苹果α-法尼烯和共轭三烯含量变化与贮藏温度的关系

 以‘红星’苹果为试材，研究α-法尼烯和共轭三烯的合成和转化部位，试验表明，α-法尼烯在果实表皮角质层中大量合成，分别向外蜡质层和向内皮下细胞和果肉薄壁细胞双向转移，在果实表皮蜡质层或角质层中与氧接触，氧化生成共轭三烯和其它氧化产物；虎皮病发生、α-法尼烯与共轭三烯的含量都与贮藏温度呈显著的负相关。     

苹果果皮细胞膜结构变化与虎皮病的关系

国光苹果在贮藏过程中,果皮内α—法尼烯不断积累,60天左右达最大值,后随共轭三烯的迅速增加而下降。与此同时,果皮中丙二醛积累,组织相对电导率增加。抗氧化剂二苯胺能显著降低果皮中丙二醛积累,阻止相对电导率的上升,减少发病率。对膜结构变化与虎皮病的关系进行了讨论。     

Postharvest heat treatment as a possible means of reducing superficial scald of apples

A pre-storage heat treatment of 38°C for four days applied to apples (Malus domestica cv. ‘Granny Smith’) before standard storage in air at 0°C was found to inhibit the development of superficial scald. Apples stored for three months after heat treatment had superficial scald levels similar to those of apples dipped in diphenylamine (DPA), while all control apples had scald. This inhibitory effect was no longer apparent after five months of storage. The heat treatment inhibited the accumulation of α-farnesene and conjugated trienes in apple cuticle while DPA inhibited only a-farnesene oxidation. Heat treated apples also had lower polyphenoloxidase activity in the peel than untreated apples. This treatment may be a substitute for chemical treatments for short-term storage of scald- susceptible apple varieties.     

苹果和梨AFS基因启动子的克隆、序列比对及功能分析

苹果（Malus × domestica L.）和梨（Pyrus communis L.）果实在低温储存过程中虎皮病的发生与果皮中受乙烯诱导的α–法尼烯合酶基因（AFS）的表达及α–法尼烯的积累密切相关。采用TAIL-PCR技术分别从‘富士’苹果和‘丰产’梨中克隆到了约2 kb的α–法尼烯合酶基因（AFS）启动子序列,并提交至GenBank中（登录号分别为KM676083和KM676082）。序列比对发现两启动子同源性仅为48.31%,远低于其下游编码区97%的相似度。顺式作用元件在线预测分析发现二者同时存在乙烯、脱落酸、茉莉酸、水杨酸等激素响应元件,低温、厌氧、病原菌等胁迫响应元件,以及3个节律性表达元件和2个诱导子响应元件。对‘丰产’梨中AFS基因表达模式的分析也证实了部分预测的诱导因素对其表达有调控作用。将‘丰产’梨AFS基因启动子序列进行系列删除,与GUS报告基因构建融合表达载体转化烟草,利用GUS染色方法分析了不同长度启动子的转录活性差异,发现缩短至153 bp的启动子片段仍具有较强的转录活性,且长度在276 bp至573 bp的启动子片段其驱动下游基因转录的活性较其他片段更强。通过后续对各作用元件尤其是乙烯响应元件的研究将有助于进一步从分子水平认识虎皮病的发生机制。     

Changes in Ripening Behaviors of 1-MCP-Treated ‘d’Anjou' Pears After Storage

Abstract

1-Methylcyclopropene (1-MCP), an ethylene action inhibitor, was applied to ‘d’Anjou' pears (Pyrus communis L.) at 20°C between 2 and 5 days after harvest. Scald of ‘d’Anjou' pears was completely controlled by 1-MCP at a concentration between 0.05 and 0.3 µl l1 after a prolonged cold storage plus 7 days of exposure to an environment with or without 500 µl l1 ethylene at a temperature of 20°C or 25°C. 1-MCP inhibited the biosyntheses of α-farnesene and its oxidative products (conjugated trienes) and thus controlled scald. However, fruit treated with the above concentrations of 1-MCP did not ripen normally in an environment with or without ethylene. Ethylene production and fruit softening of 1-MCP-treated ‘d’Anjou' pears were inhibited during 7 and 15 days at 20°C. ‘d’Anjou' fruit treated with 0.01 and 0.02 µl l¹ 1-MCP ripened normally on day 7 at 20°C after 3 months of cold storage at ? 1°C, and ripened fruit did not develop any incidence of scald. Untreated fruit developed substantial scald. After 4 months of storage or longer, both untreated fruit and fruit treated with 0.01 and 0.02 µl l 1 1-MCP developed an unacceptable incidence of scald upon ripening. Thus, use of other scald control methods may be necessary in addition to treatment with a low dosage of 1-MCP to insure both normal ripening and scald control for d'Anjou pear fruit from the Mid-Columbia district.     

