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Bt cotton

Bethany Zumwalde

What is Bt cotton? How is it produced?

Advantages & limitations

Bt cotton study Inheritance of an insecticidal

Gene (cry1Ab) in Genetically Modified Cotton

Bt controversy

Outline

Genetically modified to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis.

Toxins are crystalline proteins (Cry-proteins) that target specific pests.

What is Bt cotton?

How is it produced?

Advantages & Limitations

Advantages

High insect specificity Control crop damage

and disease vectors Nontoxic to non-target

species Biodegradable Reduction of other

insecticides 94.5 million kg

(19.4%) from 1996 to 2005 for cotton

Yield increases

Limitations

Susceptible to resistance

High seed cost

Case Study: Inheritance of an Insecticidal Gene (cry1Ab) in Genetically Modified Cotton1

(Ghazanfar et al. 2012)

Using the Cry1Ab gene to create 6 crosses (2 transgenic lines & 2 non-transgenic lines)

Methods

(Ghazanfar et al. 2012)

PCR Southern blot Western blot Lab biotoxicity assay

Results

(Ghazanfar et al. 2012)

Highest heritability between crosses of transgenic and non-transgenic plants

Resistance was also highest in these crosses

The creation of new transgenic lines of Bt cotton is necessary to combat insect resistance

Conclusions

http://www.pakissan.com/english/advisory/biotechnology/images/bt.cotton.asia01.jpg

To Bt or not to Bt?

Questions?