26
|
Powell W, Adams LB, Cole-Lewis Y, Agyemang A, Upton RD. Masculinity and Race-Related Factors as Barriers to Health Help-Seeking Among African American Men. Behav Med 2016; 42:150-63. [PMID: 27337619 PMCID: PMC4979354 DOI: 10.1080/08964289.2016.1165174] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Men's tendency to delay health help-seeking is largely attributed to masculinity, but findings scarcely focus on African American men who face additional race-related, help-seeking barriers. Building principally on reactance theory, we test a hypothesized model situating racial discrimination, masculinity norms salience (MNS), everyday racism (ERD), racial identity, sense of control (SOC), and depressive symptomatology as key barriers to African American men's health help-seeking. A total of 458 African American men were recruited primarily from US barbershops in the Western and Southern regions. The primary outcome was Barriers to Help-Seeking Scale (BHSS) scores. The hypothesized model was investigated with confirmatory factor and path analysis with tests for measurement invariance. Our model fit was excellent [Formula: see text] CFI = 0.99; TLI = 1.00; RMSEA = 0.00, and 90% CI [0.00, 0.07] and operated equivalently across different age, income, and education strata. Frequent ERD and higher MNS contributed to higher BHHS scores. The relationship between ERD exposure and BHHS scores was partially mediated by diminished SOC and greater depressive symptomatology. Interventions aimed at addressing African American men's health help-seeking should not only address masculinity norms but also threats to sense of control, and negative psychological sequelae induced by everyday racism.
Collapse
|
27
|
Blackmore T, Thorogood D, Skøt L, McMahon R, Powell W, Hegarty M. Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne. Sci Rep 2016; 6:22603. [PMID: 26935901 PMCID: PMC4776279 DOI: 10.1038/srep22603] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/05/2016] [Indexed: 11/09/2022] Open
Abstract
Perennial ryegrass (Lolium perenne) is the most widely grown temperate grass species globally. Intensive plant breeding in ryegrass compared to many other crops species is a relatively recent exercise (last 100 years) and provides an interesting experimental system to trace the extent, impact and trajectory of undomesticated ecotypic variation represented in modern ryegrass cultivars. To explore germplasm dynamics in Lolium perenne, 2199 SNPs were genotyped in 716 ecotypes sampled from 90 European locations together with 249 cultivars representing 33 forage/amenity accessions. In addition three pseudo-cross mapping populations (450 individual recombinants) were genotyped to create a consensus genetic linkage map. Multivariate analyses revealed strong differentiation between cultivars with a small proportion of the ecotypic variation captured in improved cultivars. Ryegrass cultivars generated as part of a recurrent selection programme (RSP) are strongly associated with a small number of geographically localised Italian ecotypes which were among the founders of the RSP. Changes in haplotype frequency revealed signatures of selection in genes putatively involved in water-soluble carbohydrate (WSC) accumulation (a trait selected in the RSP). Retrospective analysis of germplasm in breeding programmes (germplasm dynamics) provides an experimental framework for the identification of candidate genes for novel traits such as WSC accumulation in ryegrass.
