• Title/Summary/Keyword: genetic mapping

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Challenges for QTL Analysis in Crops

  • Long, Yan;Zhang, Chunyu;Meng, Jinling
    • Journal of Crop Science and Biotechnology
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    • v.11 no.1
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    • pp.7-12
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    • 2008
  • Quantitative trait loci, a genetic concept for explaining the inheritance of non-Mendelian traits in 1940s, have been realized as particular fragments of chromosome even unique genes in most crops in 21st century. However, only very a small portion of QTL has been screened out by geneticists comparing to a great number of genes underneath the quantitative traits. These identified QTL even have been seldom used into breeding program because crop breeders may not find the QTL in their breeding populations in their field station. Several key points will be proposed to meet the challenges of QTL analysis today: a fine mapping population and the related reference genetic map, QTL evaluation in multiple environments, recognizing real QTL with small genetic effect, map integration.

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QTL Mapping of Resistance to Gray Leaf Spot in Ryegrass: Consistency of QTL between Two Mapping Populations

  • Curley, J.;Chakraborty, N.;Chang, S.;Jung, G.
    • Asian Journal of Turfgrass Science
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    • v.22 no.1
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    • pp.85-100
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    • 2008
  • Gray leaf spot (GLS) is a serious fungal disease caused by Pyricularia oryzae Cavara, recently reported on the important turf and forage species, perennial ryegrass (Lolium perenneL.). This fungus also causes rice blast, which is usually controlled by host resistance, but durability of resistance is a problem. Few instances of GLS resistance have been reported in perennial ryegrass. However, two major QTL for GLS resistance have been detected on linkage groups 3 and 6 in an Italian x perennial ryegrass mapping population. To confirm that those QTL are still detectable in the next generation and can function in a different genetic background, a resistant segregant from this population has been crossed with an unrelated susceptible perennial clone, to form a new mapping population segregating for GLS resistance. QTL analysis has been performed in the new population, using two different ryegrass field isolates and RAPD, RFLP, and SSR marker-based linkage maps for each parent. Results indicate the previously identified QTL on linkage group 3 is still significant in the new population, with LOD and percent of phenotypic variance explained ranging from 2.0 to 3.5 and 5% to 10%, respectively. Also two QTL were detected in the susceptible parent, with similar LOD and phenotypic variance explained. Although the linkage group 6 QTL was not detected, the major QTL on linkage group 3 appears to beconfirmed. These results will add to our understanding of the genetic architecture of GLS resistance in ryegrass, which will facilitate its use in perennial ryegrass breeding programs.

Genetic Improvement of Maize by Marker-Assisted Breeding (분자마커를 활용한 옥수수 육종)

  • Kim, Jae Yoon;Moon, Jun-Cheol;Baek, Seong-Bum;Kwon, Young-Up;Song, Kitae;Lee, Byung-Moo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.59 no.2
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    • pp.109-127
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    • 2014
  • Maize is one of the most important food and feed crops in the world including Southeast Asia. In spite of numberous efforts with conventional breeding, the maize productions remain low and the loss of yields by drought and downy mildew are still severe in Asia. Genetic improvement of maize has been performed with molecular marker and genetic engineering. Because maize is one of the most widely studied crop for its own genome and has tremendous diversity and variant, maize is considered as a forefront crop in development and estimation of molecular markers for agricultural useful trait in genetics and breeding. Using QTL (Quantitative Trait Loci) and MAS (Marker Assisted Breeding), molecular breeders are able to accelerate the development of drought tolerance or downy mildew resistance maize genotype. The present paper overviews QTL/MAS approaches towards improvement of maize production against drought and downy mildew. We also discuss here the trends and importance of molecular marker and mapping population in maize breeding.

A Study on the Optimal Design Fuzzy Type Stabilizing Controller using Genetic Algorithm (유전 알고리즘을 이용한 퍼지형 안전화 제어기의 최적 설계에 관한 연구)

  • Lee, Heung-Jae;Lim, Chan-Ho;Yoon, Byong-Gyu;Lim, Hwa-Young;Song, Ja-Youn
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.48 no.11
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    • pp.1382-1387
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    • 1999
  • This paper presents an optimal fuzzy power system stabilizer to damp out low frequency oscillation. So far fuzzy controllers have been applied to power system stabilizing controllers due to its excellent properties on the nonlinear systems. But the design process of fuzzy logic power system stabilizer requires empirical and heuristic knowledge of human experts as well as many trial-and-errors in general. This paper presents and optimal design method of the fuzzy logic stabilizer using the genetic algorithm. Non-symmetric membership functions are optimally tuned over an evaluation function. The present inputs of fuzzy stabilizer are torque angle error and the change of torque angle error without loss of generality. The coding method used in this paper is concatenated binary mapping. Each linguistic fuzzy variable, defined as the peak of a membership function, is assigned by the mapping from a minimum value to a maximum value using eight bits. The tournament selection and the elitism are used to keep the worthy individuals in the next generation. The proposed system is applied to the one-machine infinite-bus model of a power system, and the results showed a promising possibility.

