我国地方鸡种保种群分子遗传多样性的检测

对国家家禽品种资源基因库中保存的10个地方鸡品种保种群进行了微卫星标记遗传多样性检测,计算各群体遗传参数,并用类平均法进行聚类分析。研究结果表明:30个微卫星标记在10个地方鸡品种保种群的平均杂合度在0.6189～0.6953之间,其中藏鸡最高,为0.6953;北京油鸡最低,为0.6189;平均多态信息含量均大于0.5,表现为高度多态性;10个鸡品种聚为4类:萧山鸡、茶花鸡、仙居鸡、白耳鸡聚为一类,丝毛乌骨鸡、北京油鸡、大骨鸡、固始鸡聚为一类,狼山鸡和藏鸡分别单独聚为一类。通过对我国地方鸡品种保种群的分子遗传多样性的检测,可以达到监测保种效果的目的。

发酵食品微生物多样性检验的初步解析

以传统自发酵黄豆酱为研究对象,采用OTU聚类分析、Alpha多样性分析等多种分子生物学技术对其微生物多样性展开了初步探究。结果表明,成熟自发酵黄豆酱中细菌种类多于真菌种类,曲霉菌属为黄豆酱样品中的优势菌群,变形菌门为黄豆酱发酵过程的优势菌种。此结果对于推动发酵食品的产业化生产,提升发酵食品质量具有重要意义。

ISSR及其在果树上的应用

ISSR是一种基于微卫星序列发展起来的新的分子标记,具有简便、稳定、DNA多态性高等优点。ISSR标记呈孟德尔式遗传,大部分ISSR标记为显性标记。综合有关文献就ISSR的原理、操作及其在果树种质鉴定、遗传多样性检测、亲缘关系分析和遗传图谱构建等方面的应用和进展进行简要的阐述。

RAPD及其在果树上的应用

就RAPD的特点、操作及其在果树品种鉴定、遗传多样性检测、系谱解析和遗传图谱构建等方面的应用和进展进行了简要的阐述。

ISSR分子标记在入侵植物研究中的应用

外来生物入侵是对全球生物多样性最为严重的威胁之一,对经济安全、生态安全、社会安全、国际利益和国际贸易都具有重要影响.入侵种群的分子标记分析是外来入侵生物研究的重要途径.其中,简单序列重复区间标记(inter-simple sequence repeat,ISSR)是一种基于微卫星序列发展起来的新型分子标记,具有简便、快捷、结果稳定和DNA多态性高等优点.本文系统地介绍了ISSR分子标记的原理、技术特征及其实验操作,并简要地阐述了ISSR分子标记在外来入侵植物的群体遗传结构分析、遗传多样性检测、入侵来源推测、入侵植物的分布模式及其亲缘关系分析、入侵植物的繁育特性检测等方面的应用及其研究进展.

土壤真菌研究进展

本文简要概述了土壤真菌的类群,多样性检测,群落生态学以及其在生态系统中的作用,并简要对分离和计数的方法进行了介绍。

AFLP技术的改进及其在果树上的应用

AFLP分子标记技术是一种基于PCR的高分辨DNA指纹分析方法,和其它标记技术相比,它具有相对简便、快速、可靠、便宜的优点。综合有关文献资料就AFLP的原理、试验技术方面的改进及其在果树遗传多样性检测、种质资源鉴定、亲缘关系分析和遗传图谱的构建等方面的应用和进展进行阐述。

随机扩增多态DNA技术在野生动物研究中的应用

随机扩增多态ＤＮＡ（ＲＡＰＤ）是十分有效的遗传标，具有简单、快速、经济的优点。在野生动物研究 中．主要用于物种鉴定、遗传多样性分析、系统进化和分类研究、亲权鉴定、性别鉴定、基因渗入的检测及基因定位 和分子连锁图谱构建等领域。ＲＡＰＤ技术在野生动物领域的广泛应用．必将促进野生动物保护事业的发展。

柿属植物DNA分子标记研究进展

经过近20 a的发展,DNA分子标记已经在柿属植物中得到较为广泛的应用。以基于核酸杂交、PCR、逆转座子及胞质基因组等不同类型的分子标记技术为线索,从种质鉴定、遗传多样性检测、亲缘关系重建,以及特殊种质的起源和重要经济性状的连锁分析等方面,扼要总结了DNA分子标记在柿属植物上的应用研究进展。同时对该领域的研究前景和尚需解决的问题进行了讨论,认为柿属植物DNA分子标记的开发应侧重于功能型分子标记、DNA条形码片段和品种标准DNA指纹图谱。

The loss of genetic diversity during captive breeding of the endangered sculpin, Trachidermus fasciatus, based on ISSR markers: implications for its conservation

Abstract Inter-simple sequence repeat （ISSR） markers were used to determine the genetic variation and genetic differentiation of cultured and wild populations of Trachidermus fasciatus, an endangered catadromous fish species in China. Six selected primers were used to amplify DNA samples from 85 individuals, and 353 loci were detected. Relatively low genetic diversity was detected in the cultured population （the percentage of polymorphic loci PPL=73.80%, Nei＇s gene diversity h--0.178 2, Shannon information index I=0.276 9）. However, the genetic diversity at the species level was relatively high （PPL-91.78%; h = 0.258 3, I= 0.398 6）. The UPGMA tree grouped together the genotypes almost according to their cultured and wild origin, showing distinct differences in genetic structure between wild and cultured populations. The pairwise F^t values confirmed significant genetic differentiation between wild and cultured samples. The cultivated population seems to be low in genetic diversity as a result of detrimental genetic effects in the captive population. The results suggest that ISSR markers are effective for rapid assessment of the degree of diversity of a population, thus giving important topical information relevant to preserving endangered species.

