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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Plastic film cover during the fallow season preceding sowing increases yield and water use efficiency of rain-fed spring maize in a semi-arid climate
Zhang, Zhe ; Zhang, Yanqing ; Sun, Zhanxiang ; Zheng, Jiaming ; Liu, Enke ; Feng, Liangshan ; Feng, Chen ; Si, Pengfei ; Bai, Wei ; Cai, Qian ; Yang, Ning ; Werf, Wopke van der; Zhang, Lizhen - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 203 - 210.
Film cover - Soil temperature - Water availability - Yield components

Plastic film mulch increases crop yields in rain-fed agriculture in cool semi-arid climates by warming the soil and reducing evaporative water losses. The semi-arid Khorchin area in Northeast China is an important production area for rain-fed maize. Drought stress occurs frequently, even if plastic film mulch is applied at sowing. We hypothesized that the yield and water capture of maize could be increased by reducing evaporative loss of water by use of plastic film cover during the autumn and winter preceding sowing. In this study, we compared maize growth, water uptake and yield in three film cover treatments: (1) film cover from the autumn before maize sowing until maize harvest (autumn mulching: AM), (2) film cover from maize sowing till harvest (conventional practice) (spring mulching: SM), (3) no film cover (no mulch: NM). Field experiments were conducted in Fuxin city, Khorchin region, Liaoning province, China in 2013/2014 and 2014/2015. Autumn mulching increased grain yield on average by 18% when compared to spring mulching and by 36% when compared to no mulching. The 1000-kernel weight in AM was 7% higher than in SM, and 12% higher than in NM. Soil water content in the root zone before sowing was 35 mm greater in AM than in SM and NM. Water uptake during the growing season was 34 mm greater in AM than in SM and NM. Water use efficiency for grain yield (yield per unit water uptake) in AM was on average 2.5% higher than in conventional mulching (SM) and 27% higher than in NM. Autumn mulching advanced development, with an advance of 5 days in tasseling time as compared to SM and 10 days when compared to NM. These results show that film cover during the fallow period before maize sowing can increase crop yield and water use efficiency, and reduce climate risks in rain-fed agriculture under semi-arid conditions.

Cross-fertilizing weed science and plant invasion science to improve efficient management: A European challenge
Müller-Schärer, H. ; Sun, Y. ; Chauvel, B. ; Karrer, G. ; Kazinczi, G. ; Kudsk, P. ; Oude Lansink, A.G.J.M. ; Schaffner, U. ; Skjoth, C.A. ; Smith, M. ; Vurro, M. ; Weger, L.A. De; Lommen, S.T.E. - \ 2018
Basic and Applied Ecology (2018). - ISSN 1439-1791 - 13 p.
Both weed science and plant invasion science deal with noxious plants. Yet, they have historically developed as two distinct
research areas in Europe, with different target species, approaches and management aims, as well as with diverging institutions
and researchers involved. We argue that the strengths of these two disciplines can be highly complementary in implementing
management strategies and outline how synergies were created in an international, multidisciplinary project to develop efficient
and sustainable management of common ragweed, Ambrosia artemisiifolia. Because this species has severe impacts on human
health and is also a crop weed in large parts of Europe, common ragweed is one of the economically most important plant
invaders in Europe. Our multidisciplinary approach combining expertise from weed science and plant invasion science allowed
us (i) to develop a comprehensive plant demographic model to evaluate and compare management tools, such as optimal cutting
regimes and biological control for different regions and habitat types, and (ii) to assess benefits and risks of biological control.
It further (iii) showed ways to reconcile different stakeholder interests and management objectives (health versus crop yield),
and (iv) led to an economic model to assess invader impact across actors and domains, and effectiveness of control measures.
(v) It also led to design and implement management strategies in collaboration with the various stakeholder groups affected by
noxious weeds, created training opportunities for early stage researchers in the sustainable management of noxious plants, and
actively promoted improved decision making regarding the use of exotic biocontrol agents at the national and European level.
