Motility and biofilm production involved in the interaction of phosphate solubilizing endophytic strains with peanut, maize and soybean plants

Endophytic plant growth promoting bacteria are of great interest since the ability to colonize the internal tissues of plants gives it an adaptive advantage. To confer any beneficial effect on the plant, bacteria must present a successful colonization and thus be competent in the rhizosphere and finally infect internal tissues. In this sense, bacterial motility is an essential property involved in plant-microorganism interaction where bacteria can colonize the root and at the same time form biofilms. Within plant beneficial bacteria those that present phosphate solubilizing activity are of great interest due to the contribution of phosphorus to plants. The objective of this work was to evaluate the motility and biofilm formation properties of the strains Serratia sp. S119 and Enterobacter sp. J49 growing in the presence of peanut, maize and soybean root exudates. Results obtained indicated that both strains have flagella, possess swimming, swarming and twitching motilities and showed differential chemotactic attraction against root exudates. In addition, the strains under study showed the ability to form biofilms, being this ability greater in minimal media, in which a greater decrease was also seen by the addition of root exudates in the first hours of growth. The changes produced by the addition of root exudates in the chemotaxis and biofilm formation of the strains suggests that compounds released by the plants are detected by these bacteria and could be part of the molecular dialogue involved in their interaction with the roots of plant.Fil: Lucero, Cinthia Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Lorda, Graciela Susana. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Departamento de Química; ArgentinaFil: Ludueña, Liliana Mercedes. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Anzuay, María Soledad. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Taurian, Tania. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; Argentin

Peanut Endophytic Phosphate Solubilizing Bacteria Increase Growth and P Content of Soybean and Maize Plants

Phosphorus (P) is a limiting factor of plant development due to its low availability in the soil. The use of endophytic phosphate solubilizing bacteria as a more sustainable alternative to the use of chemical phosphorus fertilizers is proposed in this study. The objectives were to analyze the effect of simple inoculations of native peanut endophytic phosphate solubilizing bacteria on plant growth promotion and P content of soybean and maize and to evaluate their survival and endophytic colonization capacity on these plants. In addition, bacterial plant cell wall degrading enzymes activities in presence or absence of root exudates was determined. Soybean, maize and peanut plants were grown on a microcosm scale and inoculated with Enterobacter sp. J49 or Serratia sp. S119. It was observed that phosphate solubilizing strains promoted the growth of maize and soybean plants and contributed significantly P to their tissues. A significant increase in the phosphate solubilizing capacity of the plant rhizosphere after the end of the assay was observed. The strains showed to survive in plant’s growth substrate and in the case of Enterobacter sp. J49, it showed also to colonize endophytically maize and soybean. Root exudates of the three plants showed to produce changes in pectinase and cellulase activities of the strains. The bacterial strains analyzed in this study constitutes potential sources for the formulation of biofertilizers for their application for several crops in agricultural soils with low P content.Fil: Lucero, Cinthia Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Lorda, Graciela Susana. Universidad Nacional de La Pampa; ArgentinaFil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Ludueña, Liliana Mercedes. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Taurian, Tania. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones Agrobiotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Agrobiotecnológicas; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentin

Efecto de inoculantes biológicos sobre la comunidad bacteriana rizosférica y el crecimiento de plantas de maní y maíz

Fil: Anzuay, María S. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina.Fil: Angelini, Jorge G. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina.Fil: Taurian, Tania. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina

Development and field evaluation of liquid inoculants with native Bradyrhizobial strains for peanut production

