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

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

Formulations of Plant Growth-Promoting Microbes for Field Applications

Development of a plant growth-promoting (PGP) microbe needs several steps starting with isolation of a pure culture, screening of its PGP or antagonistic traits by means of different efficacy bioassays performed in vitro, in vivo or in trials under greenhouse and/or field conditions. In order to maximize the potential of an efficient PGP microbe, it is essential to optimize mass multiplication protocols that promote product quality and quantity and a product formulation that enhances bioactivity, preserves shelf life and aids product delivery. Selection of formulation is very crucial as it can determine the success or failure of a PGP microbe. A good carrier material should be able to deliver the right number of viable cells in good physiological conditions, easy to use and economically affordable by the farmers. Several carrier materials have been used in formulation that include peat, talc, charcoal, cellulose powder, farm yard manure, vermicompost and compost, lignite, bagasse and press mud. Each formulation has its advantages and disadvantages but the peat based carrier material is widely used in different part of the world. This chapter gives a comprehensive analysis of different formulations and the quality of inoculants available in the market, with a case study conducted in five-states of India

Development and field evaluation of liquid inoculants with native <i>Bradyrhizobial</i> 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.Keywords: Arachis hypogaea, Argentina, biological nitrogen fixatio