Applying Real-Time Quantitative PCR to Fusarium Crown Rot of Wheat

Area of Science:

• Plant Pathology
• Molecular Biology
• Agricultural Science

Background:

• Fusarium crown rot (FCR) causes significant global wheat losses, primarily from Fusarium culmorum and F. pseudograminearum in Montana.
• A real-time quantitative PCR (QPCR) assay targeting the trichodiene synthase (tri5) gene was recently developed for FCR detection.

Purpose of the Study:

• To evaluate the effectiveness of the QPCR assay for assessing FCR severity in field-grown wheat.
• To correlate QPCR-based Fusarium DNA quantification with traditional disease severity scores and grain yield.

Main Methods:

• Wheat plots (spring and durum) were inoculated with F. pseudograminearum and grown under rain-fed conditions over two years (2004-2005).
• Plant samples were collected pre-harvest for Disease Severity Scores (DSS) and analyzed using QPCR to quantify Fusarium DNA.
• Statistical analyses correlated DSS and Fusarium DNA quantities with each other and with grain yield.

Main Results:

• Fusarium DNA quantities positively correlated with DSS in all cultivars in 2004 and durum in 2005.
• In 2004, grain yields for spring wheat cultivars were negatively correlated with Fusarium DNA quantities.
• Both DSS and Fusarium DNA quantification showed comparable predictive ability for yield reduction when negatively correlated with yield.

Conclusions:

• The developed QPCR assay is a reliable and effective tool for measuring FCR severity in wheat under field conditions.
• QPCR provides quantitative data that complements traditional disease assessment and aids in predicting yield impacts.
• This assay can be utilized in future wheat breeding and disease management strategies.