ABSTRACT
cryⅢ gene,they were found in 75 6%,67 9%,58 4% and14 5% of the strains respectively,no cryⅠ Ⅴ gene was found,10cry gene combination types were concluded.The Bt isolates which contained cryⅠ genes were further characterized by additional PCR detection with specific primers of the cryⅠAc,cryⅠC and cryⅠE genes.20 Bt isolates which contained cryⅠAc,cryⅠC,cryⅡ and cryⅤ genes were found,among them the strain Bt\|15A3 is high toxic to Heliothis armigera,Spodoptera exigua and Plutella xylostella,and has potential developing and applying value.
ABSTRACT
The effect of Ultraviolet (UV) rays on the activity of parasporal crystal of Bacillus thuringiensis, var. Kurstaki HD-1 strain was studied by SEM, SDS-PAGE, bioassay and other methods. It was found that the morphology and surface structure of PC were damaged ,and its solubility in alkaline solution or silkworm gut juice was decreased after being irradiated by UV, the solubility was lost completely after a long time irradiation over 5 hours, so the processed PC could not be degraded into protoxin with insecticidal activity and was denatured.