套袋处理提高‘妃子笑’荔枝果实耐贮性

  对‘妃子笑’荔枝果实进行采前无纺布套袋处理, 采后置于常温、无任何药剂处理和纸皮包装的条件下, 其耐贮性明显优于无套袋对照, 坏果率较低、果皮失水较慢、pH值相对较低。套袋果实果皮的蛋白质含量增多, 过氧化物酶( POD) 活性降低, 但多酚氧化酶( PPO) 活性无明显不同; 果皮蜡质层较对照厚, 海绵状组织有大型薄壁细胞分布。套袋后的变化有利于增强果皮的保水能力和延迟衰老, 从而推迟失水褐变出现的时间, 延长果实的贮藏寿命。     

外援抗氧化剂对高温胁迫下红地球葡萄果实日灼的影响

以红地球葡萄为试材,通过施用抗坏血酸(AsA)、苯甲酸钠(SBN)和氯化钙(CaCl2),研究不同种类外源抗氧化剂对高温胁迫下果皮组织对丙二醛(MAD)含量、相对电导度(REC)、过氧化氢酶(CAT)和抗坏血酸-过氧化物酶(APX)活性的影响,比较几种抗氧化剂对提高果实抗氧化能力的效果。结果表明:在高温胁迫下,以施用0.03 mol/L抗坏血酸0、.02 mol/L苯甲酸钠和0.10%氯化钙后,能显著和极显著地降低膜脂过氧化产物MDA的含量,保持膜结构及功能相对稳定性,提高果实CAT和APX酶活性,从而提高了果实抗日灼的能力。     

1-甲基环丙烯对高温下香蕉果实后熟的影响

以香蕉果实为试材,研究了1-甲基环丙烯(1-MCP)对高温逆境下香蕉果实后熟生理的影响。结果表明:35℃高温下贮藏的香蕉果实出现了明显的青皮熟现象,而0.5μL/L的1-MCP处理24h后可显著抑制高温下贮藏果实硬度的降低,延缓果皮细胞膜透性的升高,同时有效地延迟了果肉中淀粉酶活性升高、淀粉含量下降及可溶性糖含量上升。1-MCP处理果实于35℃下贮藏9d后移入20℃环境,进一步延缓了这些后熟生理变化。1-MCP和高温均抑制了果皮叶绿素含量下降,因此1-MCP处理减轻了香蕉热害的程度,延长了果实在高温下的贮藏寿命。     

水杨酸与高温锻炼对高温胁迫下葡萄叶肉细胞质膜ATPase活性的影响

采用水性两相分配法对经水杨酸(SA)和高温锻炼处理过的葡萄幼苗叶肉细胞中ATPase进行了分离和测定.结果表明:高温下,细胞质膜ATPase活性随着胁迫程度的加深均呈下降趋势,经SA和高温锻炼预处理后再经高温胁迫,发现质膜ATPase的活性低于正常条件下的水平(CK1),但明显高于未经处理直接进行高温胁迫后ATPase活性水平,即高温锻炼和SA预处理的质膜酶活仍保持了较高的活性,并且后一种处理效果更明显.说明质膜上ATPase活性的变化对高温胁迫作出了一定的响应,SA和高温锻炼对提高葡萄幼苗叶片的抗热性与二者可以维持细胞质膜上ATPase活性的稳定有关.     

冬枣裂果原因及综合防治措施

正1症状1.1梗洼处裂果多在近果蒂部位,即梗洼周围发生环状或放射状裂口,果肉稍外露,果实开裂点一般在果柄处。雨后果实梗洼处易存水,晴天后在强光照射下,水温上升,梗洼处的果皮受高温影响,部分组织受损,果皮迅速老化,遇雨后从此处开始裂果。1.2日灼、机械伤、病虫害等处裂果果实受到伤害后,表皮过早停止生长的部位成为开裂点,后扩散到其它部位。尤其在日灼处最为突出。1.3缺素症裂果硼元素缺乏时,果实尾尖处出现开     

