A comprehensive evaluation of 515 Korean wheat germplasms, including cultivars, experimental lines, and landraces, was conducted over 2 years under upland field conditions to characterize major agronomic and grain traits. Allelic variation at 13 key functional loci was assessed using Kompetitive Allele-Specific PCR (KASP) and PCR-based markers. The winter-type vrn-A1 with a single copy (CNV=1; 40.2%) advanced heading by approximately 5 days compared to multiple-copy genotypes, and winter-type vrn-B1 (88.5%) advanced heading by 2 days compared to the spring-type. The photoperiod-insensitive alleles Ppd-B1a (5.6%) and Ppd-D1a (76.3%) advanced heading by 3 and 4 days, respectively, with a combined effect of up to 6 days. Semi-dwarfing alleles Rht-B1b and Rht-D1b showed reduced culm lengths of 2.1 cm and 4.7 cm, respectively, and the Rht-B1a/Rht-D1b genotype was 6 cm shorter than Rht-B1a/Rht-D1a. The Pina-D1a/Pinb-D1a genotype had the lowest kernel hardness value (32.2), whereas Pina-D1b/Pinb-D1a had the highest (60.5). The thousand kernel weight ranged from 36.1 mg to 42.5 mg depending on the allelic combinations of TaCwi-A1, TaGW2-6A, and TaSus2-2B. Cultivars and experimental lines were clearly distinguished from landraces based on phenotype-based clustering, with the majority of cultivars (81.6%) and experimental lines (68.3%) grouped into cluster III. In contrast, landraces were predominantly distributed in clusters I (55.1%) and II (29.2%). Random forest analysis identified four genes, Ppd-D1, Pina-D1, Pinb-D1, and WAPO-A1, as major contributors to cluster classification. Cluster III was highly enriched with alleles favorable for earliness (Ppd-D1a, 98.3%) and grain hardness (Pina-D1b and Pinb-D1b, 57.9%). WAPO-A1b, an allele associated with an increased spikelet number per spike, was more frequently observed in clusters I (94.6%) and II (79.1%) than in cluster III (58.4%).

Recently, crossbreeding between Asian rice (O. sativa) and African rice (O. glaberrima) has become an important solution for hunger refugees and food problems in Africa by improving grain yield. O. glaberrima exhibits important traits such as stress tolerance, and genetic diversity evaluation and structural analysis of agronomic traits have been conducted. In this study, 11 yield-related agricultural traits were analyzed in 45 lines of O. sativa and 28 lines of O. glaberrima under Korean climatic conditions. Through cluster analysis using the investigated yield-related traits, O. sativa and O. glaberrima were grouped into clusters by characterizing the remaining traits, except for the number of spikelets, grain width, and grain thickness. The number of spikelets was highly influenced by the environment and had the greatest variation, whereas grain width showed the least variation. In addition, rice yield components are quantitative traits, and in breeding to improve yield, it is important to analyze the interaction of agricultural traits and the influence of the environment to maintain an optimal balance and improve plant potential. Although O. sativa was found to exhibit different agricultural traits depending on its ecotype, it still belonged to the same group when clustered. The results of this study provide basic information on the yield-related agronomic characteristics of O. sativa and O. glaberrima under Korean climatic conditions, suggesting that O. glaberrima can be used as breeding material to diversify Korean rice genetic resources.

‘Jinhyang’ is a fragrant pear bred in 2019. Field crossings to breed fragrant pears were conducted in 1984 at the Pear Research Center of the National Institute of Horticultural and Herbal Science. The maternal and paternal parents were ‘Okusankichi’ (IT254489) and ‘Hori’ (IT226291), respectively. The 84-16-5 line, which had a good fragrance, was first selected in 2007, and regional adaptation tests were conducted from 2011 to 2019 in five regions (Suwon, Chuncheon, Jinju, Yecheon, and Naju). The morphological characteristics of ‘Jinhyang’ include vigorous spreading tree form, brown-colored one-year-old shoot, elliptical leaf blade, round leaf tip, and white-colored flowers. The full bloom date was April 11, and the harvest date was in late September. The fruit of ‘Jinhyang’ weighs 439.9 g and has a soluble solid content of 13.0 °Brix, with a good sugar-acid balance and abundant juice. Analysis of the fragrance components of ‘Jinhyang’ revealed the presence of a large amount of fragrant volatile compounds compared to that of the standard cultivar ‘Niitaka’. In particular, ‘Jinhyang’ contains ethyl hexanoate and ethyl butanoate, which are known volatile compounds generated by pineapple and mango. Because of its strong uprightness, cultivation management, such as shoot bending, is necessary to maintain flower buds (Registration No. 9387).

