灵武长枣采后保鲜贮藏特性研究

以灵武长枣采后鲜果为试材,于不同贮藏条件下系统研究了其呼吸、乙烯释放、耗氧、失水及适宜贮温等特性,以期为灵武长枣贮藏保鲜措施制订提供依据。结果表明,八成熟灵武长枣在常温贮藏过程中,随贮藏时间延长,有呼吸高峰出现,乙烯释放呈双峰型;灵武长枣在果面完全着色时有呼吸升高和乙烯释放增加现象,灵武长枣可能为跃变型果实。灵武长枣采后耗氧迅速,极易失水,0℃恒温能显著延缓其后熟进程,保鲜期较常温延长21d。研究发现,控制环境低温,提高相对湿度和加强通风透气是灵武长枣贮藏保鲜的必要条件。     

乙烯释放和呼吸强度的变化与甜瓜果实贮藏期间成熟与衰老的关系

不同品种的甜瓜采收后和贮藏过程中乙烯释放和呼吸强度可分为三种类型:1.乙烯释放和呼吸均有跃变;2.呼吸下降而乙烯释放有跃变;3.乙烯释放和呼吸均平缓。第三种类型的贮藏质量较好。随着果实的成熟和贮藏时间的加长,果腔内 CO_2分压增加,O_2分压下降。     

哈密瓜成熟过程中ATP水平与呼吸跃变的关系

哈密瓜“黄旦子”果实在成熟过程中ATP的消长和乙烯释放及呼吸跃变期的变化曲线相似,但ATP高峰比呼吸高峰出现的早,和乙烯高峰的出现相同。外源乙烯有提高ATP水平的作用,也有促进内源乙烯产生和增加呼吸的作刚。ATP积累对温度的反应比呼吸对温度的反应敏感。     

百合花朵不同发育期乙烯释放量与膜脂过氧化作用的研究

以百合（lilium)“精萃”为材料,研究了百合花朵的不同发育期与乙烯释放量,呼吸强度变化情况,发现百合花朵的乙烯释放量和呼吸强度变化趋势基本一致,属于乙烯末期上升型花卉,并发现随着花朵的发育,不饱合脂肪酸指数（IuFA)逐渐下降,丙二醛（MDA）上升,细胞膜相对透性增加。     

保鲜剂对香石竹切花保鲜的生理效应

经由蔗糖、8-羟基喹啉和醋酸银组成的保鲜剂处理的香石竹切花瓶插寿命延长,吸水能力提高,乙烯生成受抑,乙烯释放高峰和呼吸跃变的出现推迟,吸水率与呼吸强度以及鲜重与花径之间都呈极显著相关。切花在乙烯释放高峰和呼吸跃变时,花瓣电导率迅速提高。保鲜剂抑制花瓣电导率的上升幅度。     

'嘎拉'苹果对不同浓度1-MCP处理的反应

以'嘎拉'('Kid's Orange'×'Delicious')苹果为试材,研究了0℃贮藏期间及贮藏30、60、90和120 d后转入室温7d货架期间1-MCP(1-甲基环丙烯)对果实呼吸速率、乙烯释放速率、品质和蛋白质变化的影响.结果表明,1-MCP处理显著抑制嘎拉苹果贮藏期间和贮后货架期间呼吸和乙烯释放速率,延缓果实硬度、可滴定酸含量的下降,对可溶性固形物含量无影响.对照果实在贮藏过程中,出现5条明显的特异性蛋白条带,1-MCP处理能抑制特异蛋白表达.300 nL·L-1浓度1-MCP处理与600 nL·L-11-MCP处理作用效果无显著差异.     

外源激素和病原侵染对采后葡萄呼吸速率及组织内源激素的影响

葡萄采后施用外源ABA可显著刺激其呼吸速率和乙烯释放率,ABA对呼吸的促进作用大于C2H4;当葡萄被交链孢和灰霉葡萄抱侵染后,呼吸和乙烯释放均加强。交链孢侵染的葡萄呼吸速率在孢子形成后2d达最大值,而灰霉葡萄孢侵染的葡萄呼吸速率在孢子形成时即达最大值。葡萄感病后,落粒现象加重,组织内源ABA和C2H4含量增加,IAA和GA3含量减少。     

阳桃果实在不同贮藏条件下乙烯和二氧化碳的释放

阳桃(Averrhoa carambola)是一种非呼吸跃变型水果。已有报道,其果实在20-25℃下贮藏,不出现呼吸跃变高峰和乙烯释放高峰,对外源乙烯处理也不敏感。本试验测定了两种不同成熟阶段(一为绿色未熟果,另一为25%变黄的成熟果)的阳桃果实在不同温度、不同气体组成和不同相对湿度下贮藏时,乙烯和CO₂的释放情况。试验结果如下。     

CEPA处理对苦瓜采后呼吸、乙烯释放及保护系统的影响

CEPA处理适期采收的食用苦瓜后,使其呼吸速率,乙烯释放速率明显增加,呼吸上升、瓜皮转黄期由采后第8天提前至第6天,且使贮期缩短4d。CEPA处理不同程度地抑制了苦瓜采后前期的各种保护酶活性,且使衰老后期的保护酶活性上升期提前。CEPA处理后前6d,AsA、GSH含量均呈上升趋势;6d后迅速下降,且下降速率大于CK。CEPA处理未改变苦瓜采后MDA含量总体下降的趋势。     

