OsWR2-RNAi对水稻角质层生物合成和耐旱性的影响

植物的角质层在干旱胁迫下对降低植物的非气孔性失水起重要作用。对水稻蜡质相关转录因子基因OsWR2过表达研究发现,OsWR2对水稻表皮蜡质和角质的含量和组分构成以及非气孔性失水均有影响,推测OsWR2是植物角质层代谢途径中重要的调控基因。本研究通过构建OsWR2-RNAi载体并转入水稻获得抑制OsWR2表达的突变转基因植株,发现OsWR2-RNAi水稻叶片角质层组成和含量明显变化,其蜡质组分中醛类、醇类和烷烃类的减少导致表皮蜡质晶体的积累和表皮蜡质总量减少14.8%,角质单体中C16:0ω-OH、C18:1ω-OH脂肪酸和di-OH脂肪酸等角质组分含量的显著降低导致OsWR2-RNAi水稻叶片中角质单体总量减少36.2%。幼苗干旱处理前后,OsWR2-RNAi植株自由脯氨酸含量与野生型相比变化不大,但其表皮通透性、水分散失率和MAD含量显著增加,幼苗耐旱性降低。本研究结果进一步证实OSWR2对水稻蜡质和角质生物合成及对非气孔性失水的调控作用,有望为水稻耐旱性状的改良提供重要基因资源。     

套袋与采后涂膜对红富士苹果果实贮藏效果的影响

以长富2号红富士苹果为试材,在实验室条件下观察了套袋与采后涂膜处理对红富士苹果果实贮藏效果的影响。试验结果表明,苹果果实套袋可使果实表面蜡质减少,角质层变薄且疏松,呼吸强度增大,贮藏期更容易失水,从而导致耐贮性能下降。而将套袋果实进行单果涂膜处理,可抑制其在贮藏过程中的呼吸强度与失水程度,从而延缓红富士苹果果实衰老进程及改善贮藏性能。     

SA、MeJA和ACC处理对甘蓝型油菜叶角质层蜡质组分、结构及渗透性的影响

角质层蜡质与植物适应逆境胁迫有关。本研究以甘蓝型油菜中双11为试材,在五叶期分别对其进行200 μmol L^–1水杨酸(SA)溶液、1-氨基环丙烷-1-羧酸(ACC)溶液以及100 μmol L^–1茉莉酸甲酯(MeJA)溶液浇灌处理,分析油菜叶角质层蜡质组分含量、结构以及角质层渗透性的变化。结果表明,MeJA处理7 d后,烷类、二级醇类、酮类、醛类含量以及蜡质总量与对照相比均显著增加,而处理14 d后,所有蜡质组分含量及蜡质总量与对照相比均显著减少;SA与ACC处理早期对叶片蜡质沉积无显著影响(SA处理14 d后,一级醇类、醛类及未知组分含量显著减少)。SA、MeJA和ACC处理21 d后均显著诱导油菜叶片角质层蜡质的沉积,蜡质组分中烷类、酮类、醛类显著增加,其中C29烷、C29酮、C30醛是被SA、MeJA和ACC诱导的主要蜡质组分,暗示烷类、酮类、醛类可能与这些信号分子介导的抗(耐)性反应密切相关。扫描电镜结果显示,SA处理减少叶表皮蜡质杆状结构,且部分区域熔融;MeJA与ACC处理增加油菜叶表皮蜡质的晶体结构密度。角质层蜡质的沉积与结构变化降低角质层渗透性,减缓叶片的水分散失,其中C29烷的特异性增加可能是造成叶片失水率降低的主要原因。     

提取方法对库尔勒香梨果实表皮蜡质提取效果的影响

以库尔勒香梨为试材,三氯甲烷和正己烷为提取剂,采用常温法、加热法和常温加热组合法提取香梨果实表皮蜡质,探讨香梨果皮蜡质的提取方法,为研究香梨果皮蜡质结构及成分提供基础。结果表明：以三氯甲烷为提取剂的效果明显优于正己烷,采取常温结合加热法提取表皮蜡质的含量最高,常温法提取的蜡质含量最低。扫描电镜观察结果表明：采用常温加热结合法,以三氯甲烷作溶剂可充分提取香梨表皮蜡质,而正己烷提取果实表皮呈不明显网状结构,仍有晶体残留;采用加热法,以三氯甲烷提取香梨果实表皮蜡质后,表皮蜡质有小部分残留,而正己烷提取后残留晶体较三氯甲烷提取后多,有不规则的小粒状晶体残存;用常温法则两种溶剂均不能将香梨表皮蜡质提取干净。综合提取蜡质含量和扫描电镜分析的结果得出,以三氯甲烷为溶剂、采用常温加热结合法是有效且易行的提取库尔勒香梨表皮蜡质的方法。     