We critically discuss our achievements and limitations, and list and discuss other potential Old World (Afro-Eurasian) target
Reduced phloem uptake of Myzus persicae on an aphid resistant pepper accession
Sun, Mengjing ; Voorrips, Roeland E. ; Steenhuis-Broers, Greet ; van't Westende, Wendy ; Vosman, Ben - \ 2018
BMC Plant Biology 18 (2018)1. - ISSN 1471-2229
Aphid resistance screening - Callose - Capsicum baccatum - EPG - Real-time PCR

Background: The green peach aphid (GPA), Myzus persicae, is economically one of the most threatening pests in pepper cultivation, which not only causes direct damage but also transmits many viruses. Breeding aphid resistant pepper varieties is a promising and environmentally friendly method to control aphid populations in the field and in the greenhouse. Until now, no strong sources of resistance against the GPA have been identified. Therefore the main aims of this study were to identify pepper materials with a good level of resistance to GPA and to elucidate possible resistance mechanisms. Results: We screened 74 pepper accessions from different geographical areas for resistance to M. persicae. After four rounds of evaluation we identified one Capsicum baccatum accession (PB2013071) as highly resistant to M. persicae, while the accessions PB2013062 and PB2012022 showed intermediate resistance. The resistance of PB2013071 resulted in a severely reduced uptake of phloem compared to the susceptible accession, as determined by Electrical Penetration Graph (EPG) studies. Feeding of M. persicae induced the expression of callose synthase genes and resulted in callose deposition in the sieve elements in resistant, but not in susceptible plants. Conclusions: Three aphid resistant pepper accessions were identified, which will be important for breeding aphid resistant pepper varieties in the future. The most resistant accession PB2013071 showed phloem-based resistance against aphid infestation.

Effect of ambient temperature fluctuation on the timing of the transition to the generative stage in cauliflower
Sun, Xiaoxue ; Bucher, Johan ; Ji, Yongran ; Dijk, Aalt D.J. Van; Immink, Richard G.H. ; Bonnema, Guusje - \ 2018
Environmental and Experimental Botany (2018). - ISSN 0098-8472 - 9 p.
Cauliflower (Brassica oleracea ssp. botrytis) is an important vegetable that is grown worldwide from the tropics to temperate zones. The harvested product is the curd, which consists of arrested inflorescence meristems. The switch from vegetative development to curd formation in cauliflower, referred to as the generative switch, is strongly temperature responsive in the majority of varieties. We aimed at measuring the delay in timing of the generative switch by high ambient temperature, and how temperature affects the expression of genes with a potential role in timing of this switch. A seven day increase of six degrees in day and night temperature during vegetative development, results in a substantial delay of the generative switch and increased variation in timing of this switch in sensitive cultivars only. The expression level of the Cauliflower FRUITFULL-like gene BoFULc increased significantly at the generative switch and therefore can be used as marker for this developmental phase change. The expression profiles of the majority of the other investigated cauliflower flowering time genes resembled the expression behaviour of their homologous genes in the model plant Arabidopsis thaliana during the vegetative stage and flowering induction. An exception was the expression of two FLC paralogues BoFLC-1 and BoFLC-3, which showed opposite expression profiles of which the pattern of BoFLC-1 resembles the pattern expected based on Arabidopsis FLC. This interesting observation suggests different roles for these two FLC paralogs in regulation of the timing of the generative switch in cauliflower. Unexpectedly, high temperatures did not delay timing of expression of the majority of investigated genes in meristems and leaves of sensitive cultivars that were delayed in the switch to the generative stage. However, expression of a few potential flowering-time genes was affected by the high temperature treatment in a sensitive cultivar, making them potential candidates to be causal for the observed delay in generative switch.
Use of the beta growth function to quantitatively characterize the effects of plant density and a growth regulator on growth and biomass partitioning in cotton
Mao, Lili ; Zhang, Lizhen ; Sun, Xuezhen ; Werf, Wopke van der; Evers, Jochem B. ; Zhao, Xinhua ; Zhang, Siping ; Song, Xianliang ; Li, Zhaohu - \ 2018
Field Crops Research 224 (2018). - ISSN 0378-4290 - p. 28 - 36.
