精氨酸处理对采后冬枣黑斑病的抗病作用

为研究精氨酸（Arginine,Arg）处理对采后冬枣果实抗病性的影响,用不同浓度的Arg溶液（0、20、200、1000 μmol/L）浸泡枣果实,再对处理后的枣果实进行互隔交链孢（Alternaria alternata）接种,测定贮藏期间病斑直径、抗病相关酶的活性以及黄酮、多酚、木质素的含量。结果表明,Arg处理可以显著减缓冬枣接种A.alternata后病斑直径的扩展,进一步研究表明Arg处理能诱导其苯丙氨酸解氨酶（phenylalamineammonialyase,PAL）、过氧化物酶（peroxidase,POD）、β-1,3-葡聚糖酶（β-1,3-glucanase,GLU）、几丁质酶（chitinase,CHI）活性的上升,其中200 μmol/L Arg处理的抗病相关酶活性最高。同时,Arg处理能提高枣果实中黄酮、多酚和木质素的含量,且200 μmol/L Arg处理组的黄酮、多酚和木质素含量最高。由此表明,Arg处理通过提高抗病相关蛋白酶（PAL、POD、GLU、CHI）的活性以及黄酮、多酚、木质素的含量来增强采后冬枣果实的抗病能力,有望成为一种新的防腐保鲜剂应用于冬枣果实的防腐保鲜。     

采后亚硒酸钠处理对杏果黑斑病的控制及贮藏品质的影响

通过离体和体内实验研究亚硒酸钠对杏果黑斑病菌互隔交链孢（Alternaria alternata）的抑制作用及黑斑病的控制效果和贮藏品质的影响。结果表明,亚硒酸钠处理能显著抑制A. alternata菌落的生长和孢子萌发,且存在质量浓度效应,40 mg/L的亚硒酸钠能显著抑制A. alternata菌落的生长,其菌落直径较对照降低了30.8%,同时亚硒酸钠还能使A. alternata菌丝发生凹陷、扭曲等形态结构的改变;体内实验表明,采后亚硒酸钠处理能有效抑制损伤接种A. alternata的杏果黑斑病的扩展,其中20 mg/L亚硒酸钠的控制效果最佳,其病斑直径较对照减小了11%;采后亚硒酸钠处理还能够明显减少杏果乙烯的释放和呼吸强度的升高,延缓质量损失率和硬度的降低。可见硒在果蔬采后防腐保鲜中具有潜在的应用前景。     

壳聚糖复合硅酸钠对冬枣采后苯丙烷代谢及病程相关蛋白的影响

研究了壳聚糖复合硅酸钠浸泡处理对A. alternata挑战接种果实的苯丙烷代谢与防御相关酶的影响。以冬枣为材料,分别用1%的壳聚糖(chitosan,CTS)复合不同浓度(10、40、160 mmol/L)的Na₂SiO₃水溶液浸泡冬枣5 min,以蒸馏水作为对照。室温下贮藏并定期测定其病斑直径、类黄酮、多酚、木质素及相关酶的活性。实验结果显示:在贮藏20 d后,1% CTS+40 mmol/L Na₂SiO₃处理病斑直径为1% CTS处理组病斑直径的57.33%。1% CTS+40 mmol/L Na₂SiO₃处理激活了苯丙氨酸解氨酶(Phenylalane Ammonlalyase,PAL)、肉桂酸4-羧化酶(Cinnamate 4 Hydroxylase,C4H)、4-香豆酰-辅酶A连接酶(4coumarate Coenzyme A Ligase,4CL)、过氧化物酶(Peroxidase,POD)的活性,使得总酚、类黄酮、木质素含量增加。同时,病程相关蛋白几丁质酶(Chitinase,CHT)、β-1,3葡聚糖酶(β-1,3-giucanase,GLU)活性增强。实验结果表明,CTS+Na₂SiO₃处理可以通过诱导果实苯丙烷代谢和病程相关蛋白活性增强采后枣果实抗病性。     

