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Understanding the adaptive mechanism of trees to climate change and effective management of genetic resources necessitate a comprehensive knowledge of the relationship between environmental factors and their adaptive power. This study focuses on the endangered Moroccan endemic tree, Argania spinosa L., known for its remarkable adaptive power in the Mediterranean climate and heavily impacted by climate change. Through genomic scans along a latitudinal gradient, we aimed to identify genomic regions associated with convergent or divergent selection by searching the genome for outlier loci demonstrating high population differentiation. Variation of dominant markers (Amplified Fragment Length Polymorphism) was correlated with variation of environmental factors to discern signals of natural selection in 13 natural populations of Argania spinosa L. along a latitudinal transect.Genotyping of 130 individuals with 477 AFLP markers revealed six outlier loci exhibiting elevated population differentiation values within argan forests. The BayeScan v2.1 software was used to detect outlier loci, and the (MLM) method strongly associated these loci with at least five environmental factors, particularly bioclimatic variables. Notably, all outlier loci exhibited significant correlations with Soil Moisture, with additional associations with Temperature, Precipitation, Landforms, and Soil Type, influencing the local adaptation of Argania spinosa L.The outlier AFLP loci may not be the direct targets of natural selection, but locate closely to genes that are potential involved in local adaptation. Consequently, further investigations are imperative to validate these candidate loci. This research underscores the significance of considering bioclimatic variables, especially Soil Moisture, in understanding the local adaptation of Argania spinosa L. amid climate change in Morocco.

Tomato Solanum lycopersicum L. is one of the main vegetable crops, accessions and cultivars of which are characterized by a low level of genomic polymorphism. Introgressive tomato breeding uses related wild Solanum species to improve cultivars for stress tolerance and fruit quality traits. The aim of this work was to evaluate the genome variability of 59 cultivars and perspective breeding lines of S. lycopersicum and 11 wild tomato species using the AFLP method. According to the AFLP analysis, four combinations of primers E32/M59, E32/M57, E38/M57, and E41/M59, which had the highest PIC (polymorphism information content) values, were selected. In the process of genotyping a collection of 59 cultivars/lines of S. lycopersicum and 11 wild tomato accessions, the selected primers revealed 391 fragments ranging in size from 80 to 450 bp, of which 114 fragments turned out to be polymorphic and 25 were unique. Analysis of the amplification spectra placed wild tomato accessions into separate clades. Sister clades included cultivars of FSCV breeding resistant to drought and/or cold and, in part, to late blight, Alternaria, Septoria, tobacco mosaic virus and blossom end rot, as well as tomato accessions not characterized according to these traits, which suggests that they have resistance to stress factors. In accessions of distant clades, there was clustering on the basis of resistance to Verticillium, cladosporiosis, Fusarium, tobacco mosaic virus, gray rot, and blossom end rot. The combination of accessions according to their origin from the originating organization was shown. The primer combinations E32/M59, E32/M57, E38/M57 and E41/M59 were shown to be perspective for genotyping tomato cultivars to select donors of resistance to various stress factors. The clade-specific fragments identified in this work can become the basis for the development of AFLP markers for traits of resistance to stress factors.

It is necessary to regard the biodiversity of carrot as a genetic source of useful and indispensable components for the human diet. Amplified fragment length polymorphism (AFLP) markers were used to discriminate eight carrot genotypes with different root colors. With the combination of enzymes Tru9I, PstI, and three sets of primer pairs corresponding to adapters joint to the restricted sites, 92 loci were produced, including 60 polymorphic ones. Each of the three primer sets showed high efficiency, according to estimations of PIC (0.34, 0.34, and 0.41), D (0.36, 0.67, and 0.67), Rp (5.5, 11.3, and 15), and HE (0.32, 0.49, and 0.49). The genetic distances were calculated using values of Nei's coefficient. The most genetically similar were Chantenay Coeur Rouge and Colmar a Coeur Rouge at a distance of 0.12, whereas the most distant were Saint Valery and Purple Dragon at the highest distance of 0.34. Confirming its genetic identity, Purple Dragon and Gelber Goliath with purple and yellow roots were the most detached varieties from others at distances of 0.23–0.34 and 0.23–0.28, respectively. Male sterile Berlicum breeding accessions were well distinct from other orange-colored varieties at the highest distance of 0.30 from Deep Purple F1. Slight modifications including the facilitation of gel staining enables the wide use of the AFLP method for genetic diversity assessment in carrot breeding accessions. [ABSTRACT FROM AUTHOR]

The current study is the first worldwide to assess the genetic diversity of Kadaknath poultry using amplified fragment length polymorphism (AFLP) markers. Out of total 96 accessions, four were outliers and 92 were Kadaknath accessions of which 30 were males, 62 were females. Of these, 74 were jet black, 7 penciled and 11 were golden feather color type of Kadaknath. High level of polymorphism (23.94%) was observed in 387 loci amplified using six AFLP primer combinations. The Jaccard's similarity coefficient ranged from 0.211 to 0.754 with an average dissimilarity of 0.517. Based on the neighbor-joining method of clustering, all accessions were clustered into seven major clusters which were not consistent with their respective geographical locations. The mean values of effective multiplex ratio, polymorphic information content, resolving power and marker index were 15.16, 0.38, 9.87 and 5.85 respectively. Further, the high log-likelihood score was produced when the number of populations (K) was set at 7 while carrying out the population STRUCTURE analysis, which was also congruent with clustering analysis based on genetic diversity. The extent of genetic diversity detected in this study could be used for germplasm selection and developing conservation strategies of pure breed of Kadaknath. [ABSTRACT FROM AUTHOR]

The present study aimed to characterize the genetic structure of Artemisia eriantha Ten. and the diversity of the rhizosphere microbiota. Plant leaves and rhizosphere soils were sampled from three areas of Central Italy, namely Monte Corvo, Monte Portella (both from the Gran Sasso massif), and Monte Focalone (Majella massif). The plant samples were subjected to genetic structure analysis by amplified fragment length polymorphism (AFLP) markers. The microbiota from the rhizosphere soils was investigated by 16S rRNA gene metabarcoding. The within and among population variability was typical of outbreeding species. The AFLP polymorphisms revealed a marked closeness among plant populations collected in Monte Focalone and Monte Corvo, despite the geographical proximity of the latter with Monte Portella, a result confirmed by cluster, STRUCTURE, and discriminant analyses. 16S rRNA gene metabarcoding showed higher values of diversity for Monte Corvo (H, 5.7; Chao1, 445) and Monte Focalone (H′, 5.57; Chao1, 446) than Monte Portella (H′, 5.3; Chao1, 275). At the phylum level, the communities were mainly represented by Proteobacteria, Actinobacteria, and Acidobacteria (>10%). At the genus level, the Monte Focalone and Monte Corvo microbiotas were closer than Monte Portella, thus confirming the results from the plant communities. The findings provided evidence for the first time of an association between the Artemisia eriantha plant and microbiota communities. The relevance of the results in terms of biodiversity and the conservation strategies of plant and microbiota communities in the Central Apennines are discussed. [ABSTRACT FROM AUTHOR]