A critical process in the leguminous crops cycles is biological nitrogen fixation (BNF). Application of inoculants with N fixing bacteria is economically and environmentally favourable. The aim of this work was to select competitive native peanut microsymbionts, evaluate their survival in inoculant support and assess their impact on peanut (Arachis hypogaea L.) production under field conditions at Córdoba province in Argentina. The efficient N fixing Bradyrhizobium sp. J-81 and Bradyrhizobium sp. J-237, previously obtained from peanut nodules in the region of Cordoba, Argentina, were evaluated. In microcosm assays, plants inoculated with these isolates demonstrated better symbiotic parameters than those inoculated with reference strains. Different bacterial growth media and inoculant stabiliser solutions were evaluated. Balanced medium and arabic gum stabilising solution had optimal bacterial growth and the highest bacterial concentration and viability, respectively. Inoculation with either inoculants resulted in 44% greater peanut pod yield at Pizarro compared to the non-inoculated plants, although no significant differences were found with respect to commercial inoculants treatments.La fixation biologique de l’Azote (FBA) est un processus important dans le cycle de vie des légumineuses. L’application d’inoculum de bactéries fixatrices d’azote est favorable au double plan économique et environnemental. Le but de cette étude était de sélectionner des bactéries symbiotiques de l’arachide natives et compétitives, évaluer leur temps de survie dans support d’inoculum et évaluer leur impact sur la production en plein champ de l’arachide (Arachis hypogaea L.) dans la province de Córdoba en Argentine. Les bactéries fixatrices d’azote Bradyrhizobium sp. J-81 et Bradyrhizobium sp. J-237, extraites de nodules collectés sur des plants cultivés dans la région de Cordoba en Argentina, ont été évaluées. Dans des essais de microcosme, des plants inoculés avec ces isolats ont exhibés de meilleurs paramètres symbiotiques que les plants non inoculés. Différents média de culture bactérienne et supports inoculums ont été testés. Medium mixte et solution stabilisée à la gomme arabique ont respectivement exhibés la croissance optimale des bactéries et la meilleure conservation et viabilité des bactéries. L’application de n’importe quel inoculum produisit 44% plus de rendement en gousses d’arachides à Pizarro par rapport aux plantes non-inoculées, et ceci bien qu’aucune différence significative n’a été observée en comparaison avec les traitements à l’inoculum du commerce.Fil: Valetti, Lucio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Angelini, Jorge Guillermo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Taurian, Tania. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Ibañez, Fernando Julio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Muñoz, Vanina Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Anzuay, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; ArgentinaFil: Ludueña, Liliana Mercedes. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Fabra, Adriana Isidora. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Cambio en la diversidad de hongos micorrícicos arbusculares asociados a la planta del maní (Arachis hypogaea L.) luego de la aplicación de Agroquímicos

Actualmente se ha podido demostrar que los hongos micorrícicos arbusculares (HMA) están presentes formando parte de simbiosis con más del 80% de las plantas terrestres. El estudio de diversidad de especies en las comunidades de los HMA presenta serias dificultades debido a que no se conocen estadios de reproducción sexual, sus células ser multinucleadas y ser simbiontes obligados, por lo que en los estudios de biodiversidad es necesario llevar a cabo análisis basados en criterios morfológicos como el recuento e identificación de esporas, porcentaje de colonización, y criterios genéticos a través de análisis de variabilidad de las regiones ITS, SSU (18S) y LSU (28S) del ADN ribosomal.Argentina es uno de los principales países productores de maní en el mundo, concentrándose en la provincia de Córdoba la mayor producción manisera y su industrialización, lo que se considera una economía regional de mucha importancia. Considerando los efectos benéficos de las HMA en los cultivos de interés agronómico, el objetivo del trabajo fue estudiar los efectos de los agroquímicos sobre la biodiversidad de los HMA asociados a las raíces de las plantas de man

Biocontrol bacterial communities associated with diseased peanut (Arachis hypogaea L.) plants

