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Striga hermonthica MAX2 restores branching but not the Very Low Fluence Response in the Arabidopsis thaliana max2 mutant
Liu, Q. ; Zhang, Y. ; Matusovaa, R. ; Charnikhova, T. ; Amini, M. ; Jamil, M. ; Fernandez-Aparicio, M. ; Huang, K. ; Timko, M.P. ; Westwood, J.H. ; Ruyter-Spira, C.P. ; Krol, A.R. van der; Bouwmeester, H.J. - \ 2014
New Phytologist 202 (2014)2. - ISSN 0028-646X - p. 531 - 541.
arabidopsis seed-germination - box protein max2 - plant hormone - strigolactone - inhibition - photomorphogenesis - stimulants - karrikins - molecule - pathway
Seed germination of Striga spp. (witchweeds), one of the world’s most destructive parasitic weeds, cannot be induced by light but is specifically induced by strigolactones. It is not known whether Striga uses the same components for strigolactone signaling as host plants, whether it has endogenous strigolactone biosynthesis and whether there is post-germination strigolactone signaling in Striga. Strigolactones could not be detected in in vitro grown Striga, while for host-grown Striga, the strigolactone profile is dominated by a subset of the strigolactones present in the host. Branching of in vitro grown Striga is affected by strigolactone biosynthesis inhibitors. ShMAX2, the Striga ortholog of Arabidopsis MORE AXILLARY BRANCHING 2 (AtMAX2) – which mediates strigolactone signaling – complements several of the Arabidopsis max2-1 phenotypes, including the root and shoot phenotype, the High Irradiance Response and the response to strigolactones. Seed germination of max2-1 complemented with ShMAX2 showed no complementation of the Very Low Fluence Response phenotype of max2-1. Results provide indirect evidence for ShMAX2 functions in Striga. A putative role of ShMAX2 in strigolactone-dependent seed germination of Striga is discussed.
Preventive doping control screening analysis of prohibited substances in human urine using rapid-resolution liquid chromatography/high-resolution time-of-flight mass spectrometry
Vonaparti, A. ; Lyris, E. ; Angelis, Y.S. ; Panderi, I. ; Koupparis, M. ; Tsantili- Kakoulidou, A. ; Peters, R.J.B. ; Nielen, M.W.F. ; Georgakopoulos, C.G. - \ 2010
Rapid Communications in Mass Spectrometry 24 (2010)11. - ISSN 0951-4198 - p. 1595 - 1609.
solid-phase extraction - anabolic-steroids - metabolite identification - high-throughput - olympic games - drugs - stimulants - ionization - validation - diuretics
Unification of the screening protocols for a wide range of doping agents has become an important issue for doping control laboratories. This study presents the development and validation of a generic liquid chromatography/time-of-flight mass spectrometry (LC/TOFMS) screening method of 241 small molecule analytes from various categories of prohibited substances (stimulants, narcotics, diuretics, ß2-agonists, ß-blockers, hormone antagonists and modulators, glucocorticosteroids and anabolic agents). It is based on a single-step liquid-liquid extraction of hydrolyzed urine and the use of a rapid-resolution liquid chromatography/high-resolution time-of-flight mass spectrometric system acquiring continuous full scan data. Electrospray ionization in the positive mode was used. Validation parameters consisted of identification capability, limit of detection, specificity, ion suppression, extraction recovery, repeatability and mass accuracy. Detection criteria were established on the basis of retention time reproducibility and mass accuracy. The suitability of the methodology for doping control was demonstrated with positive urine samples. The preventive role of the method was proved by the case where full scan acquisition with accurate mass measurement allowed the retrospective reprocessing of acquired data from past doping control samples for the detection of a designer drug, the stimulant 4-methyl-2-hexanamine, which resulted in re-reporting a number of stored samples as positives for this particular substance, when, initially, they had been reported as negatives.
