35 research outputs found
A randomised double-blind placebo-controlled trial investigating the behavioural effects of vitamin, mineral and n-3 fatty acid supplementation in typically developing adolescent schoolchildren
This material is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © 2015 The Authors. Published by Cambridge University Press.Nutrient deficiencies have been implicated in anti-social behaviour in schoolchildren; hence, correcting them may improve sociability. We therefore tested the effects of vitamin, mineral and n-3 supplementation on behaviour in a 12-week double-blind randomised placebo-controlled trial in typically developing UK adolescents aged 13–16 years (n 196). Changes in erythrocyte n-3 and 6 fatty acids and some mineral and vitamin levels were measured and compared with behavioural changes, using Conners’ teacher ratings and school disciplinary records. At baseline, the children’s PUFA (n-3 and n-6), vitamin and mineral levels were low, but they improved significantly in the group treated with n-3, vitamins and minerals (P=0·0005). On the Conners disruptive behaviour scale, the group given the active supplements improved, whereas the placebo group worsened (F=5·555, d=0·35; P=0·02). The general level of disciplinary infringements was low, thus making it difficult to obtain improvements. However, throughout the school term school disciplinary infringements increased significantly (by 25 %; Bayes factor=115) in both the treated and untreated groups. However, when the subjects were split into high and low baseline infringements, the low subset increased their offences, whereas the high-misbehaviour subset appeared to improve after treatment. But it was not possible to determine whether this was merely a statistical artifact. Thus, when assessed using the validated and standardised Conners teacher tests (but less clearly when using school discipline records in a school where misbehaviour was infrequent), supplementary nutrition might have a protective effect against worsening behaviour.Peer reviewe
Stratégie d'amélioration de la qualité des plants forestiers et des reboisements méditerranéens par utilisation de la mycorhization contrôlée en pépinière
Technique de production hors-sol du Cèdre de l'Atlas
This communication presents the results obtained in the field of choosing container, substrate, nutrition and controlled mycorrhization. It brings into light the necessity of using anti-coiling containers with a 400 cm3 minimum volume. Substrate nature plays an important part in root development and seedling physiology. High quality seddlings are now being grown on a mixture of 50% long fiber peat and 50% composted pine bark. Supplying mineral elements to this substrate prooves essential to allow seedling development. These supplies can consist in weekly waterings with a nutrient solution, completing a fertilizer incorporated to subtrate during its preparation. As regards controlled mycorrhization, the first results show that inoculation success is tightly bound to inoculum nature. Only sporal inoculation with Tuber albidum allowed to get mycorrhized seedlings showing better survival and growth rates than non mycorrhized seedlings. / Les auteurs présentent les résultats obtenus en matière de choix de conteneurs et de substrats, de nutrition et de mycorhization contrôlée et de techniques de reboisement. Ils mettent en évidence la nécessité d'utiliser des conteneurs sans fond d'un volume au moins égal à 400 cm3. La nature du substrat joue également un rôle important dans le développement du système racinaire et la physiologie du plant. Les plants de qualité sont actuellement produits sur un mélange tourbe à longue fibre (50%) écorce de pin compostée (50%). Dans ce substrat inerte, l'apport d'éléments minéraux s'avère indispensable pour permettre le bon développement du plant. Ces apports peuvent être envisagés sous forme d'arrosages hebdomadaires avec une solution nutritive complète en complément d'un engrais retard incorporé au substrat lors de sa préparation. Les premiers essais en matière de mycorhization contrôlée montrent que la réussite de l'inoculation est fortement liée à nature de l'inoculum : seule l'inoculation sporale par Tuber albidum nous a permis d'obtenir des plants mycorhizés ayant un meilleur comportement en plantation que les plants non mychorizés
Molecular markers detecting an ectomycorrhizal Suillus collinitus strain on Pinus halepensis roots suggest successful inoculation and persistence in Mediterranean nursery and plantation
Survival of the ectomycorrhizal fungal strain Suillus collinitus Sc-32 on Pinus halepensis after inoculation and outplanting was monitored in a Mediterranean plantation. Three molecular fingerprints were developed: RFLP of the internal transcribed spacer ribosomal DNA, intersimple sequence repeat, and a specific sequence-characterized amplified region marker. The inoculant was demonstrated to survive on inoculated seedlings 4 years after outplanting (56 months after inoculation), although S. collinitus was not fruiting. The designed markers set allows reliable and inexpensive monitoring of inoculated seedlings and suggests that S. collinitus is suitable for inoculation of Mediterranean Pinus. These data are discussed in the framework of suilloid population ecolog
Essai d'introduction dans un aéronosol calcaire de petite-Camargue de pins pignons (Pinus pinea L.) mycorhisés par Suillus collinitus
Two reforestation plots of Pinus pinea were set up (1988 and 1990) in "petite-Camargue" area. We measured the effects of controlled mycorhizal infection with Suillus collinitus and the effect of mineral nutrition in nursery on the survival rate and growth in plantation. Controlled mycorhization with Suillus collinitus n°2 increased plants growth in nursery and this increase is always observed 6 years after plantation. Mycorhization allowed the production of plants in relation with the marketing reglementation and reduced the mineral nutrition supply in nursery. / Deux plantations expérimentales (1988 et 1990) ont été effectuées pour mettre en évidence l'effet de la fertilisation en pépinière sur le comportement du Pin pignon dans un arénosol calcaire de petite Camargue. Dans les 2 essais, la mycorhization a eu un effet positif sur la croissance des plants en pépinière. Cet effet s'est maintenu au cours des 6 premières années de plantation. La mycorhisation contrôlée par Suillus collinitus a permis la production de plants conformes aux normes de commercialisation moyennant une utilisation réduite d'engrais
