【作者】 张海燕；

【导师】 饶景萍；

【作者基本信息】 西北农林科技大学 ， 果树学， 2008， 硕士

【摘要】 为了给油桃抗冷害技术的研究提供参考,本试验以油桃品种‘秦光2号’为试材,清水浸果为对照,研究冷藏条件下(0±0.5℃)外源腐胺(Put)在提高油桃果实耐冷性、降低贮藏冷害及延缓贮藏品质变化等方面的作用,同时也研究了处理后油桃果实内源多胺含量、呼吸速率和乙烯释放量、活性氧清除酶和脂氧合酶活性、胞壁物质相关酶活性的变化。结果表明:1.在1 mmol/L、3 mmol/L、10 mmol/L、15 mmol/L不同的处理浓度中,以浓度为10 mmol/L Put处理的效果最明显。2.在冷藏条件下,Put诱导了油桃的耐冷性,10 mmol/L Put处理的油桃果实冷害比对照延迟10 d发生,冷害发生率和冷害指数显著下降,冷藏50 d时,油桃果实的冷害发生率和冷害指数比对照分别降低了30.0%和18.3%;内源Put含量在贮藏期间大量积累并于45 d时出现高峰,精胺(Spm)、亚精胺(Spd)含量均持续增加,外源Put提高了油桃果实内源多胺含量,延缓了油桃果实冷害发生。3. Put有效地降低了油桃果实的失重率,使TSS含量维持在一个较高水平,减缓了贮藏期间果实的硬度、Vc含量的下降速度,但Put对油桃中TA含量和叶绿素含量影响不显著,对保持油桃果实的风味和品质有利。4. Put降低了油桃果实的呼吸速率,有效抑制了乙烯的生成和释放,呼吸高峰和乙烯释放高峰的出现均推迟5 d。5. Put能有效抑制油桃果实细胞壁结构物质相关酶类PG、PE活性的上升,降低果实硬度下降的速度;并且Put还提高了三种抗氧化酶(SOD、CAT、POD)的活性,降低了LOX酶活性,抑制了相对膜透性和MDA含量的上升,提高内源自由基的清除水平,从而减轻了油桃的膜脂过氧化,保持了油桃果实细胞膜结构和功能的完整性,减轻冷害的发生。综合各项指标分析认为,外源Put对采后油桃果实贮藏冷害的调控作用显著。可有效降低油桃果实的冷害发生率和冷害指数,保持油桃果实较好的风味和品质,抑制油桃果实的呼吸速率和乙烯释放量,对延缓油桃果实成熟与衰老的进程有一定的效果。因而,可以认为Put在果实采后贮藏保鲜中具有较好的开发应用前景。更多还原

【Abstract】 In order to study the effects of exogenous putrescine (Put) treatment on chilling injury of nectarine fruits during cold storage (0±0.5℃) . With the nectarine variety‘Qinguang 2’as tested material, non-treatment as ck. The effects on improving the cold tolerance、decreasing the chilling injury rate and keeping fruits quality were studied in this paper. Concurrently the content of endogenous polyamines, respiration rate, ethylene production, activated oxygen scavenging enzymes and LOX activities and the activities of amylase correlated cell wall substance (cellulose pectin). The result showed as follows:1. Compared with the effect of Put treatment of different concentrations (1 mmol/L、3 mmol/L、10 mmol/L、15 mmol/L), the effect of 10 mmol/L treatment was the best.2. Under cold storage, Put treatment induced cold tolerance in nectarine fruits, the chilling injury was delayed for 10 days by exogenous Put (10mmoL/L) treatment, the chilling injury rate and chilling injury index were different from ck. Compared with the ck, the chilling injury rate and chilling injury index of Put decreased 30.0%and 18.3% after 50 days storage. The contents of endogenous Put level increased during cold storage and reached a peak value after 45 days, spermidine (Spd) and spermine (Spm) level increased continuously, Put treatment raised the endogenous polyamines content of nectarine fruits. Delayed the chilling injury of nectarine fruits effectively.3. Put decreased the weight loss rate, made the content of total soluble solid (TSS) at a high level. At the same time the degradation rate of the flesh firmness,vitamin c (Vc) of nectarine fruits were reduced obviously. However, it showed no remarkable effect on the contents of titratable acidity (TA) and chlorophyll. So it was help to the fruits’favor and qualities.4. Put decreased the respiration rate, restrained the ethylene create and production of nectarines. Compared with ck, the peak of respiration rate and ethylene production delayed for 5 days.5. Put restrained the degradation of polygalacturonase (PG) and pectinmethylesterase (PE) activities, which put off the fruit softening process and maintained their flesh firmness of nectarine fruits. Meantime, Put significantly raised the activities of membrane superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) and inhibited the lipoxygenase (LOX) activity; the malondialdehyde (MDA) content and the increase in the relative membrane permeability were slowed down. so that Put enhanced the levels of free radical cleaning ,alleviated lipid peroxidation and maintained better cell membrane integrity, and reduced the occurrence of chilling injury.In comprehensive consideration, the Put treatment has remarkable effect on nectarine chilling injury during cold storage, which could delay the chilling injury rate and chilling injury index, keep quality and flavor of nectarine fruits preferably, suppressed the respiration rate and ethylene production, postpone the caducity of nectarine fruits in a certain. So that Put has a better prospect in the storage of fruit and vegetable.更多还原