• International Journal of Industrial Entomology and Biomaterials
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• v.11 no.2
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• pp.119-124
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• 2005

To determine the level of heterosis, higher cocoon shell weight multivoltine congenic lines (Con. L) and bivoltine syngenic lines (Syn. L) of silkworm were used for crosses. First filial generations $(F_1s)$ expressed heterobeltiotic genetic interaction at significant magnitude (p < 0.01) for single cocoon shell weight (SCSW). The other linked characters viz., single cocoon weight (SCW) and yield by weight per 10, 000 larvae were also significantly higher (p < 0.01) than the better parental lines. All the hybrids showed significant improvement for these aforesaid characters over standard heterosis (Standard check). The reeling parameters viz., filament length, raw silk, neatness, cohesionstrokes etc, also showed improvement among the hybrids than check in congenial environment. Overall results suggested that the cross between congenic and syngenic lines provide better heterosis with good quality silk than conventional hybrids and may be used for commercial exploitation.

• 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.

• Plant Breeding and Biotechnology
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• v.5 no.2
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• pp.134-142
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• 2017

Resource plants are important and have strong potential for a variety of utilities as crops or pharmaceutical materials. However, most resource plants remain wild and thus their utility for breeding and biotechnology is limited. Molecular markers are useful to initiate genetic study and molecular breeding for these understudied resource plants. We collected various wild collections of Peucedanum japonicum which is indigenous resource plants utilized as oriental medicine and leafy vegetables in Korea. In this study, we produced two independent whole genome sequences (WGSs) from two collections and identified large scale polymorphic simple sequence repeat (pSSR) based on our pipeline to develop SSR markers based on comparison of two WGSs. We identified a total of 452 candidate pSSR contigs. To confirm the accuracy and utility of pSSR, we designed ten SSR primer pairs and successfully applied those to seven collections of P. japonicum. The WGS and pSSR candidates identified in this study will be useful resource for genetic research and breeding purpose for the valuable resource plant, P. japonicum.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.8
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• pp.1074-1080
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• 2017

Objective: The growth, carcass and retail cut yield records on 1,428 Hanwoo steers obtained through progeny testing were analyzed in this study, and their heritability and genetic relationships among the traits were estimated using animal models. Methods: Two different models were compared in this study. Each model was fitted for different fixed class effects, date of slaughter for carcass traits and batch of progeny test live measurement traits, and a choice of covariates (carcass weight in Model 1 or backfat thickness in Model 2) for carcass traits. Results: The differences in body composition among individuals were deemed being unaffected by their age at slaughter, except for carcass weight and backfat thickness. Heritability estimates of body size measurements were 0.21 to 0.36. Heritability estimates of retail cut percentage were high (0.56 from Model 1 and 0.47 from Model 2). And the heritability estimates for loin muscle percentage were 0.36 from Model 1 and 0.42 from Model 2, which were high enough to consider direct selection on carcass cutability traits as effective. The genetic correlations between body size measurements and retail cut ratio (RCR) were close to zero. But, some negative genetic correlations were found with chest girths measured at yearling (Model 1) or at 24 months of age or with chest widths. Loin muscle ratio (LMR) was genetically negatively correlated with body weights or body size measurements, in general in Model 1. These relationships were low close to zero but positive in Model 2. Phenotypic correlation between cutability traits (RCR, LMR) and live body size measurements were moderate and negative in Model 1 while those in Model 2 were all close to zero. Conclusion: Therefore, the body weights or linear body measurements at an earlier age may not be the most desirable selection traits for exploitation of correlated responses to improve loin muscle or lean meat yield.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.239-245
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• 1994

The broad sense heritability of height of clonal means was estimated from 18 clones out of 25 clones growing at four different sites, and it showed considerably high heritability of $H^2_{CM}=0.883$. Therefore if we select the best one clone(5% selection), the genetic gain of 35.3% which is equal to 1.02m in height is expected to attain. If we select the best two clones(10% selection), the genetic gain will be 25.6% which is equal to 0.74m in height. Because the trees are only 4-year-old, it is expected to show higher genetic gain than the current gain when the trees reach to the age of final selection.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.11b
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• pp.25-32
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• 2001

Potatoes have been recognized for a long time as one of the major food crops as well as horticultural crops. Potato production as a table food has been decreased in developed countries, while it has been steadily increased in the third world countries for it importance as food source. It is a new trend to look for the food, not only as a feeding crop but also healthy food. It is also time for the potato producers to look for the potato having high economic value as found in medicinal plants. There are great diversities in potato species, indicating that valuable compounds can be found in different amounts, depending on potato species. We screened the cultivars, breeding clones, and germplasms based on the vitamin C, Vitamin E, antioxidant compounds, diverse sugar types, important amino acids, and other valuable compounds. We could select the breeding clones KC003, 98Wl17, 99j717, and Vally 8 (A group) due to their high levels of antioxidant compounds, and it can be said that most of the red and purple colored potato clones belong to the A group. In the contents of essential amino acids, ‘Taebook Valley’,‘Summer Valley’ and other breeding clones were found to be high in amount. We also made crosses between breeding clones with high biological function and low agronomic traits and low biological function with high quality in agronomic characteristics . The patterns of genetic trends of these offsprings in comparison with their parents will be reported as well. And the potential of using potato as antibody production of anti-cancer will be discussed.

