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Present study aims to testify usefulness of particular wheat SSR markers for the detection of genetic diversity degree in the set of 59 triticale cultivars and new lines coming from different European countries and USA. For this purpose, a set of fifteen SSR markers were used. One SSR marker (Xwmc429) gave a uniform spectrum. The set of fourteen polymorphic markers provided 94 alleles with an average frequency of 6.71 alleles per locus. The number of alleles ranged between 2 (Xbarc 195) and 10 (Xbarc 137). Resulting from the number and frequency of alleles, diversity index (DI), polymorphic information content (PIC) and probabilities of identity (PI) were calculated. An average value of PIC for 14 markers was 0.640, the highest value was calculated for wheat SSR marker Xgwm 46 (0.809). Based on UPGMA algorithm, a dendrogram was constructed. It was able to separate 57 of 59 cultivars (96,6%) from each other. American new-line NE- 422T significantly separated from all cultivars and new lines. Only two french cultivars Bienvenu and Wilfried had not been separated from each other. A tested set of SSR markers allowed to better understand genetic relationships among European cultivars and American new lines. In general, a dendrogram along with results of calculated genetic indicators such as PIC, PI and DI point out at SSRs markers as high informative and usefull tool in genetic diversity research between close-related species. [ABSTRACT FROM AUTHOR]

Stem rust has become a renewed threat to global wheat production after the emergence and spread of race TTKSK (also known as Ug99) and related races from Africa. To elucidate U.S. winter wheat resistance genes to stem rust, association mapping was conducted using a panel of 137 lines from cooperative U.S. winter wheat nurseries from 2008 and simple sequence repeat (SSR) and sequence tagged site (STS) markers across the wheat genome. Seedling infection types were evaluated in a greenhouse experiment using six U.S. stem rust races (QFCSC, QTHJC, RCRSC, RKQQC, TPMKC and TTTTF) and TTKSK, and adult plant responses to bulked U.S. races were evaluated in a field experiment. A linearization algorithm was used to convert the qualitative Stakman scale seedling infection types for quantitative analysis. Association mapping successfully detected six known stem rust seedling resistance genes in U.S. winter wheat lines with frequencies: Sr6 (12%), Sr24 (9%), Sr31 (15%), Sr36 (9%), Sr38 (19%), and Sr1RSAmigo (8%). Adult plant resistance gene Sr2 was present in 4% of lines. SrTmp was postulated to be present in several hard winter wheat lines, but the frequency could not be accurately determined. Sr38 was the most prevalent Sr gene in both hard and soft winter wheat and was the most effective Sr gene in the adult plant field test. Resistance to TTKSK was associated with nine markers on chromosome 2B that were in linkage disequilibrium and all of the resistance was attributed to the Triticum timopheevii chromosome segment carrying Sr36. Potential novel rust resistance alleles were associated with markers Xwmc326-203 on 3BL, Xgwm160-195 and Xwmc313-225 on 4AL near Sr7, Xgwm495-182 on 4BL, Xwmc622-147 and Xgwm624-146 on 4DL, and Xgwm334-123 on 6AS near Sr8. Xwmc326-203 was associated with adult plant resistance to bulked U.S. races and Xgwm495-182 was associated with seedling resistance to TTKSK. [ABSTRACT FROM AUTHOR]

Summary: Background: We aimed to accurately estimate the frequency of a hexanucleotide repeat expansion in C9orf72 that has been associated with a large proportion of cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Methods: We screened 4448 patients diagnosed with ALS (El Escorial criteria) and 1425 patients with FTD (Lund-Manchester criteria) from 17 regions worldwide for the GGGGCC hexanucleotide expansion using a repeat-primed PCR assay. We assessed familial disease status on the basis of self-reported family history of similar neurodegenerative diseases at the time of sample collection. We compared haplotype data for 262 patients carrying the expansion with the known Finnish founder risk haplotype across the chromosomal locus. We calculated age-related penetrance using the Kaplan-Meier method with data for 603 individuals with the expansion. Findings: In patients with sporadic ALS, we identified the repeat expansion in 236 (7·0%) of 3377 white individuals from the USA, Europe, and Australia, two (4·1%) of 49 black individuals from the USA, and six (8·3%) of 72 Hispanic individuals from the USA. The mutation was present in 217 (39·3%) of 552 white individuals with familial ALS from Europe and the USA. 59 (6·0%) of 981 white Europeans with sporadic FTD had the mutation, as did 99 (24·8%) of 400 white Europeans with familial FTD. Data for other ethnic groups were sparse, but we identified one Asian patient with familial ALS (from 20 assessed) and two with familial FTD (from three assessed) who carried the mutation. The mutation was not carried by the three Native Americans or 360 patients from Asia or the Pacific Islands with sporadic ALS who were tested, or by 41 Asian patients with sporadic FTD. All patients with the repeat expansion had (partly or fully) the founder haplotype, suggesting a one-off expansion occurring about 1500 years ago. The pathogenic expansion was non-penetrant in individuals younger than 35 years, 50% penetrant by 58 years, and almost fully penetrant by 80 years. Interpretation: A common Mendelian genetic lesion in C9orf72 is implicated in many cases of sporadic and familial ALS and FTD. Testing for this pathogenic expansion should be considered in the management and genetic counselling of patients with these fatal neurodegenerative diseases. Funding: Full funding sources listed at end of paper (see Acknowledgments). [ABSTRACT FROM AUTHOR]

