Genetic diversity of Stryphnodendron adstringens (Mart.) Coville determined by AFLP molecular markers

Bark extracts of Stryphnodendron adstringens (Mart) Coville a Leguminosae species, well known in Brazil as barbatimao, are popularly used as healing agent. The objective of this work was to determine the genetic diversity of S. adstringens populations and to correlate genetic distances to the production of tannins. S. adstringens accessions from populations found in Cerrado regions in the states of Goias, Minas Gerais and Sao Paulo were analyzed using the AFLP (Amplified Fragment Length Polymorphism) technique. A total of 236 polymorphic bands were scored and higher proportion of genetic diversity was found inter populations (70.9%), rather than intra populations (29.1%). F-ST value was found to be significantly greater than zero (0.2906), demonstrating the complex genetic structure of S. adstringens populations. Accessions collected in Cristalina, GO, showed higher percentage of polymorphic loci (87.3%) and the highest genetic diversity. The lowest genetic variability was detected among accessions from the population growing in Caldas Novas, GO. The genetic distance among populations was estimated using the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), which grouped populations into 3 clusters. Moreover, chemotypes with tannin concentration above 40% showed higher genetic similarity. AFLP analysis proved to be an efficient gene mapping technique to determine the genetic diversity among remaining populations of S. adstringens. Obtained results may be employed to implement further strategies for the conservation of this medicinal plant. (C) 2011 Elsevier Ltd. All rights reserved.

Genetic relatedness of Plasmodium falciparum isolates and the origin of allelic diversity at the merozoite surface protein-1 (MSP-1) locus in Brazil and Vietnam

Abstract Background Despite the extensive polymorphism at the merozoite surface protein-1 (MSP-1) locus of Plasmodium falciparum, that encodes a major repetitive malaria vaccine candidate antigen, identical and nearly identical alleles frequently occur in sympatric parasites. Here we used microsatellite haplotyping to estimate the genetic distance between isolates carrying identical and nearly identical MSP-1 alleles. Methods We analyzed 28 isolates from hypoendemic areas in north-western Brazil, collected between 1985 and 1998, and 23 isolates obtained in mesoendemic southern Vietnam in 1996. MSP-1 alleles were characterized by combining PCR typing with allele-specific primers and partial DNA sequencing. The following single-copy microsatellite markers were typed : Polyα, TA42 (only for Brazilian samples), TA81, TA1, TA87, TA109 (only for Brazilian samples), 2490, ARAII, PfG377, PfPK2, and TA60. Results The low pair-wise average genetic distance between microsatellite haplotypes of isolates sharing identical MSP-1 alleles indicates that epidemic propagation of discrete parasite clones originated most identical MSP-1 alleles in parasite populations from Brazil and Vietnam. At least one epidemic clone propagating in Brazil remained relatively unchanged over more than one decade. Moreover, we found no evidence that rearrangements of MSP-1 repeats, putatively created by mitotic recombination events, generated new alleles within clonal lineages of parasites in either country. Conclusion Identical MSP-1 alleles originated from co-ancestry in both populations, whereas nearly identical MSP-1 alleles have probably appeared independently in unrelated parasite lineages.

Are there genetic breaks between Atlantic and Pacific Yellowfin tuna (Thunnus albacares) populations? A preliminary study based on microsatellites gene variation

Yellowfin tuna (Thunnus albacares, YFT, Bonnaterre 1788) is one of the most important market tuna species in the world. The high mortality of juveniles is in part caused by their bycatch. Indeed, if unregulated, it could permanently destabilize stocks health. For this reason investigating and better knowing the stock boundaries represent a crucial concern. Aim of this thesis was to preliminary investigate the YFT population structure within and between Atlantic and Pacific Oceans through the analysis of genetic variation at eight microsatellite loci and assess the occurrence of barriers to the gene flow between Oceans. For this propouse we collected 4 geographical samples coming from Atlantic and Pacific Ocean and selected a panel of 8 microsatellites loci developped by Antoni et al., (2014). Samples 71-2-Y and 77-2-Y, came from rispectively west central pacific ocean (WCPO) and east central pacific ocean (ECPO), instead samples 41-1-Y and 34-2-Y derive from west central atlantic ocean (WCAO) and east central atlantic ocean (ECAO). Total 160 specimens were analyzed (40 per sample) and were carried out several genetic information as allele frequencies, allele number, allelic richness, HWE (using He and Ho) and pairwise Fst genetic distance. Results obtained, may support the panmictic theory of this species, only one of pairwise Fst obtained is statistically significant (Fst= 0.00927; pV= 0.00218) between 41-1-Y and 71-2-Y samples. Results suggest low genetic differentiation and consequent high level of gene flow between Atlantic and Pacific populations. Furthermore, we performed an analysis of molecular taxonomy through the use of ATCO (the flaking region between ATPse6 and cytochrome oxidase subunit III genes mt DNA, to discriminate within the gener Thunnus two of the related species (Yellofin and bigeye tuna) according with their difficult recognition at certain size (<40 cm). ATCO analysis in this thesis, has provided strong discriminate evidence between the target species proving to be one of the most reliable genetic tools capable to indagate within the genus Thunnus. Thus, our study has provided useful information for possible use of this protocol for conservation plans and management of this fish stocks.