Being difficult to regenerate and maintain the seeds, the oleaginous bottle gourd was investigated using nine agromorphological traits and 31 amplified fragment length polymorphism (AFLP) markers. Specifically, the study was conducted to determine the intra-specific variability of a total of 173 accessions, which were identified from five agro-ecological regions from Côte d'Ivoire (Centre, East, North and South). Then, the genetic diversity and relationships within accessions were studied using AFLP markers. This characterization using both morphological and AFLP markers was realized in order to ultimately build a reliable core collection. The discriminant analysis, using nine quantitative traits, reveals plant length and seeds number per fruit as discriminating characteristics. From the accessions used for the agromorphological study, 148 were able to be differentiated by the AFLP markers. A range of 52 to 113 bands were amplified per primer combination. As revealed by the analysis of molecular variance (AMOVA), 28% of the total variation resides among accessions and 72% occurs within populations. The AMOVA computed in order to differentiate cultivars, displayed the same trends when no prior grouping of accessions was considered. The differentiation within cultivar (97%) was more than that, among cultivars (3%). Tree topologies inferred by neighbour-joining analysis reflected no clear cut off grouping. To group accessions, we used a Bayesian clustering analysis which exhibited two clusters. Using the informativeness of the primer combinations analysed in the present study, an orientation was given for the choice of the accessions which would be used to build a core collection. [ABSTRACT FROM AUTHOR]

Breeds can be easily identified using molecular tools based on genomic architecture of breed within a species. Moreover, in developing countries like Pakistan where the danger of genetic erosion is a serious threat due to uncontrolled crossbreeding, the application of such tools is promising for breed identification and conservation. Thus, the current research was planned to prepare AFLP based genetic markers for distinction of Red Sindhi cattle from crossbred population. In current study, 50 and 48 unrelated (males as well as females) were sampled for Red Sindhi and crossbred cattle populations, respectively. AFLP method was used to fetch prospective molecular markers present only in Red Sindhi however, lacking in crossbred and vice versa. The analysis generated eleven markers that were translated to single nucleotide polymorphism markers for genotyping. These markers were used for allelic variation analysis in both sampled populations. Moreover, single selected markers generated an identification probability of 0.800 while a probability for misjudgment of 0.313 for Red Sindhi cattle. However, the combination of three markers yielded a probability for judgment of 0.941 while a probability of misjudgment was 0.413. The study yielded panel of AFLP markers for identification of Red Sindhi that can be used as breed purity test to discriminate between Red Sindhi and crossbred population. [ABSTRACT FROM AUTHOR]

AFLP markers were used to build a core subset in 144 accessions of the United States Potato Genebank (USPG) ex situ collection of the species formerly known as Solanum phureja (now reclassified as Solanum tuberosum L. subsp. andigenum). A core subset aims to sample the minimum number possible of non-redundant germplasm units capturing the maximum diversity of the entire collection. Characterization and trait evaluation of a core subset is expected to be easier and more effective when compared to the entire germplasm collection. In this study 1534 polymorphic AFLP markers were generated and demonstrated to be useful to determine genetic relationships in the materials used. All the accessions were clearly discriminated from each other with genetic similarity levels ranging from 62 to 89%, and no duplicate germplasm samples were detected. To create the core subset, the presence of the AFLP marker was considered as the genetic trait to retain and the selection of accessions was determined by their rankings on the number of most markers added to the core. The results of this selection process revealed that the 9 top-ranked accessions of phureja, when combined, achieved the benchmark of capturing 85% of the markers detected in the complete collection. Further selection to increase the percentage of marker capture added 17 accessions with unique marker contributions which resulted in a final core subset of 26 accessions capturing 96% of the marker diversity. A Principal Component analysis determined that spatial distribution of diversity in the core was a proportional sampling of the entire diversity of the collection validating the selecting approach used. A review of the public database for valuable traits for the USPG phureja germplasm revealed that the core subset also included accessions with desirable pest/disease resistances and stress tolerances (in 25 out of the 30 traits reported in the database). The USPG expects this core subset would create opportunities for facilitating evaluation and research by using a reduced set of germplasm units with nearly all the diversity of the entire set. [ABSTRACT FROM AUTHOR]

It is necessary to regard the biodiversity of carrot as a genetic source of useful and indispensable components for the human diet. Amplified fragment length polymorphism (AFLP) markers were used to discriminate eight carrot genotypes with different root colors. With the combination of enzymes Tru9I, PstI, and three sets of primer pairs corresponding to adapters joint to the restricted sites, 92 loci were produced, including 60 polymorphic ones. Each of the three primer sets showed high efficiency, according to estimations of PIC (0.34, 0.34, and 0.41), D (0.36, 0.67, and 0.67), Rp (5.5, 11.3, and 15), and HE (0.32, 0.49, and 0.49). The genetic distances were calculated using values of Nei’s coefficient. The most genetically similar were Chantenay Coeur Rouge and Colmar a Coeur Rouge at a distance of 0.12, whereas the most distant were Saint Valery and Purple Dragon at the highest distance of 0.34. Confirming its genetic identity, Purple Dragon and Gelber Goliath with purple and yellow roots were the most detached varieties from others at distances of 0.23–0.34 and 0.23–0.28, respectively. Male sterile Berlicum breeding accessions were well distinct from other orange-colored varieties at the highest distance of 0.30 from Deep Purple F1. Slight modifications including the facilitation of gel staining enables the wide use of the AFLP method for genetic diversity assessment in carrot breeding accessions.

Abstract Background In the present investigation, two genera of family Labiatae (genus Origanum and genus Thymus including their available species in Egypt) were analyzed genetically on DNA level using amplified fragment length polymorphism (AFLP) markers. Four selective primer combinations ( E-AGC/M-CAA, E-AGC/M-CAC, E-AGG/M-CTC, and E-ACC/M-CAT ) were used to detect genetic variations (polymorphisms) within and between the studied plant species of each genus and with their cultivated relatives. Results A total of 193 amplified fragments were obtained overall primer combinations with a disparity in the number of bands for each primer combination. The primer combination E-AGG/M-CTC exhibited a large number of amplicons (67) compared to the other primers with polymorphism percentage 69%. The polymorphism information content (PIC) was calculated for the four primer combinations showing a very high values ranging between 0.98 and 0.99. On the other hand, Thymus species (Thymus vulgaris, Thymus capitatus L., and Thymus decassatus Benth.) exhibited a total number of 171 amplicons for all primer combinations with an average of 42 bands. The primer combination E-AGG/M-CTC produced the largest number of bands (62 bands) with polymorphism percentage 35%, even though the primer combination AGC/M-CAA was more efficient to give high polymorphisms within Thymus species where it resulted in a total of 35 bands with polymorphism percentage 63%. The PIC values were calculated ranging from 0.96 to 0.99. Conclusion One can conclude that AFLP technique was informative and efficient technique to give a good coverage of Origanum and Thymus genomes. Furthermore, it was helpful to elucidate the genetic variations and phylogenetic relationships within the studied species as a basis for further studies on these genera and related species.

