培养料配方对姬松茸子实体产量和氨基酸、有害物含量的影响

采用3种培养料配方,研究其对姬松茸(N2)产量和氨基酸含量有害物含量的影响。结果表明:姬松茸子实体中镉含量比培养料中高184～215倍,姬松茸有富集镉的特性。配方1、配方2、配方3子实体镉含量分别为13,10,9.6mg/kg,产量分别为9.5,9.4,8.8kg/m2,氨基酸总量分别为27.59%,25.80%,20.58%。配方2子实体中镉含量显著低于配方1,其产量、氨基酸总量与配方1相近;配方3的产量、氨基酸总量最低,与配方1、配方2差异显著,表明采用KH2PO4代换过磷酸钙,可以降低子实体镉含量,而不宜用化学氮代换牛粪;配方1子实体砷含量最高,与配方2、配方3差异显著。3种配方子实体中六六六、滴滴涕、敌敌畏、四环素等有害物含量基本相同。     

湖北省双孢蘑菇子实体中重金属铅镉含量及来源分析

双孢蘑菇Agaricus bisporus子实体中重金属铅、镉含量分析结果表明,铅、镉的背景值含量分别为0.636mg/kg和0.127mg/kg,样品中铅含量的范围为0.087－2.40mg/kg,镉含量的范围为0.038－0.301mg/kg。在两种不同栽培模式下,子实体中铅含量均有显著差异,但镉的含量并无显著差异。相关性分析表明,子实体中铅来源于覆土而与培养料无关,而镉的来源与栽培方式有关,覆土和培养料中的镉含量均影响子实体中的镉含量。     

不同产地松茸氨基酸与矿质元素的比较研究

以西南地区的三种松茸子实体为材料 ,用柱前衍生高效液相色谱法和原子吸收分光光度法分别对松茸子实体的氨基酸和矿质元素进行了测定 ,氨基酸的测定结果表明 :采自四川通江的松茸子实体的氨基酸总含量最高 ,为 10 .5 82 % ;其次为采自重庆的松茸子实体为 9.6 0 7% ;最低的为采自云南昌隆的松茸子实体 ,为 3.381%。矿质元素的测定结果表明 :所测定的七种元素中 ,含量较高的有三种 ,分别为K ,Ca和Mg ,平均含量分别为 3.1× 10 4mg/Kg ,1.6 2× 10 3mg/Kg和 5 .5 8× 10 2mg/Kg。在这三种松茸子实体中云南昌隆的Fe ,Mn含量最高 ,分别为 6 2 .2 82mg/Kg和 6 .0 6 4mg/Kg ;重庆的Cu含量最高 ,为 5 2 .84 5mg/Kg;Zn的含量在这三种子实体中差异不大。     

蛹虫草对锌的耐性与富集特征

在培养基内添加不同量的锌,研究其对蛹虫草子实体的形成、子实体和菌丝体生物量、子实体多糖含量和葡萄糖含量的影响,以及蛹虫草子实体和菌丝体对锌的富集能力。结果表明锌对上述各项都有影响。液体培养条件下,锌浓度在453906mg/L范围内可以促进菌丝体生长,锌浓度超过4077mg/L时,菌丝生长受到抑制。培养基锌的浓度在4077mg/L以下时,蛹虫草菌丝体锌的富集量随着液体培养基锌浓度的提高而提高。固体培养条件下,锌含量在226453mg/kg范围内可以促进蛹虫草子实体生长,并且在此含量范围内,蛹虫草子实体中葡萄糖含量较高。培养基锌含量在680906mg/kg时,子实体多糖含量较高。培养基锌含量在2038mg/kg以下时,蛹虫草子实体中锌的富集量随着培养基锌含量的提高而提高,在培养基锌含量为2038mg/kg时,子实体中锌的含量达到28570mg/kg(干重)。     