Genetic diversity among alfalfa genotypes (Medicago sativa L.) of non-dormant cultivars using SSR markers and agronomic traits

The aim of this study was to assess genetic diversity among 40 alfalfa (Medicago sativa L.) genotypes of different non-dormant (FD=8) cultivars. Biomass yield, regrowth speed and reaction to spring black stem, lepto leaf spot, and rust were evaluated. Analyses of variances were performed using a mixed model to examine the agronomic variation among individuals. A principal component analysis on standardized agronomic data was performed. Agronomic data were also used to calculate Gower's distance and UPGMA algorithm. For the molecular analysis, six SSR markers were evaluated and 84 alleles were identified. The genetic distance was estimated using standard Nei's distance. Average standard genetic diversity was 0.843, indicating a high degree of variability among genotypes. Finally, a generalized procrustes analysis was performed to calculate the correlation between molecular and agronomic distance, indicating a 65.4% of consensus. This value is likely related to the low number of individuals included in the study, which might have underestimated the real phenotypic variability among genotypes. Despite the low number of individuals and SSR markers analyzed, this study provides a baseline for future diversity studies to identify genetically distant alfalfa individuals or cultivars.

Genetic diversity and relationships in accessions from different cultivar groups and origins in the tree tomato (Solanum betaceum Cav.)

Abstract Tree tomato (Solanum betaceum) is an Andean small tree cultivated for its juicy fruits. Little information is available on the characterization of genetic resources and breeding of this neglected crop. We have studied the molecular diversity with AFLP markers using 11 combinations of primers of a collection of 25 S. betaceum accessions belonging to four cultivar groups, most of which had been previously morphologically characterized, as well as one accession of the wild relative S. cajanumense.Atotal of 197 AFLP fragments were scored, of which 84 (43 %) were polymorphic. When excluding S. cajanumense from the analysis, the number of polymorphic AFLP fragments was 78 (40 %). Unique AFLP fingerprints were obtained for every accession, but no AFLP fragments specific and universal to any of the four cultivar groups were found. The total genetic diversity (HT) of cultivated accessions was HT = 0.2904, while for cultivar groups it ranged from HT = 0.1846 in the orange group to HT = 0.2498 in the orange pointed group. Genetic differentiation among cultivar groups (GST) was low (GST = 0.2248), which was matched by low values of genetic distance among cultivar groups. The diversity of collections from Ecuador, which we hypothesize is a center of diversity for tree tomato, was similar to that from other origins (HT = 0.2884 and HT = 0.2645, respectively). Cluster and PCoA analyses clearly separated wild S. cajanumense from the cultivated species. However, materials of different cultivar groups and origins were intermingled in both analyses. The Mantel test correlation coefficient of the matrices of morphological and AFLP distances was low (-0.024) and non-significant. Overall, the results show that a wide diversity is present in each of the cultivar groups, indicate that Ecuador may be regarded as a center of accumulation of diversity for this crop, and confirm that AFLP and morphological characterization data are complementary. The results obtained are of value for the conservation of genetic resources and breeding of tree tomato, as an assessment of the genetic diversity and relationships among differen

Microsatellite variability and genetic distances.

