6-BA对Hg2+胁迫下小麦幼苗渗透调节物质及抗氧化特性的影响

为探讨6-苄氨基腺嘌呤(6-BA)对Hg2+胁迫下小麦幼苗生长的调节作用,采用营养液水培法,以小麦品种807为材料,分析了叶面喷施不同浓度的6-BA对Hg2+胁迫下小麦幼苗叶片中渗透调节物质含量、抗氧化酶活性及抗氧化物质含量的影响。结果表明,50mg·L-1 HgCl2处理后,小麦幼苗叶片的可溶性糖和可溶性蛋白含量显著降低,过氧化物酶(POD)和超氧化物歧化酶(SOD)活性下降,还原型抗坏血酸(AsA)和还原型谷胱甘肽(GSH)含量显著降低。叶面喷施一定浓度的6-BA能够提高Hg2+胁迫下小麦幼苗叶片的可溶性糖和可溶性蛋白含量,显著提高小麦幼苗叶片的POD、SOD活性和AsA、GSH含量,降低脱氢抗坏血酸(DHA)和氧化型谷胱甘肽(GSSG)含量,提高小麦幼苗叶片的AsA/DHA和GSH/GSSG比值,从而缓解Hg2+胁迫对小麦幼苗生长的抑制作用。叶面喷施10mg·L-1 6-BA对缓解小麦幼苗Hg2+胁迫效果最好。     

不同类型芒果果肉类胡萝卜素、香气和糖酸品质分析

为研究果肉色泽存在明显差异的芒果果实品质特征,分析了4个浅黄色果肉品种（低类胡萝卜素含量）和4个深黄色果肉品种（高类胡萝卜素含量）的果肉类胡萝卜素、香气、糖和酸含量及组成特征。结果表明：不同品种间类胡萝卜素组分大致相同,其中β-胡萝卜素是各品种中含量最丰富的类胡萝卜素,约占总类胡萝卜素的33％～79％。高类胡萝卜素含量的品种糖含量高、酸含量低,果实香气物质均以单萜烯类为主;低类胡萝卜素含量的品种糖含量较低、酸含量较高,其中‘鹦鹉芒’和‘丰顺无核’果实香气物质分别以酯类和醛类为主,而‘大白玉’和‘白象牙’香气物质以单萜烯类为主。     

菜用大豆种质资源评价与筛选

通过对121份来自全国各地种质资源的大豆生育期、农艺性状、产量性状及菜用大豆相关品质及炭疽病抗性性状进行评价,筛选适宜浙江地区种植的菜用大豆品种资源。结果表明:121份大豆种质资源在生育期、农艺性状、品质性状和炭疽病抗性方面呈现丰富的遗传多样性,各性状种质资源差异显著;生育期为80～128 d,鲜籽单株产量为14.973～148.791 g,可溶性蛋白含量为29.037～136.683 mg·g^-1,可溶性糖含量为4.310～31.130 mg·g^-1,游离氨基酸含量为6.560 7～37.972 7 mg·kg^-1,维生素C含量为4.832～15.460 mg·kg^-1。采用主成分分析法从121份大豆种质资源中筛选出通化平顶香、豫豆19、中黄58、冀豆21、菏豆13、六月黄为适于浙江地区菜用大豆品种选育的资源。     

