Supressão de Meloidogyne javanica e promoção de crescimento da soja por linhagens de Bacillus thuringiensis

Abstract

A soja é um dos produtos mais produzidos e exportados pelo Brasil, porém apresenta elevadas perdas devido aos nematoides. Os nematoides de galha (Meloidogyne javanica e M. incognita) estão entre as principais espécies que causam danos econômicos na cultura e apresentam difícil controle. Este trabalho teve como objetivo identificar o potencial de 43 cepas de Bacillus thuringiensis no controle de Meloidogyne javanica e no desenvolvimento vegetativo da soja. O experimento foi conduzido em um delineamento inteiramente casualizado com 10 repetições em casa de vegetação. Foram avaliadas altura, massa fresca das partes aéreas e raízes, número de vagens, número de nematoides totais nas raízes, fator de reprodução e número de nematoides por grama de raízes. O potencial nematicida foi encontrado nas linhagens B. thuringiensis pakistani T13 001, B. thuringiensis morrisoni T08 001, B. thuringiensis Galleriae T05 001, B. thuringiensis suB. thuringiensisoxicus T06 001, B. thuringiensis shandogiensis T22 001, B. thuringiensis ostridial T08 A 001, B. thuringiensis londrina, B. thuringiensis kenyae T04 A001 e B. thuringiensis sumiyoshiensis e as linhagens B. thuringiensis tochigiensis, B. thuringiensis canadensis, B. thuringiensis sotto T04 001, B. thuringiensis tohokuensis, B. thuringiensis tenebrionis, B. thuringiensis finitimus T02 001, B. thuringiensis kurstaki (HD1), B. thuringiensis morrisoni T08 001, B. thuringiensis toumanoffi T11 001, B. thuringiensis neoleonensis T24 001, B. thuringiensis silo T26 001, B. thuringiensis entomocidus T06 A 001, B. thuringiensis kurstaki (HD73), B. thuringiensis kenyae VIII T04 A001, B. thuringiensis toyamensis e B. thuringiensis yunnanensis T20 001 promoveram maior desenvolvimento da soja comparado à testemunha. O isolado B. thuringiensis morrisoni T08 001 destacou-se em reduzir em 30% o número total de nematoides e em apresentar 21% a mais de vagens na soja quando comparado a testemunha.

Soybean is one of the most produced and exported products in Brazil, but it has high losses due to nematodes. Root-knot nematodes (Meloidogyne javanica and M. incognita) are difficult to control and they are among the main species that cause economic damage to crops. This work aimed to identify the potential of 43 strains of Bacillus thuringiensis in the control of Meloidogyne javanica and the soybean vegetative growth. The experiment was conducted in a completely randomized design with 10 replications in a greenhouse. Height, fresh mass of shoots and roots, reproduction factor, total number of nematodes in the roots, number of nematodes per gram of roots and number of pods were evaluated. The presence of nematicidal potential was found in strains B. thuringiensis pakistani T13 001, B. thuringiensis morrisoni T08 001, B. thuringiensis galleriae T05 001, B. thuringiensis suB. thuringiensisoxicus T06 001, B. thuringiensis shandogiensis T22 001, B. thuringiensis ostridial T08 A 001, B. thuringiensis londrina, B. thuringiensis kenyae T04 A001 and B. thuringiensis sumiyoshiensis and strains B. thuringiensis tochigiensis, B. thuringiensis canadensis, B. thuringiensis sotto T04 001, B. thuringiensis tohokuensis, B. thuringiensis tenebrionis, B. thuringiensis finitimus T02 001, B. thuringiensis kurstaki (HD1), B. thuringiensis morrisoni T08 001, B. thuringiensis toumanoffi T11 001, B. thuringiensis neoleonensis T24 001, B. thuringiensis silo T26 001, B. thuringiensis entomocidus T06 A 001, B. thuringiensis kurstaki (HD73), B. thuringiensis kenyae T04 A001, B. thuringiensis toyamensis and B. thuringiensis yunnanensis T20 001 promoted greater soybean development compared to the control. The strain B. thuringiensis morrisoni T08 001 stood out in reducing the total number of nematode by 30% and in presenting 21% more pods in soybean when compared to the control.