STUDY OF NATIVE BACILLUS THURINGIENSIS ISOLATES AND ANALYSIS OF ITS EFFECT ON SPODOPTERA LITURAA. MAHALAKSHMI, K. SUJATHA AND R. SHENBAGARATHAI
The control of Spodoptera litura is imperative to minimise severe damage they cause to diverse crops. It is possible to control Spodoptem by using the bacterium Bacillus thuringiensis that characteristically produces Insecticidal Crystal Proteins (ICPs). This paper describes the attempt of isolation of B. thuringiensis from Madurai soil samples and evaluation of its pathogenicity towards S. litum. The strains were named as B. thuringiensis LDC-1 to B. thuringiensis LDC-85. Among eighty five isolates of B. thuringiensis from seventy field soil samples, twelve isolates were selected for evaluation of toxicity against S. litura based on Colony and Parasporal inclusion morphology. The insecticidal activity of the selected twelve strains of B. thuringiensis from soil samples was assayed against second instar of Slitura larvae and scored only five active strains. After a second bioassay evaluation of the five active strains, one of the most potent strain B. thuringienis LDC-7 was selected for further characterization. The insecticidal activity of the effective strain B. thuringiensis LDC- 7 was similar to reference strain B. thuringiensis var. entomocidus towards S. littera. This isolate was further characterized biochemically and their results are in accordance with standard B. tIntringiensis var. entomocidus.
Enter your contact information below to receive full paper.