Alleviation of black root rot symptoms and alteration of strawberry growth via modulating physiological and biochemical mechanisms using Trichoderma viride and Bacillus subtilis

• Published in: European journal of plant pathology Vol. 167; no. 2; pp. 235 - 250
• Main Authors: Abied, Mohamed A. E., Khalil, Mohamed I. I., Awad, Mohamed F., Youssef, Sahar A.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-10-2023; Springer Nature B.V
• Subjects: Agriculture; Bacillus subtilis; Bioassays; Biomedical and Life Sciences; Black root; Catalase; Cell membranes; Ecology; Enzymatic activity; Flowers & plants; Fruits; Fungi; Greenhouses; Hydrogen peroxide; Life Sciences; Lipid peroxidation; Lipids; Microorganisms; Parameters; Pathogens; Peroxidation; Plant diseases; Plant growth; Plant Pathology; Plant Sciences; Root rot; Signs and symptoms; Soil amendment; Soils; Strawberries; Superoxide dismutase; Trichoderma viride; Black root rot disease; Biotic stress; Antioxidant enzymes
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-023-02697-w

The effectiveness of
Trichoderma viride
and
Ba
cillus subtilis
to protect strawberry against black root rot disease under the greenhouse and field conditions was investigated. In
in vitro
bioassays, the two microorganisms exhibited strong capabilities to antagonize the pathogen
Rhizoctonia fragariae.
Soil amendment with
T. viride
at rate 50 ml/ plant (1 x 10
7
/ ml) conidial spore and
B. subtilis
at rate 50 ml/ plant (1 x 10
8
/ ml cfu) separately or in combination ameliorated the disease symptoms, enhanced plant growth parameters reaching 1.2 and 1.6 fold for shoot and root growth in greenhouse, whereas the growth enhancement reached 1.2 and 1.5 fold for shoot and roots growth in the field. Consequently, fruit numbers was increased by 2 and 4 fold for plants grown in the greenhouse and fields , respectively. Further biochemical evaluation revealed a substantial increase in ethylene signals at day 2 and 4 and remained high at day 7 after treatment under greenhouse and field conditions, whereas the accumulation of hydrogen peroxide (H
2
O
2
) was decreased at day 2 after treatment compared with pathogen infected plants. Furthermore,
T. viride
and
B. subtilis
application ameliorated ion leakage damage in infected plants whereas lipid peroxidation decreased significantly resulting in maintaining cell membrane integrity. In addition, examination of the capability of the two microorganisms to enhance the antioxidant enzymatic activities exhibited a significant increase of superoxide dismutase (SOD) and catalase (CAT) activities on day 4, 5 and 6 after treatments. These results suggest that the application of
T. viride
and
B. subtilis
as soil amendment provides a significant protection against
R. fragariae
and improves plant growth parameters and fruit numbers. However, the combination of the two bioagents did not provide additional protection.