Phenetic Tree Research Articles

Genetic diversity in Bambara groundnut (Vigna subterranea (L.) Verdc.) as revealed by phenotypic descriptors and DArT marker analysis

Genetic diversity of a Bambara groundnut germplasm representing accessions from 25 African countries, maintained at the International Institute of Tropical Agriculture (IITA; Nigeria) was evaluated based on seed patterns, qualitative characters, quantitative traits and Diversity Arrays Technique (DArT) markers. The study aimed at identifying important descriptors for germplasm conservation, validating the crop’s geographical centre of origin and facilitating the utilization of existing genetic resources. Frequencies and diversity indices of seven types of seed patterns, 12 qualitative and 28 quantitative traits were evaluated for 124 representative accessions and were analyzed by region to elucidate the geographic distribution of descriptor states. In addition, individual plant samples from a subset of 40 landrace accessions were analyzed by assessing 554 DArT markers. Both the phenetic tree constructed from the qualitative and quantitative descriptors and the population structure derived from DArT marker analysis suggested a relatively high genetic diversity among accessions. Higher genetic diversity was observed for the Cameroon/Nigeria region relative to other regions, in agreement with the hypothesis that this region is the centre of origin for Bambara groundnut. Use of an extensive and diverse range of germplasm and an approach that integrated morphological and quantitative descriptors with DNA markers that represent wide genomic coverage offered a powerful way to make inferences about crop germplasm, in support of crop-improvement programs.

Specific identification of some female Empoascini (Hemiptera: Cicadellidae), using morphological characters of the ovipositor and isozyme and mtCOI sequence analyses

AbstractWe identified females of six species of leafhoppers (tribe Empoascini),Asymmetrasca decedens(Paoli),Empoasca affinisNast,E. decipiensPaoli,E. pteridis(Dahlbom),E. vitisGöthe, andJacobiasca lybica(Bergevin and Zanon), using morphological characters of the ovipositor and isozyme and mitochondrial COI sequence analyses. Useful traits of the ovipositor are tooth morphology, length of the toothed area, form of sculpturing, and number and position of sensilla on the first and second pair of valves. Among the set of enzyme systems assayed, four putative loci,sod, hk-2, est-3,andest-2,together provided reliable diagnostic characters for single species, pairs of species, and groups of species. Analysis of mtCOI sequences revealed differences between the six species of Empoascini, and the neighbour-joining tree separated them into three distinct groups. Phenetic trees elaborated using Nei’s index and the Kimura two-parameter model clustered the six Empoascini species in similar groups.

Simultaneous infection of human host with genetically distinct isolates of Paracoccidioides brasiliensis

This study is the first report on genetic differences between isolates of Paracoccidioides brasiliensis from a single patient. We describe a simultaneous infection with genetically distinct isolates of P. brasiliensis in a patient with chronic paracoccidioidomycosis. The clinical isolates were obtained from lesions in different anatomical sites and were characterised by random amplified polymorphic DNA (RAPD) analysis. The RAPD technique can be helpful for distinguishing between clinical isolates. Different random primers were used to characterise these clinical isolates. The RAPD patterns allowed for differentiation between isolates and the construction of a phenetic tree, which showed more than 28% genetic variability in this fungal species, opening new possibilities for clinical studies of P. brasiliensis. Based on these results and preliminary clinical findings, we suggest that different genotypes of P. brasiliensis might infect the same patient, inducing the active form of the disease.

Analysis of phylogenetic relationships in some species of the genus Lens using ITS sequences

SummaryWe compared sequence variations in the internal transcribed spacer (ITS) region of five Lens species, including cultivated lentil (Lens culinaris subsp. culinaris) and its four wild relatives distributed in Iran and Turkey, in order to clarify their genetic relationships. Cluster analysis based on the neighbour-joining algorithm and Jukes-Cantor distances revealed a phenetic tree with a topology congruent with patterns derived by previous studies using ITS sequence analysis. Phylogenetic analysis confirmed the divergence of L. nigricans from all other species. In this study, we found that some accessions of L. culinaris subsp. orientalis were very similar to L. culinaris subsp. culinaris, the cultivated lentil, but several others were not.