RNA复合物对松茸子实体的作用

施用核糖核酸和5,-核苷酸试验,其对生长于林间的松茸子实体的活化作用。在形成子实体之前将RNA关联物的水溶液直接洒入带有菌丝群落的松树林地表层。为了估计处于生长和形成子实体时期菌丝的状况对高菌根含量根中核苷、麦角固醇和磷脂的含量进行分析。与对照相比,RNA关联物的水溶液对提高核苷、麦角固醇和磷脂含量有作用,施用RNA关联物后9天磷脂含量迅速增加,RNA关联物有助于形成密集的菌丝群落。试验最后结果表明在形成子实体的两周时间内关联物使松茸子实体的产量和数量显著增加。     

不同北虫草菌株产类胡萝卜素分析

通过对不同来源北虫草菌株子实体中提取的色素进行定性分析并对其含量进行测定,获得类胡萝卜素含量高的北虫草菌株。结果表明,浓硫酸反应中溶液在两相交界处呈现特征性的蓝绿色,色素提取液在400～600 nm范围内有波长分别为415、440和460 nm的3个吸收峰与类胡萝卜素标准的吸收光谱一致,证明子实体中提取的色素为类胡萝卜素;6个菌株子实体类胡萝卜素的含量差异较大,且J菌株的类胡萝卜素的含量最高,达到5.021 mg/g。     

林芝地区松茸营养成分分析及松茸多糖的提取分离

以林芝地区5个样点采集的野生鲜松茸子实体为材料,对水分、粗蛋白、粗脂肪、粗纤维、粗多糖、氨基酸、灰分、VC及矿质元素的含量、有效成分进行测定,并以正交法确定了松茸多糖提取的最佳工艺条件。结果表明:各组分的平均质量分数分别为89.45%、12.02%、7.74%、7.84%、9.53%、8.67%、5.76%、0.5046 mg.g-1;矿质元素中K、P含量较高,平均24.063mg.g-1、5.278 mg.g-1,Zn含量高于其它常见食用菌子实体,平均0.5648 mg.g-1,Ca的含量偏低,平均0.4356 mg.g-1;同时含有甾体等有效成分。松茸多糖提取主次因素和最优工艺为乙醇体积分数85%、料水比为1:10、温度80℃、时间4 h,在此条件下粗多糖得率为8.98%。     

硒和碲对缓解糜子镉毒害及减少籽粒镉积累的调控效应

提高糜子(Panicum miliaceum)镉耐受性与低积累能力对镉污染地区糜子的安全生产具有重要意义。该研究以镉耐受和镉敏感糜子品种为材料,通过苗期水培和全生育期盆栽试验,分析不同形态硒和四价碲对镉胁迫下糜子生长、根系形态、镉吸收转运和籽粒矿质营养含量的影响。结果表明,外源添加硒和碲能缓解镉毒害,其中有机硒缓解效果较好。与单独镉处理相比,硒和碲能够促进根系直径增加并抑制镉吸收,最高可使根系镉含量降低33%。此外,硒和碲能够增加细胞壁和液泡中镉的占比,提高镉耐受性。叶面喷施硒提高了糜子籽粒中锌、锰和钼等矿质营养元素含量。无机四价硒能更有效地抑制镉从营养器官向籽粒的转运,在5mg·kg^–1镉处理下,可使镉敏感和镉耐受品种籽粒镉含量分别降低11.3%和20.3%。综上,外源添加硒能够显著提高糜子镉耐受性并减少籽粒镉积累。研究结果可为镉污染地区糜子的安全生产提供参考。     