Generic sample preparation combined with high-resolution liquid chromatography- time-of-flight mass spectrometry for unification of urine screening in doping-control laboratories
Peters, R.J.B. ; Oosterink, J.E. ; Stolker, A.A.M. ; Georgakopoulos, C.G. ; Nielen, M.W.F. - \ 2010
Analytical and Bioanalytical Chemistry 396 (2010)7. - ISSN 1618-2642 - p. 2583 - 2598.
solid-phase extraction - veterinary drugs - high-throughput - masking agents - uplc-tof - diuretics - stimulants - glucocorticosteroids - beta(2)-agonists - corticosteroids
A unification of doping-control screening procedures of prohibited small molecule substances—including stimulants, narcotics, steroids, ß2-agonists and diuretics—is highly urgent in order to free resources for new classes such as banned proteins. Conceptually this may be achieved by the use of a combination of one gas chromatography–time-of-flight mass spectrometry method and one liquid chromatography–time-of-flight mass spectrometry method. In this work a quantitative screening method using high-resolution liquid chromatography in combination with accurate-mass time-of-flight mass spectrometry was developed and validated for determination of glucocorticosteroids, ß2-agonists, thiazide diuretics, and narcotics and stimulants in urine. To enable the simultaneous isolation of all the compounds of interest and the necessary purification of the resulting extracts, a generic extraction and hydrolysis procedure was combined with a solid-phase extraction modified for these groups of compounds. All 56 compounds are determined using positive electrospray ionisation with the exception of the thiazide diuretics for which the best sensitivity was obtained by using negative electrospray ionisation. The results show that, with the exception of clenhexyl, procaterol, and reproterol, all compounds can be detected below the respective minimum required performance level and the results for linearity, repeatability, within-lab reproducibility, and accuracy show that the method can be used for quantitative screening. If qualitative screening is sufficient the instrumental analysis may be limited to positive ionisation, because all analytes including the thiazides can be detected at the respective minimum required levels in the positive mode. The results show that the application of accurate-mass time-of-flight mass spectrometry in combination with generic extraction and purification procedures is suitable for unification and expansion of the window of screening methods of doping laboratories. Moreover, the full-scan accurate-mass data sets obtained still allow retrospective examination for emerging doping agents, without re-analyzing the samples.
A simple staining method for observation of germinated Striga seeds
Shusheng Long, ; Lendzemo, V.W. ; Kuyper, T.W. ; Zhengsheng Kang, ; Vierheilig, H. ; Steinkellner, S. - \ 2008
Seed Science Research 18 (2008)2. - ISSN 0960-2585 - p. 125 - 129.
In vitro techniques are essential for Striga research and the development of appropriate control methods. In the laboratory, pre-screening of non-host or false-host plants of Striga for trap cropping or the screening of hosts for resistance involves visual evaluation of Striga seed germination that may be stimulated by plant parts or root exudates. This technique is presently laborious because the small Striga radicles are colourless. A number of solutions were evaluated to visualize the radicles of Striga hermonthica to obtain a reliable, simple and fast staining method yielding good contrast for visual observation, with readily available, inexpensive and minimally toxic dyes and staining solutions. The inks Brilliant Blue (Pelikan), Blue (Geha) and Brilliant Green (Pelikan), in either vinegar or lactic acid, produced radicles with excellent contrast, whereas radicles stained with Brilliant Red (Pelikan), Black (Sheaffer), Brilliant Black (Pelikan) gave good contrast. Striga radicles stained with Aniline Blue in vinegar or lactic acid, or Coomassie Brilliant Blue R250 in lactic acid, showed excellent contrast. Radicles stained with Ink Black (Sheaffer), Cotton Brown, or Rubin S in either vinegar or lactic acid also showed good contrast. With water as the diluent, only Lactophenol Blue showed excellent contrast. For health, safety and environmental concerns, availability and staining time, Blue ink in household vinegar (5% acetic acid) appears to be an excellent dye for Striga radicles and could be used in routine Striga germination assays
Long-Acting Methylphenidate-OROS in Youths with Attention-Deficit Hyperactivity Disorder Suboptimally Controlled with Immediate-Release Methylphenidate. A study of cost effectiveness in The Netherlands.
