We investigated the suitability of Acacia spirorbis Labill., a tropical ectomycorrhizal (ECM) tre... more We investigated the suitability of Acacia spirorbis Labill., a tropical ectomycorrhizal (ECM) tree, as a nurse plant to improve the growth of Tristaniopsis calobuxus Brongn. & Gris seedlings for the restoration of nickel mines in New Caledonia. Rehabilitation of nickel mines in New Caledonia is a major concern. In such harsh soil conditions, ectomycorrhizal (ECM) symbiosis is important for tree growth, survival, and resistance. To improve ecological restoration in New Caledonia, new technical itineraries have undergone experimentation using ECM as a plant nurse, allowing ECM saplings to rapidly acquire a wide range of ECM fungi. We transplanted ECM seedlings of Tristaniopsis calobuxus from the nursery to bare ferralitic soils harbouring some scattered 12-year-old Acacia spirorbis to be used as ECM nurse plants. Using molecular characterisation of ITS rDNA, we characterised ECM fungal communities of A. spirorbis and of T. calobuxus saplings at transplanting time and 13 months later. ...
L'Aquilaria est a l'origine du bois d'agar, ainsi que d'essences recherchees et d... more L'Aquilaria est a l'origine du bois d'agar, ainsi que d'essences recherchees et d'autres produits rares et precieux. Une caracteristique qu'il partage avec un genre proche, le Gyrinops, dote de neuf especes reparties egalement dans le Sud-Est asiatique. Ces arbres sont connus depuis des millenaires pour les vertus de leur bois noir, resineux et odorant. Il s'agit de l'un des bois les plus precieux au monde ; son cout, plus eleve que celui de l'or, peut atteindre 30 000 dollars le kilo. Plusieurs especes du genre Aquilaria sont ainsi recherchees pour leur bois d'agar, et ce particulierement depuis les annees 1970 en Asie du Sud-Est. L'espece la plus exploitee, largement repandue en Malaisie, est A. malaccensis ; citons egalement A. crassna au Laos et A. sinensis en Chine.
Apres un rappel sur la systematique de la tribu des Acacieae et les endomycorhizes et les ectomyc... more Apres un rappel sur la systematique de la tribu des Acacieae et les endomycorhizes et les ectomycorhizes qui sont les deux principaux types mycorhiziens observes chez les arbres, les types mycorhiziens de ce groupe sont etudies. Les resultats de la determination experimentale en serre du type mycorhizien de 32 especes d'Acacia sont ensuite presentes ainsi que les resultats de la determination au champ (Senegal) de l'etat mycorhizien de deux especes d'Acacia australiens. L'ensemble de ces resultats permet de diviser les Acacieae en deux groupes suivant le type mycorhizien : un groupe exclusivement a endomycorhizes et un groupe a endomycorhizes et a ectomycorhizes
Deux projets co-finances par la commission europeenne et les villes de Gembloux (Belgique), Kampo... more Deux projets co-finances par la commission europeenne et les villes de Gembloux (Belgique), Kampong Speu (Cambodge), Xaythani (Laos) et Epinal (France) pour la promotion de la cooperation entre l'Europe et l'Asie du sud-est intitule «Improving the living conditions of poor farmers on the outskirts of Kampong Speu (Cambodia) by diversifying agricultural production» et «Improving the living conditions of poor farmers on the outskirts of Vientiane (Lao PDR) through the develoment of a network to supply the town center with quality agricultural products» fondes sur le postulat: «les paysans pauvres ne souhaitent pas le rester» ont beneficie de l'appui technique et de l'expertise du Cirad. Pour relever ce defi, il a ete choisi de proposer des produits de qualite et originaux a destination de marches solvables, chaines hotelieres, supermarches et restaurants de luxe. Pour cela une cooperative a ete creee afin de mettre en reseau les paysans a qui les formations pour l'...