逆境处理下水稻叶角质层蜡质积累及其与蜡质合成相关基因OsGL1表达的关系

植物角质层蜡质在抵抗各种生物和非生物胁迫中起着非常重要的作用。本试验以水稻(Oryza sativa L.)幼苗为材料, 分别以200 mmol L^-1 NaCl、12% PEG、1.0% H₂O₂、40℃高温和8℃低温为逆境, 研究叶角质层蜡质的积累情况以及其与水稻蜡质合成相关基因OsGL1表达的关系。扫描电镜观察以及叶角质层蜡质总量测定结果表明, 12% PEG、1.0% H₂O₂和8℃低温处理下水稻幼苗叶角质层蜡质的积累明显增加, 而200 mmol L^-1 NaCl和40℃高温处理下叶角质层蜡质覆盖量略有下降。RT-PCR分析显示, 逆境处理下水稻蜡质合成相关基因OsGL1的表达量变化与水稻幼苗叶角质层蜡质的积累存在相关性。     

1-MCP和货架温度对“乔纳金”苹果贮后品质的影响

为了提高"乔纳金"苹果货架期间的商品价值,减少货架损失,本试验将苹果经1-甲基环丙稀(1-MCP)处理后置于(0±1)℃冷库贮藏3个月,然后存放于不同的货架温度(5、10、15、20℃),研究不同货架温度对1-MCP处理后果实感官品质和营养特性的影响。结果表明:经过3个月的贮藏,"乔纳金"苹果果实品质下降较快,未经1-MCP处理的对照组货架时间短,果实硬度低,1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力下降快,适合短期贮藏,以5℃和15℃货架温度货架放置8 d较好;1-MCP处理可以较好地维持"乔纳金"苹果贮藏期间较高的品质,有效地延迟货架期果实品质的下降,从综合效果来看,1-MCP处理组在短期8 d货架时间,可以放置在15℃较高温度下,而长期货架放置(24 d)时,在低温5℃和10℃条件下苹果的感官和品质较好。本研究结果为"乔纳金"苹果的贮藏保鲜和货架期的选择提供了技术支持。     

1-MCP和货架温度对“乔纳金”苹果贮后

为了提高“乔纳金”苹果货架期间的商品价值,减少货架损失,本试验将苹果经1-甲基环丙稀（1-MCP）处理后置于（0±1）℃冷库贮藏3个月,然后存放于不同的货架温度（5、10、15、20 ℃）,研究不同货架温度对1-MCP处理后果实感官品质和营养特性的影响。结果表明：经过3个月的贮藏,“乔纳金”苹果果实品质下降较快,未经1-MCP处理的对照组货架时间短,果实硬度低,1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除能力下降快,适合短期贮藏,以5 ℃和15 ℃货架温度货架放置8 d较好;1-MCP处理可以较好地维持“乔纳金”苹果贮藏期间较高的品质,有效地延迟货架期果实品质的下降,从综合效果来看,1-MCP处理组在短期8 d货架时间,可以放置在15 ℃较高温度下,而长期货架放置（24 d）时,在低温5 ℃和10 ℃条件下苹果的感官和品质较好。本研究结果为“乔纳金”苹果的贮藏保鲜和货架期的选择提供了技术支持。     

采后外源钙对甜樱桃货架品质的控制

为探明外源钙对甜樱桃采后货架期品质的影响,以晚熟品种"晚红珠"为研究试材,经不同浓度CaCl2(1.5%、2.5%)浸果5 min处理后,在货架条件(18~20℃)下存放,并测定其相关商品指标变化。结果表明:不同浓度CaCl2处理在货架期6 d内,可显著控制果实腐烂率和失水率的下降,保持果面色泽亮度和饱和度,维持果实硬度、减缓果实软化,延缓果实花青苷的合成以及保持果柄持绿程度。其中,1.5%CaCl2处理组在各个取样时间点测得的腐烂率和失水率均显著低于对照组(P<0.05),模拟货架条件下放置6 d内,腐烂率和失水率分别控制在5%和2.5%以内;2.5%CaCl2处理,在模拟货架条件下放置12、15 d时,硬度较对照组分别高17.0%、19.0%。因此,综合以上指标,1.5%CaCl2处理对甜樱桃货架期的延长具有显著效果。本研究为CaCl2在甜樱桃采后货架期保鲜技术中的应用提供了理论依据。     

