Location: Plant Genetic Resources Unit (PGRU)
Project Number: 8060-21000-029-02-R
Project Type: Reimbursable Cooperative Agreement
Start Date: Oct 1, 2016
End Date: Aug 31, 2020
1. Accelerate critical evaluations of new apple rootstock genotype adaptability to important and diverse environments, pests, production systems and propagation systems including a) climatic adaptations, b) abiotic soil adaptations, c) biotic soil adaptations and pests, d) nutrient uptake efficiency, and e) impact on fruit disorders. 2. Accelerate the development of new improved apple rootstock genotypes with critical traits for advancing tree fruit production. 3. Evaluate the economic and sociological impacts of adopting new apple rootstocks for fruit production including impacts on the environment and on labor. 4. Initiate rapid and effective extension and outreach efforts to disseminate objective information about new apple rootstock traits and their successful management in competitive production systems.
Approach Geneva: This part of the project connects with the activities under Objectives 1.a) biotic soil adaptations and pests, 1.b) abiotic soil adaptations, and 1.c) nutrient uptake efficiency to enable the discoveries on the nature and inheritance of nutrient absorption, interaction with soil biota and interaction with soil abiotic conditions to produce horticulturally superior germplasm with commercial potential. This will be accomplished by phenotyping replicate trees made with rootstock clones of segregating populations that have been genotyped. There are three rootstock breeding populations that will be targeted: progenies from Ottawa 3 x Robusta 5, G.935 x B.9 and G.41 x M. sieversii selection each having more than 150 individuals. These populations have been or will be genotyped with the Illumina RosBREED 9K SNP chip or the FruitBreedomics 20K SNP chip. Phenotypic data resulting from activities in Objective 1 will be combined with genotypic data developed in-house in Objective 2 and with the aid of quantitative trait analysis software (MapQTL 6 or SAS JMP genomics) we will identify quantitative trait loci that modulate the traits measured. In addition a set of elite breeding material that has passed the standards for yield efficiency, productivity, resistance to fire blight and phytophthora will be propagated by soft wood cuttings, tissue culture or stool bed and derived rooted liners will be propagated and sent to PDs in charge of experiments in objective 2 to be combined with material from other breeding programs. Performance data from these experiments will be used to validate the robustness of molecular markers developed in the program and the identification of new parents for the next generation of apple rootstocks.