Academic literature on the topic 'Back cross Nested Association Mapping design'

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Journal articles on the topic "Back cross Nested Association Mapping design"

1

Zadro, Joshua. "Mapping the Association between Vitamin D and Low Back Pain: A Systematic Review and MetaAnalysis of Observational Studies." Pain Physician 7, no. 20;7 (November 13, 2017): 611–40. http://dx.doi.org/10.36076/ppj/2017.7.611.

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Background: Low back pain (LBP) is the highest contributor to disability worldwide, with current intervention strategies only providing small to moderate analgesic effects. The use of vitamin D supplementation for LBP has gained interest due to its proposed anti-inflammatory and neuromodulatory properties. However, it is still unclear whether vitamin D levels differ between those with and without LBP or if vitamin D levels are associated with pain intensity. Objectives: We aim to investigate the association between vitamin D levels and LBP and to determine if vitamin D levels correlate with pain intensity in individuals with LBP. Study Design: This study was conducted in accordance with the guidelines for performing a Metaanalysis and Systematic Review Of Observational Studies in Epidemiology (MOOSE). Methods: We performed electronic database searches combined keywords relating to vitamin D and LBP in MEDLINE, CINAHL, EMBASE, AMED, WEB OF SCIENCE, and SCOPUS from the earliest record to March 2017. Studies were included if they reported any quantitative measure of vitamin D, such as serum 25-hydroxyvitamin D [25(OH)D], with adequate data in patients with and without LBP or adequate data on pain intensity in patients with LBP. No restriction on the type or duration of LBP, nor the age and gender of patients was applied. Two reviewers independently performed the selection of studies, extracted data, and assessed the methodological quality of the included studies using a modified 15-item Downs and Black checklist. Results: After the removal of duplicates and the screening of titles and abstracts, 105 full texts were evaluated. There were 29 articles included in this systemic review (22 entered into a meta-analysis), including 19 cross-sectional studies, 9 case-control studies, and one single-arm surgical trial where the pre-operative data were used in our analyses. The pooled results from 19 studies showed that individuals with LBP were more likely to have vitamin D deficiency (pooled OR = 1.60, 95% CI: 1.20 - 2.12, P = 0.001, n = 19), severe deficiency (pooled OR = 2.08, 95% CI: 1.19 - 3.64, P = 0.010, n = 7), and lower serum concentrations of 25(OH)D (weighted MD = 3.86, 95% CI: 0.20 - 7.52, P = 0.039, n = 12) compared to those without LBP (where “n” is the number of studies). The association between vitamin D deficiency (pooled OR = 1.83, 95% CI: 1.26 - 2.66, P = 0.002, n = 9) or serum 25(OH)D (weighted MD = 7.64, 95% CI: 4.02 - 11.26, P < 0.001, n = 4) and LBP was stronger for women but failed to be statistically significant for men (pooled OR = 1.06, 95% CI: 0.62 - 1.81, P = 0.213, n = 3). In addition, there were strong associations between vitamin D deficiency and LBP in patients < 60 years old (particularly women). We found minimal evidence to support an association between vitamin D levels and pain intensity in patients with LBP. Limitations: We were unable to investigate whether vitamin D deficiency increases the risk of developing LBP as there were no longitudinal studies included in this review. Conclusion: Vitamin D deficiency is associated with LBP, with stronger associations observed in younger women and those with severe levels of deficiency. The association between vitamin D levels and pain intensity is inconsistent. These results may guide the implementation of future studies on vitamin D supplementation for LBP. PROSPERO Registration No: CRD42016046874. Key words: Vitamin D, low back pain, deficiency, pain intensity, serum 25-hydroxyvitamin D, supplementation, cross-sectional study, case-control study
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DJEMEL, A., M. C. ROMAY, P. REVILLA, L. KHELIFI, A. ORDÁS, and B. ORDÁS. "Genomic regions affecting fitness of the sweet corn mutant sugary1." Journal of Agricultural Science 151, no. 3 (April 19, 2012): 396–406. http://dx.doi.org/10.1017/s0021859612000391.

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SUMMARYMutants often reduce fitness when incorporated into some genotypes, as is the case of the mutant gene sugary1 (su1) in maize (Zea mays L.). Understanding the genetic factors affecting variation in the fitness of a mutant is of major interest from a theoretical point of view and also from a breeder's perspective. The genetic regulation of su1 behaviour was examined in two independent materials. First, populations of two recombinant inbred lines (RIL) were used, belonging to the Nested Association Mapping (NAM) design produced from crosses between the maize inbred B73 and two sweet corn lines (P39 and Il14h) that were genotyped with 1106 single nucleotide polymorphisms (SNPs). These RILs had a group of lines with the su1 allele and another group with the wild allele. At each marker, the allele frequencies of both groups of RILs were compared. Second, an F2 population derived from the cross between A619 (a field maize inbred line) and P39 (a sweet corn inbred line) was characterized with 295 simple sequence repeats (SSRs). In addition, the population was phenotyped for several traits related to viability. A large linkage block was detected around su1 in the RILs belonging to the NAM. Furthermore, significant genomic regions associated with su1 fitness were detected along the 10 maize chromosomes, although the detected effects were small. Quantitative trait loci (QTLs) with effects in multiple traits related to su1 fitness were detected in the F2 population, for example at bin 5·04. Therefore, the present results suggest that the su1 fitness depends on many genes of small effect distributed along the genome, with pleiotropic effects on multiple traits.
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Nasution, Achmad Delianur, and Eka Lestari Mahyuni. "The Impact of Work Method on Musculoskeletal Disorders Complaints in Pharmacy Unit." Disease Prevention and Public Health Journal 14, no. 2 (September 29, 2020): 81. http://dx.doi.org/10.12928/dpphj.v14i2.2478.

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Background: Musculoskeletal disorders (MSDs) are complaints on parts of skeletal muscle which is perceived by someone ranging from mild to severe. These complaints often occur in the manual process, heavy workload, and work environment interactions that may lead to a non-ergonomic work posture. This study aims to analyze the impact of the work method to MSDs complaints at the pharmacy unit of The University of Sumatera Utara Hospital. Method: This study is an observational survey using a cross-sectional design. The population was all workers in the pharmacy unit of the University of Sumatera Utara Hospital numbered 27 people. Samples were taken from the total population. Data were collected using camera media and direct observation of the work process that took place in the pharmacy unit of USU Hospital. Musculoskeletal complaints were obtained by mapping the pain using Nordic Body Map (NBM). The data obtained were analyzed using a simple logistic regression test to see the impact of the working methods of the pharmacy unit workers on their complaints of musculoskeletal disorders. Results: There was a significant association between work methods in the Pharmacy unit and the MSDs complaints with p-value = 0,001. This was supported by the mean of the work patterns in the pharmacy unit which have a heavy workload and the interaction with the layout according to anthropometry. There was a significant association between the work method causing musculoskeletal complaints when the drug compounding process (p = 0.000). It was evidenced from the result of NBM questionnaire that the three most prevalent complaints of MSDs were pain around the neck, back, and right shoulder. Conclusion: It can be concluded that the static working methods with a heavy workload must be accompanied by a relaxation to avoid burn out and fatigue.