不同品种桑葚叶总酚含量及其抗氧化活性比较

为了研究不同品种桑葚叶的总酚含量差异及应用价值,以收集引种的40个品种桑葚叶为研究对象,采用超声波辅助提取桑葚叶中酚类物质,以总酚提取率为指标,利用单因素试验和正交试验考察各因素对超声辅助提取桑葚叶总酚提取率的影响;采用DPPH自由基清除能力评价不同品种桑葚叶提取物的抗氧化能力,同时对不同品种桑葚叶中总酚含量及其抗氧化能力进行相关性分析。结果表明：超声辅助提取桑葚叶总酚的最佳工艺条件为：超声温度65 ℃、超声时间30 min、固液比1∶45（g/mL）、乙醇浓度60%,4个因素对桑葚叶总酚提取率影响大小顺序为：超声温度>超声时间>固液比>乙醇浓度。不同品种桑葚叶总酚含量差异较大,其中‘条桑五号’总酚含量最高,为（26.35 ± 0.29）mg/g,‘滇桑’总酚含量最低,为（20.44 ± 0.15）mg/g;不同品种桑葚叶抗氧化活性也存在差异,且趋势与总酚含量基本一致,‘条桑五号’桑葚叶抗氧化活性最强,清除DPPH自由基能力IC₅₀为（77.64 ± 0.34）mg/L,总抗氧化能力（FRAP）TEAC值为（2.58 ± 0.11）mmol/g;‘滇桑’桑葚叶抗氧化活性最弱,清除DPPH自由基能力IC₅₀为（210.30 ± 0.19）mg/L,总抗氧化能力（FRAP）TEAC值为（0.73 ± 0.04）mmol/g。桑葚叶总酚含量与其提取物抗氧化能力呈正相关,选择总酚含量高的桑葚品种栽培,可提高桑葚的综合附加值。     

部分杧果品种果实若干品质特征的比较研究

研究57个杧果品种果实的7项品质特征,结果表明:不同杧果品种果实的可溶性糖、可溶性固形物、可滴定酸含量分别为9.00%～19.88%、11.30%～20.88%、0.02%～0.89%,糖酸比、固酸比分别为16.47～878.86、19.25～882.78,类胡萝卜素含量为6.38～48.60μg/g FW,贮藏期为6～17 d,相对应各项指标的平均值分别为13.51%、14.44%、0.26%、127.36、127.05、23.01μg/g FW、10.17 d,不同品种果实的品质存在显著差异.灰色关联度分析表明,57个杧果品种的综合品质以留香杧最佳.完熟时绿色果皮品种的果实可溶性糖含量显著高于红色果皮品种,且糖酸比值和同酸比值显著高于红色与黄色果皮品种.多胚品种的可溶性糖含量显著高于单胚品种.相关分析表明,芒果可溶性糖含量与可溶性固形物含量及类胡萝卜素含量呈极显著或显著正相关,可滴定酸含量与糖酸比、固酸比呈极显著负相关.     

外源5-氨基乙酰丙酸对干旱胁迫下降香黄檀幼苗生长、根系生理特性的影响

以1.5年生降香黄檀幼苗为试材,通过溶液培养的方式,研究不同浓度(0、10、25、50、100 mg/L)的5-氨基乙酰丙酸(5-ALA)对聚乙二醇(PEG-6000)模拟干旱胁迫条件下降香黄檀幼苗的生长发育、根系性状、光合色素含量、抗氧化酶活性、丙二醛含量、有机渗透调节物质含量等生理生化指标的影响。结果表明:PEG-6000胁迫14 d后,降香黄檀幼苗的苗高、地径、根、茎、叶干重、叶片相对含水量、叶绿素a含量、叶绿素b含量、类胡萝卜素含量显著下降,MDA含量显著上升,而抗氧化酶(SOD、POD)活性和有机渗透调节物质含量(可溶性糖、可溶性蛋白质)、根系活力明显下降。同时,一定浓度的外源5-ALA降低了PEG-6000引起的降香黄檀幼苗生理上的干旱胁迫,其中以25 mg/L处理时效果最好,且与PEG处理相比,叶片相对含水量、叶绿素a含量、叶绿素b含量、类胡萝卜素含量、SOD与POD活性、可溶性糖与可溶性蛋白含量、根系活力分别提高了157.95%、34.44%、33.33%、24.49%、84.66%,87.66%、59.23%、76.8%、62.72%,MDA含量则降低了37.81%。因此,根系施用外源5-ALA可促进干旱胁迫下降香黄檀幼苗的生长,并可通过提高根系的抗氧化酶活性和渗透调节物质含量来增加其抗旱性,其适宜浓度为25 mg/L。     

不同类型甜菜品种根中Mg^2＋-ATP酶活性和产质量的关系

测定不同类型甜菜品种各生育时期根中Mg2+-ATP酶活性、可溶性总糖、可溶性蛋白含量和产量、含糖率.结果表明,在幼苗期和叶丛繁茂期,Mg2+-ATP活性呈先上升后下降趋势,从块根增长期直至糖分积累期,Mg2+-ATP酶的活性逐渐增强,并保持在全生育期最高水平.不同类型品种间存在差异,在各生育时期高糖型品种Mg2+-ATP酶活性较强.根中Mg2+-ATP酶活性与根中可溶性总糖呈正相关,与甜菜根的成熟进程正相关;Mg2+-ATP酶活性与可溶性蛋白质含量呈负相关,对可溶性糖的积累方面,二者的作用刚好相反.高糖型品种的可溶性总糖含量较高,相应的根中蛋白质含量很低,Mg2+-ATP酶活性较高.     