We implemented complete randomised block designs over a 3-year rotation in two farm sites of sout... more We implemented complete randomised block designs over a 3-year rotation in two farm sites of southern France to test the non-crop legume Crotalaria juncea for biological control of phytoparasitic root-knot nematode populations and green manure effect in greenhouse tunnel vegetable production (lettuce) suffering from recurrent and severe nematode infestation problems. Crotalaria intercrop cultivation was introduced as an alternative cover plant to Sorghum. Crotalaria plants were inoculated at sowing with a cocktail of rhizobium strains, grown for 60-65 days, cut and the residues incorporated into soil; lettuces were then planted and harvested after 75-day growth. Several parameters were measured: Crotalaria plant growth, root nodulation, 15N natural abundance, N concentration and percentage of N2 fixed in C. juncea; subsequent lettuce crop yield and nematode infestation (galls); microbiological impact of Crotalaria in soil and roots. Soil samples were analysed for Corg-N-P contents, ...
Les forets d'Afrique de l'Ouest s'etendent depuis le sud du Senegal jusqu'en Cote... more Les forets d'Afrique de l'Ouest s'etendent depuis le sud du Senegal jusqu'en Cote d'ivoire. Dans ces forets, tes arbres ectomycorhiziens sont localement diversifies et/ou abondants. lis appartiennent aux familles botaniques des Coesalpiniaceae (tribus des Detarieae et des Amherstieae), Dipterocarpaceae (genre Monotes) et Uapacaceae (genre Uapaca). La diversite des champignons ectomycorhiziens associes a ces arbres est importante, notamment parmi les genres Russula, Lactarius, Amanita, Cantharellus et Boletus (s.l.). De nombreuses especes presentes en Afrique de l'Ouest, appartenant aux genres Russula, Amanita et Cantharellus, sont probablement comestibles car elles sont consommees en Afrique de l'Est et en Afrique australe. Cependant, en Afrique de l'Ouest, tres peu d'information est disponible sur la consommation des champignons comestibles par les populations locales. Comme la plupart des produits forestiers non ligneux, les champignons sont sou...
Aquilaria is a tree species belonging to the Thymeleaceae family. When Aquilaria sp. is injured, ... more Aquilaria is a tree species belonging to the Thymeleaceae family. When Aquilaria sp. is injured, it produce agarwood. Agarwood is characterized by a darker wood colour than the healthy one and by a strong perfume that is much esteemed by perfumers and some oriental religious communities. The production of agarwood is presumed to depend of environmental factors, among them fungi. The aim of this work is to obtain an overview of fungi present in Aquilaria sp. from different countries. Aquilaria sp. is endemic to South East Asia including notably Cambodia, Laos and Thailand, where it is cultivated to produce agarwood. In French Guiana, native south East Asian farmers would like to locally produce agarwood in their field. That's why we wonder if fungal communities inducing agarwood are the same between these countries. NGS was used to characterize fungal communities associated with agarwood. 693,961 sequences that cover ITS2 estimated about 250 bp have been obtained. These sequences...
The overexploitation of forests in South-East Asia and their replacement by industrial plantation... more The overexploitation of forests in South-East Asia and their replacement by industrial plantations led to their progressived is appearance in lowland and mountain are as in the last decades. Consequently, policies of forest preservation and the implementation of restoration programs have become priorities in view of sustainable production of timber and soil conservation. However, forest regeneration is highly dependent on the presence of their mycorrhizal symbiotic partners in soils. In the framework of the Mycodipt-BioAsia research project funded by the French Ministry of Foreign and European Affairs in a tripartite partnership between FORDA, FRIM and CIRAD, the first objective of our work was to describe the diversity of ectomycorrhizal trees and that of their associated fungi in two natural forests in South-Sumatra. The Sungai Telang forest site (Muara Bongo District, 01.69635° S; 101.78889° E; alt. 300 m), was chosen as a typical lowland forest dominated by Dipterocarps. The sec...
