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United States Department of Agriculture

Agricultural Research Service

Title: Pink Bollworm (Pbw) Mortality and Cry1ac Toxic Protein in Nucotn 33b (Bt) Cotton Bolls Compared with Dpl 5415 Cotton Bolls.

Authors
item Henneberry, Thomas
item Jech, Lynn
item De La Torre, Theresa
item Maurer, Jamie - WCRL TEMP EMPLOYEE

Submitted to: Arthropod Management Tests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2002
Publication Date: December 31, 2002
Citation: HENNEBERRY, T.J., JECH, L.J., DE LA TORRE, T.M., MAURER, J. PINK BOLLWORM (PBW) MORTALITY AND CRY1AC TOXIC PROTEIN IN NUCOTN 33B (BT) COTTON BOLLS COMPARED WITH DPL 5415 COTTON BOLLS.. ARTHROPOD MANAGEMENT TESTS. 2002. FIELD AND CEREAL CROPS, M6 ASP

Interpretive Summary: Significant reductions in Cry1Ac insect toxic protein levels in transgenic cottons have been reported with increasing plant age after planting. We investigated PBW larval mortality on cotton plants in early-, mid-, and late season in relation to Cry1Ac levels occurring in 21-day-old Bt and DPL 5415 cotton bolls. DPL 5415 and Bt cotton seeds were planted on 19 Apr 2001 in 7 rows wide by 60 ft long plots at the Western Cotton Research Laboratory, Phoenix, AZ. Plots were arranged in an RCB design with four replications. Plots were furrow irrigated every 14 days. Last irrigations occurred on 21 Sept and plots were defoliated on 1 Nov. The amounts of Cry1Ac protein in Bt cotton bolls were determined on days 83, 118, and 152 after planting to determine amounts of the material in aging cotton plants in relation to PBW larval mortalities feeding on the bolls. Materials, sample preparations, solutions, extractions, dilutions, and assays were exactly as described in the Envirologix, Inc., Cry1Ab/Cry1Ac plate kit (Envirologix, Portland, ME). Samples were 0.6-cm boll pieces that were weighed and placed in 1.5-cm microcentrifuge tubes. Boll pieces were homogenized in extraction buffer with a fitted pestle. ANOVAs were conducted for all data and contingent upon a significant F test; means were separated using LSD method (P 0.05).

Technical Abstract: Significant reductions in Cry1Ac insect toxic protein levels in transgenic cottons have been reported with increasing plant age after planting. We investigated PBW larval mortality on cotton plants in early-, mid-, and late season in relation to Cry1Ac levels occurring in 21-day-old Bt and DPL 5415 cotton bolls. DPL 5415 and Bt cotton seeds were planted on 19 Apr 2001 in 7 rows wide by 60 ft long plots at the Western Cotton Research Laboratory, Phoenix, AZ. Plots were arranged in an RCB design with four replications. Plots were furrow irrigated every 14 days. Last irrigations occurred on 21 Sept and plots were defoliated on 1 Nov. The amounts of Cry1Ac protein in Bt cotton bolls were determined on days 83, 118, and 152 after planting to determine amounts of the material in aging cotton plants in relation to PBW larval mortalities feeding on the bolls. Materials, sample preparations, solutions, extractions, dilutions, and assays were exactly as described in the Envirologix, Inc., Cry1Ab/Cry1Ac plate kit (Envirologix, Portland, ME). Samples were 0.6-cm boll pieces that were weighed and placed in 1.5-cm microcentrifuge tubes. Boll pieces were homogenized in extraction buffer with a fitted pestle. ANOVAs were conducted for all data and contingent upon a significant F test; means were separated using LSD method (P ? 0.05).

Last Modified: 12/21/2014
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