EFFECT OF BACTERIA ON GERMINATION OF ARBUSCULAR MYCORRIZAL FUNGI AND THEIR CO-INOCULATION ON PINEAPPLE SEEDLINGS

The effect of plant growth-promoting bacteria (PGPB) on spore germination of arbuscular mycorrizal fungi (AMF) and the co-inoculation of these organisms on aclimatization of micropropagated pineapple cv. Perola seedlings were evaluated. The germination study was performed in a completely randomized design (CRD), factorial of 3 (G. albida, G. etunicatum, S. heterogama) x 4 (C210, RAB9, ENF10 and control) with five replicates, in plate with water-agar, where the bacteria and spores were inoculated and evaluated after 21 and 28 days. The co-inoculation study was performed in a CRD, factorial of 5 (G. albida, G. etunicatum, S. heterogama, mixture of AMF and control) x 5 (C210, RAB9, ENF10, mixture of PGPB and control) and six replicates. At the 21(th) day RAB9 stimulated germination of G. albida in relation to the others PGPB; ENF10 stimulated the germination of G. etunicatum in relation to absence of bacteria, where the spores did not germinate; differences were not observed for S. heterogama. At the 28(th) day C210 inhibited the germination of G. albida. In both periods, G. albida showed higher germination rate. In absence of PGPB, G. albida improved growth more than G. etunicatum. The effect of G. albida on seedlings can be inhibited by C210 and by the bacterial mixture. It was confirmed that AMF germination can be stimulated or inhibited in presence of PGPB while the mycorrhizal symbiosis can be inhibited. In general co-inoculation of AMF and PGPB did not improve growth of pineapple cv. Perola during the aclimatization period until the 90(th) day.