Ortet selection remains an integral component of cacao breeding programme to develop improved clones and expand the gene pool of available germplasm. This study assessed the population structure of 168 cacao clones developed recently from selected ortets in on-station and on-farm progeny trials in Ghana using 45 SNP markers. Selection of ortets was primarily based on high bean yield, high yield efficiency, adaptability to marginal growing conditions, and low incidence of black pod and cocoa swollen shoot virus diseases. Additionally, 58 SNPs were employed to verify the parentage of 752 bi-clonal seedlings supplied to farmers for commercial plantations. Pairwise multilocus matching based on 45 SNPs showed that the 168 clones were all distinct. Overall, the clones had moderate genetic diversity (He = 0.349 ± 0.022) and shared ancestry with Marañón, Guiana, Contamana, Iquitos, Amelonado, Trinitario, Nanay and Purús based on Bayesian clustering, principal coordinates, and parentage analyses. Parentage analysis of bi-clonal seedlings assigned parent-offspring trios (>80% confidence level) to 65.2% of the farmers' varieties based on breeder's active clone collection. The results of the parentage analysis suggested the existence of mislabelled clones in the seed gardens, necessitating the need for correct clone identification or rogueing. Taken together, this study presents a new group of cacao genetic resources with potential to broaden the gene pool of cacao in cacao improvement programmes. Further, the study conveys evidence of the need for countries with established seed garden systems to constantly monitor the genetic purity of seedlings produced from the seed gardens.

Developed in Britain and the United States in the 1980s, genetic profiling has since become a global technology. Today, it is widely regarded as the evidentiary “gold standard” in individual and forensic identification. However, its origins as a technology of post-empire at Britain’s externalized borders in South Asia have remained unexamined. This article will argue that the first state-sanctioned use of “DNA fingerprints,” a pilot program exploring its value in disputed cases of family reunification migration from Bangladesh and Pakistan to Britain’s postcolonial cities, repays closer examination. National and transnational responses to the advent of genetic profiling as an identification technology demonstrate the interplay between imperial and postcolonial models and networks of power and truth production. At the same time, this experiment prefigured and conditioned the wider reception of DNA profiling in matters of kinship. Far from being a footnote, the use of genetic profiling by migrants determined to exercise their legal rights in the face of a hostile state also worked to naturalize genetic ties as the markers of “true” familial relationships.

This study assessed the genetic diversity of African yam bean (AYB) accessions using morphological and molecular markers. The accessions were grown, and morphological data collected were subjected to analysis of variance and multivariate analyses. Genomic DNA extracted from the accessions were amplified with inter simple sequence repeat (ISSR) markers. The diversity analysis was conducted using MEGA4 software. The accessions varied significantly (P < 0.05) in growth, flowering and seed-related parameters. Flowering commenced early in most accessions. Weight of 100-seed range from 15.01 to 21.15 g with the mean value of 18.30 g. Significant correlations existed between stem height, the number of leaves and leaf dimensions. Also, days to flowering correlated with pod formation; likewise, seed dimension had a positive association with seed weight. The principal biplot revealed that two components accounted for 41.77% of the observed variation. Analysis of the electropherogram showed 95 loci comprising 1351 alleles were detected by the ISSR markers with 65.26% polymorphism and combined polymorphic information content of 0.85. The principal coordinate analysis placed accessions together on a plane based on their spatial relationship. The dendrogram showed accession pairs (TSs-77, TSs-95) and (TSs-111, TSs-84) are closely related. The phylogram identified three kinships with a total length of 454. Accession TSs-115 is likely the progenitor while TSs-82 and TSs-86 are the most recent. The study concluded that a combination of morphological and ISSR markers is effective for the diversity study of AYB and the existing, genetic diversity in the accessions could be harnessed for its improvement, conservation and utilization.

