黑果枸杞资源分布及其经济价值

本文就国内外对黑果枸杞资源分布、经济价值、开发利用和发展趋势进行了综述。为黑果枸杞在资源开发与环境保护并举,综合利用方面提供科学依据。     

基于rbcL-a和ITS的枸杞鉴别、遗传关系分析及ITS假基因的发现

利用rbcL-a及ITS序列作为分子标记,对14个枸杞种或品种及1个伪品白刺进行了真伪鉴别及遗传关系分析。CTAB法提取总DNA,用通用引物对rbcL-a和ITS序列扩增、克隆、测序及分析,T克隆解决部分样品ITS无法成功测序问题。rbcL-a和ITS序列通用引物可在所有样品中成功扩增,rbcL-a序列全长643 bp,在14个枸杞种或品种中完全一致,与白刺具有45bp(7%)的碱基变异。ITS序列在14个枸杞种或品种中长度变异范围为513-692 bp。采用UPGMA法构建系统树,可区分白刺与枸杞,黑果枸杞和宁夏枸杞各品种分别聚为两支,云南枸杞、韩国枸杞及黄果枸杞则聚在宁夏枸杞大分支内。rbcL-a序列可有效进行枸杞真伪鉴别,ITS序列可用于枸杞品种鉴定及遗传关系分析。此外,本研究首次揭示了枸杞品种及个体内的ITS多态性,发现在枸杞中存在ITS假基因这一现象,为未来利用ITS序列进行枸杞系统进化研究提供一些新的参考。     

枸杞色素及多糖的不同提取次序对其得率及抗氧化活性的影响

为探究先后提取枸杞多糖及枸杞色素时对各自得率的影响。本研究通过分别考察这两种成分在提取过程中的提取溶剂、提取温度、料液比、提取次数及提取时间等因素对枸杞色素和枸杞多糖的得率影响,确定枸杞色素和枸杞多糖在提取次序不同时,两者的最佳提取工艺以及对DPPH·和·OH自由基清除率。结果表明,首先提取枸杞多糖后,枸杞色素的最佳提取工艺为采用正己烷,80℃时,料液比1∶10,提取2次,每次1 h,枸杞色素得率为2.48%,此时枸杞多糖得率为7.45%;而首先提取枸杞色素后,采用了超声辅助提取的方式提取枸杞多糖,发现超声效率为25%,料液比1∶10,提取20 min,枸杞多糖得率为5.23%,此时枸杞色素得率为3.93%。因此,首先提取枸杞多糖,使其平均得率为7.45%,而后提取枸杞色素,其平均得率为2.48%;总体上,枸杞色素1和枸杞多糖1对DPPH·自由基清除率都较高,枸杞多糖1对·OH自由基清除率较高,其抗氧化活性都接近Vc。     

黑枸杞花青苷的研究进展

黑枸杞分布在我国西北部地区,其成熟的浆果中含有丰富的花青苷。黑枸杞花青苷具有抗氧化、抗衰老、降血脂等功效。本文主要综述了黑枸杞花青苷的化学组成及性质、分离纯化方法、药理活性研究和黑枸杞花青苷的应用,为进一步开发和利用黑枸杞花青苷资源提供依据。     

黑枸杞花青苷的研究进展

黑枸杞分布在我国西北部地区,其成熟的浆果中含有丰富的花青苷。黑枸杞花青苷具有抗氧化、抗衰老、降血脂等功效。本文主要综述了黑枸杞花青苷的化学组成及性质、分离纯化方法、药理活性研究和黑枸杞花青苷的应用,为进一步开发和利用黑枸杞花青苷资源提供依据。     

宁夏枸杞深色有隔内生真菌的侵染特征及多样性

【背景】枸杞是享誉中外的名贵药材,深色有隔内生真菌(Dark septate endophytes,DSE)是枸杞内生真菌的重要组成部分。【目的】从宁夏枸杞栽培品种和野生品种的根系分离获得DSE菌株,研究枸杞DSE的群落组成、物种多样性及在宿主植物内的侵染定殖情况。【方法】从宁夏枸杞栽培园采集栽培品种宁杞1号、宁杞3号、宁杞5号、宁杞6号、宁杞7号、宁杞8号以及野生品种黄果枸杞和黑果枸杞共8个枸杞品种的根系,分离DSE菌株,运用形态学特征、r DNA-ITS序列分析进行菌株鉴定,采用回接试验方法确定DSE真菌。【结果】DSE在枸杞根系能形成大量"微菌核"典型结构。从8个枸杞品种根系中共分离获得DSE菌株279株,分属于18个属,具有丰富的物种多样性。镰刀菌属(Fusarium)为各品种的共有属和优势属,相对频率最高达85%。Monosporascus、蓝状菌属(Talaromyces)和俄氏孔菌属(Earliella)为枸杞内首次报道的DSE。枸杞不同品种中DSE群落物种多样性指数、均匀度指数和Simpson指数差异显著。【结论】DSE在枸杞栽培品种及野生品种中具有丰富的生物多样性,能够与枸杞根系形成良好的共生关系,增强了枸杞对生态环境的适应性。     

