蒙古冰草遗传多样性的RAPD分析

采用RAPD技术对蒙古冰草（Agropyron mongolicum Keng)6个天然居群和2个栽培品种（系）的45个个体进行了遗传多样性检测。17个引物共检测到101个位点,其中多态位点81个,占80.2%,相对于其它小麦族植物,显示出了较高的遗传多样性,多样性指数（DC）分析的结果表明,遗传多样性在居群内和居群间的分布存在不均衡现象,但总体来看,居群内的遗传变异高于居群间,这是由蒙古冰草异花,风媒传粉的外繁育系统所决定的,在天然居群与栽培品种（系）间,前者的DC值为0.250,后者的DC值为0.181,而且前者的平均遗传距离（0.290)也高于后者（0.213),表明天然居群间的遗传分化大于栽培品种（系）,这与天然居群间环境的异质性密切相关,同时也反映了栽培品种（系）间较近的亲缘关系,UPG-MA聚类分析的结果表明,8个居群基本上可被分为与其生境特点及生长条件相适应的3个类群,反映了自然选择及人工选择对居群间遗传分化的巨大影响。     

Isozyme variation among teak (Tectona grandis L.f.) provenances

Fourteen enzyme systems were analysed in leaf parenchyma of nine native and introduced populations of teak. These enzyme systems were encoded by 20 putative loci of which 18 were polymorphic. Populations showed a general lack of heterozygosity (average F_IS = 0.11). On average over the 18 polymorphic loci, the genetic differentiation among provenances varied according to the estimator: 0.09 for G_ST, 0.12 for F_ST and 0.19 for . The cluster analysis showed two main gene pools, the first consisted of the Indian provenances and the second of African, Indonesian and Thai provenances. Genetic distances among populations of the same group were similar, and lower than the genetic distances between populations from different groups. The factorial analysis on genotypes of seedlings also showed the same geographic differentiation into two major groups. The possible natural distribution of teak in Java is discussed.     

人工与自然恢复条件下地被层优势种大羽藓的遗传多样性比较

基于随机扩增多态性DNA(RAPD)方法比较了川西米亚罗地区3个人工云杉林样地和3个天然次生林样地大羽藓(Thuidium cym bifolium)种群的遗传多样性及分化程度。人工林种群的平均多态位点百分比(PPL)为12.7%,Ne i’s基因多样性(HE)为0.042,Shannon’s信息指数(S)为0.064,种群内遗传一致度(I)为0.952;天然次生林种群则依次为10.0%、0.027、0.043和0.960。人工林种群和天然次生林种群Gst分别为0.592和0.702,Fst分别为0.639和0.695;结合UPGMA聚类和PCA分析,发现种群间的基因交流极少。单因素方差分析显示,人工林下大羽藓种群的遗传多样性水平显著高于天然次生林下种群(p<0.05),表明在皆伐迹地上通过人工造林能有效地促进林下物种遗传多样性的恢复。     

Genetic diversity within and among 11 juvenile populations of green alder (Alnus crispa) in Canada

Germinated seeds from 11 populations of green alder [ Alnus crispa (Ait.) Pursh] sampled in four Canadian provinces were analysed for electrophoretically demonstrable diversity of 10 enzymes encoded by 15 structural loci. Of these, nine were polymorphic, and on average, 52% of the loci per population were polymorphic. Assuming a diploid model of expression, average level of expected heterozygosity was 0.11 with nearly all populations in Hardy-Weinberg equilibrium for the set of polymorphic loci analysed. No significant inbreeding and associated subpopulation structuring were noted. Rates of gene flow appeared high within and among populations. Although little divergence was observed among populations, genetic and geographical distances between populations were related. Discriminant and cluster analyses revealed a pattern of genetic variation associated with geography. Populations from northern Quebec were poorly differentiated, whereas western populations from Alberta exhibited a larger degree of genetic differentiation. Introgresive hybridization with the sympatric species Alnus sinuata (Regel) Rydberg and partial isolation in the West are suggested as an explanation for this larger differentiation. The occurrence and significance of rare alleles is discussed in relation to the importance of geographical distance in the process of population differentiation in this species.     

