The occurrence of antagonistic bacteria in Glomus mosseae pot cultures

Biological control of root diseases, carried out by the manipulation of resident microbes or by the introduction of antagonists, should take into account the role played by mycorrhizal fungi in the mycorrhizosphere. In this work we have detected many antagonistic bacteria within the different zones of the mycorrhizosphere of the arbuscular mycorrhizal (AM) fungus Glomus mosseae, grown for 17 years in pot cultures. The selected bacteria were actively antagonistic against in vitro mycelial growth of species of the soil-borne pathogens Fusarium and Phytophthora and on the germination and germ tube growth of Phytophthora parasitica zoospores. These results are evidence of the mycorrhizal compatibility of the antagonistic bacteria isolated from the mycorrhizosphere and suggest the possibility of using AM fungi as vehicles of selected microorganisms in biological control of soil-borne pathogens.Présence de bactéries antagonistes dans les cultures de Glomus mosseae en pot. Le contrôle biologique des maladies des racines obtenues par la manipulation de microbes présents autour des racines ou par l'introduction d'antagonistes doit prendre en considération le rôle que les champignons mycorhizogènes peuvent jouer. Dans ce travail, nous avons détecté plusieurs bactéries antagonistes dans différentes zones de la mycorhizosphère du champignon mycorhizogène Glomus mosseae, élevé pendant 17 ans en pot. Les bactéries sélectionnées sont des antagonistes très actifs vis-à-vis de la croissance in vitro de champignons pathogènes telluriques tels que des Fusarium et des Phytophthora et de la germination et la croissance de tubes germinatifs de zoospores de Phytophthora parasitica. Ces résultats montrent une compatibilité entre les bactéries antagonistes isolés de la mycorhizosphère et les champignons mycorhizogènes à arbuscules et suggèrent la possibilité d'utiliser ces derniers comme un moyen de propagation de microorganismes sélectionnés pour le contrôle biologique de pathogènes telluriques

Molecular and functional characterization of beneficial bacteria associated with AMF spores

In the years to come, a major challenge for agriculture will be the implementation of sustainable intensification of agricultural practice, to ensure sufficient food production for the growing global population and to reduce chemical and energy inputs. This aim may be pursued by promoting the efficient use of beneficial soil microorganisms that play fundamental roles in plant growth and health. Among them, arbuscular mycorrhizal fungi (AMF), and their associated microbiota, can be considered biofertilizers, bioenhancers, and biocontrol agents, showing diverse plant growth-promoting (PGP) properties. Here we focus on approaches for the study of the identity and function of bacteria associated with AMF spores, referred to as spore-associated bacteria (SAB). Culture-independent methods are essential for the identification of their diversity; however, only culture-dependent approaches allow the determination of SAB functional roles, and the selection of the best performing strains, to be tested in laboratory experiments, as well as in the field. The discovery of SAB functional activities, e.g., phosphate solubilization and nitrogen fixation, as well as production of phytohormones, siderophores, and antibiotics, is opening new avenues for their targeted management in agriculture. In this chapter the approaches, techniques, and results relevant to culture independent and culture-dependent studies on beneficial SAB will be reviewed. Significant case studies dealing with SAB utilization as inoculants in experimental trials will be discussed, with the aim of prospecting their utilization, individually or in specially designed multifunctional consortia, in sustainable and innovative food production systems

Biotic interactions between saproxylic insect species

Biotic interactions between saproxylic insect specie