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Sidhu, Karamjot, Dorothy Kim, David Lebel, Abdullah Alshammari, Gregory Photopoulos, Matias Pereira Duarte, Myriam Provost, et al. "Canadian Spine SocietyAbstract 57. Radiographic reporting in adolescent idiopathic scoliosis: Is there a discrepancy comparing radiologists’ reports and surgeons’ assessments?Abstract 74. How useful is prereferral spine imaging? A quality improvement projectAbstract 82. Early recovery after surgery, predictors of shorter length of stayAbstract 68. Gliding screws on early-onset scoliosis: a 5-year experienceAbstract 66. Reliability of radiographic assessment of growth modulation from anterior vertebral body tethering surgery in pediatric scoliosisAbstract 16. A dangerous curve: impact of the COVID-19 pandemic on brace treatment in adolescent idiopathic scoliosisAbstract 24. Development of a model of interprofessional support interventions to enhance brace adherence in adolescents with idiopathic scoliosisAbstract 94. Recognizing the importance of self-image in adult spinal deformity: results from the Prospective Evaluation of Elderly Deformity Surgery (PEEDS)Abstract 25. Assessing pain as a primary factor in the surgical treatment of adult spinal deformity surgery in patients over 60 years of ageAbstract 72. Application of the Ames-International Spine Study Group (AMES) radiographic modifiers to an asymptomatic population. Are the thresholds for “normal” appropriate?Abstract 109. Exploring the relationship between cannabis and narcotic use on preoperative health considerations in Canadian thoracolumbar patients: a CSORN studyAbstract 36. Metastatic spine disease: Should patients with short life expectancy be denied surgical care? An international retrospective cohort studyAbstract 91. What do patients expect of palliative treatment for symptomatic spinal metastases? A qualitative studyAbstract 44. Denosumab for giant cell tumours of the spine: molecular predictors of clinical response — a pilot studyAbstract 89. Surgical management and outcomes from “stable” degenerative spondylolisthesis (DS) from the CSORN prospective DS study: What the @#$ % are we doing?Abstract 33. Economic consequences of waiting for lumbar disc herniation surgeryAbstract 108. Motor recovery depends on timing of surgery in patients with lumbar disc herniationAbstract 106. Outcomes following revision decompression for lumbar spinal stenosis when compared to primary decompression: a matched cohort analysis using the Canadian Spine Outcomes and Research Network registryAbstract 64. Patient engagement, remote monitoring and virtual care — a pilot project in rural and remote patients undergoing elective lumbar surgeryAbstract 84. Development of a frailty index from the Canadian Spine Outcomes and Research Network (CSORN) to predict long-term success of surgery for patients with degenerative pathologies of the spineAbstract 102. Posterolateral versus posterior interbody fusion for the management of lumbar degenerative spondylolisthesis: analysis from the CSORN prospective LDS propensity score matched studyAbstract 31. Impact on patient-reported outcomes of ending the posterior construct proximally at C2 versus C3 in degenerative cervical myelopathy patientsAbstract 42. Perioperative factors predict 2-year trajectories of pain and disability following anterior cervical discectomy and fusionAbstract 61. Calculating utilities from the modified Japanese Orthopaedic Association score: a prerequisite for quantifying the value of care for cervical myelopathyAbstract 119. Serum neurofilament light (NF-L) and glial fibrillary acidic protein (GFAP) biomarkers and their association with MRI findings in human acute traumatic spinal cord injuryAbstract 95. The Montreal Acute Classification of Spinal Cord Injury (MAC-SCI): a new tool to detect and characterize spinal cord injury in the trauma patientAbstract 118. Mechanism of injury is associated with neurologic outcomes after cervical sensorimotor complete acute traumatic spinal cord injuryAbstract 13. Patient perspective: diagnosis and prognosis of acute spinal cord injuriesAbstract 136. Predictive analytics to improve dedicated spine trauma operating room resource allocationAbstract 138. Machine learning models to predict surgical resident workload at a level 1 trauma centreAbstract 139. Machine learning to predict duration of surgery and length of stay for single-level discectomy proceduresAbstract 9. Outpatient spinal surgery in ManitobaAbstract 131. Unexpected positive culture in presumed aseptic revision spine surgery: a systematic review and meta-analysisAbstract 50. Lumbar anterior vertebral body tethering: biomechanical assessment of the surgical decision factors influencing the immediate and 2 years postoperative correctionAbstract 145. Does prolonged symptom duration influence surgical outcomes for cervical radiculopathy?Abstract 147. A data-driven cluster analysis approach to create homogenous subgroups for traumatic spine injury: toward improving traditional classificationAbstract 41. The use of neo-adjuvant denosumab in treatment of giant cell tumours of the spineAbstract 5. Complications, revision rates and accuracy of robotic-guided S2 alar-iliac screw placementAbstract 6. Opioid use after spine surgery: How much are we over-prescribing?Abstract 7. Intradiscal injection of autologous bone marrow aspirate concentrate improves low back pain at 1 yearAbstract 8. Augmented reality–assisted spine surgery: an early experience demonstrating safety and accuracy with 218 screwsAbstract 22. Comparison of complications, revision rates and fluoroscopy time using the latest technology in robotic-guided surgery with historical fluoroscopic-guided controlsAbstract 23. Robotic-guided thoracolumbar fusion experience: a multi-surgeon, single-centre study of 628 patients and 3874 robotic-guided screws from 2012 to 2020Abstract 86. A province-wide assessment of the appropriateness of lumbar spine MRIAbstract 134. Concomitant traumatic spinal cord injury and brain injury diagnoses are more frequent and impactful than expectedAbstract 45. Spatial and depth mapping of nascent mineralization on Ti6Al4V surfaces demonstrating hierarchical macro-micro-nanoscale surface featuresAbstract 111. Propensity-matched outcomes comparing lumbar interbody fusion and total disk arthroplasty: a Canadian Spine Outcomes and Research Network (CSORN) studyAbstract 30. A Canadian-based pilot study of current surgical practice and implant preferences in lumbar fusion surgeryAbstract 32. Local contamination is a major cause of early deep wound infections following open posterior lumbosacral fusionsAbstract 99. Comparing patient preoperative expectations and postoperative expectation fulfillment between minimally invasive versus open fusion surgeryAbstract 146. Outpatient robotic-assisted lumbar spinal fusion using the Mazor X Stealth EditionAbstract 149. Lessons learned from my first 100 robotic-assisted lumbar fusions using the Mazor X Stealth Edition: surgical synergy with MIS, surgical navigation and roboticsAbstract 151. Freehand biomechanical testing for use in lumbar discectomy trainingAbstract 48. Spinal pathology and outcome post-THA: Does segment of arthrodesis matter?Abstract 27. Patient, surgical and institutional factors associated with length of stay in degenerative lumbar spine surgery: national multicentre cohort analysis from the Canadian Spine Outcomes and Research Network (CSORN)Abstract 28. The impact of the increasing proportion of degenerative spine emergency admissionsAbstract 51. Patient’s expectations of surgery for degenerative spondylolisthesis: analysis by site and type of surgery from the Canadian Spine Outcomes and Research Network (CSORN)Abstract 60. The impact of sex on thoracolumbar surgery outcomes in patients with diabetes — a CSORN studyAbstract 81. The impact of older age on rehabilitation outcomes following functional motor-incomplete traumatic spinal cord injuryAbstract 47. Devise and investigate a novel, intramuscular pressure based, muscle activation strategy in a spine stability modelAbstract 17. 