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Nested Association Mapping
Nested association mapping (NAM) is a technique designed by the labs of Edward BucklerJames Holland anfor identifying and dissecting the genetic architecture of complex traits in corn (''Zea mays''). It is important to note that nested association mapping (unlike association mapping) is a specific technique that cannot be performed outside of a specifically designed population such as the Maize NAM population, the details of which are described below. Theory behind NAM NAM was created as a means of combining the advantages and eliminating the disadvantages of two traditional methods for identifying quantitative trait loci: linkage analysis and association mapping. Linkage analysis depends upon recent genetic recombination between two different plant lines (as the result of a genetic cross) to identify general regions of interest, with the advantage of requiring few genetic markers to ensure genome wide coverage and high statistical power per allele. Linkage analysis, however, has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Buckler
Edward S. Buckler is a plant geneticist with the USDA Agricultural Research Service and holds an adjunct appointment at Cornell University. His work focuses on both quantitative and statistical genetics in maize as well as other crops such as cassava. He originated the concept of Nested association mapping and created the first population designed for this type of quantitative genetic analysis. Buckler was elected an American Association for the Advancement of Science Fellow in 2012. In 2014, he was elected to the National Academy of Sciences. In 2017, he received the NAS prize in Food and Agricultural Science for his work using natural genetic diversity to develop varieties of maize with fifteen times more vitamin A than existing varieties. Career Buckler spent his childhood in Arlington, Virginia, where his mother worked as a microbiologist and his father worked for the US Navy. He is dyslexic and did not read until the second grade. He attended the University of Virginia, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Food Security
Food security speaks to the availability of food in a country (or geography) and the ability of individuals within that country (geography) to access, afford, and source adequate foodstuffs. According to the United Nations' Committee on World Food Security, food security is defined as meaning that all people, at all times, have physical, social, and economic access to sufficient, safe, and nutritious food that meets their food preferences and dietary needs for an active and healthy life. The availability of food irrespective of class, gender or region is another element of food security. There is evidence of food security being a concern many thousands of years ago, with central authorities in ancient China and ancient Egypt being known to release food from storage in times of famine. At the 1974 World Food Conference, the term "food security" was defined with an emphasis on supply; food security is defined as the "availability at all times of adequate, nourishing, diverse, bal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Candidate Gene
The candidate gene approach to conducting genetic association studies focuses on associations between genetic variation within pre-specified genes of interest, and phenotypes or disease states. This is in contrast to genome-wide association studies (GWAS), which is a hypothesis-free approach that scans the entire genome for associations between common genetic variants (typically SNPs) and traits of interest. Candidate genes are most often selected for study based on ''a priori'' knowledge of the gene's biological functional impact on the trait or disease in question. The rationale behind focusing on allelic variation in specific, biologically relevant regions of the genome is that certain alleles within a gene may directly impact the function of the gene in question and lead to variation in the phenotype or disease state being investigated. This approach often uses the case-control study design to try to answer the question, "Is one allele of a candidate gene more frequently seen in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Reviews (publisher)
Annual Reviews is an independent, non-profit academic publishing company based in San Mateo, California. As of 2021, it publishes 51 journals of review articles and ''Knowable Magazine'', covering the fields of life, biomedical, physical, and social sciences. Review articles are usually “peer-invited” solicited submissions, often planned one to two years in advance, which go through a peer-review process. The organizational structure has three levels: a volunteer board of directors, editorial committees of experts for each journal, and paid employees. Annual Reviews' stated mission is to synthesize and integrate knowledge "for the progress of science and the benefit of society". The first Annual Reviews journal, the ''Annual Review of Biochemistry'', was published in 1932 under the editorship of Stanford University chemist J. Murray Luck, who wanted to create a resource that provided critical reviews on contemporary research. The second journal was added in 1939. By ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annual Review Of Plant Biology
''Annual Review of Plant Biology'' is a peer-reviewed scientific journal published by Annual Reviews. It was first published in 1950 as the ''Annual Review of Plant Physiology''. Sabeeha Merchant has been the editor since 2005, making her the longest-serving editor in the journal's history after Winslow Briggs (1973–1993). As of 2022, ''Journal Citation Reports'' lists the journal's 2021 impact factor as 28.310, ranking it first of 238 journal titles in the category "Plant Sciences". History Beginning in 1947, the publishing nonprofit Annual Reviews began asking plant physiologists if it would be useful to have an annual journal that published review articles summarizing the recent literature in the field. Responses indicated that this would be very favorable, and the ''Annual Review of Plant Physiology'' published its first volume in 1950. Its founding editor was Daniel I. Arnon. It was thus the seventh journal title to be published by Annual Reviews. Its scope was somewh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Corn Leaf Blight