Enzyme electrophoretic studies as a contribution to the systematics of the taxon Tisbe (Copepoda, Harpacticoida)1

Eight taxa of the genus Tisbe, with up to 28 laboratory populations, were analysed at four polymorphic loci (phosphoglucose isomerase, phosphoglucomutase-1, arginine phosphokinase-1 and -2), by means of vertical polyacrylamide eel electrophoresis. - Despite high intraspecific variability, and partly interspecific identity of alleles (electromorphs), the majority of the studied taxa could clearly be discriminated by at least one diagnostic locus (Nei'S genetic identity I=0) in paired comparisons. Relatively greatest discriminative power was demonstrated in arginine phosphokinase (APK-1), with 19 species pairs being differentiated, accepting probability ≥ 99 % correct diagnosis. Nevertheless, in the highly variable phosphoglucomutase (PGM-1) 14 pairs proved to be distinguishable. Including level of probability ≥99%, only one species pair (T. holothuriae Venice - T. battagliai) could not be differentiated by any of the loci examined; hence, they must be considered as the most allied of all taxa studied. - Means of genetic distance indicated different levels of divergence in the taxa, and might reflect stages in speciation process. Compared to means of genetic identity within local populations (I=0.86-1.00), the similarity between T holothuriae Venice and T. battagliai (I = 0.78) was found to be characteristic rather of the sub- or semispecies level according to AYALA (1975). Genetic affinities within three pairs T. holothuriae Venice - T. holothuriae Helgoland (I = 0.53), T. cucumariae - T. gracilis (I = 0.56), and T. bulbisetosa - T. furcata (I = 0.56), fell into the range generally covered by sibling species. The majority of the remaining taxa was well separated at the (non-sibling) species level indicated by genetic identities I ≤ 0.34. - According to the phenetic tree based on identity coefficients (UPGMA), three sets of taxa could be differentiated with their respective members probably exhibiting closer genetic interrelations: (a) T. holothuriae (Helgoland) - T. holothuriae (Venice) -T. battagliai, (b) T. bulbisetosa - T. furcata - T. clodiensis, (c) T. gracilis - T. cucumariae.

Geographic morphological variation in parapatric Western Palearctic tree frogs, Hyla arborea and Hyla savignyi: are related species similarly affected by climatic conditions?

Tree frogs Hyla arborea and Hyla savignyi are similar, closely-related species distributed in Europe and the Middle East. We investigated geographic variation in body shape within and between these species, and tested its relationships to macroclimatic conditions. We used morphometric distances (based on size corrected external measurements) to construct phenetic trees (unweighted pair-group method of arithmetical averages, Neighbour-joining), and to test correlations between morphology, geography, and climate by the partial Mantel test. Regardless of their specific affiliation, the parapatric populations of both species from the eastern Mediterranean, where they occupy comparable habitats, are closer to each other in morphospace than to conspecific populations from distal regions. This local interspecific similarity is probably driven by the common response to environment, expressed here as macroclimatic conditions. In support, the geographically close but ecologically vicariant populations of both species from the Caucasus region differ quite substantially in body shape. We suggest that climate-provoked phenotypic variation in closely-related parapatric species should be taken into account as a potential complication to character displacement in morphology. Contrariwise, morphological diversification between related species or their populations could be enhanced by habitat shifts resulting in occupation of different environmental space. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95, 539–556.

Analysis of genetic diversity in Portuguese Ceratonia siliqua L. cultivars using RAPD and AFLP markers

Although carob ( Ceratonia siliqua L.) is of great economic importance little is still known about the pattern of genetic variation within this species. Morphological characteristics based on 31 fruit and seeds of continuous characters determinant for agro-industrial uses, were compared with RAPD and AFLP markers for assessing genetic distances in 68 accessions of carob trees, from different cultivars, varieties and eco-geographic regions of Algarve. Eighteen selected RAPD primers applied to the 68 accessions produced a total of 235 fragments ranging from 200 to 2000 bp, of which 93 (40%) were polymorphic. Four AFLP selective primer combinations generated a total of 346 amplification fragments of which 110 were polymorphic. The average level of polymorphism based on four primer combinations was 31.8%. The phenetic trees based on RAPD and AFLP analyses gave high co-phenetic correlation values, and were found to be consistent in general with the analysis of morphological data, carried out on the same accessions. A number of RAPD and AFLP markers were found to be diagnostic for ‘Canela’ cultivar and 13 wild ungrafted trees.