Beta growth function - Biomass partitioning - Growth rate - Mepiquat chloride - Plant population density
Allocation of newly formed biomass towards plant organs is a key determinant of plant performance that is affected by agronomic practices such as plant population density and use of growth regulators. Here we quantified biomass allocation of intercropped cotton (Gossypium hirsutum) growing at two population densities (3.0 and 7.5 plants m−2) and with or without application of the growth regulator mepiquat chloride (MC) in three consecutive years. The beta growth function was used to quantitatively characterize the dynamics of biomass partitioning. Compared to low density, high density increased daily growth rate and final above-ground dry matter, but decreased allocation to fruits. Application of MC did not affect dry matter accumulation but increased allocation to fruits by 22%. The parameters of the beta growth function have a clear biological interpretation, providing a useful quantitative characterization of the effect of management on dry matter allocation in cotton. The function may also be used to model organ-specific daily assimilate partitioning as a component in models of plant growth and crop production with the consideration of discussed caveats.
An experimental approach in revisiting the magnetic orientation of cattle
Weijers, Debby ; Hemerik, Lia ; Heitkönig, Ignas M.A. - \ 2018
PLoS One 13 (2018)4. - ISSN 1932-6203
In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations–excluding the hottest part of the day–of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals.
An experimental approach in revisiting the magnetic orientation of cattle
Hemerik, A. ; Heitkönig, I.M.A. - \ 2018
In response to the increasing number of observational studies on an apparent south-north orientation in non-homing, non-migrating terrestrial mammals, we experimentally tested the alignment hypothesis using strong neodymium magnets on the resting orientation of individual cattle in Portugal. Contrary to the hypothesis, the 34 cows in the experiment showed no directional preference, neither with, nor without a strong neodymium magnet fixed to their collar. The concurrently performed 2,428 daytime observations - excluding the hottest part of the day - of 659 resting individual cattle did not show a south-north alignment when at rest either. The preferred compass orientation of these cows was on average 130 degrees from the magnetic north (i.e., south east). Cow compass orientation correlated significantly with sun direction, but not with wind direction. In as far as we can determine, this is the first experimental test on magnetic orientation in larger, non-homing, non-migrating mammals. These experimental and observational findings do not support previously published suggestions on the magnetic south-north alignment in these mammals.
Performance of an environmentally benign acid base flow battery at high energy density
Egmond, W.J. van; Saakes, M. ; Noor, I. ; Porada, S. ; Buisman, C.J.N. ; Hamelers, H.V.M. - \ 2018
International Journal of Energy Research 42 (2018)4. - ISSN 0363-907X - p. 1524 - 1535.
acid base flow battery - bipolar membrane - co-ion transport - energy efficiency - ion exchange membranes - renewable energy storage - sustainable materials
An increasing fraction of energy is generated by intermittent sources such as wind and sun. A straightforward solution to keep the electricity grid reliable is the connection of large-scale electricity storage to this grid. Current battery storage technologies, while providing promising energy and power densities, suffer from a large environmental footprint, safety issues, and technological challenges. In this paper, the acid base flow battery is re-established as an environmental friendly means of storing electricity using electrolyte consisting of NaCl salt. To achieve a high specific energy, we have performed charge and discharge cycles over the entire pH range (0–14) at several current densities. We demonstrate stable performance at high energy density (2.9 Wh L−1). Main energy dissipation occurs by unwanted proton and hydroxyl ion transport and leads to low coulombic efficiencies (13%–27%).
Arbuscular mycorrhizal fungi negatively affect nitrogen acquisition and grain yield of maize in a N deficient soil
Wang, Xin Xin ; Wang, Xiaojing ; Sun, Yu ; Cheng, Yang ; Liu, Shitong ; Chen, Xinping ; Feng, Gu ; Kuyper, Thomas W. - \ 2018
Frontiers in Microbiology 9 (2018)MAR. - ISSN 1664-302X
Arbuscular mycorrhizal fungi - Benomyl - Competition - Maize - Nitrogen uptake
Arbuscular mycorrhizal fungi (AMF) play a crucial role in enhancing the acquisition of immobile nutrients, particularly phosphorus. However, because nitrogen (N) is more mobile in the soil solution and easier to access by plants roots, the role of AMF in enhancing N acquisition is regarded as less important for host plants. Because AMF have a substantial N demand, competition for N between AMF and plants particularly under low N condition is possible. Thus, it is necessary to know whether or not AMF affect N uptake of plants and thereby affect plant growth under field conditions. We conducted a 2-year field trial and pot experiments in a greenhouse by using benomyl to suppress colonization of maize roots by indigenous AMF at both low and high N application rates. Benomyl reduced mycorrhizal colonization of maize plants in all experiments. Benomyl-treated maize had a higher shoot N concentration and content and produced more grain under field conditions. Greenhouse pot experiments showed that benomyl also enhanced maize growth and N concentration and N content when the soil was not sterilized, but had no effect on maize biomass and N content when the soil was sterilized but a microbial wash added, providing evidence that increased plant performance is at least partly caused by direct effects of benomyl on AMF. We conclude that AMF can reduce N acquisition and thereby reduce grain yield of maize in N-limiting soils.