High genetic diversity in gametophyte clones of Undaria pinnatifida from Vladivostok, Dalian and Qingdao revealed using microsatellite analysis

Breeding practice for Undaria pinnatifida （Harvey） Suringar requires the screening of a large number of offspring from gametophyte crossings to obtain an elite variety for large-scale cultivation. To better understand the genetic relationships of different gametophyte cultures isolated from different sources, 20 microsatellite loci were screened and 53 gametophyte clone cultures analyzed for U. pinnatijqda isolated from wild sporophytes in Vladivostok, Russia and from cultivated sporophytes from Dalian and Qingdao, China. One locus was abandoned because of poor amplification. At the sex-linked locus of Up-AC-2AS, 3 alleles were detected in 25 female gametophyte clones, with sizes ranging from 307 to 316 bp. At other loci, 3 to 7 alleles were detected with an average of 4.5 alleles per locus. The average number of alleles at each locus was 1.3 and 3.7 for Russian and Chinese gametophyte clones, respectively. The average gene diversity for Russian, Chinese, and for the combined total of gametophyte clones was 0.1, 0.4, and 0.5, respectively. Russian gametophyte clones had unique alleles at 7 out of the 19 loci. In cluster analysis, Russian and Chinese gametophyte clones were separated into two different groups according to genetic distance. Overall, high genetic diversity was detected in gametophyte clones isolated from the two countries. These gametophyte cultures were believed to be appropriate parental materials for conducting breeding programs in the future.

Inbreeding and genetic diversity analysis in a hatchery release population and clones of Rhopilema esculentum based on microsatellite markers

Ten microsatellite markers were used to analyze the levels of genetic diversity and inbreeding in a hatchery release population of Rhopilema esculentum Kishinouye （Scypbozoa： Rhizostomatidae）. A total of 85 alleles were detected in 600 individuals. Within-population levels of observed （Ho） and expected （He） heterozygosity ranged from 0.152 to 0.839 （mean=0.464） and from 0.235 to 0.821 （mean=0.618）, respectively. The polymorphism information content （PIC） of each marker ranged from 0.207 to 0.795 with an average of 0.580, indicating that the hatchery population maintained a high level of genetic diversity. Inbreeding levels were estimated in the hatchery population and the inbreeding coefficient was 0.203. This result revealed that a certain level of inbreeding occurred within the population. Meanwhile, we also determined genetic diversity at the clone level. Several polyps from the same scyphistomae were genotyped at the ten microsatellite loci and there was virtually no difference in their genotypes. Furthermore, we calculated the probabilities of exclusion. When both parents were known, the average exclusion probability often loci was 99.99%. Our data suggest that the ten microsatellite markers can not only be used to analyze the identity of individuals but they can also be applied to parentage identification. Our research provides a theoretical basis and technical support for genetic diversity detection and reasonable selection of R. esculentum hatchery populations. These findings support the use of releasing studies and conservation of R. esculentum germplasm resources.

Genetic Diversity of Italian Ryegrass Diploid Cultivars, Revealed by Electrophoretically Detected Genotypes in Phosphoglucose Isomerase （PGI）

Nine diploid cultivars of Italian ryegrass （Lolium multiflorum Lain.） from France （Fortyl, Vertyl and Jericho）, Germany （Ligrande）, United Kingdom （Aber Epic and Aber Mario）, Denmark （Cordelia）, Netherlands （Alamo） and Poland （Tur） were tested with horizontal gel electrophoresis according to one locus （with four alleles） of the PGI enzyme system. One of them, named P4 is typical for the species, therefore can serve as a good marker for hybrids identification. Each cultivar was characterized by frequencies of different phenotypes. They were highly polymorphic （Pg = 0.58 - 0.78） and showed differences in heterozygosity level. The variability within populations （GST = 0.055） was higher than among populations （DST = 0.032）.

AFLP analysis of genetic variation among three natural populations of horseshoe crab Tachypleus tridentatus along Chinese coast

The AFLP(amplified fragment length polymorphism) technique was used to analyze and compare the genetic diversity of Tachypleus tridentatus from three south-eastern coastal sites of China(Pingtan,Hong Kong and Beihai).Eight pairs of primers generated 361 loci,including 285 polymorphic loci.The ratio of polymorphic loci was 96.97%.Nei's genetic diversity index was 0.420 8 and the Shannon information index was 0.607 5,both of which were higher than that reported for many other arthropods.These results show that the genetic diversity detected was mainly caused by individual differences within a population.Genetic distance showed that the rational division of the three geographic populations of T.tridentatus along the south-eastern coast of China was not significant,in which the genetic distance was not proportional to the geographic distance.All three horseshoe crab populations may belong to a large group,and had a high degree of genetic similarity.The high level of genetic diversity obtained from the present AFLP analysis may be due to the large effective population size of the species in Chinese waters.

