Quantifying efficiency and accuracy in the Washington State University apple breeding program

The Washington State University Apple Breeding Program just passed its 20th anniversary, released its third new variety and moved under new direction with breeder Kate Evans. The major program goal is to release a portfolio of new and improved cultivars suited to production in central Washington. Improved cultivars should have exceptional storability, to compliment the state's unrivaled long term cold storage facilities, while engendering an exceptional consumer experience. Apple breeding is a long and expensive process and therefore exploring how well the program meets its goal---releasing the best new cultivars---can validate the expenditures of the program while also potentially finding methods that would improve discovery rate and cost efficiency. The three main subprojects and conclusions are as follows: 1) Quantify moldy core susceptibility in currently available germplasm to inform crossing decisions and discover predisposing characteristics to inform culling decisions. Factors that predispose selections for moldy core were confirmed and appear heritable. 2) Quantify fire blight resistance in wild relative Malus sieversii to further inform crossing decisions and provide data for future association mapping. Multiple M. sieversii accessions were found to be resistant and will be used in 2016 as parents. 3) Analyze the cost structure of the current breeding program and the accuracy of trait evaluations in the replicated data collection phase of the program to explore the most efficient design structure for identifying elite selections. An alternative design that would allow more selections to be evaluated in that phase was proposed and is under consideration for the 2016 planting.