Co-entrapment of Trichoderma harzianum and Glomus sp. within alginate beads: impact on the arbuscular mycorrhizal fungi life cycle

Abstract

Aims: This study was performed to explore the compatibility and applicability of plant beneficial micro‐organisms (i.e. Trichoderma harzianum MUCL 29707 and Glomus sp. MUCL 41833) co‐entrapped in alginate beads. Methods and Results: Spores of Glomus sp. and conidia of T. harzianum were immobilized in alginate beads and the impacts of the saprotrophic fungi on the presymbiotic and symbiotic phase of the arbuscular mycorrhizal (AM) fungi evaluated under strict in vitro culture conditions. Our results demonstrated the capacity of both micro‐organisms in combination to regrowth outside the calcium alginate coating. The presence of T. harzianum did not hinder the AM fungal development but rather stimulated its spore production and fitness. Conclusions: The combination of T. harzianum MUCL 29707 with Glomus sp. MUCL 41833 in alginate beads may represent a reliable alternative inoculum formulation for application in sustainable agriculture. Significance and Impact of the Study: The entrapment in the alginate beads of two fungi (i.e. a saprotroph and a symbiont) having beneficial effects on plants represents a promising formulation for the development of inoculants adapted to field application.

Impact of plant growth-promoting rhizobacteria on root colonization potential and life cycle ofRhizophagus irregularisfollowing co-entrapment into alginate beads

“…For instance, De Jaeger et al . () and more recently Buysens et al . () co‐entrapped the AMF Rhizophagus irregularis MUCL 41833 with the fungus Trichoderma harzianum MUCL 29707 into alginate beads for field trials, which resulted in an increased potato yield (Buysens et al .…”

“…Entrapment also allows an easy delivery of the microbial inoculants at the site where they are needed and can be used in seed drills commonly used by farmers (De Jaeger et al . ). Entrapment in alginate has been reported in numerous studies with single isolated micro‐organisms (e.g.…”

“…More recently, De Jaeger et al . () succeeded in the co‐entrapment of R. irregularis MUCL 41833 with T. harzianum . They demonstrated that the %PIB of the AMF was not affected by the presence of T. harzianum .…”

“…Alginate beads can protect microbes from biotic and abiotic stresses and improve persistence and physiological activity as well as cell densities (Schoebitz et al 2013). Entrapment also allows an easy delivery of the microbial inoculants at the site where they are needed and can be used in seed drills commonly used by farmers (De Jaeger et al 2011). Entrapment in alginate has been reported in numerous studies with single isolated micro-organisms (e.g.…”

“…One germinated spore per bead was sufficient to consider the bead as potentially infective. More recently, De Jaeger et al (2011) succeeded in the co-entrapment of R. irregularis MUCL 41833 with T. harzianum. They demonstrated that the %PIB of the AMF was not affected by the presence of T. harzianum.…”