Andean blackberry (Rubus glaucus Benth.) is an emerging fruit crop with significant commercial potential. Despite its growing popularity, basic research about its genetic resources and breeding remains insufficient. The aim of this study was to assess the genetic diversity of Andean blackberry cultivars and related berries species from the main production areas in Ecuador. We analysed a total of 106 samples and performed DNA screening with different molecular markers: random-amplified polymorphic DNAs (RAPDs), inter-simple sequence repeats (ISSRs) and a set of representative samples with amplified fragment length polymorphisms (AFLPs). The tested RAPD primers did not reveal any differentiation among accessions identified as R. glaucus, however one ISSR primer was useful to find polymorphisms allowing the selection of 29 accessions for the analysis with AFLP markers. AFLP-M13 technology was used for screen genetic variations among these accessions and eight wild Rubus accessions. We scored 203 bands using five primer combinations; out of these 152 were informative in R. glaucus. AFLP markers clearly distinguish R. glaucus from the screened wild Rubus species, also an unexpected genetic structure was revealed among R. glaucus cultivars. This genetic differentiation and detection of admixed genotypes suggest a possible introgression of wild Rubus species in R. glaucus. Our findings are relevant for blackberry genetic breeding and use of these genetic resources.

Genetic variation was assessed in a range of populations of wild mustard (Sinapis arvensis L.) using random amplified polymorphic DNA (RAPD) analysis. Sixty markers were used to assess the extent of genetic variation in wild mustard populations sampled throughout 12 different locations in the United Kingdom, including herbicide treated and untreated sites. In addition, selected sites were sampled over two consecutive seasons. Individual plant analysis was required, since a high degree of intra-population genetic variation was observed. The apparent extent of genetic variation in a population at one site increased when the results from two consecutive seasons were assessed. The range of genetic variation was as high in the herbicide-treated populations as in those which were untreated. Genetic diversity was maintained in populations of wild mustard where rotational cropping and herbicide use was practiced. These results confirm the utility of RAPD for the determination of genetic variation in outcrossing species where no prior genotypic knowledge is available.

Red rice is a major weed in rice production in the southern United States. Red rice and rice intercross because they are the same species. Our objectives were to determine the genetic diversity represented by accessions of red rice and to identify DNA markers that might be useful in identifying hybrids between red and cultivated rice. Red rice accessions were collected from Arkansas and other rice-producing states. Seventy-nine red rice accessions, 10 known or putative hybrid derivatives of red rice and cultivated rice (RC hybrids), and seven rice cultivars were analyzed using microsatellite DNA markers developed for cultivated rice. Microsatellite markers differentiated awned and awnless red rice accessions, six of the seven rice cultivars, and all 10 RC hybrids tested. Thus, these markers were useful in identifying red rice types and RC hybrids.

Two DNA molecular marker techniques were used to evaluate genetic diversity in 58 accessions of jointed goatgrass and 6 accessions of the related wild species barb goatgrass. Random amplified polymorphic DNA (RAPD) assays were performed on 8 U.S. and 50 Eurasian jointed goatgrass accessions using 30 random decamer primers. The frequency of scorable polymorphic bands within jointed goatgrass was 6 out of 90 (6.7%). Cluster analysis of RAPD data showed small genetic distances (values of 0.005 or less) among jointed goatgrass accessions. To validate the effectiveness of RAPD techniques to detect genetic diversity in tetraploid Aegilops species, six accessions of barb goatgrass were assayed using a subset of 20 decamer primers (from the original 30). RAPD data for barb goatgrass were pooled with jointed goatgrass data from the same primers. A total of 63 scorable bands were generated, of which 27 (43%) were polymorphic between two or more accessions. RAPD analysis readily distinguished between the two species and detected much greater levels of genetic diversity within barb goatgrass than between the jointed goatgrass accessions. Amplified fragment length polymorphism (AFLP) assays were performed on a subset of the 58 jointed goatgrass accessions, 3 U.S. and 13 Eurasian. These accessions were selected to represent a range in geographic diversity within our collection. Ten primer combinations generated 560 scorable bands of which 28 (5%) were polymorphic. Cluster analysis of AFLP data showed a slightly smaller range in genetic distance (0.0002 to 0.0022) among accessions compared with RAPD results; however, AFLPs distinguished among all but 2 of the 16 accessions surveyed. Although AFLP produced more scorable bands than RAPD did, both methods revealed limited genetic diversity in jointed goatgrass.