吡啶-2,6-二羧酸处理对梨果采后黑斑病控制作用及其抑菌机理

由互隔交链孢（Alternaria alternata）引起的黑斑病是梨果主要采后病害之一,会导致严重的经济损失。本实验以梨果黑斑病菌A. alternata为研究对象,通过体内外实验研究了枯草芽孢杆菌（Bacillus subtilis）代谢产物吡啶-2,6-二羧酸（pyridine-2,6-dipicolinic acid,DPA）对A. alternata生长的抑制和对梨果黑斑病的控制作用,并进一步探讨了其抑菌作用的机理。结果表明：DPA能显著抑制A. alternata的菌落生长、孢子萌发以及芽管伸长,其中2.0 mmol/L DPA处理后培养9 d时A. alternata菌落直径仅为对照组的51.76%,4.0 mmol/L处理可完全抑制A. alternata的生长。DPA处理对梨果黑斑病的扩展有明显的控制作用,贮存至第11天时,20.0 mmol/L DPA处理组早酥梨病斑直径仅为对照组的55.17%。进一步研究表明,DPA处理提高了A. alternata细胞膜的通透性,菌丝电导率、蛋白质和核酸渗漏量显著增加,同时DPA处理降低了细胞膜组分麦角甾醇质量浓度,提高了A. alternata丙二醛浓度。结论：DPA可通过延缓A. alternata生长、提高膜通透性、破坏细胞膜的完整性和促使膜脂氧化而发挥抑菌作用。     

1-甲基环丙烯处理对台湾青枣果实采后病害的抑制

为研究1-甲基环丙烯(1-MCP)处理对果实病害与抗病性诱导的影响,采用1.8μL/L 1-MCP处理“中青”台湾青枣果实12 h后在(15±1)℃下贮藏。定期观察果实腐烂和病害情况,测定总酚、木质素含量及抗病相关酶[β-1,3-葡聚糖酶(GLU)、几丁质酶(CHI)、苯丙氨酸解氨酶(PAL)]活性的变化。结果表明:1-MCP处理在贮藏前期诱导了台湾青枣果实病程相关蛋白(GLU和CHI)活性上升,两者协同作用直接抵抗病原体;同时,1-MCP处理还诱导了台湾青枣果实PAL活性上升,增加了细胞内木质素和总酚含量的积累,有利于形成间接抵抗病原体的结构性障碍;1-MCP处理的果实腐烂指数和病害指数显著低于对照,台湾青枣果实采后1-MCP处理减轻了果实贮藏期间病害的发生,减少采后腐烂损失。这些结果说明1-MCP抑制台湾青枣果实采后病害与其诱导抗病相关酶活性的升高有关。     

外源褪黑素调控活性氧代谢诱导采后杏果实对黑斑病的抗性

以新疆‘赛买提’杏为试验材料,探究外源褪黑素对采后杏果实黑斑病抑制效果及活性氧代谢的影响。将杏果实分别置于50、100、200μmol/L褪黑素溶液进行减压(0.05 MPa)处理2 min后,常压状态下浸泡8 min,以蒸馏水同样处理作为对照,自然晾干后的杏果实转入温度(0±1)℃,相对湿度90%～95%条件下放置48 h后,损伤接种互隔交链孢(Alternaria alternata)于相同条件下贮藏,定期测定杏果实接种发病率和病斑直径及超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)、过氧化物酶(Peroxidase,POD)酶活力,及超氧阴离子(Superoxide anion,O₂^-·)产生速率、细胞膜渗透率、过氧化氢(Hydrogen peroxide,H₂O₂)和丙二醛(Malondialdehyde,MDA)含量。结果表明：与对照组相比,不同浓度外源褪黑素处理显著延缓了杏果实发病率的上升(P<0.05),抑制了杏果实病斑...     