Le cedre fournit un bois apprecie depuis plusieurs millenaires. Neanmoins, son importance economi... more Le cedre fournit un bois apprecie depuis plusieurs millenaires. Neanmoins, son importance economique reste limitee du fait de sa repartition geographique restreinte au bassin mediterraneen et a l'Himalaya. Cedrus atlantica occupe une place majeure parmi les especes de ce genre, avec des peuplements tres importants au Maroc. Le bloc du Moyen Atlas marocain (130 000 ha) est expose a des maladies cryptogamiques, en particulier le "M'jej", qui diminue de 40% le rendement au sciage. Le M'jej provoque une pourriture fibreuse du bois de coeur. Parmi les nombreux genres et especes fongiques decrits comme responsables du M'jej, tous sont synonymes soit de Phellinus chrysoloma, soit de P. pini. Identifiees suivant les caracteres morphologiques, anatomiques et ecologiques des carpophores, ces deux especes seraient les principaux agents responsables du M'jej. Nos travaux de caracterisation moleculaire d'echantillons recoltes sur des arbres malades et la compara...
Cette mission a ete realisee dans le cadre du projet REDDEL-124 " Mycorrhizal nodules in Aus... more Cette mission a ete realisee dans le cadre du projet REDDEL-124 " Mycorrhizal nodules in Australia and New-Caledonia " finance par l'Ambassade de France a Canberra, I'IRD a Noumea et la DRE du CIRAD. Les differents partenaires scientifiques impliques dans ce projet sont le LSTM, UMR 1063(CIRAD/INRA/IRD/ AGRO-M/UM2),- le laboratoire d'ecologie des forets tropicales humides, CSIRO, Atherton,- I'UR037, Biogeodynamique supergene et geomorphologie tropicale, IR D, Noumea - l'institut agronomique caledonien, Noumea et - l'Universite de Nouvelle-Caledonie. La mission avait pour objets : - de realiser, dans le cadre du projet REDDEL- 124 des prelevements de myconodules en forets naturelles en Australie et en Nouvelle-Caledonie. - de demarrer, en collaboration avec la societe Falconbridge et les partenaires neocaledoniens des etudes sur l'importance des systemes mycorhiziens dans le massif du Koniambo. -de rechercher et mettre en oeuvre de nouvelles poss...
Intraspecific polymorphism exists for many fungus species, making their macroscopic identificatio... more Intraspecific polymorphism exists for many fungus species, making their macroscopic identification difficult. Easily usable molecular markers providing access to information about variability have boosted the development of fungus diversity analyses. For this study, on wood-decaying Aphyllophorales, the main problem to be solved consisted in detecting any existence of intraspecific polymorphism in these fungi, in order to complete and clarify their identification. In order to characterize 98 strains in the CIRAD collection, we developed a rapid discriminant analysis method based on analysing the diversity of partial ribosomal DNA sequences independently of the macro- and microscopic morphological traits of the fruiting bodies required for the identification of genera and species. Adaptation of the Qiagen kit for higher plants made it possible to extract fungal DNA from a few milligrams of mycelium; with most of the strains studied, these DNA extracts enabled us to obtain an ITS ampl...
Acacia spirorbis subsp. spirorbis Labill. is a widespread tree legume endemic to New Caledonia th... more Acacia spirorbis subsp. spirorbis Labill. is a widespread tree legume endemic to New Caledonia that grows in ultramafic (UF) and volcano-sedimentary (VS) soils. The aim of this study was to assess the symbiotic promiscuity of A. spirorbis with nodulating and nitrogen-fixing rhizobia in harsh edaphic conditions. Forty bacterial strains were isolated from root nodules and characterized through (i) multilocus sequence analyses, (ii) symbiotic efficiency and (iii) tolerance to metals. Noteworthy, 32.5% of the rhizobia belonged to the Paraburkholderia genus and were only found in UF soils. The remaining 67.5% isolated from both UF and VS soils belonged to the Bradyrhizobium genus. Strains of the Paraburkholderia genus showed significantly higher N2-fixing capacities than those of Bradyrhizobium genus. Strains of the two genera isolated from UF soils showed high metal tolerance and the respective genes occurred in 50% of strains. This is the first report of both alpha- and beta-rhizobia s...