秋华柳和枫杨幼苗对镉的积累和耐受性

以秋华柳和枫杨当年实生幼苗为研究对象,采用向土壤添加外源镉(CdCl₂ · 2.5H₂O)的形式设置了0(对照组)、10 、20 、50、100 mg/kg 5个处理,研究了镉胁迫下秋华柳和枫杨幼苗的生长、生物量变化和根茎叶镉含量,并评价了两树种的耐性指数(Ti)、转移系数(Tf)和生物富集系数(BCF)。结果表明:(1)在镉含量为10 mg/kg时,秋华柳和枫杨幼苗基于生长和生物量参数的耐性指数(Ti)分别为91.72和91.62,与对照组相比无显著变化,其余各组(20、50、100 mg/kg)则显著低于对照植株(P<0.05);(2) 土壤镉浓度小于20mg/kg时,秋华柳植株茎、叶镉积累量分别高达61.73 mg/kg、163.04 mg/kg,根镉积累量为91.05 mg/kg;枫杨植株茎、叶镉积累量最高分别为7.9 mg/kg、5.25 mg/kg,仅为秋华柳茎、叶的12.8%和3.2%,根镉积累量高达190.68 mg/kg;(3) 除对照外,秋华柳幼苗各部分镉含量为叶＞根＞茎,转移系数(Tf)介于0.789-1.513之间,枫杨幼苗各部分镉含量为根＞茎＞叶,转移系数(Tf)介于0.037-0.044之间,远远小于秋华柳Tf;(4)秋华柳和枫杨幼苗在土壤镉浓度为10 mg/kg时具有很高的生长适应性和耐性,秋华柳根吸收的镉向地上部分转移能力、地上部分积累镉的能力都远远大于枫杨,生物富集系数(BCF)进一步证实了这一特性。研究证明,秋华柳植株具有很高的镉耐性、镉转移能力及地上部分积累镉的能力,适合于镉污染严重区域的植物修复。     

氮离子束注入姬松茸担孢子的生物学效应研究

氮离子束注入与紫外线辐射对姬松茸担孢子萌发的影响显著不同,表现出一定程度的马鞍型效应.不同剂量的氮离子束注入姬松茸担孢子,其产生的生物学效应不同:氮离子注入束流为200×2.6×1013N /cm2,筛选到一株箱栽生物学效率提高47.0%的姬松茸新菌株AbML11;氮离子注入束流为400×2.6×1013N /cm2,筛选到一株子实体呈现白色突变的姬松茸新菌株AbML7;氮离子注入束流为500×2.6×10"N13/cm2,筛选到一株具有AEC抗性突变的姬松茸新菌株AbML2.     

Effect of cadmium on lipid peroxidation and activities of antioxidant enzymes in growing pigs

Malondialdehyde (MDA), glutathione (GSH) content, total antioxidant capacity (T-AOC) levels, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione transferase (GST) activities were studied in serum, liver, and kidney of growing pigs after graded doses of cadmium administration in diets. One hundred ninety-two barrows (Duroc x Landrace x Yorkshire), with similar initial body weight 27.67±1.33 kg, were randomly allotted into 4 different treatments with 3 replications (16 pigs per replication). The treatments received the same basal diet added with 0, 0.5, 5.0, and 10.0 mg/kg cadmium (as CdCl₂), respectively. The results showed pigs treated with 10 mg/kg cadmium significantly decreased average daily gain (ADG) (p<0.05) and increased feed/gain ratio (F/G) (p<0.05) compared to the control. In this treatment, the contents of MDA increased significantly (p<0.05), GSH concentrations, T-AOC levels, and the activities of SOD, GSH-PX, and GST decreased significantly (p<0.05). The results indicate 10 mg/kg cadmium could decrease pig antioxidant capacity after extended exposure and cadmium-induced increase lipid peroxidation might not be only the result of the possibility of lower level of GSH but could also be as a result of direct action of cadmium on peroxidation reaction.     