外源钙及其抑制剂对蝴蝶兰幼苗耐热性的影响

为探讨Ca²⁺信号参与调节蝴蝶兰耐热性形成的生理机制,采用适宜浓度的外源Ca²⁺（CaCl₂）、胞外Ca²⁺螯合剂（EGTA）和质膜Ca²⁺通道抑制剂（LaCl₃）溶液喷施蝴蝶兰幼苗植株,以喷施蒸馏水为对照,测定高温胁迫下蝴蝶兰幼苗植株的抗氧化酶活性、丙二醛、渗透调节物质和光合色素含量的变化。结果表明,与对照相比,CaCl₂处理能显著增强超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性,增加脯氨酸、可溶性蛋白、可溶性糖、叶绿素和类胡萝卜素含量,显著降低丙二醛含量,减轻了蝴蝶兰幼苗的高温伤害,而LaCl₃和EGTA处理不同程度地降低SOD、POD和CAT活性,降低脯氨酸、可溶性蛋白、可溶性糖、叶绿素和类胡萝卜素含量,显著增加丙二醛含量,使蝴蝶兰幼苗受害加重。由此认为,Ca²⁺信号可通过参与抗氧化酶活性、脯氨酸和光合色素的代谢过程来调控蝴蝶兰幼苗耐热性的形成。     

干旱胁迫下外源海藻糖对糯玉米幼苗生理特性的影响

以苏玉糯5号为供试材料,研究干旱胁迫条件下外源海藻糖对糯玉米幼苗根系和叶片抗氧化系统及渗透调节物质的影响。结果表明,干旱胁迫显著降低叶片叶绿素含量和根系活力,喷施外源海藻糖后这两类物质含量增加。干旱胁迫下喷施外源海藻糖增加玉米根系和叶片中可溶性蛋白、可溶性糖、抗坏血酸(AsA)、还原型谷胱甘肽(GSH)含量,增强糯玉米幼苗根系和叶片的超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)等活性,降低超氧阴离子产生速率(O2-)、丙二醛(MDA)等含量。外源海藻糖处理下叶片中可溶性糖、可溶性蛋白、AsA和GSH含量增加幅度大于根系,叶片中丙二醛含量降幅大于根系。表明喷施外源海藻糖缓解干旱胁迫对叶片伤害效果大于根系。干旱胁迫下喷施外源海藻糖能够增强糯玉米抗旱能力,减小干旱伤害。     

2个杧果品种果实品质及其构成研究

以红杧六号和桂热82号两个杧果品种为试材,研究其果实品质特征及其构成,结果表明:红杧六号果实单果重、可食率、类胡萝卜素含量、可滴定酸含量均高于桂热82号,而可溶性糖含量和糖酸比低于桂热82号。高效液相色谱(HPLC)分析表明,芒果果实共含3种糖、11种有机酸和4种类胡萝卜素,即果糖、葡萄糖和蔗糖;草酸、酒石酸、奎尼酸、苹果酸、抗坏血酸、乳酸、α-酮戊二酸、柠檬酸、富马酸、琥珀酸和没食子酸;堇菜黄素、β-胡萝卜素、叶黄素和番茄红素。其中,蔗糖、苹果酸和堇菜黄素分别为芒果的主要糖、有机酸和类胡萝卜素种类。两个品种果实不同糖、有机酸和类胡萝卜素组分的含量多数存在显著差异。综合而言,桂热82号的果实品质和风味较好。     

Change in Colour and Antioxidant Content of Tomato Cultivars Following Forced-Air Drying