We investigated the suitability of Acacia spirorbis Labill., a tropical ectomycorrhizal (ECM) tre... more We investigated the suitability of Acacia spirorbis Labill., a tropical ectomycorrhizal (ECM) tree, as a nurse plant to improve the growth of Tristaniopsis calobuxus Brongn. & Gris seedlings for the restoration of nickel mines in New Caledonia. Rehabilitation of nickel mines in New Caledonia is a major concern. In such harsh soil conditions, ectomycorrhizal (ECM) symbiosis is important for tree growth, survival, and resistance. To improve ecological restoration in New Caledonia, new technical itineraries have undergone experimentation using ECM as a plant nurse, allowing ECM saplings to rapidly acquire a wide range of ECM fungi. We transplanted ECM seedlings of Tristaniopsis calobuxus from the nursery to bare ferralitic soils harbouring some scattered 12-year-old Acacia spirorbis to be used as ECM nurse plants. Using molecular characterisation of ITS rDNA, we characterised ECM fungal communities of A. spirorbis and of T. calobuxus saplings at transplanting time and 13 months later. ...
L'Aquilaria est a l'origine du bois d'agar, ainsi que d'essences recherchees et d... more L'Aquilaria est a l'origine du bois d'agar, ainsi que d'essences recherchees et d'autres produits rares et precieux. Une caracteristique qu'il partage avec un genre proche, le Gyrinops, dote de neuf especes reparties egalement dans le Sud-Est asiatique. Ces arbres sont connus depuis des millenaires pour les vertus de leur bois noir, resineux et odorant. Il s'agit de l'un des bois les plus precieux au monde ; son cout, plus eleve que celui de l'or, peut atteindre 30 000 dollars le kilo. Plusieurs especes du genre Aquilaria sont ainsi recherchees pour leur bois d'agar, et ce particulierement depuis les annees 1970 en Asie du Sud-Est. L'espece la plus exploitee, largement repandue en Malaisie, est A. malaccensis ; citons egalement A. crassna au Laos et A. sinensis en Chine.
Apres un rappel sur la systematique de la tribu des Acacieae et les endomycorhizes et les ectomyc... more Apres un rappel sur la systematique de la tribu des Acacieae et les endomycorhizes et les ectomycorhizes qui sont les deux principaux types mycorhiziens observes chez les arbres, les types mycorhiziens de ce groupe sont etudies. Les resultats de la determination experimentale en serre du type mycorhizien de 32 especes d'Acacia sont ensuite presentes ainsi que les resultats de la determination au champ (Senegal) de l'etat mycorhizien de deux especes d'Acacia australiens. L'ensemble de ces resultats permet de diviser les Acacieae en deux groupes suivant le type mycorhizien : un groupe exclusivement a endomycorhizes et un groupe a endomycorhizes et a ectomycorhizes
Deux projets co-finances par la commission europeenne et les villes de Gembloux (Belgique), Kampo... more Deux projets co-finances par la commission europeenne et les villes de Gembloux (Belgique), Kampong Speu (Cambodge), Xaythani (Laos) et Epinal (France) pour la promotion de la cooperation entre l'Europe et l'Asie du sud-est intitule «Improving the living conditions of poor farmers on the outskirts of Kampong Speu (Cambodia) by diversifying agricultural production» et «Improving the living conditions of poor farmers on the outskirts of Vientiane (Lao PDR) through the develoment of a network to supply the town center with quality agricultural products» fondes sur le postulat: «les paysans pauvres ne souhaitent pas le rester» ont beneficie de l'appui technique et de l'expertise du Cirad. Pour relever ce defi, il a ete choisi de proposer des produits de qualite et originaux a destination de marches solvables, chaines hotelieres, supermarches et restaurants de luxe. Pour cela une cooperative a ete creee afin de mettre en reseau les paysans a qui les formations pour l'...