香蕉果实贮藏冷害与PAL活性及可溶性蛋白的关系

研究了200μmol/L脱落酸(ABA)和5mmol/L腐胺(Put)处理对贮藏于8℃下条件的香蕉果实耐冷性的影响及其与PAL活性及可溶性蛋白的关系。结果表明:与对照果实相比较,ABA和Put两种处理都不同程度地减轻香蕉果实贮于8℃条件下的冷害。具体表现在,两种处理均延缓了果皮颜色变暗与细胞膜透性的升高,提高了果皮可溶性蛋白含量,维持果实果皮较高的PAL活性。本文还讨论了香蕉果实耐冷性与果皮PAL活性的关系。     

1 - 甲基环丙烯处理荔枝果实减轻其贮藏中冷害的研究

 研究了‘桂味’荔枝果实采后1 - 甲基环丙烯( 1-MCP) 处理对其0℃贮藏过程中冷害发生和相关生理生化指标的影响。结果表明: 12MCP处理有效推迟了冷害主要症状即果皮褐变的出现, 延缓了果皮花色素苷含量的下降, 抑制了果实的乙烯释放速率, 但对呼吸速率的影响不明显。进一步的研究表明, 1-MCP处理提高了果实冷藏前期超氧化物歧化酶( SOD) 和过氧化氢酶(CAT) 活性, 降低了果皮多酚氧化酶( PPO) 活性, 抑制了后期过氧化物酶( POD) 和抗坏血酸过氧化物酶(AsA-POD) 活性的提高。     

高温下光照变化对鸭梨果实抗氧化物质变化规律的影响

以鸭梨果实为试料,采用高温(45℃)下光照变化以及田间不同驯化处理等方法,研究了其对鸭梨果实活性氧、抗氧化酶活性和抗氧化物质含量变化的影响,明确了鸭梨果实对温度光照互作的响应。结果表明:高温(45℃)下增加光照显著提高了果实内H2O2含量、DHA含量、膜相对透性和POD活性,抑制了SOD、APX、GR、MDAR活性和AsA含量的增加;未经驯化(摘叶和转位)处理果实的H2O2含量和膜相对透性显著高于树冠外围自然暴露果实,抗氧化酶活性无显著性变化。这表明高温下增加光照加重了对果实的伤害,经过驯化处理的果实的抗氧化性显著提高。     

红肉脐橙果实中抗氧化物质含量及其抗氧化活性变化

以红肉脐橙果实为材料,分析了果实稳果后果皮和果肉活性成分含量的变化及其与体外抗氧化能力的关系.结果表明,随着果实成熟,果肉中谷胱甘肽、总酚、类黄酮含量以及体外抗氧化活性先上升后下降;而果皮中抗坏血酸、谷胱甘肽、总酚、类黄酮含量以及体外抗氧化活性均在果实发育初期出现最大值,且在果实发育过程中不断降低.相关性分析表明,所有...     

持续强降雨后高温强光对猕猴桃叶片光合和根系代谢的影响

【目的】探讨上海地区夏季持续强降雨后的高温晴朗天气对猕猴桃树体生理的影响。【方法】以美味猕猴桃‘徐香’为试材,人工模拟强降雨和高温强光环境,将猕猴桃植株在不同时长强降雨下处理后转移到高温强光下生长,测定土壤含水量及猕猴桃植株叶片和根系的各项生理指标。【结果】随强降雨时间延长,猕猴桃叶片受损程度增加,且受损程度与强降雨后的高温强光时长呈现显著正相关,持续强降雨3~5 d后在高温强光下3~4 d,猕猴桃叶片净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)明显下降,胞间CO2浓度(Ci)上升,根系活力降低,而相对电导率、丙二醛(MDA)含量、游离脯氨酸含量及抗氧化酶SOD、POD、CAT的活性显著升高。【结论】持续强降雨3~5 d后在高温强光下3~4 d会破坏猕猴桃根系的正常生理代谢,造成猕猴桃幼苗叶片萎蔫,最终导致植株死亡。     

Response of the phenylpropanoid pathway to Venturia inaequalis infection in maturing fruit of ‘Braeburn’ apple

