In this study, composition and agronomic traits, including yield-related traits, were investigated and compared among 35 Korean landrace germplasm for two years (2019 and 2020). The contents of 12 isoflavones were measured using high-performance liquid chromatography, and agronomic trait data were collected according to the Rural Development Administration criteria. Comparing isoflavone composition between the two years, all isoflavones, except glycitein, were generally higher in 2019. The values of yield-related and major agronomic traits decreased in most accessions in 2020. ANOVA showed highly significant differences (p<0.001) in genotypes, years, and genotype-by-year interaction for all isoflavones, the number of pods per plant, and 100-seed weight. The number of seeds per pod, days to flowering, and days to maturity also showed significant differences among genotypes, as well as between the two years. Correlation analysis revealed that daidzin and genistin were positively correlated with their malonylated form. Malonyl daidzin was also positively correlated with malonyl genistin levels. The accessions with the least variation in the total isoflavone content were IT 153844 (907.5 µg/g, 898.6 µg/g) and IT 252252 (663.2 µg/g, 636.4 µg/g). Some of the evaluated landraces will be a promising genetic source for developing soybean varieties with high levels of environmental stability in isoflavone content and agronomic traits.

Interspecific hybridization is a valuable approach to generate genetic variation and to introgress desirable genes. The
objective
of the current study was to estimate the heritability and correlation coefficient of several fruit traits for three years (from 2016 to 2018) using a set of 178 interspecific F₁ populations developed from a cross between ‘Manpungbae’ (Pyrus pyrifolia) and ‘Oharabeni’ (P. pyrifolia×P. communis). For ‘Manpungbae’, the average values of fruit weight, length, diameter, fruit shape index, and soluble sugar content for the three years were 967.8 g, 109.0 mm, 125.7 mm, 0.87, and 13.4 °Brix, respectively. The average values for ‘Oharabeni’ were 268.2 g, 75.2 mm, 81.4 mm, 0.93, and 9.9 °Brix, respectively. The average values and heritability for three years in F₁ progenies were 222.0 g and 85.55%, 67.3 mm and 84.14%, 75.4 mm and 81.18%, 0.89 and 79.33%, and 10.7 °Brix and 77.75%, respectively. Among the five fruit traits we surveyed, the Pearson’s correlation coefficients between three traits (weight, length, and diameter) were highly significantly positive (over 0.8) for the three years.

Barley is an economically important cereal crop grown under diverse environmental conditions and ranked fourth in terms of production volume. Barley is a diploid self-fertilizing plant with seven chromosomes, and has a 5.1 Gbp genome with more than 80% repeat sequences. Whole genome re-sequencing (WGR) has provided substantial information on sequence variation distributed on all chromosomes, such as single nucleotide polymorphisms, insertions, and deletions, which are used in the development of DNA markers. In this study, we performed WGR to detect sequence variations among six Korean malting varieties. An average of 92,552 insertions and deletions (InDels) were detected in these varieties in comparison to the high-quality reference genome sequences. The InDel density of the six Korean malting varieties ranged from 17 to 19 InDel/1Mbp with an average of 18 InDel/1Mbp. No InDel could be detected in 193 regions in all chromosomes except chr. unassigned. One interval with high-density InDel, more than 150 InDel/1Mbp, was located on the 1H, 3H, 6H, and 7H chromosomes. A total of 145 InDel markers were developed using 225 large-InDel markers, longer than 50 bp. Seventeen large-InDel makers showed polymorphisms among 31 malting barley varieties. These 31 malting barley varieties were divided into four groups based on phylogenetic analysis. These results presented a development method of agarose-resolvable large-InDel markers using WGR. Seventeen polymorphic large-InDel markers were used to conserve and identify barley germplasms. This vast information on sequence variation in six Korean malting barleys could be used for the development of DNA markers and marker-assisted selection.

To better understand the morphological variation in the 189 accessions of cultivated var. frutescens of Perilla crop preserved at the RDA-Genebank in South Korea, morphological characteristics were investigated using seven traits related to leaf quality. In the principal component analysis (PCA), the first and second principal components accounted for 28.9% and 19.7% of the total variance, respectively. In the first component, leaf color (QL1) and stem color (QL3) contributed positively, whereas the flowering period (QL5) and degree of pubescence (QL6) contributed in a negative manner. In the second component, QL5 and QL6 contributed positively, whereas the fragrance of plants (QL7) contributed negatively. The results of PCA showed that the 189 Perilla accessions were clearly divided into three groups based on the 1st axis (X-axis), except for some accessions. However, the Perilla accessions collected in South Korea and abroad did not show a clear geographical distribution between the collection areas. Correlation analysis among the seven traits of 189 Perilla accessions showed a positive correlation coefficient for the combination of QL1 and QL3, and QL5 and QL6, and a negative correlation for the combination of color of the reverse side of the leaf and QL6, and QL5 and QL7. Therefore, the results of this study will provide useful information for the selection of useful resources for the development of leafy vegetable varieties of the Perilla crop and the preservation and management of genetic resources of the Perilla crop preserved at the RDA-Genebank in South Korea.

