|
KMID : 1041219860280010043
|
|
Journal of Sericultural and Entomological Science
1986 Volume.28 No. 1 p.43 ~ p.53
|
|
|
Selection of Low Pathogenic Variety in Bacillus thuringiensis to Silkworm, Bombyx mori
|
|
|
|
|
Abstract
|
|
|
Among many microbial pesticides, Bacillus thuringiensis is one of the most hopeful pesticide and some commercial products have been appearing on the market.
Because these commercial products contain living spores and toxins of the organism, there is a danger that living spores of B. thuringiensis may be scattered by wind and cause a great damage in the sericulture areas.
In order to avoide these risks it is desirable to select the strain which has low pathogenicity to the silkworm, and at the sametime being highly pathogenic to the pest insects.
Thus this study has been carried out to acquire some basic informations about the procedure of desirable strain selection.
Three strains of B.thuringiensis var. kurstaki, var. dendrolimus and var. aizawai were used for the pathogenicity test on the silkworm, Bombyx mori and the fall webwarm, Iiyphantria cunea.
Those strains were investigated by the agarose gel electrophoresis patterns of Plasmid DNA determine whether mutation had occured.
Pathogenicity tests were carried out of using isolated crystal proteins and spore-crystal protein to mixtures of each strain, seperatively.
In case of using spore-crystal protein mixture, the order of pathogenicity in varities of B. thuringiensis against B. mori and H. cunea were kurstaki, aizawai, dendrolimus and kurstaki, dendrolimus, aizawai, respectively.
But using isolated crystal proteins, dendrolimus had the highest toxicity to H. cunea and the lowest toxicity to B. mori among tested three strains. From the above results, dendrolimus was presumed the most desirable strain for using microbial pesticide.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|