In India, the registration and protection of new and notified/extant plant varieties are based on the criteria of distinctness, uniformity and stability (DUS) of morphological characteristics. However, these morphological traits have not been helpful in resolving closely related genotypes. The molecular markers can very well support the DUS testing in such cases. Therefore, in the present study, 20 accessions of bottle gourd were fingerprinted using 20 simple sequence repeat (SSR) primers. Of these, ten primers exhibited polymorphic profiles, while nine exhibited monomorphic patterns and one revealed a null allele. The number of alleles ranged from 2 to 4 with an average of 2.6 alleles per locus. Unique DNA profiles of all the accessions could be created using a set of five polymorphic primers. Therefore, SSR markers used in the present study could precisely distinguish all the 20 accessions from each other, and these SSR markers can be further used to differentiate the future genotypes from the existing ones. The dendrogram depicting the genetic relationships as revealed by NTSYS-pc 2.02 and the tree diagram generated using the DARwin 5.0 program classified the accessions into two main clusters. There is no strong association between the clustering pattern and geographical origin of these accessions. This SSR marker-based diversity would facilitate the implementation of marker-assisted breeding schemes for efficient introduction of the desired traits into bottle gourd.

Introduction. Consumption of Physalis fruits is quite recent and the products are poorly known among consumers. This plant has been known for a long time as an ornamental in Europe, for at least 200 years. Traceability is increasingly becoming important across the agri-food industry; however, at the present time, the traceability of this fruit is only documentary. In case of doubt or fraud, no standardized analysis can determine the geographical origin of the fruits. Materials and methods. In order to discover the relationship between the fungal communities of the fruit and their geographical origins, 28S rDNA-PCR-DGGE was used to analyze the variation in fungal communities in three species of Physalis fruit (Physalis ixocarpa Brot., Physalis pruinosa L. and Physalis peruviana L.) from Egypt, Uganda and Colombia. Results. Denaturing Gradient Gel Electrophoresis (DGGE) fingerprints of 28S ribosomal DNA (28S rDNA) analyzed by multivariate analysis could distinguish different fruit origins by their fungal communities. Conclusion. We propose the PCR-DGGE method as a new traceability tool which provides fruit in general, and Physalis in particular, with a unique barcode for each country by using 28S rDNA fingerprinting of fungi.

Prunus avium cultivars widely used in northern Greece were investigated in terms of inter- and intra-cultivar genetic variation and DNA fingerprinting. Based on 11 simple sequence repeats loci, the average number of alleles per locus (Na = 2.82), probability of identity (PID = 0.327), polymorphic information content (0.451) and expected heterozygosity (He = 0.494) were within the range reported in similar studies. The most informative markers were BPPCT039 and EMPa018. The cultivars were clearly separated in both an unweighted pair group method with arithmetic mean dendrogram and a multivariate space ordination. Any two cultivars differed on the average at 6.30 loci. The null hypothesis of zero intra-cultivar variability was tested and could not be rejected. Two cultivars (Tragana Edessis and Tragana Sarakinon) were genetically similar, but not identical. This study, the first of its kind for sweet cherry in Greece, presents a useful molecular tool for resolving issues of intra-cultivar variability and synonimity and provides a warranty of genetic identity in the handling and management of local traditional germplasm.

In India, Protection of Plant Varieties and Farmer's Rights Act (PPV&FRA, 2001) requires the registration and protection of new and notified/extant plant varieties based on the criteria of distinctness, uniformity and stability (DUS) of morphological characteristics. However, these morphological traits have not been able to resolve closely related genotypes. The molecular markers can very well support the DUS testing in such cases. In the present study, therefore, 14 varieties of rice cultivated in Punjab state of India were fingerprinted using 75 simple sequence repeat (SSR) primers. Out of these, 58 primers produced polymorphic profiles, while 13 were monomorphic, 2 revealed null allele and the remaining 2 amplified only from super basmati. In a screen of 7 cultivars, 16 SSR loci produced 17 rare/unique alleles, which provided an opportunity for their unambiguous identification. Cluster analysis based on SSR data clearly distinguished the cultivars into two dist inct groups: comprising non-basmati (group I) and basmati (group II). The cluster pattern was consistent with the pedigree and breeding history of the cultivars.