Genetic structuring of important medicinal species of genus Warburgia as revealed by AFLP analysis

The genus Warburgia (Canellaceae) contains four tree species that are of valuable medicinal importance and are all found in Africa. Genetic diversity present in wild populations of these species is under great threat due to unsustainable harvesting for medicines and indiscrimi- nate felling for timber and agricultural expansion. There is therefore an urgent need for conservation of these species. Some authors disagree about the taxonomy of the genus and list different species as synonyms. Amplified fragment length polymorphism (AFLP) technique was used to determine the genetic relationships between three species to resolve the taxonomic confusion. The amount of genetic variation within and among populations was assessed to guide strategies for their conservation and sustainable utilization. Four AFLP primer pairs (EcoRI/MseI) generated a total of 185 amplification products. Analysis of molecular variance revealed most variation among individuals within populations (63%, P<0.0001), but variation among pop- ulations (37%, P<0.0001) was highly significant as well. Constrained analysis of principal coordinates based on the Jaccard distance confirmed the separation among popula- tions (38.2%, P<0.0001). A phenetic tree and ordination graphs showed a clear distinction of W. ugandensis from W. salutaris and W. stuhlmannii. W. ugandensis populations from Uganda and western Kenya formed a subgroup that clustered away from the rest of the W. ugandensis populations. W. salutaris and W. stuhlmannii populations showed little genetic differentiation. An implication of the data to genetic management and taxonomic clarification is discussed.

The flourishing diversity of models in theoretical morphology: from current practices to future macroevolutionary and bioenvironmental challenges

For decades, theoretical morphological studies of different groups of organisms have been successfully pursued in biological, paleontological, and computational contexts, often with distinct modeling approaches and research questions. A regular influx of new perspectives and varied expertise has contributed to the emergence of a veritable multidisciplinary outlook for theoretical morphology. The broadening of this discipline is reflected in a substantial increase in the number of models, leading to a bewildering diversity that has yet to be scrutinized. In this work, we tackle this issue in a synthetic fashion, with a quantitative meta-analysis that allows an objective comparison of theoretical morphological models treated as entities. By analogy with empirical morphospace analyses of actual organisms, we performed a multivariate ordination of a representative sample of models, producing a metaspace of models in which patterns of similarity and difference are visualized. A phenetic tree was used to characterize the relationships between models. Four major groups have been identified, and their disparity analyzed. We suggest this typology as a useful starting point to identify a core set of fundamental principles and protocols for better interpretation of the plethora of current models and for more efficient construction of models in the future. This in turn can help in diversifying the scope of macroevolutionary, developmental, and bioenvironmental questions in theoretical morphology.

AFLP assessment of genetic variability in old vs. new London plane trees (Platanus × acerfolia)

SummaryLondon plane tree (Platanus acerfolia) is a popular street tree and is a hybrid between the American sycamore and the Oriental plane tree. Using AFLP markers, genetic diversity and phenetic relationships were estimated in 38 London plane tree samples from Schenley Park, Pittsburgh, PA, USA, and from several nurseries. This investigation was intiated in order to manage, more effectively, the replanting of London plane trees in an existing (approx. 100 yearold) stand of approx. 100 trees. Four selective primer combinations generated a total of 492 amplification products, and 381 polymorphic markers were detected. Polymorphism ranged from 60 – 82%, with an average of 77%. A phenetic tree was constructed using Nei and Li’s coefficient of similarity with UPGMA. Other clustering algorithms were examined and all gave similar co-phenetic correlation values. The phenetic tree separated the nursery trees from the Schenley Park samples. Bootstrap analyses were completed, and the values gave strong support for this clade. We investigated the different propagating techniques applied between these samples. The Schenley Park plants had been grown from seed or seedlings, while the nursery plants were clonally propagated, which correlated with the observed differences in similarity coefficients. The level of genetic variability detected by AFLP analysis within these London plane tree samples suggested that this is a reliable, efficient, and effective marker system that can be used for better management of rural tree plantings.

Isolation of nucleotide binding site‐leucine rich repeat and kinase resistance gene analogues from sugarcane (Saccharum spp.)