Northern corn leaf blight (NCLB) or Turcicum leaf blight (TLB) is a foliar disease of corn (maize) caused by ''Exserohilum turcicum'', the anamorph of the ascomycete '' Setosphaeria turcica''. With its characteristic cigar-shaped lesions, this disease can cause significant yield loss in susceptible corn hybrids. Hosts and symptoms Lesions can eventually expand to a more oblong or “cigar” shape. They may also coalesce to form large areas of necrotic tissue. There are several host-specific forms of ''E. turcicum''. The most economically important host is corn, but other forms may infect sorghum, Johnson grass, or sudangrass. The most common diagnostic symptom of the disease on corn is cigar-shaped or elliptical necrotic gray-green lesions on the leaves that range from one to seven inches long. These lesions may first appear as narrow, tan streaks that run parallel to the leaf veins. Fully developed lesions typically have a sooty appearance during humid weather, as a result of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Corn Leaf Blight
Southern corn leaf blight (SCLB) is a fungal disease of maize caused by the plant pathogen '' Bipolaris maydis'' (also known as '' Cochliobolus heterostrophus'' in its teleomorph state). The fungus is an Ascomycete and can use conidia or ascospores to infect. There are three races of ''B. maydis'': Race O, Race C, and Race T; SCLB symptoms vary depending on the infectious pathogen's race. Race T is infectious to corn plants with the Texas male sterile cytoplasm (cms-T cytoplasm maize) and this vulnerability was the cause of the United States SCLB epidemic of 1969-19701 Ullstrup, A. J., ''Annual Review of Phytopathology'' 10 (1), 37 (1972). For this reason, Race T is of particular interest. While SCLB thrives in warm, damp climates, the disease can be found in many of the world's maize-growing areas. Typical management practices include breeding for host resistance, cultural controls and fungicide use. Hosts The primary host for Southern corn leaf blight is ''Zea mays'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungal Plant Pathogen
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants. Not included are ectoparasites like insects, mites, vertebrate, or other pests that affect plant health by eating plant tissues. Plant pathology also involves the study of pathogen identification, disease etiology, disease cycles, economic impact, plant disease epidemiology, plant disease resistance, how plant diseases affect humans and animals, pathosystem genetics, and management of plant diseases. Overview Control of plant diseases is crucial to the reliable production of food, and it provides significant problems in agricultural use of land, water, fuel and other inputs. Plants in both natural and cultivated population ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Disease Resistance
Plant disease resistance protects plants from pathogens in two ways: by pre-formed structures and chemicals, and by infection-induced responses of the immune system. Relative to a susceptible plant, disease resistance is the reduction of pathogen growth on or in the plant (and hence a reduction of disease), while the term disease tolerance describes plants that exhibit little disease damage despite substantial pathogen levels. Disease outcome is determined by the three-way interaction of the pathogen, the plant and the environmental conditions (an interaction known as the disease triangle). Defense-activating compounds can move cell-to-cell and systematically through the plant's vascular system. However, plants do not have circulating immune cells, so most cell types exhibit a broad suite of antimicrobial defenses. Although obvious ''qualitative'' differences in disease resistance can be observed when multiple specimens are compared (allowing classification as “resistant” or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposon
A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transposition often results in duplication of the same genetic material. Barbara McClintock's discovery of them earned her a Nobel Prize in 1983. Its importance in personalized medicine is becoming increasingly relevant, as well as gaining more attention in data analytics given the difficulty of analysis in very high dimensional spaces. Transposable elements make up a large fraction of the genome and are responsible for much of the C-value, mass of DNA in a eukaryotic cell. Although TEs are selfish genetic elements, many are important in genome function and evolution. Transposons are also very useful to researchers as a means to alter DNA inside a living organism. There are at least two classes of TEs: Class I TEs or retrotransposons generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclusive Composite Interval Mapping
In statistical genetics, inclusive composite interval mapping (ICIM) has been proposed as an approach to QTL (quantitative trait locus) mapping for populations derived from bi-parental crosses. QTL mapping is based on genetic linkage map and phenotypic data and attempts to locate individual genetic factors on chromosomes and to estimate their genetic effects. Additive and dominance QTL mapping Two genetic assumptions used in ICIM are (1) the genotypic value of an individual is the summation of effects from all genes affecting the trait of interest; and (2) linked QTL are separated by at least one blank marker interval. Under the two assumptions, they proved that additive effect of the QTL located in a marker interval can be completely absorbed by the regression coefficients of the two flanking markers, while the QTL dominance effect causes marker dominance effects, as well as additive by additive and dominance by dominance interactions between the two flanking markers. By includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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