Rapid Determination of Rice Cultivar Responses to the Sheath Blight Pathogen Rhizoctonia solani Using a Micro-Chamber...

Area of Science:

• Plant Pathology
• Agronomy
• Genetics

Background:

• Sheath blight, caused by Rhizoctonia solani, leads to substantial rice yield losses globally.
• Lack of a reliable greenhouse screening method hinders resistance studies and breeding efforts.

Purpose of the Study:

• To develop and validate a standardized micro-chamber screening method for quantifying rice resistance to sheath blight.

Main Methods:

• Five rice cultivars were tested in a micro-chamber system under controlled greenhouse conditions.
• Inoculation involved Rhizoctonia solani mycelium plugs on three- to four-leaf stage seedlings.
• Standard cultivars (Jasmine 85, Lemont) were used, and results were compared with field evaluations.

Main Results:

• The micro-chamber method provided consistent disease ratings across three test locations.
• Greenhouse ratings correlated well with established field evaluations for resistance levels.
• Relative disease reactions of tested cultivars were reliably determined.

Conclusions:

• The micro-chamber screening method is effective for accurately quantifying rice resistance to sheath blight under controlled conditions.
• This method can accelerate the selection process for breeding improved sheath blight-resistant rice cultivars.