摘 要 ：室内用砂培法测定11种小麦品种对苯磺隆的相对敏感性,其敏感性有较大差异。碧玛4号、维麦8号对苯磺隆有很强的耐药性,IC50可分别达到502.6和409.3 ai μg/kg,济13号为156.9 ai μg/kg,鲁麦22号、黄县大粒对苯磺隆较为敏感,IC50低于45.0 ai μg/kg。以上5种小麦离体ALS对苯磺隆的敏感性没有明显差异,敏感品种黄县大粒IC50为154.2nmol/L,甚至较维麦8号149.3nmol/L略高。ALS活体试验表明,小麦可以很快恢复苯磺隆对ALS活性的抑制,且耐药型品种恢复能力较强,碧玛4号、维麦8号ALS恢复活性只需1.5天,敏感品种需3天。碧玛4号、维麦8号除草剂解毒酶系GSTs相对于敏感品种对苯磺隆有较大的反应幅度和较短的反应时间,第2天就分别达到1.46、1.42的峰值,而济13号、鲁麦22号、黄县大粒变化幅度较小,第3天才达到峰值,活性分别为1.39、1.33和1.32。研究表明,小麦各品种对苯磺隆的耐药能力产生差异的主要原因之一是小麦GSTs对苯磺隆的代谢所致,而与小麦ALS对苯磺隆的敏感程度无关。
Abstract:We measured the tolerance of various wheat varieties to tribenuron-methyl. Bima 4 and Weimai 8 had the higher resistance and the IC50 was 502.6 ai μg/kg and 409.3 ai μg/kg, Ji13’ s IC50 was 156.9 ai μg/kg, and Lumai 22 and Huangxiandali were sensitive and the IC50 were under 45.0ai μg/kg. But these 5 varieties’ target enzyme of tribenuron-methyl acetolactate synthase had no obvious difference on sensitivity to tribenuron-methyl, and indeed Huangxiandali IC50 (154.2nmol/L) was higher than Weimai 8 (149.3nmol/L). Wheat ALS activity could renew the inhibition of tribenuon-methyl rapidly, Bima 4 and Weimai 8 only needed 1.5 day, but the sensitive varieties needed 3 days. Bima 4 and Weimai 8’ s GSTs had a rapidly and stronger response to tribenuron-methyl than the susceptive varieties, they reached the peak value 1.46 and 1.42 in two days. Ji13, Lumai 22 and Huangxiandali reached the peak value 1.39, 1.33, 1.32 in 3 days. The result of the study showed that the reason of various wheat varieties have different tolerance to tribenuron-methyl was not the difference of sensitivity of ALS, but the enhancement of wheat’ s GSTs activity.