Studies On The Insect-resistance And Investigation Of Arthropod Community With The Transgenic Plants

On the base of the plant with two Bt genes (Bt Cry3A and Bt Cry1A) poplars,Bt Cry3A(CC lines ) genes and Bt Cry1A (pB lines )genes poplars fed to Fall webworm [Hyphantria.cunea] on the filed, Laicharting [Plagiodera versicolora]in the lab, CK is non transgenic 741 popolar. Study to the resist insects spectrum with two Bt genes poplars.To investigated the arthropod communities of the eight years triploid Chinese white poplar transformed with Bt Cry1A genes lines.To explore the insect gene in the adult tree was expressed stability, we studied the expression of the Bt genes and its stability in the triploid of Chinese white poplar was studied.Chlorophll content,Fv/Fm,PI value and photosynthesize character of function leaves were measured.Results were showed as follow:(1)The leaves with two Bt genes (Bt Cry3A and Bt Cry1A)) poplars,Bt Cry3A(CC lines ) genes and Bt Cry1A (pB lines )genes transgenic isogenic poplars lines fed to Laicharting [Plagiodera versicolora] in the lab. The results showed that seven pC lines :pC1,pC2,pC3,pC4,pC5,pC6,pC9 and CC five lines:CC84,CC71,CC11,CC22,CC53 were high insect resistance.the mortality was 100%,but the CK and pB lines was only 8% and 25% mortality.The leaves with two Bt genes (Bt Cry3A and Bt Cry1A)) poplars,Bt Cry3A(CC lines ) genes and Bt Cry1A (pB lines )genes transgenic isogenic poplars lines fed to Fall webworm [H.cunea] on the filed, after 21d, take the insects in the lab. The results showed that pC lines :the mortality of pC1,pC2,pC4,pC6,pC9 and Bt Cry1A gene lines pB17,pB29 were above the 95%. The lines were high insect resistance.CC and CK's mortality were under 20% and 8%.Fed on Laicharting [Plagiodera versicolora] in the lab showed that pC and CC lines were died in the one or two instar, the test was studies on the instar age of Laicharting body length and the head wide.The results of fed on the Fall webworm [H.cunea] after 21d on the filed,the leaves with CK fed to Fall webworm insects were almost 16.82% in the six instar, the inscts with pB lines were in the two instar. The weight of the alive insects about pC and pB lines were 30-75mg, far below the weight of CK and CC (90.0-160.0mg).the body length of the pC and pB lines were below the CK and CC's lines. It could extend the larval developmental period of Fall webworm[H.cunea] lower rates of larval body length, reduced pupa weight of the older ones, and even express certain resistance to insects.It was founded that the two Bt genes 741 popolar have effective with the Iepidopteran pests and pest resistance Coleoptera , it's an important role to produce or delay the insects talerace .It could widen the insects resistance spectrum and defer the pest's durability to the insecticidal agents.it's significant for the resist insects breeding new varieties plants.(2) After eight years'filed planting, some transgenic isogenic lines were detected by PCR and proved that the exogenous genes were stable in the poplar genome.(3) The physiological indicators of transgenic plants shoued that: Compared with popolar 741, the chlorophll a and a/b content have no difference ,but the chlorophll b,a+b content were below popolar 741;The Fv/Fm value have no differnce with the 741 popolar. The net photosynthesize rate of most transgenic subsclones were higher than the 741 popolar. 20 subsclones with the PI value of transgenic poplar were higher than the 741.(4) The results of arthropod community were 11 order,26 species of arthropod 28 families. The pests were 11 species . 39.2% of all community, The natural ememies had 10 species, 35.7% of all the community,and the natural insects had 7 species, 25% of all community,the main insect was Hyphantria cunea. The rate between natural enemy and pest is 1:1.1.These results shows that the number of pest decrasing have no influence with the arthropod communities of the eight years triploid Chinese white poplar.Survey of the leaf area in the fall shows that insect-resistance ranges substantially in different transgenic subclones: 4 subclones have not been grazed by Hyphantria cunea; leaf area eaten rate of 10 subclones are less than 10%, while that of other 6 subclones are 10%-15% . It proved that the exogenous genes were stable in the eight years triploid Chinese white poplar.(5) The larval death index with 1a triploid Chinese white poplar of Lymantria dispar(Linnacus) and leaf area eaten rate in eight years triploid Chinese white poplar is 0.411, The larval death index with 1a triploid Chinese white poplar of Clostera anachoreta (Fabricus) and the weight and body length with Hyphantria cunea were signifecantly correlated.There was an obvious correlation between toxin protein content with the leaf area eaten rate,the insects weight and body length , It proved that the exogenous genes were stable in the eight years triploid Chinese white poplar.