中国对虾人工选育快速生长群体不同世代间的AFLP分析

利用7对AFLP引物组合检测了中国对虾连续五代选育群体基因组DNA的遗传结构,根据AFLP分析结果计算了选育世代群体间的遗传相似系数和遗传距离.结果表明,AFLP标记表现出较高的多态检测效率,7对引物共产生500余条带,平均每对引物组合检测到33.7个多态性标记,平均杂合度为0.0854～0.1025,非常适合于遗传多样性分析.结果显示,随着选育世代的增加,选育群体的遗传多样性呈现下降趋势,但随着选育时间的延长,群体之间的分化逐渐降低,群体的遗传结构开始趋于稳定,成为一个品系.     

利用扩增片段长度多态性(AFLP)研究坛紫菜的遗传变异

应用AFLP技术对浙江普陀列岛、渔山列岛和南麂列岛野生坛紫菜、福建野生厚型及薄型以及栽培坛紫菜的两个表型分化类型进行了研究。结果表明：坛紫菜的遗传变异较为丰富，共记录了528个位点，其中16个为单态位点，其余的为多态位点，多态位点比例达到96.97%。其遗传距离与地域分布正相关，说明不同的环境因素可能是造成坛紫菜遗传变异的主要因素。对遗传距离进行UPGMA和Neighbor-joining聚类分析表明具有薄型叶片性状的浙江野生坛紫菜和福建野生薄型坛此菜聚合，而福建野生厚型与栽培具厚型叶片，当地俗称为木耳菜的样本聚合。该结果基本清楚地反映了坛紫菜表型特征的分化。栽培薄型叶片俗称鸡毛菜样本在不同聚类方法中分别于外侧并入不同的分支。在福建野生坛紫菜与养殖坛紫菜的AFLP图谱中仅发现了三条与叶片性状相关的谱带：具有厚型叶片性状的坛紫菜共有的ACC-CAA(100)和ACT-CAG(232)，具有薄型叶性状的坛紫菜共有的ACC-CAA(490)。     

利用AFLP技术研究海湾扇贝不同养殖群体的遗传结构及其分化

采用AFIP分子标记技术对我国海湾扇贝的4个不同地理群体共80个个体利用7对引物组合进行了遗传多样性分析。4群体的多态位点比例分别为：加拿大养殖群体48．8235％,墨西哥湾养殖群体49．2914％,秦皇岛养殖群体38．2353％,浙江养殖群体41．1765％。平均杂和度分别为0．1878,0．1886,0．1265和0．1618。遗传距离介于0．1188～0．0941之间。4个群体的Fst为0．1883。根据遗传距离绘制了UPGMA聚类图。4个群体间的遗传关系如下：加拿大群体和浙江群体聚为一支,墨西哥湾群体和秦皇岛群体聚成一支,最后这两支聚在一起。试验结果表明,经过长时间累代养殖的浙江、加拿大、墨西哥湾群体仍保持较高的杂合度,与引种时间最短的(2年)、最为接近美国自然群体的秦皇岛群体比较,以上3个群体没有出现多态位点比例和杂合度显著下降的现象。     

青海大黄油菜粒色性状AFLP标记的筛选和SCAR标记转化

大黄油菜是青藏高原特有的一个白菜型油菜地方品种,种皮颜色鲜黄.已知大黄油菜的黄籽性状受到1对隐性基因（Brsc1）控制,且该基因被定位于白菜型油菜的第9连锁群上.为获得更多与种皮色泽紧密连锁的分子标记以及共显性标记,本研究利用大黄油菜和褐籽白菜型油菜09A-126为亲本构建BC1分离群体和F2群体,利用AFLP与BSA相结合的方法,通过筛选256对引物结合,共获得5个与种皮色泽连锁的AFLP标记.5个特异AFLP片段分别被回收、克隆、测序,并与白菜型油菜基因组序列进行同源比对,均与A09染色体表现同源.将5个AFLP标记成功转化成5个SCAR标记,用F2群体对SCAR标记进行检测,筛选到1个共显性标记.     

