Agronomic Performance and Crop Composition of Genetically Engineered Cotton Tolerant to HPPD Inhibiting Herbicides

Abstract

Genetically engineered cotton tolerant to two herbicides with unique modes of action has been developed by Bayer CropScience. This cotton event, referred to as HPPDi cotton, was developed through Agrobacterium-mediated transformation to express the modified 5-enolpyruvylshikimate 3-phosphate synthase protein (2mEPSPS) and modified 4-hydroxyphenylpyruvate dioxygenase (HPPD W336) proteins, which respectively confer tolerance to glyphosate and HPPD inhibitor herbicides such as isoxaflutole. The objective of the study was to compare HPPDi cotton (genetic background Coker 312) with non-genetically engineered Coker 312 and commercial reference varieties. Agronomic parameters were collected at 15 field sites including plant population (i.e., stand counts), morphology (i.e., plant mapping) and yield. Lint was analyzed for lint quality via high volume instrument (HVI). Compositional parameters (proximates, anti-nutrients and other components) were analyzed in fuzzy seed produced from eight sites. Statistical analysis was performed to compare HPPDi cotton treated or not treated with isoxaflutole and glyphosate to Coker 312 (the non-genetically engineered conventional counterpart). The results of this comparative assessment indicate that HPPDi cotton is substantially equivalent to its non-genetically engineered conventional counterpart for agronomic parameters, lint quality, and composition as it does not exhibit unexpected agronomic, lint or compositional characteristics.