Evaluation of interactions between an Arbuscular Mycorrhizal Fungus and a strain of Trichoderma sp. as potential bioinoculants

STATELLO, MARINA; COLOMBO, ROXANA; RODRIGUEZ, MARÍA ALEJANDRA; SILVANI, VANESA ANALÍA; RECCHI, MARINA; SCORZA, MARÍA VICTORIA; EN LO, TAI; GODEAS, ALICIA MARGARITA

San Carlos de Bariloche

Simposio; II International Symposium Mycorrhizal Symbiosis in South America.; 2019

Universidad Nacional del comahue

Microorganisms of soil can form consortium that enhance survival and fitness of the plant. Some fungi bring nutrients to its host, like the arbuscular mycorrhizal fungi (AMF), while others improve resistance to biotic or abiotic stress like Trichoderma harzianum. The aims of this work were to evaluate the interaction between the AMF strain GA5 and T. harzianum strain BF24 under in vitro and in vivo conditions, and to study the effect of the ?consortium? as bioinoculant on alfalfa (Medicago sativa). The in vitro system consisted on divided petri dishes with transformed carrot roots growing in MM at one side (RC) and sterile soil at the other side (SC), where only mycelia could access. The experimental design had four treatments: GA5, BF24, GA5+BF24, and control. GA5 was always inoculated at the RC, while BF24 was inoculated at SC. For the third treatment, BF24 was inoculated once hyphae of strain GA5 reached 50% of SC. After three days, glomalin-related soil proteins (GRSPs), BF24 colony-forming units (CFU), extraradical mycelium (ERM) and GA5 spores were measured. The in vivo test was carried out under semi-controlled conditions. Sterilized seeds were sown in pots with tyndallized substrate, and after one week, they were inoculated with 50 GA5 spores. After 30 days, plantlets were inoculated with 1,60E+07 CFU of BF24. Percentage of mycorrhization, GRSPs, soil enzymatic activity, MER, spores, CFU, green index of the leaves (SPAD) and biomass dry weight were registered. Under the in vitro system, the ERM development resulted significantly higher when co-inoculation of strains occurred. Spores of GA5 strain were only observed in presence of BF24, while CFU and MER were higher in presence of GA5. No significant differences in GRSPs concentration between treatments were observed. SPAD values were significantly different among control and treatments, and co-inoculated roots tended to present a greater mycorrhization. In conclusion, this consortium interacted by producing an enhance on hyphal development and spores/conidia production in both strains, and also showed positive effects on alfalfa, thus it could be considered as potential bioinoculant.