巴东木莲等位酶的遗传多样性

采用超薄平板聚丙烯酰胺等电聚焦技术对中国特有濒危植物巴东木莲(Manglietia patungensis Hu)的遗传多样性进行了初步的分析。通过对8个酶系统18个酶位点的检测,结果表明,巴东木莲具有较高的遗传多样性。种水平多态位点的百分数(Ps)为66．7,平均预期杂合度(He)为0．178。高于多年生木本植物的平均水平。居群间分化系数为0．107,说明巴东木莲的遗传变异的89．3％来自于居群内。     

Analysis of Species Relationship Among Seven Small Millets Using Molecular Markers

Genomic DNA of twenty four accessions belonging to seven small millet species were analyzed for RAPD, RFLP and AFLP profiles for a comprehensive understanding of the level of genetic diversity within the species and relationships between them. Thirty random primers generated a total of 115 amplification products of which 70 were polymorphic across all species.Twenty-five probe enzyme combinations were used for RFLP analysis that revealed 87 loci of which 62 were polymorphic across the species.AFLP analysis was done at inter-specific level using 12 primer combinations.This generated a total of 869 fragments of which 821 were polymorphic across the species analyzed. Species-specific AFLP profiles were obtained in 10 of the 12 primer combinations tested. It was noticed that the intra-specific variability in all the RAPD and RFLP marker systems was negligible. Species-specific polymorphic loci were observed for all the marker systems.The results are discussed in relation to the genetic relationship among the seven species analyzed.     

DNA-identification of rice varieties (<Emphasis Type="Italic">Oriza sativa</Emphasis> L.) of Ukrainian breeding

Genetic diversity assessment in 11 rice varieties of the Rice Research Institute’ (Ukrainian Academy of Agrarian Sciences) and also differentiation and identification of 11 rice varieties were conducted by the analysis of 25 SSR-markers. Based on the allele composition of 12 polymorphic microsatellite loci, genetic formulas of examined varieties were developed. UPGMA cluster analysis, with the use of the genetic distances method, allowed for the calculation of differentiation of rice varieties and showed that the Ukrainian rice varieties are genetically similar. As a whole, the use of the SSR-markers was revealed as an effective tool for the assessment of genetic diversity and genotyping within rice varieties of Ukrainian breeding.     

Differentiation and phylogenetic relationship among different cultivars of asparagus bean (Vigna unguiculata ssp. sesquipedalis) assessed using ISSR markers

Asparagus bean, one of the three subspecies of Vigna unguiculata, has a long cultivation history in China. The genetic diversity was analyzed based on the 66 landraces and cultivars cultivated in China by using ISSR molecular markers, with which 192 amplification loci were obtained 32.3% of them being polymorphic. The genetic differentiation analysis revealed a very high genetic diversity in the Chinese landraces, which confirmed that China is the secondary origin centre of the asparagus bean. The commercial cultivars bred in China were genetically highly homogenous, suggesting that the breeding process has resulted in disappearance of some of the genetic variation. A cluster analysis at 0.17 of Nei genetic distance divided the 66 landraces and cultivars into 9 groups. Their clustering pattern basically matches the phylogeny of those cultivars, and also corresponds to their geographical origin and morphological traits.     

中国落叶松-杨栅锈菌遗传多样性研究

采用SSR分子标记技术对采自全国19个地区、不同年份的落叶松-杨栅锈菌Melampsora larici-populina（简称MLP）36个单孢子堆菌系的遗传多样性和种群遗传结构进行了研究。用5对SSR多态性引物共检测到62个观察等位基因（Na）,有效等位基因数（Ne）为5.42–9.82,平均有效等位基因数为7.05。供试MLP样本在5个SSR位点上的多态性信息量（PIC）变化范围为0.64–0.89,平均值0.79。平均观察杂合度（Ho）、平均期望杂合度（He）分别为0.36和0.86,不同位点的S     

Genetic analysis of fish genomes and populations: allozyme variation within and among Atlantic salmon from Downeast rivers of Maine

Analysis of genetic variation within and among samples of naturally produced Atlantic salmon ( n  = 372) from 7 Maine (U.S.A.) and one Canadian river were conducted based on 54 allozyme loci. Eight of the 54 loci proved polymorphic, and estimated heterozygosities ( H _S) based on all loci ranged from 0·012 to 0·026 (mean = 0·021, s . e . = 0·002). Only one of 56 tests revealed genotypic proportions that deviated significantly from Hardy–Weinberg expectations. Genetic distances ( D ) between samples ranged from 0·002 to 0·022. No obvious association existed between genetic and geographic distances. Cluster analysis of genetic distances revealed the Dennys River sample as the most differentiated when all samples were included in the analysis, though bootstrap support of the cluster analysis was generally weak. G ‐tests revealed significant differences in allele frequencies among samples at five of the polymorphic loci, and the G ‐value summed over all loci also indicated significant differences among samples. F _ST values indicated that 3·4% of the total genetic diversity was due to variability among samples, while 96·6% was due to variability within samples. These results indicate that the Atlantic salmon analyzed in this study had levels of genetic variability and differentiation among samples comparable to native populations from other areas collected across a similar geographic range.     

