1-MCP对‘绿宝石’梨采后成熟衰老期间H2O2含量及其相关酶活性的影响

为探讨1-甲基环丙烯(1-MCP)对梨果实采后成熟衰老过程中过氧化氢(H2O2)代谢的作用,试验以‘绿宝石’梨为材料,用1.0 μL/L 1-MCP密封处理24 h,空气密封为对照,研究1-MCP对‘绿宝石’梨室温(25±2)℃贮藏过程中果实硬度、可溶性同形物含量(SSC)、呼吸速率、H2O2含量、抗氧化酶活性[超氧化...     

1-MCP对库尔勒香梨采后活性氧相关代谢的影响

[目的]研究1-甲基环丙烯(1-Methylcyclopropene,1-MCP)处理延缓库尔勒香梨采后衰老的机理,为香梨保鲜提供理论依据.[方法]以库尔勒香梨(Pyrus sinkiangensis Yu)为试材,研究1-甲基环丙烯处理对香梨果实贮藏期间活性氧代谢相关酶活性、超氧阴离子(O2·-)、丙二醛(MDA)、果皮色调角(h°)的影响.[结果]贮藏前期,1-MCP处理抑制了香梨果实超氧化物歧化酶(SOD)、过氧化物酶(POD)的活性,后期提高了POD的活性.整个贮藏期过氧化氢酶(CAT)活性低于对照;1-MCP处理果实丙二醛(MDA)含量低于对照果实;1-MCP处理在贮藏前期抑制超氧阴离子的产生,保持了较高的果实色调角.[结论]1-甲基环丙烯处理能够有效降低香梨活性氧产生速率,延缓果实衰老.     

Inhibitory Effects of 1-MCP and DPA on Superficial Scald of Dangshansuli Pear

Dangshansuli pear is one of crisp pears and has a non-climacteric respiratory pattern.Dangshansuli pear fruits were treated with 1 000 or 2 000 μL L-1 diphenylamine (DPA) for 1 min,or with 0.5 μL L-1 1-methylcyclopropene (1-MCP) for 12 h before cold storage at (2±0.5)℃ for up to 210 d.Incidences of superficial scald and related physiological indexes were investigated during storage.The results showed that superficial scald occurred in control fruit with a rate of over 90％ after 210 d at cold storage plus 10 d at room temperature.Treatments with 1 000 and 2000 μL L-1 DPA and 0.5 μL L-1 1-MCP inhibited the accumulation of αt-farnesene,conjugated trienes,total phenolic contents,and malondialdehyde (MDA) during storage.The treatments also decreased leakage of cell membrane and the activity of polyphenol oxidase (PPO) in the peel.These results indicate that I-MCP and DPA treatments inhibit and postpone the occurrence of superficial scald of Dangshansuli pears remarkably in cold storage and post-storage shelf life,respectively,while the mechanisms were different.The results above may provide a theoretical evidence for the agriculture production.     

低O2/高CO2气调结合1-MCP对‘玉露香’梨贮藏品质的影响

目的 明确低O₂/高CO₂对玉露香梨贮藏期保绿效果及品质维持的效果,为生产上延长‘玉露香’梨贮藏寿命提供理论依据与技术支撑。方法 分别将商业成熟的‘玉露香’梨进行1.0 μL·L^-1 1-甲基环丙烯（1-methylcyclopropene,1-MCP）处理,1% O₂、3% CO₂气调（controlled atmosphere,CA）贮藏以及1.0 μL·L^-1 1-MCP结合1% O₂、3% CO₂气调贮藏,以普通冷藏为对照,分别于贮藏210和240 d及货架7 d时,测定果皮颜色、叶绿素含量、果实硬度、可溶性固形物、可滴定酸、抗坏血酸等果实外观和内在品质指标,采用气相色谱法检测果实乙醇、乙醛含量以及乙烯释放量和呼吸强度,调查并计算果柄、果心褐变指数。结果 与普通冷藏相比,1-MCP、CA以及CA+1-MCP均可使‘玉露香’梨果实外观保持较好的绿色,有效减轻果面油腻化程度,在冷藏240 d及240+7 d货架时,CA+1-MCP对果皮绿色维持及油腻化控制效果更明显。1-MCP和CA均可抑制果实硬度、可溶性固形物和可滴定酸的下降,CA可抑制果心和果柄褐变,但CA降低了果实抗坏血酸含量,CA+1-MCP减缓了CA对果实抗坏血酸的破坏作用。CA+1-MCP对乙醇和乙醛的抑制作用在贮藏240 d时效果更明显,且20 mg·L^-1的乙醇含量在‘玉露香’梨耐受阈值以下。CA+1-MCP和1-MCP对果实乙烯释放量具有较好的抑制效果;240 d时,CA+1-MCP和CA对果实呼吸强度的抑制效果好于1-MCP。结论 ‘玉露香’梨较耐低O₂和高CO₂,CA+1-MCP对‘玉露香’梨的保鲜效果体现在210 d以后。因此,冷藏期在210 d以内,采用1.0 μL·L^-1的1-MCP处理;而冷藏期210 d以上,则需1% O₂、3% CO₂的低O₂/高CO₂的CA结合1.0 μL·L^-1的1-MCP处理,可保持果实较好的外观和内在品质。     

