Pineapple (Ananas comosus L. Merrill) in vitro propagation results in the production of a large quantity of healthy and homogeneous plantlets. Despite these advantages, the long time required for acclimatization makes this agricultural practice too costly. Growth acceleration of plantlets by inoculation with endophytic and epiphytic diazotrophic bacteria may be useful to reduce this period. The objectives of this study were to evaluate the potential of 20 diazotrophic bacteria strains in synthesizing indole, solubilizing Ca phosphate and Zn oxide and acting against the fungus Fusarium subglutinans f. sp. ananas, and subsequently, evaluate the performance of pineapple 'Vitória' propagated by tissue culture in response to the application of these isolates during the acclimatization period in a greenhouse. Shoot and root growth characteristics and leaf nutrient content of pineapple were evaluated. Results showed differences in the ability of the bacteria strains to synthesize indole, solubilize Ca phosphate and Zn oxide and act against Fusarium. Differences in the growth-promoting capacity of the shoot and root system of bacteria and leaf accumulation of N, P, K, Ca and Mg in pineapple were also shown. Inoculation with diazotrophic bacteria can promote the growth of plantlets during the acclimatization period, improving the adaptation of pineapple to the ex-vitro environment
Ananas comosus; tissue culture; diazotrophic bacteria; phosphate solubilizing bacteria; fusariose; auxin