We implemented complete randomised block designs over a 3-year rotation in two farm sites of sout... more We implemented complete randomised block designs over a 3-year rotation in two farm sites of southern France to test the non-crop legume Crotalaria juncea for biological control of phytoparasitic root-knot nematode populations and green manure effect in greenhouse tunnel vegetable production (lettuce) suffering from recurrent and severe nematode infestation problems. Crotalaria intercrop cultivation was introduced as an alternative cover plant to Sorghum. Crotalaria plants were inoculated at sowing with a cocktail of rhizobium strains, grown for 60-65 days, cut and the residues incorporated into soil; lettuces were then planted and harvested after 75-day growth. Several parameters were measured: Crotalaria plant growth, root nodulation, 15N natural abundance, N concentration and percentage of N2 fixed in C. juncea; subsequent lettuce crop yield and nematode infestation (galls); microbiological impact of Crotalaria in soil and roots. Soil samples were analysed for Corg-N-P contents, ...
Les forets d'Afrique de l'Ouest s'etendent depuis le sud du Senegal jusqu'en Cote... more Les forets d'Afrique de l'Ouest s'etendent depuis le sud du Senegal jusqu'en Cote d'ivoire. Dans ces forets, tes arbres ectomycorhiziens sont localement diversifies et/ou abondants. lis appartiennent aux familles botaniques des Coesalpiniaceae (tribus des Detarieae et des Amherstieae), Dipterocarpaceae (genre Monotes) et Uapacaceae (genre Uapaca). La diversite des champignons ectomycorhiziens associes a ces arbres est importante, notamment parmi les genres Russula, Lactarius, Amanita, Cantharellus et Boletus (s.l.). De nombreuses especes presentes en Afrique de l'Ouest, appartenant aux genres Russula, Amanita et Cantharellus, sont probablement comestibles car elles sont consommees en Afrique de l'Est et en Afrique australe. Cependant, en Afrique de l'Ouest, tres peu d'information est disponible sur la consommation des champignons comestibles par les populations locales. Comme la plupart des produits forestiers non ligneux, les champignons sont sou...
Aquilaria is a tree species belonging to the Thymeleaceae family. When Aquilaria sp. is injured, ... more Aquilaria is a tree species belonging to the Thymeleaceae family. When Aquilaria sp. is injured, it produce agarwood. Agarwood is characterized by a darker wood colour than the healthy one and by a strong perfume that is much esteemed by perfumers and some oriental religious communities. The production of agarwood is presumed to depend of environmental factors, among them fungi. The aim of this work is to obtain an overview of fungi present in Aquilaria sp. from different countries. Aquilaria sp. is endemic to South East Asia including notably Cambodia, Laos and Thailand, where it is cultivated to produce agarwood. In French Guiana, native south East Asian farmers would like to locally produce agarwood in their field. That's why we wonder if fungal communities inducing agarwood are the same between these countries. NGS was used to characterize fungal communities associated with agarwood. 693,961 sequences that cover ITS2 estimated about 250 bp have been obtained. These sequences...
The overexploitation of forests in South-East Asia and their replacement by industrial plantation... more The overexploitation of forests in South-East Asia and their replacement by industrial plantations led to their progressived is appearance in lowland and mountain are as in the last decades. Consequently, policies of forest preservation and the implementation of restoration programs have become priorities in view of sustainable production of timber and soil conservation. However, forest regeneration is highly dependent on the presence of their mycorrhizal symbiotic partners in soils. In the framework of the Mycodipt-BioAsia research project funded by the French Ministry of Foreign and European Affairs in a tripartite partnership between FORDA, FRIM and CIRAD, the first objective of our work was to describe the diversity of ectomycorrhizal trees and that of their associated fungi in two natural forests in South-Sumatra. The Sungai Telang forest site (Muara Bongo District, 01.69635° S; 101.78889° E; alt. 300 m), was chosen as a typical lowland forest dominated by Dipterocarps. The sec...