Two synthetic DNA probes composed of tandemly repeated ‘core’ sequences (GACA and GATA) were used to examine genetic diversity at multiple variable-number-tandem-repeat (VNTR) loci within and among four spatially isolated Philippine populations of Rubus moluccanus L. (Rosaceae), an uncultivated bramble widely distributed throughout southeast Asia – Malesia. Central goals were to determine whether apomictic propagation was detectable in R. moluccanus and to examine whether populations isolated on separate islands, or on mountain tops on a single island, were genetically differentiated. Sampling 22 individuals per population, the findings include: (1) no two individuals shared identical VNTR band profiles and thus apomictic propagation was not detected; (2) the mean number of bands scored per individual was 24.3 (SD = 3.91) and the proportion of polymorphic loci within populations ranged from 0.69 to 1.00 (mean = 0.86 ± SD = 0.085); (3) the average proportion of bands shared between individuals within populations ranged from 0.39 to 0.67 (0.50 ± 0.067), while average interpopulation similarity ranged from 0.21 to 0.50 (0.32 ± 0.092); and (4) estimated heterozygosity within populations ranged from 0.42 to 0.79 (0.62 ± 0.083), while interpopulation heterozygosity ran from 0.62 to 0.81 (0.74 ± 0.062). Permutation tests were used to estimate the statistical significance of differences in similarity between populations. A Luzon population isolated by 1200 km was always significantly different in similarity tests when compared with each of the other three populations, all located on Mindanao (and separated by at least 100 km but less than 250 km). Of the latter three, only one population differed significantly from the other two in the degree of VNTR markers shared, possibly reflecting biogeographic partitioning suggested for the island. Across all populations, average estimated Fst was 0.154, although mean inter-island Fst (0.224) was significantly higher than mean intra-island Fst (0.085). These results suggest that, while intra-island gene flow is relatively high, significant differentiation of tropical species may occur even over short distances on individual islands. Preservation of only a limited number of populations may result in a significant loss of genetic diversity in such species.

Experiments were performed to determine if RAPD profiles developed using total DNA isolated from soybean seed could be affected by the physiological state or the quality of the seed. RAPD profiles were developed using template DNA isolated from a single seed lot of soybean (Glycine max L. cv. Kirby). High quality seeds were used to produce four populations varying in either quality or physiological state: untreated control seed ambient temperature and humidity storage for 12 months, accelerated aging at 41°C and 100% relative humidity for 48 h, and controlled hydration (seed priming). One hundred and eighty-eight primers were used to create separate RAPD profiles from total DNA isolated from each set of seed and from soybean leaf tissue. Sixteen polymorphisms from 14 primers were identified as a result of seed treatments. Six primers showed nine polymorphisms in RAPD profiles of ambient-stored seed DNA, while four and two primers produced polymorphisms in reactions using accelerated aged or primed-seed template DNA, respectively. Two primers showed a polymorphic fragment in vegetative DNA not observed in any of the seed DNA samples. Ten of the observed polymorphisms were due to the appearance of a DNA fragment in response to a specific seed treatment while six were the result of the treatment-induced loss of a DNA fragment. The six polymorphisms resulting from the loss of a major fragment were all due to ambient-temperature seed storage. Results were reproducibly obtained from multiple DNA isolations using three separate DNA isolation procedures involving either multiple seed or a single seed as the template source. Therefore, genetically identical seed can consistently display RAPD polymorphisms as a response to the environmental exposure.

Nineteen kenaf genotypes from Cuba, Taiwan, the USA, El Salvador, Guatemala, Russia, Spain and Indonesia, and three wild types collected in South Africa were analysed for genetic diversity using AFLP analysis. All could be uniquely distinguished from one another, but only a low level of genetic diversity was present. The most distinct accession, Guatemala 4, was 85% similar to all other accessions. The accessions clustered more or less according to known pedigree and/or origin. Two of the three wild types (Hibiscus cannabinus c and H. cannabinus a) clustered separately from the commercial and Russian accessions. One of the wild types, H. cannabinus b clustered with some of the commercial accessions. Commercial accessions in the first subgroup all originated from central and North America, and surrounding islands (Cuba and El Salvador). The Russian accessions are all grouped together. The second subgroup was the only group that contained accessions from different geographical origins.

