Genetic maps were compiled from the analysis of 160–180 doubled haploid lines derived from 3 crosses: Cranbrook Halberd, CD87 Katepwa, and Sunco Tasman. The parental wheat lines covered a wide range of the germplasm used in Australian wheat breeding. The linkage maps were constructed with RFLP, AFLP, microsatellite markers, known genes, and proteins. The numbers of markers placed on each map were 902 for Cranbrook Halberd, 505 for CD87 Katepwa, and 355 for Sunco Tasman. Most of the expected linkage groups could be determined, but 10–20% of markers could not be assigned to a specific linkage group. Homologous chromosomes could be aligned between the populations described here and linkage groups reported in the literature, based around the RFLP, protein, and microsatellite markers. For most chromosomes, colinearity of markers was found for the maps reported here and those recorded on published physical maps of wheat. AFLP markers proved to be effective in filling gaps in the maps. In addition, it was found that many AFLP markers defined specific genetic loci in wheat across all 3 populations. The quality of the maps and the density of markers differs for each population. Some chromosomes, particularly D genome chromosomes, are poorly covered. There was also evidence of segregation distortion in some regions, and the distribution of recombination events was uneven, with substantial numbers of doubled haploid lines in each population displaying one or more parental chromosomes. These features will affect the reliability of the maps in localising loci controlling some traits, particularly complex quantitative traits and traits of low heritability. The parents used to develop the mapping populations were selected based on their quality characteristics and the maps provide a basis for the analysis of the genetic control of components of processing quality. However, the parents also differ in resistance to several important diseases, in a range of physiological traits, and in tolerance to some abiotic stresses.
This paper describes and discusses strategies for screening microsatellites for use in plant genetic research and illustrates how a subset of useful microsatellites can be optimised for implementation on breeding and research using a range of techniques. Beginning with the initial screening of microsatellites for potential polymorphisms in a core set of potential parental lines, through to scaling up for mapping or breeding purposes, we present a time- and cost-effective approach to microsatellite analysis in wheat lines of interest. Each stage of this process benefits from a fresh examination of the techniques applied in order to increase the efficiency with which key markers can be identified and implemented. For the primary screening we use primers without modification to prime PCRs in the presence of f-dNTP (fluorescently labelled nucleotide) to provide the basis for high resolution screening for polymorphisms. As markers are defined for use in a breeding program, the focus changes to a smaller set of primer pairs that will be used to screen large numbers of DNA samples either from the analysis of progeny from a cross or the routine checking of cultivar identity in the industry. We then examine appropriate analysis platforms and refinement of PCR primers and conditions in order to identify procedures that can be implemented widely, not just in specialised well-equipped laboratories. In many cases we are able to use lower cost agarose analysis for identified polymorphisms. Where this is not feasable we examine primers for potential redesign to optimise their application either by altering the sequence of the primer itself, based on available sequence information, or by adding tails to the primers. The latter is shown to alter the ‘stutter’ pattern that is commonly observed with wheat microsatellites so that a single band is prominent and thus allows size polymorphisms to be more readily scored. The addition of a generic 5′ tail also provides a method of using a generic fluorescent primer that can be applied to multiple tagged markers in a costeffective fashion. The potential of alternative analytical systems and further refinement of primers to show plus/minus reactions with wheat lines in order to produce simple tests for use in breeding programs are also discussed.
Registered intermediaries are communication specialists appointed to facilitate the communication of vulnerable witnesses participating in the criminal justice system in England and Wales. Intermediaries assess the vulnerable individual's communication and provide recommendations to practitioners for how to obtain the individual's 'best evidence' during police interviews and in court. The scheme was implemented nationally in 2008, but has not been subject to rigorous research. The aim of the current article is to provide an account on adults' perceptions of the vulnerable individual when an intermediary assists their communication in court. In the present study one hundred participants viewed a mock cross examination of a child witness either with or without an intermediary present. Participants rated the child's behaviour and communication, and the quality of the cross examination, across a number of different variables. The age of the child was also manipulated with participants viewing a cross examination of a four or a thirteen year old child. The results showed the children's behaviour and the quality of the cross-examination were more highly rated when the intermediary was involved during cross-examination. The older child's crossexamination was rated as more developmentally appropriate, however no other age differences or interactions emerged. The findings have positive implications for jury perceptions of children's testimony when they are assisted by an intermediary in court, regardless of the age of the child witness. The success of the intermediary scheme in England and Wales may encourage the implementation of intermediaries internationally.
Microsatellite markers have been shown to be highly polymorphic and simple to use in hexaploid wheat. This study aimed to establish microsatellites as informative markers for Australian wheat improvement. By screening microsatellites developed as part of the Wheat Microsatellite Consortium and other available microsatellite sources, 257 informative microsatellites for Australian wheat varieties were identified and reported in the Australian National Wheat Molecular Marker Program microsatellite database (http://www.scu.edu.au/research/cpcg/). Of these, 151 microsatellites identifying 172 loci were scored on at least 1 of 4 double haploid mapping populations and were then integrated, where possible, into existing genetic maps. Polymorphism information content values were calculated for most microsatellites to establish a reference for their value for future investigations. The mapping of available microsatellites enhances the quality of the genetic maps and may provide useful genetic markers for traits of interest to the Australian wheat breeding programs.
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