镉污染条件下水稻对假单胞菌TCd-1微生物修复的生理响应

微生物在修复重金属污染土壤中发挥重要作用。为阐明假单胞菌TCd-1降低水稻镉吸收的机理,通过加镉土培盆栽试验,在10 mg/kg镉处理下,对比研究了接种菌株对2种镉耐性不同水稻品种(特优671、百香139)镉含量、根系活力、光合作用、抗氧化酶活性及抗氧化物质含量的影响。结果表明：与10 mg/kg镉处理相比,接种假单胞菌TCd-1后水稻“特优671”和“百香139”的根、茎、叶、糙米的镉含量分别依次降低了30.4%、39.1%、40.7%、29.2%和52.2%、51.7%、18.4%、38.8%;提高了2种水稻的根系活力、光合作用,促进了水稻的生长;“特优671”、“百香139”叶片的超氧化物歧化酶(Superoxide dismutase, SOD)活性分别提高了7.3%、138.5%,过氧化物酶(Peroxidase, POD)活性提高了82.0%、106.2%,过氧化氢酶(Catalase, CAT)活性提高了58.8%、172.7%;叶片的类黄酮含量提高了139.4%、73.6%,总酚含量提高了27.2%、23.1%;超氧阴离子含量降低了44.2%、29.0%,丙二醛(Mal...     

Exogenous spermidine elevating cadmium tolerance in Salix matsudana involves cadmium detoxification and antioxidant defense

In this study, exogenous spermidine role on Salix matsudana tolerance to cadmium was evaluated. Spermidine and cadmium presented antagonistic effects on the biomass, copper and zinc concentrations in S. matsudana. cadmium mainly distributed in the cell wall of subcellular fraction; 46.97%–60.43% of cadmium existed in a sodium chloride-extracted form. Cadmium contents in roots, leaves, and twigs ranged from 2002.67 to 3961.00, 111.59 to 229.72, and 102.56 to 221.27?mg/kg, respectively. Spermidine application elevated cadmium concentrations in the roots, cuttings, and cell wall and the ratio of deionized water-extracted cadmium, but decreased cadmium levels in the twigs and leaves and the fractions of cadmium extracted by ethanol and sodium chloride, respectively. Putrescine and malondialdehyde were important indicators of cadmium-induced oxidative damage. Exogenous spermidine alleviated the accumulation of superoxide anion, hydrogen peroxide, malondialdehyde via promoting the levels of spermidine, soluble protein, superoxide dismutase, reductive ascorbate, glutathione reductase, and glutathione peroxidase in S. matsudana leaves under the corresponding cadmium stress. The results indicated that S. matsudana was a candidate for cadmium rhizoremediation and extraction in leaves; the spermidine application enhanced the cadmium tolerance of S. matsudana through promoting cadmium accumulation in roots, cell wall, and less bioactive chemical forms and the antioxidative ability.     

Effect of dietary calcium on cadmium absorption and retention in suckling rats

The effect of calcium supplementation on absorption and retention of cadmium in the suckling period was evaluated in Wistar rat pups of both sexes. Animals were maintained in the litters with the mother rats and supplemented with 1%, 3% or 6% calcium (as CaHPO₄×2H₂O) in cow's milk by artificial feeding from day of birth 6 through 14. All rats were exposed to cadmium (as CdCl₂×H₂O) either orally or parenterally. Oral cadmium dose of 0.5 mg/kg body weight a day was administered through nine-day period of calcium supplementation and parenteral cadmium dose was injected subcutaneously in a single dose of 0.5 mg Cd/kg body weight prior to calcium supplementation. On experimental day 10 (at the age of pups of 15 days) all animals were killed and the liver, kidneys, brain and carcass (body without organs and skin) were removed for element analyses. Cadmium and essential elements calcium, zinc and iron were analysed in the tissues by atomic absorption spectrometry. Results showed that after oral exposure cadmium concentrations in all calcium-supplemented groups were significantly decreased in the organs and carcass and that the effect was dose-related. No such effect of calcium was found after parenteral cadmium exposure. Calcium supplementation per se significantly increased calcium concentration in the carcass and had no effect on iron in organs and zinc in carcass. It was concluded that calcium supplementation during the suckling period could be an efficient way of reducing oral cadmium absorption and retention without affecting tissue essential trace element concentrations.     

