Ecology and biodiversity of the symbiosis Frankia-Casuarinaceae in New Caledonia Deuxième conférence internationale sur l'écologie des milieux serpentiniques, Nouméa, 31 juillet-5 août 1995 : résumés = Second international conference on serpentine ecology, Noumea, july 31-august 5, 1995 : abstracts /Navarro, Elisabeth /Gauthier, Daniel Lesage, G. Simonet, P. /Jaffré, Tanguy /Rinaudo, Gérard SYMBIOSE FIXATION BIOLOGIQUE DE L'AZOTE INOCULATION BIODIVERSITE The native region of Casuarinaceae family (actinorhizal plants) is Oceania (Australia and Indo-Pacific islands). In New Caledonia, in spite of the reduced area, a great number of endemic Casuarinaceae are present. In fact, 8 species of Gymnostoma out of the 18 which make up this genus and 1 species of Casuarina are originated from New Caledonia. The two genera, except 1 species, occur in soils derivated from ultramafic rock and are adapted to poor and toxic soils. Furthermore, actinorhizal plants can establish nitrogen-fixing symbioses with the slow growing actinomycete Frankia. Because of their ecological characteristics, actinorhizal plants frequently occur as pioneer vegetation and are used in the rehabilitation of degraded sites. This work was a first study of the ecology of the symbiosis Casuarinaceae-Frankia in New Caledonia. It was focused on two major topics. The first part will be concerned with the symbiosis, particularly with cross-inoculation trials using crushed nodule suspension as inoculum. The biodiversity of the microsymbiot Frankia, in relation to plants species and soil, will be analysed in the second part. The results obtained show that this symbiosis is characterized by a great biodiversity. Inside the Gymnostoma group, no host specificity was observed. These results were obtained by cross-inoculation tests and molecular characterization of Frankia. Furthermore, no correlation was shown between site or soil and the diversity of Frankia strains. (Résumé d'auteur) ORSTOM 1995 text https://www.documentation.ird.fr/hor/fdi:010005648 fdi:010005648 Navarro Elisabeth, Gauthier Daniel, Lesage G., Simonet P., Jaffré Tanguy, Rinaudo Gérard. Ecology and biodiversity of the symbiosis Frankia-Casuarinaceae in New Caledonia. In : . Deuxième conférence internationale sur l'écologie des milieux serpentiniques, Nouméa, 31 juillet-5 août 1995 : résumés = Second international conference on serpentine ecology, Noumea, july 31-august 5, 1995 : abstracts ORSTOM, 1995, 35 Ecologie des Milieux Serpentiniques : Conférence Internationale = Serpentine Ecology : International Conference, 2., Nouméa (NCL), 1995/07/31; 1995/08/05 EN NOUVELLE CALEDONIE