We analyze the within- and between-population dynamics of the distribution of the number of repeats at multiple microsatellite DNA loci subject to stepwise mutation. Analytical expressions for moments up to the fourth order within a locus and the variance of between-locus variance at mutation-drift equilibrium have been obtained. These statistics may be used to test the appropriateness of the one-step mutation model and to detect between-locus variation in the mutation rate. Published data are compatible with the one-step mutation model, although they do not reject the two-step model. Using both multinomial sampling and diffusion approximations for the analysis of the genetic distance introduced by Goldstein et al. [Goldstein, D. B., Linares, A. R., Cavalli-Sforza, L. L. & Feldman, M. W. (1995) Proc. Natl. Acad. Sci. USA 92, 6723-6727], we show that this distance follows a chi 2 distribution with degrees of freedom equal to the number of loci when there is no variation in mutation rates among the loci. In the presence of such variation, the variance of the distance is obtained. We conclude that the number of microsatellite loci required for the construction of phylogenetic trees with reliable branch lengths may be several hundred. Also, mutations that change repeat scores by several units, even though extremely rare, may dramatically influence estimates of population parameters.

Genetic absolute dating based on microsatellites and the origin of modern humans.

We introduce a new genetic distance for microsatellite loci, incorporating features of the stepwise mutation model, and test its performance on microsatellite polymorphisms in humans, chimpanzees, and gorillas. We find that it performs well in determining the relations among the primates, but less well than other distance measures (not based on the stepwise mutation model) in determining the relations among closely related human populations. However, the deepest split in the human phylogeny seems to be accurately reconstructed by the new distance and separates African and non-African populations. The new distance is independent of population size and therefore allows direct estimation of divergence times if the mutation rate is known. Based on 30 microsatellite polymorphisms and a recently reported average mutation rate of 5.6 x 10(-4) at 15 dinucleotide microsatellites, we estimate that the deepest split in the human phylogeny occurred about 156,000 years ago. Unlike most previous estimates, ours requires no external calibration of the rate of molecular evolution. We can use such calibrations, however, to test our estimate.

Molecular Characterization of Sclerospora graminicola, the Incitant of Pearl Millet Downy Mildew Using ISSR Markers

The DNA polymorphism among 22 isolates of Sclerospora graminicola, the causal agent of downy mildew disease of pearl millet was assessed using 20 inter simple sequence repeats (ISSR) primers. The objective of the study was to examine the effectiveness of using ISSR markers for unravelling the extent and pattern of genetic diversity in 22 S. graminicola isolates collected from different host cultivars in different states of India. The 19 functional ISSR primers generated 410 polymorphic bands and revealed 89% polymorphism and were able to distinguish all the 22 isolates. Polymorphic bands used to construct an unweighted pair group method of averages (UPGMA) dendrogram based on Jaccard's co-efficient of similarity and principal coordinate analysis resulted in the formation of four major clusters of 22 isolates. The standardized Nei genetic distance among the 22 isolates ranged from 0.0050 to 0.0206. The UPGMA clustering using the standardized genetic distance matrix resulted in the identification of four clusters of the 22 isolates with bootstrap values ranging from 15 to 100. The 3D-scale data supported the UPGMA results, which resulted into four clusters amounting to 70% variation among each other. However, comparing the two methods show that sub clustering by dendrogram and multi dimensional scaling plot is slightly different. All the S. graminicola isolates had distinct ISSR genotypes and cluster analysis origin. The results of ISSR fingerprints revealed significant level of genetic diversity among the isolates and that ISSR markers could be a powerful tool for fingerprinting and diversity analysis in fungal pathogens.

Lineage delimitation and description of nine new species of bush frogs (Anura: Raorchestes, Rhacophoridae) from the Western Ghats Escarpment

Bush frogs of the genus Raorchestes are distributed mainly in the Western Ghats Escarpment of Peninsular India. The inventory of species in this genus is incomplete and there is ambiguity in the systematic status of species recognized by morphological criteria. To address the dual problem of taxon sampling and systematic uncertainty in bush frogs, we used a large-scale spatial sampling design, explicitly incorporating the geographic and ecological heterogeneity of the Western Ghats. We then used a hierarchical multi-criteria approach by combining mitochondrial phylogeny, genetic distance, geographic range, morphology and advertisement call to delimit bush frog lineages. Our analyses revealed the existence of a large number of new lineages with varying levels of genetic divergence. Here, we provide diagnoses and descriptions for nine lineages that exhibit divergence across multiple axes. The discovery of new lineages that exhibit high divergence across wide ranges of elevation and across the major massifs highlights the large gaps in historical sampling. These discoveries underscore the significance of addressing inadequate knowledge of species distribution, namely the ``Wallacean shortfall'', in addressing the problem of taxon sampling and unknown diversity in tropical hotspots. A biogeographically informed sampling and analytical approach was critical in detecting and delineating lineages in a consistent manner across the genus. Through increased taxon sampling, we were also able to discern a number of well-supported sub-clades that were either unresolved or absent in earlier phylogenetic reconstructions and identify a number of shallow divergent lineages which require further examination for assessment of their taxonomic status.