1-MCP对苹果后熟及衰老的影响

研究1-MCP(1-甲基环丙烯)处理对苹果果实呼吸强度、硬度、叶绿素、可滴定酸、可溶性固形物含量以及果实外观和风味的影响。试验表明,1-MCP可明显降低苹果果实呼吸强度,延迟果实呼吸高峰出现,减缓果实硬度和酸度下降,减少果皮叶绿素分解,同时还明显地抑制了果实衰老,对延长“津轻”苹果的货架寿命,保持果实的货架期质量起到重要的作用。     

植物果实角质层及其渗透性的研究进展

综述了植物果实角质层多种分离方法及其适用范围,角质层的主要化学组成、结构及其生理作用,角质层蜡质组成和含量及其在果实生长过程中的变化对植物渗透性的影响,并展望了植物果实角质层渗透性研究的应用前景,以期为角质层的仿生学研究提供理论支撑。     

The fruit cuticle as a modulator of postharvest quality

The composition and structure of fruit surface tissues have a noticeable influence on the postharvest storage potential of fruit, inasmuch as they behave as a barrier against drying, chemical attack, mechanical injuries and microbial infection. The cuticle is made of cutin, a biological insoluble polyester, embedded in an impermeable wax complex, and its inner side interacts intimately with the underlying epidermal cell walls. The cuticle plays a decisive role in plant development, being the first communication system with the surrounding biotic and abiotic environment. Published reports on the composition and biosynthesis of fruit cuticles are comparatively scarce, and many knowledge gaps exist on the part cuticles play in quality determination and postharvest performance. This review aims at collecting available information in relation to the role of the fruit cuticle as a determinant factor of some important traits related to postharvest quality, including water loss, susceptibility to physical and biological stresses, and decreased fruit firmness. To the best of our knowledge, this is the first published work focusing on the fruit cuticle as a major modulator of postharvest quality and interlinking existing dispersed literature on this topic. A deeper understanding of cuticle structure and function will be of help in understanding postharvest biology and in designing new technological solutions.     

纳米果蜡和1-MCP处理对“新红星”苹果贮藏效果的影响

以"新红星"苹果为试材,在常温条件下分别研究了果蜡涂膜保鲜,1-甲基环丙烯(1-MCP)熏蒸,以及1-MCP与果蜡涂膜保鲜共复合处理的贮藏效果。结果表明,1-MCP与果蜡涂膜的复合处理能有效地降低"新红星"苹果的质量损失率,抑制果实硬度、可溶性固形物和可滴定酸含量的下降,降低其呼吸强度及乙烯释放量,延缓果实衰老,较好地保持了果实在采后贮藏期间的品质。     

莲雾保鲜研究进展

莲雾是一种有着独特风味及外形的热带水果,其营养价值丰富,口感十分清爽。但是莲雾采收后呼吸强度大、代谢旺盛、水分损失快,会快速失去商品价值,因此莲雾极不耐贮藏的问题给果农带来了很大的损失。本文综述国内外文献,从物理方法、化学方法、生物方法等三个方面,阐述莲雾贮藏保鲜最新研究进展,并对莲雾贮藏保鲜的研究方向和莲雾产业的发展进行了展望。     

Characterization and genetic mapping of eceriferum-ym (cer-ym), a cutin deficient barley mutant with impaired leaf water retention capacity

The cuticle covers the aerial parts of land plants, where it serves many important functions, including water retention. Here, a recessive cuticle mutant, eceriferum-ym (cer-ym), of Hordeum vulgare L. (barley) showed abnormally glossy spikes, sheaths, and leaves. The cer-ym mutant plant detached from its root system was hypersensitive to desiccation treatment compared with wild type plants, and detached leaves of mutant lost 41.8% of their initial weight after 1 h of dehydration under laboratory conditions, while that of the wild type plants lost only 7.1%. Stomata function was not affected by the mutation, but the mutant leaves showed increased cuticular permeability to water, suggesting a defective leaf cuticle, which was confirmed by toluidine blue staining. The mutant leaves showed a substantial reduction in the amounts of the major cutin monomers and a slight increase in the main wax component, suggesting that the enhanced cuticle permeability was a consequence of cutin deficiency. cer-ym was mapped within a 0.8 cM interval between EST marker {"type":"entrez-nucleotide","attrs":{"text":"AK370363","term_id":"326489160","term_text":"AK370363"}}AK370363 and {"type":"entrez-nucleotide","attrs":{"text":"AK251484","term_id":"151420132","term_text":"AK251484"}}AK251484, a pericentromeric region on chromosome 4H. The results indicate that the desiccation sensitivity of cer-ym is caused by a defect in leaf cutin, and that cer-ym is located in a chromosome 4H pericentromeric region.     