Ca2+参与硝普钠(SNP)对干旱胁迫下小麦幼苗叶片NO水平的调控

研究干旱胁迫下外源一氧化氮(NO)供体硝普钠(SNP)处理对小麦幼苗叶片NO水平的影响及其与Ca2+的关系.在15%PEG-6000胁迫下测定NO含量和NO合成酶活性,结果表明,干旱胁迫下小麦幼苗叶片一氧化氮合酶(NOS)活性显著增加,且钙依赖型cNoS(CaM的组成型NOS)快速调控NO产生,但是随着胁迫时间的延长,不依赖钙iNOS(CaM的诱导型NOS)的活性在NOS活性比例缓慢增加,而硝酸还原酶(NR)产生NO的能力只占总NR提取物活性的很小一部分;0.1 mmol/L SNP处理可显著提高干旱胁迫下小麦幼苗叶片NOS和NR活性,诱导NO水平提高,显著缓解膜脂过氧化;用质膜Ca2+通道抑制剂LaCl3与SNP共处理,显著减弱或抵消SNP促进NO合成作用.SNP显著提高干旱胁迫下小麦幼苗叶片NO合成酶活性和NO含量,有效缓解膜的氧化损伤,而Ca2+参与SNP对干旱胁迫下小麦幼苗叶片NO水平的调控.     

Optimal storage temperature and 1-MCP treatment combinations for different marketing times of Korla Xiang pears

Maintenance of green color is the primary indicator of quality in the market evaluation of Korla Xiang pears at present and can generally be achieved through early harvesting and decreasing the storage temperature, but the fruit quality was reduced by early harvesting, and the decreasing storage temperature increased the risk of chilling injury. The objectives of this study were to determine the optimal storage parameters for different storage times and to find ways to preserve the green skin color of pears. Specifically, we analyzed the effects of the ethylene inhibitor, 1-methylcyclopropene(1-MCP), combined with low temperature on quality and maintenance of the green color of Korla Xiang pears during storage. We found that 1-MCP and/or low temperature reduced the loss of green color at 20°C after being removed from cold storage. In addition, 1-MCP significantly inhibited the decline of titratable acid and ascorbic acid but had no significant effect on fruit firmness and total soluble solids. Low temperature with or without 1-MCP inhibited the release of ethylene, inhibited the decline in the stalk preservation index, inhibited the increase in decay rate and weight loss rate during storage, and inhibited the increase in the core browning index after 225 days of storage. Different storage temperatures had different effects on the quality of Korla Xiang pears. Despite inhibiting ethylene release, a storage temperature of –1.5°C increased the respiration rate. Storage at –1.5°C caused core browning early during storage due to chilling injury, whereas at 2°C core browning occurred late during storage due to senescence. In late storage, 1-MCP had no significant effect on the maintenance of Korla Xiang pear quality at 2°C. Based on these results, we determined the optimal combinations of low temperature and 1-MCP treatment to maintain pear quality while avoiding chilling injury. For different marketing times, the optimal conditions for storage until New Year's Day(a storage duration of 90 days) are 2°C or 1-MCP combined with 2°C. For storage until the Spring Festival(a storage duration of 150 days), the optimal conditions are 0°C or 1-MCP combined with 0°C, and for storage until May(a storage duration of 225 days), the best conditions are 1-MCP combined with –1.5°C.     