Estudo de ancestralidade através de marcadores genéticos uniparentais

A chegada dos primeiros habitantes há cerca de 15.000 anos e de colonos portugueses e escravos africanos, desde o século 15, em sucessivas migrações na América do Sul, levaram à formação de populações miscigenadas com raízes consideravelmente diversificadas. É notável a heterogeneidade populacional decorrente dessas migrações e do processo de amalgamento de indígenas a partir dos contatos entre os diferentes grupos étnicos, iniciados com a colonização da América pelos europeus. A despeito da elevada miscigenação, ainda se pode encontrar no Brasil populações que, majoritariamente, mantém a identidade genética dos seus ancestrais mais remotos. O objetivo desse estudo foi caracterizar a ancestralidade da população de Santa Isabel do Rio Negro, Amazonas, com fortes traços fenotípicos ameríndios, e da tribo indígena Terena de Mato Grosso do Sul. Para isto, foram estudados marcadores uniparentais paternos ligados à região não recombinante do cromossomo Y e maternos presentes na região controle do DNA mitocondrial (mtDNA). Em relação à herança paterna, foram genotipados 31 indivíduos de Santa Isabel do Rio Negro, sendo que os Terena já haviam sido estudados sob este aspecto. Quanto ao mtDNA, foram estudados 76 indivíduos de ambos os sexos e 51 Indivíduos do sexo masculino de Santa Isabel do Rio Negro e dos Terena, respectivamente. A análise de marcadores Y-SNPs possibilitou a caracterização de 55% dos cromossomos Y dos indivíduos de Santa Isabel do Rio Negro como pertencentes ao haplogrupo Q1a3a*, característico de ameríndio. Através do mtDNA, foi verificado que o haplogrupo A é o mais frequente nas duas populações, com percentuais de 34% e 42% em Santa Isabel do Rio Negro e na tribo Terena, respectivamente, observando-se no tocante à ancestralidade materna a não ocorrência de diferenciação genética significativa entre as duas populações. Por outro lado, a análise do cromossomo Y revelou a ocorrência de distância genética significativa entre elas, o que pode ser resultante da diferença entre os tamanhos das amostras populacionais ou refletir diferenças entre rotas migratórias dos ameríndios anteriormente à colonização. Os resultados mostram ainda que os genomas mitocondriais autóctones foram melhor preservados, e que novos haplogrupos do cromossomo Y foram introduzidos recentemente na população ameríndia. É, portanto, possível concluir que a população de Santa Isabel do Rio Negro e a tribo indígena Terena apresentam um significativo grau de conservação da ancestralidade ameríndia, apesar do longo histórico de contato com europeus e africanos, os outros povos formadores da população brasileira.

Estudo do polimorfismo Ser49Gly do gene do receptor beta adrenérgico 1 (β-adr 1) na população do estado do Rio de Janeiro, Brasil estratificada por cor da pele e ancestralidade genômica

As doenças cardiovasculares possuem a maior taxa de óbitos no mundo, e notavelmente nos últimos anos as pesquisas genéticas sobre as mesmas estão baseadas em estudos de associação, no qual o gene suspeito que esteja em maior frequência entre os pacientes passa a ser considerado um possível fator causal. Os polimorfismos genéticos que ocorrem no receptor beta-adrenérgico podem resultar em mudanças significativas na função do receptor, podendo acarretar fisiopatologias. Neste trabalho, o objetivo foi estimar a diversidade e a frequência do polimorfismo Ser49Gly do gene do receptor beta-adrenérgico 1 a partir de uma amostra de 188 indivíduos da população do Estado do Rio de Janeiro. As frequências também foram analisadas a partir da estratificação da amostra por critério fenotípico em função do padrão de cor da pele em (negros e não negros) ou ancestralidade genética em (afrodescendente e não afrodescendente), definida através da informação dos marcadores de ancestralidade Indels e SNP de cromossomo Y, para avaliar se os padrões de ancestralidade ou cor da pele são fundamentais para a diferenciação e distanciamento genético. Fragmentos de interesse foram amplificados por PCR (reação de cadeia de polimerase) com primers específicos para o marcador Ser49Gly e as reações de genotipagem foram realizadas com enzimas de restrição Eco0109I. Os valores da heterozigosidade variaram entre 0,25-0,50 e 0,20-0,41 nos grupos estratificados por ancestralidade e cor da pele, respectivamente. No que diz respeito à análise do equilíbrio de Hardy-Weinberg, não houve um desvio significativo na distribuição do marcador nas amostras gerais do Estado do Rio de Janeiro, ou mesmo nas amostras estratificadas. A distribuição dos alelos na amostra dos 188 indivíduos da população geral do Rio de Janeiro (AC_RJ) mostrou uma frequência de 80,30% e 19,70% para o alelo selvagem e mutado Ser49Gly, respectivamente. A comparação das análises sobre a distribuição das frequências alélicas para este marcador mostrou a ocorrência de diferenças significativas na distribuição das frequências alélicas entre negros e não negros e afrodescendentes e não afrodescendentes. A diferença significativa observada entre os negros e afrodescendentes, foi em menor grau de distanciamento. A informação obtida em relação à ancestralidade foi crucial para a obtenção dos dados sobre o aumento da variável mutada do polimorfismo Ser49Gly nas populações negras e afrodescendentes do Estado Rio de Janeiro. Tal evidência, em combinação com estudos clínicos podem contribuir para uma análise pormenorizada do padrão de susceptibilidade à doença em questão, em falhas do mecanismo deste receptor.

