4-PU和6-BA对‘汕油523＇花生上胚轴愈伤组织诱导及不定芽发生的影响

以‘汕油523’花生上胚轴为外植体,研究细胞分裂素4-PU和6-BA对愈伤组织诱导及不定芽发生的效应。结果表明,当MS培养基含有4-PU 0．1mgm和6-BA4mg／L培育20d时,愈伤组织形成率为100％;0．1mg/L4-Pu与适宜浓度的6-BA（1～4mg／L）共同作用,促进上胚轴不定芽发生,不定芽形成与芽伸长的适宜培养基配方分别为MS＋4-PU 0．1mg/L＋6-BA2mg／L和MS＋4-PU0．1mg／L＋6-BA4mg／L;0．5mg／L4-PU对不定芽出芽率、芽数与长度的作用均大于其与不同浓度6-BA混合作用的效果。     

玉竹的组织培养与快速繁殖

以玉竹[Polygonatum odoratum (Mill.) Druce]根状茎、叶片和茎段为外植体,于附加不同激素配比的MS培养基中诱导愈伤组织、不定芽和不定根,探讨增殖培养和植株再生的条件.结果表明,叶片和茎段外植体诱导愈伤组织和芽的分化率很低;而根状茎外植体易于培养,有较高的诱导率和增殖倍数,其愈伤组织、不定芽和不定根的诱导率分别可达87%、90%和99%以上.适宜根状茎外植体愈伤组织诱导的培养基为MS+1.0 mg/L 6-BA+0.5 mg/L NAA,有利于增殖和丛生芽分化的培养基为MS+2.0 mg/L 6-BA+0.5 mg/L IBA和MS+3.0 mg/L 6-BA+0.1 mg/L NAA,而1/2MS+3.0～5.0 mg/L NAA适宜诱导试管苗生根培养.试管苗的移栽成活率可达85%以上.     

紫色大花矮牵牛组织培养与植株再生

矮牵牛叶片外植体在MS+6-BA 1.0mg/L+NAA 0.1mg/L培养基上培养3周后产生致密的浅绿色愈伤组织;转入芽分化培养基MS+6-BA 0.5mg/L+4-PU 0.5mg/L+NAA 0.1mg/L 1周后,从愈伤组织表面不断分化产生幼芽;待幼芽长至3cm时转接至生根培养基1/2MS+NAA 1.0 mg/L+GA₃0.5mg/L中生根,长成完整植株。     

三倍体毛白杨组织脱分化培养与植株体再生

采用毛白杨三倍体幼叶作为外植体进行组织培养,以MS为基本培养基获得了再生植株。从NAA和IAA与6-BA间进行的18个正交试验中,选择出适宜脱分化培养基MS+6-BA 0.5mg/L+NAA 0.1mg/L,对三倍体毛白杨愈伤组织诱导率为87.6%。5种生长素与6-BA配比的再分化培养基中,12MS+IAA 0.1mg/L+6-BA 0.1mg/L对不定芽的分化诱导率可达到68.5%;MS+6-BA 0.5mg/L+NAA 0.01mg/L的培养基可使单芽直接增殖出7.4个芽。在MS+IBA 1.0mg/L的生根培养基上,试管苗的生根率可达85.7%。     

金线莲外植体筛选及愈伤组织诱导研究

以金线莲茎段、叶片、茎片、不定芽为试材,分别在添加6-BA、ZT、NAA、KT 5个不同处理的MS及1/2MS培养基上培养,诱导愈伤组织。结果表明,以茎段、茎片、不定芽为外植体,在MS + 6-BA 2.0 mg/L + NAA0.5 mg/L、MS + NAA 2.0 mg/L + KT 0.1 mg/L和MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + ZT 0.2 mg/L培养基中培养,均能成功诱导愈伤组织。不定芽为诱导愈伤组织最佳外植体,最佳培养基为MS + 6-BA 2.0 mg/L + NAA 0.5 mg/L + KT 0.2 mg/L。     

