• The Plant Pathology Journal
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• v.17 no.1
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• pp.1-8
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• 2001

The technique of plant transformation has started to show off its great power in the area of plant breeding by commercially successful introduction of transgenic varieties such as herbicide tolerant soybean and insect resistant corn in USA with an unimaginable speed. However, in contrast with the great success in the commercialization of herbicide tolerance and insect resistance, the transformation works on disease resistance has not yet reached the stage of full commercialization. This review surveys the current status of molecular breeding for plant disease resistance and their limits and problems. Some novel ideas and approaches in molecular breeding for disease resistance are introduced.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.143-143
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• 2017

Wheat is one of the most important crops in production and consumption. Despite increasing of importance, the self-sufficiency of wheat is less than 2% in Korea. To improve yield potential and broaden the genetic pool of common wheat in Korea, introduction of alien germplasms into the Korean wheat breeding program is suggested. For effective utilization of the germplasm, we introduced total 1,195 germplasms from the world, which were provided by National Plant Germplasm System (NPGS, USDA) and evaluated the yield, field performances and agronomic traits for 8 years. Among 55 countries, germplasms from Canada, Ethiopia, Mexico and United States accounts for 78%, especially germplasms collected from United States accounts for 50%. Yield comparison of germplasms and collected region analysis indicate that the high yielding germplasms are collected from countries or states of particular range of latitude. The combination analysis of the yield and agronomic traits and the geographical information of collected region will be utilized for improving Korean wheat breeding programs.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.357-369
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• 2010

Cymbidium is horticulturally important and has been one of the most commercially successful orchid plants as well as cut flowers around the world including Korea. Up to now, a huge number of elite Cymbidium cultivars have been released on the commercial market via cross-hybridization, mutation and polyploidization breeding techniques. To investigate on breeding system in Cymbidium, we inquired the brief history and techniques of breeding and the current status on Cymbidium breeding in Korea. Also, the general propagation process of elite Cymbidium lines via tissue culture should be presented. However, the slow process of conventional breeding and the lack of useful genes in Cymbidium species delays the introduction of new cultivars to the commercial market. To solve these limitations, efficient regeneration and genetic transformation systems should be established in the improvement of Cymbidium breeding program. During the last several decades, some progress has been made in tissue culture and genetic transformation in Cymbidium species. We review the recent status of tissue culture and genetic transformation systems in Cymbidium plants.

• Journal of Sericultural and Entomological Science
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• v.37 no.1
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• pp.10-15
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• 1995

Genetic characterization of Sri Lankan silkworm bivoltine population has not been at-tempted so far, since its sporadic introduction of bivoltine strains into the island, starting from the 1950's. Genetic structure of Sri Lankan population of mulberry silkworm Bombyx mori was investigated through estimation of general (GCA) and specific combining ability(SCA) and heritability(${h^2}_B$), on the economic quantitative characters from leading 8 inbreds and their 28 F1's in a half diallel cross, in an attempt to utilize the estimates in determination of future breeding methods and to predict the breeding value over the phenotypic value. It was found that the breeding population of the bivoltine silkworm in Sri Lanka has still maintained considerable amounts of additive gene action as well as nonadditive. For some time in the future, both breeding strategies of "selection without inbreeding" and also "inbreeding followed by crossing" should therefore be effective in genetic improvement of economic characters investigated. In addition, superior combiners in general and in specific F1′s were identified for each of 6 economic characters, to be immediately utilized in selection and also in cross breeding programs in Sri Lanka.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.13-13
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• 2017

By the progress of genome sequencing, infrastructures for marker-assisted breeding (MAB) of rice came to be established. Fine mapping and gene isolation have been conducted using the breeding materials derived from natural variations and artificial mutants. Such genetic analysis by the genome-wide dense markers provided us the knowledge about the many genes controlling important traits. We identified several genes or quantitative trait loci (QTL) for heading date, blast resistance, eating quality, high-temperature stress tolerance, and so on. NILs of each gene controlling heading date contribute to elongate the rice harvest period. Determination of precise gene location of blast resistance gene pi21, allowed us to overcome linkage drag, co-introduction of undesirable eating quality. We could also breed the first practical rice cultivar in Japan with a brown planthopper resistance gene bph11 in the genetic back-ground of an elite cultivar. Discovery of major and minor QTLs for good eating quality allowed us to fine-tune of eating quality according to the rice planting area or usage of rice grain. Many rice cultivars have bred efficiently by MAB for several traits, or by marker-assisted backcross breeding through chromosome segment substitution lines (CSSLs) using genetically diverse accessions. We are also systematically supporting the crop breeding of other sectors by MAB or by providing resources such as CSSLs. It is possible to pyramid many genes for important traits by using MAB, but is still difficult to improve the yielding ability. We are performing a Genomic Selection (GS) for improvement of rice biomass and grain yield. We are also trying to apply the genome editing technology for high yield rice breeding.

