Evaluation of Resistance, Enzymatic Response, and Phenolic Compounds in Roots of F₁ Cucumber Hybrids to Fusarium Oxysporum F. Sp. Radicis-Cucumerinum

Cucumber (Cucumis sativus L.) is widely cultivated in many parts of the world. Its production is significantly affected by Fusarium root and stem rot, which is caused by the fungus Fusarium oxysporum f. sp. radicis-cucumerinum, a major disease of cucumber in some regions. Most of the management programs for the control of Fusarium root and stem rot are not successful; therefore, growing resistant cultivars may be the best solution. Use of disease-resistant cultivars is a key to environmentally friendly and economically sustainable disease control in modern crop production. To find resistance sources, 10 F₁ cucumber hybrids were screened against F. oxysporum f. sp. radicis-cucumerinum. Total phenolic content (PC), soluble peroxidase (POX), and polyphenol oxidase (PPO) activities were evaluated at 0, 4, and 8 days after inoculation. Significant differences were observed between resistant and susceptible genotypes in increase of total PCs and enzymatic activities at fourth day after inoculation. These findings can be used in breeding programs of cucumber aiming at creating F₁ cultivars resistant to Fusarium root and stem rot.