Three New Zealand grown tomato (Lycopersicon esculentum L.) cultivars, Aranka, Encore, and Flavourine, were analysed for colour (CIELAB L^∗ a^∗ b^∗ values), ascorbic acid, total phenolics, lycopene, and total antioxidant activity (ABTS assay). Colour analyses of the air-dried tomatoes showed that the colour degradation as measured by the L^∗ a^∗ b^∗ values was minimal, and the colour was not significantly different (p < 0.05) between each of the dried cultivars. In general, there was no significant difference (p < 0.01) between the fresh cultivars in terms of antioxidant components or total antioxidant activity. The average values obtained for antioxidant components in the three fresh cultivars were: ascorbic acid, 276 mg/100 g DM, total phenolics, 613 mg gallic acid equivalents (GAE)/100 g dry matter (DM) and lycopene 38 mg/100 g DM. Total antioxidant activity of the fresh cultivars was 2917 μmole Trolox equivalent antioxidant capacity (TEAC)/100 g DM. Following forced air-drying treatment at 42 ^∘C for 48 hr, all cultivars showed significant decreases in ascorbic acid, total phenolics and total antioxidant activity, and increases in extractable lycopene contents. This study was undertaken to identify cultivars that would provide the best colour and nutrient contents after commercial air drying.     

Antioxidant in Mango (<Emphasis Type="Italic">Mangifera indica</Emphasis> L.) Pulp

This work was carried out to investigate the pulp composition of four mango cultivars (Haden, Tommy Atkins and Ubá) at the ripening stage in relation to three components with antioxidant potential (total phenolics, carotenoids and ascorbic acid). Total phenolic compound content was estimated by the Folin-Ciocalteu reagent and total carotenoid content by spectrophotometry at 450 nm. The contents of β-carotene and total vitamin C (ascorbic acid and dehydroascorbic acid) were quantified by high performance liquid chromatography. Differences were found among the four mango cultivars in all the components analyzed. The content of phenolic compounds ranged from 48.40 (Haden) to 208.70 mg/100 g (Ubá); total carotenoid from 1.91 (Haden) to 2.63 mg/100 g (Palmer); β-carotene from 661.27 (Palmer) to 2,220 μg/100 g (Ubá) and total ascorbic acid ranged from 9.79 (Tommy Atkins) to 77.71 mg/100 g (Ubá). These results corroborated previous information that mangoes are a good source of antioxidants in human diet.     

高酯型儿茶素含量的茶树资源筛选研究

以福建省茶树品种园780份资源为试验材料,依外部形态特征初步筛选出45份较有希望的品种或株系。用等度高效液相色谱法,分析检测这45个品种或株系的春梢、夏梢、秋梢酯型儿茶素含量,筛选高酯型儿茶素含量的茶树特异资源。结果表明:新梢酯型儿茶素含量在不同品种、株系间差异很大;春梢、夏梢、秋梢的酯型儿茶素含量变化范围分别为5.21%～24.03%、3.05%～20.31%、2.89%～19.66%,平均值分别为16.08%、14.73%、9.96%,变异系数分别为22.26%、24.10%、40.76%。同一品种或株系新梢的酯型儿茶素含量呈季节性变化,大多数(约71.11%)表现为:春梢>夏梢>秋梢。有5个品种、株系(033、505、509、524、1005),春、夏、秋三季,酯型儿茶素平均含量高于19%,为超常规水平的高酯型儿茶素茶树特异资源,可作为品质遗传改良或直接应用于提取酯型儿茶素的重要材料。有8个品种、株系[033、505、509、510(1)、510(2)、524、1001、1005]新梢酯型儿茶素含量在儿茶素总量中所占比例高达80%以上(一般品种为68%),可作为提取茶多酚、儿茶素的特种材料。     

１-甲基环丙烯处理对中花芥蓝低温保鲜品质的影响

研究不同1-MCP（0.1、1.0、10.0 μL/L）浓度处理结合聚乙烯袋包装和低温贮藏（10 ℃）对中花芥蓝采后营养品质的保鲜效果。结果表明：叶片中的叶绿素、维生素C、可溶性蛋白含量分别是茎薹的25、2、5倍，而茎薹中的可溶性糖含量是叶片的4.5倍。贮藏20 d后，芥蓝叶片黄化，花蕾开放并脱落；芥蓝在贮藏过程中，叶绿素和维生素C含量的下降比可溶性糖和可溶性蛋白含量明显，叶片营养成分的下降比茎薹明显。1-MCP（1.0 μL/L）处理可有效保持芥蓝的营养品质，贮藏20 d后叶片基本保持绿色、花蕾部分开放     

