盐肤木果油中没食子酸的UPLC-MS及HPLC分析

盐肤木果实中没食子酸等多酚类物质是重要的生物活性成分，具有抗氧化、抗病毒、消肿瘤等多种生物学活性。采用超高效液相色谱-质谱联用技术（UPLC-MS），分别对压榨法、乙醚浸提法和超临界CO2萃取法3种提取方法所得盐肤木果油中没食子酸等多酚成分进行了定性分析，再以没食子酸标准品为对照，采用高效液相色谱法（HPLC）对各样品中没食子酸含量进行了定量分析。结果表明：3种样品中均检测到没食子酸的存在，其含量在69.5～434.4 mg/L之间，但不同样品中没食子酸含量差异显著，即提取盐肤木果油的方式不同，其油脂中含没食子酸的多少不同，其中以乙醚浸提油中样品中没食子酸最多，达(426.7±7.7)mg/L。该研究可为进一步开发利用盐肤木果油资源提供方法借鉴。     

干旱胁迫下黑果枸杞幼苗对外源水杨酸的生理响应

以黑果枸杞(Lycium ruthenicum)幼苗为试验材料,采用控制水分梯度模拟干旱胁迫条件,研究在不同程度干旱胁迫下黑果枸杞幼苗对外源水杨酸(SA,0.1、0.5 mmol·L-1)的生理响应。结果表明:在干旱胁迫及喷施SA的条件下,渗透调节物质随着胁迫程度的加大,有显著增长;MDA含量随着干旱胁迫程度的增加而递增,而在喷施SA的情况下,MDA含量比各自未喷施SA对照有所下降;SOD、POD、CAT活性在轻度胁迫下有所増高,喷施SA后,中重度干旱胁迫的抗氧化酶活性升高并高于对照。说明干旱胁迫对黑果枸杞生理生化指标有一定的影响,喷施外源水杨酸能增强黑果枸杞的抗旱能力。     

根系输液改善妃子笑荔枝钙营养的研究

在妃子笑果实膨大期,用CaCl2进行根系输液、果实蘸果及树冠喷施三种不同的补钙处理,研究不同补钙方式对改善妃子笑荔枝钙营养的作用。结果表明,用CaCl2根系输液,能够显著改善树体钙素营养,果皮和叶片的钙含量比对照分别提高了85.19%和50.28%,效果显著好于树冠喷施和果实浸蘸。与对照相比,果实浸蘸、树冠喷施也有显著改善钙营养的作用,果皮和叶片的钙含量比对照分别提高了33.48%、8.85%和28.43%、51.54%。综合比较三种补钙方式的效果,根系输液好于蘸果,蘸果处理好于树冠喷施。     

苜蓿叶片水杨酸含量与其蓟马抗性的关系

采用不同抗蓟马特性的苜蓿品系,于不同蓟马虫口密度下测定苜蓿水杨酸含量和虫害程度,以明确苜蓿叶片水杨酸含量与其抗蓟马特性的关系.结果表明,苜蓿叶片游离态、结合态水杨酸含量均与苜蓿抗蓟马特性密切相关;高抗品系(抗蓟马品系)的水杨酸初始含量(0.539 mg·g-1)高于低抗品系(0.403 mg·g-1);与较低抗品系相比,高抗品系受害器官(叶)水杨酸含量随虫口密度和危害点面积的增大而增加相对缓慢,而随危害指数的增大而增加较快(3.84倍).可见,水杨酸主要是间接增强苜蓿对蓟马的抗性;高抗蓟马苜蓿品系能通过快速获得较高水杨酸含量来阻碍被危害伤口的扩大,降低其受危害程度,促使自身产量和品质提高.     