大白花杜鹃菌根真菌多样性的研究

杜鹃花属(Rhododendron L.)植物分布广泛，研究发现所有的杜鹃花科植物都能形成一种特殊的菌根——杜鹃花类菌根(Ericoid Mycorrhiza)。杜鹃花类菌根对杜鹃花科植物在营养胁迫的环境下生长起到重要的作用。近几年，对杜鹃花类菌根的生物学和生态功能的研究越来越重视。我国是杜鹃花属植物资源最为丰富的国家，因此研究杜鹃花属植物菌根真菌多样性，充分利用杜鹃花特有的菌根资源，促进杜鹃花迁地保护成功具有重大的意义。 本研究以分布较广并且是中国特有的杜鹃花属植物——大白花杜鹃(Rhododendron decorum Franch.)的野生植株为研究对象，应用直接扩增根中真菌ITS区的分子鉴定方法和T-RFLP(末端限制性片段长度多态性)的分析方法，来研究其菌根真菌的多样性；并结合生态化学计量学特征分析、宿主遗传相似性及其群落组成分析等内容，探讨大白花杜鹃的菌根真菌－宿主植物－根际土壤三者之间的关系。主要结果如下： (1)通过用直接扩增真菌ITS区序列，揭示了大白花杜鹃根部真菌的多样性，本研究发现，野生大白杜鹃根部的真菌种类比较丰富，至少有26个ITS-taxa，包括子囊菌和担子菌共5个真菌目：Helotiales、Lecanorales(≡Agyriales)、Onygenales、Sebacinales和Thelephorales，其中包括典型的ERM真菌——树粉孢属Oidiodendron sp.(Myxotrichaceae)真菌。另外还发现了黑色有隔内生菌(Dark septate endophyte，DSE)以及一些未命名的子囊菌。担子菌在本研究中占有较大比例，尤其是蜡壳耳菌目真菌；此外还有较典型的外生菌根真菌——革菌目真菌。 (2)大白花杜鹃野生植株与栽培植株在菌根真菌种类组成上，有一定的相似性；在忽略种源差异等条件下相较而言，前者的物种丰富度远高于后者。 (3)大白花杜鹃菌根真菌多样性和丰富度同它的根际土壤与叶片的C、N、P含量以及C/N、N/P、土壤pH值、宿主的海拔高度等都没有显著的相关关系。 (4)在大白花杜鹃的菌根真菌群落组成方面，整体上保持了相当程度的相似性，同时还保持了一定水平的差异；大白杜鹃菌根真菌的种类是丰富的，优势度指数表明其多样性水平很高。 (5)大白花杜鹃的遗传距离与其菌根真菌群落组成结构有极显著的相关关系，宿主的种内遗传差异可能对菌根真菌群落物种组成产生选择偏好。 (6)大白花杜鹃的群落组成与其菌根真菌群落组成有极为显著的关联性，伴生种的菌根类型可能会影响宿主植物菌根真菌的物种组成结构。

Allozyme variation in four hatchery populations of Thai pangas, Pangasius hypophthalmus in Bogra, Bangladesh