Effects of 1-methylcyclopropene(1-MCP) on ripening and resistance of jujube (Zizyphus jujuba cv. Huping) fruit against postharvest disease

The effects of 1-methylcyclopropene (1-MCP) on senescence and induction of resistance against postharvest decay in jujube (Zizyphus jujuba cv. Huping) fruit were investigated in this study. The results indicated that, compared to control, 1-MCP at 1 μL L^?l depressed ethylene production by 28% and respiration rate by 30% at 24 h after treatment, resulting in effective delay in fruit senescence. 1-MCP treatment was beneficial for maintaining quality of jujube fruit stored both at 25 and 0 °C, retarding decline of firmness, vitamin C, titratable acidity (TA) and soluble solids content (SSC) which are important parameters for fruit quality evaluation during the storage periods. Moreover, 1-MCP effectively limited the development of lesion diameter of blue mold rot and significantly reduced the incidence of natural decay. The activities of phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), catalase (CAT) and superoxide dismutase (SOD) were significantly induced after 1-MCP treatment. These findings indicate that the induced resistance in jujube fruit by 1-MCP is related with the increase of enzymes involved in scavenging of reactive oxygen species and enzymes associated with phenolics metabolism which produces highly toxic products against pathogen invasion. Our results suggest that 1-MCP has potential effect on maintaining the quality and extending postharvest life of jujube fruit.     

Combined treatments of chitosan and sodium silicate to inhibit Alternaria alternata pathogens of postharvest winter jujube

Alternaria alternata is a pathogenic fungus that infects jujube fruit and leads to serious economic losses. In this paper, the antifungal activity of chitosan combined with sodium silicate against A. alternata in vitro and in vivo was investigated, and the possible antimicrobial mechanisms were explored. Results showed that the spore germination and colony expansion of A. alternata were significantly inhibited by chitosan. Chitosan treatment induced the leakages of intercellular electrolytes, nucleic acids, and soluble protein of A. alternata. Meanwhile, chitosan damaged the cell morphology and membrane integrity of A. alternata. The combination of chitosan and sodium silicate was more effective than chitosan alone. In addition, the effect of chitosan and sodium silicate could significantly decrease natural rot rate and delay lesion expansion of winter jujube. Collectively, chitosan combined with sodium silicate had the potential to control postharvest diseases of fruit caused by A. alternata.     

L-谷氨酸对樱桃番茄果实病程相关蛋白的影响

为研究L-谷氨酸(谷氨酸)对果实采后病害的抗性机制,以樱桃番茄为对象,将其浸泡于100 mg/L谷氨酸溶液10 min,经不同诱导时间(0、12、24、36 h)处理后接种Alternaria alternata,定期测定果实的发病率,同时研究谷氨酸对果实病程相关蛋白(pathogenesis-related proteins,PRs)及其编码基因的影响。在体外条件下,观察谷氨酸对病原菌生长状态的影响。结果表明:谷氨酸诱导时间在24 h及以上时,番茄发病率显著下降;体外试验中,谷氨酸对病原菌的孢子萌发率和生长无明显影响;谷氨酸可迅速提高果实β-1,3-葡聚糖酶、几丁质酶(chitinases,CHI)和过氧化物酶(peroxidase,POD)的活力,且诱导LePR1、LePR5、LeCHI3、LeCHI9和LePOD上调表达。综上,谷氨酸对Alternaria alternata的作用机制可能与其诱导了果实体内的病程相关蛋白有关。     

Biocontrol of Alternaria alternata on cherry tomato fruit by use of marine yeast Rhodosporidium paludigenum Fell & Tallman

The basidiomycetous yeast Rhodosporidium paludigenum Fell & Tallman isolated from the south of East China Sea was evaluated for its activity in reducing postharvest decay of cherry tomatoes caused by Alternaria alternata in vitro and in vivo tests. The results showed that washed cell suspension of R. paludigenum provided better control of A. alternata than any other treatment, while the autoclaved cell culture failed to provide protection against the pathogen. The concentration of antagonist had significant effect on biocontrol effectiveness in vivo: when the concentration of the washed yeast cell suspension was used at 1 x 10(9)cells/ml, the percentage rate of black rot of cherry tomato fruit was only 37%, which was remarkably lower than that treated with water (the control) after 5days of incubation at 25 degrees C. Furthermore, a great biocontrol efficacy of R. paludigenum was observed when it was applied prior to inoculation with A. alternata: the longer the incubation time of R. paludigenum, the lower disease incidence would be. However, there was little efficacy when R. paludigenum was applied after A. alternata inoculation. In addition, on the wounds of cherry tomato, it was observed that R. paludigenum grew rapidly increasing 50-fold during the first 12h at 25 degrees C. To the best of our knowledge, this is a first report concerning that the marine yeast R. paludigenum could be used as a biocontrol agent of postharvest fungal disease.     