Faber, A. ; Agthoven, M. van; Kalverdijk, L.J. ; Tobi, H. ; Jong-van den Berg, L.T.W. de; Annemans, L. ; Postma, M.J. - \ 2008
CNS Drugs 22 (2008)2. - ISSN 1172-7047 - p. 157 - 170.
once-a-day - deficit/hyperactivity-disorder - children - stimulants - care - adolescents - population - outcomes - trial
BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is the most common mental health disorder in youths. Stimulants are the drugs of first choice in the treatment of ADHD. It has been suggested that full costs associated with the treatment of ADHD may be reduced by once-daily administration regimens of stimulants. OBJECTIVES: To estimate the cost effectiveness of treatment with long-acting methylphenidate osmotic release oral system (OROS) [Concerta((R))] for youths with ADHD for whom treatment with immediate-release (IR) methylphenidate is suboptimal. STUDY DESIGN: We developed a Markov model to obtain an incremental cost-effectiveness ratio (ICER). The analysis covered 10 years, with a Markov cycle of 1 day. Costs (in 2005 euros [euro]) included medication, consultations and treatment interventions, and additional costs for attending special education. Quality-adjusted life-years (QALYs) were used as the effectiveness measure. Outcome probabilities were taken from the medical literature and an expert panel of five child psychiatrists and paediatricians. Univariate sensitivity analyses were performed to assess the robustness of the base-case estimate. Multivariate sensitivity analysis was used to estimate a worst- and best-case ICER. RESULTS: The ICER of methylphenidate-OROS treatment in youths with ADHD for whom treatment with IR methylphenidate is suboptimal was euro2004 per QALY. Total costs after 10 years were euro15 739 for the IR methylphenidate pathway and euro16 015 for the methylphenidate-OROS pathway. In the univariate sensitivity analysis, the ICER was sensitive to changes in resource use and the probability of stopping stimulant treatment in favour of IR methylphenidate. An ICER of 0 was reached with a 6.2% price reduction of methylphenidate-OROS. CONCLUSION: Methylphenidate-OROS is a cost-effective treatment for youths with ADHD for whom treatment with IR methylphenidate is suboptimal. Higher medication costs of methylphenidate-OROS were compensated for by savings on resource use, yielding similar 10-year costs compared with treatment with IR methylphenidate. Our analysis is sensitive to both clinical parameters and (differences in) resource utilization and costs between the groups modelled, warranting further research within clinical trials and observational databases, and into the full scope of costs.
Alternatieve aanwending van (incidentele) reststromen buiten de diervoedersector
Bouwmeester, H. ; Bokma-Bakker, M.H. ; Bondt, N. ; Roest, J.G. van der - \ 2006
Wageningen : RIKILT (Rapport / RIKILT 2006.008) - 60
voedselafval - stimulerende middelen - dranken - afvalhergebruik - voer - diervoedering - biomassa - energie - technologie - kennis - food wastes - stimulants - beverages - waste utilization - feeds - animal feeding - biomass - energy - technology - knowledge
Flavonoids from cabbage are feeding stimulants for diamondback moth larvae additional to glucosinolates : chemoreception and behaviour
Loon, J.J.A. van; Wang, C.Z. ; Nielsen, J.K. ; Gols, R. ; Qiu, Y.T. - \ 2002
Entomologia Experimentalis et Applicata 104 (2002). - ISSN 0013-8703 - p. 27 - 34.
brassica oleracea - flavonoïden - waardplanten - plutella xylostella - stimulerende middelen - flavonoids - host plants - stimulants
In caterpillars two styloconic contact chemoreceptors on the maxillary galea are assumed to contain the main taste receptors involved in host plant selection. The diamondback moth, Plutella xylostella L. is a specialist feeder of plants in the Brassicaceae, a plant family characterized by the biosynthesis of glucosinolates. We used pea (Pisum sativum L., Leguminosae) as a neutral non-host for a dual-choice leaf disc assay to quantify feeding stimulation by glucosinolates and flavonoids. Increasing concentrations of sinigrin resulted in significant preferences for sinigrin-treated leaf discs, with a threshold between 1 and 3 μM. Millimolar concentrations of four of the five flavonol triglucosides likewise elicited a significant preference for flavonoid-treated leaf discs. A mixture of four flavonoids and sinigrin was significantly preferred over sinigrin-treated leaf discs alone. Vigorous unicellular electrophysiological responses of medial maxillary styloconic taste sensilla were observed in response to five glucosinolates (glucocapparin, sinigrin, glucobrassicin, glucoiberin, and gluconasturtiin). This medial taste neuron responded in a dose-dependent manner to a concentration series of sinigrin, with a threshold of response of ca. 1 μM. The lateral sensillum styloconicum contained a neuron sensitive to sucrose, glucose, and fructose. However, no responses in the two types of maxillary styloconic sensilla to the phagostimulatory flavonoids could be detected, suggesting that other taste organs mediate chemoreception of flavonoids. We conclude that diamondback moth larvae employ a combination of biosynthetically distinct categories of feeding stimulants which allows for a higher degree of discriminatory ability than when this would be based on glucosinolates alone.
|Vitamine- en mineralensuppletie voor ouderen.
