【作者】 刘海；

【导师】 林德球；

【作者基本信息】 华南师范大学 ， 植物学， 2003， 硕士

【摘要】 以香蕉为材料，研究常温下高氧（100％、60％、40％和21％ O₂）对果实采后贮藏效果、生理生化的影响，并初步从能量亏损方面探讨果实衰老的发生机制。主要结果如下： 1．高氧对香蕉果实色泽、硬度、呼吸、乙烯和渗透率的影响 高氧处理加速采后香蕉果皮的转黄，果实的软化，加快呼吸高峰和乙烯高峰的到来，增强呼吸强度以及提高乙烯释放量和细胞质膜渗透率，并且随着处理浓度增加，这种作用越显著。 2．高氧对香蕉果实氧代谢的影响 高氧处理能促进香蕉果皮或果肉中O₂^-、H₂O₂的积累，诱导果实贮藏前期SOD、POD和CAT活性。由于氧自由基和过氧化氢的大量积累超过氧化酶抗氧化能力，引发膜脂过氧化发生，MDA加速增加，从而促使果实提前衰老。而且氧浓度越高，这种作用越明显。 3．高氧对采后香蕉果实能荷的影响 100％和60％ O₂处理明显引起了果皮和果肉中ATP、ADP的含量和能荷水平的下降，而经21％O₂处理果的果皮和果肉中的ATP和ADP含量和能荷在贮藏后期虽有所下降，仍保持较高水平；各处理的AMP含量变化与各自的ATP变化相反。并从能量亏损方面讨论了高氧促使果实衰老的机制。 上述研究初步表明高氧处理引起香蕉果实衰老可能与刺激乙烯产生、呼吸加强、氧自由基清除能力下降和膜结构损伤有关；并且从能量亏损角度探讨了高氧促使果实衰老的可能作用机制。更多还原

【Abstract】 The objective of this study is to investigate the effect of high oxygen on storage life, physiology and biochemistry of posthharvest fruit. The results are as follows.1. Effects of high oxygen on color, firmness, respiratory rate, ethylene production and relative permeability of banana fruit. Exposure of banana fruit to high oxygen concentrations accelerated changes in skin color, resulted in pulp softening, increased permeability of cell membrane and shortened peaks of respiration rate and ethylene production. Furthermore, the effects were more obvious as oxygen concentrations increased.2. Effect of high oxygen on active oxygen metabolism. Application of high 02 concentrations accelerated O2 production and H2O2 accumulation, stimulated activities of SOD, POD and CAT at the early stage of storage. Due to unbalance between accumulation of superoxide anion and hydrogen peroxide and the capacity of antioxidant systems, there were enhanced lipid oxidation and a high MDA level resulting in the senescence of the fruit. Moreover, the senencence became more obvious with increased O2 concentration.3. Effect of high oxygen on energy charge. 100% O2 and 60% O2 significantly accelerated decrease in contents of ATP and ADP, and level of energy charge of fruit peel and flesh. Whereas the contents of ATP and ADP, and the level of energy charge of banana fruit exposed to 21% O2 were relatively high, with slight reduction at the late stage of storage. The change in AMP content of banana fruit exposed to four oxygen concentrations was contrary to that of ATP content.The preliminary study suggested the senescence of banana fruit caused by high O2 treatments may relate to accelerated ethylene produtction, enhanced respiration, decrease in the capacity of antioxidant systems and increased damage of membrane structure; the possible mechanism of high oxygen which caused the senescence ofbanana fruit, involving in the loss of energy charge, was discussed.更多还原