早熟砂梨‘翠冠’hmgr基因家族两成员的表达与货架期黑皮病关系的研究

 以砂梨黑皮病易感品种‘翠冠’果实为材料,克隆获得了调控α-法尼烯合成的关键限速酶3-羟基-3-甲基戊二酸单酰辅酶A还原酶（HMGR）基因家族中的两个成员Pphmgr1和Pphmgr2。Pphmgr1开放阅读框为1 827 bp,编码由609个氨基酸残基组成的蛋白;Pphmgr2开放阅读框为1 707 bp,编码由569个氨基酸残基组成的蛋白。序列比对结果显示：‘翠冠’PpHMGR1和PpHMGR2与苹果果实的MdHMGR1和MdHMGR2蛋白的同源性分别达到90%和98%。在采后货架期28~32 ℃条件下,乙烯受体抑制剂1-MCP 可明显抑制果实呼吸率,减缓乙烯释放,显著降低果皮中α-法尼烯及其氧化产物共轭三烯的含量,减少黑皮病发病率并减轻发病程度。半定量RT-PCR结果显示1-MCP处理后果皮中Pphmgr2的表达受到显著抑制,但是Pphmgr1的表达几乎不受影响。     

Heat treatment and harvest date interact in their effect on superficial scald of ‘Granny Smith’ apple

A study was made of the effect of hot water dips (HWD) at temperatures of 42, 44, 46 and 48 °C (HWD 42 °C, HWD 44 °C, HWD 46 °C and HWD 48 °C, respectively) for 3 min on development of superficial scald and the concentration of α-farnesene and conjugated trienols (CT), CT₂₅₉, CT₂₆₉, CT₂₈₁, as well as OD₂₀₀ on Granny Smith apple fruits harvested on three dates and stored 125 days in air at 2 °C. HWD 48 °C efficiently decreased surface scald in the second and third harvest. α-Farnesene and CT were measured spectrophotometrically and by HPLC. No clear relationship of OD₂₀₀ and scald development was observed. Correlation of scald index and OD₂₀₀ at the end of storage was negative for the second harvest date. There was no significant correlation between the scald index and CT₂₅₉. Scald index was positively correlated with CT₂₆₉ after 80 days for the second and third harvest and at the end of storage for the second harvest. CT₂₈₁ was spectrophotometrically detectable only at the end of the storage, for the third harvest date, in control, HWD 42 °C, and HWD 44 °C. HWD 42 °C had significantly higher CT₂₈₁ compared to HWD 44 °C and control. HPLC analysis of control samples revealed presence of CT₂₈₁ in all three harvest dates, and presence of at least two components, as was the case of CT₂₅₉ and CT₂₆₉. The ratio of these two components was different for all three CT species. Fruit maturity was an important factor determining the response of fruit to heat and occurrence of superficial scald. The results indicate that a successful treatment using HWD to control superficial scald may be obtained after further research and that there are still some questions on the role of different CT's in scald biochemistry that should be addressed in future research.     