Genetic variation of four hatchery stocks of Thai pangas, Pangasius hypophthalmu [sic] of Bogra region, Bangladesh was studied from 1 January 2002 to 31 December 2003. Muscle samples were collected for allozyme analysis from four (Bhai-Bhai, Jahangir, Belal and Bhai-Bon) different hatchery populations. For allozyme electrophoresis, eight enzymes were used and 11 loci viz. Adh-1*, Est-1*, GJpdh-1*, Gpi-1*, Gpi-2*, Jdhp-1*, Ldh-1*, Ldh-2*, Mdh-1*, Mdh-2*and Pgm* were identified, of which three loci (Est-1*, Gpi-2*, G3pdh-1 and Pgm*) were polymorphic in all the four populations. The mean proportion of polymorphic loci per population and the mean proportion of heterozygous loci per individual was 36.36% and 13.33, respectively for all the population studied. The highest variability measured by the mean number of alleles per locus was 1.545 in Bhai-Bon hatchery population. Based on Nei's (1972) genetic distance, the dendrogram (UPGMA) shows that four populations have made two clusters by D-value (D=0.043). Bhai-Bhai and Jahangir hatchery populations have made cluster-I, and Belal Uddin and Bhai-Bon hatchery populations formed cluster-II. Among the four populations, BhaiBhai and Jahangir hatchery populations were differentiated from each other by the D-value of 0.013, and Belal Uddin and Bhai-Bon populations were differentiated from each other by the D-value of 0.002, which suggests that the four populations may be fallen into the local population or race.

PHYLOGENY OF RHESUS-MONKEYS (MACACA-MULATTA) AS REVEALED BY MITOCHONDRIAL-DNA RESTRICTION ENZYME ANALYSIS

Mitochondrial DNA, purified from 36 samples of 23 local populations which are widely distributed in Vietnam, Burma, and 10 provinces of China, has been analyzed to model the phylogeny of rhesus monkeys. The 20 local populations of China may represent nearly all major populations in China. Using 20 restriction endonucleases of 6-bp recognition, we observed a total of 50-61 sites in the various samples. By combining the cleavage patterns for each enzyme, the 36 samples were classified into 23 restriction types, each of which was found exclusively in the respective population from which samples were obtained By combining the earlier study of Indian rhesus monkeys, phylogenetic trees, which have been constructed on the basis of genetic distance, indicate that rhesus monkeys in China, Vietnam, India, and Burma can be divided into seven groups. Integrating morphological and geographical data, we suggest that rhesus monkeys in China, Vietnam, and Burma may be classified into six subspecies-M. m. mulatta, M. m. brevicaudus, M. m. lasiotis, M. m. littoralis, M. m. vestita, and M. m. tcheliensis-and rhesus monkeys in India may be another valid subspecies. M. m. tcheliensis is the most endangered subspecies in China. Divergence among subspecies may have begun 0.9-1.6 Ma. The radiation of rhesus monkeys in China may have spread from the southwest toward the east. The taxonomic status of the Hainan monkey and the Taiwan monkey require further investigation.

Taxonomic status of the white-head langur (Trachypithecus francoisi leucoscephalus) inferred from allozyme electrophoresis and random amplified polymorphism DNA (RAPD)

Six sample specimens of Trachypithecus francoisi and 3 of T. leucocephalus were analyzed by use of allozyme electrophoresis and random amplified polymorphism DNA (RAPD) in order to clarify the challenged taxonomic status of the white-head langur. Among the 44 loci surveyed, only 1 locus (PGM-2) was found to be polymorphic. Nei's genetic distance was 0.0025. In total, thirty 10-mer arbitrary primers were used for RAPD analysis, of which 22 generated clear bands. Phylogenetic trees were constructed based on genetic distances using neighbor-joining and UPGMA methods. The results show that T. francoisi and T: leucocephalus are not monophyletic. T. francoisi from Guangxi, China and Vietnam could not be clearly distinguished, and they are not divided into 2 clusters. A t-test was performed to evaluate between genetic distances within and between T. leucocephalus and T. francoisi taxa groups. The statistical test shows that the taxa group within T: leucocephalus and T: francoisi does not significantly differ from that between T: leucocephalus and T: francoisi at the 5% level. Our results suggest that the level of genetic differentiation between T, leucocephalus and T. francoisi is relatively low. Recent gene flow might exist between T. francoisi and T. leucocephalus. Combining morphological features, geographical distribution, allozyme data, RAPD data, and mtDNA sequences, we suggest that the white-head langur might be a subspecies of T. francoisi.