Insecticidal Activity Of Transgenic Hybrid Poplar Clone 741 Carrying BtCry3A Genes

The molecule detection and insecticidal activity of transgenic hybrid poplar lone 741 [P.alba × (P. davidiana+ P.simonii)]×P. tomentosa] carrying a Bacillus thuringensis gene (BtCry3A) were analyzed by PCR, Southern bolt,ELISA and bioassays on different coleopteran insects.Seven transgenic subclones had been proved By the PCR detection carrying the BtCry3A genes. By the Southern bolt analysis, the Bt gene has been successfully conformed to transgenic hybrid poplar lone 741.The result of ELISA detection showed that the Bt toxoprotein content in body of transgenic subclone seedlings was different between May and September. In May,the distributing of toxoprotein in different part leaves did not form rule;but in September the toxoprotein of upper leaves had the highest content, middle part and underpart content were relatively lower, moreover the content in May was more than in September .The toxoprotein content in xylem was higher than in phloem in both monthes , and the content in May was more than in September .By laboratory test of insect feeding at room temperature, 22°C, 28°C and 35°C, seven transgenic subclones had a high resistance against plagiodera versicolora (Laicharting). The larval mprtality was up to 100% promptly within 1-2 days and the bodies of larvae broke. The higher temperature of feeding was, the insecticidal effect was the more obvious. The transgenic subclones showed certain insect resistance to the larvae of Apriona germari(Hope). Using the branch and xylem chipping breeding separately the larva of Apriona germari, the result showed that the branch and xylem chipping of transgenic subclones had obvious inhibitory activity on the development of the larvae. Weight of larvae feeding with transgenic subclones was lower than that feeding with nontransgenic contrast. Field bioassay showed that the Apriona germari could not spawn on the branches of 3 transgenic subclones among them. By field inoculation experiment, the livability of the larvae in seven transgenic subclones was lower than that in contrast.The resistance of transgenic subclone to different species of insect had selectivity. The seven transgenic subclones had no negative influence to growth and development of the larvae of Gypsy moth Clostera anachoreta (Fabricius).