外源NO对采后芒果果实低温胁迫后H2O2代谢的影响

一氧化氮（NO）是植物体内重要的信号分子。为了探讨NO对采后芒果低温胁迫后果实过氧化氢（H2O2）及抗氧化酶的影响,分别采用0.08 mmol/L NO供体SNP溶液和30 μL/L NO气体处理采后青芒果果实,并于3℃低温贮藏12 d后,检测芒果果皮和果肉中H2O2含量和相关抗氧化酶的活性。结果表明,外源NO浸泡处理能显著降低低温胁迫后芒果果皮中H2O2水平,提高超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）的活性,其中NO对CAT活性的影响最大,可能是外源NO处理调控H2O2水平的关键作用点。NO供体SNP处理效果优于NO气体处理,主要作用部位为芒果果皮。     

Effects of 1-methylcyclopropene and modified atmosphere packaging on fruit quality and superficial scald in Yali pears during storage

The Yali pear(Pyrus bretschneideri Rehd.) is susceptible to superficial scald during prolonged cold storage and at shelf life. This study investigated the effects of 1-methylcyclopropene(1-MCP) and modified atmosphere packaging(MAP) on changes of fruit quality and superficial scald during cold storage and at shelf life in Yali pear. Compared with MAP, the combination of MAP and 1-MCP(MAP+1-MCP) treatment reduced the carbon dioxide and ethylene content inside the packaging bag. The 1-MCP, MAP, and MAP+1-MCP treatments reduced the superficial scald index, malondialdehyde content, O_2~-· production rate and relative conductivity and inhibited the accumulation of α-farnesene and conjugated trienes in the peel. 1-MCP and MAP+1-MCP treatments maintained a higher phenolic content and enhanced the catalase and superoxide dismutase activities in the fruit, while reduced activities of lipoxygenase and polyphenol oxidase in the peel preceding the onset of superficial scald. Comprehensive analysis indicated that the MAP+1-MCP treatment is the most effective method tested for improving the quality of Yali pears during cold storage and at shelf life.     

精确定量施肥技术对丰水梨品质和贮藏特性的影响

以丰水梨(Hosui)为试材,采用常规施肥+叶面喷水、常规施肥+叶面施肥和精确定量施肥3种施肥方法,在室温贮藏和1-MCP(1-甲基环丙烯)处理条件下,对其生理和品质的变化进行了研究。结果表明,室温贮藏条件下,3种不同施肥方式的丰水梨果实在贮藏过程中都出现呼吸高峰,呈现跃变型果实的特征,常规施肥的果实最先到达呼吸高峰,且峰值最高;果实可溶性固形物(TSS)含量表现出先升高后下降的趋势。精确施肥的果实在贮藏期间乙烯高峰出现时间晚,失水率低,能保持相对较高的硬度和TSS含量。室温条件下1-MCP处理12 h后,可以明显延缓果实硬度和果实失水率的下降,推迟乙烯高峰的出现,并阻碍TSS的增加速率,从而较好地保持果实在贮藏期间的品质和风味。     

1-MCP延长翠冠梨果实的货架期

以翠冠梨为试材,研究室温条件下1-甲基环丙烯(1-MCP)处理对延长果实货架期的效果。结果表明,1-MCP处理可以延缓果实硬度的下降,降低果实的呼吸速率,推迟乙烯峰的出现并降低峰值,维持果实较高的可溶性固形物(TSS)和可滴定酸(TA)含量,1-MCP处理还可以明显抑制梨黑皮病的发生,从而保持较高的好果率。因此,1-MCP处理能较好地保持果实在贮藏期间的品质和风味,使翠冠梨的货架期延长10 d左右。     

1-甲基环丙烯·壳聚糖对鲜切马铃薯活性氧代谢及保鲜效果的影响(英文)

[目的]研究1-MCP、壳聚糖处理对鲜切马铃薯贮藏期间活性氧代谢及保鲜效果的影响。[方法]设置1-MCP(2μl/L)、壳聚糖(2%)及1-MCP联合壳聚糖3个处理,以未加处理的鲜切马铃薯为对照,对鲜切马铃薯贮藏期间的相关指标进行测定。[结果]1-MCP处理能显著降低马铃薯呼吸作用,维持较高的SOD、POD活性,减少了O2-.和H2O2及MDA在体内的积累,延缓VC含量的下降,抑制PPO活性,表现出很好的贮藏效果;壳聚糖处理与1-MCP处理效果相反,但很好地抑制了鲜切马铃薯PPO活性;与对照相比,1-MCP联合壳聚糖虽有一定保鲜效果,但差异不明显。[结果]1-MCP处理鲜切马铃薯具有较好的保鲜效果。     

1-MCP和MA包装南水梨果实贮藏效果的影响

以南水梨果实为试材,分别研究了1-MCP处理对市售白袋和绿袋包装果实的冷藏期和货架期贮藏的果肉硬度、可溶性固形物(TSS)、可滴定酸含量和细胞膜相对透性以及果心褐变、果实腐烂和果柄保鲜的影响.结果表明:1-MCP处理在贮藏前期对南水梨的硬度和酸含量有一定的保持作用,抑制果肉细胞膜透性升高,抑制了TSS升高,有利于果柄保鲜,抑制了果心褐变,但对腐烂无明显作用.白袋的保鲜效果优于绿袋.     

