Investigation of peroxidase and polyphenol oxidase enzymes quantitative changes in sensitive and tolerant cucumber to root knot nematode, due to mycorrhizal fungus

The aim of this study was to compare the effect of Funneliformis mosseae</em> mycorrhizal fungus on the activity of defense enzymes produced by Meloidogyne incognita</em> attack on roots of tolerant and sensitive cucumber cultivars. For this purpose, an experiment was conducted in a greenhouse with four treatments and four replications in a completely randomized design (split design in time). Cucumber seedlings were planted in sterile soil. Mycorrhizal treatments were added to 75 grams inoculum per kilogram soil. 45 days after F. mosseae</em> inoculation, 1500 J2 were added per each kilogram soil. The quantitative activity of peroxidase and polyphenol oxidase enzymes was measured after six and eigh days after inoculation. The results showed that the activity of the enzymes in inoculated with nematode increased in comparison with the control plants. In the inoculated with AMF alone, the average activity of enzymes in different days of measurement was higher than control and nematode treatment. In both cultivars, the activity of these enzymes increased significantly in nematode with mycorrhizal fungus. Totally, the activity of peroxidase and polyphenol oxidase enzymes in tolerant cultivar was significantly higher than sensitive in the same treatments and days of measurement which can be related to these enzymes roll in increasing tolerance to the nematode. Effect of mycorrhizal fungus on increasing the amount of defense enzymes in the treatments are considered as other results of this research.