采后茉莉酸甲酯处理对蓝莓果实抗病性的影响

Effect of Postharvest Methyl Jasmonate Treatment on Blueberry Fruit Disease Resistance during Storage

目的研究简易自发气调包装及不同浓度茉莉酸甲酯(MeJA)处理对采后蓝莓果实抗性的影响。方法分别用浓度为0.15,0.3 mmol/L的MeJA以及去离子水浸泡蓝莓果实,时间均为10 min,将取出的果实晾干、预冷,装入厚度为0.0294 mm的聚乙烯简易自发气调包装袋中,于1℃下贮藏,以15 d为1周期对蓝莓呼吸代谢及抗性相关指标进行测定,即袋内CO_2和O_2浓度,以及果实亮度、感官评定、呼吸速率、硬度、腐烂率、pH值、可溶性固形物(SSC)含量、苯丙氨酸解氨酶(PAL)活性、多酚氧化酶(PPO)活性、过氧化物酶(POD)活性、木质素含量等。结果 MeJA处理可有效保持包装袋内适宜的CO_2和O_2浓度,并可减缓果实硬度、亮度的下降,抑制果实呼吸速率、pH值及SSC含量的上升,提高果实木质素含量,降低果实腐烂率,显著提高PAL,PPO,POD等抗性相关酶活性(P<0.05)。结论简易自发气调包装结合MeJA处理可通过抑制呼吸代谢、提高苯丙烷代谢及抗氧化酶活性,从而诱导采后蓝莓果实抗性的产生,保持采后果实品质。在2种浓度的MeJA处理中,浓度为0.15 mmol/L的处理效果最好。

The work aims to study the effects of treatment by simple spontaneous modified atmosphere packaging（S-MAP） and methyl jasmonate（MeJA） of different concentrations on the postharvest blueberry fruit resistance. Blueberry fruit was immersed in 0.15 and 0.3 mmol/L MeJA and deionized water for 10 min, respectively; then, the fruit was air-dried, precooled, filled into polyethylene S-MAP with a thickness of 0.0294 mm and stored at 1 ℃. The indexes of respiratory metabolism and resistance of blueberry were determined in a period of 15 d, including the concentration of CO2 and O2 in the S-MAP, fruit brightness, sensory evaluation, respiration rate, firmness, decay rate, pH, soluble id content（SSC）, phenylalanine ammonia-lyase（PAL） activity, polyphenol oxidase（PPO） activity, peroxidase（POD） activity and lignin content. MeJA treatment could effectively maintain the appropriate concentration of CO2 and O2 in the bag, slow down the decline of fruit firmness and brightness, inhibit the rise of respiration rate, p H value and SSC, increase the lignin content, reduce the decay rate, and significantly improve the activities（P0.05） of enzymes related to the resistance, such as PAL, PPO and POD. S-MAP combined with MeJA treatments can induce the generation of the fruit resistance and maintain the quality of postharvest fruits by inhibiting the respiratory metabolism, and increasing the metabolism of phenylpropane and the activity of antioxidant enzyme. During the MeJA treatments of two concentrations, the treatment effect is the best when theh concentration is 0.15 mmol/L.