Abstract The genus Rubus, from the family ofRosaceae Juss, has about 750 species worldwide, of which 8 species and 5 hybrids have been reported from Iran. The present study was conducted to evaluate the genetic diversity of 21 populations of 6 species of Rubus from different parts of Golestan province using 9 AFLP primer combinations. Excel and Pop Gen software were used for data analysis. Similarity matrix and cluster analysis were used by PAST software. The dendrogram was plotted based on unweighted pair group method with arithmetic average (UPGMA), using Jaccard's similarity coefficient. The results showed that eight out of nine selected primer combinations had appropriate polymorphic primer combinations. M160-E110 with 0.203 had the highest genetic variation among all used markers. All selected primer combinations found 505 position and 277 loci locations. Based on the results of the dendrogram, the studied populations were divided into two groups. Based on the results of the dendrogram, the studied populations were divided into two groups and the Caspian-Irano-Turanian populations were partially separated from the Caspian populations. According to the results of correlation analysis, the highest number of markers were related to traits of petiole length, terminal leaflet length, lateral leaf length, inflorescence length, lateral leaf width, and peduncle length. Results showed that AFLP marker was highly efficient in the separation and isolation of populations of species of Rubus species in this study.

Persimmon (Diospyros kaki L.) belongs to the family Ebenaceae known as the Japanese persimmon kaki. This crop was introduced in the Highlands in Central and East Java-Indonesia. A genetic analysis of a small sample of accessions was conducted using the Amplified Fragment Length Polymorphism (AFLP) method with IRDye700 labelled Pst1 (P11-700) and Mse1 restriction enzymes and seven primers combinations (M48, M49, M50, M51, M53, M55, and M58). The analysis resulted in a set of 441 bands, of which 117 were monomorphic and 324 polymorphic. The average percentage of polymorphic bands was 73.4%. The four persimmon accessions were genetically distinguished into three groups, with a high genetic diversity among them, while accessions B (Batu) and D (Dampit) show little differences in their profiles. [ABSTRACT FROM AUTHOR]

Genetic marker studies can assist restoration practice through selection of seed sources that conserve historical levels of gene diversity and population genetic differentiation. We examined genetic variation and structure within and among mainland and island populations of Elymus glaucus, a perennial bunchgrass species native to western North American grasslands that is targeted for grassland restoration. Island populations of E. glaucus represent sensitive sites and potentially distinctive seed sources for reintroduction, and little is known of their genetic composition. Genetic diversity and structure were estimated using amplified fragment length polymorphism markers for 21 populations and 416 individuals distributed across two coastal California mainland locations and three California Channel Islands. Eight primer combinations resulted in 166 markers, of which 165 (99.4 %) were polymorphic. The number of polymorphic bands was significantly greater among mainland populations relative to island sites, and locally common alleles were present for each sampled island and mainland location. Population structure was high (62.9 %), with most variation (55.8 %) distributed among populations, 7.1 % between mainland and island locations, and the remainder (37.1 %) within populations. Isolation by distance was only apparent among islands. Using marker data to recommend appropriate seed sources for restoration, E. glaucus seeds are best derived within islands with collections representing a large number of individuals from matching environments. Given the limited gene flow and prior evidence of adaptive divergence among populations of this species, regional collections are recommended in all cases to maintain diversity and to avoid long-distance introductions of highly differentiated plant material.

Abstract Background The banana weevil Cosmopolites sordidus (Germar) is a major production constraint of bananas and plantains (Musa spp.) in the world. Differences in damage levels and pesticide response across regions led to the postulation that there might be considerable variation between banana weevil populations (biotypes) with varying levels of virulence. One of the most sustainable options for banana weevil control is the use of host plant resistance. While new resistant varieties are being developed through both conventional crossbreeding and biotechnology, there is a need to assess the genetic variation of banana weevil populations from eastern, central, southern, southwestern and midwest regions of Uganda to determine whether there are biotypes with different virulence levels. This would help guide new control strategies to target all the possible biotypes. The amplified fragment length polymorphism (AFLP) technique was used to analyze population genetic diversity using four primer combinations (EcoRI/MSeI). Results Analysis of molecular variance results presented no evidence to support significant genetic variability among the banana weevil populations from eastern, central, southern, southwestern and midwest regions. Practically, all the genetic variation was found to reside within populations (97% for sites and 98% for regions), with only approximately 3% and 2% residing among populations of sites and regions, respectively. Conclusions and recommendations AFLP markers clustered the banana weevils into two distinct populations consequently supporting the hypothesis of possible presence of banana weevil biotypes in Uganda. However, attempts should be made to make follow-up studies on the seemingly unique population of eastern Uganda using more robust molecular techniques to establish whether the eastern Uganda population constitutes a different biotype.

Useful genetic diversity found in wild potato germplasm is important for progress in potato breeding and science. An effective way to maximize its utilization is through characterization of ex situ collections. For example, marker-based core subsets from large collections are an effective strategy to accelerate evaluation, utilize germplasm, and enhance cost-effectiveness. This project used AFLP markers to create a core subset for the US Potato Genebank's collection of S. demissum. This species from Mexico and Guatemala is known for excellent levels of late blight resistance and frost tolerance. A total of 149 accessions with diverse geographic origin were characterized with 1403 AFLP markers; these markers were effective on determining genetic associations among the accessions. For the core subset, the AFLP loci were considered as traits, with the presence of the marker as the required state to include in a core. The results of the analyses identified that 10 of the accessions of S. demissum captured 83% of all the markers detected in the whole collection. The inclusion of 28 additional accessions, which had between 1 to 5 unique markers, resulted in a core set of 38 accessions that captured 96% of all the marker diversity. We expect this can benefit the genebank and the potato community by opening opportunities for research, trait screenings, and marker association studies. [ABSTRACT FROM AUTHOR]