香芹酚处理对枸杞鲜果采后黑霉病的控制

为探究香芹酚处理对宁夏枸杞鲜果采后黑霉病的控制,在离体条件下研究了香芹酚对宁夏枸杞鲜果采后黑霉病菌(Alternaria alternata)生长、菌落形态及其超微结构的影响,并在活体条件下研究了其对枸杞黑霉病的控制效果以及对果实过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)活性的影响。离体试验结果表明:香芹酚处理能显著抑制A. alternata的孢子萌发和菌丝生长,其抑制效果存在浓度依赖效应;与对照相比,浓度为8 μL/L香芹酚对菌丝生长和孢子萌发的抑制率分别达到80.81%和57.17%;扫描电镜观察发现香芹酚处理的A. alternata菌丝量少,表面粗糙,粗细不均匀,部分出现塌陷,孢子细胞受到不同程度的破坏。进一步体内试验结果表明:香芹酚处理枸杞果实能抑制损伤接种黑霉病的发病率和病斑扩展速度,并且处理还能提高果实的POD和PAL活性。由此可见,香芹酚可以通过直接治愈和间接诱导抗性来控制枸杞鲜果采后黑霉病,在采后病害控制中具有潜在的应用前景。     

Effects of 1‐methylcyclopropene and gibberellic acid on ripening of Chinese jujube (Zizyphus jujuba M) in relation to quality

Overripening of Chinese jujube (Zizyphus jujuba M) fruit at the postharvest stage usually results in a dramatic decline in quality. The role of 1‐methylcyclopropene (1‐MCP) and gibberellic acid (GA) in fruit ripening of Chinese jujube during storage in relation to quality was investigated. Fruit ripening of jujube was significantly enhanced by ethylene, whereas rates of respiration and ethylene production of the fruit were reduced by 1‐MCP. Treatment with 1‐MCP or GA delayed the decreases in firmness and vitamin C and reduced the level of ethanol. Furthermore, the effectiveness of 1‐MCP was improved by replicate treatments during storage at 20 or 2 °C. In addition, treatment with GA + 1‐MCP resulted in additive beneficial effects on ripening inhibition of the fruit. Copyright © 2003 Society of Chemical Industry     

Effect of hexanal vapour on longan fruit decay,quality and phenolic metabolism during cold storage

The effects of postharvest treatment with hexanal vapour on longan fruit decay, quality, hexanal residue, phenolic compound content, and polyphenoloxidase (PPO) and peroxidase (POD) activities were studied during storage at 5 °C for 30 days. Hexanal exposure for 2 h at 900 μL L^?1 before cold storage reduced the percentage of fruit with decay and was deemed the optimum treatment. Hexanal exposure resulted in a pericarp that was more reddish brown and less intense in colour. Hexanal residue in the pericarp and aril of fumigated fruit was several fold higher than that of nonfumigated fruit, although levels were low at the end of cold storage. Electrolyte leakage of pericarp increased during 5 °C storage and was further increased by hexanal exposure. Hexanal reduced pericarp phenolic content, and increased PPO and POD activities. Overall, use of hexanal vapour reduced postharvest disease of longan fruit but increased the likelihood of pericarp browning.     

外源磷酸钠对枣果实活性氧和苯丙烷代谢关键酶活性及酚类物质积累的影响

以三星枣果实为材料,采后用0.5 mg/mL磷酸钠溶液浸泡处理10 min,研究其对室温贮藏期间枣果实活性氧和苯丙烷代谢关键酶活性和酚类物质积累的影响。结果表明,磷酸钠处理提高了整个贮藏期间枣果实过氧化氢含量,并且在贮藏第4 d和第10 d出现高峰,同时显著提高了贮藏第4~12 d和4~8 d果实抗坏血酸过氧化物酶和谷胱甘肽还原酶活性（P<0.05）。此外,磷酸钠显著提高了贮藏中后期果实苯丙氨酸解氨酶、4-香豆酰CoA连接酶和过氧化物酶活性,分别在贮藏第6、8和8 d出现高峰,是对照果实的1.18、1.16和1.40倍（P<0.05）。这些酶活性的升高显著促进了贮藏第6~12 d果实中总酚和类黄酮的积累,并且分别在贮藏第8 d和10 d达到高峰,是对照果实的1.38和1.29倍（P<0.05）。由此表明,采后外源磷酸钠处理能够激活枣果实活性氧清除酶的活性,增强苯丙烷代谢关键酶活性和酚类物质的积累,从而保持果实的抗病能力。     