Growth, carbon dioxide assimilation capacity and water-use efficiency of Pinus pinea L seedlings inoculated with different ectomycorrhizal fungi
Three months after sowing, seedlings of Pinus pinea L grown in a nursery on a perlite-Sphagnum peat mixture were inoculated with different ectomycorrhizal fungi: Rhizopogon roseolus and Suillus collinitus (2 strains: 1 and 2). The growth medium was maintained well-watered and was fertilized with a dilute Coïc-Lesaint (N, P, K; 3, 2, 7.5 g l-1) solution. Fertilization was stopped at the end of the first growing season (October) and growth and gas exchange parameters of the seedlings were assessed prior to the beginning of their second growth season. Inoculation with the 2 S collinitus strains led to the greatest plant elongation, but biomass growth was greatest with R roseolus. Whole plant CO2 assimilation capacity in the R roseolus treatment was 1.83 times that in the control treatment and 1.38 times that in the S collinitus 2 treatment. The plants infected by R roseolus and S collinitus 1 had similar whole plant CO2 assimilation capacities, but root and total plant biomass were significantly higher in the R roseolus treatment. This difference could be due partly to greater carbon diversion by the fungal associate in the case of S collinitus 1. Mean water-use efficiency (WUE = CO2 assimilation rate/transpiration rate) of the inoculated seedlings (pooled mean value 7.29 mol kmol-1) was significantly (P < 0.05) higher than that of the controls (5.06 mol kmol-1). This is linked to the double tendency, neither being statistically significant, of the infected plants to exhibit higher CO2 assimilation rates and lower transpiration rates than the controls.Croissance, capacité d'assimilation de CO2 et efficience de l'eau de plants de Pinus pinea L inoculés par différents champignons ectomycorhiziens. Des plants de Pinus pinea L âgés de 3 mois et cultivés en pépinière sur un subtrat à base de perlite et de tourbe blonde de Sphaigne, ont été inoculés avec différents champignons ectomycorhiziens : Rhizopogon roseolus et Suillus collinitus (2 souches, 1 et 2). Le substrat était maintenu en permanence à un niveau hydrique non limitant et était fertilisé à l'aide d'une solution diluée de type Coïc-Lesaint (N, P, K ; 3, 2, 7.5 g l -1). La fertilisation a été interrompue à la fin de la première saison de végétation des plants (octobre). On a mesuré les caractéristiques de taille et de biomasse des plants ainsi que les échanges gazeux de CO 2 et H2O avant le début de la seconde saison de végétation (février). La hauteur des plants était la plus forte pour les plants inoculés avec les 2 souches de S collinitus, mais la croissance pondérale état la plus élevée dans le cas des plants inoculés avec R roseolus. La capacité totale d'assimilation de CO2 des plants inoculés par R roseolus représentait 183 % par rapport à la capacité des plants non mycorhizés et 138 % par rapport au traitement S collinitus 2. Les plants inoculés par R roseolus et S collinitus 1 étaient caractérisés par des capacités totales d'assimilation de CO 2 similaires, mais la biomasse racinaire ainsi que la biomasse totale des plants étaient plus élevées dans le cas du traitement R roseolus. Cette différence pourrait être liée, du moins partiellement, à une utilisation plus importante du carbone assimilé, par l'associé fongique, dans le cas de S collinitus 1. L'efficience de l'eau (WUE = taux d'assimilation de CO2/taux de transpiration) moyenne des plants mycorhizés (valeur moyenne générale 7.29 mol kmol-1) était significativement supérieure (P < 0.05) à celle des plants non mycorhizés (5.06 mol kmol-1). Cela est à relier à la double tendance, non statistiquement significative pour chacune des 2 composantes considérées séparément, des plants mycorhizés à présenter des valeurs moyennes de taux d'assimilation de CO2 (A) plus élevées et de taux de transpiration (E) plus faibles que les plants non mycorhizés
Fertilisation minérale et fructification des champignons supérieurs en hêtraie
International audienc
Nutrition minérale et mycorhization contrôlée : compte rendu des travaux effectués en 1993
This document describes the 1993 programm about mediterranean forest seedling mineral nutrition and controlled mycorrhization. / Synthèse des travaux 1993 sur la nutrition minérale et la mycorhization contrôlée des plants forestiers méditerranéens
Phylogenetic diversity of Moroccan cork oak woodlands fungi
Interspecific variation among 87 sporocarps of fungi belonging to 15 genera and 39 species were evaluated by analyzing the internal transcribed spacer (ITS) of the rDNA region using restriction fragment length polymorphism (RFLP). The ITS region was first amplified by polymerase chain reaction (PCR) with specific primers and then cleaved with different restriction enzymes. Amplification products, which ranged between 500 and 950 base pairs (bp), were obtained for all the isolates analyzed. The degree of polymorphism observed did not allow proper identification of most of the species. Cleavage of amplified fragments with the restriction enzymes Alu I, EcoR I and Hinf I revealed extensive polymorphism. The fifteen genera and most species presented specific restriction patterns. The only species not identifiable by a specific pattern belonged to the genera Russula (R. decipiens and R. straminea). These species might be considered as closely related species. The Pisolithus sporocarps had two ITS-RFLP types with one dominating. ITS sequencing confirms that the two RFLP types correspond to two distinct species of Pisolithus. Our data show the potential of ITS region PCR-RFLP for the molecular characterization of ectomycorrhizal fungi and their identification and monitoring in artificial inoculation programs