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1.
应用23个形态学特征,19个扩增片段长度多态性(AFLP)引物组合,80个随机扩增多态DNA(RAPD)引物和32个简单序列重复(SSR)引物对,比较三种分子标记法在29个杏仁栽培种和3个野生种遗传关系构建中的信息景和效率.根据预期杂合度的评价,与AFLPs和RAPDs相比,SSRs具有较高水平的多态性和较大的信息量.AFLPs预期朵合度值最低,但其辨别效率值最高,因为AFLPs能揭示每个反应中的大量条带,导致各种类型的多样性指数均较高.三种分子标记法对杏仁基因型的辨别效率均较高,只是SSRs无法辨别‘Monagha'和‘Sefied'杏仁基因型.三种分子标记法基因型相似性相关系数统计上显著,但SSR数据要低于RAPDs和AFLPs的值.尽管三种分子标记法树形图拓扑结构存在一些差异,但相似性水平均较高.SSRs、RAPDs和AFLPs的系统树图及其综合数据都能依据地理散布反映大多数栽培种的关系.AMOVA检测到每个地理组中栽培种和野生种的变异.辅助程序分析表明,实验所应用的标记物数量足以保证基因相似性估计的可靠性和标记法间的比较是有意义的.  相似文献   

2.
Chinese fir [Cunninghamia lanceolata(Lamb.)Hook] is a major timber tree species in China.In the present study,sequence-related amplified polymorphism(SRAP) markers were used to evaluate the polymorphisms,diversity,and relationships in a collection of Chinese fir elite genotypes(n=103) from the Lechang provenance,an endangered provenance.Thirty-five SRAP primer combinations produced 620 bands among the tested 103 Lechang provenance genotypes and 17 non-Lechang provenance genotypes;577(93.1 %) of these were polymorphic,yielding an average of 16.5 polymorphic bands per primer combination.Of the SRAP primer combinations(n=35),14 ones identified C70.0 % of the 120 genotypes.The Me12–Em19 combination had the strongest discriminatory ability with 93.3 % of the genotypes identified.An UPGMA dendrogram further showed that most of the Lechang provenance genotypes(87.4 %) grouped together(Cluster A).The Lechang genotypes had a considerable amount of genetic variation with genetic similarity from 0.40 to 0.81.The current work may facilitate the management of the endangered Lechang Chinese fir provenance.  相似文献   

3.
Information on population genetic structure and crop genetic diversity is important for genetically improving crop species and conserving threatened species. The PAL gene sequence is part of a multigene family that can be utilized to design DNA marker systems for genetic diversity and population structure investigation. In the current study, genetic diversity and population structure of 100 accessions of wild Pistacia species were investigated with 78 PAL markers. A protocol for using PAL sequences as DNA markers was developed. A total of 313 PAL loci were recognized, showing 100% polymorphism for PAL markers. The PAL markers produced relatively more observed and effective alleles in Pistacia falcata and Pistacia atlantica, with a higher Shannon’s information index and expected heterozygosity in P. atlantica, Pistacia vera and Pistacia mutica. Pairwise assessment of Nei’s genetic distance and genetic identity between populations revealed a close association between geographically isolated populations of Pistacia khinjuk and Pistacia chinensis. The accessions of wild Pistacia species had more genetic relationship among studied groups of species. Analysis of molecular variance indicated 19% among-population variation and 81% within-population variation for the PAL gene based DNA marker. Population structure analysis based on PAL revealed four groups with high genetic admixture among populations. The results establish PAL markers as a functional DNA marker system and provide important genetic information about accessions from wild populations of Pistacia species.  相似文献   

4.
油橄榄品种表型和SSR标记的多样性及聚类分析   总被引:1,自引:1,他引:0       下载免费PDF全文
[目的]利用表型性状和分子标记,对我国油橄榄品种进行鉴定和遗传多样性研究,有利于种质资源保存和利用,对了解油橄榄品种的组成结构及未来的引种和育种工作都具有重要意义。[方法]以甘肃省陇南市17个油橄榄品种为研究材料,利用表型上15个数量性状、18个质量性状和8个SSR荧光标记分别进行多样性和聚类分析。[结果]各性状在品种间存在显著差异,数量性状和质量性状的表型多样性指数分别介于1.579 2.089和0.3621.091,8个SSR位点共检测到51个等位基因变异,平均每个位点等位基因数为6.375个,利用表型性状和SSR标记可以将17个品种完全区分开。[结论]17个油橄榄品种具有较丰富的表型和遗传多样性,基于表型数量性状、质量性状和SSR标记的聚类分析结果,判别品种间遗传关系的结果有一致的,也存在一定差异。对于表型性状相似的品种,需结合SSR标记进行品种鉴定。  相似文献   

