Polymorphism of Microsatellite Markers in Papaya (<Emphasis Type="Italic">Carica papaya</Emphasis> L.)

A set of 81 new microsatellite markers for Carica papaya L. previously identified by data mining using freely available sequence information from Genbank were tested for polymorphism using 30 germplasm accessions from the Papaya Germplasm Bank (PGM) at Embrapa Mandioca e Fruticultura Tropical (CNPMF) and 18 landraces. The data were used to estimate pairwise genetic distances between the genotypes. A neighbor-joining based dendrogram was used to define clusters and infer possible genetic structuring of the collection. Most microsatellites were polymorphic (73%), with an observed number of alleles per locus ranging from one to eleven. The levels of observed and expected heterozygosity for 51 polymorphic loci varied from 0.00 to 0.85 and from 0.08 to 0.82, averaging 0.19 and 0.59, respectively. Forty-four percent of microsatellites showed polymorphism information content (PIC) higher than 0.50. The compound microsatellites seem to be more informative than dinucleotide and trinucleotide repeats in average alleles per locus and PIC. Among dinucleotides, AG/TC or GA/CT repeat motifs exhibited more informativeness than TA/AT, GT/CA and TG/AC repeat motifs. The neighbor-joining analysis based on shared allele distance could differentiate all the papaya accessions and landraces as well as differences in their genetic structure. This set of markers will be useful for examining parentage, inbreeding and population structure in papaya.     

Molecular characterization of the wild relatives of wheat using CAAT-box derived polymorphism

A molecular assessment of genetic diversity was performed on a set of 228 selected accessions belonging to the different Aegilops and Triticum species using CAAT-box derived polymorphism (CBDP) markers. Fifteen CBDP primers generated 141 polymorphic fragments with an average of 9.40 per primer. The average of polymorphic information content and resolving power revealed a high efficiency of CBDP markers in analyzing genetic diversity among different wheat genotypes. The diversity indexes including polymorphic loci percent, number of observed and effective alleles, Shannon’s index and gene diversity among different populations were 76.24%, 1.67, 1.49, 0.42 and 0.28, respectively. These essentially coincided with the analysis of molecular variance results, indicating that 86, 68, and 59.46% of genetic variation were found within two Aegilops and Triticum genera and their populations, respectively. Genetic relationships inferred from cluster analysis was matched with STRUCTURE analysis, disclosing the accessions were grouped based on their genomic constitution. Furthermore, these results were confirmed by principal coordinate analysis (PCoA). Taken together, our results suggest that CBDP markers will be useful for genetic diversity assessment in the domesticated and wild relatives of wheat.     

基于SSR分子标记的中国黄连木遗传多样性分析北大核心CSCD

该研究利用筛选出的7对SSR引物,对中国20个省、市、自治区的210份种质资源进行分子标记试验,分析中国黄连木种质资源遗传多样性、亲缘关系、遗传分化特点并构建DNA分子身份证,为黄连木的资源保护、种质利用提供理论依据,结果表明:(1)7对引物在210份种质中共扩增出158个等位基因位点,平均每对引物的等位基因数为22.571个。(2)基因多样性(GD)变化幅度为0.654~0.913,平均为0.804;期望杂合度(He)变化范围0.257~0.771,平均为0.532;多态信息含量(PIC)变化范围0.639~0.907,平均为0.784。(3)从不同地区黄连木群体的遗传多样性来看,观测杂合度(Ho)介于0.373~0.600之间,平均值为0.520;期望杂合度(He)介于0.632~0.811之间,平均值为0.737;从各群体间遗传分化指数(Fst)来看,黄连木各地区群体间的遗传分化值在0.015~0.099之间,各群体间的遗传分化处于中等以下水平。(4)分子方差分析(AMOVA)结果显示,黄连木的遗传分化变异以群体内为主,占总变异量的94%,群体间的变异占6%。(5)UPGMA聚类、群体遗传结构分析和PCoA分析结果相一致,全部种质被划分为两大类,西南地区群体单独为一类,其他地区单独为一类。(6)利用7对SSR引物构建了210份黄连木种质的DNA分子身份证。     

Comparative analysis of the informativeness of ISSR markers for estimating genetic diversity of horse breeds