The diversity of Phakopsora pachyrhizi populations has often resulted in the selection of virulent pathotypes following the release of rust-resistant cultivars. Thus, knowledge of the pathogenicity and variability of P. pachyrhizi specie, coupled with an understanding of its biology and host-pathogen interactions, is essential for better comprehension of the evolution and rapid adaption of the pathogen. Such comprehension can be useful for genetic breeding programs and other research areas. Therefore, this study aimed to assess the genetic variability and virulence among P. pachyrhizi mono-uredinial isolates obtained from field samples collected in Brazil during the period from 2007 to 2012 by comparing the sequences of Internal Transcribed Spacer (ITS) regions and AFLP markers and analyzing the responses of differential soybean genotypes. The polymorphisms among the AFLP markers (locally) and ITS sequences (globally) demonstrated the high genetic diversity of this pathogen. Phenotypic analysis revealed the presence of at least 16 different pathotypes present in soybean fields in Brazil. The most effective resistance gene was Rpp5 (PI 200487), followed by Rpp4 (PI 459025) and Rpp2 (230970). This study represents the first report on the virulence and molecular characterization of a collection of P. pachyrhizi mono-uredinial isolates, which might represent different races occurring in Brazilian fields in the period from 2007 to 2012. [ABSTRACT FROM AUTHOR]

The genetic diversity among ninety five accessions of winged bean (Psophocarpus tetragonolobus (L.) DC.) belonging to six countries of African and Asiatic origin was detected by employing amplified fragment length polymorphism (AFLP) and internal transcribed spacer (ITS) of nuclear ribosomal DNA markers. A medium to low-level of genetic diversity exists among the accessions of P. tetragonolobus. Association between the AFLP markers and flower, pod and seed traits: days to 50% flowering (DFW), pod length (PDL), pod width (PDW), green pod length (GPL), number of pods per plant (PDSP), number of seeds per pod (SDPD), 100 seed weight (SWT) and seed-oil content (SOC) was carried out by employing the mixed linear model (MLM) based kinship matrix (K-model). Traits like SOC and PDW were found to be strongly associated with AFLP markers. Population structure analysis among the genotypes identified five discrete sub-populations among the studied African and Asiatic lines of P. tetragonolobus. [ABSTRACT FROM AUTHOR]

The Asian chestnut gall wasp, Dryocosmus kuriphilus, is an invasive pest causing significant damage to chestnut trees (Castanea spp., Fagaceae). Originating from China, it has recently invaded a wide range of regions in Europe and North America. Understanding the population genetic structure of important invasive pests is very useful for improving the knowledge concerning routes of expansion and colonizing capacity. Despite its economic importance, limited attention has been given to D. kuriphilus origin and spread, or to its genetic structure. In this study, D. kuriphilus populations sampled in eight European countries were screened using both mitochondrial (cytochrome c oxidase subunit 1; COI) and nuclear (internal transcribed spacer 2; ITS2) sequences, and Amplified Fragment Length Polymorphism (AFLP) markers. The molecular markers COI and ITS2 highlighted the presence of a single haplotype in all the studied populations. The recorded mitochondrial haplotype was identical to one of the most widespread haplotypes occurring in the native area (China). AFLP results indicated that D. kuriphilus individuals belong to two genetically distinct clusters without any further geographic clustering. These results suggest that D. kuriphilus populations in Europe could be the result of a single introduction of a Chinese founder population characterized by two genetically distinct lineages that subsequently spread rapidly across Europe. However, the possibility that populations originated from multiple introductions of the same Chinese mitochondrial haplotype cannot be excluded. The reported results provide useful information concerning this invasive species, potentially facilitating integrated pest management. [ABSTRACT FROM AUTHOR]

Pomegranate (Punica granatum L.) is native to Iran with several ecotypes which have been adapted to various climatic conditions and diseases. Although it is one of the important exported fruits, there is not a precise identification criteria to determine the authenticity of genetic inheritance and proprietary rights in the country. In the present study the genetic relationships of 47 pomegranate genotypes, including 9 cultivated genotypes (from the collection of Yazd) and 38 wild genotypes (from Mazandaran, Gilan and Golestan provinces), were investigated with AFLP markers. Using 10 primer combinations, 825 bands were obtained of which 697 showed polymorphism. Among the primers, primer combination of M-CTT and E-ACG showed the highest number of bands (148) and primer combination of E-ACC, M-CTG produced the lowest number of bands (40). The average value for PIC was 0.21, while Average Marker Index (MI) was 17.33 that the highest one belonged to primer combination of M-CAC and E-AAG. Maximum genetic similarity belonged to Bahnamir with Shirin Kan Tehran samples and the minimum genetic similarity observed between Berenjestanak and Khosh Darreh. Principal component analysis showed that 57% of the total variance was explained by first three components. The identified primer combinations in this study could be used as a powerful tool for determination of genetic relationships between Pomegranate genotypes

The evaluation of morphological differences is a traditional method of evolutionary and pedigree relationship determination. It was particularly useful in maize, where phenotypic differences occur (e.g. colour, kernel type and kernel size) (Murariu et al., 2002). However, only molecular markers provide information that is independent of environmental influences or of plant development phase. Therefore, techniques of DNA analysis have become more and more important. Methods based on polymerase chain reaction - PCR - are used widely in research. One of the used methods is the RAPD method (Randomly Amplified Polymorphic DNA) (Beebe et al., 2000). Our aim was to determine the genetic variability existing among maize landraces coming from western part of Romania and to adapt a method for their distinguishing. The use of molecular characterization has allowed the study of diversity within these accessions and the investigation of genetic relationships among them, revealing a wide genetic diversity in this set of 60 accessions, having a highest genetic diversity; they belong to different groups and could be used as base populations for future breeding programs. [ABSTRACT FROM AUTHOR]

Information on genetic diversity among cultivars is critical in wheat improvement. In this work, heterogeneity within local and introduced cultivars of bread wheat grown in Syria was investigated using amplified fragment length polymorphism (AFLP) markers. The eight primer pairs were used to detect 177 polymorphic bands among the 21 cultivars resulting in an average of 22.13 (57.3%) polymorphic loci per primer pair. Major allelic frequency ranged from 0.50 to 0.75 with a mean 0.64, and estimated gene diversity was 0.45. Values of average polymorphic information content (PIC) for these markers were estimated to be 0.34. This low value might be attributed to the rigorous selection pressure aimed at cultivar purity and associated breeding practices. Dissimilarity values ranged from 0.32 to 0.66 with an average of 0.54, indicating that such techniques sample distinct genome regions. Three major subgroups of wheat cultivars were identified using the unweighted pair-group method with arithmetic means analysis (UPGMA), with all local cultivars falling into one cluster, which was confirmed by a principal component analysis (PCA). The narrow genetic diversity observed among Syrian wheat cultivars suggests the need of broadening the genetic base of wheat breeding materials, including local landraces. [ABSTRACT FROM AUTHOR]