镉胁迫下植物促生菌密歇根克雷伯氏菌TS8和Lelliottia jeotgali MR2对拟南芥生长及镉富集的影响北大核心CSCD

为了研究镉胁迫下植物促生菌密歇根克雷伯氏菌(Klebsiella michiganensis)TS8和Lelliottia jeotgaliMR2对拟南芥(Arabidopsis thaliana)生长及镉富集的影响,文中以野生型拟南芥为试验材料,将其种植在不同镉浓度的土壤基质中,并施入MR2和TS8菌悬液。低浓度镉处理组(LC)为购买的基质营养土,初始镉浓度为14.17 mg/kg,高浓度处理组(HC)为在购买的基质营养土上额外喷洒200 mg/kg Cd^(2+)。结果表明,相比对照组,不同浓度镉胁迫下喷施MR2菌悬液均可显著促进拟南芥的生长,而TS8和MR2_TS8混合菌液仅在高浓度镉胁迫下表现出一定的促生效果。但值得关注的是,不同浓度镉胁迫下TS8菌悬液可显著降低拟南芥的地下部对重金属镉的富集(60%和59%),并有效提高地上部对重金属镉的富集(234%和35%)。此外,单菌和混合菌均能显著提高土壤中可还原态镉向酸可提取态镉转化,促进植物吸收,降低土壤总镉含量。因此,针对不同环境下,合理配施植物促生细菌在提高作物产量或修复土壤镉污染中具有一定的应用价值。     

干旱胁迫下镉处理对互叶醉鱼草幼苗生长、镉积累及光合生理的影响

为探究干旱条件下,互叶醉鱼草(Buddleja alternifolia Maxim.)幼苗对重金属镉胁迫的生长及光合生理响应机制,以两年生互叶醉鱼草幼苗为试验材料,设置对照与干旱两个水分处理组(土壤相对含水率分别为:65%—60%,35%—30%),每个水分处理条件下再分别设置3个镉处理浓度(0.28、(0.6+0.28)、(1.2+0.28)mg/kg),共6个处理。测定不同水分及镉处理对互叶醉鱼草生长、生物量、光合参数及体内重金属含量的影响。结果表明:干旱与镉复合胁迫下植物的存活率为100%。镉胁迫、干旱与镉复合胁迫均不同程度抑制了互叶醉鱼草幼苗生长、生物量积累、植株的光合作用及叶绿素含量,且其光合和叶绿素含量的降幅明显大于单一镉胁迫。镉胁迫下,互叶醉鱼草幼苗单株最高镉富集量为69.33 mg/kg,而复合胁迫下单株最高镉富集量为50.68 mg/kg。以上结果表明:干旱胁迫能够加重镉胁迫对植物的影响,使复合胁迫下互叶醉鱼草生长、光合生理及镉富集能力下降。但单一镉胁迫下,互叶醉鱼草对镉具有更强的耐受性,并有较高的生物富集能力,且干旱与Cd复合胁迫下互叶醉鱼草幼苗仍有一定的镉积累量。因此在干旱半干旱区园林绿化以及Cd污染地区的生态建设中,互叶醉鱼草是一种具有巨大应用潜力和前景的灌木树种。     

Effect of zinc on cadmium toxicity to the amphipod Gammarus pulex

The freshwater amphipod Gammarus pulex was sampled from several sites in Northumberland, England and analysed for total body zinc and cadmium concentrations.The toxicity of cadmium to animals from the different sites was determined and a positive relationship was found between the initial total body zinc concentration and the ability to survive in an artificial medium containing 0.5 mg 1^–1 cadmium as cadmium sulphate.Exposure in the laboratory to a low concentration of zinc (0.01 mg 1^–1) as zinc sulphate for two weeks resulted in a decreased susceptibility to cadmium poisoning.