5.
The endangered Vatica mangachapoi, a long-lived, tropical tree with economic and ecological importance found in Hainan, China, was used to assess the hypothesis that historical human activities in Hainan’s tropical rain forest could have negative effects on the genetic diversity of V. mangachapoi. Three hundred and twenty individuals from 11 natural populations—which were classified into three groups according to levels of disturbance—were sampled and analyzed with ISSR markers. Although genetic diversity of V. mangachapoi is high at the species level, it is relatively low within populations. A significant genetic differentiation occurs among different disturbance levels. Significant isolation-by-distance indicated relevant historical anthropogenic changes. Our findings showed that historical human disturbances significantly increase the genetic differentiation and slightly decrease the genetic diversity of long-lived tree V. mangachapoi. Relevant targeting conservation actions were recommended.  相似文献   

6.
为探讨Genomic-SSR与EST-SSR标记在桉树种间的遗传差异,本研究利用两种不同来源的SSR标记对6种桉树进行遗传差异性分析.分析结果表明:Genomic-SSR标记在6种桉树中具有高的遗传多样性,EST-SSR标记在揭示不同基因型间遗传关系方面更具优势.对两种标记进行聚类分析发现,EST-SSR标记比Genomic-SSR标记能更准确地鉴别基因型.两种不同来源SSR标记的遗传差异性,为更有效利用SSR标记在桉树遗传多样性分析、种质鉴定等相关研究提供了理论支持.  相似文献   

7.

Key message

Tetracentron sinense Oliver, an endangered species from China, displays a low within-population genetic diversity and high genetic differentiation among populations, and the existing populations could be divided into three conservation and management units.

Context

The endangered tree Tetracentron sinense Oliver has great value; however, little is known regarding the within-population genetic diversity and differentiation among T. sinense populations.

Aims

We examined the genetic diversity and differentiation of T. sinense wild populations, and we tested the effect of small-size population on the level of genetic diversity within these populations.

Methods

Using inter-simple sequence repeat (ISSR), we assessed the genetic variation and structure among 174 individuals from 26 natural populations of T. sinense sampled across its distribution range in China.

Results

The ISSR primers yielded 180 amplified loci (123 were polymorphic). At the species level, the percentage of polymorphic loci (PPL), Nei’s gene diversity (H), and Shannon’s information index (I) were 68.3%, 0.196 and 0.300, respectively. The average population level PPL was 20.0%, and the Na, Ne, H, and I were 1.20, 1.13, 0.076, and 0.112, respectively. AMOVA revealed high genetic differentiation among populations (52.0% of total variance, P?=?0.001), consistent with the gene differentiation coefficient (Gst?=?0.607) and gene flow (Nm?=?0.326). The 174 individuals of the 26 T. sinense populations clustered into three groups, and T. sinense geographic and genetic distance were significantly correlated.

Conclusions

T. sinense exhibited intermediate within-species genetic diversity, indicating preserved evolutionary potential. The low within-population genetic diversity and high genetic differentiation among T. sinense populations may be one of important factors causing endangerment. Three conservation units were determined based on genetic difference and structure. Inter-population introduction of individuals within units via appropriate propagation and seedling management might be an effective strategy for increasing T. sinense within-population genetic diversity and population size.
  相似文献   

8.
Rich genetic polymorphism is important for plants to adapt to changes because it enables the plant to make anatomical, physiological and biochemical changes in response to abiotic stress. Geomorphologic characteristics, demographic interference and a cumulative decrease in freshwater influx in the Indian Sundarbans region have proved detrimental to some economically important plants. In this study, genetic polymorphism of three mangrove species, Xylocarpus granatum, Excoecaria agallocha, and Phoenix paludosa, was assessed using RAPD and ISSR molecular markers. X. granatum, already in distress in the Sundarbans, had the least genetic polymorphism, 14.56% in the RAPD analysis and 12.92% in the ISSR. Relatively higher genetic polymorphism was recorded for the profusely growing E. agallocha and P. paludosa: 24.66 and 26.4% in RAPD; 24.87 and 20.32% in ISSR analysis respectively. A UPGMA dendrogram constructed using the similarity matrix from RAPD, ISSR and combined data showed that for X. granatum, the least and highest salinity zones clustered together, whereas for E. agallocha and P. paludosa, higher and lower salinity areas clustered in different clades. Nei’s genetic diversity, calculated from RAPD and ISSR data, was also in accordance with 0.0637 and 0.0583 for X. granatum, respectively, much lower than 0.0794 and 0.0818 for E. agallocha and 0.0799 and 0.0688 for P. paludosa. This opposing degree of polymorphism might be attributed to the profusely growing E. agallocha and P. paludosa and precarious status of X. granatum throughout the Indian Sundarbans.  相似文献   

