Lilian Botelho Praca , Ana Cristina Meneses Mendes Gomes , Glaucia Cabral , Erica Soares Martins , Edison Hyoiti Sujii , Rose Gomes Monnerat

Embrapa Recursos Geneticose Biotecnologia, Parque Estacao Biologica - PqEB - Av. W5 Norte (final)Caixa Postal 02372, 70770-917, Brasaa­lia, DF, Brasil
Embrapa Recursos Geneticose Biotecnologia, Parque Estacao Biologica - PqEB - Av. W5 Norte (final)Caixa Postal 02372, 70770-917, Brasaa­lia, DF, Brasil
Author    Correspondence author
Bt Research, 2012, Vol. 3, No. 3   doi: 10.5376/bt.2012.03.0003
Received: 07 May, 2012    Accepted: 14 May, 2012    Published: 22 May, 2012

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Praça et al., 2012, Endophytic Colonization by Brazilian Strains of Bacillus thuringiensis on Cabbage Seedlings Grown in Vitro, Bt Research, Vol.3, No.3 11-19 (doi: 10.5376/bt.2012.03.0003)

Bacillus thuringiensis is a very important bacterium used as a biological control agent of agricultural pests. It may be isolated from soil, water, plants and dead insects. Three Brazilian B. thuringiensis strains that present high activity to Lepidoptera pests were inoculated in the seeds of cabbage in order to study the penetration and endophytic colonization of this entomopathogen in cabbage using scanning electron microscopy. The ability of B. thuringiensis to colonize endophytic seedlings was verified by the presence of vegetative cells, spores and crystals of the four Brazilian B. thuringiensis strains in different parts of cabbage seedlings. The observation of B. thuringiensis structure on roots, shoots and leaves of cabbage revealed colonization predominantly on roots. The colonization was shown on the surface, near the stomata and inside stomata pores. The mechanism of penetration of B. thuringiensis probably occurs through openings and injuries in roots and then moves through the xylem until reaching the leaves. The endophytic colonization of B. thuringiensis did not affect the germination of seeds and initial seedling development. The strains labeled with radioisotopes were inoculated on cabbage and were detected inside the plant. This article demonstrates for the first time the ability of B. thuringiensis to colonize cabbage seedlings that are important to control the cryptic pest as P. xylostella and others endophytic insect’s pests. 
 

Bacillus thuringiensis; Colonization; Cabbage; Strains; Insecticidal activity