滇青、青饼和普洱茶（熟饼）近红外指纹图谱分析

为深入了解滇青（晒青毛茶）、青饼和普洱茶（熟饼）在化学组成方面的异同,为茶类的区分与界别提供进一步的科学依据,对滇青、青饼和普洱茶（熟饼）的近红外化学指纹图谱采用欧氏距离、主成分分析和系统聚类等方法进行了定性判别分析。结果发现,普洱茶（熟饼）近红外指纹图谱与滇青、青饼图谱间的欧氏距离均大于各自组内最大偏差的绝对阈值,而滇青和青饼的组间差异小于各自的组内阈值;在第一主成分和第二主成分得分值散点图上,熟饼样品与青饼和滇青样品间界限分明,而滇青和青饼样品间无明显界限;所有的熟饼样品在系统聚类分析中聚为一类,而青饼与滇青样品聚为一类。因此,青饼的近红外光谱在各方面都与普洱茶（熟饼）样品差异显著,而与其原料滇青（晒青毛茶）十分接近。从化学本质上来说,青饼更接近于绿茶类产品。     

From the micro-scale to the habitat: Assessment of soil bacterial community structure as shown by soil structure directed sampling

Natural structural units of a luvisol under maize crop were studied to assess if soil structure directed sampling could improve the understanding of arrangements of bacteria in spatially constraint location. Three habitats were defined: (i) soil around fine lateral roots (rhizo-aggregates), (ii) soil close to basal roots (core clods) and (iii) unplanted soil between rows (bare soil clods). These habitats were also investigated with maize plants resulting from Azospirillum lipoferum CRT1 inoculated seeds as a model of enhanced fine root system. Rhizo-aggregates were clearly separated from each other (disconnected habitat) in contrast to micro-samples (fragments) from clods, which belong to cohesive macro-structures. Genetic fingerprints on metagenomic extracts were used to characterize the structure of bacterial communities on 95 micro-samples from the three habitats. For eubacteria, automated RISA (Ribosomal Intergenic Spacer Analysis) of ITS (Internal Transcribed Spacer) profiles were performed. PCR-RFLP on nifH gene were used to describe the N-fixer guilds. Exploratory multivariate analyses (PCA and MDS) revealed bacterial community patterns in the sampled habitats. On the basis of ITS profiles, rhizo-aggregates harboured closely related communities, distant from those of the unplanted soil, and each sampled rhizo-aggregate could therefore be considered as a sub-unit of the whole macro-habitat, comprising all the fine roots. The observed low dissimilarity of disconnected rhizo-aggregates is likely to result from the direct influence of maize root tips on the recruitment of rhizosphere bacteria. Molecular fingerprints of nifH from basal root clods (core) were more similar to bare soil than to rhizo-aggregates, indicating similar ecological conditions without, or with, at least, poor maize exudating root influence. Although our study was performed on a limited number of situations, the distribution of bacteria was revealed to be patterned by soil structure units, which is a first step to improve the modelling of microbial ecology in soils.     

30个中国甘薯主栽品种的RAPD指纹图谱构建及遗传变异分析

研究以中国30个甘薯主栽品种为材料,对甘薯RAPD指纹图谱的构建进行了探讨。从102个RAPD引物中筛选出26个多态性丰富的引物用于PCR扩增,共扩增出255条多态性条带,平均每个引物扩增的多态性带数为9.8条。其中S32和S39多态性最高,仅用其中1个引物即能将这30个甘薯品种完全区分开,且由此构建的指纹图谱出现的概率很小,分别为4.77×10^-7（1/221）和1.91×10^-6（1/219）。结果进一步表明,这30个甘薯品种的遗传距离变异幅度较大,为0.0390～0.4306,平均遗传距离为0.3086。RAPD聚类分析表明,地域分布相近的甘薯品种和具有同一亲本的甘薯品种聚在一起,与这些甘薯品种的系谱图一致。     

Development of two microsatellite multiplex PCR systems for high throughput genotyping in Populus euphratica

Eighteen microsatellite primer pairs previously developed at Oak Ridge National Laboratory for Populus tremuloides Michx. and Populus trichocarpa Torr. & Gray were screened for amplification in Euphrates poplar, Populus euphratica Oliv. Thirteen loci were found to express polymorphisms ranging from two to 17 alleles. The eight most variable loci were selected to set up and optimize two multiplex polymerase chain reaction (PCR) assays. Three populations containing altogether 436 trees were used to characterize the selected loci and ascertain their applicability for parentage analysis and genotyping studies. Through cross-checking of clonal identity against sex of the genotyped trees we estimated the maximum error rate for merging genotypes to be less than 0.045. Foundation project: This study was supported by the Deutsche Forschungsgemeinschaft DFG (grant number SCHN 1080/1-1)     

两种微卫星多样PCR系统应用于胡杨高效生产基因型

对已在橡树岭国家实验室建立起来的美洲山杨(Populus tremuloides Michx.)和毛果杨(Populus trichocarpa Torr.＆ Gray)18个微卫星引物进行筛选,用于胡杨相关基因的扩增.发现有13个基因位点可以表达基因多态性,范围是2～17个等位基因.选择了8个最易变的基因位点,来构建和优化2种多样PCR法.用来自3个种群的436株树木表征选择的位点,确定他们在亲缘关系分析、基因型研究的适用性.通过克隆基因型鉴定树木性别的交叉检验,我们估计并入基因型最大误差率小于O.045.     