9.
【目的】开发适于黑莓Rubus spp.的EST-SSR引物,用于品种和种质的遗传多样性评价分析。【方法】基于前期获得的黑莓转录组数据,分析得到黑莓EST-SSR分子标记,筛查符合要求的SSR序列,设计合成127对较理想的EST-SSR引物进行扩增和多态性引物筛选,利用多态性好的引物用于18个引种黑莓栽培品种的遗传多样性分析。【结果】在127对引物中有125对可扩增出条带,有特异条带且大小符合预期的引物共有50对,50对引物中有45对具多态性的引物,占引物总数的36%,多数引物扩增的位点数为2~5。使用45对引物检测18个黑莓供试品种基因组DNA的多态性,共检测到191个等位基因变异,平均每个位点有4.24个等位基因,位点多态性信息含量为0.427~0.893,平均值为0.692。多态性最好的引物为Rh121,检测到8个等位基因,其次是Rh114和Rh118,均检测到7个等位基因。18份材料的遗传相似系数为0.49~0.88,表明品种间具有较丰富的遗传差异。利用UPGMA聚类,将18份种质分为3个类群,其中四倍体和多倍体黑莓品种明显归为不同类型,四倍体黑莓分为2类,相似育种产地的品种多聚在一起,推测与其品种遗传种质成分具一定相似性有关。【结论】EST-SSR标记可应用于黑莓品种种质遗传多样性分析,目前引种黑莓种质的遗传基础相对较窄。  相似文献   

10.
16个早实核桃良种遗传多样性的FISH-AFLP分析   总被引:4,自引:3,他引:1       下载免费PDF全文
采用FISH-AFLP技术,筛选9对E+3和M+3引物组合,对我国首批16个早实核桃良种进行了基因组DNA水平上的检测,结果表明:共获得1 072条可统计的条带,其中946条呈多态性,平均的多态性带百分率达88.12%;经9对引物检测的16个品种基因型各不相同,均得到数目不等的特征带,并能将16个早实核桃良种完全区分开。研究分析了早实核桃良种的遗传多样性和亲缘关系并建立了它们的指纹图谱。  相似文献   

11.
RAPD (randomly amplified polymorphic DNA) markers were employed to characterize polymorphisms among 5 provenances of Acacia leucophloea and to detect genetic relatedness of the species with 6 other acacias (A. holosericea, A. auriculiformis, A. mangium, A. dealbata, A. ferruginea, and A. nilotica) widely grown in India. Of 194 markers scored for the provenances, 29.38% exhibited polymorphism. Also, 326 markers were generated among 7 species of Acacia, accounting for 55.82% of the polymorphisms. The fifteen 10-mer primers employed were capable of producing 1–8 polymorphic bands for the provenances, and 6–17 for all seven species of Acacia. The genetic similarity coefficient based on Jaccard’s coefficient revealed that provenances Thirumangalam and Dharmapuri were closely related. The dendrogram based on a sequential agglomerative hierarchical non-overlapping (SAHN) clustering analysis grouped 4 provenances of A. leucophloea (Dharapuram, Thirumangalam, Pudukottai and Dharmapuri) into one cluster and the other provenance, Sendurai, into a separate cluster. The genetic similarity matrix for 7 Acacia species showed that A. nilotica and A. dealbata were distantly related, while A. holosericea and A. ferruginea were very closely related. Cluster analysis grouped the species of Acacias into 3 major groups of which A. dealbata alone formed a separate group. The RAPD markers generated 36 provenance-specific markers and 162 species-specific markers that could have strong applications for species identification and tree breeding programs for A. leucophloea and for other Acacia species included in this study.  相似文献   

12.
Acer mono Maxim. is one of the major components of cool temperate forests in Japan. Some of its many varieties are distributed sympatrically. Because of its great variability, the intraspecific taxonomy and nomenclature of the species are controversial. To understand the genetic relationships among these varieties and whether hybridization or introgression occurred among the sympatric varieties, we studied the genetic relationships among sympatric varieties of A. mono in the Chichibu Mountains (A. mono var. ambiguum, A. mono var. connivens, A. mono var. marmoratum) and Central Hokkaido (A. mono var. mayrii and A. mono var. glabrum) in Japan. Our results showed that varieties in Chichibu are genetically close, suggesting that hybridization or introgression might occur between these varieties, which could explain the higher genetic diversity of varieties in Chichibu than in Hokkaido. In contrast to the close relationships between the varieties in Chichibu, varieties in Hokkaido seemed relatively separated from each other; indeed, there may be reproductive isolation between the two varieties. The results provide new insight for the taxonomy of the varieties of A. mono, especially the sympatric varieties, in Japan.  相似文献   