鼎湖山紫背天葵组织培养及植株再生

选用紫背天葵无菌苗叶片为外植体,建立了离体培养体系,并探讨其愈伤组织生长和不定芽诱导的适宜培养条件。通过研究得出:愈伤组织诱导的最佳培养基是MS+2,4-D 1.00 mg/L+6-BA 1.0 mg/L+LH 200 mg/L+CH200 mg/L+YE 200 mg/L,愈伤组织诱导率为96.88%。不定芽诱导培养基为MS+6-BA 1.0 mg/L+LH 200 mg/L+CH 200 mg/L+YE 200 mg/L,不定芽诱导率为77.3%。不定芽转至1/2MS培养基中均可100%生根并长成完整植株,小苗移栽成活率达到90%。     

彩色马蹄莲的组织培养

以彩色马蹄莲芽眼为外植体,在添加不同激素配比的MS培养基上进行培养.结果表明:(1)较适宜诱导愈伤组织的激素组合是1.5 mg/L Zt+0.1 mg/L NAA、3.0 mg/L 6-BA+0.1 mg/L NAA或0.5 mg/L 2,4-D+0.1 mg/L NAA,出愈率分别为94.12%、100%和86.67%;较适宜诱导不定芽的激素组合是2.0 mg/L 6-BA+0.1 mg/L NAA,芽丛诱导率可达87.3%;芽增殖较适宜的激素组合是2.0 mg/L 6-BA+0.1 mg/L NAA或2.0 mg/L KT+1.0 mg/L NAA,而且在继代培养中,交替使用这两种激素组合,繁殖系数可达4倍以上;生根培养基以1/2 MS+0.3 mg/L NAA+0.2 mg/L IAA较为适宜,生根率达95%以上.(2)彩色马蹄莲小块茎形成的主要影响因素是培养基中的蔗糖浓度,最适宜蔗糖浓度为10%;10 mg/L多效唑和8 mg/L NAA对小块茎的形成有明显的促进作用,而分裂素则表现出较强的抑制作用.     

濒危物种绒毛皂荚组织培养快繁技术的初步研究

以绒毛皂荚(Gleditsia vestita Chun et How ex B.G.Li)种子为外植体,通过愈伤组织诱导、不定芽分化增殖、生根和驯化移栽,建立了绒毛皂荚组织培养的快速繁殖体系。结果表明:1)绒毛皂荚子叶和胚轴在MS+6-BA3.0 mg/L+KT 0.4 mg/L+IAA 0.3 mg/L培养基上同步诱导出愈伤和芽,愈伤组织诱导率达到90.5%,同步分化率高达77.9%;2)不定芽增殖的最佳培养基为1/2MS+6-BA 1.0 mg/L+IBA 0.3 mg/L+NAA 0.2 mg/L,培养20 d后,增殖倍数为4.0;3)MS+NAA 0.5 mg/L+IAA 0.25 mg/L条件下,生根率高达100%,且移栽后植株长势好,成活率达90%以上。     

白刺花胚性愈伤组织诱导及体细胞胚发生和萌发

探讨不同因素对白刺花下胚轴、子叶2种外植体胚性愈伤组织诱导及体细胞胚发生和萌发的影响。以B5和MS为基本培养基,研究2,4-D、6-BA和TDZ对白刺花下胚轴和子叶胚性愈伤组织的诱导;在MS培养基上添加不同浓度2,4-D,研究胚性愈伤组织增殖情况;采用ABA,探究对体细胞胚发生的影响。结果表明:下胚轴比子叶更易诱导胚性愈伤组织,筛选出2种外植最佳的胚性愈伤组织诱导培养基均为MS+2.0 mg/L 2,4-D+0.5 mg/L TDZ+0.5 mg/L 6-BA,胚性愈伤组织诱导率分别为77.3%和41.0%。15.0 mg/L ABA、0.2 mg/L 2,4-D和2.0 mg/L 6-BA有利于体细胞胚发生,1/3MS+0.2 mg/L NAA+0.1 mg/L 6-BA+2.0 g/L活性炭+25 g/L蔗糖+7 g/L琼脂的培养基可使体细胞胚萌发率达80%以上,再生植株移栽成活率高达90%。白刺花外植体种类及培养基类型均会影响胚性愈伤组织的诱导,其中下胚轴诱导效果优于子叶;MS培养基较适合启动细胞脱分化形成愈伤组织,2,4-D对胚性愈伤组织的增殖保持有调控作用,ABA有利于体细胞胚的发生。     