• Development and Reproduction
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• v.16 no.4
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• pp.309-314
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• 2012

This study was conducted to analyze the difference of body types within and between wild and farmed populations of olive flounder Paralichthys olivaceus using measured records of morphological traits. The results showed that surveyed traits and standard deviation were $1,355{\pm}742g$ of body weight, $48.01{\pm}7.79cm$ of total length, and $40.96{\pm}6.80cm$ of body length. Also body height, body shape index and condition factor were $17.19{\pm}3.43cm$, $9.99{\pm}0.74$ and $11.16{\pm}1.54$, respectively. As result of least squares mean and standard error for each trait assumed in this study, those of farmed population showed significantly higher than those of wild population in all traits, exclusively in total length and body length (p<0.01). Particularly, the values of the body height and the body weight of the farmed population were higher than those of the wild population in the same total length. And the phenotypic correlation coefficients of the body weight, the total length, the body length and the body height showed strong positive correlation in all populations. These result suggested that morphological differences exist in farmed and wild flounder. Therefore, introduction of wild flounder is essential for the future production to improve the body type of farmed flounder, and parental fish should be chosen by considering selection of commercially important traits in the production process.

• Fire Science and Engineering
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• v.34 no.2
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• pp.54-63
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• 2020

Although fires caused by heat generation due to Cu₂O breeding in wire connections are well-known among fire investigators, there are few papers on the analysis and introduction of fire cases by heat generation due to Cu₂O breeding. This study analyzed fire statistics caused by heat generation in electrical connections and the phenomena and features of heat generation due to Cu₂O breeding. Then, a fire which occurred in the wire connection in a university lab by heat generation due to Cu₂O breeding was analyzed in more detail. This fire case could reach a conclusion that heat generation due to Cu₂O breeding caused a fire in the wire connection through the fire pattern investigation of fire origin, the visual investigation of wire connection, 3D CT, power-on-test, and stereoscopic microscopy, SEM and EDS analysis.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.23-32
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• 2002

The introduction of hybrid and exploitation of heterosis has played a vital role in Indian sericulture industry, which clearly depicts a quantum jump in silk production during the last four decades. Since, the introduction of heterosis, progress in silkworm breeding has depended on success or failure in identifying better combiners. Systematic procedures developed have enabled the breeders to identify the best combiners by combining ability test, line ${\TIMES}$ tester analysis or $D^2$ analysis for maximum expression of heterosis. The level of heterosis expressed in the crossbreed population is determined by the interaction between genotype and prevailing environmental factors. Except some of the pre and post cocoon parameters, heterosis is invariably higher in single crosses compared to three-way and double crosses. However, during hot and humid season, when rearing of F1 bivoltine hybrid is unsuccessful at field level and indigenous races results in very low and poor quality yield, three-way and double crosses can play an important role as an intermediary technology. The objective of this article is to review briefly the concept and causes of heterosis, utilization of different forms of heterosis in silk production and its significance in silkworm, Bombyx mori breeding.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.317-323
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• 2018

The demand for crop production is increasingly becoming steeper due to the rapid population growth. As a result, breeding cycles should be faster than ever before. However, the current breeding methods cannot meet this requirement because traditional phenotyping methods lag far behind even though genotyping methods have been drastically developed with the advent of next-generation sequencing technology over a short period of time. Consequently, phenotyping has become a bottleneck in large-scale genomics-based plant breeding studies. Recently, however, phenomics, a new discipline involving the characterization of a full set of phenotypes in a given species, has emerged as an alternative technology to come up with exponentially increasing genomic data in plant breeding programs. There are many advantages for using new technologies in phenomics. Yet, the necessity of diverse man power and huge funding for cutting-edge equipment prevent many researchers who are interested in this area from adopting this new technique in their research programs. Currently, only a limited number of groups mostly in developed countries have initiated phenomic studies using high throughput methods. In this short article, we describe the strategies to compete with those advanced groups using limited resources in developing countries, followed by a brief introduction of high throughput phenotyping.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.51-57
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• 1980

Thirty-one Tobacco Introduction (Nicotiana tabacum L.) lines from Agricultural Research Service, United States Department of Agriculture, were assayed for their resistance to tobacco mosaic virus. The T.1.'s were grouped into two classes according to symptoms - symptomless and local lesion. Tobacco Introductions in the symptomless group yielded better than the local lesion group but the leaf quality was lower. The chemical composition of cured leaves was similar in both groups. Considering various agronomic characters, T.I. 1504 in the local lesion group is recommended as a new source for the breeding of TMV resistance.