Les mycorhizes en pratique agronomique : acquis et suggestions

International audience

Glomales species associated with surface and deep rhizosphere of Faidherbia albida in Senegal

Five arbuscular mycorrhizal (AM) fungal species were isolated and propagated from surface and deep rhizospheres of Faidherbia albida trees growing in two ecoclimatic zones of West Africa: the semi-arid Sahelian and the more humid Sudano-Guinean areas. Of these species, Glomus aggregatum, Glomus caledonium, and Glomus mosseae were trapped by F. albida roots when cultivated with either surface or deep soils. Glomus fasciculatum was found exclusively at the semi-arid Sahelian sites of Louga and Diokoul and Gigaspora margarita was isolated only from 16.5-m and 34-m-deep samples. Comparable glomalean fungal species richness was identified in deep (1.5–34 m) and surface (0.15 m) samples. The isol…

Influence des mycorhizes à arbuscules sur la tolérance à un stress hydrique de quatre arbres fruitiers Balanites aegyptiaca (L.) Del., Parkia biglobosa (Jacq.) Benth., Tamarindus indica L. et Ziziphus mauritiana Lam.

National audience

Effect of incorporation of Brassica napus L. residues in soils on mycorrhizal fungus colonisation of roots and phosphorus uptake by maize (Zea mays L.)

International audience; Plants in the Brassicaceae family are known to contain thioglucoside compounds that produce isothiocyanates when tissues are disrupted. These chemicals have a negative effect on soil-borne fungal pathogens, and possibly on vesicular-arbuscular mycorrhizal (AM) fungi. We investigated the effect of incorporation of Brassica napus L. residues in a soil on mycorrhizal colonisation of roots, P uptake and growth of following maize (Zea mays L.) crop. A pot experiment was carried out in a glasshouse with pre-inoculation with Glomus intraradices (+I and -I), incorporation of B. napus L. residues (+R and -R) and mineral P fertilization (+P and -P) as studied factors. The soil…

Les mycorhizes, situation et perspectives pour le pépiniériste et l'horticulteur

National audience

Impact of sewage sludge disposal on dissolved and sediment associated phosphorus transferred from terrestrial to aquatic systems

International audience

Méthode de coloration pour l'observation et le comptage des endomycorhises à vésicules et arbuscules sur racines de maïs

Cette méthode permet d'observer et de quantifier les Mycorhizes à Vésicules sur des racines de maïs sous loupe binoculaire (X 60)

Acacias du Sahel : un espoir pour l'agriculture

National audience

Soil and fertilizer phosphorus : effects on plant P supply and mycorrhizal development

Plants require adequate P from the very early stages of growth for optimum crop production. Phosphorus supply to the crop is affected by soil P, P fertilizer management and by soil and environmental conditions influencing P phytoavailability and root growth. Phosphorus uptake in many crops is improved by associations with arbuscular mycorrhizal fungi. Cropping system and long-term input of P through fertilizers and manures can influence the amount and phytoavailability of P in the system and the development of mycorrhizal associations. Optimum yield potential requires an adequate P supply to the crop from the soil or from P additions. Where early-season P supply is low, P fertilization may…

Mycorrhizae in crop production

International audience; It has been a revelation that, strictly speaking, most plants do not have roots but rather mycorrhizae, a fact that has had tremendous consequences on the life of plants and the evolution of soil-plant systems. The research on arbuscular mycorrhizal (AM) symbioses has been intensive over the past forty years and we have learned a lot on the physiology, biology, ecology, and genetics of the symbiosis and the fungi involved in it. Most important, it appeared that cropping systems could be more sustainable with the management of AM fungi and reduced reliance on agrochemicals. The extraradical mycelia of AM fungi are an essential link between the plants, which are the co…

Growth stimulation of apple trees by VA mycorrhiza inoculation in unsterilized soil under field conditions

International audience

Mycorhizes et nutrition phosphatée des plantes

International audience

The influence of different endomycorrhizal fungi on the growth of oat, strawberry, leek and apple tree cultivated in the greenhouse

International audience

The effect of VA mycorrhizal fungus (Glomus epigaeus) on the growth of two apple tree clones propagated in vitro

International audience

Culture des champignons mycorhiziens du genre Glomus in vitro : procédés et test de viabilité

International audience

Growth and nutrient mineral status of Faidherbia albida seedlings as influenced by inoculation with Glomus mosseae, Bradyrhizobium and fertilisation

International audience

Attractive introductions of fast-growing australian acacias in irrigated areas in Senegal (West Africa) : real potentialities for soudano-sahelian countries in Africa

International audience

Travail du sol et champignons mycorhiziens

National audience

Influence of field crop plantations on microbial characteristics of runoff water: effect on plant growth and soil functioning

International audience

Receptiveness of some tropical soils from banana fields in Martinique to the arbuscular fungus Glomus intraradices

