Phylogeography and genetic diversity of Psammophis schokari (Serpentes) in North Africa based on mitochondrial DNA sequences

The snake Psammophis schokari has a widespread distribution across North Africa, and in Morocco/Western Sahara is represented by three different morphotypes: striped, unicoloured and the Western-Sahara morph. ND4 mitochondrial DNA sequences from 28 specimens comprising 20 P. shokari, two P. aegyptius, one P. elegans, two P. sibilans, one P. condanarus and two outgroups were analysed. Within P. schokari we identified four genetic lineages (Morocco/Western Sahara, Mauritania, Algeria and Israel) with a genetic divergence ranging from 4-5%, less than that typically found between different species. Surprisingly, Moroccan/Western Sahara and Algerian lineages are the most divergent ones. This geographic substructuring may be due to severe climate changes in the Sahara desert between the Miocene and Pleistocene associated with expansion/contraction phases of this desert. Psammophis aegyptius is the sister-taxon of Psammophis schokari with a high level of genetic divergence between them (10.7%) supporting the recognition of P. aegyptius as a distinct species. The three Moroccan/Western Sahara colour morphotypes form one genetic lineage, indicating that colour pattern does not reflect a different phylogenetic history, and is probably an ecological adaptation to the local environment.     

分子生物学技术在真菌种性检测中的应用

本文介绍了当前应用于真菌分类学中的六种分子生物学技术（G C值、DNA互补,RNA技术,RFLP、RAPD五种核酸技术和一种蛋白质技术——同工酶技术）的原理、操作。适用范围及其应用状况,为食、药用真菌研究者和生产者提供参考。     

家蚕基因组中的分子标记遗传图谱

遗传标记既是基因组研究的重要内容，又是构建遗传图谱、研究生物多样性、育种、基因定位与克隆等的基因。目前，已有多项分子标记技术用于家蚕基因组的研究，并构建了多种分子标记遗传图谱，包括限制性酶切片段长度多态性（简称RFLP）、DNA随机扩增多态性（简称RAPD）、扩增片段长度多态性（简称AFLP）、简单重复序列PCR（简称SSR－PCR）等。本文就分子标记技术构建的家蚕基因组分子标记遗传图谱进行了讨论。     

A fine map for maternal lineage analysis by mitochondrial hypervariable region in 12 Chinese goat breeds

As the fast pace of genomic research continues to identify mitochondrial lineages in animals, it has become apparent that many independent studies are needed to support a robust phylogenetic inference. The aim of this study was thus to further characterize the maternal lineage, proposed to originate in southwestern region of China, using a wider survey of diverse goat breeds in China. To this end, we sequenced the mitochondrial hypervariable region 1 (HVR1) of the mtDNA control region in 145 goats of 12 Chinese breeds. Phylogenetic analysis revealed that Chinese goats were classified into four distinct lineages (A, B, C and D) as previously reported. A Mantel test and the analysis of Analysis of Molecular Variance (ANOVA) indicated that there was not an obvious geographic structure among Chinese goat breeds. Population expansion analysis based on mismatch distribution and Fu's Fs statistic indicate that two expansion events in Chinese goats occurred respectively at about 11 and 29 mutational time units ago, revealing two star-like subclades in lineage B corresponding to two population expansion events. Moreover, lineage B sequences were presented only in the breeds of southwestern or surrounding regions of China. Multiple lines of evidence from this study and previous studies indicate that for Chinese goats mtDNA lineage B originated from the southwestern region of China.     

Control of rabies: epidemiology of rabies in Asia and development of new-generation vaccines for rabies

Rabies is an enzootic viral disease widespread throughout the world. Although it is a vaccine-preventable disease, the annual number of human deaths caused by rabies is estimated to be 32,000 in Asia. Phylogenetic analysis based on sequence data of the partial N gene of rabies viruses in Asia has shown that the viruses are divided into five genogroups, distributed in Middle East, South Asia, South East Asia, Malay, and Arctic regions. The genetic relationships among these rabies viruses agree basically with the results of previous studies. Meanwhile, new types of vaccines are being developed by applying gene manipulation techniques to rabies virus in order to overcome the disadvantages of current vaccines. This article reviews the molecular epidemiology of rabies in Asia and progress made in the development of new-generation rabies vaccines with the goal of elimination or control of rabies in Asia.     