在伤信号传导中茉莉酸与水杨酸的关系

近年来,发现茉莉酸和水杨酸都是植物体对外界伤害作出反应,表达抗性基因的信号分子。水杨酸可抑制茉莉酸类的合成及其所诱导的蛋白基因的表达;茉莉酸能阻止病原侵染后所产生的水杨酸的增加。茉莉酸信号转导途径和水杨酸信号转导途径存在着交叉,小GTP结合蛋白和细胞分裂素可能起着信号开关的作用。     

苗期喷施水杨酸对甜叶菊主要农艺性状和糖苷含量的影响

采用不同浓度水杨酸(0.5、1、2、4、8mmol·L~(-1))以及水杨酸抑制剂1-氨基苯并三唑(ABT)10μmol·L~(-1)喷施大棚内以及大田中甜叶菊苗期叶片,探究其对甜叶菊主要农艺性状、叶片糖苷含量以及采收时期甜叶菊叶片水杨酸含量的影响。结果表明:(1)随着水杨酸处理浓度升高,大棚和大田中甜叶菊主要农艺性状大多均表现出先增加后降低的趋势;2mmol·L~(-1)水杨酸处理下,大棚内和大田中甜叶菊主要农艺性状均有显著增加,其单株叶干重产量分别为1.03和16.76g较对照(0.76和12.34g)增加39.96%和9.52%;ABT处理对甜叶菊农艺性状均有一定抑制作用。(2)甜叶菊叶片总糖苷及其组分含量在1mmol·L~(-1)水杨酸处理后均有明显升高,且在2mmol·L~(-1)水杨酸浓度下达到最高值,此时大棚和大田中甜叶菊叶片总糖苷含量分别为16.75%、14.57%比对照(13.33%、12.03%)增加25.66%和16.18%,RA苷也均有显著增加并达到10.59%和9.77%。(3)采收时期大田甜叶菊叶片水杨酸含量在1和2mmol·L~(-1)处理后与对照组无显著差异,在4和8mmol·L~(-1)水杨酸处理后显著提高,而在ABT处理后有所降低。研究认为,叶面喷施适宜浓度水杨酸可显著提高甜叶菊产量和糖苷含量,尤其是RA苷含量,且不影响采收期叶片水杨酸含量,生产中可采用2mmol·L~(-1)水杨酸苗期喷施甜叶菊以提高产量和改进品质。     

光果甘草营养器官不同季节总黄酮消长规律的研究

利用紫外分光光度法对二年生栽培光果甘草不同营养器官、不同季节中总黄酮含量的消长规律进行分析研究,以探索光果甘草中总黄酮含量的消长规律,为生产中确定合理的采收期及其采收部位提供依据。结果显示:不同营养器官中,二年生栽培光果甘草总黄酮含量的高低顺序为:上部叶>中部叶>毛状根>水平根茎>侧根>主根、垂直根茎、上部茎>中部茎、下部茎;4～11月,二年生栽培光果甘草总黄酮含量波动较大,6、9、10月含量较高。综合分析表明:叶和毛状根是总黄酮含量最高的部位,二年生栽培光果甘草最佳采收期为早秋;建议对叶采收入药,综合利用光果甘草资源。     

黄冠梨储藏期间果皮PPO和POD酶活性变化与鸡爪病发生关系研究

目的:探明黄冠梨储藏期间鸡爪病发病与PPO和POD酶活性变化关系。方法:①原料预处理:以黄冠梨为试材,分别用2%CaCl2溶液浸泡15 min和1%普鲁兰多糖溶液浸泡5 min处理实验材料,低温冷藏,每隔30天取样一次进行指标测定;②酶活性测定:取两种处理的黄冠梨果皮分别提取PPO和POD并在420 nm下测定PPO活性和470 nm下测定POD活性;③鸡爪病发病情况统计:以病果在总果实中所占比例来说明发病情况。结果:浸钙和普鲁兰多糖涂膜处理黄冠梨,两种处理都不同程度地降低了果皮中PPO活性和POD活性,都延迟了PPO和POD活性高峰的出现,且降低了其峰值,浸钙处理PPO活性最低且一直处于较低水平,PPO活性和POD活性都极显著地低于对照果(P<0.01),但浸钙和普鲁兰多糖处理之间差异不显著(P>0.05)。贮藏末期,对照果发病率为33.33%;浸钙处理果未见发病;普鲁兰多糖涂膜处理果发病率仅为3.33%。浸钙处理效果较好。结论:黄冠梨储藏期间,PPO活性的上升和POD活性的下降,加速了黄冠梨鸡爪病的发生。     