Paprika (Capsicum annuum) cannot grow or set fruit in temperatures that are higher than the optimal level. This study assesses the characteristics of 52 paprika accessions introduced from the agrobiodiversity center and the world vegetable center during a high temperature period in order to develop heat tolerant lines. As a result of controlling the temperature in two greenhouses by side ventilation and fogging system, the average daily temperature of the high temperature regime was 34.3℃, which was 2.4℃ higher than that of the normal temperature regime. Plant height, stem diameter, fruit set, fruit weight, fruit shape, pericarp thickness, soluble sugar content, yield, and marketable fruit development rate were all investigated as vegetative and reproductive growth-related parameters. Plant height, fruit weight, pericarp thickness, and yield were all reduced during high temperature treatment. Six germplasm lines (T12, T15, T26, T29, T32, and T36) were selected as high-temperature tolerant lines based on these parameters. The selected lines will be used to breed heat-tolerant cultivars as well as crossbreeding for genetic analysis.

“CenSall” is a cultivar that can be easily consumed due to its thin fruit skin and small core. “Whangkeumbae” and “Minibae” were crossed in 1999 to breed this pear cultivar. After the first selection in 2010, regional adaptation tests were conducted in five regions (Suwon, Chuncheon, Jinju, Yecheon, and Naju) from 2011 to 2017. The selected tree exhibited a vigorous spreading form and white flowers. “CenSall” contains 165 mg of pollen per 100 flowers; therefore, it can be used as a pollinator. However, it is sensitive to scabs, and thus, cultivation management to control scab is necessary. “CenSall,” harvested in early August, had a fruit weight of 336.3 g and soluble solid contents of 10.2 °Brix, hardness of 2.4 kg⋅8 mmØ^-1, and the fruit skin color was yellowish green. The fruit has many edible portions, accounting for 94.5% of the entire flesh. Notably, only 22.7% of the seeds developed normally but fruited stably. The thickness of the hypodermis was 62.57 μm, which was half the thickness of the main cultivar “Niitaka” (113.49 μm). The cuticle developed without a cork layer, fruit skin was smooth, and it could be eaten with the peel (Registration No. 8046).

The breeding
objective
for crops changes constantly due to environmental changes, customer requirements, and farming convenience, among other factors. As breeding takes a long time, suitable mating candidates must be obtained from the beginning. In this study, we propose a breeder-friendly system and datasets. We investigated 11 traits that affect adaptation to the cultivation environment in Jeju Island using 27 buckwheat germplasms and selected good germplasms for breeding new cultivars. Data on the various traits of the target crop could assist breeders or researchers in identifying the traits of each genetic resource that will facilitate the development of new cultivars that suit the requirements of customers. Therefore, this study suggests establishing a breeder-friendly system and datasets in GenBank.

To compare agronomic and seed traits of 135 common bean landraces originating from Korea, Bulgaria, and El Salvador, we evaluated 20 morphological traits and performed principal component analysis (PCA). In the PCA, the first and second principal components accounted for 55.15% and 15.97% of the total variance, respectively. The first component showed a strong positive correlation with seed size and 100-seed weight, whereas the second component produced a strong negative correlation with days to flowering and days to maturity, indicating that these traits may explain the differences between landraces originating from different countries. Landraces from Korea showed higher variation in days to flowering and days to maturity; those from Bulgaria produced larger and heavier seeds; those from El Salvador produced smaller and lighter seeds and flowering and maturity occurred earlier. In addition, the landraces from El Salvador had relatively lower diversity compared to those from other countries, as they were grouped within a small cluster in the PCA. These evaluation results may provide important information for selecting breeding materials, and diversity analyses of landraces from different countries provide information for securing genetic resources.

Plant germplasm is a part of living genetic resources, including seeds and plant materials, such as roots, leaves, and stems, and should be conserved and managed to maintain ecological biodiversity and to consistently generate the product and supply food crops. Plant germplasm can be categorized based on various genetic traits such as race, and clustering based on similar genetic traits is an efficient method for managing large numbers of germplasms. Therefore, we developed an algorithm, termed cacGMS (Clustering Analysis for Categorical genetic traits of germplasms in Genebank Management System), using categorical variables which statistically differentiate the datatype of genetic traits such as seed-coat color, seed shape, and flower color. Briefly, using Newman’s modularity method, cacGMS combines the hierarchical clustering algorithm using the Ward2 method and representative-based algorithms such as K-medoids, and it regroups all germplasms using germplasm core sets. We tested cacGMS using 2,378 pepper germplasms with 46 different categorical genetic traits, and it exhibited better performance than the hierarchical and K-medoids algorithms for the average distance among clusters (0.4534) and entropy (1.2672). Moreover, cacGMS showed better performance in terms of threshold (from 15 to 30) for genetic traits than other algorithms and provided similar results in a test run using tomato germplasm. From these results, we expect that cacGMS will be a useful tool for managing each group with numerous plant germplasms and facilitate the analysis of other studies, such as analysis of representative characteristics of clustered germplasms and of correlations among germplasms in a particular cluster.