Resistance gene analogues (RGAs) have been isolated from many crops and offer potential in breeding for disease resistance through marker-assisted selection, either as closely linked or as perfect markers. Many R-gene sequences contain kinase domains, and indeed kinase genes have been reported as being proximal to R-genes, making kinase analogues an additionally promising target. The first step towards utilizing RGAs as markers for disease resistance is isolation and characterization of the sequences. Sugarcane clone US01-1158 was identified as resistant to yellow leaf caused by the sugarcane yellow leaf virus (SCYLV) and moderately resistant to rust caused by Puccinia melanocephala Sydow & Sydow. Degenerate primers that had previously proved useful for isolating RGAs and kinase analogues in wheat and soybean were used to amplify DNA from sugarcane (Saccharum spp.) clone US-01-1158. Sequences generated from 1512 positive clones were assembled into 134 contigs of between two and 105 sequences. Comparison of the contig consensuses with the NCBI sequence database using BLASTx showed that 20 had sequence homology to nuclear binding site and leucine rich repeat (NBS-LRR) RGAs, and eight to kinase genes. Alignment of the deduced amino acid sequences with similar sequences from the NCBI database allowed the identification of several conserved domains. The alignment and resulting phenetic tree showed that many of the sequences had greater similarity to sequences from other species than to one another. The use of degenerate primers is a useful method for isolating novel sugarcane RGA and kinase gene analogues. Further studies are needed to evaluate the role of these genes in disease resistance.

ISSR을 이용한 고추나물 집단의 유전적 다양성과 계통학적 연구

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the phylogenetic relationships of eight Hypericum erectum populations in Korea. The six primers were produced 37 reproducible ISSR bands. Analysis of ISSR from individual plants of Korean H. erectum resulted in 22 polymorphic bands with 59.5%. Across populations, the mean number of alleles per locus was 1.348 and Shannon's information index was 0.203. Population Mt. Gyeryong had the highest expected genetic diversity (0.175) among all populations. When species were grouped by eight populations, within group diversity was 0.140 (HS), while among group diversity was 0.472 (G ST ) on a per locus basis. The estimated gene flow (Nm) for H. erectum was very low (0.561). It is suggested that reproductive isolation by the isolation of geographical distance among H. erectum populations and genetic drift may have played roles in shaping the population structure of this species. In phenetic tree, all populations were well separated from each other. Thus, ISSR markers are very effective in classifying natural population levels of genus Hypericum in Korea.

Genetic diversity of Rhynchosporium secalis in Tunisia as revealed by pathotype, AFLP, and microsatellite analyses

Genetic variability among 122 Rhynchosporium secalis isolates collected from barley in three regions of Tunisia was investigated using host differentials, amplified fragment length polymorphism (AFLP), and microsatellite markers. The isolates were collected from a widely grown scald-susceptible barley cultivar Rihane and a range of local landrace cultivars in geographically distinct regions with different agroclimatic conditions. Pathotypic diversity (the proportion of unique pathotypes) was high in R. secalis populations from the high (100% diversity), moderate (95%), and low (100%) rainfall areas of Tunisia, and from both Rihane (which is the sole variety grown in the high rainfall region) and local landraces (which predominate in the low rainfall area). This may reflect a general adaptability for aggressiveness and suggests that the widely grown cultivar Rihane has exerted little or no selection pressure on the pathogen population since its release in 1983. Genotypic diversity (GD), defined as the probability that two individuals taken at random had different genotypes, was high for populations from Rihane, local landraces, and different agro-ecological zones (GD = 0.96-0.99). There was low genetic differentiation among pathogen populations from different host populations (G(ST) < or = 0.08, theta < or = 0.12) and agro-ecological zones (G(ST) < or = 0.05, theta < or = 0.04), which may be partly explained by gene flow due to the movement of infected stubble around the country. There was no correlation (r = 0.06, P = 0.39) between virulence phenotype and AFLP haplotype. A phenetic tree revealed groups with low bootstrap values that did not reflect the grouping of isolates based on host, pathotype, or agro-ecological region. The implications of these findings for R. secalis evolutionary potential and scald-resistance breeding in Tunisia are discussed.