Habitat heterogeneity promotes intraspecific trait variability of shrub species in Australian granite inselbergs
Smedt, P. de; Ottaviani, G. ; Wardell-Johnson, G. ; Sýkora, K.V. ; Mucina, L. - \ 2018
Folia Geobotanica 53 (2018)2. - ISSN 1211-9520 - p. 133 - 145.
Fire-refugia - Functional traits - Global biodiversity hotspot - Mediterranean-type climate - Plant resource strategies - Proteaceae
The role of intraspecific trait variability is increasingly recognized as a key factor shaping plant fitness and community assembly worldwide. Studying the direct effects of habitat heterogeneity on trait expression of individual plants of the same species is a useful tool to quantify intraspecific trait variability locally. We investigated how habitat heterogeneity on granite inselbergs affected intraspecific trait variability of 19 functional traits in three shrub species of the family Proteaceae in south western Australia, a global biodiversity hotspot. We used pairwise comparison (single trait) and multivariate analysis (multiple traits, functional space) to detect shifts in trait patterns. Consistent with our predictions, we found that individuals developing in putatively more stressful habitats (highly sun-irradiated, shallow-soil patches on the outcrops) were characterized by trait expressions indicative of more conservative resource-related strategies when compared with plants occurring in the surrounding woodlands that were experiencing more benign ecological conditions. These results were significant for two out of three species. Granite inselbergs promoted plant longevity, a signal that these granite inselbergs might offer refugial conditions defined as protection against fire.
Short-term salt stress strongly affects dynamic photosynthesis, but not steady-state photosynthesis, in tomato (Solanum lycopersicum)
Zhang, Yuqi ; Kaiser, Elias ; Zhang, Yating ; Yang, Qichang ; Li, Tao - \ 2018
Environmental and Experimental Botany 149 (2018). - ISSN 0098-8472 - p. 109 - 119.
Dynamic photosynthesis - Fluctuating light - Salt stress - Solanum lycopersicum - Stomatal conductance - Tomato
Salt stress occurs worldwide due to widespread soil salinization. Also, plants are often subjected to rapidly alternating periods of sun and shade (sunflecks). Despite this combined occurrence of salt stress and sunflecks, dynamic photosynthetic responses to sunflecks under salt stress remain unknown. This study addresses this discrepancy by exploring photosynthetic gas exchange and chlorophyll fluorescence, both after dark-light transitions and during artificial light fluctuations (lightflecks and shadeflecks), in salt stressed leaves. Three weeks old growth-chamber grown tomato (Solanum lycopersicum Mill ‘Beijing Cherry Tomato’) plants were exposed to 0, 70 or 140 mM of sodium chloride (NaCl), for 7–9 days. Photosynthetic induction after dark-light transitions was strongly inhibited in salt-stressed leaves, due to increased transient stomatal limitation and slower apparent Rubisco activation. During photosynthetic induction, non-photochemical quenching (NPQ) and intrinsic water use efficiency (WUEi) were positively correlated with [NaCl]. Under periods of low light (shadeflecks), the longer the shadefleck lasted, the more strongly photosynthesis after re-illumination was downregulated by salt stress, and this downregulation in photosynthesis was positively correlated with the severity of salt stress. Under regularly applied lightflecks, salt stress decreased photosynthesis by 12–42%, which was mainly caused by decreased stomatal conductance. Salt-stressed leaves also displayed significantly lower stomatal pore area and stomatal index. Crucially, salt stress did not affect steady-state photosynthetic capacity as indicated by similar light and CO2 response curves of photosynthesis. We conclude that a short-term salt stress strongly affects dynamic leaf photosynthesis in tomato while its effect on steady state photosynthesis is negligible.