Collapse
|
28
|
Mulvaney D, Greene W, Powell W, Bates E, Smith B. 023 Beef ambassador programming: A case for coming alongside the beef community to develop agvocacy and leadership skills in youth. J Anim Sci 2016. [DOI: 10.2527/ssasas2015-023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
29
|
Sasano M, Yasuda J, Zegers RGT, Baba H, Chao W, Dozono M, Fukuda N, Inabe N, Isobe T, Jhang G, Kamaeda D, Kubo T, Kurata-Nishimura M, Milman E, Motobayashi T, Otsu H, Panin V, Powell W, Sakai H, Sako M, Sato H, Shimizu Y, Stuhl L, Suzuki H, Tangwancharoen S, Takeda H, Uesaka T, Yoneda K, Zenihiro J, Kobayashi T, Sumikama T, Tako T, Nakamura T, Kondo Y, Togano Y, Shikata M, Tsubota J, Yako K, Shimoura K, Ota S, Kawase S, Kubota Y, Takaki M, Michimasa S, Kisamori K, Lee C, Tokieda H, Kobayashi M, Koyama S, Kobayashi N, Wakasa T, Sakaguchi S, Krasznahorkay A, Murakami T, Nakatsuka N, Kaneko M, Matsuda Y, Mucher D, Reichert S, Bazin D, Lee J. Study of Gamow-Teller transitions from 132Sn via the ( p, n) reaction at 220 MeV/u in inverse kinematics. EPJ WEB OF CONFERENCES 2016. [DOI: 10.1051/epjconf/201610706003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
30
|
Blackmore T, Thomas I, McMahon R, Powell W, Hegarty M. Genetic-geographic correlation revealed across a broad European ecotypic sample of perennial ryegrass (Lolium perenne) using array-based SNP genotyping. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015; 128:1917-1932. [PMID: 26093611 PMCID: PMC4572065 DOI: 10.1007/s00122-015-2556-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 06/05/2015] [Indexed: 05/29/2023]
Abstract
Publically available SNP array increases the marker density for genotyping of forage crop, Lolium perenne. Applied to 90 European ecotypes composed of 716 individuals identifies a significant genetic-geographic correlation. Grassland ecosystems are ubiquitous across temperate and tropical regions, totalling 37% of the terrestrial land cover of the planet, and thus represent a global resource for understanding local adaptations to environment. However, genomic resources for grass species (outside cereals) are relatively poor. The advent of next-generation DNA sequencing and high-density SNP genotyping platforms enables the development of dense marker assays for population genetics analyses and genome-wide association studies. A high-density SNP marker resource (Illumina Infinium assay) for perennial ryegrass (Lolium perenne) was created and validated in a broad ecotype collection of 716 individuals sampled from 90 sites across Europe. Genetic diversity within and between populations was assessed. A strong correlation of geographic origin to genetic structure was found using principal component analysis, with significant correlation to longitude and latitude (P < 0.001). The potential of this array as a resource for studies of germplasm diversity and identifying traits underpinning adaptive variation is highlighted.
Collapse
|
31
|
Barua UM, Chalmers KJ, Thomas WT, Hackett CA, Lea V, Jack P, Forster BP, Waugh R, Powell W. Molecular mapping of genes determining height, time to heading, and growth habit in barley (Hordeum vulgare). Genome 2012; 36:1080-7. [PMID: 18470049 DOI: 10.1139/g93-143] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A combination of random amplified polymorphic DNA (RAPD) and restriction fragment length polymorphism (RFLP) markers has been used to locate genes controlling important developmental characters in barley. The denso dwarfing gene has been mapped to the long arm of chromosome 3H. Stepwise multiple regression was also used to identify another region of the barley genome (on chromosome 7H), which contributed to variation in height. The denso locus was shown to be associated with delaying time to heading. A protein (WSP2) and an RAPD marker on barley chromosomes 5H and 6H, respectively, were also associated with time to heading. These results are discussed in relation to the genetic analysis of developmentally important traits and the development of dwarfing genes in barley breeding programs.
Collapse
|
32
|
Lanham PG, Forster BP, McNicol P, Moss JP, Powell W. Seed storage protein variation in Arachis species. Genome 2012; 37:487-96. [PMID: 18470095 DOI: 10.1139/g94-068] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Seventy-two accessions, representing 22 species from sections Arachis, Erectoides, Extranervosae, and Triseminalae of the genus Arachis, were screened for seed storage protein polymorphism. Variation was detected between sections, between genome types, between species, and in some cases between different accessions of the same species or different seeds of the same accession. Arachis duranensis and one accession of A. cardenasii were found to have identical protein patterns. The greatest dissimilarity was found between species of the section Extranervosae and species of the section Triseminalae. Those of section Erectoides showed much similarity with some species of section Arachis. Protein polymorphism was shown to distinguish the two subspecies of A. hypogaea (fastigiata and hypogaea) in 27 of 28 cases. The seed protein profile of A. monticola was a combination of seed protein profiles from the two A. hypogaea subspecies. The relatedness between the various species was calculated and those that had the greatest similarity with A. hypogaea were A. spegazzinii and A. batizocoi.
