| 'Wonhuwang'pear fruit(Pyrus pyrifolia (Burm.f.) Nakai.),an excellent cultivar bred in Republic of Korea, has been planted in about 10 provinces such as Inner Mongolia, Hunan etc. since being introduced into China. The wide geographical distribution means a great potencial production in China. Studies in Korea about'Wonhuwang'pear showed that core brown easily and flesh soften quickly during storage, so it is important to study its postharvest physiology, biochemistry and the storage methods before widely planting in China. In this paper, effects of different harvest time, precooling method, storage tempreture, modified atmosphere bags, 1-MCP concentration and gas composition on postharvest physiology and biochemistry of fresh'Wonhuwang'pear were systematically studied with the fruits produced in Daxing area of Beijing. The study clarified the physio-biochemical characters like type of respiration, freezing point, flesh softening and core browning, set up the the optimum harvest time and technological parameters for its storage. The main results are showed as follow:1.'Wonhuwang'pear showed small respiration peak when storaged at room temperature, indicated that it belonges to climacteric fruit. The respiration rate was 10～20mgCO2/(kg.h), ethylene production≤0.15μl/(kg.h).2.'Wonhuwang'pear fruit which harvested in suitable maturity remained good qulity without flesh browning, and kept slight core browning caused by PPO during storage. Late harvesting, Chilling injury, high CO2 concentration and long time storage at high temperature (≧5℃) increased core browning. The flesh firmness was significantly negative correlative with the activity of amylase and cellulose in the early storage, and significantly negative correlation between flesh firmness and ethanol production was found in the late storage. The correlation coefficient was -0.907*, -0.985* and -0.902*, respectively(Pearson, P≤0.05, one tailed).3. The suitable harvesting index based on the maturity of'Wonhuwang'pear fruit in Beijing: 135d DAFB, flesh firmness 7.42kg/cm2, SSC 11.2%, seeds color index 0.62. Several days earlier for harvesting was suggested.4. Gradual cooling (reducing 1℃per day from 10℃to 0℃) was adviced for precooling of'Wonhuwang'pear fruit, which was obviously prior to fast cooling (store at 0℃directly after harvest) in remaining higher flesh firmness, SSC, TA ,Vc and fresh fruit-stem.5. Freezing point of'Wonhuwang'pear was about﹣1.7℃, chilling injury happened at﹣1.5℃～﹣1.0℃, suitable storage temperature was 0℃and 1.5℃, in this case, it could be storaged for less than 140 days with good quality.6. For long storage of'Wonhuwang'pear, the suitable gas composition was 3% O2 plus 1%CO2, it inhibited ethylene production during late storage, remained good color of skin and kept fruit stem fresh, reduced amylase activity at early stage, restrained core browning and sustained high total phenolics content and lower PPO activity of core. In the condition of 3%O2, fruits were injured by high CO2 concentration (≥3%CO2) with higher core browning incidence and bitter flavor.7. The suitable modified atmosphere packaging for'Wonhuwang'pear fruit storage was 0.02mmPE closed bags, and the maximum concentration of CO2 was 2.4% with good quality of fruits. The concentration of CO2 in 0.04mmPVC closed bags was 3.2%～4.2%% and the flesh browning was not found, but abnormal flavor appeared.8. The treatment of 1-MCP was effective at some extent on storage of'Wonhuwang'pear. The concentration of 0.5μl/L 1-MCP plus 0.02mm PE bags was supposed to be stored for 180 days, and 1.0μl/L1-MCP plus 5℃could store less than 60 days. While 1.0μl/L 1-MCP plus 0℃or 1.5℃just delayed stem browning without other positive action.
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