乙烯利对番茄及西瓜的催熟作用

乙烯利(2-氯乙基磷酸)对番茄果实有明显的催熟作用。不管是在植株上喷洒处理,或采收后浸果处理均属有效。采收后浸果处理的浓度,可以从1000—4000ppm,浸果处理时药液温度(20℃及30℃)对催熟的效果影响不大。但在浸果后,要在较高的温度(22—25℃)下,才能获得预期的催熟效果。采收前植株喷洒乙烯利,浓度从500—2000ppm可以提早红熟6—8天,增加红熟果实的早期产量,但对总产量影响不大。这种对产量的一时的增加,主要是增加红熟果实数而不是单果重。在成熟过程中,可溶性固形物变异不大。而可滴定酸度则迅速降低。乙烯利处理对这两种物质的含量只有少量的增加。西瓜在采收前用乙烯利喷果处理,浓度100—500ppm,可提早成熟5—7天,及增加果汁中可溶性固形物的含量。乙烯利处理对果肉各部位的可溶性固形物含量,都比不处理的有相应的增加。     

外源水杨酸对酸雨胁迫后龙眼幼苗生理特性恢复的影响

以龙眼幼苗为材料,研究酸雨胁迫(pH 3.0)后不同浓度外源水杨酸(0、0.1、0.5、1.0和2.0 mmol·L-1)对龙眼幼苗生理特性的影响.结果表明:酸雨胁迫后龙眼幼苗叶片中的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性降低,叶绿素、蛋白质和可溶性糖含量下降,丙二醛含量升高,龙眼幼苗显示出毒害效应.0.1 ～1.0mmol·L-1外源水杨酸显著提高龙眼幼苗叶绿素、可溶性糖和蛋白质的含量,增强SOD、POD和CAT活性,降低丙二醛含量,减少幼苗所受氧化伤害的程度;其中0.5 mmol· L-1水杨酸处理效果最好,叶绿素、可溶性糖和蛋白质的含量分别比单独酸雨胁迫处理植株增加了62％、105％和177％,SOD、POD和CAT活性分别提高144％、440％和132％,丙二醛含量降低了35％;而2.0 mmol·L-1水杨酸却起到相反的作用.可见,低浓度水杨酸(0.1～1.0 mmol·L-1)能通过刺激龙眼抗氧化酶活性,减轻氧化胁迫,缓解酸雨胁迫后的毒害作用,而高浓度水杨酸(2.0 mmol·L-1)对龙眼幼苗的缓解作用下降.     

Effect of eco-safe compounds on postharvest quality preservation of papaya (<Emphasis Type="Italic">Carica papaya</Emphasis> L.)

Early ripening and susceptibility to microbial infection are major postharvest problems in papaya fruits. Being a tropical climacteric fruit, low-temperature storage is not successful in papaya. In this study, we demonstrate the effect of aqueous salicylic acid (1 and 2 mM), nitric oxide (1 and 2 mM), and calcium chloride (1 and 2%) to enhance the papaya shelf life at the ambient conditions with reduced disease incidence. Calcium chloride 2% was the most effective for maintaining postharvest quality. The fruits had good firmness and maintained TSS, acidity, total chlorophyll, free radical scavenging activity and ascorbic acid on the 6th day during ambient storage. Moreover, the weight loss, yellow color development and disease incidence were minimum in calcium chloride 2%, followed by 1% solution of calcium chloride. The nitric oxide (2 mM) maintained higher antioxidant capacity and total phenol content in fruits that was followed by 1 mM salicylic acid during storage. The result suggests that application of calcium chloride 2% could be an easy and effective technique for extending the shelf life without impairing fruit quality during storage.     