Collapse
|
33
|
Swanston JS, Thomas WTB, Powell W, Meyer R, Bringhurst TA, Pearson SY, Brosnan JM, Broadhead A. Assessment of Spirit Yield in Barley Breeding Lines. JOURNAL OF THE INSTITUTE OF BREWING 2012. [DOI: 10.1002/j.2050-0416.2000.tb00040.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
34
|
Foster SP, Denholm I, Poppy GM, Thompson R, Powell W. Fitness trade-off in peach-potato aphids (Myzus persicae) between insecticide resistance and vulnerability to parasitoid attack at several spatial scales. BULLETIN OF ENTOMOLOGICAL RESEARCH 2011; 101:659-666. [PMID: 21205398 DOI: 10.1017/s0007485310000623] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Insecticide-resistant clones of the peach-potato aphid, Myzus persicae (Sulzer), have previously been shown to have a reduced response to aphid alarm pheromone compared to susceptible ones. The resulting vulnerability of susceptible and resistant aphids to attack by the primary endoparasitoid, Diaeretiella rapae (McIntosh), was investigated across three spatial scales. These scales ranged from aphids confined on individual leaves exposed to single female parasitoids, to aphids on groups of whole plants exposed to several parasitoids. In all experiments, significantly fewer aphids from insecticide-susceptible clones became parasitised compared to insecticide-resistant aphids. Investigations of aphid movement showed at the largest spatial scale that more susceptible aphids than resistant aphids moved from their inoculation leaves to other leaves on the same plant after exposure to parasitoids. The findings imply that parasitoids, and possibly other natural enemies, can influence the evolution and dynamics of insecticide resistance through pleiotropic effects of resistance genes on important behavioural traits.
Collapse
|
35
|
Althoen M, Moreno I, Powell W, Khoury P. Abstract No. 249: Embolization of Large Uterine Fibroids Retrospective Study. J Vasc Interv Radiol 2009. [DOI: 10.1016/j.jvir.2008.12.244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
|
36
|
Stamati K, Mackay I, Powell W. A quantitative genomic imbalance gene expression assay in a hexaploid species: wheat (Triticum aestivum). Genome 2009; 52:89-94. [DOI: 10.1139/g08-096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Responses to allopolyploidy include unequal expression of duplicated genes, gene silencing, and sometimes genomic rearrangements. In plants, the relationship between allelic expression differences arising from changes in regulatory regions and the resulting phenotype is poorly understood because of the complexity of their genomes and lack of efficient methodology to identify regulatory variation. Identifying functionally important regulatory variation in crops such as hexaploid wheat ( Triticum aestivum ) is in its infancy. More knowledge is required about the contribution of participatory genomes to its transcriptome. In this paper, we demonstrate the use of allelic imbalance assays to quantify relative expression levels across tissues and growth regimes of homoeologous transcripts of the A, B, and D genomes. Polymorphisms in the type I thionins have been used as an example. We show that expression levels vary markedly and interactively over all factors. For this gene, the B genome is the smallest contributor to the transcriptome and the D genome the largest. As additional sequence information is accumulated across genomes, this assay will allow the simple study of relative expression across multiple homeologous loci.