番茄子叶外植体芽的分化过程与乙烯释放的关系

本文对番茄子叶外植体培养过程乙烯的释放和芽的分化进行了研究,结果表明,番茄子叶外植体培养１ｈ后开始释放乙烯,第３小时乙烯释放达到最高峰,随后迅速下降,乙烯释放水平与番茄子叶外植体分化能力呈负相关,外植体芽的分化过程中,乙烯释放水平很低,但在芽形成以前略有增加,乙烯拮抗剂及其生物合成抑制剂促进子叶外植体芽的分化过程,伤害了可能是导致番茄子叶外植体乙烯释放的主要原因。     

缺硼对棉花 黄瓜和油菜乙烯释放的影响

本试验通过水培和土培试验的方法,研究了缺硼对棉花、油菜和黄瓜乙烯释放的影响。结果表明：缺硼条件下,棉花、黄瓜乙烯释放量显著增加,而油菜无论缺硼和正常硼条件下,乙烯释放量较低且没有明显差异,乙烯释放量的增加对棉花和黄瓜的生长发育有抑制作用;喷施乙烯合成抑制剂和乙烯生理效应抑制剂在一定程度上能减轻棉花和黄瓜的缺硼症状。黄瓜水培结果表明：在黄瓜缺硼症状出现前,乙烯释放量没有明显增加,随着缺硼时间的延长,缺硼症状的出现,乙烯释放量显著增加,因而乙烯释放量的增加不是缺硼导致黄瓜生理失调的直接反应。     

缺硼对棉花、黄瓜和油菜乙烯释放的影响

本试验通过水培和土培试验的方法,研究了缺硼对棉花、油菜和黄瓜乙烯释放的影响。结果表明：缺硼条件下,棉花、黄瓜乙烯释放量显著增加,而油菜无论缺硼和正常硼条件下,乙烯释放量较低且没有明显差异,乙烯释放量的增加对棉花和黄瓜的生长发育有抑制作用;喷施乙烯合成抑制剂和乙烯生理效应抑制剂在一定程度上能减轻棉花和黄瓜的缺硼症状。黄瓜水培结果表明：在黄瓜缺硼症状出现前,乙烯释放量没有明显增加,随着缺硼时间的延长,缺硼症状的出现,乙烯释放量显著增加,因而乙烯释放量的增加不是缺硼导致黄瓜生理失调的直接反应。     

Relationship Between Ethylene Release,Membrane Permeability and Activity of Polyphenol Oxidase Changes of Duck (Pears Pyrus bretschnideri Rehder) During Low Temperature Storage

Duck pear (Pyrus bretschneideri Rehder) tends to develop browning core after 55 to 60 days storage at low temperature (0℃). Following physiological changes of the duck pear during storage at different temperature were investigated: (1) As compared with 20℃, ethylene release is obviously decreased and its peak is retarded for 15 days at 0℃. Levels of internal ethylene are variant at different individuals harvested at same time. Concentrations of internal ethylene are in accord with ethylene release. The higher internal ethylene is, the easier the pear core becomes brown. (2) At 0℃, activity of polyphenol oxidase in the core increases with ethylene release enhancement. After ethylene peak passes, its activity is lower than before. (3) The electric conductivity of cores is higher at 0℃ than at 20℃. During post climacteric period, the electric conductivity increases irreversibly, then browning core occurs. From above results, it is concluded that interactions between two factors induce the browrang core of the duck pears at low temperature. One is chilling injury caused by low temperature, another is ethylene function. They stimulate the activity of polyphenol oxidase and enhance the membrane permeability.     

Approach to Physiological Functions of Ethrel in the Ripening of Cotton Boll

Both leaf and boll of cotton can absorb ethrel and the acceptor releases ethylene rapidly. Ethrel absorbed by leaves can release ethylene in bolls, whereas that absorbed by bolls cannot release ethylene in leaves. Bolls treated with ethrel has two peaks in ethylene releasing. The first peak appears about two days after treatment, and the second appears before the splitting of boll. The control has only one peak in ethylene releasing which appears eight days later than the second peak of the bolls treated with ethrel. This coincides with the fact that ethrel enables bolls to split seven to ten days earlier. The releasing of ethylene by cotton bolls is closely related to temperature, and is accelerated with increasing temperature no matter cotton bolls are treated with ethrel or not.     

