First report of Rhizoctonia solani AG-2-2 IIIB causing Rice sheath blight in China
Chengmeng Shen1, Zhenmeng Zhou2, Canting Li3
1Kunming, Yunnan Province, China; 1282785660@qq.com.
Plant Disease
|October 1, 2024
Summary
This study identifies Rhizoctonia solani AG-2-2 IIIB as a cause of rice sheath blight in China for the first time. This finding is crucial for developing new disease management strategies to protect rice crops.
Area of Science:
- Plant Pathology
- Mycology
- Agricultural Science
Background:
- Rice sheath blight, caused by Rhizoctonia solani, is a significant disease causing substantial yield losses globally.
- The disease is particularly damaging in southern China, impacting grain filling and overall crop yield.
Purpose of the Study:
- To identify the specific pathogen responsible for rice sheath blight symptoms observed in Yongfu County, Guangxi, China.
- To confirm the identity and pathogenicity of the isolated fungus, particularly its anastomosis group (AG).
Main Methods:
- Isolation and morphological characterization of fungal pathogens from symptomatic rice sheaths.
- Molecular identification using Internal Transcribed Spacer (ITS) sequencing and phylogenetic analysis.
- Pathogenicity tests on healthy rice plants to fulfill Koch's postulates.
Main Results:
- Fungal isolates exhibited morphological characteristics consistent with Rhizoctonia solani.
- Molecular analysis identified the isolates as Rhizoctonia solani AG-2-2 IIIB, with high sequence similarity to known strains.
- Inoculation tests confirmed the pathogenicity of the isolated R. solani AG-2-2 IIIB on rice plants, reproducing sheath blight symptoms.
Conclusions:
- This is the first report of Rhizoctonia solani AG-2-2 IIIB causing rice sheath blight in China.
- The identification of this specific pathogen strain provides critical information for developing targeted disease control strategies.
- This research contributes to better management practices for rice sheath blight in China.
