In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

489Suggestion and Future Plan1. Due to its multi-nutrients deficiency, further application of the rhizobiasymbiotic of this tree species should be integrated into other nutrientmanagements, for example by combining with arbuscular mycorrhizal fungi.This symbiotic association should be treated as one component, amongother component, that contributing to an integrated nutrient managementduring development of P.f. on ultisols.2. Strong evidences on genotypic interaction between rhizobial isolates andthe provenances/progenies of the P. falcataria cautions the practicalapplication of this associations. The host trees proven their site adaptability(using genetic trials) offer a suitable material for developing an improvedrhizobial component.3. More analytical studies on the field competitiveness traits of the promisingrhizobial isolates should be undertaken by using a reporter gene.4. Under-developed and early senescent root nodules in the several hostisolateinteractions suggesting an evidence of genotypic interaction thatmay attracting further studies on molecular mechanisms of these symbioticassociations.AcknowledgementsThis research was a part of Riset Unggulan Terpadu (RUT V) project entitled“Developing rhizobia and arbuscular mycorrhizal technology in Paraserianthesfalcataria for ultisols” financed by the National Research Council (DRN) ofIndonesia. The Tree Improvement group of Fac. of Forestry Gadjah MadaUniversity was sincerely thanked for providing the P.falcataria seeds collectedfrom various regions in Indonesia.ReferencesChan, C.L., Lumpkin, T.A., & Root, C.S. 1988. Characterisation of Bradyrhizobium sp. associatedwith Astragalus siniscus, L. using serological agglutination, intrinsic antibiotic resistance,plasmid visualization and field performance. Plant and Soil 109, 85-91.Fliss, S.E., Glenn, A.R., & Dilworth, M.J. 1993. The interaction between aluminium and rootnodule bacteria. Soil Biology and Biochemistry 25, 403-417.Galiana, A. & Pin, Y. 1996. The benefits of rhizobial inoculation in tropical forestry: response ofAcacia mangium to the application of selected strains of Bradyrhizobium spp. In: DieterM.J., Matheson, A.L., Nikles, D.G., Harwood, C.E. & Walkers, S.M. (eds.) Tree improvementfor sustainable tropical forestry. International symposium by QFRI-IUFRO, Coloundra.Gemell, L.G., Roughley, R.J., Reed, M.L. & Hartley, E.J. 1993. Screening of Rhizobiumleguminosarum bv. trifolii for adaptation to acid and neutralized soils using a selective agarmedium. Soil Biology and Biochemistry 25, 1463-1464.