制冷贮藏温度对锦橙的影响

以锦橙为材料,研究不同制冷温度对贮藏效果和锦橙品质的影响。结果表明,温度明显影响着锦橙的腐烂率和褐斑病率,温度6～8℃下贮藏150d锦橙的腐烂率和褐斑病率最低,分别为5.40%和5.41%;温度是影响失质量率的重要因素,制冷贮藏的失质量率低于通风贮藏;温度是影响锦橙果实呼吸代谢的重要因素,果实的呼吸强度随温度的降低而明显降低;果实有机酸含量随温度降低而明显提高,总糖含量的变化规律与有机酸基本相同;低温贮藏也可降低VC、可溶性固形物的损耗;贮藏温度过高,病菌性腐烂率高,品质下降快,而温度过低则产生冷害型腐烂,果皮不能正常转色,认为锦橙长期贮藏的适宜温度为6～8℃。     

芦荟对锦橙贮藏保鲜效果的影响

试验采用芦荟汁处理锦橙果实,探索芦荟在水果保鲜上的作用.结果表明,用芦荟汁处理的果实酸度、VC、可溶性糖、可溶性固形物含量的保存率分别比对照高21.39%、6.88%、29.05%、6.18%;果实腐烂率与水分散失率分别比对照降低11.30%、0.63%;果实代谢增强,而相对电导率降低,芦荟对锦橙果实具有保鲜效果.     

温室条件下杏果实发育过程中糖、酸和Vc含量的变化

通过对温室条件下杏(金太阳、凯特)果实发育过程中可溶性糖(还原糖、非还原糖)、有机酸和维生素C含量的测定,系统分析了它们在整个生长发育过程中的动态变化。可溶性糖总量随果实的生长而增加,但还原性糖与非还原性糖变化趋势相反。有机酸含量幼果期较高,硬核期降低,之后有一次高峰,成熟时降至最低。维生素C含量,幼果期、成熟期较高,硬核期较低,且呈“V”型变化曲线。果实中糖、酸和维生素C的变化与果实的生长期有一定的关系,非还原性糖、有机酸和维生素C在果实硬核期含量都最低。     

施硒对‘荷兰86-13’和‘月脂’黄瓜品质影响

为研究施硒浓度对黄瓜硒含量及品质的影响,以‘荷兰86-13’黄瓜和‘月脂’黄瓜为试验材料,采用叶面喷施方法对黄瓜硒含量、维生素C、可溶性糖、可溶性固形物、有机酸等品质进行研究。结果表明,硒含量随施硒浓度的增加而增加。施硒浓度7.5 g/hm2的‘荷兰86-13’黄瓜维生素C含量增长显著,可溶性固形物含量增长率为22.22%,钾含量增长率为27.16%;施硒浓度7.5 g/hm2的‘月脂’黄瓜维生素C含量提高了8.2%,可溶性糖含量提高了12.98%,钾含量降低率达32.06%,施硒处理对其有机酸、蛋白质、粗纤维和钙含量影响不显著。因此,适当的施硒浓度可以显著提高黄瓜的维生素C、可溶性糖、可溶性固形物等品质,但施硒处理对于‘月脂’黄瓜对钾的吸收表现为抑制作用。     

离子色谱法测定贮藏期间菠萝果实的糖分变化

优化了应用离子色谱检测巴厘菠萝果实糖分组成与含量的方法,经优化的测定分析条件为：Carb0PacPAl（2×250mm）分离柱,淋洗液40mmol／LNaOH溶液,流速0．25mL·min^-1,柱温30℃;用该方法对经果蜡处理的巴厘菠萝果实贮藏期间的糖分组成和含量进行了有效分离与测定。结果表明,果蜡处理组与对照组菠萝果实的糖分都是以蔗糖为主,其次为葡萄糖和果糖;贮藏期间,处理与对照组果实主要的3种糖含量均呈不断下降趋势．但果蜡处理组果实的葡萄糖和蔗糖含量总体上明显高于对照．表明果蜡处理对保持菠萝采后品质有一定作用。     

不同果蜡处理对默科特柑橘常温贮藏效果的影响

以默科特柑橘(Murcott)果实为试材,研究了三种果蜡(Decco Fruitshine 402F、FMC890、自制果蜡)处理对其常温(20℃)条件下贮藏22 d的保鲜效果。结果表明,三种果蜡处理均能有效减少果实的失重,显著降低油胞下陷率;402F和FMC890果蜡处理可明显提高果实亮度;自制果蜡处理的果实失重率最低,硬度最高,并可较好地保持果实的原有风味。     

