欧洲野生甘蓝的核质遗传多样性和群体遗传结构分析

为了解欧洲野生甘蓝遗传背景,以栽培甘蓝、甘蓝型油菜和白菜型油菜作对比,对引进的7个生态地理群体共80份野生甘蓝材料进行了核质遗传多样性和群体遗传结构分析。利用10对特异性SSR引物分析叶绿体基因组多样性,获得8个差异性标记,将参试94份材料划分为3类,即甘蓝（含栽培和野生甘蓝）、甘蓝型油菜和白菜型油菜;包括6种单倍型,其中野生甘蓝2个,甘蓝型油菜3个,白菜型油菜1个。利用6对SRAP引物对核基因组多样性进行分析,获得75个多态性标记;聚类及遗传结构分析表明7个野生甘蓝群体中,F、D、G三个群体聚为独立的亚类,E群体大部分单株归于G亚类。其它3个群体A、B、C则相互混杂在一起。野生甘蓝群体Nei＇s基因多样性指数（H）和Shannon’s指数（I）分别为0.301 3和0.461 1。分子方差分析（AMOVA）表明野生甘蓝以群体内变异为主,占80%;群体间变异仅占20%。结果显示引进的野生甘蓝群体核质遗传多样性丰富。     

烤烟种质资源遗传多样性和群体结构及亚群特异性研究

筛选多态性丰富的16对SRAP引物,对不同地理来源的276份烤烟资源的遗传变异进行分析,结果表明:16对SRAP引物共检测出611个等位位点,平均每对引物对38.19个,多态性较高;国外烤烟品种遗传多样性高于国内品种,贵州烤烟品种遗传多样性水平较低;NJ法聚类、PCA分析和STRUCTURE群体结构分析结果相互吻合,证明烤烟是与地理来源和亲缘关系密切相关的资源群,贵州烤烟资源形成了独立的组群,其遗传背景独特;各烤烟群体拥有独立的特有和特缺等位位点,群体间互补等位位点丰富,利用国外品种来拓宽国内烤烟品种的遗传基础最具潜力。     

《十字花科植物遗传与基因组学》由科学出版社出版

内容简介 十字花科植物包括有重要农作物（油菜、白菜、甘蓝、花菜等）、重要模式植物（拟南芥、荠菜等）和重要野生资源（如盐芥、高山南芥）。     

我国野生葡萄资源的保存现状及建议

葡萄野生种主要分布在东亚和北美，并且集中分布在中国和美国，使得中美两国拥有世界上90％以上的葡萄野生种。分类地位上的多样性是生物多样性的直接反映，所以中美两国是世界上两个最丰富的葡萄遗传资源的起源中心。美国在葡萄野生资源研究利用领域的工作开展的比较早，成效斐然。我国在此领域的研究开展的相对较晚，但也取得了令世界葡萄界瞩目的成就。但必须承认，在野生葡萄种植资源研究领域，我们现有的研究深度和广度愧对极为丰富的野生种质资源。     

强化管理,不断促进野生动植物保护管理迈上新台阶

我国是世界上生物多样性最丰富的国家之一,拥有众多水生野生动植物、作物野生近缘植物和草原野生动植物资源,现有动物10.45万种,是世界野生动植物种类最多的国家之一。本文就如何对野生动植物保护管理进行了研究,以此促进野生动植物保护工作再上新台阶。     

秃杉种质资源的遗传多样性研究

秃杉是第三纪热带植物区系的孑遗种,被列为国家一级保护树种,也是优良的造林树种.利用RAPD技术,通过11个多态随机引物对3个秃杉种源的遗传多样性进行了研究.结果表明,秃杉天然群体存在较丰富的遗传多样性,各位点平均基因多样度为0.4192,3个秃杉种源间的遗传多样性差异明显,19.5%的遗传变异存在于种源间.通过秃杉遗传多样性的研究,为有效保存和合理利用秃杉种质资源提供了理论依据.     

