The Main Physiological Changes And Regulation Of Loquat And Melting Peach Fruit After Harvest

In this study, the effects of different temperatures on postharvest loquat (Eriobotryajaponica Lindl. cv. Dahongpao) fruit storage were studied. During storage at 20癈, the ethylene biosynthesis of loquat fruit followed typical non-climacteric pattern, the LOX activity, O2- accumulation and PAL activity showed climacteric changes, tissue relative electric conductivity kept increasing, the fruit firmness tended to arise, fruit flesh became rough, juiceless and showed characters of lignification. Lower temperature storage at 1 significantly inhibited the fruit ethylene biosynthesis, the LOX and PAL activity, reduced O2 accumulation, and put off the course of fruit ripening and senescence, whereas, promoted the increase of tissue relative electric conductivity and fruit firmness.It was found that 1-MCP treatments on loquat markedly inhibited the enzyme activity of PAL, LOX and ACO, the O2- production rate, and ethylene production, slowed up the tissue lignification and kept high fruit quality. The optimal concentration was 5 l/L.During the ripening and senescence of 'Yulu' (Prunus persica (L.) Batsch) melting peach fruit, the endogenous SA level decreased, the activity of CDPK reduced, moreover, LOX and PAL activity, the O2- production rate, the ACS and ACO activities and ethylene production all showed climacteric changes. The fruit firmness decreased rapidly, tissue relative electric conductivity elevated continuously.An experiment on 1.0 mmol/L (pH 3.5) ASA treated peach fruit at 20 was carried out to investigate the effects and mechanism on fruit ripening. The results showed that ASA treated tissue kept higher SA level and CDPK activity, while the activities of LOX , AOS, ACS , ACO and ethylene production were inhibited, ASA treatment helped maintain higher fruit firmness and cell membrane integrity, thus delayed the fruit ripening and senescence.