Synergistic effect between Pseudomonas putida and arbuscular mycorrhizal fungi on Vicia faba L. growing in heavy metals polluted soil

摘要

Field experiment was carried out to examine the interactions between Ps. putida and arbuscular mycorrhizal (AM) fungi and their effects on nodulation and some elements distribution in faba bean plants (Vicia faba L.) and soil in the presence of 25 or 50% mineral fertilizers (NPK). The soil before cultivation has noticeable amounts of copper and zinc in total form also Cu and Zn in available form. During the plant growth, the soil pollution rate increased with the investigated elements except Cu which decreased. The best treatment led to decrease the soil pollution of lead is to inoculation plants with AM fungi plus Ps. putida and in combination with 50% NPK. Stimulation of AM fungi colonization by a Ps. putida was noted. AM fungi alone significantly enhanced nodulation. Significantly more nodules had developed on the root systems of faba bean plants inoculation with Ps. putida + AM fungi compared to AM alone or uninoculated control. Plant inoculation with both organisms increased the population of Pseudomonas spp. The best treatments to decrease Cu pollution are those inoculated with AM fungi plus 25% NPK followed by AM fungi + Ps. +50%NPK in mature stage. All plant organs contained Pb in mature stage; the beast treatment to decrease Pb pollution is to use 25% NPK plus AM fungi. The concentration of zinc in all young plant parts is higher than 400 mg/kg then decreased when the plant growth reached mature stage. The use of 50% NPK plus AM fungi is the best treatment to decrease Zn content in the tested plant.