响应面法优化酶法提取枸杞多糖的研究

选用响应面法优化及正交实验法进行淀粉酶提取枸杞多糖实验设计及分析。通过单因素实验后,正交实验确定淀粉酶酶解提取枸杞多糖的最佳条件为:pH=5.0,温度50℃,时间80 min,加酶量为0.5%,枸杞多糖提取率12.1%;响应面分析确定淀粉酶酶解提取枸杞多糖的最佳条件为酶解温度49.56℃、酶解时间140 min、酶浓度0.3%,枸杞多糖提取率为13.25%。酶法提取枸杞多糖比传统热水浸提提高了枸杞多糖的提取率,反应条件温和,而且通过响应面法进行实验设计和优化比正交实验法能得到更高的枸杞多糖提取率。     

枸杞养肝明目功效研究进展

枸杞不仅具有抗氧化、抗衰老、增强免疫力、调节血脂等功效,而且在预防酒精肝、化学性肝损伤、视网膜病变、青光眼等疾病方面也具有一定的功效。本文对鲜果与干果枸杞主要活性成分含量及功效进行了对比,综述了枸杞在养肝和明目方面的最新研究进展,为开发枸杞的保健和医疗价值提供科学依据。     

宁夏枸杞对枸杞瘿螨为害的内源激素响应及外源水杨酸对枸杞瘿螨的影响

为探索宁夏枸杞对枸杞瘿螨致瘿过程诱导的激素响应及外源水杨酸对枸杞瘿螨的影响,利用LC-MS/MS技术对枸杞瘿螨为害后宁夏枸杞叶片中水杨酸(SA)、茉莉酸(JA)、生长素(Auxin)和脱落酸(ABA)4种内源激素进行测定,并通过浸叶法研究外源SA对枸杞瘿螨侵染过程、虫瘿生长和种群增长的影响。结果表明: 枸杞瘿螨的致瘿行为可引发枸杞叶片中多种内源激素产生变化,其中SA和JA的变化最显著,分别是对照组含量的4.0和13.0倍,而Auxin和ABA的变化不显著;外源SA对枸杞瘿螨虫瘿生长有显著抑制作用,且随时间的延长,抑制作用增强,同时虫瘿内瘿螨种群数量受到显著抑制。枸杞瘿螨能够同时诱导枸杞产生SA和JA抗性,外源SA对枸杞瘿螨虫瘿生长和瘿螨种群数量均具有显著抑制作用,利用外源SA防治枸杞瘿螨具有一定的应用前景。     

枸杞根际土壤真菌群落多样性的高通量测序

【目的】为了解不同枸杞产区枸杞根际真菌多样性的差异,从枸杞根际土壤真菌群落的角度试图解释宁夏枸杞优良品质与其土壤微生物菌群的联系。【方法】采用Mi Seq高通量测序方法,分别将我国4个不同地区枸杞根际土壤样品进行ITS区的高通量测序,并分析了物种组成和丰度、Alpha多样性、Beta多样性和菌群结构,测定不同产区枸杞主要有效成分,同时对枸杞品质和其土壤理化因子及枸杞根际真菌种群多样性的相关性做了分析。【结果】多糖含量和甜菜碱含量均是中宁枸杞高于兴仁和精河,格尔木含量最低;宁夏兴仁、宁夏中宁、新疆精河3个地区菌群结构类似,子囊菌门和结合菌门占总菌群的80%左右,而青海格尔木除了子囊菌门占58%外,壶菌门和新丽鞭毛菌门远远高于其他3个地区,比例占总菌群的近25%;4个地区枸杞根际土壤真菌菌群结构相似性依次为宁夏兴仁、新疆精河、宁夏中宁、青海格尔木。【结论】枸杞根际土壤样品真菌物种组成丰富,不同地区枸杞根际土壤真菌种群结构有一定差异;枸杞主要有效成分含量与枸杞根际土壤真菌种群结构具有一定相关性。     