Staveren, W.A. van - \ 1996
Voeding 57 (1996)6. - ISSN 0042-7926 - p. 11 - 12.
consumenteninformatie - consumenten - vraag - ouderen - voedsel - voedseladditieven - voedingsmiddelen - anorganische verbindingen - menopauze - mineralen - onderzoek - zouten - specerijen - stimulerende middelen - sporenelementen - vitaminen - consumer information - consumers - demand - elderly - food - food additives - foods - inorganic compounds - menopause - minerals - research - salts - spices - stimulants - trace elements - vitamins
|Bladgroenten als vitamine-A bron niet effectief.
Pee, S. de - \ 1996
Voeding 57 (1996)12. - ISSN 0042-7926 - p. 18 - 20.
carotenen - carotenoïden - consumptiepatronen - voedsel - voedselhygiëne - voedingsmiddelen - indonesië - lactatie - bladgroenten - voedingstoestand - provitaminen - retinol - specerijen - stimulerende middelen - zogen - vitaminen - carotenes - carotenoids - consumption patterns - food - food hygiene - foods - indonesia - lactation - leafy vegetables - nutritional state - provitamins - spices - stimulants - suckling - vitamins
Gegevens van onderzoek naar de rol van voedsel bij het terugdringen van vitamine A-tekort bij zogende vrouwen
Koffie en coronaire hartziekten: cholesterol-verhogende factor uit koffiebonen.
Urgert, R. ; Katan, M.B. - \ 1996
Voeding 57 (1996)9. - ISSN 0042-7926 - p. 21 - 23.
cholesterol - koffie - hartziekten - lipiden - voeding - stimulerende middelen - coffee - heart diseases - lipids - nutrition - stimulants
Food-based approaches for controlling vitamin A deficiency : studies in breastfeeding women in Indonesia
Pee, S. de - \ 1996
Agricultural University. Promotor(en): J.G.A.J. Hautvast; C.E. West; Muhalil. - S.l. : De Pee - ISBN 9789054855576 - 192
voedsel - voedingsmiddelen - vitaminen - specerijen - stimulerende middelen - retinol - voedingsstoornissen - zogende vrouwen - vrouwen - zwangerschap - indonesië - food - foods - vitamins - spices - stimulants - nutritional disorders - lactating women - women - pregnancy - indonesia
<br/>Micronutrient deficiencies seriously hinder mental and physical development and are still an important cause of death in developing countries. Therefore, goals have been set worldwide for the year 2000: to eliminate deficiencies of vitamin A and iodine and to reduce prevalence of iron deficiency anemia in women by onethird of 1990 levels. Food-based approaches for the control of micronutrient deficiencies, using foods naturally rich in micronutrients and/or fortified foods, are preferable, because a pharmaceutical approach can only reach a selective group and is less sustainable. This thesis describes research on the role of foods for improving vitamin A status of breastfeeding women in Indonesia.<p>In developing countries, people derive 80-85% of vitamin A from plant sources in the form of provitamin A carotenoids, which the body converts to vitamin A. Preformed vitamin A, retinol, exists only in animal foods and accounts for 15-20% of vitamin A intake. Our questionnaire confirmed that dark-green leafy vegetables are the most important source of vitamin A. However, feeding a portion of dark-green leafy vegetables daily for 12 weeks did not improve vitamin A status, while it improved after feeding a wafer enriched with the same amount of β-carotene. This, as well as results from other carefully controlled studies, contradicts the assumption that vegetables rich in provitamin A carotenoids can play an important role in the control of vitamin A deficiency. Causes of poor bioavailability of vegetable carotenoids could include: complex matrix of leaves; absorption inhibitors, such as fibre which entraps carotenoids, or other carotenoids which may compete for absorption; parasitic infestation; and genetic and/or dietary factors.<p>A very limited effect on vitamin A status should not lead to the conclusion that promoting the consumption of dark-green leafy vegetables is no longer necessary, but food approaches should be based on a variety of foods. Also, factors to calculate vitamin A activity of carotenoids should be reconsidered. In addition, we conclude that vitamin A intake questionnaires, which could be very simple, should only be used to estimate the risk of poor vitamin A status at community level. Vitamin A status and changes in status are best assessed by measuring serum retinol. The measurement of serum β-carotene is recommended for evaluating food-based interventions, because it is very responsive.