Introduction. Consumption of citrus fruits and their juice has strongly grown in the last few decades. However, at the present time, the traceability of these fruits is only documentary. In case of doubt or fraud, no standardized analysis makes it possible to discriminate or determine the geographical origin of culture of the fruit. Materials and methods. A method of bacterial ecology, PCR-DGGE, was used to characterize the bacterial flora of clementines imported into France from Spain and Morocco in order to show that there is a relation between the bacterial communities of the fruits and their geographical origins. The principle rests on the determination of specific biological markers for a given region. Protocols of microbial extraction and DNA amplification were optimized. Results. DGGE profiles analyzed by multivariate analysis permitted us to distinguish microbial communities from different origins. Conclusion. We propose the PCR-DGGE method as a new tool for traceability that provides citrus products with a unique bar code and makes it possible to trace back the citrus fruit to their original location.

Amplified fragment length polymorphism (AFLP) markers were employed to assess intraspecific variability in water yam (Dioscorea alata L.). Fifty-three accessions of diverse geographic origins in West and Central Africa (Benin, Côte d'Ivoire, Ghana, Nigeria and Chad) and Puerto Rico were analysed using three AFLP primer combinations. Of the 342 amplification products generated, a mean of 53.4% were polymorphic. Genetic similarity coefficients ranged from 0.29 to 0.95. The accessions could be clustered into three major genetic groups with one outlier. Each group was a mixture of accessions of different geographical origin indicating that geography has not played a major role in the differentiation of the species. A few accessions clustered very tightly suggesting that there may be duplicate accessions in the collection. The wide genetic variation observed constitutes a good basis for genetic improvement of yam.

The paper outlines the impact of molecular biology on the identification and detection of fungi and fungus-like micro-organisms. We have tried to use as little jargon as possible but avoiding it completely is very difficult. The article is centred around the ‘pseudofungus’ Phytophthora and its closest relatives, because that is the micro-organism with which we have had most experience. Nevertheless, most of the approaches and techniques mentioned are applicable to any fungus or fungus-like organism and, in that broader sense, the article should be of interest to those with no special interest in or knowledge of Phytophthora.

The potential for the non-coding intergenic rDNA spacer (IGS) to DNA fingerprint Giardia duodenalis isolates was investigated. Conserved PCR primers, specific for the flanking large and small rDNA genes, were used to amplify the IGS from 52 in vitro-cultured Giardia isolates. Four distinct IGS–PCR size groups (1·35–1–6 kb) were observed, which correlated closely with the major genetic assemblages established previously for the same isolates using isoenzyme analysis. IGS–PCR size groups A (1·42 kb), C (1·4 kb) and D (1·35 kb) corresponded to isoenzyme assemblage A, and IGS–PCR group B (1·6 kb) to isoenzyme assemblage B. Amplified products from IGS–PCR size groups A and B, which contained 50/52 isolates, were subsequently digested with 8 different restriction enzymes and their profiles compared. Analysis separated isolates within each IGS–PCR size group into 2 distinct clusters which correlated almost exactly with the same genetic groups established previously using isoenzyme electrophoresis. Within each cluster, both methods exhibited a similar capacity to distinguish between Giardia genotypes although they established different genetic relationships between individual isolates. Much of the variability associated with the IGS was attributed to isolates harbouring multiple IGS- sequence types. Restriction analysis of IGS–PCR products amplified from cloned and parent lines of a human isolate BAH 39, which contains multiple IGS variants, showed that trophozoite populations are homogeneous with respect to the types of IGS-variants they maintain. Furthermore, in vitro culture of the cloned isolate BAH39c9 over a 6-year period also failed to reveal variation in IGS–PCR digestion profiles. These results suggest that IGS–PCR RFLP profiles are inherently stable. IGS–PCR analysis was successfully applied to 11 Giardia cyst samples highlighting the potential for this approach to genotype Giardia isolates without the need for in vitro culture.

The total DNA of ten isolates of different chlorophycean algal genera was extracted according to a protocol for the extraction of fungal DNA. Algal DNA was digested with up to ten different restriction endonucleases. In Southern hybridizations, DNA was probed with a digoxigenin-labelled 440 base pair (bp) fragment of bacteriophage M13 containing a repetitive sequence with a 15 bp core repeat. Stringency conditions for the detection of banding patterns in algae of different genera are described. The stability of DNA fingerprints of subcultures of the same isolate was investigated. DNA fingerprints of isolates of the genera Chlorella, Klebsormidium and Stichococcus were compared. The results show that the M13 minisatellite probe can be used to detect DNA fingerprints in chlorophyte algae of different genera and to differentiate isolates of the same species.