Synergistic effects of combining biocontrol agents with silicon against postharvest diseases of jujube fruit

The synergistic effects of biocontrol yeasts Cryptococcus laurentii and Rhodotorula glutinis combined with silicon (Si) against Alternaria alternata and Penicillium expansum molds were investigated in jujube fruit (Chinese date, Zizyphus jujuba) stored at 20 and 0 degrees C, respectively. Combinations of C. laurentii and R. glutinis at 5 x 10(7) cells/ml with 2% Si was most effective in controlling the diseases caused by A. alternata and P. expansum on jujube fruit stored at 20 degrees C. When fruits were stored at 0 degrees C, combining C. laurentii and R. glutinis with Si was as effective against P. expansum as was Si or the yeasts applied alone and was more effective in controlling A. alternata. Si may have a fungistatic effect by directly inhibiting pathogen growth, but it did not greatly influence the growth of the antagonists.     

采后一氧化氮处理对油桃抗软腐病的诱导

以油桃为实验对象,研究了采后NO供体硝普钠(SNP)处理对低温贮藏期间油桃根霉软腐病的控制效果及其机理。研究结果表明硝普钠处理能显著地抑制损伤接种Rhizopus stolonifer的油桃果实软腐病的扩展,其中较低浓度5mmol/L的硝普钠处理效果最好,其病斑直径仅为对照的75.83%。进一步研究表明SNP浸泡处理能显著地提高低温贮藏期间油桃果实组织苯丙氨酸解氨酶(PAL)和过氧化物酶(POD)的活性,且在贮藏后期对组织过氧化氢酶(CAT)和超氧化物歧化酶(SOD)酶活性具有抑制作用,然而对多酚氧化酶(PPO)的活性没有明显的诱导作用。可见一氧化氮是通过改变油桃抗性相关酶的活性来增强果实的抗病性。     

ε-聚赖氨酸对樱桃采后病原菌橘青霉和链格孢菌的抑菌作用研究

目的 探究ε-聚赖氨酸(ε-polylysine,ε-PL)对樱桃果实采后病原菌橘青霉(Penicillium citrinum)和链格孢菌(Alternaria alternata)的抑菌作用和抑菌机制。方法 本研究测定100、200、400、800 mg/Lε-PL处理对2种病原菌菌丝生长、孢子萌发、细胞膜透性的影响;采用扫描电子显微镜(scanningelectron microscope,SEM)观察ε-PL处理对病原菌孢子的形态的影响;并在樱桃果实上接种2种病原菌,观测ε-PL处理在果体上的抑菌作用。结果 ε-PL对P.citrinum和A.alternata菌落直径扩展的抑制效果随着处理浓度的增加而提高,大于200 mg/L的ε-PL显著抑制孢子萌发;经ε-PL处理后2种病原菌的电导率、OD_{280 nm}、OD_260nm均显著升高(P<0.05),细胞膜通透性增加,蛋白质和核酸等内容物渗漏,细胞膜完整性遭到破坏;经SEM观察发现,ε-PL处理后P. citrinum和A. alternata孢子变形、凹陷,失去正常的细胞形态;...     

Combination of UV‐C Treatment and Metschnikowia pulcherrimas for Controlling Alternaria Rot in Postharvest Winter Jujube Fruit