Le cedre fournit un bois apprecie depuis plusieurs millenaires. Neanmoins, son importance economi... more Le cedre fournit un bois apprecie depuis plusieurs millenaires. Neanmoins, son importance economique reste limitee du fait de sa repartition geographique restreinte au bassin mediterraneen et a l'Himalaya. Cedrus atlantica occupe une place majeure parmi les especes de ce genre, avec des peuplements tres importants au Maroc. Le bloc du Moyen Atlas marocain (130 000 ha) est expose a des maladies cryptogamiques, en particulier le "M'jej", qui diminue de 40% le rendement au sciage. Le M'jej provoque une pourriture fibreuse du bois de coeur. Parmi les nombreux genres et especes fongiques decrits comme responsables du M'jej, tous sont synonymes soit de Phellinus chrysoloma, soit de P. pini. Identifiees suivant les caracteres morphologiques, anatomiques et ecologiques des carpophores, ces deux especes seraient les principaux agents responsables du M'jej. Nos travaux de caracterisation moleculaire d'echantillons recoltes sur des arbres malades et la compara...
Cette mission a ete realisee dans le cadre du projet REDDEL-124 " Mycorrhizal nodules in Aus... more Cette mission a ete realisee dans le cadre du projet REDDEL-124 " Mycorrhizal nodules in Australia and New-Caledonia " finance par l'Ambassade de France a Canberra, I'IRD a Noumea et la DRE du CIRAD. Les differents partenaires scientifiques impliques dans ce projet sont le LSTM, UMR 1063(CIRAD/INRA/IRD/ AGRO-M/UM2),- le laboratoire d'ecologie des forets tropicales humides, CSIRO, Atherton,- I'UR037, Biogeodynamique supergene et geomorphologie tropicale, IR D, Noumea - l'institut agronomique caledonien, Noumea et - l'Universite de Nouvelle-Caledonie. La mission avait pour objets : - de realiser, dans le cadre du projet REDDEL- 124 des prelevements de myconodules en forets naturelles en Australie et en Nouvelle-Caledonie. - de demarrer, en collaboration avec la societe Falconbridge et les partenaires neocaledoniens des etudes sur l'importance des systemes mycorhiziens dans le massif du Koniambo. -de rechercher et mettre en oeuvre de nouvelles poss...
Intraspecific polymorphism exists for many fungus species, making their macroscopic identificatio... more Intraspecific polymorphism exists for many fungus species, making their macroscopic identification difficult. Easily usable molecular markers providing access to information about variability have boosted the development of fungus diversity analyses. For this study, on wood-decaying Aphyllophorales, the main problem to be solved consisted in detecting any existence of intraspecific polymorphism in these fungi, in order to complete and clarify their identification. In order to characterize 98 strains in the CIRAD collection, we developed a rapid discriminant analysis method based on analysing the diversity of partial ribosomal DNA sequences independently of the macro- and microscopic morphological traits of the fruiting bodies required for the identification of genera and species. Adaptation of the Qiagen kit for higher plants made it possible to extract fungal DNA from a few milligrams of mycelium; with most of the strains studied, these DNA extracts enabled us to obtain an ITS ampl...
Acacia spirorbis subsp. spirorbis Labill. is a widespread tree legume endemic to New Caledonia th... more Acacia spirorbis subsp. spirorbis Labill. is a widespread tree legume endemic to New Caledonia that grows in ultramafic (UF) and volcano-sedimentary (VS) soils. The aim of this study was to assess the symbiotic promiscuity of A. spirorbis with nodulating and nitrogen-fixing rhizobia in harsh edaphic conditions. Forty bacterial strains were isolated from root nodules and characterized through (i) multilocus sequence analyses, (ii) symbiotic efficiency and (iii) tolerance to metals. Noteworthy, 32.5% of the rhizobia belonged to the Paraburkholderia genus and were only found in UF soils. The remaining 67.5% isolated from both UF and VS soils belonged to the Bradyrhizobium genus. Strains of the Paraburkholderia genus showed significantly higher N2-fixing capacities than those of Bradyrhizobium genus. Strains of the two genera isolated from UF soils showed high metal tolerance and the respective genes occurred in 50% of strains. This is the first report of both alpha- and beta-rhizobia s...
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