氢化物发生原子荧光光谱法测定果蜡中总砷的含量

建立了一种采用氢化物发生原子荧光光谱法测定果蜡中总砷含量的有效方法。该方法最低检出限为0.023ng/mL,RSD为0.52%。柑橘专用果蜡总砷含量为(0.048±0.005)mg/kg,苹果专用果蜡总砷含量为(0.024±0.002)mg/kg,加标回收率为95.45%～100.16%。实验表明,此法操作简便,灵敏度高,重现性好。     

Potassium sorbate effects on citrus weight loss and decay control

Potassium sorbate (PS) is a well-known and widely used food preservative. Among other applications, it is used as a GRAS fungistatic postharvest treatment for citrus, although its use is not free of significant adverse effects. In this paper, we study in detail the efficacy of wax containing increasing concentrations of PS to control Penicillium digitatum decay in citrus fruit, and its effect on fruit weight loss. Decay control and weight loss increased with the concentration of PS in the wax. Wax with typical amounts of 2–5% PS showed poor decay reduction indices (DRI), between 26% and 32%, whereas fruit weight loss increased compared with non-waxed controls. Waxing of fruit reduced weight loss by up to 40%, depending on wax formulation, but the addition of just 2% PS to the wax caused an increase in fruit weight loss of up to 65% compared with the waxed fruit. Similar results were observed for all the types of wax formulations tested. The hygroscopic effects of PS are even more damaging for citrus fruit with leaves. The leaves lose weight very rapidly when PS is added to the wax and they become desiccated in 24 h.We also present the results of a similar study where PS was applied to citrus as an aqueous treatment. When applied in water, PS was far more effective for decay control than when applied in wax, but there was also a considerable increase in fruit weight loss. A treatment combining aqueous PS with Fortisol^® Ca Plus biostimulant completely solved the problem of weight loss, these mixtures being commercially feasible treatments.     

Managing biological variation in skin background colour along the postharvest chain of ‘Jonagold’ apples

Skin background colour is an important quality aspect in the grading of ‘Jonagold’ apples, with consumers usually preferring fruit with a green background colour. However, apple handlers are usually faced with large fruit-to-fruit variability of background colour within a population of fruit. In this study, a stochastic modelling approach was used to describe how the initial fruit-to-fruit variability in the background colour of ‘Jonagold’ apples present at harvest, propagates throughout the postharvest chain. Two hundred and twenty ‘Jonagold’ apple fruit were harvested and stored at 1 °C or 4 °C, under different controlled atmosphere (CA) conditions for 6 months, followed by 2 weeks exposure to shelf-life conditions, during which the background colour and ethylene production of the individual fruit were measured. A kinetic model was developed to describe the postharvest loss of skin greenness, by assuming that the loss was principally due to chlorophyll breakdown, the rate of which was dependent on the endogenous ethylene concentration. Stochastic model parameters were identified, and by treating these parameters as fruit-specific, the model could account for more than 95% of the variability of the data. By treating the stochastic model parameters as random factors, the Monte Carlo method was used to model and describe the propagation of the fruit-to-fruit variability of the background colour within a population of fruit. The model developed in this study might allow better management of variability in quality along the postharvest chain, by predicting how the initial fruit-to-fruit variability within a batch of apples will propagate throughout the postharvest chain, as a function of storage and shelf-life conditions.     

套袋对白水县苹果质量及效益的影响

白水县是陕西苹果的最佳优生区,套袋苹果已占苹果生产总量的65.54%,是无公害苹果生产的关键技术之一,研究套袋技术对苹果生产具有重要的指导意义。项目对白水县苹果套袋情况进行了系统的调查,并就生产中三种果袋对苹果外观质量、内在质量、果实黑点病发生情况、效益等进行了研究。研究结果表明：目前生产中应用较多的仍然是双层双色纸袋和单层双色劣质纸袋,果实套袋能显著提高果实光洁度、着色度、果实外观鲜艳,降低VC含量,增加黑点病发病率,其中套双层三色优质纸袋苹果黑点病发病率轻,为5.2%,而套单层双色劣质纸袋重,高达47.7%,套袋能显著提高苹果生产的经济效益