3D radiologic outcomes for patients with moderate idiopathic scoliosis curves treated with internal (anterior vertebral growth modulation) versus external bracing: a 2-year observational studyAbstract 18. Is quality of life affected by concomitant isthmic spondylolisthesis when undergoing surgery for adolescent idiopathic scoliosis and nonsurgical management of the spondylolisthesis?Abstract 128. Toward macrostructural and microstructural investigation of the cervical spinal cord through quantitative analysis of T2-weighted and diffusion-weighted imagingAbstract 26. Minimally invasive versus open thoracolumbar spine surgery for patients who have lumbar spinal stenosis and an ASA score of 3 or above: a CSORN studyAbstract 101. Association between surgeon age and outcomes of spine surgery: a population-based retrospective cohort studyAbstract 77. Utilizing machine learning methodology to create a short form of the Multi-Morbidity Index in spinal cord injuryAbstract 70. Ten-year reoperation rate and clinical outcome in patients treated surgically for lumbar spinal stenosisAbstract 105. Assessing the importance of radiographic and clinical parameters when choosing decompression without fusion for LDS: results from the CSORN prospective DS studyAbstract 104. Preoperative cannabis use in Canadian thoracolumbar spine surgery patients: a CSORN studyAbstract 142. Post-traumatic ascending myelitis, about 2 cases, etiologic analysis and treatmentAbstract 55. NanoLOCK surfaces enhance osteoblast activities at the cellular levelAbstract 76. Which scoring system is the most accurate for predicting survival in patients undergoing surgery for spinal metastases from lung cancer?Abstract 11. Pedicle screw insertion using ultrasound-based navigation without intraoperative radiation: feasibility study on porcine cadaversAbstract 85. What barriers prevent patients being discharged from hospital following elective spine surgery?Abstract 15. Propensity-matched comparison of 90-day complications in robotic-assisted versus non-robotic-assisted lumbar fusionAbstract 56. No-tap (2-step) robotic-assisted cortical bone trajectory (RA-CBT) screw insertion is safe and efficient: comparative analysis of 179 patients and 924 RA-CBT screwsAbstract 124. Developing a Web-based application to promote the adoption of a clinical prediction model for independent walking in people with traumatic spinal cord injury — a protocolAbstract 125. Multivariable prediction models for prognostication after traumatic spinal cord injury — a systematic reviewAbstract 148. Expression of blood serum cytokines in the presentation of acute sciaticaAbstract 150. Do patient-reported outcome scores (PROs) correlate with bundled payment plan performance for elective spine surgeries?Abstract 46. Effects of delayed neurosurgery on anxiety, depression and economic burdenAbstract 69. Care close to home — a retrospective analysis of patients undergoing elective lumbar surgery in a rural satellite hospitalAbstract 110. Surgical adverse events for primary tumours of the spine and their impact on prognosis and outcomes: a PTRON studyAbstract 80. Spinal cord stimulation research in the restoration of function for individuals living with spinal cord injuries: a scoping reviewAbstract 132. Workup and management of asymptomatic extracranial traumatic vertebral artery injury: a Canadian Neurosurgery Resident Research Collaborative studyAbstract 12. A surgical treatment algorithm for restoring pelvic balance and health-related quality of life in high-grade lumbosacral spondylolisthesisAbstract 38. Effectiveness of 6 surgical approaches for minimally invasive lumbar interbody fusion: 1-year follow-up results from a global multicentre studyAbstract 39. Clinical outcomes and fusion success in patients with degenerative lumbar disease without spondylolisthesis: comparing anterolateral to posterior MIS approaches from a global multicentre studyAbstract 40. Anterolateral versus posterior approaches to minimally invasive interbody fusion for patients with spondylolisthesis: results at 1-year follow-up from a global multicentre studyAbstract 73. Benefit of minimally invasive lumbar interbody fusion versus traditional interbody fusion versus posterolateral spinal fusion in lumbar degenerative spondylolisthesis: a propensity-matched analysis from the CSORN prospective LDS studyAbstract 67. The effect of fusionless pediatric scoliosis surgery on 3D radiographic spinopelvic alignmentAbstract 62. Calculating utilities from the Neck Disability Index: a prerequisite for quantifying the value of cervical spine careAbstract 63. The psychometric properties of the mJOA for quality-of-life assessments in cervical myelopathyAbstract 59. Low radius of curvature growth friendly implants increases the risk of developing clinically significant proximal junctional kyphosisAbstract 144. Very long–term outcome of single-level minimally invasive lumbar microdiscectomy with a tubular retractorAbstract 112. Metal implant hypersensitivity in patients undergoing spinal surgery: a literature review and case reportAbstract 43. Diagnostic value of the lumbar spinal stenosis (SSHQ) survey in virtual care provided at a tertiary spine programAbstract 54. Is the Calgary Postoperative Pain After Spine Surgery (CAPPS) score correlated with long-term outcomes after lumbar fusion?Abstract 4. Development of a single-entry referral pathway for patients with spinal conditions in Manitoba: a cross-sectional review of impact and potential way forward for Canadian spine programsAbstract 113. Automatization of bone age calculationAbstract 123. An effectiveness and quality-of-life analysis of conservative care versus surgery for moderate and severe cervical myelopathyAbstract 133. Long-term survivorship of cervical spine procedures: a survivorship meta-analysis and meta-regressionAbstract 137. Natural history of degenerative cervical myelopathy: a meta-analysis and neurologic deterioration survival curve synthesisAbstract 14. Does intraoperative vancomycin powder affect postoperative infections in adolescent idiopathic scoliosis?Abstract 37. The clinical impact of nano-surface technology on postoperative opioid consumption in patients undergoing anterior lumbar interbody fusionAbstract 130. Design and implementation of a comprehensive perioperative complex spine communication toolAbstract 87. Stratifying low back pain patients in an inter-professional education and self-management model of care: results of a latent class analysisAbstract 88. Cohort accuracy versus confidence at the patient level: clinical challenges for AI-based prediction of low back pain outcomesAbstract 96. Preoperative disc angle is an important predictor of segmental lordosis after degenerative spondylolisthesis fusionAbstract 97. Preoperative depression, functional and radiographic outcomes after surgery for degenerative lumbar spondylolisthesisAbstract 116. A CSORN study of functional outcomes after surgery for lumbar degenerative spondylolisthesisAbstract 121. A CSORN study of the effect on radiographic alignment outcomes with different surgery type for degenerative lumbar spondylolisthesisAbstract 79. Spinal cord stimulation to restore neurological function: a costing analysisAbstract 107. Biomechanical properties of a novel morselized bone graft cageAbstract 93. Optimizing spine surgery instrument trays to immediately increase efficiency and reduce costs in the operating roomAbstract 103. Machine learning models can predict subsequent publication of North American Spine Society Annual General Meeting abstractsAbstract 117. The use of primary sacroiliac joint fusion for lower back pain due to sacroiliac joint pathology: a systematic review and meta-analysisAbstract 141. How to make the most of your operative time by optimizing surgical schedulingAbstract 126. Altering physician referral practices remains a challenge: a spine assessment clinic quality improvement studyAbstract 152. Outcomes of workers’ compensation patients undergoing neuromodulation for persistent neuropathic pain conditionsAbstract 90. Expectations of treatment outcomes in patients with spinal metastases: What do we tell our patients? A qualitative studyAbstract 52. Fluoroscopically guided radiofrequency ablation of the superior cluneal nerve: preliminary outcomes data for a minimally invasive approach for treating superior cluneal neuralgiaAbstract 21. Single-stage posterior approach for en bloc resection and spinal reconstruction of T4 Pancoast tumour invading spineAbstract 34. Predictors of sacral ulcers in patients with complete spinal cord injuryAbstract 135. Targeting geographic wait time disparities in Canada: a rapid review of domestic and international strategies to reduce orthopedic wait times in the MaritimesAbstract 143. The influence of coronal plane parameters on patient-reported outcome measures in patients undergoing decompression for lumbar spinal stenosis." Canadian Journal of Surgery 65, no. 6 Suppl 3 (December 9, 2022): S112—S164. http://dx.doi.org/10.1503/cjs.011622.