13.
利用RAPD标记研究选自杉木第2代育种试验林、拟纳入高世代育种的182个优良基因型的遗传变异.29条随机引物扩增出311条谱带,其中多态性谱带245条(78.8%).聚类分析表明,182个优良基因型可聚为11类.AMOVA分析表明,96.8%的遗传变异存在于第2代育种试验林内,而试验林间的遗传变异虽然显著(Φst=0.032,P<0.001),但比例较低(3.2%).研究结果表明,杉木第2代育种群体存在高水平的遗传多样性,显示了进一步育种的良好潜力.  相似文献   

14.
Although European beech (Fagus sylvatica L.) is one of the most widespread and ecologically and commercially most important deciduous trees in Europe, little is known about its adaptive genetic variation. We explored single-nucleotide polymorphism (SNP) variation in candidate genes for budburst and drought resistance in beech populations sampled across most of the distribution range, represented in an international provenance trial. SNP variation was monitored for six candidate genes, in 114 individuals from 19 natural populations. Population structure was deduced from the analysis of 20 nuclear microsatellite markers. Different methods to detect imprints of natural selection were used (F ST-outlier, SNP-climate regression, association tests). The F ST-outlier approach identified the COV gene with unambiguous signal of selection, which is an orthologue of Arabidopsis gene for a membrane protein previously reported as phenology-related. Based on environmental association analysis at the population level, the dehydrin gene was found associated with drought-related climatic variables. At the individual level, dehydrin gene also showed a significant association with chlorophyll fluorescence parameters, which are considered stress markers. The importance of the knowledge of physiological variation and geographical patterns of adaptive genetic variation for guiding reproductive materials transfer under climate change is stressed.  相似文献   

15.
Yellowwood (Cladrastis kentukea) grows in small, widely scattered populations in the wild, but is also a popular ornamental tree that thrives when planted in urban areas outside its natural range. Since the small native populations of yellowwood in several states are considered at risk of extirpation, the cultivated population could serve as an ex situ repository of yellowwood genetic diversity that could be used to restore lost local populations of the species. The potential value of cultivated yellowwood for conservation depends on the genetic diversity among cultivated trees compared to natural populations. Using nuclear microsatellite markers, we genotyped 180 yellowwoods from natural populations in Indiana, Missouri, Arkansas, and Kentucky, along with 61 trees from urban parks and landscapes in Indiana, Ohio, and Missouri. We found that, even when statistics were adjusted based on population size, the urban “population” had higher genetic diversity than any of the wild populations sampled, indicating that commercially-grown yellowwood is most likely a mixture of genotypes from isolated wild populations. We observed strong genetic differentiation among wild populations, and evidence for inbreeding in at least one of the wild populations.  相似文献   

16.
引进葡萄柚品种基因资源的AFLP分析   总被引:3,自引:0,他引:3  
采用AFLP分子标记技术,对引进的9个葡萄柚品种基因资源进行分析,评价引进资源的遗传多样性,揭示遗传结构和品种间亲缘关系,为引进葡萄柚品种的进一步开发利用和遗传改良提供基础信息。结果表明,筛选出的7对引物共扩增出263条带,多态带比率为7.22%。多态性标记百分率、观测等位基因数、有效等位基因数、Nei’s基因多样性指数和Shannon信息指数在物种水平分别为7.22%、0.023 4、0.008 0、0.6592和0.258 5,而在品种水平它们分别为2.41%、1.024 1、1.013 2、0.008 0和0.012 2。基因分化系数Gst为0.659,表明葡萄柚的遗传差异主要来自于品种之间。9个品种间的遗传距离变幅在0.000 5~0.037 1之间,平均为0.025 8。基于UPGMA的聚类结果将9个品种分为2组,火焰、矮化、亨路比、哈路比、帕利斯和瑞路比聚为一组,里德马叙、里约红和星路比构成另一组。  相似文献   

17.

Key message

The genetic structure of Juniperus phoenicea in the Mediterranean Basin is inferred using amplified fragment length polymorphism markers (AFLP) markers. As other Mediterranean conifers, J. phoenicea populations show moderate levels of genetic diversity and interpopulational differentiation. The pattern of distribution of genetic diversity seems highly influenced by the climatic fluctuations which occurred in the Pleistocene.