菠萝种质果实可溶性糖组分及含量分析

采用高效液相色谱法对50份菠萝种质果实中可溶性糖组分及含量进行测定。结果表明,菠萝果实的可溶性糖主要由果糖、葡萄糖和蔗糖组成,其中蔗糖含量最高,占总糖比例的40.85％~76.89％,葡萄糖次之,果糖最低。蔗糖在各种质间的变异相对稳定;果糖和葡萄糖变异较大,分别为22.50％和22.67％。根据单糖与双糖的比例,可将不同的菠萝种质分为蔗糖积累型和单糖积累型。相关性分析结果显示,果实内各糖组分均与总糖呈极显著的正相关,果糖和葡萄糖含量呈极显著相关性。因此,在评价菠萝果实中糖度风味要同时考虑果糖、葡萄糖和蔗糖     

Total phenolics,flavonoids, antioxidant capacity in rice grain and their relations to grain color,size and weight

Total phenolics, flavonoid contents and antioxidant capacity from a wide collection of rice germplasm were measured, and their relations to grain color, grain size and 100-grain weight were investigated. Highly significant genotypic differences were observed in total phenolics, flavonoid contents and 2,2-azino-bis-(3-ehylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical cation antioxidant capacity. They displayed an increasing order in the white rice, red rice and black rice, yet several white rice had higher phenolics and flavonoids contents than the red rice. Significant positive pair-wise correlations were found among the phenolics, flavonoid contents and antioxidant capacity, and the coefficient between the phenolic contents and antioxidant capacity was extremely high (r = 0.96). Among all rice accessions, the grain color parameters had negative correlations with the phenolics, flavonoid contents and antioxidant capacity (p < 0.001). The negative correlation between a* and antioxidant capacity, and the positive correlation between H° and antioxidant capacity were consistent within the respective white rice and red rice groups. Flavonoid contents had positive correlation with grain length and length to width ratio, and had negative correlation with the 100-grain weight among all rice accessions. It was also found that 100-grain weight still had negative correlations with phenolics, flavonoid contents and antioxidant capacity within the white rice genotypes. These relationships may serve as indexes to indirectly select breeding lines high in the phenolics, flavonoids and antioxidant capacity. Principal component analysis including the information for phenolics, flavonoids, antioxidant capacity, grain color parameters, grain size and 100-grain weight extracted five principal components that explained 83.7% of the total variances. The results of this study may provide new opportunities for rice breeders and eventually commercial rice growers to promote the production of rice with enhanced nutritional quality.     

茶树品种对生物量累积与养分分配的影响

为明确不同品种茶树的物质、养分积累及分配特性,本研究以10龄的龙井43、薮北和奥绿茶树为研究对象,考察了3个品种茶树的生物量以及养分量在地上部留存、新梢采摘、修剪和凋落物中的分配。结果表明,地上部留存的生物量以及新梢产量均为龙井43>薮北>奥绿;而修剪物的生物量则呈相反的趋势;凋落物的生物量未在品种间表现出明显差异。5种主要养分元素在3个品种间均表现为叶片含量高于树茎;但在新梢、修剪物和凋落物中的分配则与品种相关。地上部留存部分的养分累积量为龙井43>薮北>奥绿,而通过采摘、修剪与凋落物形式移出的养分总量表现为奥绿>龙井43>薮北;其中龙井43新梢养分累积量占地上部移出总量的比例最高（63.7%~85.0%）,薮北为37.4%~60.2%;修剪是奥绿转移物质和养分的主要形式,其养分累积量占地上部总移出量的66.6%~91.2%。本研究结果有利于根据品种优势和茶园生产模式制定针对性的养分管理措施,为优化茶园施肥、提高养分利用效率提供依据。     

Color and Antioxidant Characteristics of Some Fresh Fig (Ficus carica L.) Genotypes from Northeastern Turkey

