Three Kinds Of Resistance Near-isogenic Lines Of Diamondback Moth Biochemical Genetic Basis Of Research

Plutella xylostella (L.) is a pest of cruciferae vegetable in all of the world. Since 1960s last century, because of the extensive usage of chemistry insecticide, adding the special life history of this kind of pest, a lot of valid insecticide originally lost the prevention and cure result one after another. So people all of the world began to concern about this problem.There have already lots of domestic and international reports about the insect resistance. But lacking of the insect inherit background knowledge made the resistant reserch still be placed in physiologic and biochemistric level. Only in recent years can the moleacular biology methords be introduced into this reigon. Similar situation also exists in the resistant research in dimondback moth. The current study shows that Physiologic and biochemistric mechanism of resistance contributed to three factors: decling of epidermic penetrability, changing of detoxifa- cation ability and drone enzymes. Most research result shows mechanisms of resistance are different because of the diffrence of reigon,strain and culture methods.In this study,we used dimondback moth(NILs of dimehypo-resistance,deltamethrin- resistance,cartap-resistance) cultured in isolated and synchronous way as object and suspectible strain as comparision,and did biochemistric and inherited research.We drown our conclusion as followed:(1) We analysis three kinds of detoxifacate enzymes of moth and pupa in resistant dimoncback moth and their NILs.Data shows the activities of CarE and GSTs are higher than that of suspectible strains. The activities of AchE is lower than that of suspectible strains.There were no significant diffrence in the activities of AchE and CarE beteween resistant and susceptible strains. And there was significant diffrence in the activities of GSTs beteween resistant and susceptible strains . So GSTs is related to resistance .CarE and AchE are not related to resistance.(2) PAGE of esterase isozymes in NILs of four kinds of dimondback moth pupa shows the number of special esterase isozymes in NILs of dimehypo and cartap-resistance are equal.But the composing is different .This result is differ from theformer reports .The number of esterase isozymes in NILs of deltamethrin- resistance is six less than that of the other two NILs. The other esterase isozymes are uniform, and the activities of them are lower than that of the other two NILs. (3) DNA from susceptible and three kinds of NILs was compared by using optimized randomly amplified polymophic DNA methods with 40 primers from Shanghai Shenggong.There are 6 primers which can produce special DNA bands which are very stable .We got 2 special DNA bands in susceptibale strain and 8 special DNA bands which were related to resistance. The result suggests three resistance strains have obvious changes in DNA level. The result suggests that insectcide resistance is ralated to the changes in genomic DNA in dimondback moth.(4) We cloned and sequenced 3 from all of the special DNA bands:A1,A2 and A3. A1 and A2 can exsist in suscepitable strain and NILs of dimehypo-resistance and cartap-resistance other than NILs of deltamethrin-resistance. A3 only exists in deltamethrin- resistance .What we have done will help to transfom these spesial DNA bands to SCAR marker.