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Garin, Vincent, Chiaka Diallo, Mohamed Lamine Tékété, Korotimi Théra, Baptiste Guitton, Karim Dagno, Abdoulaye G. Diallo, et al. "Characterization of adaptation mechanisms in sorghum using a multireference back-cross nested association mapping design and envirotyping." GENETICS, February 21, 2024. http://dx.doi.org/10.1093/genetics/iyae003.

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Abstract Identifying the genetic factors impacting the adaptation of crops to environmental conditions is of key interest for conservation and selection purposes. It can be achieved using population genomics, and evolutionary or quantitative genetics. Here we present a sorghum multireference back-cross nested association mapping population composed of 3,901 lines produced by crossing 24 diverse parents to 3 elite parents from West and Central Africa-back-cross nested association mapping. The population was phenotyped in environments characterized by differences in photoperiod, rainfall pattern, temperature levels, and soil fertility. To integrate the multiparental and multi-environmental dimension of our data we proposed a new approach for quantitative trait loci (QTL) detection and parental effect estimation. We extended our model to estimate QTL effect sensitivity to environmental covariates, which facilitated the integration of envirotyping data. Our models allowed spatial projections of the QTL effects in agro-ecologies of interest. We utilized this strategy to analyze the genetic architecture of flowering time and plant height, which represents key adaptation mechanisms in environments like West Africa. Our results allowed a better characterization of well-known genomic regions influencing flowering time concerning their response to photoperiod with Ma6 and Ma1 being photoperiod-sensitive and the region of possible candidate gene Elf3 being photoperiod-insensitive. We also accessed a better understanding of plant height genetic determinism with the combined effects of phenology-dependent (Ma6) and independent (qHT7.1 and Dw3) genomic regions. Therefore, we argue that the West and Central Africa-back-cross nested association mapping and the presented analytical approach constitute unique resources to better understand adaptation in sorghum with direct application to develop climate-smart varieties.
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Wright, Tally I. C., Richard Horsnell, Bethany Love, Amanda J. Burridge, Keith A. Gardner, Robert Jackson, Fiona J. Leigh, et al. "A new winter wheat genetic resource harbors untapped diversity from synthetic hexaploid wheat." Theoretical and Applied Genetics 137, no. 3 (March 2024). http://dx.doi.org/10.1007/s00122-024-04577-1.

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Abstract Key message The NIAB_WW_SHW_NAM population, a large nested association mapping panel, is a useful resource for mapping QTL from synthetic hexaploid wheat that can improve modern elite wheat cultivars. Abstract The allelic richness harbored in progenitors of hexaploid bread wheat (Triticum aestivum L.) is a useful resource for addressing the genetic diversity bottleneck in modern cultivars. Synthetic hexaploid wheat (SHW) is created through resynthesis of the hybridisation events between the tetraploid (Triticum turgidum subsp. durum Desf.) and diploid (Aegilops tauschii Coss.) bread wheat progenitors. We developed a large and diverse winter wheat nested association mapping (NAM) population (termed the NIAB_WW_SHW_NAM) consisting of 3241 genotypes derived from 54 nested back-cross 1 (BC1) populations, each formed via back-crossing a different primary SHW into the UK winter wheat cultivar ‘Robigus’. The primary SHW lines were created using 15 T. durum donors and 47 Ae. tauschii accessions that spanned the lineages and geographical range of the species. Primary SHW parents were typically earlier flowering, taller and showed better resistance to yellow rust infection (Yr) than ‘Robigus’. The NIAB_WW_SHW_NAM population was genotyped using a single nucleotide polymorphism (SNP) array and 27 quantitative trait loci (QTLs) were detected for flowering time, plant height and Yr resistance. Across multiple field trials, a QTL for Yr resistance was found on chromosome 4D that corresponded to the Yr28 resistance gene previously reported in other SHW lines. These results demonstrate the value of the NIAB_WW_SHW_NAM population for genetic mapping and provide the first evidence of Yr28 working in current UK environments and genetic backgrounds. These examples, coupled with the evidence of commercial wheat breeders selecting promising genotypes, highlight the potential value of the NIAB_WW_SHW_NAM to variety improvement.
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Ryan, Robin Ann. "Forest as Place in the Album "Canopy": Culturalising Nature or Naturalising Culture?" M/C Journal 19, no. 3 (June 22, 2016). http://dx.doi.org/10.5204/mcj.1096.