Sunflower rust. caused by Puccinia helianthi, is a prevalent disease in many countries throughout the world. The U.S. Department of Agriculture (USDA)-Agricultural Research Service, Sunflower Research Unit has released rust resistant breeding materials for several decades. However, constantly coevolving rust populations have formed new virulent races to which current hybrids have little resistance. The objectives of this study were to identify resistance to race 336, the predominant race in North America, and to race 777, the most virulent race currently known. and to validate molecular markers known to be linked to rust resistance genes in the sunflower gene pool. A total of 104 entries, including 66 released USDA inbred lines, 14 USDA interspecific germplasm lines, and 24 foreign germplasms, all developed specifically for rust resistance, were tested for their reaction to races 336 and 777. Only 13 of the 104 entries tested were resistant to both races, whereas another six were resistant only to race 336. The interspecific germplasm line, Rf ANN-1742, was resistant to both races and was identified as a new rust resistance source. A selection of 24 lines including 19 lines resistant to races 777 and/or 336 was screened with DNA markers linked to rust resistance genes Rj, R2, R4u, and R5. The results indicated that the existing resistant lines are diverse in rust resistance genes. Durable genetic resistance through gene pyramiding will be effective for the control of rust. [ABSTRACT FROM AUTHOR]

Characterization and genotype identification are essential for rational conservation, management and genetic diversity evaluation. In this work, simple sequence repeat (SSR) markers were used to identify 57 accessions of sweet potato kept at the 'in vitro' Gene Bank of INTA, Argentina. This collection includes primitive materials from primary zones of dispersion, commercial varieties, breeding clones and foreign materials from different parts of the world (Africa, Asia and USA). Average similarity between the materials evaluated was 0.367. Grouping analysis revealed six clusters and a strong association with skin colour of storage roots. The set of selected SSR markers allowed us to verify identity, detect duplicates and estimate the genetic similarity of the materials analysed. This characterization complements morphological data and provides tools to estimate the variation of diversity between local and foreign germplasm groups [ABSTRACT FROM AUTHOR]

Abstract: Ongoing work at the U.S. National Institute of Standards and Technology has focused on the characterization of 26 autosomal STR loci for human identity testing. These 26 loci are in addition to the existing 13 U.S. core loci and those found in PowerPlex16 and Identifiler commercial STR typing kits. The amplification of the 26 loci has been optimized for degraded extracts in unique miniplex panels and also for reference samples as a single reaction 26plex assay. A study has been performed comparing genotypes obtained with the 26plex primers to those with miniplex panels for allele drop out and concordance. The forensic utility of the 26plex assay was evaluated for situations where additional loci are beneficial. The utility of this large multiplex was also tested in a case involving DNA extracted from degraded bone samples. The 26plex can serve as a low-cost assay (compared to commercially available kits) useful for both sorting comingled remains and providing additional markers for increased statistical support for samples that require “non-trio” family references for human identification. [Copyright &y& Elsevier]

Abstract: U.S. population sample sets have been tested at the SE33 locus with PowerPlex ESX 17 and ESI 17 as well as AmpFlSTR NGM SElect, Investigator ESSplex SE, and the widely used “Polymeropoulos” primers to explore any concordance issues between kits possessing primers in different positions. A G→A mutation 68bp downstream of the repeat region has been detected in several samples that can cause a mobility shift in PowerPlex ESI 17 and ESSplex SE relative to PowerPlex ESX 17 and NGM SElect SE33 alleles. In addition, a C→T mutation 60bp downstream of the repeat region created the same mobility shift and allele dropout with the ESX 17 kit. [Copyright &y& Elsevier]

Abstract: A total of 853 samples from the four major U.S. population groups (African American, Asian, Caucasian, and Hispanic) were typed using the Qiagen® Investigator Argus X-12 kit. Allele frequency distributions are reported here for each of the 12 X-STR markers (DXS10103, DXS8378, DXS7132, DXS10134, DXS10074, DXS10101, DXS10135, DXS7423, DXS10146, DXS10079, DXS10148, and HPRTB). [Copyright &y& Elsevier]

Abstract: Multiple concordance studies have been performed at NIST with a standard sample set (≈1450 U.S. population samples) using various STR multiplex kits from Applied Biosystems, Promega Corporation, and Qiagen, including many of the new generation European kits. Out of 948,301 allele comparisons, differences were observed 1109 times resulting in a concordance rate of 99.88%. These differences were reported to the collaborating commercial vendors, which in many cases lead to revised kits and a reduction in null alleles through the addition of degenerate primers or primer redesign. [Copyright &y& Elsevier]