In the present study, the isolation and characterization of endophytic and epiphytic biocontrol bacteria from peanut plants affected with white mold and root rot are described. Two hundred and sixty three isolates were selected from diseased plants and biocontrol traits analyzed were antibiosis against Sclerotinia minor and Fusarium solani, siderophore production and similarities in carbon source utilization between bacteria and fungi. Diversity and sequence analysis of potential biocontrol Bacteria were developed. It was observed that 34% of the 263 isolates were able to inhibit the growth of at least one of the two fungi tested and 47% showed siderophore production in CAS medium. Analysis of Nutritional similarity index demonstrated that both fungi were capable to growth in all carbon compounds assayed and that 20% of bacteria showed NOI values equal or above 0.9. Genetic diversity analysis by BOXePCR indicated that culturable epiphytic and endophytic bacteria associated with peanut are highly diverse. The 16S rDNA sequences of the most remarkable isolates, indicated as potential biocontrol agents according to all the screenings performed and belonging to different BOX profiles showed that they were 99% identical to Bacillus amyloliquefaciens. Comparisons analysis was performed with results previously obtained from a similar study done in the bacterial community isolated from healthy peanut plants from the same producing area. Results obtained suggest that presence of fungal pathogens in peanut ecosystem would be acting as a selective factor in the peanut plant associated bacterial communities. It was concluded from this study that peanut soils in Cordoba harbor bacteria with major biocontrol properties which represent a potential source of new strains that could be used as biological inoculants in agriculture. Published by Elsevier Masson SAS.Fil: Ludueña, Liliana Mercedes. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Taurian, Tania. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Tonelli, Maria Laura. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Angelini, Jorge Guillermo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Valetti, Lucio. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales. Departamento de Ciencias Naturales. Cátedra de Biologia General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Muñoz, Vanina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Fabra, Adriana Isidora. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Fisicoquímicas y Naturales. Departamento de Ciencias Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Native bacteria isolated from roots and rhizosphere of Solanum lycopersicum L. increase tomato seedling growth under a reduced fertilization regime

In semiarid regions is important to use native strains best adapted to these environments to optimize plant-PGPR interaction. We aimed to isolate and characterize PGPR from roots and rhizosphere of a tomato crop, as well as studying the effect of its inoculation on tomato seedlings growth. We selected four strains considering their effectiveness of fixing nitrogen, solubilizing phosphate, producing siderophores and indole acetic acid. They belong to the genera Enterobacter, Pseudomonas, Cellulosimicrobium, and Ochrobactrum. In addition, we also analyzed the ability to solubilize Ca3(PO4)2, FePO4 and AlPO4 and the presence of one of the genes encoding the cofactor PQQ in their genome. Enterobacter 64S1 and Pseudomonas 42P4 showed the highest phosphorus solubilizing activity and presence of pqqE gene. Furthermore, in a tomato-based bioassay in speed-bed demonstrated that a sole inoculation at seedling stage with the strains increased dry weight of roots (49–88%) and shoots (39–55%), stem height (8–13%) and diameter (5–8%) and leaf area (22–31%) and were equal or even higher than fertilization treatment. Leaf nitrogen and chlorophyll levels were also increased (50–80% and 26–33%) compared to control. These results suggest that Enterobacter 64S1 and Pseudomonas 42P4 can be used as bio-inoculant in order to realize a nutrient integrated management.Fil: Pérez Rodriguez, María Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Piccoli, Patricia Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Baraldi, Rita. Consiglio Nazionale delle Ricerche; ItaliaFil: Neri, Luisa. Consiglio Nazionale delle Ricerche; ItaliaFil: Taurian, Tania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Cuarto; ArgentinaFil: Lobato Ureche, Miguel Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Segura, Diana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Cohen, Ana Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentin

Role of bacterial pyrroloquinoline quinone in phosphate solubilizing ability and in plant growth promotion on strain <i>Serratia</i> sp. S119

The aim of this study was to analyze if cofactor pyrroquinoline quinone from Serratia sp. S119 is involved in the inorganic phosphate solubilization mechanism and in its ability to promote the plant growth. Site directed mutagenesis was performed to obtain a pqqE- minus mutant of strain Serratia sp. S119. The phosphate solubilization ability, gluconate and PQQ production of the mutant Serratia sp. RSL (pqqE-) was analyzed. Mutant RSL (pqqE-) showed significant decrease in P soluble and gluconic acid levels produced and undetectable levels of PQQ cofactor compared with wild-type strain. Complementation with synthetic PQQ cofactor restored P solubilization and gluconate production reaching the levels produced by wild-type strain. PqqE gene sequence indicated that it is highly conserved within Serratia strains and its product shows conserved motifs found in other PqqE proteins of several bacteria. The effect of the inoculation of the PQQ- mutant on peanut and maize plants was evaluated in pot assays. Plants growth parameters showed no differences among the different treatments indicating that PQQ from Serratia sp. S119 is not involved in the growth promotion of these plants. PQQ cofactor is essential for phosphate solubilization ability of Serratia sp. S119 but is not required for growth promotion of peanut and maize plants.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones Industriale

