2013 Annual Report
1a.Objectives (from AD-416):
Objective 1: Evaluate, characterize, and utilize available sugarbeet genetic resources and ascertain the diversity (genetic, proteomic, morphological, and pathogenic) within and among sugarbeet and sugarbeet pathogen populations to fulfill the objectives below. This objective is an important part of the ARS NPGS Beta germplasm collection, which is available to public and private breeders and geneticists.
Sub-objective 1a: Determine the spatial scale of genetic differentiation among populations of B. nana.
Objective 2: Characterize the interaction of major sugarbeet pathogens (esp. Beet necrotic yellow vein virus, Cercospora beticola, Rhizoctonia solani, and Fusarium oxysporum) with sugarbeet.
Sub-Objective 2a: Apply proteomics protocols to understand Beet necrotic yellow vein virus-sugar beet interactions.
Sub-Objective 2b: Using comparative proteomics, determine the degree of conservation of defense response against a variety of Fusarium spp.
Sub-Objective 2c: Determine role of ubiquitination and the proteosome pathway in activation of plant defense.
Objective 3: Develop and distribute enhanced germplasm with novel stress resistance genes.
1b.Approach (from AD-416):
A multidisciplinary approach combining traditional genetics, molecular biology, and biochemistry will characterize variation among sugarbeet wild relatives and cultivated beets. Understanding the diversity within the NPGS Beta PI collection is necessary to both intelligently manage and utilize the germplasm stored in this collection. Understanding of the diversity contained in our commercial lines is necessary to most effectively introduce new diversity into them. Understanding the genetic variability of pathogen populations is extremely important to maintaining durable host plant resistance. The same classical and molecular tools will be used to gain the knowledge of genetic diversity in the pathogens, which is critical for selecting the number and pathotype of organisms to use in resistance screening.
This multidisciplinary approach combining traditional genetics, molecular biology, and biochemistry will be used for identification of key genes or proteins involved in the sugar beet pathogen interaction. Characterization using varied techniques provides a better understanding of plant defense against disease and identifies candidate genes and novel sources of resistance to move into sugar beet germplasm. Furthermore, this greater knowledge of sugar beet pathogen interaction opens up avenues for creating novel selection tools, including exploitation of polymorphisms and use of biomarkers. The same analyses can be used to understand and better manage pathogens of sugar beet, creating novel, more effective disease control strategies.
The basis of the breeding program is the formation of long range breeding populations through the introgression of resistant germplasm from “exotic” sources of the primary Beta germplasm pool (Beta vulgaris ssp. maritima, fodder beet, table beet, Swiss chard, foreign sugar beet landraces from the PI collection, etc.). This breeding scheme provides great flexibility to accommodate the genetic background of the germplasm and the disease resistances being chosen. The development of breeding populations will be accomplished using methods that produce genetically defined sub populations, which are useful for resistance gene mapping, marker development, exploring sugarbeet-pathogen interactions, and gene discovery.
5402-21220-008-00D is a bridging project. Please see the final report for 5402-21220-007-00D.