The morphological and physiological traits of Cucumis sativus- Phelipanche aegyptiaca association affected by arbuscular mycorrhizal fungi symbiosis

The plant symbiotic fungi, Arbuscular mycorrhizae (AM), increases host competency and causes partial control of Egyptian broomrape Phelipanche aegyptiaca (Orobanchaceae). In this study, a greenhouse experiment was designed to investigate the AM efficacy on the morphological and physiological traits in the association of cucumber and P. aegyptiaca. Findings showed that the broomrape contamination increased the activity of ascorbate, peroxidase, and catalase in cucumber. In contrast, AM decreased ascorbate, peroxidase activity and increased total phenolic compounds. However, AM in P. aegyptiaca-infected genotypes had no significant effect on malondialdehyde and hydrogen peroxide content. In AM inoculated treatments, the height and number of cucumber leaves were unaffected by P. aegyptiaca infestation. Also, AM decreased the harmful effects of the P. aegyptiaca by reducing the total dry weight and number of attachments, increasing the leaf area, the shoot, and the dry root weight of cucumber genotypes. Despite the positive effect of AM, about 35 and 50% reduction in shoot and dry root weight of cucumber indicated high susceptibility of the host. Overall, It seems that the AM cannot be effective as a primary broomrape control strategy in cucumber.