Arbuscular mycorrhizal fungi improve uptake and control efficacy of carbosulfan on Spodoptera frugiperda in maize plants

BACKGROUND Inoculation of arbuscular mycorrhizal (AM) fungi in soil can promote the uptake of nutrients and xenobiotics by plants. In this study, the effects of arbuscular mycorrhizal fungi (including Glomus intraradices and Glomus mossea) on the growth of maize, the uptake of carbosulfan and the control efficacy on Spodoptera frugiperda were investigated through maize seed coating. RESULTS Results from the pot experiment showed that carbofuran reduced the mycorrhizal colonization of AM fungi in the early stage of the experiment. The inhibiting effect disappeared in 21-49 DAP, whereas the mycorrhizal colonization rate under the G. intraradices treatment was maintained at approximate to 90%. Compared with noninoculated treatment, the fresh weights of roots in G. intraradices and G. mosseae treatments increased by 20-41% and 10-23%, respectively. Mycorrhizal treatment could significantly increase the transmission rates (root/soil and leaf/stem) and the carbosulfan accumulation in maize. During the harvest period, the control efficacy against S. frugiperda in mycorrhizal treatment was significantly higher than that in noninoculated treatments (P < 0.05) in both Guangzhou and Nanning. CONCLUSIONS Inoculation with AM could accelerate the degradation process of carbofuran in soil and the propagation of carbofuran from soil to plants. Glomus intraradices showed more pronounced effects than G. mosseae on both plant growth and carbosulfan content in plants and soil. The experimental results showed that inoculation of AM fungi increased the accumulation of carbofuran in plants, improved the effective utilization rate and enhanced the control efficacy against S. frugiperda.