Influence of Triflumurón on arbuscular mycorrhizal fungi and root colonization of soybean (Glycine max var. sojae)

Three different concentrations (0,02; 0,2 and 2 ppm) of the insecticide Triflumurón were assessed for their effect on mycorrhizal root colonization by Glomus mosseae and indigenous arbuscular fungi soybean (Glycine max var. sojae Nidera cv 4656 ). A greenhouse experiment was carried out in pots containing a mixture of sieved soil (Argiudol) and quartz 2:3 (V/V), additioned with water solutions of Triflumurón 2, 0,2 and 0,02 ppm. Controls were made without the addition of insecticide. G. mosseae inoculum consisted of 5 g of rhizospheric soil containing 41 spores or sporocarps (mostly one spored) per gram of soil, which was added during seeding. Plants were cultivated for 8 weeks in the greenhouse at 20-25 C° and mycorrization percentage and dry weight of shoot and root registered. On other hand, the effect of Triflumurón on spore germination of Glomus mosseae, Gigaspora rosea and Scutellospora castanea was evaluated in vitro on Petri dishes experiment. The insecticide did not affect total plant growth and root colonisation by Glomus mosseae, but decreased root infection by indigenous arbuscular mycorrhizal population. Spore germination rates of Glomus mosseae, Gigaspora rosea and Scutellospora castanea were not affected by the addition of Triflumurón to the Petri dishes.

Key words: Triflumurón, Glomus mosseae, Scutellospora castanea, Gigaspora rosea, Glycine max var. sojae.