Collapse
|
37
|
Dawson IK, Powell W. Genetic variation in the Afromontane treePrunus africana, an endangered medicinal species. Mol Ecol 2008. [DOI: 10.1046/j.1365-294x.1999.00518.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
38
|
Traugott M, Bell JR, Broad GR, Powell W, van Veen FJF, Vollhardt IMG, Symondson WOC. Endoparasitism in cereal aphids: molecular analysis of a whole parasitoid community. Mol Ecol 2008; 17:3928-38. [PMID: 18662231 DOI: 10.1111/j.1365-294x.2008.03878.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Insect parasitoids play a major role in terrestrial food webs as they are highly diverse, exploit a wide range of niches and are capable of affecting host population dynamics. Formidable difficulties are encountered when attempting to quantify host-parasitoid and parasitoid-parasitoid trophic links in diverse parasitoid communities. Here we present a DNA-based approach to effectively track trophic interactions within an aphid-parasitoid food web, targeting, for the first time, the whole community of parasitoids and hyperparasitods associated with a single host. Using highly specific and sensitive multiplex and singleplex polymerase chain reaction, endoparasitism in the grain aphid Sitobion avenae (F) by 11 parasitoid species was quantified. Out of 1061 aphids collected during 12 weeks in a wheat field, 18.9% were found to be parasitized. Parasitoids responded to the supply of aphids, with the proportion of aphids parasitized increasing monotonically with date, until the aphid population crashed. In addition to eight species of primary parasitoids, DNA from two hyperparasitoid species was detected within 4.1% of the screened aphids, with significant hyperparasitoid pressure on some parasitoid species. In 68.2% of the hyperparasitized aphids, identification of the primary parasitoid host was also possible, allowing us to track species-specific parasitoid-hyperparasitoid links. Nine combinations of primary parasitoids within a single host were found, but only 1.6% of all screened aphids were multiparasitized. The potential of this approach to parasitoid food web research is discussed.
Collapse
|
39
|
Jones H, Leigh FJ, Mackay I, Bower MA, Smith LM, Charles MP, Jones G, Jones MK, Brown TA, Powell W. Population-Based Resequencing Reveals That the Flowering Time Adaptation of Cultivated Barley Originated East of the Fertile Crescent. Mol Biol Evol 2008; 25:2211-9. [DOI: 10.1093/molbev/msn167] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
40
|
White J, Law JR, MacKay I, Chalmers KJ, Smith JSC, Kilian A, Powell W. The genetic diversity of UK, US and Australian cultivars of Triticum aestivum measured by DArT markers and considered by genome. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 116:439-53. [PMID: 18060539 DOI: 10.1007/s00122-007-0681-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2007] [Accepted: 11/13/2007] [Indexed: 05/02/2023]
Abstract
The genetic diversity of UK, US and Australian wheat varieties over the period of modern plant breeding is estimated using diversity array technology markers. Diversity is assessed by both genetic distance between varieties, by AMOVA and as the volumes of multi-dimensional convex hulls estimated from principal co-ordinate analysis. At the whole genome level the three populations are genetically distinct; this is also true of the B genome. However, the US and Australian D genomes are found to occupy the same region of diversity space and the A genomes for these countries are partially overlapping. The use of high-density genotyping with a common marker set allows an unprecedented direct comparison between the diversities of the national populations, between individual genomes and the fluctuation of diversity over time. The highest genetic diversity amongst varieties is reported in the Australian population followed by the US, which in turn is more diverse than the UK. However the average diversity of loci is higher in the US set than in the Australian. Non-random fluctuations in genetic diversity over time are observed.
Collapse
|
41
|
Woodhead M, Russell J, Squirrell J, Hollingsworth PM, Mackenzie K, Gibby M, Powell W. Comparative analysis of population genetic structure in Athyrium distentifolium (Pteridophyta) using AFLPs and SSRs from anonymous and transcribed gene regions. Mol Ecol 2005; 14:1681-95. [PMID: 15836642 DOI: 10.1111/j.1365-294x.2005.02543.x] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
To examine the performance and information content of different marker systems, comparative assessment of population genetic diversity was undertaken in nine populations of Athyrium distentifolium using nine genomic and 10 expressed sequence tag (EST) microsatellite (SSR) loci, and 265 amplified fragment length polymorphism (AFLP) loci from two primer combinations. In range-wide comparisons (European vs. North American populations), the EST-SSR loci showed more reliable amplification and produced more easily scorable bands than genomic simple sequence repeats (SSRs). Genomic SSRs showed significantly higher levels of allelic diversity than EST-SSRs, but there was a significant correlation in the rank order of population diversities revealed by both marker types. When AFLPs, genomic SSRs, and EST-SSRs are considered, comparisons of different population diversity metrics/markers revealed a mixture of significant and nonsignificant rank-order correlations. However, no hard incongruence was detected (in no pairwise comparison of populations did different marker systems or metrics detect opposingly significant different amounts of variation). Comparable population pairwise estimates of F(ST) were obtained for all marker types, but whilst absolute values for genomic and EST-SSRs were very similar (F(ST) = 0.355 and 0.342, respectively), differentiation was consistently higher for AFLPs in pairwise and global comparisons (global AFLP F(ST) = 0.496). The two AFLP primer combinations outperformed 18 SSR loci in assignment tests and discriminatory power in phenetic cluster analyses. The results from marker comparisons on A. distentifolium are discussed in the context of the few other studies on natural plant populations comparing microsatellite and AFLP variability.
