; Hohberg, Karin ; Kalinkina, Daria ; Kardol, Paul ; Kergunteuil, Alan ; Korthals, Gerard ; Krashevska, Valentyna ; Kudrin, Alexey A. ; Li, Qi ; Liang, Wenju ; Magilton, Matthew ; Marais, Mariette ; Martín, José Antonio Rodríguez ; Matveeva, Elizaveta ; Mayad, El Hassan ; Mzough, E. ; Mulder, Christian ; Mullin, Peter ; Neilson, Roy ; Nguyen, Duong T.A. ; Nielsen, Uffe N. ; Okada, Hiroaki ; Rius, Juan Emilio Palomares ; Pan, Kaiwen ; Peneva, Vlada ; Pellissier, Loïc ; Silva, Julio Carlos Pereira da; Pitteloud, Camille ; Powers, Thomas O. ; Powers, Kirsten ; Quist, Casper W. ; Rasmann, Sergio ; Moreno, Sara Sánchez ; Scheu, Stefan ; Setälä, Heikki ; Sushchuk, Anna ; Tiunov, Alexei V. ; Trap, Jean ; Vestergård, Mette ; Villenave, Cecile ; Waeyenberge, Lieven ; Wilschut, Rutger A. ; Wright, Daniel G. ; Keith, Aidan M. ; Yang, Jiuein ; Schmidt, Olaf ; Bouharroud, R. ; Ferji, Z. ; Putten, Wim H. van der; Routh, Devin ; Crowther, Thomas W. - \ 2020
    Scientific Data 7 (2020)1. - ISSN 2052-4463

    As the most abundant animals on earth, nematodes are a dominant component of the soil community. They play critical roles in regulating biogeochemical cycles and vegetation dynamics within and across landscapes and are an indicator of soil biological activity. Here, we present a comprehensive global dataset of soil nematode abundance and functional group composition. This dataset includes 6,825 georeferenced soil samples from all continents and biomes. For geospatial mapping purposes these samples are aggregated into 1,933 unique 1-km pixels, each of which is linked to 73 global environmental covariate data layers. Altogether, this dataset can help to gain insight into the spatial distribution patterns of soil nematode abundance and community composition, and the environmental drivers shaping these patterns.

    Partial purification and characterization of a broad-spectrum bacteriocin produced by a Lactobacillus plantarum zrx03 isolated from infant's feces
    Lei, Shuang ; Zhao, Ruixiang ; Sun, Junliang ; Ran, Junjian ; Ruan, Xiaoli ; Zhu, Yang - \ 2020
    Food Science and Nutrition 8 (2020)5. - ISSN 2048-7177 - p. 2214 - 2222.
    antimicrobial stability - bacteriocin - Lactobacillus plantarum zrx03 - purification

    Lactobacillus plantarum zrx03 was a bacteriocin-producing strain isolated from infant's feces. The fermentation supernatant produced by this strain could strongly inhibit Escherichia coli JM109 ATCC 67387, Staphylococcus aureus ATCC 25923, and Listeria monocytogenes CICC 21633, in which the diameter of inhibition zone was 12.83 ± 0.62 mm, 15.08 ± 0.31 mm, 6.75 ± 0.20 mm, respectively, compared with lactic acid bacteria N1, N2, M13, M21, M31, and M37. According to amplification of 16S rRNA gene and identification of phylogenetic tree, this strain had a 1,450 bp sequence and 100% identity to the L. plantarum strain. Based on the influence of different protease treatments, such as pepsin, trypsin, papain, and proteinase K on the antimicrobial activity, this antimicrobial substance was considered to be a natural protein. Using bacteriocin produced by this strain as study object of this experiment, it had been extracted from ammonium sulfate precipitation and different organic solvents. The results showed that ethyl acetate was selected as the optimal solution to crude extraction of bacteriocin after comparing ammonium sulfate precipitation method and organic solvent extraction method, such as n-butanol, n-hexane, dichloromethane, trichloromethane, in which the diameter of the inhibition zones was above 28 mm. Results also showed the inhibition spectrum of the obtained bacteriocin had a broad spectrum of inhibition which could inhibit Gram-positive, Gram-negative, yeast. Especially, it could effectively inhibit S. aureus ATCC 25923, Bacillus subtilis CICC 10002, Bacillus anthracis CICC 20443, E. coli JM109 ATCC 67387, and Salmonella CMCC 541, and the zone diameter of inhibition has reached more than 28 mm. Moreover, it had a good thermal stability which antibacterial activity was retained 70.58% after treatment at 121°C for 30 min, and pH-stability was between pH 2.0–9.0. These results suggested bacteriocin produced by L. plantarum zrx03 had potential application prospects in food preservation.

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