In this study, 14 agricultural and phenotypic traits were used to analyze morphological variations among 10 near-isogenic lines (NILs) of colored waxy maize and 2 parental lines (HW3 and HW9) of the hybrid cultivar “Mibaek 2.” The results of principal component analysis indicated that on the first principal component axis, seed coat color, R value, V value, days of tasseling, L* value, and days of silking greatly contributed to the positive direction, whereas anthesis–silking interval and leaf width greatly contributed to the negative direction. On the second principal component axis, kernel row number and tassel color contributed to the positive direction, whereas setted ear length, ear length, and 100-kernel weight contributed to the negative direction. Thus, the morphological characteristics that greatly contributed to the first and second principal components might be useful for discrimination among the 10 NILs and 2 parental lines of “Mibaek 2.” Of the 10 NILs analyzed, 16CLP26 and 16CLP16 were considered useful breeding material for the development of colored waxy maize varieties with relatively high amounts of yield and anthocyanin. Collectively, these results are expected to provide useful information for the development and selection of lines for breeding colored waxy corn varieties at the Maize Research Institute, Gangwon-do Agricultural Research and Extension Services.

Recent advances in high-throughput sequencing technologies have enabled large-scale cost-effective genotypic analyses, and consequently, obtaining reliable phenotypic data has now become a major bottleneck in data-driven plant breeding. In order to construct a phenotype database for commercial rice varieties released by the National Institute of Crop Science, Rural Development Administration, we initiated a systematic phenotype evaluation project, with the aim of investigating the major agronomic traits of Korean rice varieties released during the period between 1979 and 2017. Despite the narrow genetic background, we found that the days to heading (DTH) and culm length (CL) of the 297 Korean rice varieties assessed exhibited wide phenotypic variation under different environments. Under normal planting cultivation in 2018, the DTH ranged from 48 to 104 days in Suwon, 46 to 111 days in Wanju, and 39 to 97 days in Miryang, with CL values ranging from 59 to 134 cm, 55 to 122 cm, and 57 to 106 cm, respectively. During early planting cultivation in 2019, the DTH ranged from 56 to 113 days (Suwon), 58 to 109 days (Wanju), and 58 to 100 days (Miryang), with corresponding CL values ranging from 63 to 119 cm, 55 to 93 cm, and 51 to 115 cm. Despite the difference of one month in planting dates in 2018 and 2019, DTH in the different years and regions showed highly significant positive correlations (r=0.90-0.98), whereas CL showed positive but weaker correlations (r=0.45-0.82). Furthermore, we detected a weak, although significant, correlation between DTH and CL in each environment (r=-0.18-0.35). Analyses of additive main effects and multiplicative interaction (AMMI) were conducted for DTH and CL to identify rice varieties with stable phenotypes under different environments. We anticipate that the findings of this study will provide a useful rice phenotype database to facilitate genotype-phenotype association studies and data-driven rice breeding.

Kernel weight is a vital trait for selecting high-yielding wheat in breeding programs. We evaluated the thousand-kernel weight (TKW), test weight (TW), grain length (GL), grain width (GW), grain thickness (GT), and grain roundness (GR) of 41 Korean winter wheat cultivars over a period of 4 years. Correlation analyses revealed that TKW was positively correlated with GL (r=0.76***), GW (r=0.85***), and GT (r=0.84***), whereas TW was negatively correlated with GL (r=-0.38*) and GT (r=-0.31*). Allelic variation was analyzed for 13 kernel weight-related genes/loci (TaCwi-A1, TaCWI-4A, TaCWI-5D, TaGW2-6A, TaTGW6-A1, TaTGW-7A, TaGS1a, TaSus1-7A, TaSus1-7B, TaSus2-2B, TaCKX6-D1, TaCKX6a02-D1, and TaSnRk2.3). Significant associations between the allelic variation and kernel traits were identified in TaCWI-4A (TW, GL, and GR), TaCWI-5D (TKW), TaGW2-6A (TKW, GL, GW, and GT), TaSus2-2B (TKW, GL, GW, and GT), and TaGS1a (TW). In contrast, we detected no significant association between the allelic variation of TaCwi-A1, TaTGW6-A1, TaSus1-7A, and TaSus1-7B and variations in kernel traits. Also, TaTGW-7A, TaCKX6-D1, TaCKX6a02-D1, and TaSnRK2.3 were found to be monomorphic. The four loci TaCWI-4A, TaCWI-5D, TaGW2-6A, and TaSus2-2B showed significant phenotypic differences, a totalof 10 different haplotypes (AC1-AC10) were observed at four loci among the Korean wheat cultivars. Cultivars with the AC1 haplotype exhibited significantly higher TKW than those with the AC8 haplotype, which comprises alleles for high TKW at all four loci, indicating that additional loci controlling kernel weight might be present in the high TKW cultivars.

