Enantioselective Phytotoxicity of Imazamox Against Maize Seedlings.
There is increasing concern about the enantioselective effects of chiral herbicides. To study the enantioselective toxicity of the chiral herbicide imazamox on maize, maize seedlings (Zhengda 619, Zea mays L.) were exposed to imazamox racemate and enantiomers in hydroponic experiments. The results showed that imazamox enantiomers selectively affected maize. The effective concentration of Rac-, S- and R-imazamox that caused 50 % inhibition after 5 days treatments (EC50,5d) were 0.4212, 1.2142 and 0.2460 mg L(-1), respectively, for maize root length; 0.0002, 0.1005, 0.0032 mg L(-1), respectively, for maize root fresh weight; 0.7114, 1.4056 and 0.4530 mg L(-1), respectively, for maize shoot height; 0.6220, 1.5418, 0.2286 mg L(-1), respectively, for maize shoot fresh weight; and 0.1100, 0.3306, 0.0307 mg L(-1), respectively, for the total chlorophyll content of leaves. The root morphological parameters and root activity reflected the toxicity effects in the order R-imazamox > Rac-imazamox > S-imazamox. Maize roots were more sensitive to imazamox than maize shoots. The chiral herbicide imazamox poses enantioselective phytotoxicity on maize seedlings: the order of toxicity is R-imazamox > Rac-imazamox > S-imazamox.
Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning, Guangxi, 530005, People's Republic of China.
Jing
J
Wei
Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning, Guangxi, 530005, People's Republic of China.|Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Xishuangbanna, Yunnan, 666303, People's Republic of China.
Xiaoxiao
X
Zhang
Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning, Guangxi, 530005, People's Republic of China.
Xuesheng
X
Li
Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning, Guangxi, 530005, People's Republic of China.
Dongqiang
D
Zeng
Institute of Pesticide and Environmental Toxicology, Guangxi University, Nanning, Guangxi, 530005, People's Republic of China. jeffthh@163.com.
Huihua
H
Tan
D006540:Herbicides / Q000737:chemistry / Q000633:toxicity*; D007093:Imidazoles / Q000737:chemistry / Q000633:toxicity*; D018515:Plant Leaves / Q000187:drug effects; D018517:Plant Roots / Q000187:drug effects; D036226:Seedlings / Q000187:drug effects; D013237:Stereoisomerism; D003313:Zea mays / Q000187:drug effects*
D006540:Herbicides; D007093:Imidazoles; C494197:imazamox
Enantioselective effect; Imazamox; Maize; Phytotoxicity