The informativeness of six different types of ISSR markers was compared in order to evaluate genetic diversity of Mongolian, Buryat and Tuvinian horse breeds (Equus caballus). The dinucleotide-based ISSR primers ((GA)₉C, (AG)₉C, and (CA)₉G) proved to be of little use to examine genetic polymorphism among horses due to the low number of amplified and polymorphic fragments. The polymorphism information content (PIC) for the dinucleotide-based ISSR primers was 2.88 times lower than that for trinucleotide-based ISSR markers. Among the trinucleotide-based ISSR markers, CAC ISSR marker was also found to be noninformative, due to the low number of polymorphic loci identified. The highest values of the polymorphism information content (PIC) were obtained for two types of ISSR markers, based on (GAG)₆C (PIC, 3.61) and on (ACC)₆G (PIC, 2.50). Thus, the results of the present study showed that GAG and ACC ISSR markers were most informative for evaluation of genetic diversity among horses.     

Genetic diversity and structure of farm and GenBank accessions of cacao (<Emphasis Type="Italic">Theobroma cacao</Emphasis> L.) in Cameroon revealed by microsatellite markers

The genetic diversity of 400 accessions collected in cacao farms, 95 GenBank, and 31 reference accessions was analyzed using the 12 microsatellite markers. The GenBank and reference accessions were subdivided into 12 accession groups (AG) that belong to the traditional cacao genetic groups (GG) Lower Amazon Forastero (LA), Upper Amazon Forastero (UA), Trinitario, and Criollo (Cr). The 12-microsatellite loci revealed a total of 125 alleles, 113 of which were present in the farm accession group (FA). The within and between group variation for all AGs accounted respectively for 81% and 19% of the total molecular variation. The average F _is for the FA was 0.15 suggesting a moderate level of inbreeding. Significant differences for the level of gene diversity were found between the farm (0.50), GenBank (0.42 to 0.62), and reference (0.10 to 0.60) AGs. Genetic differentiation among AGs was variable with F _st values varying between 0.14 and 0.57 for the different AGs. Analysis using a Bayesian model-based method showed the existence of a high level of admixture for the farm accessions group. The LA genes were most represented in the FA (54%), followed by UA (33%) and Cr (7%). The genes of LA were also the most represented in the GenBank (48%), followed by UA (24%) and Cr (14%). Only 14% and 6% of the genes of the GenBank and farm accessions, respectively, could not be attributed to any of the reference GGs. The results suggest the predominating presence of LA genes in the Cameroon farm accessions and a high level of admixture, with apparent presence of genes of more than three GGs in most accessions. The traditional Trinitario types appear to have almost disappeared from farmers fields. The admixture must be the result of hybridization and recombination of these genes from the different GGs in seed gardens and in farmers’ fields. The use of selected farm accessions will depend on the GG that it belongs to and also on their level of heterozygosity. Further implications of the results for breeding and for introduction of new germplasm into the Cameroon GenBank are discussed.     

Comparative Analysis of Genome Diversity in Bullmastiff Dogs

Management and preservation of genomic diversity in dog breeds is a major objective for maintaining health. The present study was undertaken to characterise genomic diversity in Bullmastiff dogs using both genealogical and molecular analysis. Genealogical analysis of diversity was conducted using a database consisting of 16,378 Bullmastiff pedigrees from year 1980 to 2013. Additionally, a total of 188 Bullmastiff dogs were genotyped using the 170,000 SNP Illumina CanineHD Beadchip. Genealogical parameters revealed a mean inbreeding coefficient of 0.047; 142 total founders (f); an effective number of founders (f_e) of 79; an effective number of ancestors (f_a) of 62; and an effective population size of the reference population of 41. Genetic diversity and the degree of genome-wide homogeneity within the breed were also investigated using molecular data. Multiple-locus heterozygosity (MLH) was equal to 0.206; runs of homozygosity (ROH) as proportion of the genome, averaged 16.44%; effective population size was 29.1, with an average inbreeding coefficient of 0.035, all estimated using SNP Data. Fine-scale population structure was analysed using NETVIEW, a population analysis pipeline. Visualisation of the high definition network captured relationships among individuals within and between subpopulations. Effects of unequal founder use, and ancestral inbreeding and selection, were evident. While current levels of Bullmastiff heterozygosity, inbreeding and homozygosity are not unusual, a relatively small effective population size indicates that a breeding strategy to reduce the inbreeding rate may be beneficial.     