Influence of host plant on growth and reproduction of Aphis nerii and feeding and prey utilization of its predator Menochilus sexmaculatus

Influence of different physiological stages (young, mature and senescent) of Calotropis gigantea leaves on growth and reproductive ability of A. nerii and feeding, prey utilization, fecundity and lipid content of its predator M. sexmaculatus were investigated. Increased reproductive period, total life span and reproduction of nymphs per female of A. nerii were observed when reared on mature leaves. This relative preference of A. nerii and maximum utilization of mature leaves as compared to other physiological aged leaves are mainly due to changes in the chemical composition such as protein, carbohydrate, lipid, amino acid, nitrogen and phenolic of C. gigantea. Further, aphids reared on mature leaves influenced its predator's (M. sexmaculatus) growth, prey utilization and reproductive performances. Fecundity and longevity were high, while developmental time of predator was shorter on mature leaves fed aphid. Maximum prey utilization and increased efficiency of ingested and digested food of predator was observed on mature leaves reared aphid. The results are interpreted and discussed in relation to plant aphid and predator interaction (tritrophic).     

芝麻种质资源及相关分子生物学研究进展

芝麻是重要的优质传统油料作物,素有"油料皇后"的美称。我国拥有丰富的芝麻种质资源,深入研究、评价和有效利用芝麻种质资源是保护其遗传多样性、拓宽遗传基础进而提高芝麻产量和品质的关键。本文对芝麻种质资源的收集保存、鉴定评价、利用现状、品种选育概况及相关分子生物学研究进展进行综述,期望能对芝麻遗传及应用研究提供一些参考。     

Glucose utilization in vivo and insulin-sensitivity of rat brown adipose tissue in various physiological and pathological conditions.

Brown-adipose-tissue glucose utilization rate and its insulin-sensitivity were measured in vivo in the anaesthetized rat by a 2-deoxy[1-3H]glucose technique. Glucose utilization can be increased 60-fold by insulin, to reach extremely high rates. Glucose utilization and its insulin-sensitivity are modulated in accordance with physiological or pathological conditions.     

Regulation of the β-ketoadipate pathway in Rhizobium japonicum and bacteroids by succinate

Rhizobium japonicum 61-A-101 and its bacteroids catabolize phenol and p-hydroxybenzoate. With phenol as a carbon source, utilization started only after a prolonged lag phase while p-hydroxybenzoate was almost instantancously metabolized. Succinate, which supports rapid growth of Rhizobium japonicum, completely repressed respication of phenol; the oxidation of p-hydroxybenzoate was partially inhibited. Pyruvate, supporting slower growth than succinate, retarded the onset of phenol consumption but did not affect its maximum rate.Catabolite repression of phenol utilization by succinate appears to be a characteristic feature of rhizobia. In Pseudomonas putida which also actively metabolizes phenol, succinate had no effect on phenol utilization.     

我国玉米主产区秸秆资源利用现状及其效果

在我国东北春玉米区、华北玉米区、西南玉米区3个玉米主产区,共125个县、720个村,采用问卷调查和用户调查相结合的方法,对玉米秸秆资源利用现状及其效果进行调查.结果表明:在玉米秸秆资源利用方式中,以秸秆还田、饲料和燃料占绝大多数,研究区域内平均分别占30.8%、26.2%和24.6%.其中东北春玉米区从大到小依次为燃料、饲料和秸秆还田,分别占35.4%、30.8%和19.8%;华北玉米区依次为秸秆还田、饲料和燃料,分别占43.6%、19.9%和17.9%;西南玉米区依次为秸秆还田、饲料和燃料,分别占29.0%、27.9%和20.5%.在研究区域内秸秆焚烧比例均较小,占12.8%;工业原料比例最小,占0.7%.秸秆还田可增加作物产量,东北、华北、西南玉米产区秸秆还田的作物产量分别平均增加632.0、371.6和290.4 kg·hm-2;还可改良土壤状况、减少化肥和有机肥的施入量,其中有机肥施入量减少20%～30%,氮肥减少16%～30%,磷肥减少24%～34%,钾肥减少33%～38%.不同产量水平地块,作物产量随秸秆产量、还田量和还田比例增加而增大.但由于秸秆还田机械不配套,还田质量差,增加了整地除草难度,加重某些病虫害发生,影响后茬作物苗期生长,仍需进行相关配套技术研究.     