Xanthosoma sagittifolium (L.) Schott originated from the American tropics. Domestication may have occurred in various places as this Araceae species is an important food source. It has been cultivated for many decades. In this study, Amplified Fragments Length Polymorphism (AFLP) markers were used to analyze the genetic relationships among 78 Ethiopian X. sagittifolium accessions, for conservation purpose. Cormels were collected from Bench-Maji, Kefa, Dawuro and Wolaita zones, representing four populations. The accessions belonged to either green (G) or purple (P) colored leaf and petiole accessions. Three different AFLP primer combinations resulted in 478 scorable bands, of which 99.2% were polymorphic. The mean Nei’s gene diversity (He) within populations was 0.35 while the G accessions featured higher He (0.38) than the P ones (0.35). The Nei’s gene diversity (He) at entire collection level was 0.38. The detected high genetic diversity may indicate the X. sagittifolium plants growing in the country may derive from diverse parental genotype stock elsewhere and/or there may be multiple introductions to the country. Low levels of genetic differentiation were detected among populations (Gst = 0.07) and between the G and P accessions (Gst = 0.02). Insignificant genetic and geographic correlation was revealed by Mantel test. Clustering analysis grouped 91% of the accessions together. Conservation and management of X. sagittifolium in the country should concentrate on maintaining high level genetic diversity within each population as well as at entire collection level through both ex situ and in situ conservation actions. [ABSTRACT FROM AUTHOR]

Amphibians are one of the most poorly studied groups of vertebrates in ecotoxicology and radioecology. The level of cytogenetic damage in the blood cells of tadpoles Rana arvalis Nilsson living on the territory of the Ukhta district of the village of Vodnyi in the Komi Republic, which is contaminated with technogenic radionuclides and heavy metals, is evaluated by “Comet assay”. It is shown that, in animals that develop in water bodies with high concentrations of radionuclides and heavy metals, the frequency of alkalilabile sites and single-strand break of DNA is higher than in the control area. No significant differences have been found when estimating the level of double-strand break of DNA. AFLP analysis indicates a weak genetic differentiation of the studied populations of amphibians. [ABSTRACT FROM AUTHOR]

Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P. tenuifolia populations. Twelve primer combinations of AFLP produced 310 unambiguous and repetitious bands. Among these bands, 261 (84.2%) were polymorphic. The genetic diversity was high at the species level: percentage of polymorphic loci (PPL) = 84.2%, Nei's gene diversity ( h ) = 0.3296 and Shannon's information index ( I ) = 0.4822. Between the two populations, the genetic differentiation of 0.1250 was low and the gene flow was relatively high, at 3.4989. The wild population (PPL = 81.9%, h = 0.3154, I = 0.4635) showed a higher genetic diversity level than the cultivated population (PPL = 63.9%, h = 0.2507, I = 0.3688). The results suggest that the major factors threatening the persistence of P. tenuifolia resources are ecological and human factors rather than genetic. These results will assist with the design of conservation and management programs, such as in natural habitat conservation, setting the excavation time interval for resource regeneration and the substitution of cultivated for wild plants. [ABSTRACT FROM AUTHOR]

Freshwater Pangasiid catfish species and hybrids are difficult to identify on the basis of morphological characteristics, especially for larvae and fingerlings. In this study, we identified genetic markers for Pangasiid catfish breeds, viz. Pagasianodon gigas, Pagasianodon hypophthalmus and their F1 and F 2 hybrids. Twenty primer comb inations were used to screen for specific amplified fragment length polymorphism (AFLP) markers. A total of 486 DNA bands were identified and 335 polymorphic bands were found to be segregated among these catfish types. The level of polymorphism detected using 20 different primer combinations ranged between 65.38-100%. Eleven distinct markers were found to be significantly associated with P. gigas (two markers), P. hypophthalmus (three markers), their F1 hybrid (three markers) and F2 hybrid (three markers). Using these markers, 100% of the individuals were accurately assigned to their correct species. These results demonstrate that AFLP markers can be used to genetically i dentify Pangasiid catfish species and hybrids.

According to the importance of studies of abiotic stress, present study was done in order to identify of molecular markers with significant association to flooding stress tolerance in barley. This study carried out using of AFLP markers and 40 barley genotypes. Generally 22 variables in both normal and flooded, eight characters including shoot dry weight, length, volume, wet weight, dry weight, leaf area, root diameter and density tolerance was assessed with six indicators (SSI, STI, GMP, TOL, YI and YSI). Seven primer combinations of EcoRI and MseI a total of 245 bands were produced, of which, 227 bands were polymorphic and had an average of 92.37 percent polymorphism. Three combinations E90-M160, E100-M160 and E90-M150 had higher values of genetic variation compared to other combinations and were more effective in distinguish of genotypes. Association analysis was performed using structure matrix and statistical models of GLM and MLM by using of TASSEL software for 22 variables. The MLM model in 5 percent probability level identified 87 markers related to evaluated traits. According to the results of association analysis in normal condition the highest of coefficient of determination was for E100M16027 with explanation of 32 percent of root diameter variation and for tolerance indices and stress condition the highest coefficient of determination were for E80M1501 and E100M15022 with 24 percent explanation of variation of GMP index and shoot dry weight respectively.

The amplified fragment length polymorphism (AFLP) technique was used to investigate the genetic relationship among somaclonal variants and cultivated varieties ofCereusat the molecular level. Samples oftortuosusandmonstruosusvarieties, as well as cacti with typical erect shoots,monstruosussomaclones, and somaclones with erect shoots were analyzed using six AFLP primer pairs. The highest value for genetic diversity was detected among themonstruosussomaclones. High identity values were detected among erect,monstruosus, andtortuosusvarieties as well as among erect andmonstruosussomaclones. The AFLP markers revealed divergences in thein vitrocultures and in the natural environment (in vivo), and also illustrated the potential of themonstruosusandtortuosusvarieties as well as theCereussomaclones for generating new varieties of ornamental value. [ABSTRACT FROM AUTHOR]

Background: Hypericum perforatum is one of the valuable medicinal plants in Iran that is used in treating human diseases likes mania, anxiety and depression. Objective : Iranian H. perforatum populations were gathered from deferent region of Iran and also their genetic diversity in company with the possible relationship between genetic diversity and geographical distribution were studied. Methodes: DNA was isolated by CTAB method from young leaves and double digested by EcoRI and Tru1I enzymes. Polymorphic DNA markers generated by DNA fingerprinting technique AFLP (Vos method) using 12 primers combinations. DNA fragments detected with silver nitrate staining according to Basam protocol. Results: Totally 235 bands were scored, that 97% of them were polymorphic. The PIC values ranged between 0.31 and 0.45 with mean of 0.38. The highest and the lowest levels of genetic similarity were 0.89 and 0.29, respectively. Cluster analysis using UPGMA method and DICE similarity coefficient indicated a high genetic diversity among H. perforatum populations. There was no relationship between genetic diversity and geographical distribution. Also for the all loci, the PC1 and PC2 explained 12.8% and 8.3% of the variation, respectively. Conclusion: Wide genetic diversity between Iranian H. perforatum pupulations provide applied information to performance of breeding programs and genetic resource management. Of course, investigation of amount of hypericin and hyperforin metabolites in these populations are requiring to selection paramount genotypes.

