Postharvest changes in abscisic acid levels in flesh tissue and seeds of Jonathan apples susceptible to storage breakdown

Summary

Analysis of fruit and seed samples after periods from three to 16 weeks of storage showed that the abscisic acid level in the flesh was maximal early in storage, declining during 16 weeks at —1°C. A direct correlation between ABA level and later breakdown incidence was present early in storage, the correlation being greatest after five weeks, much earlier than the appearance of visible symptoms. In the seeds ABA was maximal after three weeks and then declined, being undetectable by 12 weeks. However, there was no significant correlation between seed ABA content and breakdown incidence. When early seed extracts were injected into fruit, breakdown incidence increased but the increase was unrelated to the fruit source of the seeds.