[Objective] This study aimed to investigate the biological characteristics of a Bacillus thuringiensis strain YNI-1, which has high virulence to Lepidoptera spp. [Method] The crystal protein of YNI-1 was analyzed by S...[Objective] This study aimed to investigate the biological characteristics of a Bacillus thuringiensis strain YNI-1, which has high virulence to Lepidoptera spp. [Method] The crystal protein of YNI-1 was analyzed by SDS-PAGE, and its indoor and field efficacy for Lepidoptera spp. was investigated. [Result] The parasporal crystal of YNI-1 has a diamond-like structure. The molecular weight of the original toxin protein is 136 kDa. After trypsin treatment, the original toxin protein was hy- drolyzed into active toxin protein with molecular weight of 63 kDa. For Plutella xy- Iostella and Pieris rapae, the indoor efficacy of B. thuringiensis was better than that of commercial B. thuringiensis （WP）. In view of field efficacy, rate of YNI-1 strain was higher than that of commercial B [Conelusion] YNI-1 strain has excellent development potential. the insects reduced thuringiensis （WP）.展开更多
Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis...Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis medinalis （Guenee） at 48 HAT and 72 HAT. Bioassay results depicted CrylAa was the most toxic （LCso 2.35 ppm） followed by CrylBa （LCso 8,50 ppm） and CrylAb （LCso 8.73 ppm） at 48 HAT, whereas, at 72 HAT CrylAb proved to be highly toxic （LC50 0.50 ppm） followed by CrylAa （LCso 4.07 ppm）, CrylAc （LCso 4,84 ppm） and CrylBa （LCso 6.42 ppm）. Toxins Cry2Aa, CrylCa, CrylDa and CrylEa did not resulted in any mortality at 48 HAT and 72 HAT, respectively. Baseline estimates for CrylAb against 1st instar larvae of C. medinalis sampled from seven geographical locations revealed variation in LC50＇s from 0.37 ppm to LC50 16.25 ppm at 48 HAT and LC50 0.50 ppm to LC50 6.49 ppm 72 HAT, respectively with relative resistance ratios of 44-fold and 13-fold at 48 HAT and 72 HAT over the susceptible population.展开更多
基金Supported by Natural Science Foundation of Yanbian University(2011-34)~~
文摘[Objective] This study aimed to investigate the biological characteristics of a Bacillus thuringiensis strain YNI-1, which has high virulence to Lepidoptera spp. [Method] The crystal protein of YNI-1 was analyzed by SDS-PAGE, and its indoor and field efficacy for Lepidoptera spp. was investigated. [Result] The parasporal crystal of YNI-1 has a diamond-like structure. The molecular weight of the original toxin protein is 136 kDa. After trypsin treatment, the original toxin protein was hy- drolyzed into active toxin protein with molecular weight of 63 kDa. For Plutella xy- Iostella and Pieris rapae, the indoor efficacy of B. thuringiensis was better than that of commercial B. thuringiensis （WP）. In view of field efficacy, rate of YNI-1 strain was higher than that of commercial B [Conelusion] YNI-1 strain has excellent development potential. the insects reduced thuringiensis （WP）.
文摘Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis medinalis （Guenee） at 48 HAT and 72 HAT. Bioassay results depicted CrylAa was the most toxic （LCso 2.35 ppm） followed by CrylBa （LCso 8,50 ppm） and CrylAb （LCso 8.73 ppm） at 48 HAT, whereas, at 72 HAT CrylAb proved to be highly toxic （LC50 0.50 ppm） followed by CrylAa （LCso 4.07 ppm）, CrylAc （LCso 4,84 ppm） and CrylBa （LCso 6.42 ppm）. Toxins Cry2Aa, CrylCa, CrylDa and CrylEa did not resulted in any mortality at 48 HAT and 72 HAT, respectively. Baseline estimates for CrylAb against 1st instar larvae of C. medinalis sampled from seven geographical locations revealed variation in LC50＇s from 0.37 ppm to LC50 16.25 ppm at 48 HAT and LC50 0.50 ppm to LC50 6.49 ppm 72 HAT, respectively with relative resistance ratios of 44-fold and 13-fold at 48 HAT and 72 HAT over the susceptible population.
