在温室盆栽条件下研究了接种AM(arbuscular mycorrhiza)真菌对灭菌土壤中胡萝卜生长及其辛硫磷残留的影响.试验设置不施加、低(200 mg·L^-1)、中(400 mg·L^-1)、高(800 mg·L^-1)等4个辛硫磷施用量水平,以及Glomus intraradices BEG 141(141)和Glomus mosseae BEG 167(167)和不接AM真菌的对照(CK)等3个接种处理.播种5个月后收获植株.辛硫磷在收获前14 d以灌根的方式施加.结果表明,尽管菌根侵染率在高辛硫磷施用量时有所降低,但均超过70%.辛硫磷施用量高低对于胡萝卜产量和地上部鲜重没有显著影响;在所有辛硫磷水平下,接种AM真菌均显著增加了胡萝卜产量和地上部鲜重.胡萝卜中辛硫磷残留随农药施用量增加而升高,接种AM真菌显著降低了胡萝卜根和地上部辛硫磷残留.无论在促生效应还是在降低辛硫磷残留方面,141菌剂要优于167菌剂.研究结果显示了AM真菌用于胡萝卜生产和降低农药残留的潜力.
A pot culture experiment was carried out to study the influence of arbuscular mycorrhizal(AM) fungi on the growth and phoxim residue of carrot(Daucus carota L).Four levels of phoxim(0,200,400,800 mg·L^-1) and two AM fungal inocula,Glomus intraradices BEG 141(141),Glomus mosseae BEG 167(167),and one nonmycorrhizal inoculum(CK),were applied to the sterilized soil.The plants were harvested after 5 months of growth and phoxim was irrigated into the root zone 14 d before plant harvest.Although decreasing with the increase of phoxim dosage,root infection rates of all the mycorrhizal plants were higher than 70%.Phoxim showed no significant dose effect on shoot wet weights and root yields,which were all increased by AM inoculation at four phoxim dosages.Phoxim residues in shoots and roots increased with the increase of phoxim dosage,but decreased by AM inoculation.In general,Glomus intraradices BEG 141 showed more pronounced effects on the growth and phoxim residue of carrot than Glomus mosseae BEG 167 did.Our results show a promising potential of AM fungi in carrot production and controlling pesticide residues.