Development and field evaluation of liquid inoculants with native Bradyrhizobial strains for peanut production

A critical process in the leguminous crops cycles is biological nitrogen fixation (BNF). Application of inoculants with N fixing bacteria is economically and environmentally favourable. The aim of this work was to select competitive native peanut microsymbionts, evaluate their survival in inoculant support and assess their impact on peanut ( Arachis hypogaea L.) production under field conditions at C\uf3rdoba province in Argentina. The efficient N fixing Bradyrhizobium sp. J-81 and Bradyrhizobium sp. J-237, previously obtained from peanut nodules in the region of Cordoba, Argentina, were evaluated. In microcosm assays, plants inoculated with these isolates demonstrated better symbiotic parameters than those inoculated with reference strains. Different bacterial growth media and inoculant stabiliser solutions were evaluated. Balanced medium and arabic gum stabilising solution had optimal bacterial growth and the highest bacterial concentration and viability, respectively. Inoculation with either inoculants resulted in 44% greater peanut pod yield at Pizarro compared to the non-inoculated plants, although no significant differences were found with respect to commercial inoculants treatments.La fixation biologique de l\u2019Azote (FBA) est un processus important dans le cycle de vie des l\ue9gumineuses. L\u2019application d\u2019inoculum de bact\ue9ries fixatrices d\u2019azote est favorable au double plan \ue9conomique et environnemental. Le but de cette \ue9tude \ue9tait de s\ue9lectionner des bact\ue9ries symbiotiques de l\u2019arachide natives et comp\ue9titives, \ue9valuer leur temps de survie dans support d\u2019inoculum et \ue9valuer leur impact sur la production en plein champ de l\u2019arachide ( Arachis hypogaea L.) dans la province de C\uf3rdoba en Argentine. Les bact\ue9ries fixatrices d\u2019azote Bradyrhizobium sp. J-81 et Bradyrhizobium sp. J-237, extraites de nodules collect\ue9s sur des plants cultiv\ue9s dans la r\ue9gion de Cordoba en Argentina, ont \ue9t\ue9 \ue9valu\ue9es. Dans des essais de microcosme, des plants inocul\ue9s avec ces isolats ont exhib\ue9s de meilleurs param\ue8tres symbiotiques que les plants non inocul\ue9s. Diff\ue9rents m\ue9dia de culture bact\ue9rienne et supports inoculums ont \ue9t\ue9 test\ue9s. Medium mixte et solution stabilis\ue9e \ue0 la gomme arabique ont respectivement exhib\ue9s la croissance optimale des bact\ue9ries et la meilleure conservation et viabilit\ue9 des bact\ue9ries. L\u2019application de n\u2019importe quel inoculum produisit 44% plus de rendement en gousses d\u2019arachides \ue0 Pizarro par rapport aux plantes non-inocul\ue9es, et ceci bien qu\u2019aucune diff\ue9rence significative n\u2019a \ue9t\ue9 observ\ue9e en comparaison avec les traitements \ue0 l\u2019inoculum du commerce

Scientific Opinion addressing the state of the science on risk assessment of plant protection products for in-soil organisms

Following a request from EFSA, the Panel on Plant Protection Products and their Residues developed an opinion on the science behind the risk assessment of plant protection products for in-soil organisms. The current risk assessment scheme is reviewed, taking into account new regulatory frameworks and scientific developments. Proposals are made for specific protection goals for in-soil organisms being key drivers for relevant ecosystem services in agricultural landscapes such as nutrient cycling, soil structure, pest control and biodiversity. Considering the time-scales and biological processes related to the dispersal of the majority of in-soil organisms compared to terrestrial non-target arthropods living above soil, the Panel proposes that in-soil environmental risk assessments are made at in- and off-field scale considering field boundary levels. A new testing strategy which takes into account the relevant exposure routes for in-soil organisms and the potential direct and indirect effects is proposed. In order to address species recovery and long-term impacts of PPPs, the use of population models is also proposed