Acute toxicity evaluation of herbicide-resistant transgenic chrysanthemum (Chrysanthemum morifolium Ramat.): Effect on Daphnia magna fed with herbicide-resistant transgenic chrysanthemum

Herbicide resistant transgenic chrysanthemum was developed by inserting phosphinothricin acetyltransferase (PAT, bar), a modified gene from the soil bacterium Streptomyces hygroscopicus, into the genome of a conventional variety of chrysanthemum (Peace copper).Herbicide resistant transgenic chrysanthemum used for the test was confirmed to express the PAT gene by polymerase chain reaction (PCR) and immunostrip.The acute toxicity effect of herbicideresistant transgenic chrysanthemum and non-genetically modified (non-GM) counterpart chrysanthemum (Chrysanthemum morifolium Ramat.) on Daphnia magna was investigated at different concentrations (0, 50, 100, 200, 500, 1,000, and 2,000 mgL -1 ).Feeding tests were conducted with Daphnia magna to evaluate the environmental risk of transgenic chrysanthemum, including herbicide-resistant gene.Daphnia magna was fed 100% ground chrysanthemum suspension, herbicide-resistant chrysanthemum or non-GM chrysanthemum.As a result, the feeding test showed no significant differences in the cumulative immobility or abnormal response between Daphnia magna samples fed on herbicide-resistant chrysanthemum and non-GM chrysanthemum.The 48 h-EC 50 (effective concentration 50) values of the non-GM chrysanthemum and herbicide-resistant chrysanthemum were 333.6 mg L -1 (95% confidence limits: 211.4 -526.2 mgL -1 ) and 348.5 mgL -1 (95% confidence limits: 228.1 -532.5 mgL -1 ), respectively.The chrysanthemum NOEC (no observed effect concentration) value for Daphnia magna was suggested to be 100 mgL -1 .Based on these results, there was no significant difference in toxicity for non-target organisms (Daphnia magna) between the herbicideresistant chrysanthemum and non-GM counterparts.