炭疽病菌侵染对荔枝果实生理生化变化的影响

Effects of Colletotrichum gloeosporioides Infection on Physiological and Biochemical Changes of Litchi Fruit

本研究测定了荔枝果实人工接种炭疽病菌后呼吸速率、乙烯释放量的变化和果皮氧化、过氧化作用以及与酚类代谢有关的几种酶活性的变化。结果表明,接种炭疽病菌的荔枝果实呼吸速率和乙烯释放量显著增高,果皮活性氧()产生速率和丙二醛(MDA)含量显著增加,超氧化物歧化酶(SOD)活性显著降低,过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨酸解氨酶(PAL)活性显著增高。说明炭疽病菌的侵染可导致荔枝果实呼吸速率和乙烯释放量的增高,加速荔枝果皮氧化和过氧化进程,并诱导荔枝果皮PPO、POD、PAL活性增高,是加速采收后荔枝果实衰老、褐变、腐烂的一个重要原因。

Changes in respiration rate, ethylene production, oxidation and peroxidation process and activities of several enzymes related to phenolic oxidation in litchi fruit were determined after inoculating litchi fruit with Colletotrichum gloeosporioides. The results showed that after inoculation, both respiration rate and ethylene production of litchi fruit enhanced significantly, the rate of superoxide radical anion （O2） production and lipid peroxidation reactant-malondiaidehyde （MDA） increased, the activity of superoxide dismutase （SOD） decreased while polyphenoloxidase （PPO）, peroxidase（POD） and phenylalanine ammonia-lyase （PAL） promoted on litchi pericarp. All above indicated that the infection of Colletotrichum gloeosporioides could enhance respiration rate and ethylene production, accelerate the course of oxidation and peroxidation, and induce the activities of POD, PPO and PAL on litchi pericarp. So the infection of Colletotrichum gloeosporioides was one of the important reasons that quickened senescence, browning and decay of litchi fruit.