Numerical analysis of allozyme variation inCucurbita pepo

Cucurbita pepo, represented by cultivated forms of squash, pumpkins, and ornamental gourds, is a morphologically diverse species. Although several classifications of the cultivars have been proposed, none has been fully accepted. In an attempt to clarify the systematics of theC. pepo cultivars, allozyme variation was assayed. Twelve loci representing 6 enzyme systems (GOT, IDH, MDH, PER, PGI, and PGM) were screened. Seven of the loci were polymorphic. Electrophoretic data were collected for 50 accessions representing 14 commercial cultivars and a landrace from Mexico. Statistical analyses of the allozyme data revealed a biochemical basis for characterizing cultivars that agrees with morphology. Principal component analysis and cluster analysis revealed a major subdivision within the species above the level of cultivars. Genetic identities among groups of cultivars were much lower than those usually found among conspecific populations for outcrossing plants, possibly reflecting the influences of populational subdivision, drift, and selection particular toC. pepo.     

欧洲中部刺槐种源群体等位酶变异研究

从欧洲中部及美国收集了18个刺槐种源种子,以2年生苗木为材料,采用水平切片淀粉凝胶电泳和聚丙烯酰胺凝胶电泳对11个酶系统进行了检测,共发现20个酶位点,其中14个为多态位点,多态性位点百分数为70％。在参加计算的7个酶系统的12个多态性位点中,平均每个位点的等位基因数(A)和平均每位点等位基因有效数(Ae)为2.733和1．794,平均每个位点的实际杂合度(Ho)和预期杂合度(He)为0．368和0．400,固定指数(F)为0．080,绝大多数位点固定指数为正值。各基因位点遗传参数与12个位点平均值进行相关分析表明,Fe-6和Lap-a的大部分群体遗传参数(A、Ae、Ho、He等)与平均值存在紧密的相关关系,其他位点各项遗传参数和总平均值相关不明显,这些位点的重要性可能比相关性较好的位点更大。德国8个种源群体间遗传距离变化在0．09-0．26之间,来自匈牙利的6个种源之间遗传距离很小,绝大部分均在0．11以下;德国的8个种源与匈牙利和斯洛伐克的8个种源之间的遗传距离变化在0．09-0．24之间;来自美国的2个种源,与欧洲的种源间的遗传距离在0．09-0．23之间,这一距离没有超出欧洲种源之间的差异。匈牙利和斯洛伐克的8个种源群体的各项遗传参数均高于德国种源,表明这两个国家的遗传多样性水平较高。同时来自这两个国家的种源群体间变异系数变化在2．92％-9．97％,说明群体之间的遗传差别很小。德国的8个种源群体各项遗传参数相对较低,但群体间变异系数较高,群体间遗传差别较大。以各个国家为群体单位,4个群体间各项遗传参数的变异均较小,变异系数变化在3．861％-5．139％,表明刺槐种源间地理变异模式不明显。     

雌雄异株稀有植物伞花木(Eurycorymbus caraleriei)自然居群的等位酶遗传多样性研究

伞花木（Eurycorymbus caraleriei）为中国特有的第三纪孑遗单种属植物,雌雄异株。采用超薄平板微型聚丙烯酰胺等电聚焦电泳方法对其5个自然居群和1个人工迁地保护居群的等位酶变异进行了初步研究。对7个酶系统中14个位点的等位酶居群遗传多样性及遗传结构分析结果表明：伞花木具有较高水平的遗传多样性,其每位点平均等位基因数A=1．6,平均多态位点比率P=42．9％,平均预期遗传杂合度Hr=0．216;各居群的遗传多样性无显著性差异,但都表现为严重偏离Hardy-Weinberg平衡的杂合子过量;其遗传变异主要发生在居群内（93．1％）,居群间分化较小（Gst=0．069）,居群问遗传一致度较高（I=0．965～1．000）。推断这可能是由于其古老孑遗性、雌雄异株、混和传粉方式的生物学特性以及其长寿命的生活史等原因所导致;同时,居群间的较高基因流（Nm=3．128）也可能起到很大的作用。还使用UPGMA聚类方法推断了武汉植物园迁地保护的野外居群来源,在对迁地保护居群的评价中发现迁地保护居群仅保存了该物种基因型多样性的16％,在此基础上提出了今后进一步的保育策略。     