西藏野生油菜遗传多样性分析

利用10对AFLP引物及13对SSR引物,分析了43份来自西藏地区部分野生类型油菜种质的遗传多样性。10对AFLP引物共得到276条清晰的谱带,其中多态性带214条,多态性位点比率为77．5％,平均每对AFLP引物得到21．4条多态性带。13对SSR引物共扩增出57条带,其中多态性带51条,多态性位点比率为89．5％,说明西藏野生油菜遗传多样性丰富。通过对西藏野生类型油菜资源的遗传距离以及聚类分析,可将西藏野生类油菜分为两大类群,分别为白菜型和芥菜型野生油菜种质资源;两种分子标记适合揭示西藏野生油菜的遗传多样性。     

不同烟草群体间遗传多样性分析

利用SRAP标记对81份烟草种质进行遗传多样性分析,根据种性来源将81份种质材料分为黄花烟地方种质、普通烟草地方种质、选育种质以及引进种质四个群体.结果表明:(1)从160对引物组合中筛选出17对扩增带清晰、重复性和多态性好的引物用于81份烟草种质资源遗传多样性研究,共检测到163个位点,其中123个位点具有多态性,多态性比例为75.5%,平均每个引物检测到10个位点.遗传多样性指数(Nei's)和Shannon's指数分别为0.41和0.57,种质间遗传相似系数变异范围在0.11～0.99之间,说明我国烟草种质资源中存在着丰富的遗传变异. (2)四个群体遗传差异由大到小分别为:黄花烟地方种质>普通烟地方种质>引进种质>选育种质.(3)聚类分析可将81份种质材料划分为黄花烟草和普通烟草2大类群,烤烟、晒晾烟、白肋烟、雪茄烟以及香料烟五种栽培类型之间没有明确的界线;聚类分析和主坐标分析计算结果表明,黄花烟地方种质与其它三个群体的遗传距离较远,表明目前在我国烟草育种中对黄花烟的利用较少.引进种质和选育种质群体间遗传相似系数为0.99,说明目前我国烟草育种中较多利用引进种质,对具有丰富遗传变异的地方品种利用较少,育种亲本遗传基础狭隘.     

南方野生葡萄酵母菌资源研究进展

在南方野生葡萄人工大面积种植及各地大力发展葡萄酒产业的基础上,该文对南方地区野生葡萄酵母菌种生境的优势、酵母菌资源研究进展及酵母菌资源开发的研究方法进行了综述,发现南方地区的野生葡萄及葡萄酒产业具有独特的发展优势,且酵母菌资源丰富,但目前对其的开发及应用的程度有限,仍有较大的研究空间。为选育出适合酿造南方野生葡萄酒的优质野生酵母菌种、生产出具有地域性特色的葡萄酒产品以及为提高品牌的知名度提供了广阔的应用前景。     

南方野生葡萄酵母菌资源研究进展

在南方野生葡萄人工大面积种植及各地大力发展葡萄酒产业的基础上,该文对南方地区野生葡萄酵母菌种生境的优势、酵母菌资源研究进展及酵母菌资源开发的研究方法进行了综述,发现南方地区的野生葡萄及葡萄酒产业具有独特的发展优势,且酵母菌资源丰富,但目前对其的开发及应用的程度有限,仍有较大的研究空间。为选育出适合酿造南方野生葡萄酒的优质野生酵母菌种、生产出具有地域性特色的葡萄酒产品以及为提高品牌的知名度提供了广阔的应用前景。     

Effects of habitat fragmentation on genetic diversity and population differentiation of Liposcelis bostrychophila badonnel (Psocoptera: Liposcelididae) as revealed by ISSR markers

Liposcelis bostrychophila is a globally important stored product pest that is adapted to many habitats and is difficult to control due to insecticide resistance. We evaluated effects of habitat fragmentation on the genetic diversity and differentiation of L. bostrychophila populations. These genetic data were collected in Wuhu city, China using inter-simple sequence repeat (ISSR). A total of 108 discernible DNA fragments were detected, 107 were polymorphic and the percentage of polymorphic bands (PPB) was 99.1%. Shannon’s information index (I) and Nei’s gene diversity (He) from four populations were ordered (high to low) as herbstore > flourmill > bedroom > library. Population differentiation (Gst = 0.41) was average in these populations. Analysis of molecular variation (AMOVA) showed that variation existed mainly within populations (68.1%). At the same time, gene flow (Nm = 0.72) was interpreted to be moderate. Cluster analysis showed a small degree of genetic distance among different isolates and permitted grouping the isolates of L. bostrychophila into three distinct clusters. The study demonstrated clear genetic effects of habitat fragmentation on L. bostrychophila populations. Genetic diversity decreased and genetic differentiation increased between remnant populations when habitats were fragmented. Gene flow is not impeded by habitat fragmentation due to the impact of human activities. These findings are of great use for the prevention and control of this pest.     

