Mycorrhiza, rhizobacteria, potato, bioinoculant
The aim of the present study was to test the feasibility of using the
encapsulation in alginate beads of different rhizobacteria strains with invitro
produced spores of the Mycorrhizal Fungi: Rhizophagus irregularis; and
evaluate the effects of bacteria on the symbiotic and symbiotic development
of the fungal partner.
Several bacterial strains were isolated and identified from 4 field plots in
Ecuador. However, for the in-vitro tests only bacteria belonging to the
Firmicutes group were selected due to their capacity to produce resistant
spores. In total 30 strains were tested for antagonism against Phytophtora
infestans and Rhizoctonia solani and their capacity to produce IAA
(indolacetic acid), P solubilization and ACC deaminase capacity. Further,
only ten bacterial strains were selected for the encapsulation with isolated
spores of the AMF Rhizophagus irregularis MUCL41833. The results showed
that one of these rhizobacteria strains identified as Paenibacillus sp (R47065)
had a positive effect on asymbiotic development of R. irregularis spores
(p<0.001).
Afterwards, alginate beads containing propagules of R. irregularis and
Paenibacillus sp. (R47065) were inoculated in close contact with the roots of
three potato varieties (I-Fripapa, Bintjie and Unica) growing under
autotrophic in-vitro systems. The results showed significant positive effects
of the bacteria in the performance of R. irregularis, associated to the potato
plants for most of the evaluated parameters.