Genetic diversity and differentiation in natural and reintroduced populations of Bencomia exstipulata and comparisons with B. caudata (Rosaceae) in the Canary Islands: an analysis using microsatellites

Variation at five polymorphic microsatellite loci was used to investigate genetic diversity and differentiation of two tetraploid Canarian endemics, Bencomia exstipulata and B. caudata. Data were analysed and are discussed in terms of tetrasomic (autotetraploid) and disomic (allotetraploid) inheritance. In both cases, genetic diversity values were similar to those described in other tetraploid plant species. High genetic differentiation between the only two described natural populations of B. exstipulata was detected (F_ST = 0.411). Bayesian cluster analysis revealed a geographical structure with distinct genetic groups from each island. High genetic differentiation and low genetic diversity of the B. exstipulata population from Tenerife suggest a recent population bottleneck, perhaps caused by the most recent major volcanic eruption, for this natural locality. This may be heightened by possible inbreeding depression and the monoecy of these species. Polymorphic microsatellite loci were also tested across all species in the Bencomia alliance. These reliably amplified the target sequence, suggesting a high degree of conservation of the sequences flanking the microsatellites. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 429–441.     

Genetic variation of chloroplast and nuclear markers in natural populations of hazelnut (Corylus avellana L.) in Germany

Corylus avellana L. (hazel) is a long-lived, monoecious and wind-pollinated shrub species, widespread all over Europe. In Germany, hazel is intensively traded and planted, and thus is of central interest from a nature conservancy point of view. To assess the within- and between-population differentiation of hazel, 20 natural populations (18 from Germany, one from Italy and one from Hungary) were investigated genetically. Seven isozyme systems comprising 11 gene loci were analysed in up to 100 samples (average 92.6) per population, amplified fragment length polymorphisms (AFLP) were analysed in up to 50 samples (average 47.4) and nine cpDNA-SSR markers were assessed in 20 samples per population. Results for overall isozyme variability with Na 2.46 alleles per locus, allelic diversity (Ne) 1.39, expected heterozygosity He 21 % and 79 % polymorphic loci were in accordance with the findings of previous studies. The respective values for AFLPs were lower, but both marker systems revealed the same level of about 3.5 % differentiation between populations. For cpSSR only the Italian sample showed within-population variation and the two haplotypes were completely differentiated from all other populations expressing a unique genetic structure with one single haplotype. Among the three marker systems AFLPs showed the best ability to differentiate between populations. While only one isozyme locus revealed significant differentiation, 41 AFLP loci showed highly significant differentiation between all populations, but 26 loci when only German populations were considered. Consequently geographic differentiation analyses focused mainly on molecular markers. Mantel tests showed significant correlations between genetic and geographic distance, but in the unweighted pair-group method with arithmetic mean analyses, adjacent populations did not always form clusters. While chloroplast markers were able to clearly distinguish only the Hungarian population, the nuclear markers revealed clear spatial genetic structures. The correlations between geographic and genetic distance was high for AFLPs. The correlograms illustrate this effect for all populations as well as for the German populations.     

Genetic Diversity of Protein Markers in Sheep Populations from Ukraine

Based on polymorphism of genes for antigen factors of six blood-group systems and four blood protein loci, genetic structure and the main variation parameters were studied in three sheep breeds and three sheep breed types constituting the basis of purebred sheep resources in Ukraine. Specific features of the distribution of genotypes and alleles of polymorphic loci were determined in each of the studied sheep groups depending on their origin and production type. The molecular–genetic markers used in the analysis of the genetic relationships between the sheep breeds and breed types were shown to objectively reflect their breeding history and evolution. Integrally, each of the studied gene pools had a specific profile of gene frequencies reflecting breeding specificity, breed history, and genetic differentiation of breeds.     