Traditionally, tetraploid Paspalum notatum was considered an obligate or a facultative apomict according to cytoembryological analyses. The degree of facultativeness was usually determined by the relative amount of mature ovules bearing aposporous or meiotic (sexual) embryo sacs, or both together. We established, through progeny tests conducted with the aid of AFLP markers, the degree of residual sexuality expressed in four selected biotypes. The results showed it to be substantially and significantly lower than predicted by previous embryological analyses for the same biotypes. Moreover, the lowest expression of residual sexuality was coincident with maximum flowering period. Seed development in facultative apomictic P. notatum shows a definite bias against meiotic embryo sacs.

An extremely endangered population of Viola uliginosa Besser at the classical locality of this taxon has been studied. The AFLP analysis was based on 18 specimens of V. uliginosa (about 10% of preserved individuals); additionally, two individuals of V. riviniana were included in the data set as the out group. A high genetical uniformity of the whole population (similarity indexes close to 1) was detected. It was not correlated significantly with the spatial distribution of the plants. The study serves as a basis for practical conservation measures and at the same time as a starting point for a more extensive research on the genetical variability of the species throughout its range.

The morphology of Calamagrostis canescens and C. stricta recorded in the Małopolska Upland (the vicinity of Zbijów Mały, ca. 10 km northeast of the town of Skarżysko-Kamienna, Central Poland) was examined due to intermediate individuals found in sympatric populations of these species. Both putative parents as well as individuals that appeared hybrid-like were found in an extensive, wet hay-meadow. Various vegetative and reproductive characteristics were studied to identify hybrids. Interestingly, Polish accessions of C. ×gracilescens exhibited some degree of morphological intermediacy but resembled C. stricta in spikelet morphology. Branching of the mid-culm, the number of nodes per culm, callus hair length and relative callus hair length are the best characters to distinguish the Polish C. ×gracilescens. AFLP analysis proved to be suitable for detecting recent hybridization events between C. canescens and C. stricta. Analysis of the Bayesian clustering analysis showed that C. ×gracilescens were subjected to gene flow from the C. canescens gene pool as well as from the C. stricta gene pool.

Thymus is a widely distributed genus in the Mediterranean region with several species endemic to the Iberian Peninsula. The genetic relationships among the 12 major Thymus taxa, T. albicans, T. caespititius, T. camphoratus, T. capitellatus, T. carnosus, T.lotocephalus, T. mastichina L. ssp. mastichina, T. pulegioides, T. villosus ssp. lusitanicus, T. villosus ssp. villosus, T. zygis ssp. sylvestris and T. zygis ssp. zygis, which occur in Portugal were assessed by AFLP (Amplified Fragment Length Polymorphisms) markers. A general agreement was found between the genetic relationships estimated by the AFLP markers and the accepted Thymus taxonomy based on morphological traits and essential oil content. The AFLP markers also supported suggestions for refinement of the taxonomy of this genus. [ABSTRACT FROM PUBLISHER]

Viola uliginosa (bog violet) is a declining species throughout its range due to - mostly anthropogenic - drying out of the wet habitats it occupies. Using AFLP markers, we aimed to estimate the genetic diversity in Polish populations, that may give an insight into the situation of plant populations facing rapid loss of natural habitats. Bog violet from several dispersed Polish populations is generally characterized by very low genetic diversity ( HT = 0.048), even lower than several other endangered violets; therefore, we suggest that it should preserve at least EN rank in the red lists/red data books. The mean gene diversity within all populations ( HS) was much lower than gene diversity ( GST) between populations (0.020 versus 0.583, respectively) which supports the prevalence of clonal propagation of the species (mainly by stolons) but may also point to some significance of autogamy in cleisto- and chasmogamous flowers. A high FST value and the Mantel test for all populations revealed significant isolation by distance. Geographically neighboring pairs of populations formed genetic clusters supported by all (in the case of two closest populations) or most statistical analyses applied. Special attention should be paid to the locus classicus of the species in Rząska, consisting of a small number of individuals, forming a genetically distinct group, revealing very low gene diversity ( Hj = 0.009) and the longest genetic distance to the remaining populations. Our results can contribute to planning future protection measures for the species at this and other locations. Genetic structure of the studied populations suggests local affinities of populations but does not generally support hypothesized recent continuity of V. uliginosa range along the river valleys of southern Poland; this view may, however, be altered with widening of the scope of studied populations and chosen molecular markers. [ABSTRACT FROM AUTHOR]

The conservation of plants in germplasm banks ensures the characterization and availability of these resources for future generations. The present study used DNA markers to obtain genetic information about germplasm collections of Lippia sidoides and L. gracilis, which are maintained in an Active Germplasm Bank (AGB). Genetic variability of samples in the AGB was assessed using 12 combinations of ampliied fragment length polymorphism (AFLP) primers (EcoRI/MseI). Twenty simple sequence repeat primers designed for L. alba were tested to determine their transferability in L. sidoides and L. gracilis. The AFLP markers generated 789 markers. The assessed loci exhibited a moderate Shannon diversity index (I = 0.42) in both species, suggesting that the conserved accessions possess an intermediate level of genetic diversity. Twelve microsatellite loci ampliied satisfactorily, and nine loci were polymorphic in each species. A total of 23, 22, and 36 alleles, with an average of 2.5, 2.4, and 3.27 alleles per locus were identiied for L. sidoides and L. gracilis accessions in the AGB, and Lippia sp sampled plants, respectively. Analyses of genetic structure permitted the identiication of three different groups using both sets of markers, of which two were representative of L. sidoides. The information generated in this study may help to create, expand, and maintain collections of these species and may assist in genetic-breeding programs. [ABSTRACT FROM AUTHOR]

Senecio pterophorus (Compositae) is a perennial shrub native to eastern South Africa that was introduced into the Western Cape in South Africa and Australia approximately 100 years ago and into Europe (Italy and Spain) more than 25-30 years ago. In this study, the aims were to unravel the putative sources of the introduced populations and identify the changes in genetic diversity after invasion using molecular markers and phylogeographic and population genetic analyses. We sampled the entire area of distribution for S. pterophorus extensively. Based on the results, three lineages were established along a latitudinal and climatic gradient in the native range (south, central, central/north) with high levels of admixture. Multiple, independent introductions occurred in the four invaded ranges. The central/northern lineage (humid climate) was the primary source for all of the invaded regions (with drier climates), although a secondary role was revealed for the southern lineage in the Western Cape and the central/northern lineage in Australia and Spain. The genetic diversity was slightly lower in the Spanish and Australian populations than that in the native populations. A variety of demographic and genetic processes affected the amount and structure of genetic diversity in the invaded areas, including multiple introductions and admixture (Western Cape, Australia and Spain) as well as pre-invasive hybridization (Italy). The patterns of dispersion support a hypothesis of rapid evolution of S. pterophorus after invasion in response to novel climatic conditions. [ABSTRACT FROM AUTHOR]

Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent. [ABSTRACT FROM AUTHOR]

Com objetivo de estudar diversidade genética e identificar marcadores associados à resistência ao míldio (Plasmopara viticola) e ao oídio (Uncinula necator), foram analisadas as cultivares de videira A 1976, CG 87746, CNPUV 154-27, Crimson Seedless, Gota de Ouro, Itália, Seyve Villard 12327 e Seyve Villard 12375. As análises de polimorfismo de comprimento de fragmento amplificado (AFLP) seguiram as etapas de digestão, ligação, pré-amplificação e amplificação. Efetuou-se a separação dos fragmentos amplificados em gel de 7% de poliacrilamida desnaturante (uréia 7M) e coloração com nitrato de prata. A similaridade foi estimada com base no coeficiente de Jaccard, e a agregação, por UPGMA. Foi gerada uma matriz de similaridade com bom ajustamento da agregação (r = 0,84). Os agrupamentos obtidos corresponderam à origem e classificação botânica das cultivares. Foram identificadas 15 marcas dissimilares associadas à resistência, sendo oito para míldio e sete para oídio.The grapevine cultivars A 1976, CG 87746, CNPUV 154-27, Crimson Seedless, Gota de Ouro, Itália, Seyve Villard 12327 and Seyve Villard 12375 were analyzed to establish the genetic relationship and to identify markers associated with resistance to downy mildew (Plasmopara viticola) and powdery mildew (Uncinula necator). The amplified fragment lenght polymorphism (AFLP) analysis comprise the steps of digestion, ligation, preamplification and amplification. The amplified fragments were separeted on a 7% denaturing polyacrylamide gel (7M urea) and silver stained. The similarity was estimated using Jaccard's coefficient and the clustering was estimated by UPGMA. A similarity matrix was generated with a good fit for aggregation (r = 0,84). The clusters corresponded to origin and botany classification of the cultivars. Fifteen markers were associated with resistance, eight for downy mildew and seven for powdery mildew.

The genus Phlomis is represented in the island of Crete (Greece, Eastern Mediterranean) by three species Phlomis cretica C. Presl., Phlomis fruticosa L., the island endemic Phlomis lanata Willd. and three hybrids Phlomis x cytherea Rech.f. ( P. cretica x P. fruticosa ), Phlomis x commixta Rech.f. ( P. cretica x P. lanata ) and Phlomis x sieberi Vierh. ( P. fruticosa x P. lanata ). This work describes (a) the profile of hybrids and parental species concerning their volatile compounds, (b) the suitability of ribosomal nuclear (ITS region), chloroplast ( trn H -psb A), and AFLP markers to identify hybrids and (c) their competence to characterize the different chemotypes of both hybrids and their parental species. The cluster analysis and PCA constructed from chemical data (volatile oils) suggest that there are three groups of taxa. Group IA includes P. cretica and P. fruticosa , group IB includes P. x cytherea , whereas group II consists of P. x commixta , P. x sieberi and P. lanata . Volatile compounds detected only in the hybrids P. x sieberi and P. x commixta correspond to the 3% of the total compounds, value that is much higher in P. x cytherea (21%). Neighbor-joining, statistical parsimony analysis and the observations drawn from ribotypes spectrum of ITS markers divided Phlomis species in two groups, P. lanata and the complex P. cretica / P. fruticosa . In contrast to the ITS region, the plastid DNA marker follows a geographically related pattern. Neighbor-Net, PCA and Bayesian assignment analysis performed for AFLP markers separated the genotypes into three groups corresponding to populations of P. cretica , P. fruticosa , and P. lanata , respectively, while populations of P. x commixta , P. x cytherea , and P. x sieberi presented admixed ancestry. Most of the P. x cytherea samples were identified as F1 hybrids by Bayesian assignment test, while those of P. x commixta and P. x sieberi were identified as F2 hybrids. Overall, high chemical differentiation is revealed in one of the three hybrids, which is likely related with niche variation. Moreover, molecular markers show potential to identify Phlomis taxa. [ABSTRACT FROM AUTHOR]

Neutral and selective processes can drive repeated patterns of evolution in different groups of populations experiencing similar ecological gradients. In this paper, we used a combination of nuclear and mitochondrial DNA markers, as well as geometric morphometrics, to investigate repeated patterns of morphological and genetic divergence of European minnows in two mountain ranges: the Pyrenees and the Alps. European minnows ( Phoxinus phoxinus) are cyprinid fish inhabiting most freshwater bodies in Europe, including those in different mountain ranges that could act as major geographical barriers to gene flow. We explored patterns of P. phoxinus phenotypic and genetic diversification along a gradient of altitude common to the two mountain ranges, and tested for isolation by distance ( IBD), isolation by environment ( IBE) and isolation by adaptation ( IBA). The results indicated that populations from the Pyrenees and the Alps belong to two well differentiated, reciprocally monophyletic mt DNA lineages. Substantial genetic differentiation due to geographical isolation within and between populations from the Pyrenees and the Alps was also found using rapidly evolving AFLPs markers (isolation by distance or IBD), as well as morphological differences between mountain ranges. Also, morphology varied strongly with elevation and so did genetic differentiation to a lower extent. Despite moderate evidence for IBE and IBA, and therefore of repeated evolution, substantial population heterogeneity was found at the genetic level, suggesting that selection and population specific genetic drift act in concert to affect genetic divergence. [ABSTRACT FROM AUTHOR]

