Status of PBW resistance to Bollgard cotton in India

In monitoring field performance of the 2009 cotton crop in the state of Gujarat in western India, Monsanto and Mahyco scientists detected unusual survival of pink bollworm to first-generation, single-protein Bollgard I (event MON531) cotton. Testing was immediately conducted for resistance to Cry1Ac, the Bt protein in Bollgard I cotton. Pink bollworm resistance to Cry1Ac was confirmed in four districts in the State of Gujarat. Gujarat is one of nine states in India where cotton is grown. In this presentation we will summarize the field and laboratory evidence demonstrating resistance of pink bollworm to Cry1Ac, and the lack of cross resistance to Cry2Ab, the additional Cry toxin in second-generation, Bollgard II cotton, introduced in India in 2006. We will discuss factors that have contributed to resistance in Gujarat and the striking contrast with 14 years of resistance-free use of Bollgard in the southwestern US. Lastly, we will overview the diversity of efforts underway in India to thwart future resistance development in pink bollworm.