Enabling Breeding for Improved Storability in Apple: Characterizing Genetic Loci Associated with Soft Scald and Soggy Breakdown
Soft scald (SS) and soggy breakdown (SB) are physiological storage disorders in apple (Malus domestica Borkh.). These storage disorders can be particularly problematic because they develop after apples have been harvested and put into storage. In a previous study, two genetic regions associated with SS and SB were identified on linkage groups 2 (LG2) and LG16. LG2 was characterized and a haplotype associated with high disorder incidence (HDI) was identified. This study aimed to characterize the effect of LG16 locus and its interaction with the locus LG2. The results of this research supported the findings of previous research. However, low overall disorder development and poor fruiting, made it difficult to fully characterize the effects of LG16 on SS and SB. Two copies of HDI at LG2 were associated with high relative SS and SB. At LG16, the highest mean SS and SB was observed for individuals that inherited H03 from MonArk. When LG2 and LG16 loci were considered together, the highest mean incidence of SS and SB was observed for individuals that had two copies of HDI on LG2 and had haplotype H03 inherited from MonArk on LG16.The large variation in SS and SB proportion due to small sample sizes made it challenging to estimate statistical significance among haplotype groups. Information from this study can be utilized for more informed breeding efforts and will contribute to known information about haplotype effects at these loci.