Collapse
|
42
|
Foster SP, Denholm I, Thompson R, Poppy GM, Powell W. Reduced response of insecticide-resistant aphids and attraction of parasitoids to aphid alarm pheromone; a potential fitness trade-off. BULLETIN OF ENTOMOLOGICAL RESEARCH 2005; 95:37-46. [PMID: 15705213 DOI: 10.1079/ber2004336] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Response to the alarm pheromone, (E)-beta-farnesene, produced by many species of aphids, was assessed in laboratory bioassays using an aphid pest, Myzus persicae (Sulzer), and its primary endoparasitoid, Diaeretiella rapae (McIntosh). This was done in three separate studies, the first investigating responses of a large number of M. persicae clones carrying different combinations of metabolic (carboxylesterase) and target site (kdr) insecticide resistance mechanisms, and the other two investigating the responses of young virgin female adult parasitoids. In M. persicae, both insecticide resistance mechanisms were associated with reduced repellence suggesting that each has a pleiotropic effect on aphid behaviour. In contrast, D. rapae females were attracted to the alarm pheromone source. The implications of this apparent fitness trade-off for the evolution and dynamics of insecticide resistance, and the potential for using beneficial insects to combat resistance development are discussed.
Collapse
|
43
|
Molina-Cano JL, Russell JR, Moralejo MA, Escacena JL, Arias G, Powell W. Chloroplast DNA microsatellite analysis supports a polyphyletic origin for barley. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2005; 110:613-619. [PMID: 15723272 DOI: 10.1007/s00122-004-1878-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2004] [Accepted: 11/10/2004] [Indexed: 05/24/2023]
Abstract
Five barley chloroplast DNA microsatellites (cpSSRs) were used to study genetic relationships among a set of 186 barley accessions-34 Hordeum vulgare ssp. spontaneum (HS accessions) from Morocco, Ethiopia, Cyprus, Crete, Libya, Iraq, Iran, Turkey, Afghanistan and Israel, 122 H. vulgare ssp. vulgare landraces (HV landraces) from Spain, Bolivia (old Spanish introductions), Morocco, Libya and Ethiopia and 20 modern European spring barleys (HV cultivars). All loci were polymorphic in the material studied, with the number of alleles per locus ranging from two to three. Fifteen multi-locus haplotypes were observed, 11 in HS accessions and seven in HV landraces and cultivars. Of the seven haplotypes found in the HV lines, three were shared with the HS accessions, and four were unique. Cluster analysis revealed two main groups, one consisting of HS accessions from Ethiopia and the HV landraces from Spain, Bolivia (old Spanish), Morocco and Ethiopia, whereas the other larger group contained all of the other accessions studied. Based on these grouping and the existence of haplotypes found in the HV landraces and cultivars but not in the HS wild barley, a polyphyletic origin is proposed for barley, with further centres of origin in Ethiopia and the Western Mediterranean.