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Every act of art is able to reveal, balance and revive the relations between a territory and its inhabitants (François Davin, Southern Forest Sculpture Walk Catalogue)Introducing the Understory Art in Nature TrailIn February 2015, a colossal wildfire destroyed 98,300 hectares of farm and bushland surrounding the town of Northcliffe, located 365 km south of Perth, Western Australia (WA). As the largest fire in the recorded history of the southwest region (Southern Forest Arts, After the Burn 8), the disaster attracted national attention however the extraordinary contribution of local knowledge in saving a town considered by authorities to be “undefendable” (Kennedy) is yet to be widely appreciated. In accounting for a creative scene that survived the conflagration, this case study sees culture mobilised as a socioeconomic resource for conservation and the healing of community spirit.Northcliffe (population 850) sits on a coastal plain that hosts majestic old-growth forest and lush bushland. In 2006, Southern Forest Arts (SFA) dedicated a Southern Forest Sculpture Walk for creative professionals to develop artworks along a 1.2 km walk trail through pristine native forest. It was re-branded “Understory—Art in Nature” in 2009; then “Understory Art in Nature Trail” in 2015, the understory vegetation layer beneath the canopy being symbolic of Northcliffe’s deeply layered caché of memories, including “the awe, love, fear, and even the hatred that these trees have provoked among the settlers” (Davin in SFA Catalogue). In the words of the SFA Trailguide, “Every place (no matter how small) has ‘understories’—secrets, songs, dreams—that help us connect with the spirit of place.”In the view of forest arts ecologist Kumi Kato, “It is a sense of place that underlies the commitment to a place’s conservation by its community, broadly embracing those who identify with the place for various reasons, both geographical and conceptual” (149). In bioregional terms such communities form a terrain of consciousness (Berg and Dasmann 218), extending responsibility for conservation across cultures, time and space (Kato 150). A sustainable thematic of place must also include livelihood as the third party between culture and nature that establishes the relationship between them (Giblett 240). With these concepts in mind I gauge creative impact on forest as place, and, in turn, (altered) forest’s impact on people. My abstraction of physical place is inclusive of humankind moving in dialogic engagement with forest. A mapping of Understory’s creative activities sheds light on how artists express physical environments in situated creative practices, clusters, and networks. These, it is argued, constitute unique types of community operating within (and beyond) a foundational scene of inspiration and mystification that is metaphorically “rising from the ashes.” In transcending disconnectedness between humankind and landscape, Understory may be understood to both culturalise nature (as an aesthetic system), and naturalise culture (as an ecologically modelled system), to build on a trope introduced by Feld (199). Arguably when the bush is cultured in this way it attracts consumers who may otherwise disconnect from nature.The trail (henceforth Understory) broaches the histories of human relations with Northcliffe’s natural systems of place. Sub-groups of the Noongar nation have inhabited the southwest for an estimated 50,000 years and their association with the Northcliffe region extends back at least 6,000 years (SFA Catalogue; see also Crawford and Crawford). An indigenous sense of the spirit of forest is manifest in Understory sculpture, literature, and—for the purpose of this article—the compilation CD Canopy: Songs for the Southern Forests (henceforth Canopy, Figure 1).As a cultural and environmental construction of place, Canopy sustains the land with acts of seeing, listening to, and interpreting nature; of remembering indigenous people in the forest; and of recalling the hardships of the early settlers. I acknowledge SFA coordinator and Understory custodian Fiona Sinclair for authorising this investigation; Peter Hill for conservation conversations; Robyn Johnston for her Canopy CD sleeve notes; Della Rae Morrison for permissions; and David Pye for discussions. Figure 1. Canopy: Songs for the Southern Forests (CD, 2006). Cover image by Raku Pitt, 2002. Courtesy Southern Forest Arts, Northcliffe, WA.Forest Ecology, Emotion, and ActionEstablished in 1924, Northcliffe’s ill-founded Group Settlement Scheme resulted in frontier hardship and heartbreak, and deforestation of the southwest region for little economic return. An historic forest controversy (1992-2001) attracted media to Northcliffe when protesters attempting to disrupt logging chained themselves to tree trunks and suspended themselves from branches. The signing of the Western Australian Regional Forest Agreement in 1999 was followed, in 2001, by deregulation of the dairy industry and a sharp decline in area population.Moved by the gravity of this situation, Fiona Sinclair won her pitch to the Manjimup Council for a sound alternative industry for Northcliffe with projections of jobs: a forest where artists could work collectively and sustainably to reveal the beauty of natural dimensions. A 12-acre pocket of allocated Crown Land adjacent to the town was leased as an A-Class Reserve vested for Education and Recreation, for which SFA secured unified community ownership and grants. Conservation protocols stipulated that no biomass could be removed from the forest and that predominantly raw, natural materials were to be used (F. Sinclair and P. Hill, personal interview, 26 Sep. 2014). With forest as prescribed image (wider than the bounded chunk of earth), Sinclair invited the artists to consider the themes of spirituality, creativity, history, dichotomy, and sensory as a basis for work that was to be “fresh, intimate, and grounded in place.” Her brief encouraged artists to work with humanity and imagination to counteract residual community divisiveness and resentment. Sinclair describes this form of implicit environmentalism as an “around the back” approach that avoids lapsing into political commentary or judgement: “The trail is a love letter from those of us who live here to our visitors, to connect with grace” (F. Sinclair, telephone interview, 6 Apr. 2014). Renewing community connections to local place is essential if our lives and societies are to become more sustainable (Pedelty 128). To define Northcliffe’s new community phase, artists respected differing associations between people and forest. A structure on a karri tree by Indigenous artist Norma MacDonald presents an Aboriginal man standing tall and proud on a rock to become one with the tree and the forest: as it was for thousands of years before European settlement (MacDonald in SFA Catalogue). As Feld observes, “It is the stabilizing persistence of place as a container of experiences that contributes so powerfully to its intrinsic memorability” (201).Adhering to the philosophy that nature should not be used or abused for the sake of art, the works resonate with the biorhythms of the forest, e.g. functional seats and shelters and a cascading retainer that directs rainwater back to the resident fauna. Some sculptures function as receivers for picking up wavelengths of ancient forest. Forest Folk lurk around the understory, while mysterious stone art represents a life-shaping force of planet history. To represent the reality of bushfire, Natalie Williamson’s sculpture wraps itself around a burnt-out stump. The work plays with scale as small native sundew flowers are enlarged and a subtle beauty, easily overlooked, becomes apparent (Figure 2). The sculptor hopes that “spiders will spin their webs about it, incorporating it into the landscape” (SFA Catalogue).Figure 2. Sundew. Sculpture by Natalie Williamson, 2006. Understory Art in Nature Trail, Northcliffe, WA. Image by the author, 2014.Memory is naturally place-oriented or at least place-supported (Feld 201). Topaesthesia (sense of place) denotes movement that connects our biography with our