Effect of postharvest salicylic acid treatment on fungal decay and some postharvest quality factors of kiwi fruit

The effect of salicylic acid (SA) treatment at different concentrations on fungal decay and some quality factors of kiwi fruit (Actinidia deliciosa var. Hayward) in postharvest conditions were studied. Results experiment showed that SA at all applied concentrations inhibited grey mould growth. The SA application significantly decreased weight loss percentage and increased life storage fruits. Also, SA positively affected on postharvest quality factors including total soluble solids (TSS), titratable acidity (TA), antioxidant, ascorbic acid and pH value. It was observed that treated fruits with SA at concentration 5?mM had the highest TSS, TA, ascorbic acid and antioxidant content and it had the lowest decay and acidity. Thus, these results showed that SA has strong impact on postharvest decay and fruit quality of kiwi fruit.     

Variation in fatty acid composition of apples in relation to soft scald

The distribution of fatty acids within individual fruits was uneven early in storage. When soft scald developed in the fruit, the affected tissue contained less linoleic acid than sound tissue. Differences in fatty acid composition were also found between freshly harvested fruit from different trees within an orchard. Apples that were stored at O° had a low linoleic acid content during the early weeks of storage when the fruit are susceptible to the disorder but the content then increased substantially during subsequent storage. It seems that a low linoleic acid content renders the fruit more susceptible to soft scald.     

采收期对‘红心’番石榴品质和耐贮性的影响

以福建漳州栽培的‘红心’番石榴(Psidium guajava ‘Hongxin’)为材料,探究不同采收期对其果实采后耐贮性和品质的影响。实验分盛花期后95 d (采收期Ⅰ)、105 d (采收期Ⅱ)和115 d (采收期Ⅲ) 3个时段进行采收,采后果实在常温(25±1℃) 和相对湿度85%条件下贮藏,贮藏期间测定番石榴果实商品率、失重率、呼吸强度、相对电导率、色调角、硬度、可溶性固形物、可滴定酸、维生素C和总糖含量变化。结果表明,‘红心’番石榴果实采后软化迅速,颜色由绿转黄较快;随着采后贮藏时间的延长,番石榴果实的商品率、硬度、色调角、可滴定酸、维生素C和总糖的含量降低,而果实失重率、细胞膜相对透性增加;采收期Ⅰ较采收期Ⅱ、Ⅲ的耐贮性强。因此,对于‘红心’番石榴果实,考虑贮运期长,适宜在采收期Ⅰ采收;其他两个采收期可在产地销售。     

套袋对翠冠梨果实货架寿命及生理生化变化的影响

以翠冠梨为试材,研究了套袋对其果实货架寿命及生理生化变化的影响,试验结果表明,套袋能提高果实硬度、Vc含量及SOD活性,抑制细胞膜透性、MDA含量、呼吸速率及乙烯释放的迅速增加,从而有利于延缓果实衰老软化,且双层袋效果更好。     

Sources of variation in firmness and ester content of ''Cox'' apples stored in 2% oxygen

The contribution of various factors to variation in the quality of 'Cox' apples after storage in 2% oxygen at 3.3°C was investigated. Within one season variation in the firmness of fruits from different orchards could be largely accounted for by correlations with firmness at harvest and the position of the fruit on the climacteric at the time of harvest. However, different relationships were found between these variables in different seasons. The butyl and hexyl acetate contents of fruit were influenced by season and source of fruit, but little affected by maturity at harvest. Ester content was inversely correlated with fruit firmness after storage. Other factors which were expected to influence the ripening of fruit during storage were found to be unrelated to firmness and ester content. These included the respiration rate of fruit during storage, the resistance of the fruit to gaseous diffusion and its specific gravity. Carbon dioxide production was nearly constant at about 2.3 ml kg^-1h^-1 across seasons, sources and harvest dates. Specific gravity seemed to be particularly affected by season, whereas diffusive resistance decreased with maturity.     