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Strategic Use of QTL Mapping to Improve the Palatability of Rice

  • Yoon-Hee Jang;Jae-Ryoung Park;Eun-Gyeong Kim;Kyung-Min Kim
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.286-286
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    • 2022
  • The properties of starch play an important role in determining the palatability of rice. In addition, the gelatinization temperature (GT) of rice starch is an important factor in determining the quality of rice because it is related to the cooking time and texture of rice. For the development of high-quality rice, it is important to understand the genetic basis of palatability-related traits, and QTL analysis is an effective method to explain the genetic basis of variation in complex traits. QTL mapping related to alkali digestion value (ADV) of brown and milled rice was performed using the 120 Cheongcheong/Nagdong double haploid (CNDH) line. As a result, 12 QTLs related to ADV were detected, and 20 candidate genes were selected from the RM588-RM1163 region of chromosome 6 through screening by gene function analysis. The comparison of the relative expression level of candidate genes showed that OsSS1q6 is highly expressed in CNDH lines with high ADV in both brown rice and milled rice. In addition, OsSS1q6 has high homology with starch synthase 1 protein, and interact with various starch biosynthesis-related proteins, such as GBSSII, SBE, and APL. Therefore, we suggest that OsSS1q6 identified through QTL mapping could be one of the various genes involved in the GT of rice by regulating starch biosynthesis. This study can be used as basic data for breeding high-quality rice and provides a new genetic resource that can increase the palatability of rice.

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Genetic Architecture of Transcription and Chromatin Regulation

  • Kim, Kwoneel;Bang, Hyoeun;Lee, Kibaick;Choi, Jung Kyoon
    • Genomics & Informatics
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    • v.13 no.2
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    • pp.40-44
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    • 2015
  • DNA microarray and next-generation sequencing provide data that can be used for the genetic analysis of multiple quantitative traits such as gene expression levels, transcription factor binding profiles, and epigenetic signatures. In particular, chromatin opening is tightly coupled with gene transcription. To understand how these two processes are genetically regulated and associated with each other, we examined the changes of chromatin accessibility and gene expression in response to genetic variation by means of quantitative trait loci mapping. Regulatory patterns commonly observed in yeast and human across different technical platforms and experimental designs suggest a higher genetic complexity of transcription regulation in contrast to a more robust genetic architecture of chromatin regulation.

Characterization of microsatellite markers covering chromosome 1 in the Korean and Japanese populations (한국인과 일본인에서 1번 염색체에 부착되는 microsatellite marker의 특징)

  • Lee, You-Jin;Park, Soo-Byung
    • The korean journal of orthodontics
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    • v.34 no.6 s.107
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    • pp.537-543
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    • 2004
  • Microsatellit markers are considered to be very promising genetic markers for genetic linkage analysis. The majority of the markers are as informative as in Caucasians but there are significant ethnic differences in the genetic variations. In order to investigate the genetic variations in the Korean and Japanese populations and their ethnic differences, 51 microsatellite marker loci spanning the whole human chromosome 1 were arranged from a commercially available set (ABI PRISM Linkage Mapping Set-HD5, Applied Biosystems, Foster City, CA, USA), and then determined the allelic frequencies and heterozygosities for these marker loci in the 90 unrelated Korean subjects and 90 unrelated Japanese subjects. Of all 51 markers tested, significant differences were observed when microsatellite allele frequency pattern of Korean was compared with those of Caucasian, while this pattern was highly similar between Korean and Japanese populations. Our data indicate that an extensive verification of public microsatellite markers in a particular population study should be undertaken prior to their linkage studies. Moreover, this information should facilitate genetic linkage studies of various hereditary diseases, especially in the Koreans and Japanese.

Path-planning using Modified Genetic Algorithm and SLAM based on Feature Map for Autonomous Vehicle (자율주행 장치를 위한 수정된 유전자 알고리즘을 이용한 경로계획과 특징 맵 기반 SLAM)

  • Kim, Jung-Min;Heo, Jung-Min;Jung, Sung-Young;Kim, Sung-Shin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.3
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    • pp.381-387
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    • 2009
  • This paper is presented simultaneous localization and mapping (SLAM) based on feature map and path-planning using modified genetic algorithm for efficient driving of autonomous vehicle. The biggest problem for autonomous vehicle from now is environment adaptation. There are two cases that its new location is recognized in the new environment and is identified under unknown or new location in the map related kid-napping problem. In this paper, SLAM based on feature map using ultrasonic sensor is proposed to solved the environment adaptation problem in autonomous driving. And a modified genetic algorithm employed to optimize path-planning. We designed and built an autonomous vehicle. The proposed algorithm is applied the autonomous vehicle to show the performance. Experimental result, we verified that fast optimized path-planning and efficient SLAM is possible.

Molecular Application to Psychiatry (분자생물학의 정신과적 적용)

  • Lee, Min-Soo
    • Korean Journal of Biological Psychiatry
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    • v.1 no.1
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    • pp.60-66
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    • 1994
  • Advances in molecular biology have renewed hope for the discovery of disease relevant gene. The basic strategy is gene mapping and likely to have on important role in psychiatric research and practice. Recent linkage studies of chromosomal loci to psychiatric diseases shed light on the potential for new genetics in psychiatric science. This article reviews molecular application to psychiatrymethodological issues in genetic linkage, study of gene expression by analysis of mRNA, and current linkage studies in psychiatric diseases.

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MULTI-ITEM SHELF-SPACE ALLOCATION OF BREAKABLE ITEMS VIA GENETIC ALGORITHM

  • MAITI MANAS KUMAR;MAITI MANORANJAN
    • Journal of applied mathematics & informatics
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    • v.20 no.1_2
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    • pp.327-343
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    • 2006
  • A general methodology is suggested to solve shelf-space allocation problem of retailers. A multi-item inventory model of breakable items is developed, where items are either complementary or substitute. Demands of the items depend on the amount of stock on the showroom and unit price of the respective items. Also demand of one item decreases (increases) due to the presence of others in case of substitute (complementary) product. For such a model, a Contractive Mapping Genetic Algorithm (CMGA) has been developed and implemented to find the values of different decision variables. These are evaluated to have maximum possible profit out of the proposed system. The system has been illustrated numerically and results for some particular cases are derived. The results are compared with some other heuristic approaches- Simulated Annealing (SA), simple Genetic Algorithm (GA) and Greedy Search Approach (GSA) developed for the present model.