Detection of unintended effects in genetically modified herbicide-tolerant (GMHT) rice in comparison with non- target phenotypic characteristics

Abstract

In the process of safety assessments of genetically modified (GM) crops, particular attention should be paid to their unintended effects. This study was focused on detection of unintended effects in genetically modified herbicide-tolerant (GMHT) rice (Oryza sativa L. ssp. indica) Bar68 -1 in comparison with non-target phenotypic characteristics between Bar68 -1 and its unmodified counterpart, D68. The results showed that there were no significant differences between Bar68 -1 and D68 in most of the morphological or agronomic traits, including main culm length, main culm thickness, flag leaf length, tillering dynamics, seed setting, 1000-grain weight, grain length, grain width, length-width ratio of grain, brown rice length, brown rice width, length-width ratio of brown rice, grain yield, biomass of aerial part, yield, rate of seed germination and ratooning. There were statically significant differences between Bar68-1 and D68 in the parameters such as flag leaf width, spikelets per panicle, panicle length and harvest index, but the values of the changed traits are within rice normal ranges and in the same scales according to GB/T 19557.7 - 2004 from Chinese standard and SES from IRRI. Therefore, these differences were not considered biologically relevant. Results indicated that the unintended effects were not detected in Bar68-1 in this study. Key words: Unintended effects, safety assessment, biosafety, GM crops, herbicide tolerance, transgenic plant, rice (Oryza sativa L.), bar gene.