route. This is resonant for the experience of regional character, including the tactile, olfactory, gustatory, visual, and auditory qualities of a place (Ryan 307). By walking, we are in a dialogue with the environment; both literally and figuratively, we re-situate ourselves into our story (Schine 100). For example, during a summer exploration of the trail (5 Jan. 2014), I intuited a personal attachment based on my grandfather’s small bush home being razed by fire, and his struggle to support seven children.Understory’s survival depends on vigilant controlled (cool) burns around its perimeter (Figure 3), organised by volunteer Peter Hill. These burns also hone the forest. On 27 Sept. 2014, the charred vegetation spoke a spring language of opportunity for nature to reassert itself as seedpods burst and continue the cycle; while an autumn walk (17 Mar. 2016) yielded a fresh view of forest colour, patterning, light, shade, and sound.Figure 3. Understory Art in Nature Trail. Map Created by Fiona Sinclair for Southern Forest Sculpture Walk Catalogue (2006). Courtesy Southern Forest Arts, Northcliffe, WA.Understory and the Melody of CanopyForest resilience is celebrated in five MP3 audio tours produced for visitors to dialogue with the trail in sensory contexts of music, poetry, sculptures and stories that name or interpret the setting. The trail starts in heathland and includes three creek crossings. A zone of acacias gives way to stands of the southwest signature trees karri (Eucalyptus diversicolor), jarrah (Eucalyptus marginata), and marri (Corymbia calophylla). Following a sheoak grove, a riverine environment re-enters heathland. Birds, insects, mammals, and reptiles reside around and between the sculptures, rendering the earth-embedded art a fusion of human and natural orders (concept after Relph 141). On Audio Tour 3, Songs for the Southern Forests, the musician-composers reflect on their regionally focused items, each having been birthed according to a personal musical concept (the manner in which an individual artist holds the totality of a composition in cultural context). Arguably the music in question, its composers, performers, audiences, and settings, all have a role to play in defining the processes and effects of forest arts ecology. Local musician Ann Rice billeted a cluster of musicians (mostly from Perth) at her Windy Harbour shack. The energy of the production experience was palpable as all participated in on-site forest workshops, and supported each other’s items as a musical collective (A. Rice, telephone interview, 2 Oct. 2014). Collaborating under producer Lee Buddle’s direction, they orchestrated rich timbres (tone colours) to evoke different musical atmospheres (Table 1). Composer/Performer Title of TrackInstrumentation1. Ann RiceMy Placevocals/guitars/accordion 2. David PyeCicadan Rhythmsangklung/violin/cello/woodblocks/temple blocks/clarinet/tapes 3. Mel RobinsonSheltervocal/cello/double bass 4. DjivaNgank Boodjakvocals/acoustic, electric and slide guitars/drums/percussion 5. Cathie TraversLamentaccordion/vocals/guitar/piano/violin/drums/programming 6. Brendon Humphries and Kevin SmithWhen the Wind First Blewvocals/guitars/dobro/drums/piano/percussion 7. Libby HammerThe Gladevocal/guitar/soprano sax/cello/double bass/drums 8. Pete and Dave JeavonsSanctuaryguitars/percussion/talking drum/cowbell/soprano sax 9. Tomás FordWhite Hazevocal/programming/guitar 10. David HyamsAwakening /Shaking the Tree /When the Light Comes guitar/mandolin/dobro/bodhran/rainstick/cello/accordion/flute 11. Bernard CarneyThe Destiny Waltzvocal/guitar/accordion/drums/recording of The Destiny Waltz 12. Joel BarkerSomething for Everyonevocal/guitars/percussion Table 1. Music Composed for Canopy: Songs for the Southern Forests.Source: CD sleeve and http://www.understory.com.au/art.php. Composing out of their own strengths, the musicians transformed the geographic region into a living myth. As Pedelty has observed of similar musicians, “their sounds resonate because they so profoundly reflect our living sense of place” (83-84). The remainder of this essay evidences the capacity of indigenous song, art music, electronica, folk, and jazz-blues to celebrate, historicise, or re-imagine place. Firstly, two items represent the phenomenological approach of site-specific sensitivity to acoustic, biological, and cultural presence/loss, including the materiality of forest as a living process.“Singing Up the Land”In Aboriginal Australia “there is no place that has not been imaginatively grasped through song, dance and design, no place where traditional owners cannot see the imprint of sacred creation” (Rose 18). Canopy’s part-Noongar language song thus repositions the ancient Murrum-Noongar people within their life-sustaining natural habitat and spiritual landscape.Noongar Yorga woman Della Rae Morrison of the Bibbulmun and Wilman nations co-founded The Western Australian Nuclear Free Alliance to campaign against the uranium mining industry threatening Ngank Boodjak (her country, “Mother Earth”) (D.R. Morrison, e-mail, 15 July 2014). In 2004, Morrison formed the duo Djiva (meaning seed power or life force) with Jessie Lloyd, a Murri woman of the Guugu Yimidhirr Nation from North Queensland. After discerning the fundamental qualities of the Understory site, Djiva created the song Ngank Boodjak: “This was inspired by walking the trail […] feeling the energy of the land and the beautiful trees and hearing the birds. When I find a spot that I love, I try to feel out the lay-lines, which feel like vortexes of energy coming out of the ground; it’s pretty amazing” (Morrison in SFA Canopy sleeve) Stanza 1 points to the possibilities of being more fully “in country”:Ssh!Ni dabarkarn kooliny, ngank boodja kookoorninyListen, walk slowly, beautiful Mother EarthThe inclusion of indigenous language powerfully implements an indigenous interpretation of forest: “My elders believe that when we leave this life from our physical bodies that our spirit is earthbound and is living in the rocks or the trees and if you listen carefully you might hear their voices and maybe you will get some answers to your questions” (Morrison in SFA Catalogue).Cicadan Rhythms, by composer David Pye, echoes forest as a lively “more-than-human” world. Pye took his cue from the ambient pulsing of male cicadas communicating in plenum (full assembly) by means of airborne sound. The species were sounding together in tempo with individual rhythm patterns that interlocked to create one fantastic rhythm (Australian Broadcasting Corporation, Composer David Pye). The cicada chorus (the loudest known lovesong in the insect world) is the unique summer soundmark (term coined by Truax Handbook, Website) of the southern forests. Pye chased various cicadas through Understory until he was able to notate the rhythms of some individuals in a patch of low-lying scrub.To simulate cicada clicking, the composer set pointillist patterns for Indonesian anklung (joint bamboo tubes suspended within a frame to produce notes when the frame is shaken or tapped). Using instruments made of wood to enhance the rich forest imagery, Pye created all parts using sampled instrumental sounds placed against layers of pre-recorded ambient sounds (D. Pye, telephone interview, 3 Sept. 2014). He takes the listener through a “geographical linear representation” of the trail: “I walked around it with a stopwatch and noted how long it took to get through each section of the forest, and that became the musical timing of the various parts of the work” (Pye in SFA Canopy sleeve). That Understory is a place where reciprocity between nature and culture thrives is, likewise, evident in the remaining tracks.Musicalising Forest History and EnvironmentThree tracks distinguish Canopy as an integrative site for memory. Bernard Carney’s waltz honours the Group Settlers who battled insurmountable terrain without any idea of their destiny, men who, having migrated with a promise of owning their own dairy farms, had to clear trees bare-handedly and build furniture from kerosene tins and gelignite cases. Carney illuminates the culture of Saturday night dancing in the schoolroom to popular tunes like The