Growth-promoting potential of bacterial biomassin the banana micropropagated plants/Potencial da biomassa bacteriana promotora de crescimento no desenvolvimento de mudas micropropagadas de bananeira

• Published in: Revista brasileira de engenharia agrícola e ambiental 2018-11, Vol.22 (11), p.782
• Main Authors: da Silva, Christiana de F.B, de Brito, Thais L, Taniguchi, Carlos A.K, Lopes, Larissa A, Pinto, Gustavo A.S, de Carvalho, Ana C.P.P
• Format: Article
• Language: English
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v22n11p782-787

In the banana production system, a sustainable alternative for producing quality plantlets would be inoculation with plant growth-promoting bacteria (PGPB). Therefore, this study aimed to evaluate the growth-promoting potential of a bacterial biomass in micropropagated banana plantlets cultivar Prata Catarina, and to identify the mechanisms involved in plantmicroorganism interactions. In vitro, the biochemical assays tested were the solubilisation of phosphates, production of enzymes, production of ammonia, siderophores, and indole acetic acid. In the in vivo tests, the plants were bacterised ([10.sup.9]CFU [mL.sup.-1]) in two phases: acclimatisation, and cultivation in plastic bags. The design was a randomised block with 9 and 7 repetitions per treatment, which were: T1: control; T2: plants treated with isolate E2 (Bacillus pumilus group); T3: plants treated with RAB9 isolate (B. pumilus) for each phase. Bacterial isolates were capable of producing cellulases, amylases, pectinases, lipases, proteases, and siderophores. The plants gained in height, root length, root dry mass, pseudostem diameter, and leaf area. It is concluded that the PGPB can promote the growth of micropropagated banana plantlets through the production of enzymes and siderophores.Key words:Bacillus spp.Musa spp.plant growth-promotingrhizobacteriaNa bananicultura, uma alternativa sustentavel para producao de mudas de qualidade seria a inoculacao com as bacterias promotoras de crescimento de plantas (BPCP). Portanto, objetivou-se avaliar o potencial da biomassa bacteriana promotora de crescimento em mudas micropropagadas de bananeira cultivar Prata Catarina e identificar quais os mecanismos envolvidos nas interacoes planta/microrganismo. As provas bioquimicas testadas in vitro foram solubilizacao de fosfatos, producao de enzimas, producao de amonia, sideroforos e acido indolacetico. Nos ensaios in vivo, as plantas foram bacterizadas ([10.sup.9]UFC [mL.sup.-1]) em duas fases: na aclimatizacao e no cultivo em sacos plasticos. O delineamento experimental foi em blocos casualizados, com 9 e 7 repeticoes, por tratamento, dos quais foram: T1: controle; T2: plantas tratadas com isolado E2 (Bacilluspumilus group); T3: plantas tratadas com isolado RAB9 (B. pumilus), para cada uma das fases. Os isolados bacterianos foram capazes de produzir celulases, amilases, pectinases, lipases, proteases e sideroforos. Foram observadas nas mudas ganhos em altura, comprimento da raiz, massa seca da raiz, diametro