The phylogeny of polar fishes and the structure, function and molecular evolution of hemoglobin

Fishes thriving in polar habitats offer many opportunities for comparative approaches to understanding protein thermal adaptations. Investigations on the remarkable evolutionary adaptations to these environments of basic proteins such as hemoglobin, the oxygen carrier, can provide new insights into the mechanisms studied in temperate organisms and can shed light on convergent processes evolved in response to thermal adaptations. At the molecular level, hemoglobins are one of the most intriguing systems for studying the relationships between environmental conditions and adaptations. This review summarizes the current knowledge on molecular structure, biological function and phylogeny of hemoglobins of fish species living in both polar habitats but having different evolutionary histories. In benthic, non-migratory, cold-adapted fishes, the stability of thermal conditions may have generated no or few variations in selective pressures on globin sequences through evolutionary time, so that sequences retain the species phylogenetic “signal”. In pelagic, migratory, cold-adapted or temperate fishes, variations in selective pressures on globin sequences caused by variations in temperature accompanying the dynamic life style may have disrupted the phylogenetic “signal” in phenetic trees.

ISSR을 이용한 음나무속 분류군의 유전적 다양성과 관련성 비교

Inter simple sequence repeat (ISSR) markers were performed in order to analyse the phylogenetic relationships of four taxa of Castor-aralia (Kalopanax pictus): K. pictus, K. pictus var. magnificus, K. pictus var. maximowiczii, and thornless K. pictus. The 11 primers were produced 64 reproducible ISSR bands. Analysis of ISSR from individual plants of Korean K. pictus resulted in 41 polymorphic bands with 64.1%. When species were grouped by four taxa, within group diversity was 0.115 (H S ), while among group diversity was 0.467 (G ST ) on a per locus basis. The estimated gene flow (Nm) for K. pictus var. maximowiczii and K. pictus var. magnificus were very higher than K. pictus. It is suggested that the isolation of geographical distance and reproductive isolation among K. pictus populations may have played roles in shaping the population structure of this species. In phenetic tree, ISSR markers are very effective in classifying natural populations as well as taxon levels of genus Kalopanax in Korea.

Identifying the genome of wood barley Hordelymus europaeus (Poaceae: Triticeae)

Wood barley, Hordelymus europaeus, was compared with other Triticeae species by Southern and fluorescence in situ hybridisation using total genomic DNA and repetitive sequences as probes. On Southern blots, the total genomic probe from H. europaeus hybridised strongly to DNA of its own species and to Leymus and Psathyrostachys, indicating the presence of Ns genome in H. europaeus. Furthermore, the total genomic probe from P. fragilis hybridised to DNA of H. europaeus as much as to all of the Psathyrostachys and Leymus species examined. Ns genome-specific DNA sequences isolated from L. mollis (pLmIs1, pLmIs44 and pLmIs53) hybridised essentially to H. europaeus and all of the species of Leymus and Psathyrostachys. Chromosomal localization of these clones on H. europaeus confirmed the presence of Ns genome-specific DNA on all chromosomes, indiscriminately. Under moderate hybridisation stringency the Ns genome-specific probes, together with repetitive sequences pTa71 and pAesKB7, produced species-specific RFLP banding profiles on Southern blots. A phenetic tree based on these profiles revealed a distinct Ns species cluster within the Triticeae, represented by Leymus and Psathyrostachys species. Hordelymus europaeus belonged to this Ns cluster. Chromosomal mapping of the 18S-25S and the 5S ribosomal genes, together with the repetitive sequence pLrTaiI, corroborated that H. europaeus was most probably related to Leymus, especially the European/Eurasian members of sect. Leymus. In an attempt to identify the genome of H. europaeus, different approaches were employed; the results clearly showed that wood barley had the Ns basic genome and nothing else.

AFLP Analysis of the Phenetic Organization and Genetic Diversity in the Sugarcane Complex, Saccharum and Erianthus

Amplified fragment length polymorphism (AFLP) markers were evaluated for determining the phylogenetic relationships, and the diversity in the Saccharum complex using 30 clones belonging to S. officinarum, S. robustum, S. spontaneum, S. barberi, S. sinense and the related genus Erianthus. The phenetic tree of the species clones based on AFLP data was consistent with the known taxonomical relationships. AFLP gave higher resolution of closely related species into discrete groups than that by RAPD and RFLP markers, reported earlier. The levels of diversity within the various Saccharum species were also found to be higher than those obtained previously with the same set of clones using RAPD markers. The intraspecies similarity in S. barberi and S. sinense was much higher than interspecies similarity suggesting a clear separation of the two, which are considered ‘horticultural species’. The genetic similarity matrix derived from a single primer combination highly correlated (r = 0.980) with that obtained from all the 12 primer combination used in the study, thus highlighting the efficiency of a single primer combination in delineating species relationships. All the primer combinations could identify markers that are specific to each of the species and the genus Erianthus. Among the species, specific markers were highest in S. spontaneum followed by S. robustum, S. barberi, S. officinarum and S. sinense. Erianthus had a distinct profile with 30% of the total amplified fragments being specific to it. This offers great scope for identifying intergeneric hybrids, which has been very difficult using morphological traits and RAPD markers. High degree of correspondence between the results from the cluster analysis based on Jaccard's similarity index, Neighbour Joining tree based on Sokal and Michener distance matrix and AFTD (Analyses Factorielle on Table of Distances) analysis clearly demonstrated that AFLP markers would be an appropriate tool in providing better information about the relationships among the species, estimation of diversity, and in revealing species and genus specific markers that could be directly applied in sugarcane breeding programmes.