用于黄瓜白粉病抗性鉴定的InDel标记

根据黄瓜白粉病抗性主效基因/QTL的插入/缺失突变,将其设计成共显性的In Del分子标记。通过群体连锁分析,发现In Del-MLO1标记与黄瓜白粉病抗性主效基因共分离。应用该标记对24份来自世界各地且白粉病抗性已知的黄瓜材料进行抗性验证,21份材料的抗性表型与标记的带型一致,说明在黄瓜进化和驯化过程中,造成抗病表型的该插入/缺失突变发生普遍。因此,该In Del标记适合于大多数黄瓜材料的白粉病抗性鉴定和分子标记辅助育种,从而加快黄瓜白粉病抗病育种的进程。     

A 192bp allele at the <Emphasis Type="Italic">Xgwm261</Emphasis> locus is not always associated with the <Emphasis Type="Italic">Rht8</Emphasis> dwarfing gene in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The height-reducing gene Rht8 was introduced into Italian wheats by breeder Nazareno Strampelli from the Japanese landrace Akakomugi, and has been widely used in wheats adapted to southern and eastern European conditions. Following identification of a close linkage to Rht8, microsatellite marker Gwm261 has been used extensively to screen large numbers of diverse international germplasm. A 192bp allele at this locus has been taken as “diagnostic” for Rht8 and used to infer the international distribution of Rht8. In this paper, we report several instances of cultivars and mapping populations that vary for the presence of the 192bp allele at the Xgwm261 locus (Xgwm261 ₁₉₂ ), but with no associated reduction in height, suggesting a lack of association with Rht8. For instance, in the population derived from a cross between Sunco (Rht-B1b, Xgwm261 ₁₆₅ ) and Tasman (Rht-D1b, Xgwm261 ₁₉₂ ), there were significant height differences associated with the segregation of Rht-B1b and Rht-D1b, but no height differences between Xgwm261 genotypes. Similar results were obtained in a population derived from the cross between Molineux (Rht-B1b, Xgwm261 ₁₉₂ ) and Trident (Rht-D1b Xgwm261 ₂₀₈ ). In contrast, the cross between Trident and Chuanmai 18 (Xgwm261 ₁₉₂ ) gave significant height effects at both the Rht-D1 and Xgwm261 loci, with no epistatic interaction between loci. Chuanmai 18 is closely related to the Strampelli wheat Mara (ancestrally derived from Akakomugi) and is therefore likely to carry Rht8. The old Japanese cultivar Norin 10, used by Norman Borlaug to introduce Rht-B1b and Rht-D1b into Mexican wheats, also has a 192bp allele at the Xgwm261 locus, and the sequence of the amplified product is identical to that of Akakomugi. We suggest that the widespread use of Norin 10-derived germplasm during and after the Green Revolution introduced a second haplotype into international germplasm, in which Xgwm261 ₁₉₂ has no association with Rht8. Therefore, the presence of Xgwm261 ₁₉₂ is only indicative of Rht8 in wheat cultivars that have inherited this allele from Akakomugi or a Strampelli wheat ancestor.     

北沙柳研究进展

北沙柳属杨柳科柳属植物,具有萌蘖力强,耐旱、耐盐碱和抗风沙的特点,是中国西北地区固沙造林的主要树种之一,兼具生态效益、经济效益和社会效益。我们综述了国内外近年来北沙柳的相关研究成果包括生长繁殖、生理生态特征、与真菌共生作用、防风固沙、分子生物学及产业化开发与利用,并对未来发展前景做出展望,提出优良种质资源收集、分子定向育种和资源合理开发等建议,旨在为北沙柳的种质资源库管理、资源保护和合理开发应用提供科学依据。     

分子标记辅助选育抗稻白叶枯病的低温敏核不育系3178S

本研究以IRBB21为Xa21基因供体，籼型低温敏不育系399S为低温核不育系基因供体，采用杂交和回交方法，逐代用分子标记检测手段，导入广谱抗白叶枯病基因Xa21和低温敏核不育系基因，聚合双亲的有利性状，育成抗白叶枯病的籼型低温敏核不育系3178S，其抗性达到了IRBB21的抗性水平，且保持了399S稳定的育性和双亲的优良经济性状。     

Genetic variability in melon based on microsatellite variation

A set of 18 simple‐sequence repeat (SSR or microsatellite) markers was used to study genetic diversity in a collection of 27 melon (Cucumis melo L.) accessions, representing a broad range of wild and cultivated melons. The materials studied were highly polymorphic for SSRs and a total of 114 alleles were detected (average of 6.3 alleles per locus). Cluster analysis suggests the division of these accessions into two major groups, largely corresponding to the division of C. melo in the two subspecies agrestis and melo. The assignment of the accession to the subspecies was generally in agreement with published reports, except for those corresponding to the ‘dudaim’ and ‘chito’ cultivar groups, which, according to the observed SSR variability, should be included in subspecies agrestis. Based on cluster analysis, five groups of accessions were defined. The two most divergent groups include mainly accessions from the Mediterranean which form one group, and accessions from China, Japan, Korea and India forming the other. Both groups shared a low level of intra‐accession variation compared with the other groups, which suggests an erosion of their genetic variability because of drift and/or inbreeding. The remaining accessions, mainly from Central Africa and India, were more variable and may be an important source of genetic variation for melon breeding.