Context

It has been stated that the genetic structure of Mediterranean conifers is mediated by the historical climatic changes and the geological rearrangements which occurred in the Mediterranean Basin. J. phoenicea provides an excellent example to test how its genetic structure is influenced by these events.

Aims

In this work, we study the amount and distribution of genetic diversity of J. phoenicea complex, in order to evaluate its taxonomic status and to reveal underlying phylogeographic patterns.

Methods

The molecular diversity was analyzed for 805 individuals from 46 populations throughout its distribution range using AFLP markers. Principal coordinate analysis, analysis of molecular variance (AMOVA), and Bayesian-based analysis were applied to examine the population structure.

Results

AFLP markers revealed moderate levels of intrapopulation genetic diversity, pairwise genetic differentiation, and a clear pattern of isolation by distance. Bayesian analysis of population structure showed five clusters related to the taxonomic status of J. phoenicea and J. turbinata, and a geographic pattern of genetic structure in J. turbinata.

Conclusion

All the analysis separate J. phoenicea from J. turbinata. For J. turbinata, up to four groups can be distinguished from a phylogeographic point of view. The genetic structure of J. turbinata seems highly influenced by climatic and geologic fluctuations occurring since the Oligocene.
  相似文献   

18.
In this study, 28,691 genome sequences and 16,566 expressed sequence tags (ESTs) of Eucalyptus were derived from the GenBank database. A total of 2292 SSR loci were sought out from 1785 effective sequences. Through analyses of SSR loci information, the SSR motif length was negatively correlated with the abundance of the SSRs. In the EST sequences of Eucalyptus, triplet repeat motifs were the most abundant, and dinucleotide repeats motifs had the highest frequencies. Subsequently, 395 pairs of primers were designed based on the SSR loci. Using optimized SSR-PCR conditions, 340 pairs of primers were successfully screened, with a success rate of 86.1%. By construction of a maximum likelihood phylogenetic tree of six eucalypt species, represented by five species of the genus Eucalyptus and one of the genus Corymbia, the genetic relationships of Eucalyptus urophylla and E. camaldulensis suggested by this tree was found to differ from that suggested by traditional morphological taxonomy. The results provide insights for evaluating genetic diversity of Eucalyptus and analysis of Eucalyptus phylogenetics using SSR markers.  相似文献   

19.
Pieris japonica is a poisonous tree species that is rarely eaten by herbivorous animals, a fact that could enable the expansion of its distribution range and influence ecosystems into which it encroaches. In a regional-scale study, 300 P. japonica trees from 13 populations were sampled at the University of Tokyo Chichibu Forest, Japan, and were analyzed using 11 microsatellite markers. Genetic differentiation among the populations was low (F ST = 0.022 and G′ ST = 0.024). A plot (30 × 30 m) was established for a fine-scale study, in which all P. japonica trees and saplings were measured and genetically analyzed using the microsatellite markers. Using this approach, we detected 84 genotypes among the 121 P. japonica trees in the plot. A few genotypes had expanded by more than 5 m, indicating that the ability to reproduce asexually could facilitate P. japonica trees to remain in a given location. Autocorrelation analysis showed that the extent of nonrandom spatial genetic structure was approximately 7.0 m, suggesting that seed dispersal was limited. KINGROUP analyses showed that 44 genotype pairs were full siblings, 23 were half-siblings, and 40 were parent-offspring. Only 32 seedlings were observed, of which 15 had reproduced asexually. The number of P. japonica trees has been increasing gradually for more than half a century in our study areas.  相似文献   

20.
Betel vine has been identified as an important cash crop in India. It is a vegetatively propagated plant and more than 100 landraces (cultivars) are cultivated in India. They are often named after the localities where they are grown. To assess the molecular genetic diversity among 10 betel vine cultivars, amplified fragment length polymorphism (AFLP) markers were used. Five AFLP primer combinations produced 323 bands of which 155 were polymorphic, leading to a 47.99% polymorphism. Average polymorphic information content (PIC) was 0.14 over all primer combinations. Genetic similarity was calculated from the Jaccard's similarity coefficient (r) value for all accessions which varied from 0.39 to 0.81, with an average of 0.60 implying a medium level of genetic variation between investigated cultivars. Cluster analysis divided the cultivars into two main clusters where M2 and M3 were closely related but F3 was separate from all others. The cluster analysis based on AFLP data indicated that cultivars were not grouped according to their geographic place of collection but rather by genetic relatedness. The principle coordinate analysis (PCA) of the markers was linked to the dendrograms generated by employing UPGMA.  相似文献   

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