• Korean Journal of Agricultural Science
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• v.27 no.2
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• pp.101-106
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• 2000

A total of 181 Holstein and 73 Korean cattle were used to investigate the association of bovine leukemia virus (BLV) resistance stains with major economic traits. The frequencies of BLV resistance strain with 91bp PCR products were 60.0% and 40.0% in Holsten and Korean cattle, respectively. The association of BLV resistance and susceptibility strains with 305-d milk and 305-d milk fat yields were not significant(P>0.05) in Holstein cattle. Body weights at birth, 6-mon, and 120-mon of age were not significantly associated with the BLV resistance and susceptibility strains of Holstein and Korean cattle. It could be concluded that the alleletypers of BLV resistance were not associated with major economic traits in Holstein and Korean cattle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.105-110
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• 2010

This study was conducted to analyze the relationships between resistance of brown planthopper and traits related to the lodging in rice. For the linkage analysis of traits tested in this study, a genetic linkage map was created with 162 DNA markers spanning 12 rice chromosomes based on 120 doubled haploid (DH) lines, which were derived from a cross between Samgang', a Tongil type cultivar with BPH resistance, and ‘Nagdong’, a japonica cultivar. QTLs were identified to analyze the agronomic traits including lodging by composite interval mapping. Thirteen QTLs were detected for five traits comprised of plant length (PL), 3rd internode length (3rdIL), moments (Mo), lodging index (LI), and breaking weight (BW). The relationships between the BPH resistance and agronomic traits including lodging revealed that two QTLs (qBPR7, qBPR8) were linked to traits related to lodging. Two QTLs, qBPR7 and qBPR8 on chromosome 7 (RM531-7042) and 8 (RM1148- RM544) showed associations with moments and 3rd internode length, respectively.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.236-243
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• 2009

This study was conducted to develop a japonica-type rice cultivar with brown planthopper (BPH) resistance using DNA markers. A doubled haploid (DH) population consisting of 120 pure-lines was established by anther culture of $F_1$ hybrids between 'Samgang', a Tongil type BPH resistance cultivar, and 'Nagdong', a japonica cultivar. To determine the map position of genes responsible for BPH resistance in rice, a genetic map was constructed based on 120 DH lines. A total of 162 molecular markers were classified into 12 linkage groups, covering 1,884 Kosami centimorgan (cM) with an average of 11.6 cM. Five QTLs (qBPR3, qBPR6, qBPR7, qBPR8, and qBPR12) associated with BPH resistance were identified and mapped on chromosomes 3, 6, 7, 8, and 12, respectively, using the genetic map constructed in this study. To analyze the relationship between BPH resistance and agronomic traits, a total of eight QTLs related to the agronomic traits were detected on 12 rice chromosomes. In an analysis of relationships, three QTLs (qBPR3, qBPR7, and qBPR8) showed a linkage with tested agronomic traits. A QTL (qBPR3) located on chromosome 3 (RM282-3023) was closely linked to culm length (qCL3). The QTL (qBPR8) for BPH resistance on the short arm of chromosome 8 also overlapped the region detected in culm length (qCL8).

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.166-166
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• 2021

• Horticultural Science & Technology
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• v.32 no.6
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• pp.745-752
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• 2014

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is an economically important vegetable crop as a source of the traditional food Kimchi in Korea. Although many varieties exhibiting desirable traits have been developed by the conventional selective breeding approach, breeding related to abiotic or biotic stresses, such as a particular pests or diseases, or tolerance to climatic conditions, is likely to be slow. This could be helped by an efficient method for selection from various, rapidly-evolved genetic resources on the basis of molecular markers. In particular, the Brassica genome sequencing project enables genome-wide discovery of genes or genetic variants associated with agricultural traits. We here discuss the recent progress in the field of Chinese cabbage breeding with regard to the application of molecular markers.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.384-392
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• 2023

Stomatal pore is an important physiological trait that is closely linked to photosynthesis and transpiration as carbon dioxide and water vapor move through it between the atmosphere and plants. The present study investigated stomatal traits, such as stomatal density, index and size, of herbaceous native and alien plant species living in a riparian park on the Nakdong River to understand how those traits vary and to know if successful settlement of alien plants is attributed to those traits. There was no difference in stomatal density, index and size between native and alien plants with kidney-shaped stomata, suggesting that an empty ecological niche is not an essential prerequisite for the successful settlement of alien plants. Stomatal density showed a negative correlation with leaf thickness and leaf dry weight content (LMDC), but there was no correlation with Specific leaf area (SLA). All plants with kidney-shaped stomata had amphistomatous leaves, and the density and size of dumbell-shaped stomata were lower than those of kidney-shaped stomata.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.265-273
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• 2022

