ศูนย์นวัตกรรมเทคโนโลยีหลังการเก็บเกี่ยว

Polymines and salicylic acid metabolism during citrus fruit maturation and their effects on fruit storage

Yusheng Zheng , Quiming Zhang

Dept. of Botany and Plant Sciences, University of California at Riverside, Riverside, CA 92521, U S A

2002

บทคัดย่อ

Seven-year-old Ponkan trees (Citrus reticulata) on trifoliate rootstocks (Poncirus triforliata) were usedto monitor the changes of endogenous polyamines (Pas) and salicylic acid (SA) during fruit maturation, and to study their effects on postharvest storage life.The results showed that endogenous levels of free PAs and SA peaked in October at a maximum amount of 1,223 nmol g^-1 FW and 2, 150 ng g^-1 FW, respectively.However, their contents started to drop gradually during fruit ripening.Fruit ripening.Fruits harvested in December were dipped with solutions of 100 mg L-1 putrescine (Put), spermiding (Spd), and 400 mg L^-1 SA for 2-3 min, and thenstored for a period of 3 months.It was shown that external application of above Pas and SA elevated endogenous levels of free Pas and SA, and the postharvest storage life was improved for Ponkan fruits.Except Put, all treatments resulted in the higher levels of endogenous Pas and SA in the storage fruits compared to the control.Analysis showed that treated fruits only had 2.0-6.4 % decay during 3 months storage, 2.0% for SA, 3.5% for Spm, 4.0% for Spd, and 6.4% for Put treatment, respectively.Weight loss for the treated fruits were 3.0-5.2%, 3.0% for SA and Spd, and 5.2% for Put treatment, respectively.As a comparison, control fruit showed 13.5% decay and 11.0% weight loss during 3 months period of storage.Therefore, study has demonstrated that application of external Pas and SA could effectively elevate endogenous Pas and SA level, which has led to the improvement of fruit storage life.Among all treatments, SA and Spm treatments were show the best, followed by the Spd and Put treatment.