Tropical crops of great economic importance such as banana are known to benefit from mycorrhizal association. Development and survival of introduced mycorrhizal propagules depend not only on the crops but mainly on the edaphic conditions and soil types where the symbiosis is established. Seven soils from banana fields of Martinique were sampled and tested to determine their receptiveness to mycorrhizal inoculation. Biological tests involved cultivation of 10 leek plantlets in pots containing soil inoculated with a range of mycorrhizal propagule densities (3, 10, 30, 100, 300 propagules/100 g soil). Mycorrhizal colonisation was recorded after 2 weeks of growth and tentatively correlated with…

Applications pratiques des endomycorhizes VA

National audience

Approche qualitative et quantitative de l'effet de la jachère sur des populations de champignons mycorhiziens à arbuscules

National audience

Utilisation des mycorhizes et des composts pour la plantation de vitroplants de bananier

National audience

Growth stimulation of seventeen fallow leguminous plants inoculated with Glomus aggregatum in Senegal

Abstract Tropical legumes from fallowed areas in Senegal were inoculated with a tropical strain of Glomus aggregatum to test their relative mycorrhizal dependency in a greenhouse experiment. Twelve species among the seventeen tested showed a significant growth increase when mycorrhizal. Their mycorrhizal dependency varied from 92.7% for Indigofera stenophylla to 26.2% for Prosopis julifora . A significant positive correlation was found between mycorrhizal dependency and root hair length. The results confirm the high mycorrhizal dependency of legumes which are economically very important in the restoration of soil fertility of fallowed areas in the Sahelian and Soudano-Sahelian zones.

The mycorrhizal soil infectivity and arbuscular mycorrhizal fungal spore communities in soils of different aged fallows in Senegal

This work was carried out to determine the influence of the duration of fallow and of physico-chemical components of soils on the distribution of endomycorrhizal fungal spores and the mycorrhizal soil infectivity. The mycorrhization of indigenous plants from the fallows was examined and it was concluded that, except for Cassia obtusifolia, fungal colonization was poorly developed. No correlation was established between spore populations and duration of fallow or between grazed and fenced areas. The relationships between abundance of mycorrhizal spores and the physico-chemical characteristics of the soils were markedly variable among species of mycorrhizal fungi. The results did not provide …

Effects of VA status on the growth of various plant species in natural and fumigated soil

International audience

Fertilisation azotée du blé de printemps

National audience

Première contribution à l'étude des mycorhizes des îles Kerguelen

Abstract Until recently mycorrhizae had not been studied in the Antarctic region. Some studies have demonstrated that mycorrhizae occur in some southern circumpolar islands. This paper gives the first results on the mycorrhizae in the Kerguelen islands (Sub-antarctic). Twenty-one plant root systems, fixed in the field, were examined microscopically in the laboratory to determine their mycorrhizal status. No ectomycorrhiza, arbutoid or ericoid were noted. Six plant species showed vesicular arbuscular mycorrhizae: Ranunculus biternatus, Galium antarcticum, Festuca erecta, Poa kerguelensis, Agrostis magellanica and Poa annua. However, the mycorrhizal status varied according to the site studied.

Mycorrhizal dependency of several plant species under field conditions in a soil of moderate P. fertility

International audience

Analyse spatiale et fonctionnelle de la diversité d'un système symbiotique en milieu insulaire et continental : cas du Pterocarpus officinalis Jack. et de ses microorganismes associés en foret marécageuse

National audience

Estimation of the population density of arbuscular mycorrhizal fungi in soils used for intensive banana cultivation in Martinique

International audience

L'intérêt des mycorhizes

National audience

Impact de l'épandage des boues sur le phosphore dissous et particulaire des écoulements de surface

Abstract The aim of this study was to assess the effect of land application of sewage sludge on phosphorus (P) losses during intense rainfall. Three rainfall simulations (40 mm h−1 of 30 min duration) were conducted on a field amended with sewage sludge. The overland flow water (OFW) was monitored and sampled every minute. The suspended solid, the dissolved and total phosphorus (respectively SS, TP and DP) concentrations were analysed. The forms of particulate bound P (PP) were investigated. Several results stem from this experiment: (a) sludge application induced a large increase in the DP content of the OFW; the concentrations obtained (0.15–0.57 mg l−1) were shown to result from desorpti…

L'inoculum endomycorhizien : composition et méthodes d'inoculation

National audience

Symbiose mycorhizienne chez les plantes agricoles et horticoles

National audience

Effects of N, P, K fertilizers on Gigaspora calospora vesicular-arbuscular endomycorrhizae on Allium cepa

International audience

Does incorporation of Brassica napus L. resudues in soil affect mycorrhizal colonisation of roots and P uptake by maize (Zea mays L.) ?

International audience

A mycorrhiza helper bacterium enhances ectomycorrhizal and endomycorrhizal symbiosis of Australian Acacia species.