Waxy corn (Zea mays L.), which contains homozygous mutant alleles for the waxy1 (wx1) gene, is widely consumed as a snack food in Asia. This study evaluated sixteen agronomic characteristics of inbred Korean waxy corn lines to aid development of high-quality waxy corn cultivars. The plant materials studied were 177 inbred waxy corn lines developed by the National Institute of Crop Science, Rural Development Administration, Republic of Korea. For the tested lines, days to tasseling and silking averaged 77.69±2.22 days (with a range of 56-97 days), and 81.12±7.56 days (66-99 days), respectively. Plant length ranged from 88 to 237 cm (averaged 164.88±22.67 cm), ear length averaged 11.75±2.52 cm (5.0-18.5 cm), and ear width averaged 2.94±0.68 cm (1.4-4.5 cm). The number of rows on each ear of corn averaged 12.22±2.22 (7-32 rows) and the kernel number averaged 24.30±4.22 (9-37 kernels) per row. The crude protein content was 12.05±1.53% (8.90-21.80%) and total starch content was 69.27±5.74% (49.5-83.9%). Principal component analysis revealed that ear width, grain length, ear length, days to tasseling, days to silking, percentage of ear setting height, and total starch are features that allow distinction between the 177 waxy inbred corn lines. Hierarchical cluster analysis identified twelve waxy inbred lines that produce tall plants and have a short silking period. These lines may improve yield among quickly growing corn varieties.

• Journal of agriculture & life science
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• v.50 no.3
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• pp.99-117
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• 2016

Data on primal cuts were collected from 1,829 steers of Hanwoo progeny testing programs, between 2010 and 2015 for the ssGWAS. SNP data were analyzed by using Illumina Bovine 50K Beadchip. The SNP data that matches with phenotype data was 674 animals. As a first step, the genomic estimated breeding value(GEBV) of the loin and rib cuts were estimated, which was used in the estimation of SNP marker effects and their variances related to the traits. Then, the estimated variance explained by each marker was expressed as a proportion to the total genetic variance. Finally, the SNP loci and their significance to any possible QTL were examined. Among the 20 best SNP loci explaining a larger proportion of SNP variance to the total genetic variance for tender loin yield, the region between 12,812,193 ~ 12,922,313bp on BTA 10 harbored a cluster of SNPs that explained about 7.32 to 7.34% of the total genetic variance. For strip loin yield, a peak for higher effects for multiple SNPs was found in BTA24, between 38,158,543 and 38,347,278bp distances, which explained about 8.36 to 8.56% of the observed variance for this trait. For loin yield had relatively smaller effects in terms of the total genetic variance. Therefore, loin yield might be affected by a few loci with moderate effects and many other loci with smaller effects across the genome.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.326-335
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• 2015

Citrus is an economically important fruit tree with the largest amount of fruit production in the world. It provides important nutrition such as vitamin C and other health-promoting compounds including its unique flavonoids for human health. However, it is classified into the most difficult crops to develop new cultivars through conventional breeding approaches due to its long juvenility and some unique reproductive biological features such as gamete sterility, nucellar embryony, and high level of heterozygosity. Due to global warming and changes in consumer trends, establishing a systematic and efficient breeding programs is highly required for sustainable production of high quality fruits and diversification of cultivars. Recently, reference genome sequences of sweet orange and clementine mandarin have been released. Based on the reference whole-genome sequences, comparative genomics, reference-guided resequencing, and genotyping-by-sequencing for various citrus cultivars and crosses could be performed for the advance of functional genomics and development of traits-related molecular markers. In addition, a full understanding of gene function and gene co-expression networks can be provided through combined analysis of various transcriptome data. Analytic information on whole-genome and transcriptome will provide massive data on polymorphic molecular markers such as SNP, INDEL, and SSR, suggesting that it is possible to construct integrated maps and high-density genetic maps as well as physical maps. In the near future, integrated maps will be useful for map-based precise cloning of genes that are specific to citrus with major agronomic traits to facilitate rapid and efficient marker-assisted selection.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.2
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• pp.111-122
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• 2024

This study was conducted to evaluate agronomic traits and classify phylogenetic characteristics of Korean wheat landraces (KWLs) collected in Gyeongnam province. We used the squash method for chromosome observation, image analysis to examine seed characteristics, and genotyping using commercial single-nucleotide polymorphism chips to construct a phylogenetic tree. All KWLs contained 42 chromosomes and two pairs of microsatellites as observed in Keumgang, a Korean wheat cultivar. All KWLs showed smaller seed traits compared with those of Keumgang, although KWL-3 had a larger embryo length than that of Keumgang. Among agronomic traits compared with those of Keumgang, all KWLs had a late heading date and ripening period except for KWL-3, which showed the smallest culm and spike length. KWL-1 had the lowest tiller, highest floret, and grain number. All KWLs showed a lower thousand grain weight than that of Keumgang because of their smaller seeds. In the variation of variety and area, the heading date, ripening period, tiller number, and floret number were affected by the cultivation area, whereas the culm length, spike length, and 1000 grain weight were affected by the variety. Correlation distribution analysis showed differences in agronomic traits according to the cultivation area, and the heading date was positively correlated with the culm length and floret number in three cultivation areas. Principal component analysis explained that the heading date had a positive relationship with the ripening period and floret number and a negative relationship with the tiller number. Principal component analysis also revealed that all KWLs had a lower thousand grain weight than that of Keumgang. Phylogenetic tree showed that KWL-1 was near KWL-3, while KWL-2 was near KWL-4. All KWLs were genetically near the Korean wheat cultivars milsung and saeol, whereas they were genetically far from the Korean wheat cultivars goso and olgrue.