Vitamin intake and status in elderly Europeans
Wielen, R.P.J. van der - \ 1995
Agricultural University. Promotor(en): W.A. van Staveren; J.G.A.J. Hautvast; Lisette de Groot. - S.l. : Van der Wielen - ISBN 9789054854180 - 167
voedsel - voedingsmiddelen - vitaminen - specerijen - stimulerende middelen - ouderen - ouderdom - europa - food - foods - vitamins - spices - stimulants - elderly - old age - europe
De simultane bepaling van vitamine B1 en vitamine B2 in voedingsmiddelen met behulp van HPLC
Slangen, J.H. ; Struijs-van de Putte, H.M. van der; Kleijnen, H.C.H. ; Hollman, P.C.H. - \ 1990
Wageningen : RIKILT (Rapport / RIKILT 90.15) - 36
voedingsmiddelen - chemische samenstelling - voedsel - vitaminen - specerijen - stimulerende middelen - nicotinamide - vitamine b complex - riboflavine - pantoteenzuur - choline - myo-inositol - vloeistofchromatografie - hplc - foods - chemical composition - food - vitamins - spices - stimulants - vitamin b complex - riboflavin - pantothenic acid - liquid chromatography
Dit rapport geeft een overzicht van de totstandkoming van een simultane analysemethode voor thiaminechloride en riboflavine in voedingsmiddelen.
Medicinal and poisonous plants of the tropics : proceedings of symposium 5-35 of the 14th International Botanical Congress, Berlin 24 July-1 August 1987
Leeuwenberg, A.J.M. - \ 1987
Wageningen : Pudoc - ISBN 9789022009215 - 152
geneesmiddelen - medicinale planten - fytotoxinen - giftige planten - stimulerende middelen - subtropen - toxische stoffen - tropen - wilde planten - plantkunde - natuurlijke producten - economische botanie - drugs - medicinal plants - phytotoxins - poisonous plants - stimulants - subtropics - toxic substances - tropics - wild plants - botany - natural products - economic botany
|Transport and metabolism of Indole - 3 - acetic acid in Coleus petiole segments of increasing agr
Veen, H. ; Jacobs, W.P. - \ 1969
Wageningen : [s.n.] (Publication / Plant physiological research centre no. 85) - 6
lamiaceae - iaa - absorptie - emissie - omloop - hormonen - plantengroeiregulatoren - stimulerende middelen - opwekkende planten - plantenontwikkeling - absorption - emission - circulation - hormones - plant growth regulators - stimulants - stimulant plants - plant development
|Effects of auxins and cytokinins on the growth of discs of parenchymous tissues
Bruinsma, J. - \ 1967
Wageningen : [s.n.] (Publication / Centre for plant physiological research no. 54) - 3
groei - hormonen - plantenontwikkeling - plantengroeiregulatoren - opwekkende planten - stimulerende middelen - growth - hormones - plant development - plant growth regulators - stimulant plants - stimulants
|Auxin transport in explants of Coleus
Gorter, C.J. ; Veen, H. - \ 1966
Wageningen : [s.n.] (Publication / Plant physiological research centre, Wageningen no. 45) - 4
groei - hormonen - sierplanten - plantenontwikkeling - opwekkende planten - stimulerende middelen - coleus - growth - hormones - ornamental plants - plant development - stimulant plants - stimulants
An attempt to analysis of the effect of light on stem elongation and flowering in Hyoscyamus niger L.