几种贮藏方式对采后哈密瓜生理及贮藏品质的影响

[目的]研究几种贮藏方式对采后哈密瓜生理及贮藏品质的影响.[方法]以新疆哈密瓜西州密17号为试材,采用2～4、4～6、6～8、8～10℃4个贮藏温度下的杀菌剂、1-MCP、杀菌剂复合1-MCP技术对哈密瓜进行采后处理,定期测定哈密瓜采后贮藏期间的各项品质指标.研究几种贮藏方式对采后哈密瓜果实可溶性固形物、硬度、电导率、丙二醛（MDA）含量及POD、SOD与CAT酶活性等的影响.[结果]不同采后处理中,6～8℃条件下贮藏、采后杀菌剂复合1-MCP处理,CAT、POD、SOD酶活水平最高;8～10℃贮藏温度下、采后杀菌剂处理,MDA含量水平最高;4～6℃贮藏温度下、来后1-MCP处理,质膜透性最低;2～4℃贮藏温度下、采后1-MCP处理,果实硬度和哈密瓜中心TSS含量水平最高.[结论]6～8℃贮藏温度下对西州密17号进行采后杀菌剂复合1-MCP处理,减缓了哈密瓜可溶性固形物的消耗,抑制果实的软化,较好地保持哈密瓜的品质,有效延长哈密瓜的贮藏期.     

1-MCP 处理哈密瓜适宜窗口期的研究

用1-甲基环丙烯（1-MCP）处理采后不同时间间隔西州密25号哈密瓜,研究哈密瓜采后与1-MCP 处理之间的有效间隔,确定1-MCP 处理适宜的窗口期,为其在哈密瓜采后贮运中的应用提供理论依据。哈密瓜采后间隔6,12,24 h,分别用1-MCP 处理,贮藏在室温（25±2）℃条件下,测定果实品质指标。结果表明,1-MCP 处理保持哈密瓜贮藏期可溶性固形物和维生素 C 含量,延缓果实硬度的下降,抑制果皮叶绿素的分解,减少果实的失重和腐烂,抑制了丙二醛的累积。通过对试验结果的比较得出哈密瓜果实在采后12 h 内用1-MCP 处理能够较好的保持果实采后品质。     

酮病对荷斯坦奶牛抗氧化系统和一氧化氮含量的影响

[目的]研究新疆荷斯坦奶牛酮病血清中的部分生化指标的变化及其酮病致病机理的探讨。[方法]以新疆荷斯坦奶牛为试验动物,用酮粉法和改良的水杨醛检测法对其血清进行检测,应用硝酸还原酶法测定血清中一氧化氮(NO)含量和一氧化氮合酶(NOS)活性;应用DTNB显色法测定血清中GSH-Px活力,应用黄嘌呤氧化法测定血清中T-SOD活力,应用硫代巴比妥酸法测定血清中MDA含量。[结果]酮病奶牛血清中GSH-Px活力极显著降低(P0.01),T-SOD活力显著降低(P0.05),血清中MDA含量显著增高(P0.05);对照组奶牛血清中的NO含量和NOS活性均显著高于阳性组。[结论]酮病不但影响奶牛的抗氧化系统而且也会降低一氧化氮含量和一氧化氮酶的活性,对于揭示奶牛酮病的发生机理具有重要意义。     

Mixed-phase oxide catalyst based on Mn-mullite (Sm, Gd)Mn2O5 for NO oxidation in diesel exhaust

Oxidation of nitric oxide (NO) for subsequent efficient reduction in selective catalytic reduction or lean NO(x) trap devices continues to be a challenge in diesel engines because of the low efficiency and high cost of the currently used platinum (Pt)-based catalysts. We show that mixed-phase oxide materials based on Mn-mullite (Sm, Gd)Mn(2)O(5) are an efficient substitute for the current commercial Pt-based catalysts. Under laboratory-simulated diesel exhaust conditions, this mixed-phase oxide material was superior to Pt in terms of cost, thermal durability, and catalytic activity for NO oxidation. This oxide material is active at temperatures as low as 120°C with conversion maxima of ~45% higher than that achieved with Pt. Density functional theory and diffuse reflectance infrared Fourier transform spectroscopy provide insights into the NO-to-NO(2) reaction mechanism on catalytically active Mn-Mn sites via the intermediate nitrate species.     