The aims of this study were to test the effects of a mycorrhiza helper bacterium (MHB), Pseudomonas monteilii strain HR13 on the mycorrhization of (1) an Australian Acacia, A. holosericea, by several ectomycorrhizal fungi or one endomycorrhizal fungus Glomus intraradices, and (2) several Australian Acacia species by Pisolithus alba strain IR100 under glasshouse conditions. Bacterial inoculant HR13 significantly promoted ectomycorrhizal colonization for all the Acacia species, from 45.8% ( A. mangium) to 70.3% ( A. auriculiformis). A stimulating effect of HR13 on the ectomycorrhizal establishment was recorded with all the fungal isolates (strains of Pisolithus and Scleroderma). The same effe…

Mobilisation des phosphates naturels de Kodjari par des jujubiers (Ziziphus mauritiana Lam.) mycorhizés dans un sol acidifié avec de la tourbe

National audience

Influence des conditions d'oxydo-réduction sur la disponibilité du phosphore de boues de station d'épuration appréciée par la méthode de dilution isotopique

National audience

Méthode de coloration pour l'observation et le comptage des endomycorhizes à vésicules et arbuscules sur racines de maïs

National audience

Growth response of the saltbush Atriplex nummularia L. to inoculation with the arbuscular mycorrhizal fungus Glomus intraradices

Abstract Plantlets of Atriplex nummularia were inoculated with the arbuscular mycorrhizal fungi Glomus intraradices in a pot experiment. Plants were grown in a low P soil. Highly significant growth response of a Chenopodiaceae was recorded for the first time. Mycorrhizal colonization of roots was well developed, internal hyphae and vesicles were observed, but not arbuscules. These observations suggest that arbuscules are not necessary to obtain significant growth stimulation from mycorrhizal inoculation. Atriplex nummularia is already used as forage crops, its high mycorrhizal dependency offers possibilities to develop this production and revegetation strategies.

Biofonctionnements des sols tropicaux et mode de gestion des terres

L'effet de deux peuplements de nématodes phytoparasites a été étudié en conditions contrôlées sur la croissance du mil (#Pennisetum glaucum$). Les plants de mil (cv. IKMV 8201) ont été cultivés en pots sur du col collecté au Sud du Sénégal dans un champ cultivé (sol cultivé) et dans une jachère de 17 ans (sol de jachère). La moitié du sol de chacun des prélèvements à été stérilisée. Pour compenser l'effet de la stérilisation, six cycles de cultures de mil de deux mois ont été faits avant l'expérimentation. A l'issu de cette période, trois espèces ont été observées sur le sol cultivé non stérilisé : #Scutellonema cavanessi$, #Tylenchorhynchus gladiolatus$ et #Ditylenchus myceliophagus$, dans…

Glomus kerguelense sp. Nov., a new glomales species from sub-antartic

International audience

Impact des mycorhizes en climat méditerranéen

National audience

Influence des phosphates naturels et des mycorhizes à vésicules et à arbuscules sur la croissance et la nutrition minérale de Zizyphus mauritiana Lam. dans un sol à pH alcalin

Rock phosphate and vesicular-arbuscular mycorrhiza effects on growth and mineral nutrition of Zizyphus mauritiana Lam. in an alkaline soil. The influence of vesicular-arbuscular mycorrhizae (VAM) and rock phosphate (RP) was studied on jujube (Zizyphus mauritiana Lam.), a multipurpose fruit tree in Sahelian agroforestry systems. Jujubes were inoculated or not by Clomus manihotis Howeler, Sieverding & Schenck in an alkaline sandy soil to which were added five levels of RP (12 % of P) : 0.00, 0.31, 0.62, 1.25 et 2.50 g P/kg of soil, equivalent to 0, 775, 1 550, 3 125 et 6 250 kg P ha -1 . The jujubes seedlings grew poorly without mycorrhizal colonization and without RP applications (figures 1a…

Soil Nutrient and Water providers: How Arbuscular Mycorrhizal Mycelia Support Plant Performance in a Resource-Limited World

International audience

Les mycorhizes : la nouvelle révolution verte

National audience

Gestion des peuplements de nématodes phytoparasites au moyen des facteurs biotiques et abiotiques telluriques

National audience

Des vésicules de Glomus encapsulées : un inoculum mycorhizien pour les vitroplants et les vitrotubercules de pomme de terre

Potential of Crotalaria species as green manure crops for the management of pathogenic nematodes and beneficial mycorrhizal fungi

On the basis of preliminary experiments, some Crotalaria species from Senegal were investigated to determine (1) their susceptibility to Meloidogyne javanica and M. incognita compared to a sensitive host (tomato), (2) their mycorrhizal and rhizobial responses, and (3) the effect of their cultivation on the mycorrhizal soil infectivity. The nematode invasion rates on Crotalaria spp. ranked from 0.17 to 7.17% and from 0.58 to 5.25%, respectively, for M. incognita and M. javanica, vs. 97% and 77% on tomato. Moreover, the inoculated J2 which invaded tomatoes developed into adult females, while those on Crotalaria spp. rarely developed beyond the third stage, confirming that all Crotalaria spp. …