ผลของการใช้สาร n - propyl dihydrojasmanate และ กรด abscisic ภายหลังการเก็บเกี่ยวต่อการลดการเกิดอารการสะท้านหนาวของผลพลับ (Diospyros kaki cv. 'Nishimurawase' เก็บรักษาที่อุณหภูมิต่ำ
Effect of n-Propyl Oihydrojasmonate and Abscisic Acid Application on Reducing Chilling Injury of Persimmon Fruit (Diospyros kaki cv. 'Nishimurawase') When Stored at Low Temperatures
Abstract:
Chilling injury (CI) occurred on plants when stored at low temperature, indicated by cell
damage. CI can be generated from oxidative stress which produces reactive oxygen species
(ROS). So, a better understanding on the physiological and biochemical responses of
persimmon fruit to chilling injury can help in development of postharvest techniques to
alleviate this problem. In this study, persimmon fruit (Diospyros kaki cv. 'Nishimurawase')
showed evident of CI symptoms at OC, while the optimum storage temperature was 4C
which delayed ripening and maintained the quality during storage. Plant growth regulators
(PGRs) of n-propyl dihydrojasmonate (PDl) and abscisic acid (ABA) were applied to
persimmon fruit to investigate their effectes on oxygen radical scavenging enzymes and
chilling injury (CI) development during low temperature storage. Fruit at commercial
maturity were thoroughly sprayed with PDl or ABA at 250 ppm, and then stored at 4 and
O?C for 8 weeks. Thereafter, they were transferred to 25C for 2 days to ripen. Both POl
and ABA induced ethylene production in treated fruit. PDl treatment effectively reduced
CI symptoms as evidenced by less-grayish peel browning and flesh softening. The PDl
promoted the persimmon ripening and increased the caroteniod content, glucose content
and fructose content higher than that of control treatment. However, color changes (hue
angles), weight loss, firmness and chlorophyll content of POl treatments were lower than
control treatment. Polyphenol oxidase (PPO) activity in PDJ treated fruit was lower than in
the control, while the vitamin C content of PDJ treated fruit were higher than that of
control. Furthermore, PDJ treatment was shown to maintain ace of electrolyte leakage as
indicated by reducing lipoxygenase (LOX) activity which resulted in a decrease of
malondialdehyde (MDA) content compared to control. The activites of oxygen radical
scavenging enzymes, namely superoxide dismutase (SOD), peroxidase (POD), catalase
(CAT) and ascorbate peroxidase (APX) in the PDJ treatment were higher than those in
control fruit. The results indicated that PDJ induced free radicals scavenging enzymes of
antioxidant systems, resulting reduced CI symptoms in persimmon fruit. The results
suggest that PDJ may play a role in the regulation of ripening and senescence of
persimmon fruit.