成串采收对番茄果实采后乙烯合成及贮藏品质的影响

为研究成串采收对番茄果实采后乙烯合成及贮藏品质的影响,对广西田阳县两个栽培区两种嫁接砧木的串收番茄的采后生理指标进行测定,探讨了该采收方式对番茄果实采后保鲜的作用机制。结果表明:整个贮藏期,不同栽培区不同嫁接砧木的番茄成串采收的果实,乙烯生成量明显低于对照的常规单果采收。其中,砧木1号Ⅰ区的串收番茄的乙烯生成量,采后5 d即下降至最低点(0.35 nL·g~(-1)·h~(-1)),显著低于其对照(1.36 nL·g~(-1)·h~(-1)),其他栽培区和砧木组合的串收番茄,在采后15 d乙烯生成量达到最低值。串收番茄的类胡萝卜素、番茄红素和抗坏血酸等果实内天然抗氧化物质的含量,在贮藏前期快速升高,且峰值显著高于对照。此外,成串采收处理还一定程度抑制了果实后熟阶段可溶性糖的积累和可滴定酸的分解。因此,番茄成串采收处理,可能通过抑制果实采后乙烯的合成,同时提高类胡萝卜素、番茄红素和抗坏血酸的水平,并且推迟糖和酸等营养物质的后熟变化进程,实现其延长果实货架期,提高商品品质的作用。     

The combined effect of 1‐methylcyclopropene and citral suppressed postharvest grey mould of tomato fruit by inhibiting the growth of Botrytis cinerea

1‐Methylcyclopropene (1‐MCP, 1 μl/L) and 1 × minimum fungicidal concentration (MFC) citral alone and in combination were used to treat on postharvest tomato fruits to investigate their influence on disease incidence and postharvest quality during fruit storage, which were stored at 90%–95% relative humidity and 25 ± 2°C. Weight loss, pH, hue angle (Hue^°), total soluble solid (TSS), ascorbic acid content, firmness and antioxidant enzyme activities were evaluated after each storage period. 1 μl/L 1‐MCP or 1 × MFC citral reduced weight loss, retarded peel colour changes and retained postharvest fruit quality. 1 μl/L 1‐MCP + 1 × MFC citral could better maintain firmness and ascorbic acid content and increase antioxidant enzyme activities, compared to other treatments. Disease incidence of tomato fruit was significantly decreased, and spore germination and mycelia growth of Botrytis cinerea were suppressed by the combined treatment with 1 μl/L 1‐MCP and 1 × MFC citral. These results indicate that the combined treatment could effectively delay postharvest tomato fruits senescence and inhibit postharvest pathogens in vitro.     

短波紫外线照射对‘金都’火龙果采后保鲜的影响

以‘金都’火龙果(Hylocereus polyrhizus ‘Jindu’)果实为试材,采用波长254 nm紫外杀菌灯为辐射源,给予不同剂量短波紫外线(Ultraviolet-C,UV-C)照射处理,探讨低剂量UV-C对火龙果采后保鲜的影响及作用机理。结果表明,不同剂量UV-C照射处理能有效抑制‘金都’火龙果果实腐烂和电导率上升,降低果实TSS含量,其中1.0 kJ·m–2紫外线辐照效果最好。1.0 kJ·m–2 UV-C处理能极显著提高贮藏期火龙果的SOD和CAT活性,显著提高贮藏早中期的几丁质酶活性和PPO活性,β-1,3葡聚糖酶活性在贮藏后期也显著高于对照,但降低了火龙果贮藏中期(第6天)的POD活性。此外,1.0 kJ·m–2 UV-C处理显著提高火龙果贮藏期H2O2含量(除第6天外),对果实的失水率无影响。采后火龙果应用适当剂量UV-C照射可提高抗病性,延长贮藏保鲜期。     

温度对采后石榴果实品质和某些生理指标的影响

研究不同温度对采后石榴品种‘净皮甜’果实品质和某些生理指标影响的结果表明：在5℃条件下贮藏的石榴,其果实中可溶性固形物含量、总糖含量和可滴定酸含量可以得到保持,果皮的相对电导率和褐变指数升高速率减慢,果实的呼吸速率和腐烂率下降,抗坏血酸氧化酶（AAO）和多酚氧化酶（PPO）活性受到抑制,过氧化物酶（POD）和过氧化氢酶（CAT）活性保持相对较高水平。贮藏120d的果实品质良好,保鲜效果也较好。