Analysis of Genetic Diversity in the North Eastern Himalayan Maize Landraces using Microsatellite Markers

Population DNA fingerprinting of 48 selected North Eastern Himalayan (NEH) landrace accessions was undertaken using 41 polymorphic fluorescent dye-labelled microsatellite/Simple Sequence Repeat (SSR) markers, using a DNA Sequencer. The analysis revealed a large number of SSR alleles (576), with high mean number of alleles per locus (13.8), and Polymorphism Information Content (PIC) of 0.63, reflecting the level of diversity in the NEH accessions and the informativeness of the SSR markers. The study also led to identification of 135 unique alleles, differentiating 44 out of the 48 accessions. Five highly frequent (major) SSR alleles (umc1545 _80bp, phi062 _162bp, umc1367 _159bp, umc2250 _152bp and phi112 _152bp) were detected indicating that chromosomal regions harbouring these S SR alleles might not be selectively neutral. Analysis of population genetic parameters, including Wright’s F statistics, revealed high level of genetic differentiation, very low levels of inbreeding, and restricted gene flow between the NEH landraces. AMOVA (Analysis of Molecular Variance) showed that 67 per cent of the total variation in the accessions could be attributed to within-population diversity, and the rest between the accessions. Cluster analysis of SSR data using Rogers’ genetic distance and UPGMA, showed significant genetic diversity among the landraces from Sikkim. This is the first detailed study of SSR allele frequency-based analysis of genetic diversity in the NEH maize landraces of India.     

Analysis of molecular genetic diversity and population structure in Amaranthus germplasm using SSR markers

We assessed the molecular genetic diversity and population structure of Amaranthus species accessions using 11 simple sequence repeat markers. A total of 122 alleles were detected, and the number of alleles per marker (N_A) ranged from 6 to 21 with an average of 11.1 alleles. The frequency of major alleles per locus ranged from 0.148 to 0.695, with an average value of 0.496 per marker. The overall polymorphic information content values were 0.436–0.898, with an average value of 0.657. The observed heterozygosity (H_O) and expected heterozygosity (H_E) ranged from 0.056 to 0.876 and from 0.480 to 0.907, with average values of 0.287 and 0.698, respectively. The average H_O (0.240) was lower than the H_E and gene flow (Nm), and showed substantial genetic variability among all populations of amaranth accessions. The sample groupings did not strictly follow the geographic affiliations of the accessions. A similar pattern was obtained using model-based structure analysis without grouping by species type. Knowledge of the genetic diversity and population structure of amaranth can be used to select representative genotypes and manage Amaranthus germplasm breeding programs.     

Association between host's genetic diversity and parasite burden in damselflies

Recent research indicates that low genetic variation in individuals can increase susceptibility to parasite infection, yet evidence from natural invertebrate populations remains scarce. Here, we studied the relationship between genetic heterozygosity, measured as AFLP‐based inbreeding coefficient f_AFLP, and gregarine parasite burden from eleven damselfly, Calopteryx splendens, populations. We found that in the studied populations, 5–92% of males were parasitized by endoparasitic gregarines (Apicomplexa: Actinocephalidae). Number of parasites ranged from none to 47 parasites per male, and parasites were highly aggregated in a few hosts. Mean individual f_AFLP did not differ between populations. Moreover, we found a positive association between individual's inbreeding coefficient and parasite burden. In other words, the more homozygous the individual, the more parasites it harbours. Thus, parasites are likely to pose strong selection pressure against inbreeding and homozygosity. Our results support the heterozygosity‐fitness correlation hypothesis, which suggests the importance of heterozygosity for an individual's pathogen resistance.     

云南莲瓣兰主栽品种SSR指纹图谱的构建和遗传差异分析

为了解云南莲瓣兰(Cymbidium tortisepalum)的遗传多样性,利用SSR技术对32个莲瓣兰主栽品种进行遗传变异分析,并构建莲瓣兰栽培品种的指纹图谱。结果表明,筛选出的12对多态性高、稳定性好的引物共检测到95个等位基因,每对引物检测到4~18个等位基因,有效等位基因数(N E)为61.489,平均有效等位基因数(NA)为5.124,Shannon信息指数(I)和多态性信息含量(PIC)分别为0.806~2.624和0.789~0.953。12对引物中,以引物SSR03的等位基因数、NE、观测杂合度、I和PIC最高。32个品种在12对引物上都具有不同的特异性条带,可以彼此区别。从12对引物中筛选出3对核心引物SSR02、SSR03和SSR12构建了莲瓣兰主栽品种SSR分子指纹图谱,这3对核心引物组合即可鉴定32个莲瓣兰栽培品种。这为莲瓣兰的品种鉴定、遗传多样性分析和分子育种研究提供理论基础和技术支持。     

