| Gypsy moth populations belong to Asian gypsy moth in China(AGM), Male and female adult have ability to fly, strong of Communication ability, caused great harms of Asian gypsy moth. This requires domestic related prevention, quarantine institutions and scientific research organizations to strengthen the prevention and control of gypsy moth moth, looking for more ecological and effective prevention and treatment methods. We through the LdNPV mixed with Bt, and the screening of LdNPV virulence strains to improve the karyotype of gypsy moth polygonal body the pathogenicity of the virus. And studied at home and abroad different strains strains on the pathogenicity of gypsy moth larvae in different regions of the differences, Compared the enhancinl (El), UDP-glucose enzyme genes (egt) and apoptosis suppressor iap-3of five strains LdNPV differences between the nucleotide and amino acid sequence, Provide theoretical reference for exploring LdNPV virulence genes of pathogenic, the study was the first time in China.Bt and LdNPV mixed results show that Bt diluted16000times liquid still has a synergisric effect on the virus,the synergism ratio of0.16times; Bt diluted8000times dilution liquid of viruses the synergism ratio was1.93times; Virus in concentration of2.5×107,2.5×106,2.5×105OBs/mL showed synergistic effect to Bt, the efficiency ratio of2.02,1.61,0.58times, respectively; While2.5×104OBs/mL and2.5×103OBs/mL virus solution to Bt showed additive and antagonism effect respectively. The wild mix when used, Set of cage experiment3different reagent processing mixed reagent insecticidal peak appeared in8d, below the4d Bt insecticides,higher than13d LdNPV pesticides. Average mortality rate of the mixed treatment of69.65percent is the highest.Shrubs spraying population density survey showed that mixed processing appeared two peaks were5d and16d respectively, Single dose of Bt and LdNPV processing were6d and18d respectively, the average population density reduction rate of the mixed processing was highest,38.67%, the mixed processing not only overcome the Bt on the persistent deficiencies, but also accelerated LdNPV insecticidal speed.We virulence screening of5kinds strains collected at home and abroad.Results show the Mongolia strains which we collected virulence works best,average LC50was47.86OBs/μL,the lowest value reached11.56OBs/μL, and LT50was16.38d, the lowest reaches10.28d, are all lower than other strains. Compared with domestic strains and abroad the strains LC50and LT50found that2strains of the domestic strain is superior to3strains of the United States and Canada,which may be related to experimental test insects for the local strains.Experiment,we also found that differentiation on the virulence of the strains had a significant effect on.There is a significant difference at virulence strains against the pathogenic of the test insects distribution in different regions. Of the5strains of the egt gene, E1gene and iap-3gene comparison results show that the five strains all had the three genes.Similarity comparison of the amino acid sequence of the three genes found that, the egt-N and E1-N were the emergence of a larger change, similarity lowest compared to other strains. Compared with NCBI sequence, egt-N has153amino acid changes and4amino acids insert and lack of5amino acids; E1-N has26positions of the amino acid change and the two amino acids insert; iap-3showed no bigger difference with the other strains.This with our test results LdNPV-N pathogenic strongest’s results is consistent. Homology tree figure shows, egt-N with other strains of low homology. And iap-s showed homology with other strains a little far, with E1-N higher homology.And the homology between the foreign strains is higher than the domestic strains. It also indicates that the strains appear differentiation within the geographical area, domestic strains and foreign strains exist differences of homology, this difference is also consistent with the gypsy moth geographical provenance.Through our research, we think LdNPV with Bt with proper proportion can not only improve the effectiveness of toxic of gypsy moth indoor and outdoor, but also can improve the gypsy moth death time.From home and abroad, analysis of LdNPV virulence differences found LdNPV seedlings from Inner Mongolia has high virulence. Pathogenicity of domestic two pathogenic strains of gypsy moth larvae from different regions are higher than the other three LdNPV strains from North America. Three disease genes of five LdNPV strains, compared to others, the gene E1and egt from Inner Mongolia appear larger difference.It is consistent with high virulence of the Inner Mongolia strains. |
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