Influence of calcium and phosphate on pH dependency of arsenite and arsenate adsorption to goethite
Deng, Yingxuan ; Li, Yongtao ; Li, Xiaojing ; Sun, Yang ; Ma, Jie ; Lei, Mei ; Weng, Liping - \ 2018
Chemosphere 199 (2018). - ISSN 0045-6535 - p. 617 - 624.
Adsorption - Arsenic - CD-MUSIC - Modeling - Multi-component
In the environment, simultaneous presence of arsenic (As) of different oxidation states is common, which hampers our understanding of As behavior. In the current study, the pH dependency of arsenite (As(III)) and arsenate (As(V)) adsorption to goethite under the influence of calcium (Ca2+) (as a major cation) and phosphate (PO4 3−) (as a major anion) was studied, and the reliability of the CD-MUSIC model prediction was tested. The results show that the presence of the major ions led in general to a weaker and more complicated pH dependency of As adsorption. Calcium promoted As(V) adsorption especially at high pH, which can reverse the direction of the pH dependency. The presence of Ca2+ can even decrease As(III) adsorption when As(V) and/or PO4 3− are present. Phosphate competed strongly with both As(III) and As(V) in their adsorption, especially at intermediate and low pH. In the multi-component system, As(III) adsorbs weaker than As(V) over the environmental relevant pH range, therefore it is often the dominant As species in solution and soluble As(III) concentration generally decreases with increasing pH. In the same pH range, As(V) adsorption shows a complicated pH dependency. Soluble As(V) reaches a minimum around pH 6 at high concentration of major bivalent cations (e.g. Ca2+), whereas soluble As(V) will decrease with pH at low bivalent cation concentrations. The experimental results can be reliably predicted and explained with the CD-MUSIC model. The outcome of this study can provide understanding needed in the risk assessment and remediation of As contaminated soils and water.
Agroforestry enables high efficiency of light capture, photosynthesis and dry matter production in a semi-arid climate
Zhang, Dongsheng ; Du, Guijuan ; Sun, Zhanxiang ; Bai, Wei ; Wang, Qi ; Feng, Liangshan ; Zheng, Jiaming ; Zhang, Zhe ; Liu, Yang ; Yang, Shu ; Yang, Ning ; Feng, Chen ; Cai, Qian ; Evers, Jochem B. ; Werf, Wopke van der; Zhang, Lizhen - \ 2018
European Journal of Agronomy 94 (2018). - ISSN 1161-0301 - p. 1 - 11.
Border row effect - Leaf photosynthesis - Millet - Peanut - Sweet potato
Agroforestry systems, which combine annual crops with trees, are used widely in semi-arid regions to reduce wind erosion and improve resource (e.g. water) use efficiency. Limited knowledge is available on optimizing such systems by the choice of crop species with specific physiological traits (i.e. C3 vs C4, N-fixing vs non-N-fixing). In this study we quantified the light interception and utilization efficiency of trees and crops in agroforestry systems comprising apricot trees and a C3 species (sweet potato), a C4 species (millet) or an N-fixing legume species (peanut), and used measurements in the sole stands as a reference. A significant delay in leaf growth was found in millet. Maximum LAI of millet was 17% higher in agroforestry then expected from sole crop LAI, taking into account the relative density of 2/3, while a 25% decrease in maximum LAI compared to expected was observed in peanut and sweet potato. The total light interception in agroforestry was 54% higher than in sole tree stands and 23% higher than in sole crops. The millet intercepted more light and produced more biomass in agroforestry than peanut and sweet potato. The LUE values of the crops in the mixed systems were higher than those of the sole crops, as was the photosynthetic efficiency of individual leaves, especially in plants in the border rows of the crop strips. High light capture in agroforestry made a greater contribution to productivity of understory crops than the increases in light use efficiency. We conclude that agroforestry systems with apricot trees and annual crops, especially millet, can improve light utilization in semi-arid climates and contribute to regional sustainability and adaptation to climate change.
