Rhizobacterial promotion of eucalypt rooting and growth

• Autor(a) principal: Teixeira,Débora A.
• Data de Publicação: 2007
• Outros Autores: Alfenas,Acelino Couto, Mafia,Reginaldo Gonçalves, Ferreira,Eraclides M., Siqueira,Leandro de, Maffia,Luiz A., Mounteer,Ann H.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Microbiology
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822007000100025
• topic: Eucalyptus; cloning; mini-cutting; cutting; rhizobacteria

A total of 107 rhizobacterial isolates, obtained from the rhizosphere of eucalypt clones were tested as rooting inducers of cuttings and mini-cuttings planted in substrate composed of carbonized rice husk and vermiculite (1:1). Cuttings and mini-cuttings were planted in conical plastic tubes containing treated and untreated (control) substrate and kept under intermittent mist irrigation at 26-28ºC. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110% in root formation and up to 250% in root biomass over non-inoculated control cuttings were selected. Gains in rooting varied according to clone and isolate tested. The greatest gains were obtained for the mini-cuttings exhibiting the lowest rooting efficiency. Among the ten isolates tested, only 3918 (code R98) and MF4 (code R87), produced 3-indole-acetic acid in vitro, at concentrations of 0.7 and 0.67 µg ml-1, respectively. Significant increases in rooting and root dry matter of cuttings grown on rhizobacteria-inoculated substrate were found when compared to untreated or indole-butyric acid (IBA) treated mini-cuttings.