黑曲霉菌渣综合利用研究进展

黑曲霉菌渣是黑曲霉经过工业发酵所需产物之后的副产物,资源储量丰富。目前利用黑曲霉生产的制剂种类繁多,对菌渣综合利用的报道却相对较少。已有的研究表明黑曲霉菌渣不仅可作为饲料添加剂、有机肥料或土壤改良剂得到直接应用,也可用于精制,作为食品、药品和化妆品等行业的主要原材料,实现高附加值转化应用。还可作为生物吸附剂用于去除水体中的污染物等。本文结合目前国内外对黑曲霉菌渣在各领域研究及利用现状,综述了黑曲霉菌渣高附加值转化与利用的研究进展,可以为工业发酵废渣资源化利用提供理论参考。     

Terminal sequence studies of high-molecular-weight ribonucleic acid. The 3′-termini of rabbit globin messenger ribonucleic acid

A study of the relative utilization of thymine and thymidine as precursors for DNA synthesis during normal growth in Bacillus subtilis showed that thymine serves preferentially as a precursor for ;repair' synthesis, whereas thymidine is used preferentially for ;replicative' synthesis. Further, evidence was obtained which suggests that during normal growth both ;replicative' and ;repair' DNA syntheses occur simultaneously. ;Repair' synthesis is distinguished not only on the basis of its preferential utilization of thymine but also by its selective inhibition by caffeine. ;Replicative' synthesis, however, is selectively inhibited by 6-(p-hydroxyphenylazo)-uracil. ;Repair' synthesis would seem to be a ;pre-fork' phenomenon and its inhibition is highly lethal to the cell.     

Utilization of modified waste from the antibiotic industry for the production of construction materials

Possible utilization of treated streptomycin fermentation broth modified with waste hydrochloric acid solution followed by lime neutralization was studied. Such a complex additive to concrete increased its strength by 36-41 per cent. With saving cement by 7 per cent the concrete strength increased by 22-29 per cent as compared to the control samples. Therefore, utilization of antibiotic industry waste in production of building material allowed not only to improve its quality but also to lower the environmental pollution.     

Assessing the floodwater utilization potential in a reservoir-controlled watershed: A novel method considering engineering regulations and an empirical case from China

Floodwater utilization can greatly alleviate water resource shortages. Reservoirs and their optimal operation are the most widely used measures to implement floodwater utilization. Quantitatively evaluating the floodwater utilization potential and revealing the relationship between the potential and its influencing factors are preconditions to implementing floodwater utilization; however, few studies have focused on this problem. In this study, we identified the influencing factors via the analysis of reservoir regulation and proposed a floodwater utilization potential evaluation method that considers all influencing factors. The results indicate that reservoir regulation ability, water demand, and ecological water downstream are the main influencing factors of floodwater utilization potential. The floodwater utilization potential decreases as the water demand or reservoir regulation ability increases. Moreover, water demand and reservoir regulation ability are interdependent and interactive to a certain extent. Specifically, reservoir regulation ability can affect only the floodwater utilization potential when the water demand is extremely high. Based on a time-varying operation model, we also evaluated the floodwater utilization potentials of the Longjiaoshan Reservoir (China) under different floodwater utilization statuses. The average annual floodwater utilization potential of the Longjiaoshan Reservoir watershed is 43.06 million m³ under the current floodwater utilization status, and the optimal floodwater utilization strategy is increasing the water demand under the current reservoir regulation ability. This study may contribute to the improved management of flood utilization in such reservoirs.     

Production of 1,2-propanediol from glycerol in Saccharomyces cerevisiae

Glycerol has become an attractive carbon source in the biotechnology industry owing to its low price and reduced state. However, glycerol is rarely used as a carbon source in Saccharomyces cerevisiae because of its low utilization rate. In this study, we used glycerol as a main carbon source in S. cerevisiae to produce 1,2-propanediol. Metabolically engineered S. cerevisiae strains with overexpression of glycerol dissimilation pathway genes, including glycerol kinase (GUT1), glycerol 3-phosphate dehydrogenase (GUT2), glycerol dehydrogenase (gdh), and a glycerol transporter gene (GUP1), showed increased glycerol utilization and growth rate. More significant improvement of glycerol utilization and growth rate was accomplished by introducing 1,2-propanediol pathway genes, mgs (methylglyoxal synthase) and gldA (glycerol dehydrogenase) from Escherichia coli. By engineering both glycerol dissimilation and 1,2-propanediol pathways, the glycerol utilization and growth rate were improved 141% and 77%, respectively, and a 2.19 g 1,2- propanediol/l titer was achieved in 1% (v/v) glycerolcontaining YEPD medium in engineered S. cerevisiae.