Plasticity of lifelong calorie-restricted C57BL/6J mice in adapting to a medium-fat diet intervention at old age
Rusli, F. ; Boekschoten, M.V. ; Borelli, Vincenzo ; Sun, Chen ; Lute, C. ; Menke, Aswin L. ; Heuvel, Joost van den; Salvioli, Stefano ; Franceschi, Claudio ; Müller, Michael ; Steegenga, W.T. - \ 2018
Mus musculus - GSE102593 - PRJNA398117
Plasticity of lifelong calorie-restricted C57BL/6J mice in adapting to a medium-fat diet intervention at old age
Rusli, Fenni ; Boekschoten, Mark V. ; Borelli, Vincenzo ; Sun, Chen ; Lute, Carolien ; Menke, Aswin L. ; Heuvel, Joost van den; Salvioli, Stefano ; Franceschi, Claudio ; Müller, Michael ; Steegenga, Wilma T. - \ 2018
Aging Cell 17 (2018)2. - ISSN 1474-9718
NAFLD - Aging - DNA methylation - Glycomics - Liver - Long-term CR - Transcriptomics
Calorie restriction (CR) is a dietary regimen that supports healthy aging. In this study, we investigated the systemic and liver-specific responses caused by a diet switch to a medium-fat (MF) diet in 24-month-old lifelong, CR-exposed mice. This study aimed to increase the knowledge base on dietary alterations of gerontological relevance. Nine-week-old C57BL/6J mice were exposed either to a control, CR, or MF diet. At the age of 24 months, a subset of mice of the CR group was transferred to ad libitumMF feeding (CR-MF). The mice were sacrificed at the age of 28 months, and then, biochemical and molecular analyses were performed. Our results showed that, despite the long-term exposure to the CR regimen, mice in the CR-MF group displayed hyperphagia, rapid weight gain, and hepatic steatosis. However, no hepatic fibrosis/injury or alteration in CR-improved survival was observed in the diet switch group. The liver transcriptomic profile of CR-MF mice largely shifted to a profile similar to the MF-fed animals but leaving ~22% of the 1,578 differentially regulated genes between the CR and MF diet groups comparable with the expression of the lifelong CR group. Therefore, although the diet switch was performed at an old age, the CR-MF-exposed mice showed plasticity in coping with the challenge of a MF diet without developing severe liver pathologies.
Analysis of coffee (Coffea arabica L.) performance in relation to radiation levels and rates of nitrogen supply I. Vegetative growth, production and distribution of biomass and radiation use efficiency
Bote, Adugna Debela ; Ayalew, Biruk ; Ocho, Fikre L. ; Anten, Niels P.R. ; Vos, Jan - \ 2018
European Journal of Agronomy 92 (2018). - ISSN 1161-0301 - p. 115 - 122.
Light extinction - Orthotropic stem - Plagiotropic branch - Radiation interception - Shade avoidance

Intensively managed full-sun coffee (Coffea arabica L.), is potentially highly productive, but has shown disappointingly low yield performance, as adequate resource supplies (especially plant nutrition) are needed to sustain the productivity. In order to underpin rational radiation and nutrient management, the current study focussed on growth and development of 2.5 years old trees in relation to nitrogen supply in combination with several degrees of radiation. Three coffee varieties were grown under four levels of radiation (30–100% full sun) and four rates of nitrogen supply (0–88 g tree−1 y−1), arranged in a randomized split-split plot design at Jimma University horticultural farm, Ethiopia, and their biomass increment (growth) and allocation, and crown characteristics were measured. Growth responded positively to both radiation and nitrogen supply, with positive interactions for several plant attributes (including number and length of branches, numbers of pairs of leaves per branch, radiation use efficiency). Plant height and area per leaflet declined with higher radiation level, while the positive effect of larger N supply on these attributes declined with increase in radiation. Branch length and leaf dry weight showed the most positive plasticity in response to higher radiation. Specific leaf area declined from 187 in shade (reducing sunlight to 30%) to 109 cm2 g−1 in full sun without effect of N. Positive effects of nitrogen on growth and biomass production were mediated through higher radiation-use efficiency, RUE, ranging from 0.23 to 0.46 g MJ−1 (PAR). Variables associated with dry matter partitioning were modestly responsive to either N or radiation. All these responses were consistent across the three varieties. The study enhanced the understanding of vegetative growth and biomass production of coffee trees and explored traits that underlie these patterns. The study also yielded essential information for managing shade and nitrogen supply in both open sun and agroforestry systems and yielded basic information for developing coffee growth models

Analysis of coffee (Coffea arabica L.) performance in relation to radiation level and rate of nitrogen supply II. Uptake and distribution of nitrogen, leaf photosynthesis and first bean yields
Bote, Adugna Debela ; Zana, Zewdneh ; Ocho, Fikre L. ; Vos, Jan - \ 2018
European Journal of Agronomy 92 (2018). - ISSN 1161-0301 - p. 107 - 114.