中国沿海三疣梭子蟹脂肪酸指纹标记的多元分析

为探明分布于中国四大海区的天然三疣梭子蟹群体脂肪酸组成状况及群体差异,并建立群体判定的指纹标记以应用于种质鉴定和资源保护,实验应用脂肪酸指纹标记结合多元分析方法在表型水平上研究中国四大海区中湛江、大连、连云港、东营、舟山和漳州海区6个天然群体秋冬季三疣梭子蟹的脂肪酸差异,并建立了群体判定的脂肪酸指纹标记.结果表明,四大海区6群体三疣梭子蟹脂肪酸存在显著差异(P＜0.01),均含有27种脂肪酸.其中,反式油酸、棕榈酸、DHA、EPA和芥酸这5种脂肪酸的总含量在6群体中均高达82％以上.油酸、二十碳一烯酸、芥酸、ARA和EPA这5种脂肪酸作为脂肪酸指纹标记可以有效的对中国四大海区的6群体秋冬季雌性三疣梭子蟹进行种质鉴定,其综合判别准确率达88.46％.应用所含的27种脂肪酸进行聚类分析显示,四大海区6群体三疣梭子蟹系统聚类结果与地理距离不具有显著相关性,这种脂肪酸组成的群体差异可能与栖息地食物组成差异有关.本研究结果对于中国四大海区三疣梭子蟹的种质鉴定和原产地资源保护具有一定应用价值.     

高山红景天红外指纹图谱共有峰率和变异峰率的双指标序列分析

利用PE-1730傅里叶变换红外光谱仪对8种来源的高山红景天块根粉末进行分析,以红外指纹图谱的共有峰率、变异峰率为计算指标,分析样品相对原生境野生植株样品的共有峰率和变异峰率,建立共有峰率和变异峰率双指标序列分析方法。结果表明:产地相近的H1与H4之间具有较高的共有峰率(88.89%)和较低的变异峰率(12.50%);种质来源地不同、倍性相同的H5与H3通过相同的生境栽培,共有峰率仅为22.22%;种质来源地相同、倍性不同的H5与H6共有峰率达到71.43%;不同种源、不同倍性、相同生境的H6与H8红外图谱的相似度为57.14%。     

云南不同品种有色稻米HPLC指纹图谱的建立及质量评价

建立云南不同品种有色稻米的HPLC指纹图谱,为科学有效的评价其质量提供可靠的方法。采用HPLC-UV方法对样品进行测定,以Venusil ASB-C18(5 μm,250 mm×4.6 mm)为色谱柱;流动相为甲醇和甲酸水,梯度洗脱,流速1.0 mL/min,检测波长262 nm,柱温30℃。采用高效液相色谱法建立了云南不同品种有色稻米的HPLC指纹图谱,对收集的24个不同品种的样品进行分析,结果确定了11个共有峰。对不同品种有色稻米的指纹图谱进行聚类分析和主成分分析,24批样品聚为2类,二者分析结果一致。指纹图谱技术结合聚类分析和主成分分析是评价不同品种有色稻米的有效方法之一,为有色稻米的质量控制提供更全面的参考。     

‘湘农大棉1号’的SSR数字指纹图谱构建及纯度鉴定

为了快速而准确地鉴定杂交棉种子的纯度和真伪,根据亲本材料来源和被推荐使用的SSR核心引物,挑选了33对引物对‘湘农大棉1号’及其亲本进行多态性筛选。结果表明,其中8对SSR引物在父母本及其杂交种扩增出清晰、稳定的多态性性条带,且这些位点在F1中均表现为共显性标记。获得的共显性标记都能用于该杂交种的纯度鉴定,可以用来区别其中混杂的母本、父本及其他种子。将这8对引物在3个材料中扩增得到的01（二进制）数据转换成十进制数据,构建了‘湘农大棉1号’及其亲本的数字指纹图谱。采用多对引物构建的杂交棉数字指纹图谱,能为杂交种的真伪鉴定、纯度检测及亲本提纯等工作提供更加准确的技术指导。     

5个常规香稻品种的指纹图谱及遗传相似性分析

利用48对SSR标记对来源于同一优质香型材料80-66的5个常规香稻品种进行了指纹分析及品种相似性和特异性分析,发现玉针香与玉柱香的遗传差异最小,农香18与玉针香、玉柱香的遗传差异次之,创香5号与玉针香、玉柱香、农香18的遗传差异第三,而板仓香糯为糯稻品种,与其它品种的遗传差异均较大。结果表明:将数字身份证、指纹图谱和坐标图形式的数字指纹三者结合,作为品种的指纹信息,可以更全面的反映该品种的特异性。