Destiny Waltz (performed on the Titanic in 1912). His original song fades to strains of the Victor Military Band (1914), to “pay tribute to the era where the inspiration of the song came from” (Carney in SFA Canopy sleeve). Likewise Cathie Travers’s Lament is an evocation of remote settler history that creates a “feeling of being in another location, other timezone, almost like an endless loop” (Travers in SFA Canopy sleeve).An instrumental medley by David Hyams opens with Awakening: the morning sun streaming through tall trees, and the nostalgic sound of an accordion waltz. Shaking the Tree, an Irish jig, recalls humankind’s struggle with forest and the forces of nature. A final title, When the Light Comes, defers to the saying by conservationist John Muir that “The wrongs done to trees, wrongs of every sort, are done in the darkness of ignorance and unbelief, for when the light comes the heart of the people is always right” (quoted by Hyams in SFA Canopy sleeve). Local musician Joel Barker wrote Something for Everyone to personify the old-growth karri as a king with a crown, with “wisdom in his bones.”Kevin Smith’s father was born in Northcliffe in 1924. He and Brendon Humphries fantasise the untouchability of a maiden (pre-human) moment in a forest in their song, When the Wind First Blew. In Libby Hammer’s The Glade (a lover’s lament), instrumental timbres project their own affective languages. The jazz singer intended the accompanying double bass to speak resonantly of old-growth forest; the cello to express suppleness and renewal; a soprano saxophone to impersonate a bird; and the drums to imitate the insect community’s polyrhythmic undercurrent (after Hammer in SFA Canopy sleeve).A hybrid aural environment of synthetic and natural forest sounds contrasts collision with harmony in Sanctuary. The Jeavons Brothers sampled rustling wind on nearby Mt Chudalup to absorb into the track’s opening, and crafted a snare groove for the quirky eco-jazz/trip-hop by banging logs together, and banging rocks against logs. This imaginative use of percussive found objects enhanced their portrayal of forest as “a living, breathing entity.”In dealing with recent history in My Place, Ann Rice cameos a happy childhood growing up on a southwest farm, “damming creeks, climbing trees, breaking bones and skinning knees.” The rich string harmonies of Mel Robinson’s Shelter sculpt the shifting environment of a brewing storm, while White Haze by Tomás Ford describes a smoky controlled burn as “a kind of metaphor for the beautiful mystical healing nature of Northcliffe”: Someone’s burning off the scrubSomeone’s making sure it’s safeSomeone’s whiting out the fearSomeone’s letting me breathe clearAs Sinclair illuminates in a post-fire interview with Sharon Kennedy (Website):When your map, your personal map of life involves a place, and then you think that that place might be gone…” Fiona doesn't finish the sentence. “We all had to face the fact that our little place might disappear." Ultimately, only one house was lost. Pasture and fences, sheds and forest are gone. Yet, says Fiona, “We still have our town. As part of SFA’s ongoing commission, forest rhythm workshops explore different sound properties of potential materials for installing sound sculptures mimicking the surrounding flora and fauna. In 2015, SFA mounted After the Burn (a touring photographic exhibition) and Out of the Ashes (paintings and woodwork featuring ash, charcoal, and resin) (SFA, After the Burn 116). The forthcoming community project Rising From the Ashes will commemorate the fire and allow residents to connect and create as they heal and move forward—ten years on from the foundation of Understory.ConclusionThe Understory Art in Nature Trail stimulates curiosity. It clearly illustrates links between place-based social, economic and material conditions and creative practices and products within a forest that has both given shelter and “done people in.” The trail is an experimental field, a transformative locus in which dedicated physical space frees artists to culturalise forest through varied aesthetic modalities. Conversely, forest possesses agency for naturalising art as a symbol of place. Djiva’s song Ngank Boodjak “sings up the land” to revitalise the timelessness of prior occupation, while David Pye’s Cicadan Rhythms foregrounds the seasonal cycle of entomological music.In drawing out the richness and significance of place, the ecologically inspired album Canopy suggests that the community identity of a forested place may be informed by cultural, economic, geographical, and historical factors as well as endemic flora and fauna. Finally, the musical representation of place is not contingent upon blatant forms of environmentalism. The portrayals of Northcliffe respectfully associate Western Australian people and forests, yet as a place, the town has become an enduring icon for the plight of the Universal Old-growth Forest in all its natural glory, diverse human uses, and (real or perceived) abuses.ReferencesAustralian Broadcasting Commission. “Canopy: Songs for the Southern Forests.” Into the Music. Prod. Robyn Johnston. Radio National, 5 May 2007. 12 Aug. 2014 <http://www.abc.net.au/radionational/programs/intothemusic/canopy-songs-for-the-southern-forests/3396338>.———. “Composer David Pye.” Interview with Andrew Ford. The Music Show, Radio National, 12 Sep. 2009. 30 Jan. 2015 <http://canadapodcasts.ca/podcasts/MusicShowThe/1225021>.Berg, Peter, and Raymond Dasmann. “Reinhabiting California.” Reinhabiting a Separate Country: A Bioregional Anthology of Northern California. Ed. Peter Berg. San Francisco: Planet Drum, 1978. 217-20.Crawford, Patricia, and Ian Crawford. Contested Country: A History of the Northcliffe Area, Western Australia. Perth: UWA P, 2003.Feld, Steven. 2001. “Lift-Up-Over Sounding.” The Book of Music and Nature: An Anthology of Sounds, Words, Thoughts. Ed. David Rothenberg and Marta Ulvaeus. Middletown, CT: Wesleyan UP, 2001. 193-206.Giblett, Rod. People and Places of Nature and Culture. Bristol: Intellect, 2011.Kato, Kumi. “Addressing Global Responsibility for Conservation through Cross-Cultural Collaboration: Kodama Forest, a Forest of Tree Spirits.” The Environmentalist 28.2 (2008): 148-54. 15 Apr. 2014 <http://link.springer.com/article/10.1007/s10669-007-9051-6#page-1>.Kennedy, Sharon. “Local Knowledge Builds Vital Support Networks in Emergencies.” ABC South West WA, 10 Mar. 2015. 26 Mar. 2015 <http://www.abc.net.au/local/stories/2015/03/09/4193981.htm?site=southwestwa>.Morrison, Della Rae. E-mail. 15 July 2014.Pedelty, Mark. Ecomusicology: Rock, Folk, and the Environment. Philadelphia, PA: Temple UP, 2012.Pye, David. Telephone interview. 3 Sep. 2014.Relph, Edward. Place and Placelessness. London: Pion, 1976.Rice, Ann. Telephone interview. 2 Oct. 2014.Rose, Deborah Bird. Nourishing Terrains: Australian Aboriginal Views of Landscape and Wilderness. Australian Heritage Commission, 1996.Ryan, John C. Green Sense: The Aesthetics of Plants, Place and Language. Oxford: Trueheart Academic, 2012.Schine, Jennifer. “Movement, Memory and the Senses in Soundscape Studies.” Canadian Acoustics: Journal of the Canadian Acoustical Association 38.3 (2010): 100-01. 12 Apr. 2016 <http://jcaa.caa-aca.ca/index.php/jcaa/article/view/2264>.Sinclair, Fiona. Telephone interview. 6 Apr. 2014.Sinclair, Fiona, and Peter Hill. Personal Interview. 26 Sep. 2014.Southern Forest Arts. Canopy: Songs for the Southern Forests. CD coordinated by Fiona Sinclair. Recorded and produced by Lee Buddle. Sleeve notes by Robyn Johnston. West Perth: Sound Mine Studios, 2006.———. Southern Forest Sculpture Walk Catalogue. Northcliffe, WA, 2006. Unpaginated booklet.———. Understory—Art in Nature. 2009. 12 Apr. 2016 <http://www.understory.com.au/>.———. Trailguide. Understory. Presented by Southern Forest Arts, n.d.———. After the Burn: Stories, Poems and Photos Shared by the Local Community in Response to the 2015 Northcliffe and Windy Harbour Bushfire. 2nd ed. Ed. Fiona Sinclair. Northcliffe, WA., 2016.Truax, Barry, ed. Handbook for Acoustic Ecology. 2nd ed. Cambridge Street Publishing, 1999. 10 Apr. 2016 <http://www.sfu.ca/sonic-studio/handbook/Soundmark.html>.