苹果低氧气调新组合及其防治虎皮病的效果

以玫瑰红苹果为试材研究０℃和１０℃温度下２％Ｏ2与３％、７．５％、１２％ＣＯ２不同气调组合处理的效果。选出在０℃和１０℃下气调新组合２％Ｏ２＋７．５％ＣＯ２,其特点是Ｏ２浓度在低氧气调范围内,ＣＯ２浓度明显高于国外低氧气调。低氧气调新组合处理果实 １２１ｄ,果肉硬度和果皮叶绿素含量高于对照（Ｏ℃＋空气）,果皮α－法尼烯和共轭三烯含量显著低于对照。其中 １０℃＋ ２％ Ｏ２＋７．５％ＣＯ２处理果实再在２０℃空气中放７ ｄ或在５－７℃空气中放 １２２ ｄ后,未发现虎皮病果,０℃＋２％Ｏ２＋７．５％ＣＯ２处理果实则在５－７℃空气中再放３０ ｄ后也未发生虎皮病,说明低氧气调新组合处理可防止果实在贮后一段时间内发生虎皮病,应注意低氧气调新组合处理败后效应的利用。     

前期低氧处理对梨虎皮病的防控及乙烯释放的影响

以'鸭梨'为试材,空气处理为对照,分析比较前期超低氧胁迫(0.8％02+0.5％C02处理15 d,转入5.0％02+0.5％C02长期贮藏)、静态低氧气调(降温后直接转入5.0％02+0.5％C02)和"两阶段"缓慢降氧气调(10.0％02+0.5％C02处理15d,转入5.0％02+0.5％C02长期贮藏)对'鸭梨...     

BX—1型保鲜纸防治苹果虎皮病和梨黑皮病的效应

应用BX-1型保鲜纸可有效地防治苹果和梨贮藏期间的表皮褐变。苹果和梨的表皮褐变与果皮中α—法尼烯含量没有直接关系,与α—法尼烯的氧化产物共轭三烯含量直接相关。BX-1型保鲜纸防治苹果和梨表皮褐变的作用机理在于:1.抑制果皮中α—法尼烯的氧化作用;2.吸收果皮组织中共轭三烯,降低共轭三烯在果皮中的含量。     

Studies of the Physiologically-Active Volatile Organic Compounds Produced By Fruits: I. The Concentrations of Volatile Organic Compounds Occurring in Gas Stores Containing Apples

When apples begin to ripen after gathering, volatile products are given off. Some of these account for the smell of the fruit; another is the gas ethylene. These volatile products affect the rate at which the apples ripen, and are probably also responsible for such diseases of storage as superficial scald and spotting of the lenticels. The volatile products tend to collect in the atmosphere of the store and hence also m the fruit, particularly with tight packing or when the ventilation is restricted, as in gas storage. It is necessary to use oiled paper wraps in gas-storage, to prevent scald, but this is a laborious and somewhat costly procedure. It is hoped to reduce the amount of the volatiles in the atmosphere of the store, and thus to control scald, by employing a filter containing some material to absorb the volatiles. The filter would have the atmosphere of the store circulated through it, and could be fitted either inside or outside the store.

This paper describes an investigation, the first of its kind, of the amounts of the volatile products occurring in the atmosphere of gas-stores under present methods of operation. The main feature is the suprisingly high concentration of ethylene found in the stores. The amount present would, in ordinary air, be expected to cause stimulation and acceleration of ripening.

This raises the question whether, if ethylene could be removed, further benefits in delay of ripening could be obtained.     

Effect of insulin on early myocardial oxidative stress in severely burnt rats

AIM：To investigate the effect of insulin on early myocardial oxidative stress in severely burnt rats. METHODS：Twenty-four Sprague-Dawley rats were randomly divided into three groups (8 rats in each group): control group (sham scald group), scald injury group and scald injury + insulin group. The rats in the latter two groups were subject to third-degree burn with 30% total burn surface area (TBSA) on the back, and then received intraperitoneal injection of normal saline (40 mL/kg) immediately. The rats in scald injury + insulin group were subcutaneously injected with insulin (1 U/kg), while those in scald injury group received subcutaneous injection of the same volume of normal saline. All rats were sacrificed 24 h after scald, and blood samples from abdominal aorta and myocardial tissues were taken. Blood glucose (BG) content, blood lactate dehydrogenase (LDH) and creatine kinase (CK) activity, and myocardial oxidative and antioxidative indexes, including malondialdehyde (MDA), xanthine oxidase (XO), myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT) and glutathion peroxidase (GPx), were detected by spectrophotometry. RESULTS：(1) Compared with control group, BG levels in scald injury group and scald injury + insulin group were significantly elevated (P<0.05). But BG in scald injury + insulin group was significantly lower than that in scald injury group (P<0.05). (2) Compared with control group, the activity of LDH and CK in scald injury group was significantly increased (P<0.05), while that in scald injury + insulin group was significantly lower than that in scald injury group (P<0.05). (3) Compared with control group, the MDA content and the XOD and MPO activity in scald injury group were significantly increased (P<0.05), while the activity of SO, CAT and GPx was significantly decreased (P<0.05). Compared with scald injury group, the MDA content and the XO and MPO activity in scald injury + insulin group were significantly reduced (P<0.05), while the activity of SOD, CAT and GPx was significantly elevated (P<0.05). CONCLUSION：Insulin intervention attenuates early myocardial oxidative stress in burnt rats and decreases the rise in myocardial enzyme activity, thus exerting a cardioprotective effect.     

