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ARS Home » Southeast Area » Poplarville, Mississippi » Southern Horticultural Research » Research » Research Project #425102

Research Project: Small Fruit and Ornamental Genetic Research for the Mid-South

Location: Southern Horticultural Research

Project Number: 6062-21000-009-000-D
Project Type: In-House Appropriated

Start Date: Jul 2, 2013
End Date: Feb 5, 2018

The long-term objective of this project is to develop improved germplasm for woody ornamental and small fruit crops adapted to the Gulf Coast Region where the effects of both biotic and abiotic stresses are exacerbated by frequent weather extremes. Objective 1. Design and apply phenotyping methods to identify and measure traits associated with environmental tolerance in southern-adapted small fruit and woody ornamental crops, especially in underutilized and native germplasm that can be incorporated into existing breeding programs. Objective 2. Identify markers and/or genes that are associated with environmental tolerance in breeding populations and evaluate indirect selection strategies for drought, heat, and poor soil tolerance designed to improve the efficiency and accuracy of selection during breeding. Objective 3. Design and test high throughput sequencing methods to uncover genes differentially expressed in response to environmental stress. Objective 4: Accelerate the genetic improvement and cultivar development for small fruit and woody ornamental genera with the genetic resources developed in Objectives 1, 2, and 3.

Understanding the genetic basis for plant tolerance to environmental stress is critical to protecting agriculture productivity in the U.S. and worldwide. The Thad Cochran Southern Horticultural Laboratory will lead research on the vulnerability of specialty crops to drought, heat, flood and poor soils, and to develop tools to incorporate selection for superior environmental tolerance into existing breeding programs. Scientists will develop innovative and rigorous phenotyping to more quickly and efficiently quantify traits associated with drought and poor mineral soil tolerance in small fruit and woody ornamental crops. Germplasm will be evaluated by modification and refinement of greenhouse methods. Initial focus will be on improved selection in southern adapted blueberry germplasm including existing cultivars. Subsequent efforts will focus on selection criteria for seedling populations to produce criteria directly applicable to southern blueberry breeders. Proposed research is designed to connect phenotypes associated with stress tolerance to specific genotypes allowing rapid, precise selection of traits in existing breeding lines using indirect selection by molecular markers. Molecular studies will also contribute significantly to understanding the genetic basis for environmental tolerance traits and the inheritance and segregation of these traits in existing conventional breeding programs for blueberry. Scientists will also identify novel genes and gene expression patterns associated with severe stress and recovery in native plants exhibiting superior environmental tolerance to drought and flooding to increase our understanding of existing abiotic stress tolerance models. Initial experiments will use Pityopsis ruthii, which is an endangered, native plant that exhibits extreme environmental tolerance. Results from phenotyping, genotyping, and gene expression studies will be incorporated into our conventional breeding programs to enhance efficiency and to advance development and application of new breeding tools. Blueberry parents and seedling populations at all stages of development are available for phenotype, marker and genotype studies as well as breeding for new, improved cultivars. An extensive blueberry species and cultivar collection is also available on site along with breeding materials from collaborating universities and the National Clonal Germplasm Repository.