Summary

This study investigated the activities of key enzymes in the phenylpropanoid pathway and the accumulation of phenolic products in apple peel in response to infection with Venturia inaequalis [(Cooke) G. Wint.]. We compared healthy apple peel with apple peel showing symptomatic scab lesions, and with peel tissue from 1 – 2 mm around the scab lesions in fruit 1 month before maturity [140 d after full bloom (DAFB)] and at physiological maturity (175 DAFB). Infection with V. inaequalis enhanced the synthesis of some phenolic compounds. Compared to healthy peel, scab lesion tissue had ≤ 3.1-times higher hydroxycinnamic acid content, ≤ 1.3-times higher dihydrochalcone content, and ≤ 3.9-times higher flavan-3-ol content. Scab lesions showed slightly higher phenylalanine ammonia-lyase, chalcone synthase, chalcone isomerase, flavonol synthase, and dihydroflavonol 4-reductase activities. The total amount of phenolics remained relatively stable between the two sampling dates, except for epicatechin and caffeic acid which decreased in amount toward fruit maturity, and levels of catechin which increased in more mature fruit. During fruit maturation, only chalcone synthase and chalcone isomerase activities decreased in all tissues examined. This study showed that the phenylpropanoid pathway in apple fruit peel changed significantly following infection with the apple scab pathogen.     

红富士苹果摘袋后着色进程与抗氧化能力的关系

为指导套袋红富士苹果根据天气适时摘袋,避免日烧,对套袋红富士苹果摘袋后着色进程与抗氧化能力的关系进行研究。结果表明,套袋红富士苹果在十月初摘袋后2d即开始有明显的花青苷积累和红色表现,清除自由基的能力也明显增强,但只有到摘袋后第3d花青苷含量大幅增加后,果实遇低温强光时才可能避免日烧。建议红富士苹果摘袋时要注意天气预报,避开3d内的霜冻。     

Influence of a pre-harvest reflective orchard mulching film on lipid peroxidation and anti-oxidant activity in apple fruit during post-harvest storage

Summary

Studies have shown that applying a reflective film to the floor of an orchard enhances fruit colouration. Here we assessed whether this practice also prolonged the post-harvest storage life of apple (Malus domestica Borkh cv. Fuji and Malus prunifolia [Willd.]) fruit. Strips of reflective mulching film (RMF) were placed beneath the apple trees and RMF-treated fruit were compared with those from untreated control (CK) trees. Enzymes involved in reducing lipid peroxidation such as superoxide dismutase (SOD) and catalase (CAT) are associated with delaying fruit senescence. Their activities, as well as malondialdehyde (MDA) concentrations, were quantified as indicators of physiological changes related to lipid peroxidation and membrane damage in the peel and flesh of RMF-treated or control apple fruit during 50 d of post-harvest storage at 4ºC. SOD activities increased in the peel and flesh from RMF-treated fruit during the first 40 d post-harvest, but declined significantly during the final 10 d of storage. RMF treatment resulted in increases in CAT activities of 5 – 14% and 16 – 29% in the peel and flesh of RMF-treated apples, respectively, compared with untreated CK fruit. Conversely, MDA concentrations were 7 – 23% and 14 – 30% lower in the peel and flesh, respectively, of RMF-treated fruit than in CK fruit over the 50 d storage period. Similarly, RMF treatment resulted in reductions of 7 – 20% and 3 – 10% in saturated fatty acid (SFA) concentrations in the peel and flesh, respectively, compared to CK fruit, while the corresponding polyunsaturated fatty acid (PUFA) concentrations increased by 2 – 10% and 3 – 7%. In conclusion, the use of RMF in apple orchards appears to be an effective technique to delay post-harvest senescence in apple fruit.     

