Home About us Contact | |||
Amplified Fragment Length Polymorphism Markers (amplified + fragment_length_polymorphism_marker)
Selected AbstractsThe usefulness of amplified fragment length polymorphism markers for taxon discrimination across graduated fine evolutionary levels in Caribbean Anolis lizardsMOLECULAR ECOLOGY, Issue 3 2002R. Ogden Abstract Fine-level taxon discrimination is important in biodiversity assessment and ecogeographical research. Genomic markers are often required for studies on closely related taxa, however, most existing mitochondrial and nuclear markers require prior knowledge of the genome and are impractical for use in small conservation projects. This study describes the application of amplified fragment length polymorphism (AFLP) to discriminate at four progressively finer evolutionary levels of Caribbean Anolis lizards from the central Lesser Antilles. AFLP is shown to be a rapid and effective method for discriminating between species. Separation increases with primer pair number and choice of primer combination appears to be noncritical. Initial population-level results show markedly less discriminatory power. A screening technique for the identification of population informative markers combining principal component and principal coordinate analyses is presented and assessed. Subsequent results show selected conspecific AFLP data to be remarkably congruent with those of mitochondrial DNA, microsatellite and morphological markers. The use of AFLP as a low-cost nuclear marker in species-level taxon discrimination is supported, whereas population level application demands further consideration. [source] Development and characterization of SCAR markers associated with a dominant genic male sterility in rapeseedPLANT BREEDING, Issue 1 2008D. F. Hong Abstract Rs1046AB is a dominant genic male sterility (DGMS) line in rapeseed, in which the sterility has always been thought to be conditioned by the interaction of a male sterility gene (Ms) and its non-allelic restorer gene (Rf). This system provides not only a tool for assisting in recurrent selection but also a promising system for hybrid production. Based on previous studies, two amplified fragment length polymorphism markers linked with the Ms gene were converted into a dominant and a co-dominant sequence characterized amplified region (SCAR) marker, respectively. The putative linear order relationship of three dominant SCAR markers with the same genetic distance from the Rf gene, was also determined by an examination of whether the homologues of these markers are present or not in different lines carrying Rf. A bigger fragment generated by the closest marker linked to the Rf gene was observed in all lines carrying the recessive allele rf, suggesting that this marker is a co-dominant marker, which was further confirmed by nucleotide sequence comparison of these fragments. SCAR markers specific for Ms and Rf will be especially valuable in marker-assisted DGMS three-line breeding. [source] Clustering of amplified fragment length polymorphism markers in a linkage map of ryePLANT BREEDING, Issue 2 2002B. Saal Abstract Amplified fragment length polymorphisms (AFLPs) are now widely used in DNA fingerprinting and genetic diversity studies, the construction of dense genetic maps and in fine mapping of agronomically important traits. The AFLP markers have been chosen as a source to extend and saturate a linkage map of rye, which has previously been generated by means of restriction fragment length polymorphism, random amplified polymorphic DNA, simple sequence repeat and isozyme markers. Gaps between linkage groups, which were known to be part of chromosome 2R, have been closed, thus allowing the determination of their correct order. Eighteen EcoRI- MseI primer combinations were screened for polymorphism and yielded 148 polymorphic bands out of a total of 1180. The level of polymorphism among the different primer combinations varied from 5.7% to 33.3%. Eight primer combinations, which revealed most polymorphisms, were further analysed in all individuals of the F2 mapping population. Seventy-one out of 80 polymorphic loci could be integrated into the linkage map, thereby increasing the total number of markers to 182. However, 46% of the mapped AFLP markers constituted four major clusters located on chromosomes 2R, 5R and 7R, predominantly in proximity to the centromere. The integration of AFLP markers caused an increase of 215 cM, which resulted in a total map length of almost 1100 cM. [source] Genetic and phenotypic differences between thistle populations in response to habitat and weed management practicesBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2010RICCARDO BOMMARCO Rapid evolutionary change is increasingly being recognized as commonplace, but the evolutionary consequences for species and ecosystems under human-induced selection regimes have not been explored in detail, although many species occur in such environments. In a common garden experiment and with amplified fragment length polymorphism markers, we examined whether genetic differentiation has taken place between spatially intermixed populations of creeping thistles Cirsium arvense (Asteraceae) collected from a natural habitat (maritime shores), a semi-natural habitat (road verges) and arable fields under two management regimes: conventional and organic farming. Populations of C. arvense have altered genetically and locally adapted their growth patterns with changed land use. Although plants from different habitats showed similar total biomass production, shoot and root production was higher for maritime populations, suggesting selection for increased competitive ability. Competitive ability then declined in the order semi-natural, conventional farms and organic farms. Thistles in arable fields may be more selected for tolerance against disturbances from herbicides and mechanical weed control. In addition, early shoot sprouting and genetic analysis showed differentiation between plants originating from conventional farms and farms that were converted to organic 9,30 years ago, suggesting some adaptation to altered crop cultivation practices. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99, 797,807. [source] |