In this study, watermelon accessions introduced from the USDA were characterized for 12 morphological characteristics of leaf, flower, fruit, and seed, according to the National Agrobiodiversity Center descriptor list. In addition, to confirm the genetic composition of each watermelon accession, genetic profiling was performed using 20 simple sequence repeat (SSR) markers. A total of 154 watermelon accessions from the USDA were collected from 31 different countries, among which, 12.3% (19 accessions) were from Turkey. Morphological characterization revealed that the accessions displayed a large diversity. Genetic profiling using 20 SSR markers showed that six accessions (K192117, K192028, K193400, K192376, K192499, and K192800) were expected to be inbred lines among the 154 watermelon accessions. The 12 characters scored were analyzed using discriminant analysis of principal components (DAPC). The result revealed 68.1% of the total variability and indicated variations among accessions, mainly based on fruit stripes and fruit shape along the longitudinal section. The accessions were divided into eight groups according to DAPC, although the geographical origin was not a great source for the grouping. Our results will be helpful for the efficient management of germplasms and in understanding and selecting watermelon accessions for the breeding process.

This study was carried out to investigate the variation of 12 isoflavone components among 172 Korean soybean varieties released from 1913 to 2013. Cluster analysis was performed to classify the varieties based on the variation of isoflavone contents. Total isoflavone contents ranged from 206.3 μg/g to 2666.2 μg/g with an average of 837.2 μg/g. By each component, malonylgenistin content ranged from 99.2 μg/g to 1149.1 μg/g with the highest average of 390.0 μg/g, and glycitein content ranged from 0.1 μg/g to 2.4 μg/g with the lowest average of 0.8 μg/g. Among composition groups, the aglycone group contents ranged from 2.2 μg/g to 33.1 μg/g with the lowest average of 10.0 μg/g, and glucoside group contents ranged from 36.9 μg/g to 801.8 μg/g with an average of 202.4 μg/g. The malonylglucoside group contents ranged from 143.6 μg/g to 1796.4 μg/g with the highest average of 599.1 μg/g and acetylglucoside group contents ranged from 3.7 μg/g to 103.9 μg/g with an average of 27.5 μg/g. Varieties with high total isoflavone content were Aga8(2666.2 μg/g), Aga4(2569.3 μg/g), and Aga9(2345.0 μg/g) in bean sprouts group. The low total isoflavone content were observed from Deawang(328.8 μg/g) in soy sauce and paste group, Hanol(599.3 μg/g) in vegetable and early maturity group and Gemjeong1(664.1 μg/g) in cooking with rice group. The first three principal component axises accounted for 89.14% of the total variation observed. Dendrogram constructed using average linkage cluster method revealed that 172 Korean soybean varieties were divided into seven groups with the average distance of 0.8 between groups. The group Ⅰ includes 57.6% of the total varieties, which was the largest group among seven groups, followed by the group Ⅱ that includes 35.5% of the total varieties. However, the other groups were small groups containing less than five varieties. In comparison among the total isoflavone contents according to groups, the highest isoflavone content was observed in group Ⅵ with an average of 2526.9 μg/g, followed by group Ⅳ(1546.6 μg/g) and group Ⅴ(1503.5 μg/g). The others were found to contain low isoflavone content.

This study was conducted to obtain general information for rice breeding materials high in taxifolin content. The taxifolin was isolated from the rice variety, ‘Superhongmi’, and was identified by means of spectral methods and quantitative analysis using a high performance liquid chromatography (HPLC). The taxifolin content of the ‘Superhongmi’ variety was ranged between 32mg and 68mg per 100g seed that differs depending on cultivated regions. The taxifolin content was lower grown at mid north than those at south region. A large amount of taxifolin was found in the aleurone layer of seed as well as in the node of spike of the ‘Superhongmi’. The weight of 1,000 grains was ranged between 23.5g and 27.8g that varied depending on cultivated regions. This variety showed heading in the 6^th of September, and its fertility ratio was about 83% in sejong region. These results suggest that the taxifolin-rich rice variety, ‘Superhongmi’, is a good source of functional and stable food.

