About
  PDF
Full Text
(154 K)

Bollgard II®: A Step Change for Insect Control in Cotton

Daniel L. Pitts, Walt Mullins, Graham P. Head, and H. Keith Reding

ABSTRACT

Bollgard™ cotton, which contains the Cry1Ac gene for in plant production of the Bacillus thuringiensis endotoxin, was introduced to the cotton market in 1996. This transformation resulted in very high insecticidal expression to the tobacco budworm (Heliothis virescens), pink bollworm (Pectinophora gossypiella) and European corn borer (Ostrinia nubilalis Hubner) and also provided good activity to cotton bollworm (Helicoverpa zea) in cotton. To augment the performance of Bollgard, a second gene Cry2Ab, was ballistically inserted into plant material containing the Cry1Ac gene. Prodigy from this insertion event was designated MON 15985 and contained the D&PL 50 Bollgard™ background. Trade named Bollgard II™, it contains genes for production of both the Cry1Ac and Cry 2Ab insecticidal active proteins. This two-gene product, which received EPA approval December 23, 2002, provides substantially improved activity against cotton bollworm, beet armyworm (Spodoptera exigua), soybean looper (Pseudoplusia includens), fall armyworm (Spodoptera frugiperda) and several other lepidopteran species in cotton. Along with greater spectrum of activity, the two proteins expressed in Bollgard II are sufficiently dissimilar to greatly deter resistance development in field populations. Laboratory data also demonstrate the propensity of cross-resistance of Cry1Ac and 2Ab to be minimal based on studies using Helicoverpa zea (Jackson, 2002), Heliothis virescens (Gould, 1995) and pink bollworm (Pectinophora gossypiella) (Head, 2001). By comparison, the Cry2Ab protein present in Bollgard II cotton is expressed at a high dose for tobacco budworm and, in combination with Cry1Ac, presents two "high dose" proteins for control of the tobacco budworm in Bollgard II cotton. Overall, Bollgard™ II provides increased efficacy to (Helicoverpa zea), has an expanded spectrum of activity including armyworm and soybean loopers (Pseudoplusia includens), is a better resistance management tool, offers better yield potential and can ease and simplify insect control for growers.





[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page

Document last modified April 16, 2003