Background: Bhutan is a small Himalayan country lying within the region considered to be the origin of citrus. Diverse citrus wild types grow naturally in different climates, elevations and edaphic conditions, but only mandarin is cultivated commercially. The first report of Huanglongbing (also known as greening disease) in Bhutan in 2003, and the threat it posed to the country's citrus orchards prompted the collection of mandarin germplasm from across the country. This paper describes the genetic diversity of mandarin accessions in Bhutan using amplified fragment length polymorphic (AFLP) markers. Results: Twenty three accessions of Bhutanese mandarin were analyzed using AFLP markers to assess the genetic variability that is believed to exist only in Bhutan and some parts of North East India and South China. Five primer pairs (E-ACA/M-CAG, E-ACG/M-CAT, E-ACC/M-CTT, E-AAG/M-CAA and E-ACA/M-CTC) were identified (based on the number and quality of polymorphic bands produced) and used for the analyses. A total of 244 bands were scored visually of which 126 (52%) were polymorphic with an average polymorphism information content of 0.95 per marker. A cluster dendrogram based on multiscale bootstrap sampling categorized twenty three accessions into two broad groups containing eight and 14 accessions, respectively. Group A consisted accessions (Tsirang1, Tsirang3, Sarpang1, Dagana4, Samtse4, Dagana1, and Trongsa2) from five districts (Tsirang, Sarpang, Samtse, Dagana and Trongsa) and their grouping was strongly supported by bootstrap analysis (B p-value = 96%, AU p-value = 86%). Cluster B consisted of 14 accessions divided into three sub-groups (1, 2 and 3). However, bootstrap value supported significantly for subgroup1 (containing accessions: Tsirang4, Sarpang5, and Tsirang2) and subgroup3 (with accessions - Zhemgang2, Zhemgang3 and Zhemgang4). Conclusion: This study indicates that Bhutanese mandarin germplasm collected from across the country are genetically diverse although the level of variability differed among the accessions assessed. The variation in genetic variability was observed irrespective of where the accessions were collected suggesting that phenotype and geographical location can serve a basis for future germplasm collection in Bhutan. Further, five primer pair combinations could separate 23 mandarins accessions considered in this study, suggesting that AFLP markers can be a useful tool for future identification. [ABSTRACT FROM AUTHOR]

Breeding efforts within Buxus have been limited, despite the great morphological and genetic variation within this genus. To evaluate the possibilities for creating novel cultivars through interspecific hybridisation within Buxus , we have made over 7500 interspecific crosses involving Buxus harlandii Hance, Buxus sempervirens L., Buxus microphylla Sieb & Zucc, Buxus balearica Lam., Buxus colchica Pojark and Buxus henryi Mayr. Germination of the resulting interspecific seeds was between 0% and 47% for some cross combinations. In total 4750 interspecific F1 seedlings were obtained. The hybrid nature of most seedlings could be proven using AFLP markers or flow cytometry. As expected, crosses at diploid level or tetraploid level were efficient. Moreover, our results showed that interploidy crosses (diploid × tetraploid) were also efficient. This study is the first in-depth exploration of the possibilities of interspecific hybridisation within Buxus . These results may become a valuable tool to create new Buxus cultivars with desirable traits. [ABSTRACT FROM AUTHOR]

Background: Interspecific hybridization is a useful tool in ornamental breeding to increase genetic variability and introduce new valuable traits into existing cultivars. The successful formation of interspecific hybrids is frequently limited by the presence of pre- and post-fertilization barriers. In the present study, we investigated the nature of hybridization barriers occurring in crosses between Kalanchoë species and evaluated possibilities of obtaining interspecific hybrids. Results: The qualitative and quantitative analyses of pollen tube growth in situ were performed following intra- and interspecific pollinations. They revealed occurrence of pre-fertilization barriers associated with inhibition of pollen germination on the stigma and abnormal growth of pollen tubes. Unilateral incongruity related to differences in pistil length was also observed. The pollen quality was identified as a strong factor influencing the number of pollen tubes germinating in the stigma. In relation to post-fertilization barriers, endosperm degeneration was a probable barrier hampering production of interspecific hybrids. Moreover, our results demonstrate the relation of genetic distance estimated by AFLP marker analysis of hybridization partners with cross-compatibility of Kalanchoë species. At the same time, differences in ploidy did not influence the success of interspecific crosses. Conclusions: Our study presents the first comprehensive analysis of hybridization barriers occurring within Kalanchoë genus. Reproductive barriers were detected on both, pre- and post-fertilization levels. This new knowledge will contribute to further understanding of reproductive isolation of Kalanchoë species and facilitate breeding of new cultivars. For the first time, interspecific hybrids between K. nyikae as maternal plant and K. blossfeldiana as well as K. blossfeldiana and K. marnieriana were generated. [ABSTRACT FROM AUTHOR]

Out of the total accessions of cultivated barley, held at ICARDA, a subset core collection consisting of 153 accessions originating from different countries was established. Genetic diversity of the core collection was studied using AFLP markers. The accessions were grouped into different geographic sub-regions and the total genetic variation was estimated using Popgene software. Genetic distance matrix was computed and hierarchical unrooted tree was performed using Phylip software package. Our results demonstrate that the AFLP markers were highly informative and were useful in generating a meaningful classification of the cultivated barley that we determined as a subset of core collection.

Viola uliginosa Besser is a European violet having its main distribution range in the Baltic Sea region. Today it is considered endangered and threatened. Species of Violaceae from different genera and sections are known to produce cyclotides, cyclic polypeptides of much interest due to their medicinal properties and chemical structure. The present study introduced a rare species of violet ( V. uliginosa) to in vitro culture for biodiversity protection and as a model for cyclotide biosynthesis research in the Violaceae. Leaf and petiole fragments were cultured on MS medium solidified with agar and supplemented with different concentrations of plant growth regulators: TDZ, KIN and 2,4-D. Direct and indirect (via callus) organogenesis was induced on MS supplemented with TDZ (0.5 or 1 mg l) or with equal concentrations (2 mg l) of KIN and 2,4-D, followed by callus transfer on 1 mg l TDZ. Shoots were rooted on MS with 2 % sucrose and 0.5 mg l IBA and acclimatized. AFLP marker polymorphism was low but flow cytometry revealed that a large share of the obtained regenerants were tetraploid (2C = 4x = 2.7-2.8 pg), unlike the maternal diploid plants (2C = 2x = 1.4 pg). Eleven different cyclotides were distinguished in the aerial parts of maternal plants. Cyclotide production was significantly higher in tetraploid than in diploid plants regenerated in vitro. [ABSTRACT FROM AUTHOR]

Mountain plant species with wide elevational ranges are expected to be exposed to different selection pressures at low and high elevation. Estimating the extent of genetic population differentiation contributes to our understanding of selective forces shaping phenotypic variation of plants in response to changing climate conditions. Using a common garden experiment, we measured narrow-sense heritability ( h) and quantitative trait differentiation ( Q) in several growth-related, reproductive and phenological traits among low and high elevation populations of the semi-dry grassland species Ranunculus bulbosus from the Swiss Alps. Q values were compared to neutral genetic differentiation ( F) based on AFLP markers and indicated divergent selection in most traits among all populations as well as among low and high elevation populations separately. Furthermore, pairwise Q and F estimates were not correlated suggesting that neutral marker differentiation is not a valuable proxy for quantitative trait differentiation. Neutral molecular differentiation increased with geographical distance whereas quantitative genetic differentiation did not follow an isolation by distance pattern. Plant traits did mostly not differ among low and high populations and pairwise Q- F comparisons indicated no divergent selection between the two elevations. Differing levels of trait differentiation in low and high elevation populations, however, indicated that different selective forces acted on plants at contrasting elevations suggesting that selection regimes might alter under climate warming. [ABSTRACT FROM AUTHOR]