Knowledge of the chromosomal constitution of the ancestors of modern soybean will complement plant breeding efforts to improve agronomic and economic characteristics of soybean. Variation block (VB)-based comparison using genome-wide insertion/deletion (InDel) markers was used on a diverse panel of 147 soybean cultivars to assess the impact of chromosomal changes during modern breeding. There were identical variation patterns of the examined InDels consistently appearing in the genome parts arising from parental varieties, indicating that soybean chromosomes in descendants should be all determined by genetic reshuffling of VBs inherited from parental chromosomes. Structure analysis of the accessions through the 202 InDels separated the accessions into four subgroups. Gene introgression revealed by the structure analysis agreed with the fact that a limited number of landraces and elite varieties were introduced and used as donors for breeding soybean cultivars in pedigree analysis. Especially, VBs became more reshuffled over time as a result of the breeding process, which resulted in using breeding parents with new VB-types for improving the end-use value of soybean. Therefore, their clustering using the 202 VB-specific InDels is strongly influenced by the difference in breeding ancestors among the subgroups. This indicates that the 202 InDel markers are very useful for genetic study by analyzing the reshuffling patterns of the parental genomes in the descendant.

In order to develop a core set and new corn variety in Korea, we evaluated the morphological characteristics of 194 maize accessions by examining eight quantitative characteristics. On the evaluation of quantitative traits for 194 maize accessions, they showed the morphological variations in tassel length (35.1±5.0 cm), plant height (226.1±33.7 cm), ear height (86.3±22.6 cm), stem diameter (2.3±0.6 cm), leaf width (9.3±1.1 cm), ear length (14.5±2.4 cm), ear row number (14.1±1.9 row), and 100 kernel weight (24.9±4.4 g). The results of principal component analysis (PCA) indicated that the tassel length, plant height, and ear height greatly contributed to positive direction on the first principal component axis. One-hundred kernel weight contributed to negative direction on the second principal component axis. Thus these morphological characteristics, which contributed greatly in the first and second principal components, might be useful for discrimination among 194 maize accessions. In our study, seven accessions, such as IT026357, IT026441, IT027321, IT033271, IT033591, IT033597 and IT124273, particularly were measured high on yield-related traits. Consequently, the 194 maize accessions used in this study could be used as promising materials for maize breeding programs such as development of new hybrid in Korea.

Molecular markers related to flour qualities of long spike wheat lines were evaluated. Ash, wet gluten and protein content of long spike wheat lines were higher than Keumkang(Korean wheat cv.) but SDS-sedimentation volume(SDSF) was lower. Particle size and lightness of flour of long spike wheat lines showed similar to Keumkang. The high positively correlation was presented between protein content and SDSF, wet gluten and particle size, respectively. However, negatively correlation was between protein content and lightness. Through the analysis of molecular markers, we identified the genotypes of four genes, Glu-A3c, Wx-A1a, Wx-B1a and Wx-D1a. These genes had same genotypes with Keumkang. Six genes, Glu-A1c, Glu-B1c, Glu-D1a, Glu-B3g, Pina-D1and Pinb-D1b, were presented in most of the lines. Two genes, Glu-A1 and Glu-B1b, were related to higher protein contents and wet gluten. The lines containing three genotypes, Glu-D1d, Glu-B3h and Pinb-D1b, had higher ash, protein contents, SDSF and wet gluten, and lightness was darker. Through the results, we expect that long spike type wheat lines are necessary to breed wheat having high yield productivity.

One hundred sixty four wheat (Triticum aestivum L.) lines expressing the long spike were developed by the National Institute of Crop Science, Rural Development Administration. Six of 11 genes showed allelic variation among 164 lines and they were highly related to yield traits containing spike and kernel number, kernel length, 1000-kernel weight and grain yield. Analysis of allelic variation of each gene showed high correlation between allelic variation and agricultural characteristics. Coefficient of correlation between culm length and spike length was the highest 0.436. The heading date of the lines expressed Vrn-D1 allele was late and the lines expressed Vrn-D1 allele had longer spike length and higher number of kernel per spike than other lines. There was no significant difference in agronomic characteristics of analysis of Vrn-B1. Ppd-D1b was related to heading date and higher number of spike/m². Ppd-D1a was corresponded to number of kernel per spike and 1000-kernel weight. Three haplotypes, Hap-L, Hap-6A-G and TaCwi-A1a, were related to 1000-kernel weight.