Isozyme variation in species of the section Comopyrum of Aegilops

Genetic variation at 21 enzyme loci was studied in Aegilops comosa and Ae. uniaristata, the two species belonging to section Comopyrum of Aegilops. In Ae. comosa, the mean number of alleles per locus was 2.00 and the proportion of polymorphic loci was 0.667; in Ae. uniaristata they were 1.19 and 0.143, respectively. The two species were genetically distant from each other (I=0.561) supporting the previously assigned different genome symbols, M and N.     

Evidence of rapid evolution and incipient speciation in Vicia sativa species complex based on nuclear and organellar RFLPs and PCR analysis

Seventy three accessions of the sevenVicia species belonging to Sativa speciescomplex were screened for nuclear and organellar restriction fragmentlength polymorphic (RFLP), and random amplified polymorphicDNA (RAPD) markers. Total genomic DNAs of 73 accessions wasrestricted with three enzymes, and the restriction fragments werehybridized to the wheat rDNA probe pTa71 (containing 18S, 5.8Sand 25S rDNA genes, and spacers), and faba bean probes Ver6-5 (entire intergenic spacer flanked by small part of25S and 18S fragments) and Ver 18-6 (part of thecoding region of the gene and internal transcribed spacers). InXbaI digests, 16 repeat unit length classes in24 combinations were identified. Digestion withEcoRI and DraI gave2–4 and 1–3 fragments, respectively, with detectablehybridization to the probes, indicating the existence of internalXbaI sites. All the accessions produced 3.5 EcoRI fragment arising fromcoding region of the repeat unit. Four hundred and eighteen RAPDmarkers among 45 accessions were identified with 14 arbitrary10-base primers. The percentage of polymorphic bands withinspecies ranged from 20 in V.angustifolia to 98% inV. nigra. Both RFLP andRAPD markers were unable to assess the relationships betweenaccessions within species as there was often much closer resemblancesbetween certain accessions of different species rather than betweenaccessions within each taxon. This analysis supports the view basedon morphological, cytogenetical and crossability data that it is notpossible to classify Sativa species complex into a small finitenumber of taxa which are clearly circumscribed, and that the complexrepresents a unique case of rapid evolution and incipient speciation.A study of chloroplast and mitochondrial RFLPs was undertaken toanalyze phylogeny through maternal lineage. Chloroplast DNArestriction fragment patterns, using 13 restriction endonucleases,revealed 92.6 to 99% homology between the seven species.Twelve enzyme-probe combinations yielded identical fragmentpatterns for all the seven species. The molecular sizes of thechloroplast DNAs obtained were similar (121.5–123.5), indicating that they had all lost one of theinverted repeats. Total DNAs digested with three restriction enzymesand hybridized to six heterologous probes of mitochondrial originyielded monomorphic bands in five enzyme—probe combinationsacross all the 73 accessions. In other combinations as well,40–66 accessions yielded monomorphic profiles. The smallvariation in the remaining accessions was not species-specificsince the same profiles were present in more than one species. Theseresults i) strongly suggest that the seven species within thecomplex share a common ancestor, or direct lineage and, ii)indicate that these species should be relegated to a rank, perhaps ofsubspecies, within V.sativa species complex.     

Genetic diversity and intra-specific phylogeny of Triticum turgidum L. subsp. dicoccon (Schrank) Thell. revealed by RFLPs and SSRs

Today, emmer wheat, T. turgidum subsp. dicoccon, widely grown in the past is a candidate crop for sustainable agriculture in Italy. As part of a research project aimed at the enhanced use of the hulled wheat germplasm, molecular characterization was carried out to understand the genetic structure of the crop and to identify accessions of interest. A collection of 194 accessions was analyzed with 15 microsatellite loci (SSRs), while only a sample of 38 accessions was tested with 19 RFLP probes. The marker loci were selected on the basis of their independent genomic distribution. Genetic distances and allelic frequencies were calculated for each marker class. The genetic relationships were visualized with dendrograms. RFLP loci were, on average, less polymorphic than SSRs. An average Dice's genetic distance of 0.22 for RFLPs vs 0.38 for SSRs was detected, while an expected average heterozygosity per locus of 0.23 for RFLPs vs 0.26 for SSRs was also estimated. With a least number of 10 loci per marker class it was possible to identify each genotype. The most diverse accessions had different geographic origins. Germplasms from Italy and Ethiopia appear to belong to a more primitive genepool, given that a group of accessions from these countries were genetically differentiated from a Russian-Iranian group.     