Host-based genetic differentiation in the aphid Aphis gossypii Glover, evidenced from RAPD fingerprints

Samples of the aphid Aphis gossypii (Glover) were collected from different host plants at 18 locations in southern France, La Réunion, Portugal and Laos. RAPD (random amplified polymorphic DNA) patterns of the 480 aphids were obtained using three random primers. A large number of RAPD bands were shared by all aphids of the 18 populations, but some RAPD bands appeared to be population specific. Over all aphids, a total of 37 polymorphic bands were identified and defined 142 RAPD phenotypes. A cluster analysis based on genetic distance revealed that the 18 aphid populations were divided into two groups, depending on whether they were collected on a cucurbit host plant. An analysis of molecular variance ( AMOVA ) was also performed and confirmed the differentiation into two groups. Several RAPD bands that were obtained using random primer A11 could be considered as diagnostic loci as they were fixed in populations collected on cucurbits and were always absent in those collected on noncucurbit host plants. These results represent the first evidence for genetic structuring within the species A. gossypii , according to host-plant type.     

Genogeographic variability and genetic differentiation of the root vole (Microtus oeconomus Pallas, 1776, Cricetidae, Rodentia) from the Kuril Islands

Electrophoretic analysis of 12 enzyme systems and 3 nonenzyme proteins (in all, 24 interpretable loci) was carried out for Microtus oeconomus from ten Kuril islands, Kamchatka Peninsula, and the vicinity of the city of Magadan. Gene geographic variation was examined and the coefficients of genetic variation and differentiation were estimated. The inter-population allozyme differentiation was low (DNEI, 1972 not higher than 0.053) and caused by variation in the allele frequencies of polymorphic loci. The greatest genetic distances were found between the populations belonging to different subspecies. Allozyme differentiation of Far Eastern M. oeconomus and M. fortis are discussed in relation to the data on the age of the island isolation and paleontological records. Karyological analysis (G-, C-, and NOR-banding) demonstrated the absence of differences between M. oeconomus from Kamchatka and the vicinity of Magadan.     

中国石榴栽培群体遗传多样性的荧光AFLP分析

以中国山东、安徽、陕西、河南、云南和新疆6个栽培石榴群体的85个品种类型为试材,利用荧光标记AFLP对中国石榴群体遗传多样性进行了研究。结果表明：8对引物组合在种级水平扩增的多态性位点数范围从135～185个不等,平均为158.25个,多态位点百分比范围为62.5%～86.11%,平均为73.26%,说明中国石榴品种遗传多样性较为丰富;石榴品种种级水平遗传多样性大于群体水平,6个群体的遗传多样性依次为河南群体〉新疆群体〉陕西群体〉安徽群体〉山东群体〉云南群体,并且具有显著性差异;群体间的遗传分化系数GST为0.2018,说明石榴遗传变异主要存在群体内,群体间的遗传变异占总变异的20.18%,根据基因分化系数,测得的基因流Nm为1.9027,说明中国石榴群体间存在适当的基因交流;UPGMA聚类分析结果表明,同一群体的大部分品种都聚在一起,但同时存在部分基因交流。所有遗传参数表明,中国石榴栽培品种遗传多样性较为丰富,其中河南群体遗传多样性显著高于其他群体,在中国石榴品种选育中具有更为广阔的应用前景。     

Analysis of the genetic diversity of garlic (Allium sativum L.) by simple sequence repeat and inter simple sequence repeat analysis and agro-morphological traits

The genetic diversity of 39 garlic accessions was investigated using eight simple sequence repeat (SSR) primer combinations and 17 inter-simple sequence repeat (ISSR) primer combinations. A total of 109 polymorphic loci were detected among these accessions, with an average of 4.63 polymorphic loci per SSR primer combination and 4.29 polymorphic loci per ISSR primer combination. The mean effective number of alleles, the mean Nei's genetic diversity, and the mean Shannon's information index for SSR were 1.4799, 0.2870, and 0.4378, respectively; and those for ISSR were 1.4847, 0.2898 and 0.4415, respectively. Cluster analysis, using the unweighted pair-group method with arithmetic averages (UPGMA) based on the allele frequency data, classified the accessions into three groups. The results of principal component analysis (PCA) were consistent with those of the cluster analysis. PCA showed that each of these three groups exhibited significant variation in agro-morphological traits. These findings suggest that the eight SSR and 17 ISSR primers identified could define valuable markers for genetic diversity for use by plant breeders.