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Two Different Bacillus thuringiensis Toxin Genes Confer Resistance to Diamondback Moth and Cabbage Worm in Transgenic Broccoli |
1, 1, 1, 1, 1, 1,Zhibiao Ye |
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Abstract Bt gene either Cry1Ac or Cry1C was individually transferred into broccoli (Brassica oleracea L. ssp. italica) genome via Agrobacterium-mediated transformation method using Green Comet hypocotyls as explants. And thirty five kanamycin-resistant broccoli plants respectively harboring Cry1Ac or Cry1C were obtained. PCR analysis with primers specific to Cry1Ac or Cry1C identified 27 Cry1Ac positive plants and 13 Cry1C positive plants. Southern blotting analysis with Cry1Ac or Cry1C as probes indicated the Bt gene was intergrated into plant genome. Transgenic broccoli lines with single copy transgene were inbreeded to homozygote and crossed to each other to obtain transgenic lines with double Bt genes. RT-PCR analysis showed the various expression levels in different transgenic lines. The Bt endotoxin protein was about 0.12~0.82 μg /g FW by ELISA assays. Both in vivo bioassays in laboratory and field test supported the improved insect resistance and the resistance level correlated with Bt expression level. Homozygotic broccoli lines with resistance to diamondback moth (Plutella xylostella L.) and imported cabbageworm (Peris rapae L.) were obtained trough selection in successive generations. Double Bt genes improved insect resistance in transgenic broccoli in this study.
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Received: 24 April 2009
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Corresponding Authors:
Zhibiao Ye
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