Comparison of transcriptomes in five varieties of citrus fruit

To identify genes associated with citrus peel development and manifestation of peel disorders, we analyzed flavedo, albedo and juice sac tissues from five types of citrus fruit including, mandarin orange, navel orange, valencia orange, grapefruit and lemon. Mature, healthy fruits of five different citrus cultivars (“Valencia” and “Navel” orange [Citrus sinensis], mandarin [Citrus reticulata], lemon [Citrus × limon], grapefruit [Citrus × paradisi]) were purchased from a food market located in Davis, CA, USA. For all five types of fruit, three tissues (flavedo, albedo, and juice sacs) were compared separately. Each of the three tissues from each of the five types of fruit were sampled in three biological replicates, for a total of 45 samples. Samples were prepared from a 1 cm-thick equatorial disc and four sections (N, S, E, and W) were cut. Each section of flavedo, albedo, and juice sac tissue was dissected. gene expression variation underlying quality trait, different genotypes