Apparent nitrogen recovery - Biomass - N uptake - Partitioning - Physiological efficiency - Radiation
Natural supply of nitrogen is often limiting coffee production. From the viewpoints of growth and biomass production, adequate nitrogen supply is important. Growing coffee under full sunlight not only enhances potential yields but also increases demands for nitrogen fertilizer, the extent of which is ill quantified. This paper provides a comprehensive analysis of N uptake and distribution, biomass production, photosynthetic characteristics of 2.5 years old trees and first bean yields of 3.5 years old coffee trees in response to four radiation treatments (30%–100% of full sun), factorially combined with four rates of nitrogen supply (0–88 g tree−1 y−1). The experiment was arranged in a randomized split-split plot design and was conducted at Jimma University horticultural farm, Ethiopia, using three coffee varieties. With larger N application and higher level of radiation, more N was utilized and more biomass and yield were produced. The fertilizer-N recovery ranged from 7 to 17% and declined with larger N supply and increased with radiation level. Coffee trees provided with larger amount of N had higher amounts of N per unit leaf area, light-saturated rate of leaf photosynthesis and first bean yield compared to trees grown in low N supply and limited radiation. The relation between biomass and plant N content was conservative across coffee varieties and can be used to estimate N content from biomass or calculate required uptake to produce a given amount of biomass. Though testing of the relation for other climatic conditions is advisable, this relation can also be used in the development of process-based quantitative coffee tree growth models,. Achieving synchronies between N supply and coffee trees demand without excess or deficiency requires further investigation of options to improve the low nitrogen recovery.
Brassica rapa hairy root extracts promote skin depigmentation by modulating melanin production and distribution
Sena, Luigi Michele ; Zappelli, Claudia ; Apone, Fabio ; Barbulova, Ani ; Tito, Annalisa ; Leone, Antonella ; Oliviero, Teresa ; Ferracane, Rosalia ; Fogliano, Vincenzo ; Colucci, Gabriella - \ 2018
Journal of Cosmetic Dermatology 17 (2018)2. - ISSN 1473-2130 - p. 246 - 257.
Active ingredient - Cell biology - Depigmentation - Gene expression - Hairy root cultures - Melanogenesis

Background: Skin whitening products, used for ages by Asian people for cultural and esthetic purposes, are very popular nowadays in Western countries as well, where the need to inhibit skin spots after sun exposure has become not only a cosmetic but also a health-related issue. Thus, the development of effective and safe depigmenting agents derived from natural products gets continuous attention by cosmetic brands and consumers. Objectives: The aim of this study was to determine the effects of two preparations, obtained from the hairy root cultures of the species Brassica rapa, on melanogenesis and the expression of the extracellular matrix proteins involved in a correct pigment distribution. Methods: The two preparations, obtained by water-ethanol extraction and by digestion of cell-wall glycoproteins of the root cells, were chemically characterized and tested on skin cell cultures and on human skin explants to investigate on their dermatological activities. Results: Both the extracts were able to decrease melanin synthesis pathway in melanocytes and modulate the expression of genes involved in melanin distribution. One of the extracts was also effective in inducing the expression of laminin-5 and collagen IV, involved into the maintenance of tissue integrity. The two extracts, when tested together on human skin explants, demonstrated a good synergic hypopigmenting activity. Conclusions: Taken together, the results indicate that the extracts from B. rapa root cultures can be employed as cosmetic active ingredients in skin whitening products and as potential therapeutic agents for treating pigmentation disorders.