Lint, P.J.A.L. de - \ 1960
Wageningen University. Promotor(en): E.C. Wassink. - Wageningen : Veenman - 59
groei - plantenontwikkeling - stimulerende middelen - opwekkende planten - growth - plant development - stimulants - stimulant plants
The shooting of Hyoscyamus niger was studied as a reaction to radiation with coloured or white light in various combinations of intensity and duration. Research into the reaction to very short photoperiods became possible by continuing treatments with weak light not longer than 6 or 10 days, and then to keep the plants in LD of white light until shooting.The data presented were interpreted as follows. Hyoscyamus would grow vegetatively if floral induction (an accumulative and autonomous process comprising flower bud initiation and a shooting impulse) were inhibited, also if stem elongation underlay formative inhibition (suppression of etiolation). Thus, vegetative growth may be due either to unsuitable photoperiod, primarily inhibiting floral induction, or to unsuitable light quality, primarily causing formative inhibition of stem elongation.The formative inhibition was due to the production of an inhibitor precursor, which became active principally in darkness, after a light period. In the dark, the precursor would be gradually converted into an inhibitor which itself had no measurable persistence but took immediate effect as an inhibition. In longer maintained darkness the plant was no longer inhibited, no more than during light. The inhibition by short photoperiods increased with time of radiation as in a formative light action. Near-infrared may be assumed to antagonize inhibition by inactivating the precursor.
The effect of flowering on adventitious root-formation
Selim, H.H.A. - \ 1956
Wageningen University. Promotor(en): S.J. Wellensiek. - Wageningen : Veenman - 38
plantenfysiologie - plantenontwikkeling - bloemen - bloei - wortels - stimulerende middelen - opwekkende planten - plantenvermeerdering - stekken - plant physiology - plant development - flowers - flowering - roots - stimulants - stimulant plants - propagation - cuttings
The rooting of cuttings from day-neutral tomato was not influenced by flower development, nor by SD or LD treatments of them or of the mother plants. In cuttings of the SD plant Perilla crispa flower initiation and development severely inhibited rooting. Leaves produced about 61 % of the roots, buds about 16 %, stems a small proportion. Together these organs were more effective than their summed separate effects. A supposed substance regulating adventitious root formation would need more than 2 days for transport from the leaves or buds. The physiological age of the cutting markedly affected rooting. The presence of buds during SD treatment may have changed auxin distribution, which became concentrated in the apical region and slightly promoted rooting there. Stems could induce flowering. Day length had no influence during rooting. Light on the base of the cutting inhibited root formation. In the LD plant red clover, flower initiation inhibited rooting of cuttings.In both SD and LD plants, auxin distribution during flower initiation and development must cause antagonism between adventitious root formation and flowering. This did not apply to day-neutral plants with a vegetative terminal bud, but perhaps to those with a terminal flower bud.
Factoren die de variatie van het vitamine C in de plant bepalen
Mathot, H.J. - \ 1945
Wageningen University. Promotor(en): A.M. Sprenger. - Wageningen : Veenman - 176
plantensamenstelling - ascorbinezuur - voedsel - voedingsmiddelen - vitaminen - specerijen - stimulerende middelen - plant composition - ascorbic acid - food - foods - vitamins - spices - stimulants
An attempt was made to explain the great variation in vitamin C content in garden crops, so that vitamin C content may be increased by altering the influencing factors. Ascorbic acid content (AA-ct) was estimated by titration with 2,6-dichlorophenolindophenol. Differences in AA-ct between plant varieties were attributed to polyfactorial genetic differences. Between the AA-ct's of (sub-units of) different genera no correlation with taxonomic order could be found.
AA-ct of rose hips was correlated to the ratio K: Ca: Mg in ash. At the green stage AA-ct was highest when none of the cationic ratios deviated from the average. The same held for the coloured hips, but with other averages (higher K%) and higher AA-ct's. The ideal curve of AA-ct during fruit development may be modified by the weather. A maximum usually occurred in ripe fruit. In leaves it varied with incident solar energy; dehydroascorbic acid showed the opposite course.
Growth substances strongly influenced both ascorbic acid and total vitamin C in the bark of cuttings and in germinating peas. After its formation from sugars, AA acts, particularly on chloroplast surfaces, as a transporter of H from chlorophyll. There it acts as a hydrogen donor and buffer.