Collapse
|
44
|
Moralejo M, Swanston JS, Muñoz P, Prada D, Elía M, Russell JR, Ramsay L, Cistué L, Codesal P, Casas AM, Romagosa I, Powell W, Molina-Cano JL. Use of new EST markers to elucidate the genetic differences in grain protein content between European and North American two-rowed malting barleys. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 110:116-125. [PMID: 15551038 DOI: 10.1007/s00122-004-1805-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2004] [Accepted: 08/24/2004] [Indexed: 05/24/2023]
Abstract
A population comprising 102 doubled haploid lines were produced from a cross between Beka, a barley cultivar widely grown in Spain, and Logan, a north American cultivar with inherently low protein content, a character considered to derive from the cultivar Karl. The intentions were to determine whether low-nitrogen malting barleys could be developed in Spain, and if genetic factors that influenced protein content were similarly expressed in widely diverse environments, i.e. northeastern Spain and eastern Scotland. An extensive map comprising 187 molecular markers was developed. Expressed sequence-tagged-derived markers were used in addition to anonymous simple sequence repeats to determine the potential for identifying candidate genes for quantitative trait loci (QTLs), and 22 such markers were mapped for the first time. There was transgressive segregation for both yield and protein content, and the gene for low protein from Logan was not expressed in the Scottish environment. In 2002, high yield was associated with earlier heading date in Spain, while late heading at the Scottish site was associated with greater lodging and lower thousand-kernel weight. These appeared to be possible pleiotropic effects of a factor detected on chromosome 2H. Using information from a consensus map, it was shown that this locus on 2H was in the region of the photoperiod response gene Eam6. A QTL explaining 18% of the variation in grain protein content was detected on chromosome 5H in a region in which a gene for nitrate reductase was previously observed. No effect on grain protein was associated with chromosome 6H, which has been suggested as the location of the low protein gene from Karl. However, it is likely that Karl contained more than one genetic factor reducing protein, and we postulate that the gene on 6H may have been lost during the breeding of Logan.
Collapse
|
45
|
Matus I, Corey A, Filichkin T, Hayes PM, Vales MI, Kling J, Riera-Lizarazu O, Sato K, Powell W, Waugh R. Development and characterization of recombinant chromosome substitution lines (RCSLs) using Hordeum vulgare subsp. spontaneum as a source of donor alleles in a Hordeum vulgare subsp. vulgare background. Genome 2004; 46:1010-23. [PMID: 14663520 DOI: 10.1139/g03-080] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ancestor of barley (Hordeum vulgare subsp. spontaneum) may be a source of novel alleles for crop improvement. We developed a set of recombinant chromosome substitution lines (RCSLs) using an accession of H. vulgare subsp. spontaneum (Caesarea 26-24, from Israel) as the donor and Hordeum vulgare subsp. vulgare 'Harrington' (the North American malting quality standard) as the recurrent parent via two backcrosses to the recurrent parent, followed by six generations of selfing. Here we report (i) the genomic architecture of the RCSLs, as inferred by simple sequence repeat (SSR) markers, and (ii) the effects of H. vulgare subsp. spontaneum genome segment introgressions in terms of three classes of phenotypes: inflorescence yield components, malting quality traits, and domestication traits. Significant differences among the RCSLs were detected for all phenotypes measured. The phenotypic effects of the introgressions were assessed using association analysis, and these were referenced to quantitative trait loci (QTL) reported in the literature. Hordeum vulgare subsp. spontaneum, despite its overall inferior phenotype, contributed some favorable alleles for agronomic and malting quality traits. In most cases, the introgression of the ancestral genome resulted in a loss of desirable phenotypes in the cultivated parent. Although disappointing from a plant breeding perspective, this finding may prove to be a useful tool for gene discovery.