Genetic relationships within Brassica rapa as inferred from AFLP fingerprints

Amplified fragment length polymorphism (AFLP) markers were employed to assess the genetic diversity amongst two large collections of Brassica rapa accessions. Collection A consisted of 161 B. rapa accessions representing different morphotypes among the cultivated B. rapa, including traditional and modern cultivars and breeding materials from geographical locations from all over the world and two Brassica napus accessions. Collection B consisted of 96 accessions, representing mainly leafy vegetable types cultivated in China. On the basis of the AFLP data obtained, we constructed phenetic trees using MEGA 2.1: software. The level of polymorphism was very high, and it was evident that the amount of genetic variation present within the groups was often comparable to the variation between the different cultivar groups. Cluster analysis revealed groups, often with low bootstrap values, which coincided with cultivar groups. The most interesting information revealed by the phenetic trees was that different morphotypes are often more related to other morphotypes from the same region (East Asia vs. Europe) than to similar morphotypes from different regions, suggesting either an independent origin and or a long and separate domestication and breeding history in both regions.

Populations of a Connecticut River midge structured by geological history and downstream gene flow

Connecticut River midges in the genus Axarus are constrained to semi-isolated populations associated with submerged clay exposures, and gene flow between populations is restricted. I sampled larval midges from fifteen spatially separated sites in the Connecticut River and determined karyotypes for 3111 larvae in two closely related species. In one of these species, an undescribed species referred to as Axarus species varvestris, 5 chromosomal rearrangements were present as polymorphisms. Four of these are paracentric inversions, and the fifth is a terminal insertion or deletion. I used chromosomal rearrangement frequencies to calculate Nei's genetic distance measures for all pairwise population comparisons and I constructed a neighbor-joining phenetic tree for the populations using these distances. Genetic distance between populations of A. sp. varvestris increases with geographic separation, and tree structure indicates that restricted gene flow only occurs in a downstream direction. The effect of unidirectional (downstream) gene flow on population genetic structure in riverine midges is described here for the first time. A genetic break is apparent between populations associated with 12 000-year-old sediments originating in different ancient lakes. The geological break between lakes also coincides with a break in the species composition of the Axarus populations.

Application of Sequence-related Amplified Polymorphism Markers for Characterization of Turfgrass Species

A simple marker technique called sequence-related amplified polymorphism (SRAP) provides a useful tool for estimation of genetic diversity and phenetic relationships in natural and domesticated populations. Previous studies and our initial screen showed SRAP is highly polymorphic and more informative when compared to AFLP, RAPD and SSR markers. In this study, applicability of the SRAP markers to obtain an overview of genetic diversity and phenetic relationships present among cool-season (C3) and warm-season (C4) turfgrass species and their relationship with other Gramineae species were tested. Phenetic trees based on genetic similarities (UPGMA, N-J) were consistent with known taxonomic relationships. In some cases, well-supported relationships as well as evidence by genetic reticulation could be inferred. There was widespread genetic variation among C3 and C4 turfgrass species. In Dice based cophenetic matrix, genetic similarities among all species studied ranged from 0.08 to 0.94, whereas in Jaccard based cophenetic matrix, genetic similarities ranged from 0.05 to 0.85. C3 and C4 species were clearly distinguishable and a close relationship between italian ryegrass and tall fescue were obtained based on SRAP. Genome structures of turfgrasses are comparable to other Gramineae species. This research indicates that the SRAP markers are useful for estimating genetic relationships in a wide range of turfgrass species. The SRAP markers identified in this study can provide a useful reference for future turfgrass breeding efforts.