Open Access

ARTICLE

Uniting the Role of Entomopathogenic Fungi against Rhizoctonia solani JG Kühn, the Causal Agent of Cucumber Damping-Off and Root Rot Diseases

Abdelhak Rhouma¹, Lobna Hajji-Hedfi^1,*, Nahla Alsayd Bouqellah^2,*, Pravin Babasaheb Khaire³, Samar Dali¹, Omaima Bargougui¹, Amira Khlif¹, Laith Khalil Tawfeeq Al-Ani⁴

1 Research Laboratory of Agricultural Production Systems and Sustainable Development (LR03AGR02), Carthage University, Regional Centre of Agricultural Research of Sidi Bouzid, CRRA, Sidi Bouzid, 9100, Tunisia
2 Science College, Biology Department, Taibah University, Almadina, 42317, Saudi Arabia
3 Department of Plant Pathology and Microbiology, Mahatma Phule Krishi Vidyapeeth, Rahuri, 413722, Maharashtra, India
4 School of Biology Science, Universiti Sains Malaysia, Minden, 11800, Malaysia

* Corresponding Authors: Lobna Hajji-Hedfi. Email: ,; Nahla Alsayd Bouqellah. Email:

Phyton-International Journal of Experimental Botany 2024, 93(11), 2857-2881. https://doi.org/10.32604/phyton.2024.057591

Received 21 August 2024; Accepted 16 October 2024; Issue published 30 November 2024

Abstract

Beauveria bassiana and Metarhizium spp. are entomopathogenic fungi with potential applications beyond insect pest control, including plant disease suppression, plant growth promotion, and rhizosphere colonization. This study investigated the plant growth-promoting characteristics and extracellular enzyme activities of Metarhizium spp. and B. bassiana in relation to phytopathogen interactions and plant growth. Additionally, the efficacy of these fungi in mitigating damping-off and root rot caused by Rhizoctonia solani on cucumber plants was evaluated in vitro and in vivo. Results indicate that B. bassiana and M. anisopliae produce indole-3-acetic acid, hydrocyanic acid, and hydrolytic enzymes. Seed treatment with these fungi significantly reduced disease severity (3.85%–1.86%, respectively) and enhanced germination parameters [germination percentage (85.33%–86%, respectively), germination index (10.67–12.29, respectively), seedling length vigor index (86.41–109.44, respectively), and seedling weight vigor index (30.24–37.57, respectively)] compared to the control positive. Both fungi demonstrated high inhibition rates of R. solani mycelial growth (93.90%–90.46%, respectively). Greenhouse trials revealed that preventive treatments using B. bassiana and M. anisopliae increased catalase (104.40–105.52 units/mg protein/min, respectively), (4.58–5.77 units/mg protein/min, respectively), superoxide dismutase (40.65–41.74 units/mg protein/min, respectively), and polyphenol oxidase (0.539–0.559 units/mg protein/min, respectively) activities, as well as total phenolic (2.60–2.65 mg/g, respectively) and total sugar content (2.23–2.16 mg/g, respectively) in cucumber plants. Consequently, disease severity (9.51–6.99%, respectively) was reduced, and plant height (93.76–98.76 cm, respectively) increased compared to the positive control. These findings suggest that B. bassiana and M. anisopliae can enhance plant growth, stimulate plant defense mechanisms, and effectively control damping-off and root rot diseases, making them promising candidates for biological control strategies.

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