Collapse
|
46
|
Graham J, Smith K, MacKenzie K, Jorgenson L, Hackett C, Powell W. The construction of a genetic linkage map of red raspberry (Rubus idaeus subsp. idaeus) based on AFLPs, genomic-SSR and EST-SSR markers. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 109:740-9. [PMID: 15127204 DOI: 10.1007/s00122-004-1687-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2003] [Accepted: 03/29/2004] [Indexed: 05/03/2023]
Abstract
Breeding in raspberry is time-consuming due to the highly heterozygous nature of this perennial fruit crop, coupled with relatively long periods of juvenility. The speed and precision of raspberry breeding can be improved by genetic linkage maps, thus facilitating the development of diagnostic markers for polygenic traits and the identification of genes controlling complex phenotypes. A genetic linkage map (789 cM) of the red raspberry Rubus idaeus has been constructed from a cross between two phenotypically different cultivars; the recent European cultivar Glen Moy and the older North American cultivar Latham. SSR markers were developed from both genomic and cDNA libraries from Glen Moy. These SSRs, together with AFLP markers, were utilised to create a linkage map. In order to test the utility of the genetic linkage map for QTL analysis, morphological data based on easily scoreable phenotypic traits were collected. The segregation of cane spininess, and the root sucker traits of density and spread from the mother plant, was quantified in two different environments. These traits were analysed for significant linkages to mapped markers using MapQTL and were found to be located on linkage group 2 for spines and group 8 for density and diameter. The availability of co-dominant markers allowed heterozygosities to be calculated for both cultivars.
Collapse
|
47
|
Provan J, Wolters P, Caldwell KH, Powell W. High-resolution organellar genome analysis of Triticum and Aegilops sheds new light on cytoplasm evolution in wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 108:1182-90. [PMID: 15067406 DOI: 10.1007/s00122-003-1538-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2003] [Accepted: 11/10/2003] [Indexed: 05/05/2023]
Abstract
We have utilised polymorphic chloroplast microsatellites to analyse cytoplasmic relationships between accessions in the genera Triticum and Aegilops. Sequencing of PCR products revealed point mutations and insertions/deletions in addition to the standard repeat length expansion/contraction which most likely represent ancient synapomorphies. Phylogenetic analyses revealed three distinct groups of accessions. One of these contained all the non- Aegilops speltoides S-type cytoplasm species, another comprised almost exclusively A, C, D, M, N, T and U cytoplasm-type accessions and the third contained the polyploid Triticum species and all the Ae. speltoides accessions, further confirming that Ae. speltoides or a closely related but now extinct species was the original B-genome donor of cultivated polyploid wheat. Successive decreases in levels of genetic diversity due to domestication were also observed. Finally, we highlight the importance of elucidating longer-term evolutionary processes operating at microsatellite repeat loci.
Collapse
|
48
|
Graham J, Hein I, Russell J, Woodhead M, Gordon S, Smith K, Jorgensen L, Brennan R, Powell W. THE USE OF GENOMICS TECHNOLOGIES IN CONTEMPORARY RUBUS ABD RIBES BREEDING PROGRAMMES. ACTA HORTICULTURAE 2004:319-322. [DOI: 10.17660/actahortic.2004.649.61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
|
49
|
Squirrell J, Woodhead M, Hollingsworth P, Russell J, Gibby M, Powell W. Isolation of Polymorphic Microsatellite Markers for the Alpine Lady Fern, Athyrium Distentifolium Tausch ex Opiz, from an Enriched Genomic Library. CONSERV GENET 2004. [DOI: 10.1023/b:coge.0000030027.93459.95] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
50
|
Wardrop J, Fuller J, Powell W, Machray GC. Exploiting plant somatic radiation hybrids for physical mapping of expressed sequence tags. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2004; 108:343-8. [PMID: 14513221 DOI: 10.1007/s00122-003-1434-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2003] [Accepted: 08/12/2003] [Indexed: 05/24/2023]
Abstract
Methods are described for the optimisation of the generation of radiation hybrids suitable for physical mapping of a plant (barley) genome. A combination of PCR-based technologies, involving the use of whole genome, mixed primer and hemi-nested primer amplifications, can greatly extend their utility for the physical mapping of expressed sequence tags (ESTs). Using panels of hybrids and ESTs, donor DNA retention and individual marker retention frequencies for the expressed portion of the barley genome in the hybrids were estimated.
Collapse
|