RFLP analysis of mitochondrial DNA in eggplant and related Solanum species

RFLP analysis of mitochondrial DNA (mtDNA) was performed by the Southern hybridization method using total DNA extracted from eggplant, Solanum melongena L., and six related Solanum species, S. surattense Burm. (i.e. S. virginianum L.), S. torvum Swartz, S. gilo Raddi (i.e. S. aethiopicum), S. integrifolium Poir. (i.e. S. aethiopicum), S. indicum auct. non L. (i.e. S. violaceum Ort.) and S. sanitwongsei Craib. Forty-one fragments were detected by the analysis using 12 combinations of four restriction enzymes and three probes of mtDNA clones from rice. Thirty-four out of the 41 fragments were polymorphic among the species, whereas the other seven were monomorphic. This RFLP analysis of mtDNA is demonstrated to be appropriate for assessing phylogenetic relationships in eggplant and related Solanum species at the interspecific level.     

Genetic Characterization of Brazilian Annual <Emphasis Type="Italic">Arachis</Emphasis> Species from Sections <Emphasis Type="Italic">Arachis</Emphasis> and <Emphasis Type="Italic">Heteranthae</Emphasis> using RAPD Markers

The genus Arachis is divided into nine taxonomic sections. Section Arachis is composed of annual and perennial species, while section Heteranthae has only annual species. The objective of this study was to investigate the genetic relationships among 15 Brazilian annual accessions from Arachis and Heteranthae using RAPD markers. Twenty-seven primers were tested, of which nine produced unique fingerprintings for all the accessions studied. A total of 88 polymorphic fragments were scored and the number of fragments per primer varied from 6 to 17 with a mean of 9.8. Two specific markers were identified for species with 2n = 18 chromosomes. The phenogram derived from the RAPD data corroborated the morphological classification. The bootstrap analysis divided the genotypes into two significant clusters. The first cluster contained all the section Arachis species, and the accessions within it were grouped based upon the presence or absence of the ‘A’ pair and the number of chromosomes. The second cluster grouped all accessions belonging to section Heteranthae.     

Genetic relationships among Arachis hypogaea L. (AABB) and diploid Arachis species with AA and BB genomes

The cultivated peanut (Arachis hypogaea L.) is an allotetraploid, with two types of genomes, classified as AA and BB, according to cytogenetic characters. Similar genomes to those of A. hypogaea are found in the wild diploid species of section Arachis, which is one of the nine Arachis sections. The wild species have resistances to pests and diseases that affect the cultivated peanut and are a potential source of genes to increase the resistance levels in peanut. The aim of this study was to analyze the genetic variability within AA and BB genome species and to evaluate how they are related to each other and to A. hypogaea, using RAPD markers. Eighty-seven polymorphic bands amplified by ten 10-mer primers were analyzed. The species were divided into two major groups, and the AA and the BB genome species were, in general, separated from each other. The results showed that high variation is available within species that have genomes similar to the AA and the BB genomes of A. hypogaea.     

Molecular Markers for the Classification of Switchgrass (Panicum virgatum L.) Germplasm and to Assess Genetic Diversity in Three Synthetic Switchgrass Populations