The potential of using antagonistic yeast Metschnikowia pulcherrimas alone or in combination with ultraviolet‐C (UV‐C) treatment for controlling Alternaria rot of winter jujube, and its effects on postharvest quality of fruit was investigated. The results showed that spore germination of Alternaria alternata was significantly inhibited by each of the 3 doses (1, 5, and 10 kJ m^?2) in vitro. In vivo, UV‐C treatment (5 kJ m^?2) or antagonist yeast was capable of reducing the percentage of infected wounds and lesion diameter in artificially inoculated jujube fruits, however, in fruit treated with combination of UV‐C treatment and M. pulcherrima, the percentage of infected wounds and lesion diameter was only 16.0% and 0.60 cm, respectively. The decay incidence on winter jujube fruits treated with the combination of UV‐C treatment and M. pulcherrima was 23% after storage at 0 ± 1 °C for 45 d followed by 22 °C for 7 d. None of the treatments impaired quality parameters of jujube fruit. Thus, the combination of UV‐C radiation and M. pulcherrima could be an alternative to synthetic fungicides for controlling postharvest Alternaria rot of winter jujube.     

热水处理对近冰温贮藏鲜枣品质提高与膜脂代谢的相关性分析

以采后临泽小枣（Zizyphus jujuba Mill. cv. Linzexiaozao）为实验材料,探讨热水处理对近冰温贮藏鲜枣果实耐冷性与膜脂脂肪酸组分变化的影响。采后果实用60 ℃热水浸泡1 min,自然干燥后,装入带有若干小孔(孔径为2 mm)的聚乙烯塑料饭盒,置于(?1.5~?2)℃的冷库中贮藏,定期测定果实冷害指数、细胞膜透性、丙二醛(MDA)、脂氧合酶(LOX)活性及膜脂脂肪酸组分变化。与对照相比,贮藏50 d时,热水处理果实的冷害指数、相对电导率、MDA和LOX活性分别降低了7.56、17.93%、17.93 μmol/g·FW和15.84 U/g·FW,不饱和脂肪酸油酸(C_18:1)、亚油酸(C_18:2)和亚麻酸(C_18:3)的相对含量及膜脂脂肪酸不饱和指数(IUFA)、脂肪酸不饱和度(UFA/FA)分别增加了11.10%、9.13%、8.60%和55.17、0.65,饱和脂肪酸肉豆蔻酸(C_14:0)、棕榈酸(C_16:0)、硬脂酸(C_18:0)和花生酸(C_20:0)的相对含量也分别降低了54.10%、18.66%、17.93%和3.37%,且差异显著(P<0.05)。尤其是对照LOX活性与亚麻酸(C_18:3)的相对百分含量变化有极显著(P<0.01)的负相关性(r=?0.931)。结果表明,鲜枣在近冰温冷藏下发生冷害的程度与膜脂中亚麻酸（C_18:3）的相对含量变化存在相关性。热水处理抑制了鲜枣膜脂脂肪酸不饱和指数(IUFA)和脂肪酸不饱和度(UFA/FA)的下降,诱导膜脂中不饱和脂肪酸的降解速率减缓,从而维持较高的膜脂稳定性,使采后鲜枣近冰温贮藏的耐冷性增强。     

对羟基苯甲酸酯类对杏果采后病害的控制

通过离体和体内实验研究对羟基苯甲酸酯类处理对杏果采后黑斑病和软腐病的控制。离体实验结果表明,对羟基苯甲酸酯类对互隔交链孢（Alternaria alternata）和匍枝根霉（Rhizopus stolonifer）菌丝生长具有一定的抑制作用,其中对羟基苯甲酸乙酯和对羟基苯甲酸丁酯抑制效果较好,并随着处理剂量的增加抑制效果显著增加,100 μL/L对羟基苯甲酸丁酯对A. alternata和R. stolonifer菌落生长的抑制效果佳,其对菌落直径的抑菌率分别达到了23.70%和62.48%,同时发现对羟基苯甲酸酯类对R. stolonifer的抑制作用较强。体内实验结果表明,对羟基苯甲酸酯类能有效地控制损伤接种的杏果黑斑病和软腐病的扩展,对软腐病的控制效果较好。其中240 μL/L的对羟基苯甲酸乙酯对杏果黑斑病和软腐病的抑制效果最佳。进一步通过正交试验确定了对羟基苯甲酸酯类与热水复合对杏果的最佳防腐处理条件为32 μL/L的对羟基苯甲酸丙酯,在50 ℃热水中浸泡7 min,该复合对采后杏果的病害控制效果最佳,验证实验表明,其对黑斑病和软腐病的抑菌率分别达到了32.22%和51.84%。