Fruit skin color, total phenolics, total anthocyanins, soluble solids content, titratable acidity and total antioxidant capacity in fresh fruits of a number of local and well-known fig (Ficus carica L.) genotypes and cultivars grown in northeastern Turkey were determined. TEAC (Trolox equivalent antioxidant capacity) and FRAP (ferric reducing antioxidant power) assays were used to determine total antioxidant capacity. Fruit skin color of genotypes were found to be very diverse, i.e., light green, light purple, purple, dark purple and black. The content of total phenolics, soluble solids content (SSC) and titratable acidity greatly varied in the range from 24 to 237?mg of gallic acid equivalent per 100?g fresh weight, 18.60 to 26.30?% and 0.16 to 0.47?% in local genotypes and studied cultivars. In general, total antioxidant capacities determined by two methods expressed higher values in the local fig genotypes compared with the cultivars. The results suggested that genotype is the main factor that determines difference in the composition of bioactive compounds in figs and provide information on putative health benefits locally grown genotypes.     

Antioxidants in potato

The content of compounds in potato that may act as antioxidants in the human diet is not widely appreciated. Carotenoids are present in the flesh of all potatoes. The contents mentioned in the literature range from 50 to 100 μg per 100 g fresh weight (FW) in white-fleshed varieties to 2000 μg per 100 g FW in deeply yellow to orange-fleshed cultivars. The carotenoids in potato are primarily lutein, zexanthin, and violaxanthin, all of which are xanthophylls. There is just a trace of either alpha or beta-carotene, meaning that potato is not a source of pro-vitamin A carotenes. In potatoes with total carotenoids ranging from 35 to 795 μg per 100 g FW, the lipophilic extract of potato flesh presented oxygen radical absorbance capacity (ORAC) values ranging from 4.6 to 15.3 nmoles α-tocopherol equivalents per 100 g FW. Potatoes contain phenolic compounds and the predominant one is chlorogenic acid, which constitutes about 80% of the total phenolic acids. Up to 30 μg per 100 g FW of flavonoids are present in the flesh of white-fleshed potatoes with roughly twice the amount present in red and purple-fleshed potatoes. The predominant flavonoids are catechin and epicatechin. Red and purple potatoes derive their color from anthocyanins. The skin alone may be pigmented, or the flesh may be partially or entirely pigmented. Whole unpeeled with complete pigmentation in the flesh may have up to 40 mg per 100 g FW of total anthocyanins. Red-fleshed potatoes have acylated glucosides of pelargonidin while purple potatoes have, in addition, acylated glucosides of malvidin, petunidin, peonidin, and delphinidin. The hydrophilic antioxidant activity of solidly pigmented red or purple potatoes is comparable to brussels sprouts or spinach. In red and purple potatoes with solidly pigmented flesh with levels of total anthocyanin ranging from 9 to 38 mg per 100 g FW, ORAC ranged from 7.6 and 14.2 umole per g FW of Trolox equivalents. Potato contains on average 20 mg per 100 g FW of vitamin C, which may account for up to 13 % of the total antioxidant capacity. Potatoes should be considered vegetables that may have high antioxidant capacity depending on the flesh composition.     

Determination of Antioxidant Constituents in Cactus Pear Fruits

An analytical study was carried out on the presence of antioxidant constituents and the in vitro antioxidant capacity in the extracts of three species of Spanish red-skinned cactus pear fruits (Opuntia ficus-indica, Opuntia undulata and Opuntia stricta). The cactus pear fruit extracts were analyzed for determined constituents: ascorbic acid, flavonoids (quercetin, isorhamnetin, myricetin, kaempferol and luteolin), betalains, taurine, total carotenoids and total phenolics. The antioxidant capacity was assessed by means of two different methods: the 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (Trolox equivalent antioxidant capacity) method and the 2,2-diphenyl-1-picrylhydrazyl radical method. Opuntia ficus-indica fruit extract had the strongest antioxidant capacity and taurine content. O. stricta fruits were the richest in ascorbic acid and total phenolics, whereas O. undulata fruits showed the highest carotenoid content. Quercetin and isorhamnetin were the main flavonoids detected. This study provides basic information on the presence of bioactive compounds and antioxidant capacity in extracts of cactus pear fruits, in order to consider these extracts as ingredient for the production of health-promoting food.