Effects of food-borne nanomaterials on gastrointestinal tissues and microbiota
Bouwmeester, Hans ; Zande, Meike van der; Jepson, Mark A. - \ 2018
Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology 10 (2018)1. - ISSN 1939-5116 - 12 p.

Ingestion of engineered nanomaterials is inevitable due to their addition to food and prevalence in food packaging and domestic products such as toothpaste and sun cream. In the absence of robust dosimetry and particokinetic data, it is currently challenging to accurately assess the potential toxicity of food-borne nanomaterials. Herein, we review current understanding of gastrointestinal uptake mechanisms, consider some data on the potential for toxicity of the most commonly encountered classes of food-borne nanomaterials (including TiO2 , SiO2 , ZnO, and Ag nanoparticles), and discuss the potential impact of the luminal environment on nanoparticle properties and toxicity. Much of our current understanding of gastrointestinal nanotoxicology is derived from increasingly sophisticated epithelial models that augment in vivo studies. In addition to considering the direct effects of food-borne nanomaterials on gastrointestinal tissues, including the potential role of chronic nanoparticle exposure in development of inflammatory diseases, we also discuss the potential for food-borne nanomaterials to disturb the normal balance of microbiota within the gastrointestinal tract. The latter possibility warrants close attention given the increasing awareness of the critical role of microbiota in human health and the known impact of some food-borne nanomaterials on bacterial viability. For further resources related to this article, please visit the WIREs website.

Severe hypovitaminosis D in active tuberculosis patients and its predictors
Wang, Qiuzhen ; Liu, Yufeng ; Ma, Yan ; Han, Lei ; Dou, Mei ; Zou, Yue ; Sun, Limei ; Tian, Hong ; Li, Tongxia ; Jiang, Guofeng ; Du, Baoli ; Kou, Tingyan ; Song, Jiaqi ; Kok, Frans J. ; Schouten, Evert G. - \ 2018
Clinical Nutrition 37 (2018)3. - ISSN 0261-5614 - p. 1034 - 1040.
Diabetes - Fish consumption - Outdoor activity - Serum 25(OH)D - Severe vitamin D deficiency - Tuberculosis

Background & aims: Tuberculosis (TB) patients have a significant vitamin D deficiency (VDD) endemic, which may be closely related to the onset and progress of the disease. The comorbidity of diabetes (DM) and TB has posed an increasing challenge in recent years. However, the influence of DM on TB and the possible mechanism are still uncertain. We carried out this study to identify the nutritional status of vitamin D (VD) in TB patients in a northern city in China (latitude 36° N) and investigate the possible predictors of severe vitamin D deficiency (SVDD). Methods: A cross-sectional study including 461 active TB patients (192 with and 269 without DM) were randomly selected from Qingdao Chest Hospital from June 2015 to August 2016. We measured serum 25 hydroxyvitamin D [25(OH)D], and investigated the association between sociodemographic, dietary intake, DM, body mass index (BMI), severity of initial TB signs and symptoms (TB score) and VD status. Multivariate logistic regression analysis was used to define the possible predictors of SVDD. Results: The median serum 25(OH)D concentration was 8.50 ng/mL. Of the 461 TB patients included, 383 (83.1%) had VDD [25(OH)D < 20 ng/mL], and 217 (47.1%) had SVDD [25(OH)D < 8 ng/mL]. The variables associated with serum 25(OH)D concentrations were DM, outdoor activity level, TB score and BMI (p < 0.05). Patients with severe TB score had nearly 5 fold higher risk of having SVDD compared with those in mild subgroup [OR (95% CI) = 4.919 (2.644-9.150), p < 0.001]. Low outdoor activity level also increased the odds of SVDD, while DM and high fish consumption showed protect effects. Conclusions: Severe hypovitaminosis D is prevalent in active TB patients, and the main predictors of SVDD were severe TB score, low outdoor activity, inadequate fish consumption. Lowered serum 25(OH)D may be associated with increased risk of TB in DM.

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