The crown plays an important role in maintaining quality of harvested pineapple

Abstract

Pineapple is a unique fruit partly because it has a beautiful crown and consumers around the world regard the crown as an integral part of pineapple fruit. However, farmers in some countries detach the crown at harvest and use it for propagation. It is not clear whether the detachment of crown affects quality of harvested pineapple. This study shows that decrowning aggravated internal browning by 55.2% and reduced SSC/TA ratio by 2.2, following 9-d storage, suggesting that decrowning deteriorated quality of the flesh and shortened shelf-life of fruit. Furthermore, decrowning increased reactive oxygen species (ROS), malondialdehyde (MDA), and phenolics levels, and upregulated polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) gene expression and activity, suggesting keeping crown intact prevented ROS generation and lipid peroxidation, and inhibiting phenolics biosynthesis and oxidation. Moreover, decrowning increased endogenous GAs(GA1 and GA4) and decreased endogenous ABA in pineapple tissues, suggesting crown is important for keeping balance between GAs and ABA. Exogenous application of ABA inhibited IB in pineapple with intact crown more effectively than in decrowned one, ABA application to crown only controlled IB as effectively as to both crown and fruit, and decrowning following ABA application to crown significantly compromised the efficacy. These suggest that the crown is the main source of endogenous ABA and that IB control depends on continuous supply of ABA from the crown. This study provides possibility for effectively controlling IB.