草鱼EST-SSR标记及5个不同地域群体的遗传结构分析

以草鱼(Ctenopharyngodon idella)脑、肌肉、肝等组织构建cDNA文库,经测序获得unigenes序列45 318个,从中筛选微卫星序列共5 556个,据此设计EST-SSR引物118对,其中19对引物能够扩增出带型清晰且多态性较高的谱带。用这19个EST-SSR标记研究3个长江水系群体(石首、监利和长沙)和2个珠江水系群体(清远和肇庆)草鱼的遗传结构。结果表明,5个群体的平均多态信息含量(PIC)为0.415 4～0.460 4,显示草鱼群体的遗传多样性偏低;平均观测杂合度(Ho)为0.415 8～0.501 3,平均期望杂合度为(He)0.450 6～0.502 8,其中,长沙群体平均期望杂合度最高,为0.502 8,监利群体的平均观察杂合度和平均期望杂合度均最低,分别为0.415 8和0.450 6,即长沙群体的遗传多样性最高,监利群体的遗传多样性最低;对数据进行F-检验,结果表明,群体间的遗传分化程度低。Hardy-Weinberg平衡的卡方检验结果表明,5个群体均一定程度上偏离了平衡;聚类分析显示长沙群体、石首群体与监利群体聚成一支;肇庆群体与清远群体聚成一支,这与草鱼群体的流域分布一致。     

粗山羊草种质遗传多样性及群体结构的ISSR分析

粗山羊草分布范围广,遗传变异丰富,被认为是改良普通小麦的重要基因源。为深入了解不同来源粗山羊草种质的遗传多样性和群体结构,该研究利用ISSR分子标记对56份粗山羊草种质进行了遗传多样性和群体结构分析。结果表明:(1)16个ISSR引物共检测170条多态性位点,每个ISSR引物多态性位点为3～18条,平均为10.63条; 多态性信息(PIC)变异范围为0.17～0.85,平均为0.67。(2)粗山羊草4个群体的遗传多样性比较显示,中亚粗山羊草的群体遗传多样性水平最高(H_e=0.225 4,I=0.355 7),群体间的基因流较低(N_m=1.638 6)。(3)聚类结果在遗传相似系数约0.67处,来源于塔吉克斯坦6份和土库曼斯坦2份粗山羊草种质材料聚成一类(Group 2); 其他48份种质材料形成一大类(Group 1),其中Group 1可进一步分成3个Sub亚类,呈现出来源相同的粗山羊草种质材料倾向聚在一起。(4)群体结构分析将56份粗山羊草种质分为5个群体,其中,来源于西亚伊朗V群体种质材料遗传背景比较一致,混杂程度相对较低; 进一步分析各群体Q值,发现IV群体种质材料亲缘关系的来源相对复杂,遗传多样最为丰富。该研究结果可为粗山羊草种质亲缘关系解析、种质多样性保护提供重要参考依据,为其科学利用以及进化研究奠定基础。     

Genetic diversity of some wild almonds and related <Emphasis Type="Italic">Prunus</Emphasis> species revealed by SSR and EST-SSR molecular markers

Almond and its related wild species, which are widely distributed in Central and West Asia, have high genetic variation. This is an important source of genetic diversity for crop improvement. In this study a set of 32 SSR and 12 EST-SSR primer pairs were used to determine genetic diversity in 89 accessions of almond and other Prunus species. Most of the accessions (68) were collected from natural habitats of Iran. SSR primers amplified higher numbers of alleles than EST-SSR markers and discriminated genotypes more effectively. Results indicated high diversity among accessions. Observed heterozygosity (Ho) was 0.581. Nei’s index of diversity (He) and average number of alleles per locus (na) were 0.885 and 34, respectively. The mean value of polymorphism information content (PIC) was 0.874. The average Fst (F-statistics index) was 0.271 and the fixation index (Fis) was 0.151. Estimated variance among putative populations (AP) and individuals (AI) and within individuals (WI) were 5, 35, and 60%, respectively, which revealed that most of the variation was distributed among individuals rather than groups. Cultivated almonds were highly similar to P. fenzeliana, which is native to West Asia, supporting the importance of these regions in almond domestication. In the dendrogram of groups, minimum genetic distance was observed between Amygdalus and Orientalis groups from the Euamygdalus section. The Leptopus and Chameamygdalus sections were more distant from almonds than plums. The results also showed Dodecandra (Lycioides) series should be taxonomically classified closer to the section Euamygdalus.     

