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1、摘要鸭梨(eyries bretschneideriRehd)，作为原产于国内、白梨晶系优良主栽品种之一，采后贮藏 申缀重要的一种生理病害是果心揭变。国内外对鸭梨这种病密发生的因素有多$说法，大多教注 黧了黪类秘覆凌PPO搀蠲下静生纯疫矗秘骥镕过氧话筝强，麓时氇注意鬟袋熬度、温度、麓C02、 乙烯、低Ca等指标的影响，值对于这些指标阐的联系，以及它们在鸭梨褐变发生中的互相作用， 述没有较为系统全面的论述。本研究拟定了鸭梨采后褐嶷的重要影响因素为采收成熟度和降温措施，在此基本上，选用两 静不嚣采牧或熟壤(9嚣上訇魏9莠下鼋采撼)豹鹎鬃，缝余不霜弱簿溢措施，霹急速海瀑(获 镥温直接降蓟0C)和缓慢
2、降漱(扶12 4C入庠，每5d减少2C，翔30d时闻降到O*C)，着重研 究了不同降温措施对不同采收成熟度鸭梨采后的抗逆性、酚擞物质、膜脂过氯化、膜脂脂肪酸、 c02溶解量及种予生理的影响，以及与鸭梨果实衰老及褐变的黄系。得到如一F结论：1。延迟采收提裹7果肉裁栗心的可潘性潮澎物、还原糖、Ve、GSH、可溶性蛋白、亚爨酸、 溉油酸含量和US氆，减少了袋肉和果心静穰交温凌，提商了鸦梨果实静抗冷往。毽采后栗实呼 吸、乙烯代谢妊盛，使得果实硬度、可滴定酸、可溶性固形物、还原糖、Vc、GSH、可溶性骚自 含量下降较快，SOD活性下降和LOX活性升高较快，H202、02一自由基积累，果实膜脂过氧 化严重
3、，丙二醛禽量升高，细胞膜透性增强，gl起PPO和PPO弼工酶活性增强，酚类物质减少， 娥终导致瞧采栗燹容荔福交，褥其中象心较豢巍变拖更为弱黧，簧鼓栗心较菜褒福变严羹。2急降温解决导致了对早采果实特别是聚心的低温伤害。与急降温相比，缓慢降温明显提瀚了早采果果肉和果心的可溶性爱白、亚油酸、皿麻酸含量芹“US值，减少了鸭梨果心的相变温 度，提高了鸭梨果实的抗性。缓慢降温减少f呼吸、乙烯代谢，提高了SOD活性，延缓了聚实 硬度、可薅定羧、霹溶淫国形锈、还蒙糖、霹漆犍蛋垂，殴疑贮藏最蘩Vc霹l GSH含量下洚，延 缓了果实LOX、PPO活性的升离，脯氨酸、H202、02一自滔蘸豹积累和膜鼹过氧纯，从褥缀
4、好克制了早采果实的褐变。其中缓慢降温对早采粱果心的影响照明显。3果皮部位占到整个鸭梨果实呼吸总量的90以上，C02在果实由内霉n外的组织中的溶解 蘸是递减的。C02在组织中的溶解量与温度、务器C02浓发及组织生理状态露荚，温度越低、C02 浓度越毫、组织麓衰老，疆绞肉溶鳃斡C02戆多，磊组织肉大鼙CCh簿低了缀织瘫永溶幢Ca含 懿。 ，4鸭梨种予属于采后呼吸高峰型。与果实同步浮现呼吸和乙烯高峰，邑烯在子房室内逐渐 积累。贮藏中鸭繁种子激素代谢旺盛，后期部分秘子萌发，种予呼吸、乙烯、子房室乙烯积累繁、 及电导率罄毒瓒势褰，秀裹覆覆与果实藕变静麓律赣毫冀，袭鹊耱子生瑾我谢与栗心或熟襄老没褥燮存在一
5、定联系。综上所述，不同降温措施和不同采收成熟度导致了鸭梨果实果肉和果心相变温度、内溶物、 抗逆性、呼吸z烯代谢、膜腊过氧化、种子生瑗、组织内部C02溶解量及水溶性ca含量的差别， 黢终导致对蒺黪搂痿不蘑，对PPO窝酸类携葳豹区域蛙分鞲酸垮限度的不弱，获磊影响了袋襄福 变的发生。鸭繁褐变与采牧藏熟发有很大关系，晚采果容易搦囊，提蓠采牧并结合缓降温对控制 鸭梨果实的褐黛有良好的效果。荚缝词： 鸭裂，褐变，降派措施，成熟艘，机理AbstractYali pear妒w bretschneideri Rehd)originated in 0111country is one of the major v
6、arieties of white pear lines，Browning hea娃has been one of the most severe postharvest physiological injury in storageAlthough there ate many reports about the reason why this kind of physiological injury happened，and yet most opinions only stressed the biochemical reactions of phenol catalyzed by PP
7、O， the lipid peroxidation of cell membrane and the physiological affecting factors such as mahdity, temperature，high C02，ethylene,tow Ca,and etcPresently,the relationship between these indexes and their interactions during browning of Yali pear have not been comprehensively elucidated yet。 The harve
8、st maturity and cooling methods were the main influence factors ofbrowning of Yapear fruitIn this paper，both early harvested Yati pear(picked in the first ten days of September)and the late harvested Yali pear(picked in the last ten days of September)were treated with slow cooling treatment (cooling
9、 from room temperature directly to 0)or rapid cooling treatment(storage at 12and cooling them to 0over 30 d by reducing temperature by 2every 5 mThe effects of the two cooling treatment on the pearS ability against stress，polyphenol content，membrane lipids peroxidation， membrane fatty acidscompositi
10、on，dissolved C02 ammmt and pear seed physiology were systematic-ally studied，So did the relationship between ripening and browningThe obtained main results are asfollows1Late harvest increased the content ofsoluble solid，reduced sugar,vitamin C，GSH，and soluble protein，linoleic acid，linolenic acid co
11、ntent and US value of flesh and core of Yali pearThe phase transition temperaturereduced。The pearS ability against stress wa暮improved。However,the lateharvested fruit had vigorous respiration and ethylene metabolism SO that the fruit hardness，titrated acid content，soluble solid content,reduced sugar
12、content,soluble protein content，vitamin C content and GSH content decreased very quicklyMoreover,the decrease of SOD activity and increase of LOX activity caused the accumulation ofhydrogen peroxide and superoxide radical，increase ofvlDA content mad severe oxidation of fruit membrane lipidsResultant
13、ly,the permeability of cell membrane Wasenhanced，which lead to the enzymatic activity increase of PPO and PPO isoenzyme and contentdecrease of phenolsAll these changes mentioned above finally made the late harvested fruits much easier to get browning。Moreovet the more severe browning was found in pe
14、arS core than in its flesh because ofthe more acute changes in its core2Rapid cooling induced cold injury沁early harvested pears and especially to their COles Compared with rapid cooling treatment，slow cooling treatment obviously increased the pear flesh and COreS soluble protein contenL Iinoleie aci
15、d content，Iinolenic acid content,and US value，reduced its phase transition temperature mad resultantly enhanced the Yafi pearS ability against stress Additionally,slow cooling slowered the metabolism of respiration and ethylene，enhanced the SOD activity,delayed the decrease offruit hardness，titrated acid content,soluble solid content，reduced sugarIIcontent，soluble protein content，vitamin C content and GSH content in late stage of storage强e increase ofenzymatic activity ofLOX，PPO and PPO isoenzyme+the accumulation ofproline，hydrogen peroxide and supero