Can near‐infrared reflectance of green coffee be used to detect introgression in Coffea arabica cultivars?

Most new coffee cultivars disseminated over the last 15 years are derived from the Timor Hybrid (Coffea arabica × C canephora). Introgression of genes from the C canephora genome has been estimated at between 9 and 29% of the genome. It has been shown that introgression can have a negative impact on the cup quality of cultivars derived from the Timor Hybrid. Consequently, coffee buyers or roasters may wish to assess whether the coffee they are purchasing comes from introgressed varieties. The possibility of distinguishing between non‐introgressed Arabicas and genotypes carrying chromosome fragments introgressed from C canephora was investigated (i) using some classical chemical compounds (caffeine, chlorogenic acids, trigonelline, fat and sucrose) and (ii) using a new approach based on spectra acquired by near‐infrared reflectance of green coffee. Near‐infrared spectra were obtained for 129 samples from two collections (Nicaragua and Costa Rica) of introgressed and non‐introgressed coffee trees. The spectral collections were treated by principal component and factorial discrimination. When the introgressed coffee trees were compared with the non‐introgressed trees using the chemical compounds, small but significant differences were found in caffeine, trigonelline and chlorogenic acid contents. However, the small variations in those compounds are not enough to detect introgression. The spectral collections treated by principal component and factorial discrimination made it possible to class from 92.30 to 94.87% of the analysed samples correctly, while the percentages of correctly classified samples in the verification file varied from 88.23 to 94.11%. The NIRS method appears to be an efficient method for determining whether a green coffee comes from an introgressed variety. Copyright © 2005 Society of Chemical Industry     

Comparison of phenotypic (Biolog System) and genotypic (random amplified polymorphic DNA-polymerase chain reaction, RAPD-PCR, and amplified fragment length polymorphism, AFLP) methods for typing Lactobacillus plantarum isolates from raw vegetables and fruits

The diversity of 72 isolates of Lactobacillus plantarum, previously identified from different raw vegetables and fruits, was studied based on phenotypic (Biolog System) and genotypic (randomly amplified polymorphic DNA-polymerase chain reaction, RAPD-PCR, and amplified fragment length polymorphism, AFLP) approaches. A marked phenotypic and genotypic variability was found. Eight clusters were formed at the similarity level of 92% based on Biolog System analysis. The most numerous clusters grouped isolates apart from the original habitat. Almost all isolates fermented maltose, d,l-lactic acid, N-acetyl-d-mannosamine and dextrin, and other typical carbon sources which are prevalent in raw vegetables and fruits. None of the isolates fermented lactose and free amino acids. At high values of linkage distance, two main clusters were obtained from both UPGMA (unweighted pair group with arithmetic average) dendrograms of RAPD-PCR and AFLP analyses. The two clusters mainly separated isolates from tomatoes and carrots from those isolated from pineapples. At 2.5 linkage distance, a high polymorphism was found and several sub-clusters were formed with both analyses. In particular, AFLP allowed the differentiation of 55 of the 72 isolates of L. plantarum. The discriminatory power of each technique used was calculated through the Simpson's index of diversity (D). The values of the D index were 0.65, 0.92 and 0.99 for Biolog System, RAPD-PCR and AFLP analyses, respectively.     

A new simplified AFLP method for wine yeast strain typing

A simplified method of AFLP (Amplified Fragment Length Polymorphisms) is presented for typing yeast present during wine fermentations. The changes introduced allowed analysis by gel electrophoresis and considerably reduced the need for equipment. Another remarkable improvement was the use of non-labelled primers which reduces the cost of the analysis. This method was applied to reference strains from culture collection to test the reliability of the technique. A total of 180 colonies isolated from a spontaneous fermentation were typed into eleven different strains of Hanseniaspora uvarum, six of Hanseniaspora vineae, four of Candida zemplinina, and eleven of Saccharomyces cerevisiae. This method is suitable for typing yeast strains for routine grape and wine ecology analysis.     