Multiformulation dips for controlling storage disorders of apples and pears. II. Assessing scald inhibitors

Superficial scald (scald) was adequately controlled by diphenylamine (DPA), butylated hydroxytoluene (BHT and Topanol), and Ethoxyquin and partly controlled by Topanol O (a BHT emulsion formulated for calcium chloride compatibility). Mixing calcium chloride (calcium) with these scald-inhibitors tended to improve the level of scald control, although this effect was not always significant, and Benlate reduced the effectiveness of Ethoxyquin. The phytotoxic effect of individual dip components caused appreciable wastage from lenticel spotting. Lowest lenticel spotting occurred with Ethoxyquin and DPA miscible oil (MO), while BHT miscible oil formulations Topanol and Topanol O caused excessive spotting. Calcium was also highly co-inductive to lenticel spotting, and this effect was compounded by the inclusion of scald inhibitors with calcium. In using mixed ingredient (multiformulation) dips, DPA as a miscible oil or powder gave effective scald control without greatly increasing lenticel spot when calcium was added. However, this effect was more apparent on ‘Granny Smith’ and since calcium did not improve fruit firmness on ‘Delicious’, its inclusion in post-harvest dips for this cultivar is not warranted.     

苹果双变气调生理基础的探讨

双变气调以低O_2高CO_2处理克服或抑制贮藏初期较高温度的不利影响.试验结果表明,在10—15℃高温度下低O_2高CO_2处理果实的呼吸强度和果内乙烯浓度较低;在温度和CO_2浓度协同降低后,处理果实的呼吸强度和果内乙烯浓度持续较低,其果皮α-法尼烯和共轭三烯含量明显低于冷藏对照.     

Control of superficial scald in ‘Granny Smith’ apples by ultra-low and stress levels of oxygen as an alternative to diphenylamine

Summary

‘Granny Smith’ apples were harvested at weekly intervals, commencing approximately 155 d after full bloom (DFFB), over two successive seasons. Subsamples of the fruit were stored for periods of five and six months, without the application of diphenylamine, under regular atmosphere (RA) (1990/91 season only), and ultra-low oxygen (ULO) controlled atmosphere (CA) conditions. Further samples were subjected to initial low oxygen stress (ILOS) conditions before ULO CA storage. During the 1989/90 season, scald development after five months’ storage was low for fruit which had been picked in the pre- and post-maturity phases, but high on fruit picked at optimum maturity (170 DFFB). Although storage regime had little effect on scald development after five months’ storage, the ILOS + ULO CA treatment resulted in lower levels of scald on the post-mature fruit after six months of storage than was the case under ULO CA storage alone. There was more scald in the 1990/91 season than in the previous season. Under RA storage conditions, scald levels were high after both five and six months of storage, and decreased only slightly the later the apples were picked. Relative to RA, storage under ULC CA conditions led to markedly lower scald levels on the post-mature fruit, but did not greatly reduce scald on the pre-mature and mature fruit. Storage under the ILOS + ULO CA regime, however, conferred low levels of superficial scald on pre-mature, mature and post-mature fruit after both five and six months of storage. These results suggest that although superficial scald on ‘Granny Smith’ apples can be inhibited by a combination of ILOS and ULO CA storage, the development of scald is also affected by factors other than maturity and storage period.     

