Thirteen commercial varieties of transgenic Cry1Ac Bacillus thuringiensis Berliner (Bt) cotton were examined across two sites in 2000 for potential factors that impact endotoxin expression. In all cases, two varieties (NuCOTN 33B and DP 458B/RR, Delta & Pineland Co., Scott, MS) expressed more Cry1Ac than the other 11 varieties in various plant structures. These two varieties share the same pare...