In vitro-propagated Miscanthus × giganteus plants can be a source of diversity in terms of their chemical composition

Miscanthus × giganteus is a triploid hybrid propagated vegetatively from rhizomes or in a tissue culture, so its clones are characterised by a very low genetic diversity. Giant Miscanthus is cultivated mainly for biomass used as biofuel; depending on its chemical composition, it can be used in many industries. The goal of this work was to determine whether regenerants obtained in tissue culture can be a source of new forms characterised by different biomass yield and energy values as well as by their concentration of cellulose, hemicellulose and lignin. In the study the number and height of stems as well as the dry weight, ash and water mass fraction of biomass were estimated. The study was performed on Miscanthus plants propagated from rhizomes obtained from two different locations in Poland (Zabierzów – Z and Radzików – R), and on regenerants (Iv) obtained from Z plants. The results indicated that somaclonal variation occurs in M. × giganteus cultures and that regenerants show low polymorphic variation compared to donor plants. Plants propagated in an in vitro culture showed the lowest stem height, but the highest number of stems per plant. Dry matter yield was greatest in the R group, while regenerants demonstrated the highest level of hemicellulose fraction and lowest cellulose and lignin concentration. Energy value was the highest for Z plants, but Iv plants showed energy values on the same level as those of R plants. The data suggest that in vitro-propagated plants may be a source of new Miscanthus forms.     

AFLP analysis of type strains and laboratory and industrial strains of Saccharomyces sensu stricto and its application to phenetic clustering

Using nine primer pairs, amplified fragment length polymorphism (AFLP) analysis was conducted to characterize industrial, laboratory and type strains of Saccharomyces sensu stricto. S. cerevisiae, S. bayanus, S. carlsbergensis and S. paradoxus had species-specific AFLP profiles, with some variations among the strains. Nineteen wine, ale, bakery, whisky and laboratory strains of S. cerevisiae were differentiated by two primer pairs, while out of 19 strains of sake yeast, two groups consisting of two and eight strains were not differentiated using nine primer pairs. A phenogram of 41 strains of S. cerevisiae, two strains of S. bayanus, the type strain of S. pastorianus, three strains of S. carlsbergensis, one hybrid strain of S. cerevisiae and S. bayanus and the type strain of S. paradoxus was obtained by the unweighted pair group method, using arithmetic averages (UPGMA) based on the percentage of shared AFLP fragments of each sample pair. This phenogram demonstrated clear separations of S. cerevisiae, S. bayanus, S. carlsbergensis and S. paradoxus. However, S. pastorianus ATCC 12752(T) showed the highest percentages of shared fragments with the strains of S. bayanus, and formed a cluster with them. Except for the type strain of S. pastorianus, the percentages of shared fragments showed a similar tendency with reported data of DNA relatedness. The cluster of S. cerevisiae separated into three subclusters: one consisting of sake and shochu strains and a whisky strain; another consisting of bakery, wine, ale and whisky strains; and a third consisting of laboratory strains.     

烟草AFLP分析体系的建立与优化

以10份烟草种质资源为试材,对AFLP分析过程中包括DNA的提取质量和浓度、MseⅠ/EcoRⅠ以及T4DNA连接酶的浓度、反应时间和反应温度、以及其反应体系的组成等影响因素进行了研究。建立了一种适于烟草AFLP银染技术的优化体系。该体系中各优化因素为模板DNA的用量为400 ng,酶切体系中MseⅠ和EcoRⅠ各加入4U,T4DNA连接酶加入2.8U,采用酶切与连接在同一体系中一步完成,其酶切连接温度为37℃,反应时间为7 h。并对预扩增、选择性扩增和银染的效果进行了检测,以引物E-ACT/M-CAC构建了烟草种质资源的AFLP指纹图谱,该图谱扩增带多,多态性强,且质量好。