The effect of arbuscular mycorrhizal fungus Glomus intraradiceson some growth and physiological parameters in Plantago lanceolata plants under lead toxicity

High concentrations of heavy metals have been shown to adversely affect the size,diversity and activity of plant populations in soil.Lead is a non-essential element that negatively affects plant growth and its development.The aim of this work was to determine how the diversity of arbuscular mycorrhizal (AM) fungi is affected by the addition of sewage-amended sludge containing heavy metals in a long term. In this study, the effect of an arbuscular mycorrhizal (AM) fungus Glomus intraradices on some growth and physiological traits such as fresh and dry weight of root and shoot, photosynthetic pigments content,in Plantago lanceolata plants under the toxic levels of lead was investigated. The experiment was performed by using two treatments (mycorrhizal and non-mycorrhizal) and two lead concentrations (0, 2.8mg/kg of soil).Arbuscular mycorrhizal fungi had a significant influence on root and shoot fresh and dry weights, where the presence of AM fungus caused a decrease in the negative effect of Pb toxicity. Root length decreased due to an increase in Pb concentration, but there was no corresponding effect on the shoot length. Colonized plants showed less negative effect of Pb on their root length than non-AM plants. Determination of chlorophyll a and b content showed decreased chlorophyll content in both AM and non-AM plants by increasing Pb concentration, but this decrease in the mycorrhizal plants was lower than in non-mycorrhizal plants. Root length colonization was measured by gridline intersect method. Mycorrhizal colonization decreased due to the Pb exposure significantly.

کلیدواژه ها:

Mycorrhiza ، Chlorophyll ، Lead ، Plantago lanceolata