Preharvest applications of ethephon reduce superficial scald of ‘Fuji’ and ‘Granny Smith’ apples in storage

In 1989 and 1990, preharvest applications of 2-chloroethyl phosphonic acid (ethephon) at dosages from 50–400 mg 1’1 were applied to ‘Fuji’ and ‘Granny Smith’ apples. In 1989, the greatest reduction in scald after storage on both ‘Fuji’ and ‘Granny Smith’, relative to the untreated control resulted from applying 400 mg 1^?1 ethephon five weeks before harvest and was 45% and 55% of controls, respectively. On ‘Granny Smith’ 400 mg 1^? was also effective when applied three weeks before harvest. In 1990, preharvest applications of ethephon at either 200 or 400 mg 1^?1 reduced scald in both cultivars relative to the controls. Ethephon applied six weeks before harvest had no dosage effect on scald reduction after storage. There was no consistent effect on fruit maturity at harvest from any treatment in either year, and no effect on quality of fruit out of storage.     

虎皮病的防治研究概况

虎皮病的防治主要包括化学和非化学防治。化学防治的方法很多,目前最有效的是使用二苯胺,但是人类出于对自身健康的考虑,许多消费者已开始不愿接受化学处理的果实,非化学防治成为人们研究的热点。非化学防治主要包括气调贮藏、采后热处理和虎皮病预测。     

Studies of the Physiologically-Active Volatile Organic Compounds Produced by Fruits : II. The Rate of Production of Carbon Dioxide and of Volatile Organic Compounds by King Edward VII Apples in Gas Storage,and the Effect of Removal of the Volatiles From the Atmosphere of the Store on the Incidence of Superficial Scald

The present method of controlling superficial scald of apples in gas storage by wrapping them in paper containing oil is usually very effective but is costly. This is mainly because it requires so much labour. It also takes time and delays the closing of the store. Can simpler, equally effective methods be found ? It was expected that removal of part of the volatile vapours given off by the apples, by circulating the storage atmosphere through a gas-mask type of filter, would reduce scald. This expectation was based on the theory that scald is caused by the accumulation of one or more of these volatiles in the storage atmosphere. Suitable filters were developed and experiments in which the storage atmosphere was analysed showed that these filters did remove a very large part of the apple volatiles. Nevertheless, it was found that the amount of scald occurring on unwrapped King Edward VII apples in gas storage was almost the same in a store with filters as in one without.

The well-known effect of gas storage in lowering the rate at which apples lose CO₂ is shown in the present paper by means of diagrams. It is this condition which is responsible for the extension of storage life of apples in gas mixtures.     

Chlorophyll fluorescence as affected by some superficial defects in stored apples

Summary

Chlorophyll fluorescence, skin coloration and surface contour were measured for apple (Malus domestica Borkh.) fruit with and without common storage and handling surface defects. Defects included C0₂ injury in ‘Empire’, bitter pit in ‘Jonagold’, superficial scald in ‘Cortland’, ‘Law Rome’, ‘Gala’ and ‘Red Delicious’ and bruising in ‘Cortland’. Measurements were made along a transect established on the fruit surface. The fluorescence parameters, minimal fluorescence (Fo), maximal fluorescence (Fm) and photochemical efficiency (Fv/Fm, where Fv = Fm - Fo) were relatively similar around the circumference of undamaged control fruit. Skin colour was not found to influence chlorophyll fluorescence. With the exception of bruises, there were marked changes in fluorescence in the areas where surface disorders or damage had developed. C02 injury and bitter pit reduced Fv/Fm, whereas superficial scald did not. However, scald symptoms were accompanied by a reduction in Fo and Fm. The reduction in Fo and Fm became more marked as scald symptoms intensified during post-storage holding at 22°C. Chlorophyll fluorescence may have some potential for sorting fruit having superficial defects.     

低温对苹果贮藏过程中H_2O_2水平的影响

在低温贮藏条件下,苹果虎皮病从11一12月间开始发生并迅速加重.在此之前,果皮中H_2O_2水平逐渐上升,11—12月达最大值.H_2O_2水平的变化与细胞中保护系统和木质素合成有关.与晚采果相比,早采果中SOD和CAT活性均高,低温下CAT活性较SOD下降为快,早采果尤为显著,因此果皮中H_2O_2水平也高.抗氧化剂二苯胺对SOD和CAT无影响,但显著抑制木质素合成,降低H_2O_2水平,减少发病率.