Information regarding the amount of genetic diversity is necessary to enhance the effectiveness of breeding programs and germplasm conservation efforts. Genetic variation between 21 switchgrass genotypes randomly selected from two lowland (‘Alamo’ and ‘Kanlow’) and one upland (‘Summer’) synthetic cultivars were estimated using restriction fragment length polymorphism (RFLP) markers. Comparison of 85 RFLP loci revealed 92% polymorphism between at least two genotypes from the upland and lowland ecotypes. Within ecotypes, the upland genotypes showed higher polymorphism than lowland genotypes (64% vs. 56%). ‘Kanlow’ had a lower percent of polymorphic loci than ‘Alamo’ (52% vs. 60%). Jaccard distances revealed higher genetic diversity between upland and lowland ecotypes than between genotypes within each ecotype. Hierarchical cluster analysis using Ward's minimum variance grouped the genotypes into two major clusters, one representing the upland group and the other the lowland group. Phylogenetic analysis of chloroplast non-coding region trnL (UAA) intron sequences from 34 switchgrass accessions (6 upland cultivars, 2 lowland cultivars, and 26 accessions of unknown affiliation) produced a neighbor-joining dendrogram comprised of two major clusters with 99% bootstrap support. All accessions grouped in the same cluster with the lowland cultivars (‘Alamo’ and ‘Kanlow’) had a deletion of 49 nucleotides. Phenotypic identification of greenhouse-grown plants showed that all accessions with the deletion are of the lowland type. The deletion in trnL (UAA) sequences appears to be specific to lowland accessions and should be useful as a DNA marker for the classification of upland and lowland germplasm.     

Genetic Diversity within and Between Populations of Lathyrus genus (Fabaceae) Revealed by ISSR Markers

In order to evaluate the genetic diversity in Lathyrus genus, the Inter Simple Sequence Repeats method (ISSR) was exploited in five populations. These consisted of two cultivated species belonging to section Lathyrus (L. sativus L. and L. cicera L.) and a wild one belonging to the section Clymenum (L. ochrus DC.). Two 3′anchored ISSR primers and two unanchored ones, generated a total of 60 useful polymorphic DNA bands. Our data provide evidence of high molecular polymorphism at the intra- and the inter-specific levels showing that both wild and cultivated forms constitute an important pool of diversity. Moreover, among the generated DNA bands, a 500 bp band, totally absent in the banding patterns of the section Clymenum, appears to be a molecular marker of section Lathyrus. Results provided for lineage and suggest recent origin of these species that might have evolved from a common ancestor producing both L. ochrus species and the two other species L. sativus and L. cicera. These relationships support previous studies based on morphological variation and molecular analysis.     

Genetic Relationships and Variation among Biotypes of Dallisgrass (Paspalum dilatatum Poir.) and Related Species Using Random Amplified Polymorphic DNA Markers

The genus Paspalum L. consists of more than 400 species. Around twenty-five informal groups of species are recognized in Paspalum and the Dilatata group is of special interest because its members are excellent potential forage grasses. Seventy-five germplasm accessions, representing 15 taxa, were analyzed using randomly amplified polymorphic DNA (RAPD). Polymorphisms were observed with twenty-two primers in the Dilatata group and 16 of those were analyzed. Four hundred and four different RAPD fragments were generated, resulting in an average of 25.2 bands per primer. Among the 404 markers analyzed, 48 (11.88%) were exclusive for the P. dilatatum Poir. biotypes, 31 (7.67%) were exclusive to taxa belonging to other groups included in this study, 28 markers (6.93%) were diagnosed for other species of the Dilatata group and 16 (3.96%), for natural hybrids. Extensive RAPD variation was found among the species studied. Inter- and intra-taxonomic polymorphisms were detected. A dendrogram based on the RAPD data shows some clusters corresponding to the same taxa. However, the biotypes of P. dilatatum do not form a cluster. The present work confirms that the RAPD technique can be used to determine genetic relationships between the taxa belonging to the Dilatata group.     

Assessment of genetic diversity, and phylogenetic relationships based on ribosomal DNA repeat unit length variation and Internal Transcribed Spacer (ITS) sequences in chickpea (Cicer arietinum) cultivars and its wild species

