Location: Plant Genetic Resources Unit (PGRU)
Project Number: 8060-21000-029-000-D
Project Type: In-House Appropriated
Start Date: Mar 29, 2018
End Date: Mar 28, 2023
Objective 1: Develop and release improved apple rootstocks by leveraging advances in marker assisted breeding, including construction of genetic maps, establishing trait associations, gene discovery for important rootstock traits (dwarfing, early bearing, yield efficient, fire blight resistant), and screening for novel alleles for important rootstock traits. Sub objective 1A: Perform all breeding and evaluation stages involved in the 15-30 year process (timeline depending on intensity of phenotyping and need to fast-track) of developing new rootstocks with the assistance of recently developed breeding tools, such as high throughput phenotyping and marker-assisted breeding. Sub-objective 1B: Identify and characterize novel germplasm, genes, alleles and trait loci through quantitative trait analyses leveraging new genetic-physical maps. Objective 2: Identify and dissect important rootstock traits that modify gene activity in the scion, toward enhancing drought tolerance, tree architecture, propagation by nurseries, root growth and physiology, nutrient use efficiency, and disease resistance; incorporate this knowledge into breeding and selection protocols. Sub-objective 2A: Identify components of rootstock induced traits that modify gene expression and metabolic/physiological profiles of grafted scions to increase tolerance to abiotic stresses, improve fruit quality and storability, increase tree productivity, disease resistance and nutrient use efficiency. Sub-objective 2B: Validate relationships between trait components and overall apple tree performance in different rootstock-scion combinations and incorporate new knowledge into breeding and selection protocols.
The objectives of this project will be met by applying a combination of conventional breeding techniques and marker assisted breeding to select for improved rootstocks. The project will also leverage the use of aeroponics to study components of root traits that aid in nutrient uptake and water use efficiency by monitoring gene expression and other metabolic componds in apple roots.