MdMYB10对苹果果皮苯丙氨酸代谢的影响

MdMYB10对苹果果皮花青苷合成起重要作用,但对苯丙氨酸代谢途径中其他酚类物质合成是否起作用尚不清楚。从‘粉红女士’苹果（Malus ? domestica‘Pink Lady’）果皮中克隆了MdMYB10,分别构建其过表达载体pCAMBIA2301-MdMYB10和沉默载体pTRV2-MdMYB10,在套袋苹果果皮下注射农杆菌诱导MdMYB10过表达和沉默,分析MdMYB10对解袋后苹果果皮苯丙氨酸代谢的影响。结果表明,在过表达MdMYB10的果皮组织中,MdMYB10表达量上调了19.62倍,MdPAL、MdCHS、MdF3H、MdDFR、MdANS、MdUFGT、MdFLS、MdANR均有不同程度的上调,只有MdLAR无显著变化;沉默MdMYB10的果皮组织中,MdMYB10表达量降低了87%;MdCHS、MdF3H、MdDFR、MdANS和MdUFGT均有不同程度的下调,其中MdANS和MdUFGT下调最多,分别下调83%和82%。在过表达MdMYB10的果皮中,花青苷含量升高了3.05倍,槲皮素–3–O–半乳糖苷、表儿茶素、原花青素B2、绿原酸、对香豆酸含量均有不同程度升高,根皮苷含量无明显变化;在沉默MdMYB10的果皮中,花青苷含量降低了83%,槲皮素–3–O–半乳糖苷和表儿茶素含量分别降低58%和52%,原花青素B2、根皮苷含量无明显变化,而绿原酸含量升高了24%,对香豆酸含量升高了21%。可见,MdMYB10不仅调控苹果果皮中花青苷合成,同时还调控苯丙氨酸代谢中绿原酸、对香豆酸、槲皮素–3–O–半乳糖苷、表儿茶素和原花青素B2等物质的合成,但对根皮苷的形成作用不明显。     

微域环境及外源物质对苹果果实5'- 核苷酸酶活性的影响

 果实所处的微域环境对果皮组织中5'- 核苷酸酶活性有很大影响。无论套袋与否, 均以树冠西南方位果实的酶活性最高。由于套袋提高了微域环境温度, 果实5'- 核苷酸酶活性均显著高于不套袋处理。不同类型果袋所形成的微域环境不同, 对果实5'- 核苷酸酶活性影响的效应有异。在一定范围内, 缓慢持续升温或起伏升温都有利于果实5'- 核苷酸酶活性的提高, 但如果升温时间太短, 或温差变化太大,则不利于酶活性的提高。果实在35℃、40℃或48℃处理温度下, 高湿状态均有利于果实5'- 核苷酸酶活性的提高。4种外源活性氧处理均使果实5'- 核苷酸酶活性显著下降, 而外源CaCl₂处理果实酶活性比对照提高了55.39%。     

温度逆境锻炼对高温下黄瓜幼苗生理的影响

低温和高温两种不同的逆境锻炼均能提高黄瓜幼苗在高温条件下的游离态水杨酸（ＳＡ）、可溶性蛋白质含量,提高或保持膜保护酶的活性,减轻膜脂过氧化程度,从而增强幼苗对高温的抵抗能力。高温处理使未锻炼的黄瓜幼苗表观光合量子效率（ＡＱＥ）和光合效率（ＣＥ）明显下降,净光合速率（Ｐｎ）降低。温度逆境锻炼使气孔导度（Ｇｓ）、ＡＱＥ、ＣＥ降低较少,保持较高Ｐｎ。表明高温锻炼和低温锻炼在提高黄瓜幼苗抗性方面具有相似的作用,膜保护系统、可溶性蛋白质和游离态ＳＡ对黄瓜幼苗耐高温性具有重要的意义。     

套袋对苹果果实钙素吸收与分布的影响

以红富士苹果(Malus domestica Borkh.cv.Fuji)为试材,进行了套袋处理,以不套袋果实为对照,测定其果实的Ca含量,研究套袋对果实钙素吸收与分布的影响。结果表明,果实套袋后,在花后40～90d,整果钙吸收量高于对照果实;从花后120d开始,对照果实整果钙含量一直高于套袋果实。此外,苹果果实在整个生长发育过程中对Ca都有吸收,花后40d内,苹果果实吸收整果钙含量的20%左右;从花后40d(套袋)到90d,果实钙吸收量迅速升高,对照果实可吸收整果钙含量的66.1%,套纸袋果实可吸收整果钙含量的73.8%;此外,在果实的成熟期仍有少量的钙吸收。果实套袋后,果实各个部分的钙含量变化与对照果实相比,果皮中钙含量明显低于对照果实,而果肉和果心的钙含量却高于对照果实。     