Repeat unit length variation and internal transcribed spacer (ITS) sequences of nuclear ribosomal DNA were used to assess genetic diversity, and phylogenetic relationships in chickpea (C. arietinum) cultivars, and its related wild species. Total genomic DNAs of 76 accessions of 10 Cicer species, belonging to three sections of the genus, were restricted with seven enzymes and the restriction fragments were hybridized to heterologous ribosomal clones of wheat pTa71 and Vicia faba probes Ver 6-5 and Ver18-6. A single repeat unit length class of 11.4 kb or 10.5 kb was recognized across Cicer accessions with pTa71. The intraspecific variation was negligible in those species where more than one accession was studied, except the four C. judaicum accessions, which were different from the rest. EcoRI and DraI digests gave two and one-two fragments, respectively. All the accessions produced three and three-five bands with BamHI and SacI, respectively. Both the accessions of C. yamashitae differed in their rDNA repeat unit length as well as restriction site variation. Maximum likelihood tree with rDNA RFLP recognized five clades which were more or less congruent with the previous data. Length of ITS-1 region was more variable (235–239 bp) than the ITS-2 region (212–213 bp). Cladistic analysis of ITS data revealed two major clades, clade I consisting of C. arietinum, C. reticulatum and C. echinospermum, and clade II comprised of C. judaicum, C. chorassanicum, C. bijugum and C. cuneatum. C. microphyllum grouped with the above four species. C. pinnatifidum was present as a separate branch. C. yamashitae emerged as the most distinct species.     

Relationships among <Emphasis Type="Italic">Avena</Emphasis> species as revealed by consensus chloroplast simple sequence repeat (ccSSR) markers

Consensus chloroplast simple sequence repeat (ccSSR) makers were used to assess the genetic variation and genetic relationships of 80 accessions from 25 taxa of the genus Avena. Fifteen out of 16 ccSSR markers (93.75%) were polymorphic. A total of 51 alleles were detected at the 16 ccSSR loci. The number of alleles per locus ranged from 1 to 6, with an average of 3.2 alleles. Among these ccSSR loci, the highest polymorphism information content (PIC) value was 0.754, while the lowest PIC value was 0. The mean genetic similarity index among the 80 Avena accessions was 0.545, ranging from 0.188 to 1.000. To assess the usefulness of ccSSRs in separating and distinguishing between haplome (genome) groups, we used ordination by canonical discriminant analysis and classificatory discriminant analysis. Although discriminant analysis separated the haplome groups unequivocally, it was up to 69% predictive of correctly classifying an individual plant whose haplome(s) is unknown in the case where it belonged to the A haplome group, 75% where it belonged in the AC group, and almost 80% where it belonged in the ACD group. The analysis of genetic similarity showed that diploid species with the A haplome were more diverse than other species, and that the species with the As haplome were more divergent than other diploid species with the A haplome. Among the species with the C haplome, A. clauda was more diverse than A. eriantha and A. ventricosa. In the cluster analysis, we found that the Avena accessions with the same genomes and/or belonging to the same species had the tendency to cluster together. As for the maternal donors of polyploid species based on this maternally inherited marker, A. strigosa served as the maternal donor of some Avena polyploidy species such as A. sativa, A. sterilis and A. occidentalis from Morocco. A. fatua is genetically distinct from other hexaploid Avena species, and A. damascena might be the A genome donor of A. fatua. Avena lusitanica served as the maternal parents during the polyploid formation of the AACC tetraploids and some AACCDD hexaploids. These results suggested that different diploid species were the putative A haplome donors of the tetraploid and hexaploid species. The C genome species A. eriantha and A. ventricosa are largely differentiated from the Avena species containing the A, or B, or D haplomes, whereas A. clauda from different accessions were found to be scattered within different groups. Wei-Tao Li and Yuan-Ying Peng have contributed equally to this paper.     

Identification of genomic constitutions of <Emphasis Type="Italic">Oryza</Emphasis> species with the B and C genomes by the PCR-RFLP method

Oryza officinalis complex is the largest and the most complicated group in the genus Oryza L., consisting of about ten species with the B, C, BC, CD, and E genomes. Taxonomy and identification of the species, particularly those with the B, C and BC genomes, are difficult due to the similar morphology and overlapping distribution of some species. The difference in ploidy levels of some species adds more complexity. In the present study, we surveyed 64 accessions of rice germplasm in the O. officinalis complex using RFLP analysis of PCR-amplified Adh genes in addition to chromosome counting. The results confirmed that all O. rhizomatis accessions are diploids with the C genome, whereas all O. minuta accessions are tetraploids having the BC genome. However, both diploid and tetraploid forms were found for the accessions identified in the genebank as O. officinalis, O. punctata and O. eichingeri. The tetraploid form of O. officinalis with the BC genome is exclusively distributed in India and has been described as O. malampuzhaensis. The tetraploid form of O. punctata which has been called O. schweinfurthiana by some workers was found to be as widely distributed as its diploid form in Africa. It is noteworthy that two accessions that had been determined as tetraploid O. officinalis were actually belonging to a species with the CD genome (O. latifolia). Our results promote a better understanding of the genomic constitutions of many accessions in the O. officinalis complex and correct determination of the genebank material, which serves as an important basis of germplasm cataloguing for further research and utilization.     

