不同类型杀线剂对甘薯茎线虫趋化性的影响

Effects of different types of nematicides on the chemotaxis of Ditylenchus destructor

实验室条件下研究了涕灭威、甲氨基阿维菌素苯甲酸盐和丙溴磷在低剂量胁迫下对甘薯茎线虫趋化性的影响。结果表明:在无药剂胁迫情况下甘薯茎线虫对灰霉菌、半裸镰刀菌的趋化性最强,其次为马铃薯,对甘薯无趋性。在含有5～5×10-2μg/mL涕灭威、甲氨基阿维菌素苯甲酸盐和丙溴磷的水琼脂平板,线虫的趋化性均受到抑制,且甲氨基阿维菌素苯甲酸盐的抑制活性高于其他2种药剂;线虫经10-1～10-3μg/mL的涕灭威、甲氨基阿维菌素苯甲酸盐和丙溴磷浸渍24h后采用灭菌去离子水清洗3次并恢复24h后,线虫的趋性仍受到抑制。值得注意的是,在含5×10-3μg/mL丙溴磷水琼脂或经丙溴磷10-3～10-4μg/mL处理后,线虫的趋性发生了改变,表现出对甘薯块具有一定的趋性。

The effects of different type of nematicides on the chemoreceptive activity of Ditylenchus destructor were tested by using a chemoreception bioassay in vitro. Nematodes were placed in the centre of a petri dish containing 1% agar base. The attractants, including Botrytis cinerea, Fusarium semitectum, potato cutting and sweet potato cutting, were placed at equal distance from the centre. The 1% water agar discs were used as blank. The results showed that B. cinerea and F. semitectum were significantly much more attractive than potato cutting, and the nematode had no tendency toward sweet potato cutting. The chemoreception response of D. destructor was inhibited when bioassay was performed in 1% agar plate containing 5--5 ×10^-2μg/mL aldicarb, emamectin benzoate and profenofos, respectively. In the other experiment, the nematodes were incubated in nematicide solution or control solution for 36 h, subsequently washed three times and then kept in distilled water for 24 h. Nematode chemoreceptive response was inhibited at very low concentration （10^-1-10^-3μg/mL） of aldicarb, emamectin benzoate and profenofos by using the same bioassay methods. The tendency toward sweet potato cutting by the nematodes tested in agar plate containing 5 ×10^-3μg/mL profenofos or treated with 10-3-10^-4 μg/mL profeno- fos was enhanced.