不同中间砧对苹果果实苹果酸代谢关键酶活性及其相关基因表达的影响

为深入探究中间砧影响苹果果实苹果酸代谢的机理,以SH40实生后代（代号53、111和236）为中间砧嫁接的‘天红2号’苹果树为试材,测定果实发育过程中苹果酸含量、相关代谢酶活性及基因相对表达量。结果表明：果实成熟时,以53号为中间砧嫁接的‘天红2号’果实苹果酸含量显著高于以111号为中间砧的。盛花后30、40、100 ~ 160 d,以53号为中间砧的果实中苹果酸脱氢酶（NAD-MDH）活性显著高于以111号为中间砧的;盛花后30、40和130 d,53号处理的磷酸烯醇式丙酮酸羧化酶（PEPC）活性显著高于111号处理的;盛花后100 d,以111号为中间砧的果实中苹果酸酶（NADP-ME）活性显著高于以53号为中间砧的。基因表达结果显示,盛花后100和160 d,以53号为中间砧的NAD-MDH基因相对表达量显著高于以111号为中间砧的,同时NADP-ME基因表达量也显著高于以111号为中间砧的;盛花后30 和160 d,以53号为中间砧的PEPC基因相对表达量显著高于以111号为中间砧的。     

Cultivar variation in apple peel and whole fruit phenolic composition

The quali-quantitative distribution of phenolic compounds varies considerably between apple flesh and peel, but the concentration of phenolics is substantially higher in the peel than flesh. Because the peel comprises only a small percentage of the entire fruit weight, its significance as a donor of phenolics is disputable. We assessed the contribution of the peel to the total phenolic yield of 19 apple cultivars. Calculations were based on the weight of the whole fruit and the peel (which is frequently discarded) and the concentration of individual phenolic compounds. On average, 8, 24, 32, 50 and 66% of chlorogenic acid, (+)-catechin, (−)-epicatechin, phloridzin, and rutin, respectively, were present in the peel, which constitutes about 6–8% of the whole apple weight. With the exception of chlorogenic acid, 50% or more, on average, of the above phenolics were present in the peel of ‘Granny Smith’, ‘Idared’, ‘Red Rome’, ‘Jonamac’ and ‘Gloster’ apples; the highest percentage was found in ‘Starking Delicious’ apple peel (82%). The lowest peel contribution to total phenolic content per whole apple ranged between 26 and 29% and was observed in ‘Pilot’, ‘McIntosh’ and ‘Prima’ apples. Presented results may be useful for further investigations of the relationship between phenolics and agronomical parameters or future selection of apple genotypes having improved nutritional quality when consumed as fresh or as processed apple products.     

李果实中多酚含量及其抗氧化能力研究

为分析不同李品种果实中多酚含量及其抗氧化能力,以14个李品种为试材,测定果皮和果肉中的多酚含量,采用超氧自由基(O_2~-)清除法、羟自由基(OH·)清除法、DPPH法、FRAP法和TBARS法测定抗氧化能力,比较多酚含量、抗氧化能力的差异,分析多酚含量与抗氧化能力的相关性,比较抗氧化能力测定方法间的相关性。结果表明:(1)李果实中富含多酚并且品种间存在差异,不同品种果皮中含量为1.40~3.37 mg·g~(-1) FW,果肉中含量为0.50~0.97 mg·g~(-1) FW,果皮中含量远大于果肉中含量;果皮中多酚含量较高的李品种为皇后李、猪肝李,其次为黑宝石李、红玫瑰李;果肉中多酚含量最高的为秋姬李,其次为威克逊李。(2)李果皮、果肉多酚提取物均具有较强的抗氧化能力,果皮提取物综合抗氧化能力较强的为皇后李、黑宝石李和猪肝李,果肉的为红美丽李、红玫瑰李和秋姬李。(3)果皮中多酚含量与清除O_2~-、OH·能力及DPPH、FRAP、TBARS均呈极显著正相关,果肉中多酚含量与抗氧化能力呈显著正相关。(4)对5种方法的相关性分析表明,各方法从不同的角度评价李果多酚抗氧化能力,方法间均具有很好的相关性,DPPH法与FRAP法综合评价最佳,可作为主要选择。