Phenotypes and ethylene production in different developmental timepoints of “Gala” and “Ralls Janet”. A, Phenotypes and B, Ethylene production at different developmental timepoints of “Ralls Janet” and “Gala” apple fruit (T1: timepoint 1; T2: timepoint 2 T3: timepoint 3; T4: timepoint 4; T5: timepoint 5; T peak: timepoint of peak ethylene production of “Gala”). Scale bar = 1 cm. Asterisks indicate a statistically significant difference (*P <0.05; **P <0.01; ***P <0.001), as determined by a one-way analysis of variance (ANOVA). Error bars indicate ±sd of three replicates. The images of (A) were digitally extracted for comparison.