Poly(ethylene glycol) quantitation by laser nephelometry

When poly(ethylene glycol) 3350 is estimated by the method of Skoog [(1979) Vox Sang. 37, 345-349], fine particles form. The particles are not attributable to residual protein but to a poly(ethylene glycol)/barium/iodine complex that can be quantitated by means of a laser nephelometer. The method is sensitive to at least 10 mg% poly(ethylene glycol) 3350 (4 micrograms in the cuvette) in 2500 mg% protein, and nephelometer response is approximately linear between 30 and 200 mg% of the polymer. The coefficient of variance is about 8%. Triton X-100, Pluronic F-68, Varonic 1000MS, and poly(ethylene glycol) of higher and lower molecular weight react well. Alkylated celluloses, dextrans, glycerol, glycine, and sodium dodecyl sulfate do not react significantly. Barium can be replaced with Mg, Ca, Ni, Fe, and other divalent cations in the reaction, but other than for Hg, light-scattering is most intense with Ba. The reaction goes to completion in about 5 min and is most intense when the barium is added before the iodine.     

Effects of Treatment with a Composite Preparation (2-Chloroethylphosphonic Acid and Methacide) or Butylated Hydroxyanisole on Ethylene Release in Apples

We studied the effect of a Russian composite preparation (2-chloroethylphosphonic acid and methacide) and butylated hydroxyanisole on ethylene release in whole fruit and peel disks of two apple cultivars, Antonovka obyknovennaya (Antonovka) and Simirenko's rennet (Simirenko). Treatment with the composite preparation was followed by an increase in ethylene release from both the whole apples and peel disks. The development of microbial infection (fruit rot) in the whole apples became less pronounced after the treatment. Treatment of whole apples with the antioxidant butylated hydroxyanisole (BHA) increased the intensity of ethylene release during the first subsequent days; thereafter, ethylene release decreased and was 10–15% lower than in the control on days 10–12. In model experiments, BHA decreased ethylene release from apple peel disks below control levels as early as on the first day after treatment. Antonovka apples gave quick responses to the treatment. In the late-ripening Simirenko apples, the response persisted for a longer period. Our results suggest that treatment with physiologically active preparations affects the ethylene release, ripening, and preservation of apples in storage.     

Effects of treatment with a composite preparation (2-chloroethylphosphonic acid and methacide) or butylated hydroxyanisole on ethylene release in apples

We studied the effect of a Russian composite preparation (2-chloroethylphosphonic acid and methacide) and butylated hydroxyanisole on ethylene release in whole fruit and peel disks of two apple cultivars, Antonovka obyknovennaya (Antonovka) and Simirenko's rennet (Simirenko). Treatment with the composite preparation was followed by an increase in ethylene release from whole apples and peel disks. The development of microbial infection (fruit rot) in whole apples became less pronounced after the treatment. Treatment of whole apples with the antioxidant butylated hydroxyanisole (BHA) increased the intensity of ethylene release during the first subsequent days; thereafter, ethylene release decreased and was 10-15% lower than in the control on days 10-12. In model experiments, BHA decreased ethylene release from apple peel disks below control levels as early as on day 1 after the treatment. Antonovka apples gave quick responses to the treatment. In the late-ripening Simirenko apples, the response persisted for a longer period. Our results suggest that treatment with physiologically active preparations affects ethylene release, ripening, and preservation of apples in storage.     

Ethylene and vegetative development

The past decade has witnessed a tremendous increase in our understanding of the role of ethylene in plant development. Genes encoding enzymes of the ethylene biosynthesis pathway have been isolated, allowing the manipulation of endogenous ethylene levels in intact plants. In parallel, a collection of ethylene mutants was obtained by using a simple response assay. This resulted in the identification of several genes involved in ethylene signal transduction. The data obtained using these new tools have allowed long-standing hypotheses to be tested, while gaining novel insight into the function of ethylene in development. Recent molecular evidence supported the existence of an intense hormonal cross-talk during plant growth. Numerous processes are controlled by ethylene in a close interaction with auxin, and often it was impossible to differentiate between auxin and ethylene effects. Molecular-genetic tools are now allowing the dissection of these interactions. Ethylene does not seem essential for many developmental processes. Nevertheless, it is of crucial importance for survival in most species as it occupies a key position in the developmental response mechanisms of plants under mechanical stress.     

Ethylene in seed dormancy and germination

The role of ethylene in the release of primary and secondary dormancy and the germination of non-dormant seeds under normal and stressed conditions is considered. In many species, exogenous ethylene, or ethephon – an ethylene-releasing compound - stimulates seed germination that may be inhibited because of embryo or coat dormancy, adverse environmental conditions or inhibitors (e.g. abscisic acid, jasmonate). Ethylene can either act alone, or synergistically or additively with other factors. The immediate precursor of ethylene biosynthesis, 1-aminocyclopropane-1-carboxylic acid (ACC), may also improve seed germination, but usually less effectively. Dormant or non-dormant inhibited seeds have a lower ethylene production ability, and ACC and ACC oxidase activity than non-dormant, uninhibited seeds. Aminoethoxyvinyl-glycine (AVG) partially or markedly inhibits ethylene biosynthesis in dormant or non-dormant seeds, but does not affect seed germination. Ethylene binding is required in seeds of many species for dormancy release or germination under optimal or adverse conditions. There are examples where induction of seed germination by some stimulators requires ethylene action. However, the mechanism of ethylene action is almost unknown.
The evidence presented here shows that ethylene performs a relatively vital role in dormancy release and seed germination of most plant species studied.