Isolation and characterization of fucoidans from five brown algae and evaluation of their antioxidant activity

In this study, we evaluated the chemical property and antioxidant activity of fucoidans isolated from brown algae, Laminaria japonica(LJF), Lessonia nigrescens(LNF), Lessonia trabeculata(LTF), Ascophyllum mackaii(AMF), and Ecklonia maxima(EMF). LJF was less in sulfate content(14.16%) and more in galactose and mannose content(1.08 and 0.68) than the documented early. EMF contained 20%–30% of sulfate and fucose, 0.97 in molar ratio which was lower than that of sulfate to other four fucoidans(1.21–1.41). AMF(162 kDa) and EMF(150 kDa) were the first two largest in molecular weight, which were followed by LJP(126 kDa), LNF(113 kDa) and LTF(105 kDa). The fucoidans isolated these algae showed a wide range of antioxidant activity in vitro. It was found that the reducing power of the isolated fucoidans was positively correlated with their sulfate content and molecular weight. In addition, LNF and LTF at low concentrations exhibited high superoxide and hydroxyl radical scavenging activity. This demonstrated that low molecular weight fucoidans may perform a high antioxidant activity.     

海带微卫星引物对裙带菜群体分析适用性的初步研究

为获得用于裙带菜种质结构和遗传多样性研究的微卫星标记,采用近缘物种转移法分析了15个海带微卫星引物在裙带菜中的应用情况。对38个裙带菜个体进行多样性分析,结果显示:标记SSR002和SSR115不能扩增裙带菜基因组,位点SSR194能扩增,但不具有多态性,其他12个标记均能扩增裙带菜DNA,且都具有检出多态性,其中9个符合哈迪-温伯格平衡。这9个海带微卫星标记检出的等位基因数为34个,从3～5个不等,平均每个位点扩增得到3.8个等位基因。观测杂合度(Ho)、期望杂合度(He)及多态性信息含量值(PIC)的范围分别为0.238～1.000、0.500～0.692、0.413～0.780,9个位点提供的多态性较高,适用于裙带菜遗传学研究。     

Application of restriction site amplified polymorphism (RSAP) to genetic diversity in Saccharina japonica

Restriction site amplified polymorphism (RSAP) was used, for the first time, to analyze the genetic structure and diversity of four, mainly cultivated, varieties of the brown alga, Saccharina japonica. Eighty-eight samples from varieties "Rongfu", "Fujian", "Ailunwan" and "Shengchanzhong" were used for the genetic analyses. One hundred and ninety-eight bands were obtained using eight combinations of primers. One hundred and ninety-one (96.46%) were polymorphic bands. Nei’s genetic diversity was 0.360, and the coefficient of genetic differentiation was 0.357. No inbreeding-type recession was found in the four brown alga varieties and the results of the "Ailunwan" variety using samples from 2 years showed that the variety was becoming less diverse during the selection inherent in the breeding program. Genetic diversity and cluster analyses results were consistent with these genetic relationships. The results show the RSAP method is suitable for genetic analysis. Continuous inbreeding and selection could reduce the genetic diversity effectively; therefore periodical supervision is required.     

北方水稻低温冷害指标持续适用性检验与比较

农业气象指标的可持续适用性检验与比较,对提升农业气象业务能力意义重大。应用北方地区代表县(市)1960—2010年逐日气温资料和历年水稻产量资料,计算冷害温度指标界定水稻冷害发生的正确率,对中国北方水稻延迟型冷害和障碍型冷害常用的指标进行应用效果检验,并比较适用性差异。结果表明,界定水稻延迟型冷害的5—9月气温指标稳定适用,正确率达到78%左右,可持续性好;积温差额指标也比较稳定,可以继续应用;但是积温距平指标判定冷害的正确率较低,多数地方不宜继续使用。界定水稻障碍型冷害的日平均气温、日最低气温及其持续时间指标比较稳定可靠,多数县(市)可以继续应用,但少数县市应暂停使用;日最低气温指标界定冷害的正确率略高于日平均气温指标。多年来,这些指标尽管要素和原理不变,但在适用性及可持续性方面存在一定的年代和区域差异,应选择使用并及时修订过时的指标,以适应气候变化和水稻栽培。     

