ABSTRACT
Abstract Plant growth-promoting rhizobacteria strains from special formulations have been used to optimize eucalyptus cutting production. To undertake quality control for the formulated products, the rhizobacterial strains should be characterized to assess their purity and authentication. In the present study, we characterized nine strains of rhizobacteria, including three Bacillus subtilis (S1, S2 and 3918), two Pseudomonas sp. (MF4 and FL2), P. putida (MF2), P. fulva (Ca), Frateuria aurantia (R1), and Stenotrophomonas maltophilia (CIIb). The strains were differentiated by colony morphology after 24 h of incubation in three different solid state culture media (glucose-nutritive agar, 523 medium and yeast extract-mannitol agar), sensitivity to a panel of 28 antibiotics (expressed according to the formation of inhibition halos of bacterial growth in the presence of antibiotics), and PCR-RFLP profiles of the 16S rDNA gene produced using nine restriction enzymes. It was possible to differentiate all nine strains of rhizobacteria using their morphological characteristics and sensitivity to antibiotics. The molecular analysis allowed us to separate the strains CIIb, FL2 and R1 from the strains belonging to the genera Bacillus and Pseudomonas. By using these three methods concomitantly, we were able to determine strain purity and perform the authentication.
Subject(s)
Bacteria , Eucalyptus/growth & development , Eucalyptus/microbiology , Rhizosphere , Bacteria/classification , Bacteria/growth & development , Bacteria/drug effects , Bacteria/genetics , Polymorphism, Restriction Fragment Length , RNA, Ribosomal, 16S/genetics , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacologyABSTRACT
O objetivo do presente trabalho foi avaliar os efeitos dos danos causados por Heilipodus naevulus Mann. (Coleoptera: Curculionidae) no desenvolvimento de plantios jovens de eucalipto, além de relatar, pela primeira vez, a ocorrência desse inseto no estado do Espírito Santo. O período crítico para ocorrência foi caracterizado entre outubro a dezembro, de acordo com o regime de chuvas. Os danos causados pela praga reduziram o desenvolvimento e a qualidade das árvores de eucalipto.
This research aimed to evaluate the effects of damages caused by Heilipodus naevulus Mann. (Coleoptera: Curculionidae) to the development of eucalyptus young plantation, and to record, for the first time, the occurrence on Espírito Santo State, Brazil. The critical period of occurrence was observed between October to December according with rain regime. The damages caused by the pest reduced the development and quality of eucalyptus trees.
ABSTRACT
Este trabalho objetivou relatar, pela primeira vez, o ataque de um besouro podador em plantios de clones híbridos de eucalipto (Eucalyptus urophylla vs. E. grandis), localizados nos Estados da Bahia e do Espírito Santo. A espécie foi determinada como sendo Chalcodermus bicolor Fiedler, 1936 (Curculionidae: Molytinae). A fêmea poda os ponteiros e constrói um pequeno orifício onde deposita um único ovo, logo abaixo do ponto de incisão. O eucalipto é o primeiro hospedeiro relatado para esta espécie de besouro.
This research aimed to record, for the first time, the damage caused by a pruner beetle on hybrid eucalypts cloned trees (Eucalyptus urophylla vs. E. grandis), located in Bahia and Espírito Santo States, Brazil. The specie was determined as Chalcodermus bicolor Fiedler, 1936 (Curculionidae: Molytinae). The female prunes the tree shoot and lays a single egg inside a small hole, just below the incision point. Eucalypt is the first host recorded to this pruner beetle specie.
ABSTRACT
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 26-28°C. After 35 days, rooting percentage and dry root matter of cuttings were evaluated. Ten isolates capable of providing gains of up to 110 percent in root formation and up to 250 percent 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.
Neste trabalho, testaram-se 107 rizobactérias, isoladas da rizosfera de mudas de clones de eucalipto, quanto ao seu potencial como promotoras de enraizamento de estacas e miniestacas de eucalipto, em substrato à base de casca de arroz carbonizada e vermiculita (1:1). Estacas e miniestacas foram plantadas em tubetes cônicos contendo substrato tratado e não tratado (testemunha) e foram mantidas sob nebulização intermitente de água a 26-28°C. Aos 35 dias, avaliou-se a porcentagem média de estacas enraizadas e a massa seca do sistema radicular. Dez isolados destacaram-se como indutores de enraizamento e crescimento, propiciando ganhos de até 110 por cento e de 250 por cento, respectivamente. Esses isolados também foram eficientes no enraizamento de miniestacas, cujos ganhos variaram de acordo com o clone e isolado testado. Os maiores incrementos obtidos no enraizamento de estacas foram superiores aos observados para miniestacas. Em geral, quanto menor o índice de enraizamento do clone, maior foi o ganho médio obtido com a inoculação. Apenas os isolados 3918 (código R98) e MF4 (código R87) foram capazes de produzir ácido indol-acético (AIA) in vitro, em quantidades equivalentes a 0,7 e 0,67 µg/ml de suspensão, respectivamente. Quando comparados ao tratamento de miniestacas em ácido indol butírico (AIB), estes isolados promoveram incrementos significativos na porcentagem de enraizamento e na massa seca do sistema radicular de miniestacas.