不同植物生长调节剂对铁皮石斛(Dendrobium candidum)再生的影响

本实验以铁皮石斛无菌苗茎段为外植体,通过添加不同浓度的植物生长调节剂,诱导铁皮石斛愈伤组织形成与分化,建立铁皮石斛组织培养再生体系。结果表明,外植体接种5 d后,在改良MS培养基上添加2 mg/L PBU和0.05 mg/L IAA,可达到100%的愈伤诱导率。将愈伤组织接种在MS培养基上,添加0.1 mg/L NAA和0.5 mg/L 6-BA,不定芽诱导率为90.8%。适合铁皮石斛芽增殖培养基为:MS+7 g/L琼脂+30 g/L蔗糖+100 mg/L Vc+0.5 mg/L 6-BA+0.2 mg/L NAA。PBU浓度为0.5 mg/L,NAA浓度为0.05 mg/L时,芽苗生长情况良好,最适合用于不定芽伸长。铁皮石斛最适生根的培养基为:MS+7 g/L琼脂+30 g/L蔗糖+100 mg/L Vc+0.5 mg/L IBA,生根率可高达94.1%。本研究成功建立了铁皮石斛高效再生体系。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain.

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.     

Identification and composition of the tonsillar and anal enterococcal and streptococcal flora of dogs and cats

Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent. hirae was found almost as often as Ent. faecalis. Most Ent.faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol. Typical Ent. avium as well as atypical Ent. avium -like strains were seen in dogs, while the related species Ent. raffinosus was associated with cat tonsils. Enterococcus cecorum also occurred mainly in cats. Certain atypical strains, presumptively identified as Ent. cecorum , shared characteristics with Ent. columbae.
The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep. canis. Streptococcus canis and Strep. bovis predominated in anal swabs. The canine Strep. suis differed from the common porcine strains in fermenting mannitol.
Forty-seven of the 288 isolates examined could not be identified or related to known species. The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described.     

Molecular characterisation of species and genotypes of Cryptosporidium and Giardia and assessment of zoonotic transmission

The molecular characterisation of species and genotypes of Cryptosporidium and Giardia is essential for accurately identifying organisms and assessing zoonotic transmission. Results of recent molecular epidemiological studies strongly suggest that zoonotic transmission plays an important role in cryptosporidiosis epidemiology. In such cases the most prevalent zoonotic species is Cryptosporidium parvum. Genotyping and subtyping data suggest that zoonotic transmission is not as prevalent in the epidemiology of giardiasis. Molecular characterisation of Cryptosporidium and Giardia is a relatively recent application that is evolving as new genes are found that increase the accuracy of identification while discovering a greater diversity of species and yet unnamed taxa within these two important genera. As molecular data accumulate, our understanding of the role of zoonotic transmission in epidemiology and clinical manifestations is becoming clearer.     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

Comparison of BMI and percentage of body fat of Indian and German children and adolescents

Today, serious health problems as overweight and obesity are not just constricted to the developed world, but also increase in the developing countries (Prentice 2006, Ramachandram et al. 2002). Focusing on this issue, BMI and percentage of body fat were compared in 2094 schoolchildren from two cross-sectional studies from India and Germany investigated in 2008 and 2009. The German children are in all age groups significantly taller, whereas the Indian children show higher values in BMI (e.g. 12 years: Indian: around 22 kg/m2; German: around 19 kg/m2) and in the percentage of body fat (e.g. 12 years: Indian: around 27%; German: around 18-20%) in most of the investigated age groups. The Indian children have significantly higher BMI between 10 and 13 (boys) respectively 14 years (girls). Indian children showed significant higher percentage of body fat between 10 and 15 years (boys) and between 8 and 16 years (girls). The difference in overweight between Indian and German children was strongest at 11 (boys) and 12 (girls) years: 70% of the Indian but 20% of the German children were classified as overweight. In countries such as India that undergo nutritional transition, a rapid increase in obesity and overweight is observed. In contrast to the industrialized countries, the risk of overweight in developing countries is associated with high socioeconomic status. Other reasons of the rapid increase of overweight in the developing countries caused by different environmental or genetic factors are discussed.     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000