孤雌生殖海带对氯霉素和潮霉素的敏感性研究

于１９９７年１－４月,以本所培养的孤雌生殖海带为材料,运用统计不傣对氯霉素、潮纱的敏感性,以期得出氯霉素、潮霉素对不同长度孤雌生殖海带的半致死剂量。结果表明,孤生殖海带长度在０．５－１．５ｃｍ时,氯霉素的半致死剂量与海带的长度相关,而潮霉素的半致死剂量怀长度不相关。孤雌生殖海地潮霉互比对氯霉素更敏感,提示潮霉素磷酸转移麦基因有可能成为工程的另一个选择标记。     

海带雌配子体对无机碳的利用

采用ｐＨ漂移技术（ｐＨ－ｄｒｉｆｔ ｔｅｃｈｎｉｑｕｅ）,对海带雌配子体克隆的碳素营养进行了研究。结果表明,海带雌配子体对无机碳的利用能力较弱,其ｐＨ补偿点为８．８５,ＣＯ２补偿点为１．６３５μｍｏｌ／Ｌ。与ＨＣＯ＾－３利用有关的抑制剂：Ａｃｅｔａｚｏｌａｍｉｄｅ（Ａｚ）,４’４’－ｄｉｉｓｏｔｈｉｏｃｙａｎａｔｏｓｉｌｂｅｎｅ－２,２－ｄｉｓｕｌｆｏｎｉｃ ａｃｉｄ（ＤＩＤＳ）,４－ａｃｅｔａｍ     

海带雌性配子体克隆细胞的超低温保存实验

生物种质资源保存的超低温冷冻保存技术在国内外已进行了广泛的研究[1],在藻类种质保存工作方面,绿藻、硅藻、蓝藻[2~6]以及紫菜[7~9]的超低温保存工作也取得了良好的进展.海带配子体(克隆)是一种以有丝分裂方式进行细胞增殖的微小藻体,并可通过两性生殖或单性生殖发育成大型叶状体.     

褐藻酸降解菌感染海带过程中几种酶的作用比较

采用植物单细胞和原生质体游离的方法,研究了5株褐藻酸降解菌感染过程中海带细胞壁的组成成分——褐藻酸的变化。结果表明,海带在5株褐藻酸降解菌感染的初期(前3 d),褐藻酸酶对其单细胞和原生质体的游离率均显著降低,而且随着感染时间的延长,游离率的下降越加明显。3 d过后,随着感染的继续进行,单细胞和原生质体的游离率变化不再明显。表明海带细胞壁组成对褐藻酸降解菌感染发生了响应性变化,而这种变化仅仅发生在褐藻酸降解菌感染的早期阶段。研究结果进一步显示,褐藻酸降解菌感染过程中海带细胞壁组成的变化主要体现在褐藻酸的变化上。     

西南岩溶区发展忍冬的潜力

忍冬俗称金银花,是一种药用植物。发展忍冬既可恢复生态,又能增加收益。通过总结已有文献并分析,认为金银花的主要标识特征包括木犀草苷、绿原酸、元素和土壤中量微量元素与水热条件。通过对比,川西北、横断山和昆明以北岩溶区年日照时数超过2 000h,年降雨量不足1 000mm ,贵州、云南和川南北纬25°以北岩溶区年均气温10～ 16℃ ,与道地金银花产地的气候条件一致;黑色石灰土与贵州的红色石灰土钙、镁、铜、锌含量、盐基饱和度高,基本符合道地金银花的土壤条件,但质地偏粘,需进行改良。比较而言,在西南岩溶区的云南、四川部分黑色石灰土分布区最适宜发展忍冬。在此基础上,提出了加强金银花中木犀草苷、重金属元素测量和影响金银花品质的环境因子的实验研究等建议。     

日本绒螯蟹线粒体DNA序列研究Ⅱ.16S rRNA

参考果蝇、卤虫与锯缘青蟹的线粒体 DNA16 S r RNA基因序列进行了日本绒螯蟹相同基因片段的引物设计、PCR扩增及序列测定 ,得到 56 7bp的碱基序列 ,其 A、T、G、C含量分别为194 bp(34.2 2 % )、2 16 bp(38.10 % )、98bp(17.2 8% )、59bp(10 .4 1% ) ,与果蝇、卤虫及锯缘青蟹类的 16 S r RNA基因片段序列含量相似。