2007 Annual Report 1a.Objectives (from AD-416) 1) Continue to apply the tested ethylene molecular markers for ACS1 and AC01 in segregation populations in the WSU Apple Breeding Program to select for low ethylene production.. 2)Test and apply a reported apple fruit peel red color marker in the existing WSU segregation population for selection of red color development capacity.. 3)Identify potential candidage genes regulating apple firmness and crispness.. 4)Elucidate relationships between expression of apple AAT (alcohol acyl transferase) genes and cultivar differences in volatile ester production. 1b.Approach (from AD-416) Genomic, genetic and physiological methods will be employed to identify the genes and pathways regulating apple fruit firmness and crispness, using existing apple cultivars exhibiting distinct phenotype on these traits. Further validation and detailed functional analysis will be conducted by RT-PCR, real-time PCR, and/or RNA gel blot analysis. Candidate gene approach will be used to examine the alcohol acyl transferase gene family to understand the contribution of each member to the varietal difference on volatile ester production from ripening apple fruit. Current available molecular markers on ethylene production and peel red color will be applied in current apple breeding project. 3.Progress Report This project received funding on 7/23/2007. There is no progress to report at this time as research has not been started.