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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sugarbeet and Potato Research » Research » Research Project #432531

Research Project: Improved Cercospora Leaf Spot Management for Sugarbeet Using Molecular Technologies

Location: Sugarbeet and Potato Research

Project Number: 3060-22000-049-000-D
Project Type: In-House Appropriated

Start Date: Mar 14, 2017
End Date: Jun 22, 2018

Objective:
Objective 1: Develop genomic and transcriptomic resources to better identify fungicide-resistant and fungicide-sensitive strains of Cercospora beticola. Sub-objective 1.A: Harvest Cercospora beticola isolates before and after fungicide treatment and determine fungicide resistance data for each strain. Sub-objective 1.B: Use a genome wide association study (GWAS) to identify genomic regions associated with fungicide resistance in Cercospora beticola. Objective 2: Facilitate the development of improved sugarbeet disease resistance to C. beticola through comparative genomics, transcriptomics, and pathogenicity studies on strains isolated from wild sea beet and cultivated sugarbeet germplasm. Sub-objective 2.A: Investigate patterns of genome evolution and host-adaptation by sequencing genomes of Cercospora beticola strains isolated from sea beet and sugarbeet. Sub-objective 2.B: Assess virulence of sea beet- and sugarbeet-adapted strains of Cercospora beticola Objective 3: Develop improved sugarbeet resistance to C. beticola using effector-based screening. Sub-objective 3.A: Characterize novel candidate cercosporin auto-resistance genes in the cercosporin biosynthesis pathway. Sub-objective 3.B: Characterize novel candidate cercosporin biosynthesis gene CBET3_00842.

Approach:
The $3 billion U.S. sugarbeet industry is the primary supplier of domestic sucrose. Sugarbeet provides an important source of stable, environmentally safe, and low-cost dietary carbohydrate to the public. In addition, beet sugar production and allied industries are an important employment source regionally and nationally. Yield and quality losses are primarily a result of disease. These losses, in conjunction with expenses associated with pesticide application, cost the U.S. sugarbeet industry up to $150 million annually. The most important foliar disease of sugarbeet worldwide is Cercospora leaf spot, caused by the fungus Cercospora beticola (Cb). Despite the agricultural importance of this pathogen, stable genetic resistance does not currently exist and disease is primarily managed through application of fungicides. Consequently, fungicide resistance is a growing concern for sugarbeet growers. Critical information is lacking on the basic biology of the sugarbeet/Cb interaction and the molecular basis of fungicide resistance. The goals of this project are to identify genetic components underlying fungicide resistance (Objective 1), uncover effectors critical for disease development by comparative genomics and pathogenicity analysis of Cb strains harvested from sugarbeet and its progenitor sea beet (Objective 2), and characterization of newly identified genes important for cercosporin biosynthesis and auto-resistance (Objective 3). This project utilizes state-of-the-art technology with results that will be utilized by all sectors of the sugarbeet industry from seed producers to growers to processors. The concepts and discoveries generated by this research will lead to a more thorough understanding of sugarbeet pathology as well as host-pathogen interactions that negatively affect worldwide production agriculture.