黑龙江省土壤中大豆疫霉菌（Phytophthora sojae）的多样性

为探究不同类型土壤中大豆疫霉菌（Phytophthora sojae）的多样性,以分离自5种不同类型土壤的176株P.sojae为研究对象,利用基因推导法和AFLP分子标记技术进行多样性分析。结果表明,不同类型土壤中P.sojae无毒基因型、无毒基因种类、无毒基因组合和群体致病力均表现出差异性,其中黑土、白浆土和草甸土中的P.sojae无毒基因型、无毒基因种类和无毒基因组合多样性相对丰富,群体致病力中等偏弱;盐碱土中的P.sojae无毒基因型、无毒基因种类和无毒基因组合多样性丰富度较低,群体致病力相对较强;风沙土中没有分离到P.sojae。聚类分析表明,以0.76为阈值时,可将176株P.sojae划分为6个组,其中黑土和白浆土中的P.sojae呈现丰富的遗传多样性;草甸土和盐碱土中的P.sojae遗传多样性丰富度较低。综合分析表明,黑龙江省P.sojae群体无毒基因和遗传多样性丰富,并与土壤类型存在一定的相关性。     

Ex situ conservation of Holstein-Friesian cattle: comparing the Dutch, French, and US germplasm collections

Holstein-Friesian (HF) gene bank collections were established in France, the Netherlands, and the United States to conserve genetic diversity for this breed. Genetic diversity of HF collections within and between countries was assessed and compared with active male HF populations in each country by using pedigree data. Measures of genetic diversity such as probability of gene origin inbreeding and kinship were calculated. The cryobanks have captured substantial amounts of genetic diversity for the HF compared with the current populations. A substantial part of the US, French, and Dutch collections seems to be genetically similar. On the other hand, the US collection in particular represents an interesting reservoir of HF genes of the past. Gene banks can play an important role in conserving genetic diversity within livestock breeds over time, and may support industry in the future when needed.     

Biodiversity of Aspergillus section Flavi in the United States: A review

Fungi belonging to Aspergillus section Flavi are of great economic importance in the United States due to their ability to produce toxic and carcinogenic aflatoxins in agricultural commodities. Development of control strategies against A. flavus and A. parasiticus, the major aflatoxin-producing species, is dependent upon a basic understanding of their diversity in agricultural ecosystems. This review summarizes our current knowledge of species and population diversity in the United States in relation to morphology, mycotoxin production and genetic characters. The high genetic diversity in populations of aflatoxigenic fungi is a reflection of their versatile habits in nature, which include saprotrophic colonization of plant debris in soil and parasitism of seeds and grain. Genetic variation within populations may originate from a cryptic sexual state. The advent of intensive monoculture agriculture not only increases population size but also may introduce positive selective pressure for aflatoxin production due to its link with pathogenicity in crops. Important goals in population research are to determine how section Flavi diversity in agricultural ecosystems is changing and to measure the direction of this evolution.     

湖北省烟草赤星病长柄链格孢遗传多样性分析

为从分子水平揭示烟草长柄链格孢菌群体遗传学特性,本研究采用ISSR分子标记方法对十堰、襄阳、恩施、宜昌4个烟区的34株长柄链格孢菌进行了遗传多样性、遗传结构与分化以及种群间遗传变异分析;其中Nei’s多样性指数为0.1118~0.2061,Shnanon信息指数为0.1972~0.3177,表明长柄链格孢在不同地理种群间具有丰富的遗传多样性;遗传距离分析表明,十堰和襄阳,恩施与宜昌的菌株亲缘关系较近;居群每代迁移数（Nm）为3.2740 > 1,表明不同地理的种群间存在基因流动;利用NTSYS软件按UPGMA方法聚类分析,当相似性系数设定为0.79时,可将34个供试菌株分为4个类群,但菌株并没有按地理来源聚为不同的组,表明菌株之间的遗传多样性与其地理来源无明显的相关性。      