Relationships of Vigna unguiculata (L.) Walp., V. vexillata (L.) A. Rich. and species of section Vigna based on isozyme variation

Summary Isozyme variation in 25 accessions of wild and cultivated Vigna unguiculata, 49 accessions of seven wild species belonging to section Vigna, and 11 accessions of V. vexillata (subgenus Plectrotropis) was scored at 17 putative loci to assess genetic relationships within and among species. The wild species selected for this study are among those which carry important agronomical traits useful in cowpea (V. unguiculata) breeding programs. Allelic frequencies were calculated and Nei's genetic distances were obtained. Low levels of intraspecific variation were observed for V. heterophylla, V. luteola and V. racemosa, whereas the other species showed a higher polymorphism. Vigna unguiculata possessed intraspecific genetic distances comparable to those previously found by other authors. Most of the isozyme variation was apportioned among species. Although V. luteola and V. marina had an interspecific genetic distance resembling the range observed at intraspecific level, all the other species showed very high interspecific distances. Vigna unguiculata was relatively closer genetically to V. vexillata than to the species belonging to section Vigna.Abbreviations AUS Australia - BDI Burundi - BRA Brazil - BWA Botswana - CAF Central African Republic - GHA Ghana - CMR Cameroon - COG Congo - RI Costa Rica - EGY Egypt - ETE Ethiopia - GAB Gabon - GRC Greece - ITA Italy - KEN Kenya - MOZ Mozambique - NER Niger - NGA Nigeria - PAN Panama - RWA Rwanda - TCD Chad - TZA Tanzania - ZAF South Africa - ZAR Zaire - ZMB Zambia     

Variation in resistance to the cabbage aphid ( Brevicoryne brassicae) between and within wild and cultivated Brassica species

Seven Brassica species were evaluated for their resistance to the cabbage aphid, Brevicoryne brassicae, in a series of field experiments. Four wild Brassica species, two 8 chromosome species with similarities to the B genome of Brassica nigra (Brassica fruticulosa and Brassica spinescens) and two 9 chromosome species containing the C genome (Brassica incana and Brassica villosa) were identified as possessing consistently high levels of antibiosis mediated resistance to B. brassicae. None of the species were shown to possess consistently high levels of antixenosis resistance. In more detailed glasshouse experiments one B-like genome species, B. fruticulosa, showed considerable variation between accessions collected from different sites for resistance to B. brassicae. In addition, individual accessions of one A genome species (Brassica rapa) and one C genome species (Brassica alboglabra) were shown to be highly variable in their resistance to B. brassicae, some plants of each accession being highly resistant and others very susceptible. The implications of the variability in resistance to B. brassicae within wild Brassica species for exploitation in Brassica breeding programmes are discussed.     

Assessment of Genetic Diversity in Oil Palm (Elaeis guineensis Jacq.) using Restriction Fragment Length Polymorphism (RFLP)

A total of 359 accessions of oil palm (Elaeis guineensis Jacq.) originating from 11 African countries (Nigeria, Cameroon, Congo DR, Tanzania, Angola, Senegal, Sierra Leone, Guinea, Ghana, Madagascar and Gambia) were characterized using the RFLP method using the standard Deli dura as the check. Genomic DNA from each sample was digested using five restriction enzymes and hybridized with four oil palm cDNA probes. Data were analyzed using Biosys-1 computer software to calculate the genetic variability parameters. In general, all the collections exhibited higher levels of diversity than the standard variety, Deli dura. The standard variety, Deli dura, lost 36 alleles as compared to the natural populations indicating a reduction in genetic variability. Material from Nigeria showed the highest mean number of alleles per locus (1.9) and percentage of polymorphic loci (67.2%). These findings, combined with others, suggest that Nigeria may be the center of diversity of wild oil palm. It further suggests that oil palm natural populations maybe possessing adequate genetic variability that are potentially useful for improvement programs.     

