1,8-萘二甲酸酐对高浓度单嘧磺隆协迫下玉米的解毒作用

为避免单嘧磺隆对后茬玉米的药害、评估单嘧磺隆原药中存在的主要杂质对玉米生长的影响,利用室内毒力测定、温室栽培试验和生理生化试验,对单嘧磺隆对玉米的毒力及其高浓度协迫下1,8-萘二甲酸酐(NA)对玉米的解毒作用进行了研究。试验结果表明,单嘧磺隆对玉米掖单13和农大 3138的IC50值分别为6.42和84.38 μg/kg,对玉米生长有抑制作用;而原药中的主要杂质对玉米生长的抑制作用很小,其IC50值均大于619 μg/kg。单嘧磺隆对玉米离体乙酰乳酸合成酶(ALS)的I50值在15.15~66.73 nmol/L之间,高浓度单嘧磺隆对玉米活体ALS的活性也有抑制作用。温室盆栽试验结果表明,1 000 μg/mL 的NA对171.44 μg/kg单嘧磺隆协迫下的玉米掖单13和农大3138有解毒作用;游离辅氨酸含量和叶绿素含量测定结果表明,NA对自身抗逆性较强的玉米品种农大3138的游离辅氨酸含量和叶绿素生物合成影响不显著,但能明显提高单嘧磺隆协迫下自身抗逆性较差的玉米品种掖单13的游离辅氨酸含量,并在一定程度上提高叶绿素的含量。因此,NA对单嘧磺隆协迫下玉米的解毒作用与NA提高了玉米的抗逆性有关。

HJ] Detoxification of Naphthalic Anhydride to Maize Treated with High Concentration of Monosulfuron

In order to search for the rational application of monosulfuron and avoid possible phytotoxicityto succeeding maize (Zea Mays L.), evaluate the effect of the main impurities in monosulfuron technical on the growth of maize, detoxification of naphthalic anhydride (NA) to maize treated with high concentration of monosulfuron were studied by laboratory pot bioassay, by determination of the activity of acetolactate synthase (ALS) and other physiological and biochemical indicators such as content of chlorophyll and proline. The results of bioassay indicated that maize CAU 3138 was tolerant to monosulfuron with IC50 84.38 μg/kg and Yedan 13 was sensitive to monosulfuron with IC50 6.42 μg/kg. Impurities in monosulfuron technical had little herbicidal activity on CAU 3138 and Yedan 13 with IC50 more than 619 μg/kg. ALS activity determination in vitro indicated that I50 of monosulfuron for inhibition of ALS activity in three maize cultivars was 15.15~66.73 nmol/L, while inhibition of monosulfuron to ALS in vivo was weak. Pot bioassay indicated that, 1 000 μg/mL of NA haddetoxification to maize cultivars Yedan 13 and CAU 3138 when treated with monosulfuron at high concentration of 171.44 μg/kg. Determination of free proline and chlorophyll indicated that NA did not affect the content of free proline and total chlorophyll of CAU 3138, a powerful resistant maize cultivar obviously. Under the stress of monosulfuron, NA obviously increased the free proline content of a less resistant maize cultivar Yedan 13, but the increase of total chlorophyll was moderate. This indicated that the detoxification of maize under the stress of monosulfuron has direct relation to the increasing of maize tolerance due to the application of NA.