有机酸、EDTA配施对铅胁迫蒜苗部分生理特性及品质的影响

通过对蒜苗的部分生理指标和品质指标的分析,研究了外援有机酸（草酸、柠檬酸）和EDTA对铅胁迫蒜苗的缓解效应。结果表明,用有机酸、EDTA处理铅污染土壤,能明显调节蒜苗的生长发育,使蒜苗叶片叶绿素含量提高,根系活力得到一定程度地增强,维生素C、糖分和大蒜素的含量都明显提高,铅含量显著降低。     

春大棚12个牛角椒品种比较试验

正辣椒别名番椒、海椒、秦椒、辣茄,为茄科辣椒属植物,果实含有丰富的蛋白质、糖、有机酸、维生素及钙磷铁等矿物质,其中维生素C含量极高,胡萝卜素含量也较高,还含有辣椒素,可增进食欲帮助消化。牛角椒(长辣椒)作为辣椒的一个变种,以采收鲜果烹饪为主要食用方法,深受消费者喜欢,近几年栽培面积不断扩大,是北京地区春季设施栽培的主要茄果类蔬菜之     

新梨7号和早酥梨果实发育过程中主要营养成分的变化

以新梨7号和早酥梨两个梨品种的果实为试材,进行果实发育过程中单果重、果实纵横径变化及主要营养成分（有机酸、可溶性糖、维生素C等）含量的分析。结果表明：早酥梨和新梨7号单果重的变化曲线呈“慢-快-慢”的单“S”型,新梨7号果实纵横径的日增长量呈现3个高峰,早酥梨有2个高峰;可溶性糖含量不断增加,有机酸含量和游离氨基酸含量随果实成熟逐渐减少;果实维生素C含量和可溶性蛋白含量变化呈“降-升-降”的变化趋势。     

不同缺素处理对库尔勒香梨果实品质的影响

在田间条件下,对20年树龄库尔勒香梨设置不同缺素的施肥处理,研究营养元素缺乏胁迫下库尔勒香梨果实品质的变化。结果表明：施肥能明显促进香梨果实的生长发育,提高单果重和产量;改善香梨果实形状,提高香梨红晕果率及果实中还原糖和维生素C的含量;降低香梨果皮厚度、果实硬度及果实中总酸的含量。香梨果皮厚度、果实硬度、单果重和产量的施肥效应N＞K＞P;果形指数、红晕果率及果实中还原糖和维生素C含量的施肥效应K＞P＞N;果实中总酸含量的施肥效应N＞P＞K。     

外源SA影响油菜叶表皮蜡质及菌核病抗性的机制

处于植物地上部分最外层的表皮蜡质被认为是植物抵御病原物入侵的第一道屏障,但表皮蜡质是否及如何参与油菜菌核病防御机制还不清楚。本试验选用2个抗病性不同的油菜品种中双9号(抗性品种)和渝油19 (感病品种),对水杨酸(SA)处理后的油菜幼苗接种核盘菌,分析油菜病情指数、叶表皮蜡质含量和晶体结构特征、抗氧化酶活性的变化规律。结果表明,SA处理使中双9号病情指数显著下降,渝油19无显著变化,SA诱导了油菜抗性品种中双9号对菌核病的抗性。接种核盘菌后,中双9号PAL活性显著增加,而渝油19显著下降; SA处理植株叶片PAL和POD活性显著高于单纯接种植株。渝油19苗期叶表皮蜡质总量显著高于中双9号。SA诱导中双9号蜡质总量及组分含量增加,柱状晶体结构减少,片状结构增加,扩大了蜡质层覆盖叶表面积。渝油19在SA处理后蜡质含量无显著变化,晶体结构发生了与中双9号相似的变化,但渝油19蜡质晶体熔融后覆盖叶表面积小于中双9号。综合分析认为防御酶活性及叶表皮蜡质共同参与SA诱导中双9号抗性增强的过程。     

