Role of Other Non-Bt Genes In Managing Resistance to Bt Crops |
Using the diamondback moth/Bt broccoli system as a model, we haveinvestigated aspects important to the long-term deployment of this noveltechnology. Although the diamondback moth/Bt broccoli system may not exactlyduplicate the currently available insect/Bt crop systems such as crops likecorn, and potatoes, it can help identify areas for further work. Concurrentlywith more field studies conducted to refine the presently utilizedrecommendations, industry, public sector scientists, and farmers must worktogether to develop a second generation of technology and implementationstrategies to ensure the even longer term durability of Bt-transgenic plants.Within the plant showed that toxin expression is fairly uniform throughout theplant when the plant is in its vegetative stage17. We used cytoplasmic malesterile transgenic plants hemizygous for the cry1A(c) gene for field tests.Additional treatments were included for reference to reflect native diamondbackmoth populations and were 0% refuge and 100% refuge with no insect release in either(one replicate each). Counts of larvae (all stages)were taken at five periodsover the season beginning on 1 July and ending on 12 September. Leaf-dipbioassays with Javelin WG (Bt var. kurstaki; Novartis) to evaluate resistancewere done with progeny of the released larvae (time zero) and with progeny oflarvae counted in the final collection.