[Study on the test and evaluation of the toxicity of the strains preparation of the different subspecies of Bacillus thuringiensis and on the research into its standardization].
In this paper using the preparation of Bacillus thuringiensis of USA standard sample-subsp. kurstaki HD-1-S-1980 (H3a3b) the toxicity to different subspecies preparations such as subsp. dendrolimus U strain(H4a4b), subsp. galleriae C88 strain (H5a5b) is tested and evaluated. And product's standardization is also researched. Comparing their toxicity to various test-insects between the standard sample prepared from U strain and USA, standard sample, the boilogical determined results are as follows: the toxicity of U strain standard sample is respectively 18666.6 IU/mg(test-insects: Dendrolimus punctatus, 2nd larva), 22956.5 IU/mg(test-insects: Plutella kylostella, 2nd larva). The above-mentioned toxicity evaluations are higher than that of 16000 IU/mg of USA standard sample. The comparison in susceptibility shows as follows: suscepticibility of plutella kylostella is stronger than that of Dendrolimus punctatus. The products from U strain and C88 strain are trial-produced in medium-scale. The product's toxicity to test-insect Dendrolimus punctatus is determined using USA standard sample. The results are obtained as follows the toxicity evaluation of U strain products is 36444.4 IU/mg; that of C88 strain products is 28521.7 IU/mg. The both are obviously higher than that of USA standard sample. This proves that different subspecies strain's toxicity to the same test-insect is with defference and it is an important way to raise product's toxicity by improving and optimizing process in production. The whole experiment shows it is feasible to rectify the evaluation of the toxicity of our country's present products using USA standard sample, Dendrolimus punctatus and Plutella kylostella as test-insets. And it is simple and convienient as well as save time and save effort to make statistical analysis in computer with Basic program. To do statistical and operational analysis using our designed basic programming by micro-computer is more accurate and repid than by caculator.
Li
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Institute of Subtropical Forestry Chinese Academy of Forestry, Fuyang.
Zhao
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L
Wu
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T
D000818:Animals; D001413:Bacillus thuringiensis / Q000145:classification / Q000472:pathogenicity*; D009036:Moths; D010572:Pest Control, Biological; D012703:Serotyping; D013045:Species Specificity; D014774:Virulence