Geochip-based analysis of microbial functional genes diversity in rutile bio-desilication reactor

Biological desilication process is an effective way to remove silicate from rutile so that high purity rutile could be obtained. However, little is known about the molecular mechanism of this process. In this work, a newly developed rutile bio-desilication reactor was applied to enrich rutile from rough rutile concentrate obtained from Nanzhao rutile mine and a comprehensive high through-put functional gene array(Geo Chip 4.0) was used to analyze the functional gene diversity, structure and metabolic potential of microbial communities in the biological desilication reactor. The results show that TiO2 grade of the rutile concentrate could increase from 78.21% to above 90% and the recovery rate could reach to 96% or more in 8-12 d. The results also show that almost all the key functional genes involved in the geochemical cycling process, totally 4324 and 4983 functional microorganism genes, are detected in the liquid and ore surface, respectively. There are totally 712 and 831 functional genes involved in nitrogen cycling for liquid and ore surface samples, respectively. The relative abundance of functional genes involved in the phosphorus and sulfur cycling is higher in the ore surface than liquid. These results indicate that nitrogen, phosphorus and sulfur cycling are also present in the desiliconization process of rutile. Acetogenesis genes are detected in the liquid and ore surface, which indicates that the desiliconizing process mainly depends on the function of acetic acid and other organic acids. Four silicon transporting genes are also detected in the sample, which proves that the bacteria have the potential to transfer silicon in the molecule level. It is shown that bio-desilication is an effective and environmental-friendly way for enrichment of rough rutile concentrate and presents an overview of functional diversity and structure of desilication microbial communities, which also provides insights into our understanding of metabolic potential in biological desilication reactor ecosystems.

2016车度华耐园艺科技奖——华中农业大学“柿研究团队”

华中农业大学罗正荣老师带领“柿研究团队”历时20余年对原产中国中部大别山区的中国甜柿基因资源进行系统的调查、收集、保存，以及遗传多样性检测、遗传稳定性鉴定和经济现状评价研究的基础上，基本阐明其遗传多样性起源和演化途径；初步揭示其自然脱涩特点，筛选出与自然脱涩有关的功能基因并构建其分子调控网络。

Limited gene flow and partial isolation phylogeography of Himalayan snowcock Tetraogallus himalayensis based on part mitochondrial D-loop sequences

Himalayan snowcock Tetraogallus himalayensis are distributed in alpine and subalpine areas in China. We used mi- tochondrial DNA control-region data to investigate the origin and past demographic change in sixty-seven Himalayan snowcock T. himalayensis. The fragments of 1155 nucleotides from the control region of mitochondrial DNA were sequenced, and 57 poly- morphic positions defined 37 haplotypes. A high level of genetic diversity was detected in all populations sampled and may be associated isolation of the mountains and habitat fragmentation and deterioration from Quaternary glaciations. In the phylogenetic tree, all haplotypes grouped into four groups： clade A （Kunlun Mountains clade）, clade B （Northern Qinghai-Tibetan Plateau clade）, clade C （Tianshan Mountains clade） and clade D （Kalakunlun Mountains clade）. We found a low level of gene flow and significant genetic differentiation among all populations. Based on divergence time we suggest that the divergence of Himalayan snowcock occurred in the middle Pleistocene inter-glaciation, and expansion occurred in the glaciation. Analysis of mtDNA D-loop sequences confirmed demographic population expansion, as did our non-significant mismatch distribution analysis. In conclusion, limited gene flow and a pattern of partial isolation phylogeographic was found in geographic populations of T. hima- layansis based on the analysis on mtDNA D-loop sequences [Current Zoology 57 （6）： 758-767, 2011].

Effect of initial phase diversity on signal detection in excitable systems

Undoubtedly, the sensory organs of biological systems have been evolved to accurately detect and locate the external stimuli, even if they are very weak. However, the mechanism underlying this ability is still not fully understood. Previously, it had been shown that stochastic resonance may be a good candidate to explain this ability, by which the response of a system to an external signal is amplified by the presence of noise. Recently, it is pointed out that the initial phase diversity in external signals can be also served as a simple and feasible mechanism for weak signal detection or amplification in excitable neurons. We here make a brief review on this progress. We will show that there are two kinds of effects of initial phase diversity: one is the phase disorder, i.e., the initial phases are different and static, and the other is the phase noise, i.e., the initial phases are time-varying like noise. Both cases show that initial phase diversity in subthreshold periodic signals can indeed play a constructive role in the emergence of sustained spiking activity. As initial phase diversity can mimic different arrival times from source signal to sensory organs, these findings may provide a cue for understanding the hunting behaviors of some biological systems.