IB symptoms and PPO activities
In both pineapple cultivars,the percentage of fruits exhibiting IB
was significantly higher in 10 ◦C + 1 d 25 ◦C-treated fruit compared
to the 10 ◦C-treated fruit (Fig. 1A and B). IB was not found in fruits
stored at 25 ◦C for 21 d. Trad-see-thong fruit was more sensitive
to low temperatures than Pattavia fruit. At 10 ◦C, Trad-see-thong
pineapple developed IB after 7 d, while IB in Pattavia pineapple
was not observed until 14 d. IB in Trad-see-thong at 10 ◦C + 1 d
25 ◦C was two times more severe than that in Pattavia at 21 d. In Trad-see-thong, PPO activity was highest in 10 ◦C + 1 d 25 ◦Ctreated
fruit, followed by fruit stored at 10 ◦C, and was lowest
in fruit stored at 25 ◦C (Fig. 1C). However, there were no signifi-
cant differences in Pattavia between the 10 ◦C + 1 d 25 ◦C and 10 ◦C
conditions (Fig. 1D). In general, PPO activities were higher in Tradsee-thong
than in Pattavia.