• Korean Journal of Plant Resources
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• v.33 no.6
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• pp.615-623
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• 2020

Brassica rapa is one of the most valuable vegetable crops worldwide. Cultivated varieties of B. rapa exhibit diverse developmental and morphological appearances, which includes important vegetables, oilseeds, and fodder crops. In this study, various phenotypes of recombinant inbred lines (RILs) of B. rapa were investigated, including their responses to five different pathogenic Botrytis cinerea isolates, responses to aphid and thrips during flowering stages, days to flowering, and plant heights. Responses of 113 RILs to five different B. cinerea isolates showed variations, suggesting that genetic factors controlling resistance or tolerance against each isolate were dependent on isolate/genotype pairs. Correlation analysis was performed to understand the nature of genetic factors and the relationship among these phenotypes. Although high levels of correlation were not detected between phenotypes assessed in this study, statistically significant correlation was detected for several combinations. Significant positive correlations were found for different B. cinerea isolates, supporting that certain levels of commonality could exist in genetic components controlling resistance against different B. cinerea isolates. Based on correlation analysis using numbers of insects counted on plants, it was speculated that genetic factors responsible for aphid tolerance or repellence might be also involved in the response against thrips. Relationship between vegetative growth and tolerance against B. cinereal or insects is rather more complicated. However, it was observed that shorter plants appeared to have a certain level of tolerance or repellence against both aphids and thrips. Data presented in this study could be used to assist further genetic studies and breeding efforts to obtain Botritis and insect resistance for B. rapa.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.399-404
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• 2011

Genetic diversity among 28 Cymbidium varieties was evaluated by using a sequence-related amplified polymorphism (SRAP) marker system. The SRAP marker which was based on the open reading frames (ORFs) regions was developed primarily for Brassica species, but has been applied to various crops. A total of 30 SRAP primer combinations were initially screened. Twenty-eight SRAP primer combinations showed high polymorphism among the 28 Cymbidium varieties, which were consisted of breeding varieties and their parents in National Institute of Horticultural & Herbal Science (NIHHS). The amplified DNA fragments were separated by denaturing acrylamide gels and detected silver staining method. One hundred ninety six polymorphic bands (7 per primer) were generated and ranged from 0.3 to 1.0 kb in size. Polymorphic fragments were scored for calculating simple matching coefficient of genetic similarity and cluster analysis with multi-variate statistical package (MVSP) 3.1. The mean genetic similarity coefficient value was 0.588. The results showed that the correlation between $F_1$ varieties and their parents was high. These studied SRAP markers will be useful tools for genotype identification, germplasm conservation, genetic relationships in Cymbidium.

• Mycobiology
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• v.49 no.4
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• pp.406-420
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• 2021

Gloeostereum incarnatum has edible and medicinal value and was first cultivated and domesticated in China. We sequenced the G. incarnatum monokaryotic strain GiC-126 on an Illumina HiSeq X Ten system and obtained a 34.52-Mb genome assembly sequence that encoded 16,895 predicted genes. We combined the GiC-126 genome with the published genome of G. incarnatum strain CCMJ2665 to construct a genetic linkage map (GiC-126 genome) that had 10 linkage groups (LGs), and the 15 assembly sequences of CCMJ2665 were integrated into 8 LGs. We identified 1912 simple sequence repeat (SSR) loci and detected 700 genes containing 768 SSRs in the genome; 65 and 100 of them were annotated with gene ontology (GO) terms and KEGG pathways, respectively. Carbohydrate-active enzymes (CAZymes) were identified in 20 fungal genomes and annotated; among them, 144 CAZymes were annotated in the GiC-126 genome. The A mating-type locus (MAT-A) of G. incarnatum was located on scaffold885 at 38.9 cM of LG1 and was flanked by two homeodomain (HD1) genes, mip and beta-fg. Fourteen segregation distortion markers were detected in the genetic linkage map, all of which were skewed toward the parent GiC-126. They formed three segregation distortion regions (SDR1-SDR3), and 22 predictive genes were found in scaffold1920 where three segregation distortion markers were located in SDR1. In this study, we corrected and updated the genomic information of G. incarnatum. Our results will provide a theoretical basis for fine gene mapping, functional gene cloning, and genetic breeding the follow-up of G. incarnatum.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.04a
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• pp.110-110
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• 2022

Rice is the world's most important food crop and a major source of nutrition for about two thirds of populations. Northern Vietnam is one of the most important centers of genetic diversity for cultivated rice. In this study, we determined the genetic diversity and population structure of 79 rice landraces collected from northern Vietnam and 19 rice accessions collected from different countries. In total, 98 rice accessions could be differentiated into japonica and indica with moderate genetic diversity and a polymorphism information content of 0.382. We also detected subspecies-specific markers to classify rice (Oryza sativa L.) into indica and japonica. Additionally, we detected five marker-trait associations and rare alleles that can be applied in future breeding programs. Most interestingly, analysis of molecular variance (AMOVA) found genetic differentiation was related to geographical regions with an overall PhiPT (analog of fixation index FST) value of 0.130. More emphasis was given to provide signatures and infer explanations about the role of geographical isolation and environmental heterogeneity in genetic differentiation among regions in landraces from northern Vietnam. Our results suggest that rice landraces in northern Vietnam have a dynamic genetic system that can create different levels of genetic differentiation among regions, but also maintain a balanced genetic diversity between regions.