Storage performance of Fortune mandarins following hot water dips

Commercially ripe ‘Fortune’ mandarins were dipped in water at 50 °C (Dip50), 52 °C (Dip52), 54 °C (Dip54), 56 °C (Dip56), or 58 °C (Dip58) for 3 min before storage at 6 °C for 30 days and 3 additional days at 20 °C (simulated shelf-life). Untreated fruits were used as control. Scanning electron microscopy of untreated fruit revealed rough and granular wax surface structures with a number of deep surface cracks. In contrast, fruits dipped at 50–54 °C did not exhibit similar fractures and the fruit surface appeared relatively homogeneous. Dip56 resulted in parts of the surface with no apparent epicuticular wax and zones with an accumulation of waxy deposits. With Dip58, the fruit surface appeared as if the treatment had melted and completely removed epicuticular waxes. Dip50–54 reduced chilling injury and levels of decay, both during cold storage and simulated shelf-life. Dip56–58 showed no advantages compared with untreated fruit. Neither Dip50 nor Dip52 caused adverse effects to rind surface, either during or after simulated shelf-life. Conversely, higher dip temperatures induced heat damage in the form of rind browning, the extent and number of fruits affected increasing as bath temperature increased. Water loss was consistently lower in untreated fruit. Peel water loss was consistently higher in Dip56 and Dip58 fruit. Differences in external appearance, physiological behaviour and internal quality attributes between untreated and Dip50–54 fruit were minimal. Dip56 and especially Dip58 had negative effects on the external appearance of fruits. The off-flavour found in Dip58 was probably due to increased levels of ethanol in the juice.     

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。     

Epicuticular wax content and morphology as related to ethylene and storage performance of ‘Navelate’ orange fruit

The effect of ethylene (2 μL L⁻¹) on total and soft epicuticular wax content and wax morphology has been investigated in mature ‘Navelate’ (Citrus sinensis, L. Osbeck) oranges held under non-stressful environmental conditions (22 °C and constant high relative humidity (90–95% RH)). In addition, the objective of the study was to understand whether the ethylene-induced changes in epicuticular wax might participate in the beneficial effect of ethylene reducing non-chilling peel pitting, by modifying peel water, osmotic or turgor potential, or disease incidence caused by Penicillium digitatum (Pers.:Fr.) Sacc. Ethylene increased total and soft epicuticular wax content in ‘Navelate’ fruit and induced structural changes in surface wax that might be related to the formation of new waxes. Changes in epicuticular wax morphology, but not in its content, might be involved in the protective role of ethylene reducing non-chilling peel pitting, although the beneficial effect of the hormone is not related to water stress. Cell water and turgor potentials in freshly harvested fruit and fruit stored in air under non-stressful conditions suggest that water stress is not a limiting factor leading to the development of this physiological disorder. In addition, the results indicated that formation of new waxes in fruit treated with ethylene may partially cover stomata, cracks or areas lacking wax occurring in stored fruit and is likely to improve physical barriers to P. digitatum penetration.     

水热胁迫对紫花苜蓿叶表皮蜡质组分及生理指标的影响

选用2个抗旱性不同的紫花苜蓿品种,敖汉(强抗旱)和三得利(弱抗旱),在水热胁迫条件下,调查其叶表皮蜡质含量及组分变化规律、蜡质含量与气体交换参数、脯氨酸及叶片相对含水量之间的关系。结果表明,紫花苜蓿叶表皮存在致密的蜡质层,蜡质晶体结构呈片状,无特殊的晶格方向。叶表皮蜡质主要由烷(1.98%~3.38%)、醇(79.97%~84.98%)、酯类(0.08%~0.24%)及其他少量未知物质组成(7.77%~13.38%)。品种类型、环境条件共同影响叶表皮蜡质的沉积。敖汉叶表皮蜡质含量显著高于三得利。水分胁迫后烷类比例增加(81.22%~108.16%),醇类比例下降(3.32%~12.54%),强抗旱品种叶表皮蜡质含量和气体交换参数无显著变化(除胞间二氧化碳浓度显著下降外),而弱抗旱品种蜡质含量和叶片光合速率、蒸腾速率、气孔导度及胞间二氧化碳浓度均显著下降。说明表皮蜡质限制水分散失,蜡质组分中烷类物质可能主要具限制水分散失的功能。高温及水热互作胁迫处理下,紫花苜蓿叶片光合速率和蒸腾速率下降,水分利用效率提高,叶片脯氨酸含量增加,相对含水量下降,敖汉蜡质含量下降,三得利蜡质含量无显著变化。表明在严重胁迫条件下紫花苜蓿主要通过关闭气孔和渗透调节来限制水分散失。     

Leaf Waxes of Cassava (Manihot Esculenta Crantz) in Relation to Ecozone and Resistance to Xanthomonas Blight