Newly developed polymorphic microsatellite markers in Job's tears (Coix lacryma‐jobi L.)

A microsatellite‐enriched library of Job's tears (Coix lacryma‐jobi L. var. Ma‐yuen Stapf) was constructed using a modified biotin–streptavidin capture method. After screening, 17 polymorphic microsatellites were used for diversity analysis among 30 Job's tears accessions. The number of alleles ranged from one to five alleles per locus with an average of 2.8 alleles. Expected heterozygosity (H_E) and polymorphism information content (PIC) ranged from 0 to 0.676 and from 0 to 0.666, respectively. The newly developed microsatellite markers are expected to be very valuable tools for evaluation of genetic diversity among large germplasm collection of Job's tears present in our Korean Gene Bank.     

A high‐quality pedigree and genetic markers both reveal inbreeding depression for quality but not survival in a cooperative mammal

Inbreeding depression, the reduced fitness of offspring of closely related parents, is commonplace in both captive and wild populations and has important consequences for conservation and mating system evolution. However, because of the difficulty of collecting pedigree and life‐history data from wild populations, relatively few studies have been able to compare inbreeding depression for traits at different points in the life cycle. Moreover, pedigrees give the expected proportion of the genome that is identical by descent (IBD_g) whereas in theory with enough molecular markers realized IBD_g can be quantified directly. We therefore investigated inbreeding depression for multiple life‐history traits in a wild population of banded mongooses using pedigree‐based inbreeding coefficients (f_ped) and standardized multilocus heterozygosity (sMLH) measured at 35–43 microsatellites. Within an information theoretic framework, we evaluated support for either f_ped or sMLH as inbreeding terms and used sequential regression to determine whether the residuals of sMLH on f_ped explain fitness variation above and beyond f_ped. We found no evidence of inbreeding depression for survival, either before or after nutritional independence. By contrast, inbreeding was negatively associated with two quality‐related traits, yearling body mass and annual male reproductive success. Yearling body mass was associated with f_ped but not sMLH, while male annual reproductive success was best explained by both f_ped and residual sMLH. Thus, our study not only uncovers variation in the extent to which different traits show inbreeding depression, but also reveals trait‐specific differences in the ability of pedigrees and molecular markers to explain fitness variation and suggests that for certain traits, genetic markers may capture variation in realized IBD_g above and beyond the pedigree expectation.     

Genetic diversity and differentiation of lotus (Nelumbo nucifera) accessions assessed by simple sequence repeats

Nelumbo nucifera (lotus) is a perennial aquatic crop of substantial economical and ecological importance. Currently, the evaluation of the genetic variation of lotus germplasm accessions using codominant simple sequence repeat (SSR) markers is significant, and it is essential for understanding the population structure of N. nucifera. Here we report the genetic diversity and differentiation of 92 N. nucifera accessions (82 cultivated varieties and 10 wild lotus) using 50 polymorphic SSR markers. A total of 195 alleles were detected, with an average of 3.9 alleles/locus. The mean polymorphic information content (PIC) and the mean expected heterozygosity were 0.43 and 0.50, respectively. The genetic relationships among accessions were estimated using an unweighted pair‐group method with arithmetic average (UPGMA) cluster and principal coordinate analysis (PCA). Both methods revealed that the lotus accessions from China and those from its adjacent Asian countries formed a single cluster, respectively. The cultivated varieties were correlated with their major characteristics in cultivation (the seed, rhizome and flower type) rather than their geographic distribution. On the basis of the Bayesian model‐based analyses, two genetically distinct groups (the seed lotus group and the rhizome lotus group) were generated, with a strong differentiation between them (F_ST = 0.57). The seed lotus group exhibited higher genetic diversity than did the rhizome lotus group. The results herein indicated that the current levels of genetic diversity and differentiation between the lotuses have been greatly influenced by artificial selection.     