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Dissertations / Theses on the topic "Back cross Nested Association Mapping design"

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Thera, Korotimi. "Analyse des déterminants génétiques contrôlant la production et la composition de la tige chez le sorgho (Sorghum bicolor [L.] Moench). Intégration des approches bi-et multi-parentales." Electronic Thesis or Diss., Montpellier, SupAgro, 2017. http://www.theses.fr/2017NSAM0030.

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Le sorgho est une des espèces de céréales les plus importantes au niveau mondial en termes d’alimentation humaine et animale. En outre, de nouvelles voies de valorisations liées à son haut potentiel de production de biomasse émergent (énergie, biomatériaux) avec des possibilités d’applications aux niveaux des pays du Nord et du Sud. L’identification des facteurs génétiques contrôlant la variabilité de la production et de la qualité de la biomasse est un des vecteurs de développement de variétés adaptées aux différentes utilisations. Actuellement, seule une vision partielle de l’architecture génétique de la production et de la qualité de la biomasse est disponible, pénalisant l’efficacité des programmes de sélection. Les principales raisons qui peuvent être évoquées sont : l’utilisation quasi exclusive de populations à base génétique très étroite (population biparentales correspondant à des idéotypes peu divers) et un manque de compréhension des interactions existantes entre la qualité de la biomasse et la phénologie. Dans ce contexte, cette thèse s’est articulée autour de 3 objectifs : i) apporter une meilleure compréhension du déterminisme génétique de la durée du cycle « semis - floraison » et de la hauteur des plantes dans le contexte de variétés sensibles à la photopériode, lesquelles ont été relativement peu travaillées jusqu’à présent , ii) analyser les interactions entre la qualité de la biomasse, la croissance en hauteur, la durée du cycle et la sensibilité au photopériodisme et iii) affiner notre compréhension des mécanismes moléculaires impliqués dans la variation de la qualité de la biomasse. Pour mener à bien ces analyses, deux populations de cartographie biparentales, un panel de diversité correspondant aux 35 parents d’un schéma de croisement multiparental (Backcross Nested Association Mapping) ainsi que leurs descendances (29 populations totalisant environ 1200 BC1F4) ont été caractérisés en termes de croissance, de phénologie et de qualité de la biomasse. L’analyse du déterminisme génétique de la phénologie couplée à une approche de modélisation écophysiologique a permis la mise en évidence d’une région chromosomique contrôlant une large part de la variabilité de la photopériode critique. Le gène ELF3 pour lequel plusieurs évidences fonctionnelles ont été mises en évidence chez d’autres espèces, est un candidat potentiel pour expliquer cet effet. Outre une large convergence entre les zones détectées pour la phénologie au sein de cette thèse et les études précédentes, une forte instabilité des zones détectées en fonction des conditions environnementales (dates de semis, année) a été mise en évidence. L’analyse des relations entre la qualité de la biomasse, la croissance en hauteur, la précocité et la sensibilité à la photopériode a mis en évidence des effets important du nanisme et de la date de semis sur la composition des tiges et des relations entre ses composantes. En outre, des différences de réactions à la variabilité des dates des semis ont été observées en fonction de la sensibilité à la photopériode des génotypes considérés. Enfin, la caractérisation de la composition biochimique des tiges (teneur en cellulose, en hémicellulose et en lignine des parois) au sein des 29 populations BC1F4, a mis en évidence de nombreuses zones chromosomiques pour lesquelles des gènes potentiellement causatifs ont été proposés. Ces analyses ont permis d’alimenter un répertoire de régions chromosomiques contrôlant les caractères cibles de la sélection. Les potentialités de ces résultats et des populations développées (bi- et multiparentales) dans le contexte de la sélection ainsi que de la validation des gènes sous-jacents à ces zones sont discutées
Sorghum ranks fifth in terms of grain production at the worldwide level. It contributes to food security in the developing countries and provides a significant share of the animal caloric intake. In addition sorghum is expected to contribute significantly to the emerging energy and biomaterial value chains. In this context, identification of the genetic factors controlling biomass production and quality is of crucial interest to develop varieties fitting the expectations of the different uses. Currently only a partial vision of the genetic architecture of biomass production and quality is available, hampering optimal breeding efficiencies. This can be explained by a limited use of the genetic diversity pool to dissect the genetic control of the traits of interest (mainly restricted to non-photoperiod sensitive varieties until now) and a limited understanding of the relationships between biomass production (largely driven by phenology variability) and quality. In this context, this PhD aimed at i) providing a better understanding of the genetic bases of flowering and height variabilities using photoperiod sensitive genetic material ii) disentangling the interactions between biomass quality, height, cycle duration and photoperiod sensitivity and iii) refining our understanding of the molecular mechanisms involved in the variation in biomass quality. To tackle these challenges, two biparental QTL mapping populations, a diversity panel including 35 parents of a Backcross Nested Association Mapping design and a subset of their progenies (29 populations encompassing a total of 1200 BC1F4) were characterized for their phenology, growth and biomass composition. The analysis of the genetic determinism of phenology coupled with an ecophysiological modeling approach, revealed a chromosomic region controlling a large part of the variability (60%) of critical photoperiod (a component of cycle duration). The gene ELF3, for which functional evidence of impact on photoperiod sensitivity is available in other species can be proposed as a functional driver of the variability induced by this region. Although a significant proportion of the genomic regions detected in this study have already been revealed in previous studies, several new regions have been discovered, underlying the interest of multiparental based designs. Phenology analyses over different sowing dates highlighted the complexity of the genetic determinism of this trait through the detection of genomic regions with variable effects. In depth analyses of biomass quality relationships with height, precocity and photoperiod sensitivity underlined strong dwarfism and sowing dates effects on the components of biomass quality and their relationships. In addition, different behaviors of photoperidiod sensitive and insensitive genotypes to delayed sowing dates have been observed. Finally, characterization of stem biochemical composition (cellulose, hemicellulose and lignin content of the cell walls) on the 29 BC1F4 populations, revealed numerous chromosomic regions with variable effects. Putative candidate genes from these regions of interest have been opposed. These analyses enriched a library of regions impacting the breeding targets linked to biomass production and quality. The potentials of these results and of the populations developed towards optimization of breeding efficiency and gene function validation have been discussed
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