Characterization of Vitis germplasm using random amplified polymorphic DNA markers

Summary An analysis of the amplification fragments polymorphism of DNA coming from different accessions of germplasm belonging to species and cultivars of the genus Vitis, was carried out using 40 primer decamers of arbitrary sequence. The RAPD profiles showed a great intraspecific diversity. In many cases a single primer produced a unique pattern for each species. A phylogram tree based upon presence/absence data of the principal DNA bands divided the species according to their geographical origins. The intraspecific polymorphism of DNA fragments was not sufficient for an unambiguous identification of Vitis vinifera cultivars but the RAPD profiles turned out to be highly reproducible. The high capacity of this technique to generate DNA markers offers a new possibility for the study of the genetic relationships in the genus Vitis.Abbreviations PCR Polymerase chain reaction - RAPD Random amplified polymorphic DNA     

Genetic identity and relationships of Iranian apple (Malus?×?domestica Borkh.) cultivars and landraces, wild Malus species and representative old apple cultivars based on simple sequence repeat (SSR) marker analysis

In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25 alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics, gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major players in apples’ domestication and transfer from Central Asia to the western countries.     

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 among perennial and annual Cicer species growing in Turkey as revealed by allozymes

Allozyme polymorphisms were used to assess genetic variation and relationships among ten Cicer species (annuals and perennials) growing in Turkey. Using seven enzyme systems, 12 putative scorable loci were detected and surveyed for polymorphism in an accession collection including wild and cultivated forms. Variation was generally low within accessions and species, but common between species. Cluster analysis based on the pairwise genetic distance coefficients among accessions and species using UPGMA revealed two species clusters; one includes three perennials (C. montbretii, C. isauricum and C. anatolicum) and the other contains six annuals (C. pinnatifidum, C. bijugum, C. judaicum, C. echinospermum, C. reticulatum and C. arietinum) and one perennial species (C.incisum). Grouping obtained in allozyme analysis appears to be consistent with the classification these species into three sections. However, contrary to relationships obtained in previous studies, three perennial species from section Polycicer were relatively distant to the group containing annuals. One perennial species, C. incisum from section Chamaecicer, clustered with annuals showing a close similarity. The grouping of six annual species was consistent with the previous reports of relationships. The relationships deduced between perennials and annuals appear to shed light on the evolution of annual habit from perennial habit.     

Genetic diversity of <Emphasis Type="Italic">rbc</Emphasis>L gene in <Emphasis Type="Italic">Elymus trachycaulus</Emphasis> complex and their phylogenetic relationships to several Triticeae species

Elymus trachycaulus complex species are known for their morphological variability, but little is known about their genetic basis. The phylogenetic relationships among the E. trachycaulus complex, and their systematic relation to other species in Triticeae remain unknown. Nucleotide diversity of ribulose-1,5 bisphosphate-carboxylase (rbcL) gene in E. trachycaulus complex species and several other Triticeae was first characterized and compared. A primary conclusion of the present study is that nucleotide diversity for rbcL gene in E. trachycaulus species was detected with the estimates of nucleotide diversity θ = 0.00039 and π = 0.00043. The estimate of nucleotide diversity in rbcL gene for species with different genome constitution here ranged from 0.00099 (π) and 0.00099 (θ) for the species with Ns genome to 0.00226 (π) and 0.00291 (θ) for the species with St genome. The phylogenetic relationships of these species were assessed using these rbcL sequences. A total of 47 variable positions including 19 parsimony-informative sites were detected among 24 accessions of 18 species/subspecies. The species with St, H/I and Ns genomes well separated from each other, and formed a three distinct clades with higher bootstrap values support for both Parsimony and NJ analyses. The St genome containing species is sister group of H/I genome containing species. Our result confirms that Pseudoroegneria is the maternal genome donor to these Elymus species studied here, regardless of their distribution. Elymus trachycaulus complex are more related to each other than to E. glaucescens, E. patagonicus, and E. solandri. This study suggested that Elymus species with StH genomes may form from multiple closely related sets of donors.