Heterozygosity–fitness correlations in a wild mammal population: accounting for parental and environmental effects

HFCs (heterozygosity–fitness correlations) measure the direct relationship between an individual's genetic diversity and fitness. The effects of parental heterozygosity and the environment on HFCs are currently under‐researched. We investigated these in a high‐density U.K. population of European badgers (Meles meles), using a multimodel capture–mark–recapture framework and 35 microsatellite loci. We detected interannual variation in first‐year, but not adult, survival probability. Adult females had higher annual survival probabilities than adult males. Cubs with more heterozygous fathers had higher first‐year survival, but only in wetter summers; there was no relationship with individual or maternal heterozygosity. Moist soil conditions enhance badger food supply (earthworms), improving survival. In dryer years, higher indiscriminate mortality rates appear to mask differential heterozygosity‐related survival effects. This paternal interaction was significant in the most supported model; however, the model‐averaged estimate had a relative importance of 0.50 and overlapped zero slightly. First‐year survival probabilities were not correlated with the inbreeding coefficient (f); however, small sample sizes limited the power to detect inbreeding depression. Correlations between individual heterozygosity and inbreeding were weak, in line with published meta‐analyses showing that HFCs tend to be weak. We found support for general rather than local heterozygosity effects on first‐year survival probability, and g2 indicated that our markers had power to detect inbreeding. We emphasize the importance of assessing how environmental stressors can influence the magnitude and direction of HFCs and of considering how parental genetic diversity can affect fitness‐related traits, which could play an important role in the evolution of mate choice.     

北沙柳群体遗传多样性和遗传结构分析

以内蒙古北沙柳(Salix psammophila)国家种质资源库内9个群体(P1~P9)288个无性系为实验材料,利用TP-M13-SSR技术,选取22对具有多态性EST-SSR北沙柳引物,采用毛细管电泳对PCR产物进行检测,分析北沙柳遗传多样性、分化程度和群体遗传结构,为北沙柳种质资源库遗传管理、无性系鉴定、品种选育、遗传改良和构建指纹图谱提供理论依据。结果显示:(1)22对EST-SSR引物共检测到222个等位基因,各位点平均等位基因数(A)为10,四倍体基因型丰富度(G)和特异基因型(G1)总和分别为1 460和802个,平均特异基因型比率(P1)和种质鉴别率(P2)分别为45.86%和13.21%。(2)9个群体平均等位基因数(A)为7.475,基因型丰富度(G)为15.586,观察杂合度(Ho)和期望杂合度(He)分别为0.577和0.638。以期望杂合度He为标准,北沙柳群体遗传多样性水平最低的是P1和P9。(3)北沙柳群体遗传分化系数仅为0.02,AMOVA分子变异分析显示,北沙柳群体大部分遗传变异来自群体内(97%),群体间变异仅为3%。(4)三维主成分、聚类和Structure群体遗传结构分析显示,9个群体被划分为2个组,Mantel检验表明北沙柳遗传距离与地理距离极显著相关(r=0.684 P0.001)。研究表明,北沙柳种质资源具有丰富的遗传多样性,这是其具有耐旱、耐寒、耐高温、耐沙埋和抗风蚀等适应性较强的分子基础;北沙柳的遗传变异集中在群体内;分布区群体呈现由中心向边缘群体扩张分化的趋势。     

High efficiency and reliability of inter-simple sequence repeats (ISSR) markers for evaluation of genetic diversity in Brazilian cultivated <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. accessions

Jatropha curcas L. is found in all tropical regions and has garnered lot of attention for its potential as a source of biodiesel. As J. curcas is a plant that is still in the process of being domesticated, interest in improving its agronomic traits has increased in an attempt to select more productive varieties, aiming at sustainable utilization of this plant for biodiesel production. Therefore, the study of genetic diversity in different accessions of J. curcas in Brazil constitutes a necessary first step in genetic programs designed to improve this species. In this study we have used ISSR markers to assess the genetic variability of 332 accessions from eight states in Brazil that produce J. curcas seeds for commercialization. Seven ISSR primers amplified a total of 21,253 bands, of which 19,472 bands (91%) showed polymorphism. Among the polymorphic bands 275 rare bands were identified (present in fewer than 15% of the accessions). Polymorphic information content (PIC), marker index (MI) and resolving power (RP) averaged 0.26, 17.86 and 19.87 per primer, respectively, showing the high efficiency and reliability of the markers used. ISSR markers analyses as number of polymorphic loci, genetic diversity and accession relationships through UPGMA-phenogram and MDS showed that Brazilian accessions are closely related but have a higher level of genetic diversity than accessions from other countries, and the accessions from Natal (RN) are the most diverse, having high value as a source of genetic diversity for breeding programs of J. curcas in the world.