Molecular biology and physiology: Agronomic performance and crop composition of genetically engineered cotton tolerant to hppd inhibiting herbicides

Abstract

Genetically engineered cotton tolerant to twoherbicides with unique modes of action has beendeveloped by Bayer CropScience. This cottonevent, referred to as HPPDi cotton, was developedthrough Agrobacterium-mediated transformationto express the modified 5-enolpyruvylshikimate3-phosphate synthase protein (2mEPSPS) andmodified 4-hydroxyphenylpyruvate dioxygenase(HPPD W336) proteins, which respectively confertolerance to glyphosate and HPPD inhibitor herbicidessuch as isoxaflutole. The objective of the studywas to compare HPPDi cotton (genetic backgroundCoker 312) with non-genetically engineered Coker312 and commercial reference varieties. Agronomicparameters were collected at 15 field sites includingplant population (i.e., stand counts), morphology (i.e.,plant mapping) and yield. Lint was analyzed for lintquality via high volume instrument (HVI). Compositionalparameters (proximates, anti-nutrientsand other components) were analyzed in fuzzy seedproduced from eight sites. Statistical analysis wasperformed to compare HPPDi cotton treated or nottreated with isoxaflutole and glyphosate to Coker 312(the non-genetically engineered conventional counterpart).The results of this comparative assessmentindicate that HPPDi cotton is substantially equivalentto its non-genetically engineered conventionalcounterpart for agronomic parameters, lint quality,and composition as it does not exhibit unexpectedagronomic, lint or compositional characteristics.