Nonparallel genome changes within subpopulations over time contributed to genetic diversity within the US Holstein population

Maintaining genetic variation in a population is important for long-term genetic gain. The existence of subpopulations within a breed helps maintain genetic variation and diversity. The 20,990 genotyped animals, representing the breeding animals in the year 2014, were identified as the sires of animals born after 2010 with at least 25 progenies, and females measured for type traits within the last 2 yr of data. K-means clustering with 5 clusters (C1, C2, C3, C4, and C5) was applied to the genomic relationship matrix based on 58,990 SNP markers to stratify the selected candidates into subpopulations. The general higher inbreeding resulting from within-cluster mating than across-cluster mating suggests the successful stratification into genetically different groups. The largest cluster (C4) contained animals that were less related to each animal within and across clusters. The average fixation index was 0.03, indicating that the populations were differentiated, and allele differences across the subpopulations were not due to drift alone. Starting with the selected candidates within each cluster, a family unit was identified by tracing back through the pedigree, identifying the genotyped ancestors, and assigning them to a pseudogeneration. Each of the 5 families (F1, F2, F3, F4, and F5) was traced back for 10 generations, allowing for changes in frequency of individual SNPs over time to be observed, which we call allele frequencies change. Alternative procedures were used to identify SNPs changing in a parallel or nonparallel way across families. For example, markers that have changed the most in the whole population, markers that have changed differently across families, and genes previously identified as those that have changed in allele frequency. The genomic trajectory taken by each family involves selective sweeps, polygenic changes, hitchhiking, and epistasis. The replicate frequency spectrum was used to measure the similarity of change across families and showed that populations have changed differently. The proportion of markers that reversed direction in allele frequency change varied from 0.00 to 0.02 if the rate of change was greater than 0.02 per generation, or from 0.14 to 0.24 if the rate of change was greater than 0.005 per generation within each family. Cluster-specific SNP effects for stature were estimated using only females and applied to obtain indirect genomic predictions for males. Reranking occurs depending on SNP effects used. Additive genetic correlations between clusters show possible differences in populations. Further research is required to determine how this knowledge can be applied to maintain diversity and optimize selection decisions in the future.     

高烟碱烤烟种质资源再鉴定及遗传多样性分析

低糖、高烟碱烟叶对降低卷烟焦油和提高卷烟劲头、香气至关重要,也是电子烟、口含烟等新型烟草制品的重要原料。为筛选高烟碱烤烟种质资源,对国家烟草种质资源中期库30份原标记为高烟碱的烤烟种质资源进行了化学成分再鉴定,筛选得到春雷一号、毕金一号、8100、I-35、广东黄（1）、辽烟十四号和NC729共7份高烟碱、低糖种质。同时基于农艺性状和化学成分等表型性状对30份高烟碱种质材料进行遗传多样性分析表明,供试种质数量性状的变异系数为12.79%~44.60%,遗传多样性指数为1.97~2.35,具有较高的遗传多样性。对表型数据进行主成分分析和聚类分析,将供试群体聚类成5个类群,每个类群的种质均具有显著的表型特征,其中类群Ⅰ、Ⅲ、Ⅳ可作为低糖、高烟碱品种的候选群体。     

四川雪茄烟叶种质资源的遗传多样性分析

为促进四川雪茄烟叶种质资源的开发和利用,通过农艺性状和SSR标记对20份雪茄烟叶种质资源进行遗传多样性分析。结果表明,供试种质资源具有较丰富的遗传多样性,各农艺性状的变异系数在6.59%~19.97%之间,遗传多样性指数在1.69~2.18之间,并聚类为4个类群,各类群间的农艺性状有显著差异。基于SSR标记技术的主成分分析和遗传结构分析把供试种质分为3个类群,聚类分析可把供试种质分为4个类群,为德雪1号、德雪2号、德雪3号和什烟一号的溯源研究提供线索。