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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?