1-MCP对毛笋采后活性氧代谢及品质的影响

[目的]研究1-MCP处理对毛笋贮藏期间活性氧代谢及木质化的影响。[方法]用25μl/L的1-MCP密闭处理毛笋24 h,以未加处理的为对照,然后在10℃下贮藏10 d,对毛笋贮藏期间的相关指标进行测定。[结果]1-MCP处理降低了贮藏期间毛笋的乙烯生成,延缓了组织硬度的增加,抑制了MDA、H2O2和O2-.的积累,同时保持了较高的SOD、CAT和APX活性。[结论]1-MCP通过调控活性氧代谢平衡延缓毛笋采后木质化。     

1-MCP二次处理对番木瓜采后生理生化及贮藏品质的影响

【目的】探讨1-MCP（1-甲基环丙烯）二次处理对番木瓜采后生理生化及贮藏品质的影响。【方法】以日升番木瓜果实为材料,研究在室温条件下,1mg／L 1-MCP一次处理和二次处理后对果实生理生化指标及贮藏寿命的影响。【结果】1-MCP处理推迟了番木瓜果实呼吸高峰的到来,抑制了叶绿素的分解,提高了蛋白质含量和SOD、POD活性,降低了O2^·-冶量和细胞膜透陛,但抑制果实TA和VC含量的上升,其中1-MCP二次处理的效果更突出。【结论】1-MCP二次处理更能延缓番木瓜果实的衰老。     

Impact of 1-MCP on postharvest quality of sweet cherry during cold storage

Sweet cherry (Prunus avium L.) is a kind of fruit with short postharvest life. Postharvest treatment of 1-methylcyclopropene (1-MCP: 1.0, 1.5 and 2.0 μL/L) was applied to cherry fruits, and its effects on postharvest fruit quality during 60-day-storage at cold temperature was investigated. Sweet cherry fruits were harvested at commercial fruit maturity and exposed to 1-MCP at 20±1°C for 24 h. Following 1-MCP treatments, the fruits were stored for 60 d at 90±5% RH and, 0±1°C, in three concentrations of 1.0, 1.5, and 2.0 μL/L 1-MCP, of which 1.5 μL/L 1-MCP had the most positive effect on fruit quality. Postharvest treatments of 1-MCP significantly reduced endogenous ethylene production, malondialdehyde (MDA) content, and polyphenol oxidase (PPO) activity in cherry fruits 60 d after cold storage when compared to untreated fruits. 1-MCP treatment was associated with lower respiration rate and relative electric conductivity (REC) and maintained cell membrane integrity. The results indicated that the treatment 1-MCP was effective in inhibition of the declining of POD activity and CATactivity. In conclusion, 1-MCP treatment could be a good candidate for maintaining postharvest quality of cherry, and 1-MCP could prolong the storage life of sweet cherry.     

半滑舌鳎组织器官中一氧化氮含量和一氧化氮合酶活性的测定

[目的]研究半滑舌鳎不同组织器官中一氧化氮（NO）含量和不同类型一氧化氮合酶（NOS）活性。[方法]采用Griess试剂法测定NO含量,采用化学比浊法测定NOS的活性。[结果]诱导型一氧化氮合酶（iNOS）在肌肉组织中活性最高,为28.774±4.10 U/mgprot,依次为肠、脑、肝脏、头肾、鳃、中肾、脾脏、心脏。肠和脑之间以及肝脏和头肾之间iNOS的活性不存在显著性差异,而其他组织器官之间iNOS的活性都存在显著性差异。结构型一氧化氮合酶（cNOS）在肠组织中活性最高,为55.979±5.048 U/mgprot。所测组织器官中cNOS活性都存在显著性差异。NO含量在脾脏中最高,为38.540±4.535μmol/L。脾脏、头肾、肝脏之间,以及脑、心脏、中肾之间NO含量不存在显著性差异,而其他组织器官之间NO含量都存在显著性差异。[结论]不同组织器官中NO含量和NOS活性不同,这可能与组织器官功能有着密切联系。