Summary To elucidate the role of leaf surface structures as first barriers to confer resistance to bacterial blight, leaf stomata and their occlusion with leaf waxes were studied in cassava genotypes. For the first time, cassava leaf waxes were quantitatively and qualitatively analysed. Comparing the susceptible and resistant standard genotypes BEN86052 and TMS30572, respectively, the total quantity of triterpenes was significantly higher in the resistant genotype, grown in three ecozones of Benin. In cuticular leaf waxes of seven cassava genotypes the triterpenes beta amyrins, epi-taraxerol, taraxerone and taraxerol were dominant constituents across genotypes, and alkanes (C₂₅-C₃₃) and acids (C₃₀ and C₃₂) occurred in minor concentrations. Comparing seven genotypes, no clear relation between resistance or ecozones and total quantities of the major wax constituents was observed. Only the highly resistant genotype TMS30572 showed high triterpene levels irrespective of ecozone. Scanning electron-microscopy revealed a regular distribution of waxes at the abaxial leaf surface, covering and occluding stomatal pores of susceptible and resistant genotypes, while on the adaxial leaf surface waxes were in form of crystalloids and did not occlude the stomata. The number of stomata on the abaxial surfaces was about 7–11 fold higher than on the adaxial surfaces, where stomata were located along the midrib and major veins. No significant differences in stomata number were observed between genotypes varying in resistance to bacterial blight. It is suggested, that stomata on the adaxial surface might be portals of entry for the bacteria.     

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。     

不同品种芒果贮藏性状的比较及对热处理的反应

为解决芒果采后易软化、变黄和腐烂等问题,以‘台农’、‘红贵妃’和‘金煌’3个品种芒果为实验材料,分别进行热处理（50℃热水处理10 min）,并比较其作用效果。发现热处理能维持果实的硬度,但对糖、酸和Vc的含量无显著的影响,能抑制MDA的产生,但不能抑制芒果的细胞膜透性的增加。不同品种之间,从硬度和可滴定酸的保持以及低电导率、低MDA含量和较高SOD活性的保持,都充分说明了‘红贵妃’的耐贮性好于‘台农’和‘金煌’2个品种。     

Changes in cuticular waxes of developing leaves in sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is one of the most important oil seed crops, which has been used as a traditional health food. The objective of this study was to investigate the changes of leaf cuticular waxes during plant growth from 5 to 75 days after seedling emergence, and the variation of leaf waxes with different leaf position; top, middle, and lower positions, using four Korean sesame cultivars, Ahnsan, Danbaeck, Hanseom, and Kyeongheuk. Alkanes in lower leaves and aldehydes in top leaves among leaf positions were the most abundant, with alkanes being with major portion in all leaf position of four sesame cultivars. Total leaf wax load decreased around three-fold between 5 and 30 days, and then remained constant up to day 75. The percentages of alkanes and aldehydes increased between 5 and 15 days and then changed little or increasingly, showing minor variation depending on sesame cultivars. The rate of increase of alkanes was slightly higher than that of aldehydes. Chain length of alkanes and aldehydes became longer from 5 to 30 days, and then remained almost constant till day 75. The major homologue in alkanes was the C29 at day 5 and the C33 constituent after day 30, while the major homologue in aldehydes was the C32 constituent continuously during leaf development. The results demonstrated that the chain length for alkane and aldehyde constituents changed increasingly by chain elongation and wax biosynthesis during leaf development of sesame.     

旗叶蜡质含量不同小麦近等基因系的抗旱性

于2013-2014和2014-2015年度,以多蜡质和少蜡质的4个小麦近等基因系为材料,采用田间旱棚方式控制土壤水分,研究了蜡质含量与小麦抗旱性的关系。结果表明,干旱处理后,多蜡质小麦品系旗叶的蜡质含量平均为15.15 mg g?1,较少蜡质小麦品系(8.43 mg g?1)高79.8%;多蜡质小麦品系旗叶的水势较高,干旱处理后下降幅度明显小于少蜡质小麦品系,水分散失率也显著低于少蜡质品系(P< 0.05);多蜡质小麦品系旗叶的光合速率平均下降7.5%,而少蜡质小麦品系下降9.8%;多蜡质小麦品系旗叶PSII最大光化学效率(Fv/Fm)平均下降幅度为3.4%,少蜡质小麦品系下降幅度达到5.8%;多蜡质小麦品系的籽粒产量高于少蜡质品系,平均高3.7%;多蜡质小麦品系的抗旱指数和干旱敏感指数均显著低于少蜡质小麦品系(P< 0.05)。以上结果表明,蜡质能够提高小麦的抗旱性,旗叶蜡质含量可以作为抗旱小麦品种的选择指标。