Pepper mild mottle virus (PMMoV), a member of the genus Tobamovirus, is one of the most threatening pathogens affecting commercial pepper production, and it is classified into pathotypes P_1,2 and P_1,2,3. As chemical and physical treatments show limited success in controlling PMMoV, resistant pepper varieties are considered the most effective means of disease control. Two hundred pepper germplasms, including 167 accessions of Capsicum chinense and 5 reference accessions known as resistant L alleles, were assessed using a bioassay to select germplasms resistant to PMMoV. Six accessions, including IT261210, were resistant to both PMMoV pathotypes P_1,2 and P_1,2,3 as they developed necrotic local lesions only on inoculated leaves, whereas no symptoms were observed on the upper leaves. Moreover, RT-PCR results of the upper leaves of these accessions were also negative. Thus, the identified accessions may be a novel source of genetic resistance against present or emerging new pathotypes and may be useful for differentiating L alleles.

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.

Fusarium wilt is a serious disease that causes damping-off, serious wilt symptoms, or death in melon. The aim of this study was to evaluate the resistance of melon germplasm to Fusarium wilt and select promising disease-resistant accessions for further applications. Resistance to Fusarium wilt was examined in 216 melon germplasms by the root-dipping inoculation method with Fusarium oxysporum f. sp. melonis fungal isolate KACC43206 (race 2). Inoculated seedlings were incubated for four weeks and assessed for disease symptoms using indices ranging from index 1 (no symptoms) to 5 (plant wither). A total of 34 accessions showed a disease index < 2.0. Disease indices of 10 accessions were 1.0 four weeks after inoculation. The resistant accessions of melon are expected to help in breeding commercial varieties with Fusarium wilt resistance.

Rice landrace germplasms are highly valuable because of their wide genetic variation. Their traits have not been selected by modern breeders but by nature, thus, these traits and the gene associated with them have tremendous potential to improve modern rice cultivars. The first step to utilize this potential is to conduct a thorough evaluation of the target traits to select superior germplasm for a breeding program. Here, with 386 Korean landrace germplasms, we evaluated mesocotyl elongation traits which possibly promote direct seedling cultivation in rice. Mesocotyl length ranged from 0 mm to 28 mm. Among the tested landraces, we selected and reported the top 20 performing landraces whose mesocotyl length were larger than 16 mm. The previously reported agronomic traits for the selected 20 landraces were also listed for breeders to promote the utilization of these germplasms in breeding programs.

A statistical analysis of 9,771 non-glutinous rice in breeding line germplasm collected from Korea (2,836), China (2,136), Japan (1,219), and the Philippines (1,213) was conducted using normal distribution, variability index value (VIV), analysis of variation (ANOVA) and Ducan’s multiple range test (DMRT) based on the data obtained from NIRS analysis. According to the normal distribution, the average protein content was 7.9%, and non-glutinous rice ranging over 10% amylose had 23.6% average content. Most resources were between 5.3 and 10.5% in protein content, and 15.7 and 31.5% in amylose content. The VIV was 0.54 for protein, and 0.83 for amylose. The average amylose content was 25.18%, 24.54%, 22.08%, and 21.47% in Filipino, Chinese, Korean, and Japanese resources, respectively, wheereas the average protein content was found to be 8.19%, 7.79%, 7.58%, and 7.42% in Filipino, Chinese, Korean, and Japanese resources, respectively. The ANOVA of amylose and protein content showed significant differences at the level of 0.01. The F-test value was 412.2 for amylose content, and 108.4 for protein when compared with the critical value of 3.78. The DMRT of amylose and protein content showed significant differences (p<0.01) among resources from different countries. The Filipino resources had the highest level of amylose and protein content, whereas; the lowest level of amylose and protein content were found in Japanese when compared with resources of other origins. These results are recommended as helpful materials in the field of breeding.

Identification of Fusarium oxysporum f. sp. raphani and investigation on fusarium wilt development by isolates and inoculation methods were conducted to establish a screening method for fusarium wilt-resistance in radish (Raphanus sativus L.) germplasm. Pathogenicity of F. oxysporum f. sp. raphani isolate, Heonggye-1 and Heonggye-2, to radish plants was confirmed by seedling test. Radish seedlings were inoculated by root-dipping and soil-drenching with or without root-wounding. For Heonggye-1 isolate, mean disease indexes were 4.13 and 3.91 by root-dipping and soil-drenching with root-wounding, respectively, but those were 1.87 and 1.88 without root-wounding. For Heonggye-2 isolate, mean disease indexes were 3.83 to 4.37 regardless of inoculation methods. Two-hundred sixty accessions of radish germplasm collected from 9 countries of Asia and Europe were evaluated for fusarium wilt-resistance by soil-drenching with root-wounding with Heonggye-2 isolate. Fifty-four resistant accessions with higher than 70% of the percentage of resistant seedlings in accession (P_R) and lower than 20% of the percentage of susceptible seedlings in accession (PS) was found. Eighteen susceptible accessions with lower than 20% of P_R and higher than 50% of PS were selected. These accessions could be used as breeding and research materials after re-evaluation of disease-resistance and characterization of agronomical traits.

Bakanae (foolish seedling) disease caused by Gibberella fujikuroi creates serious problems in the foremost rice growing countries. This study was conducted to identify new resistance genetic sources to Bakanae disease. Bioassay showed that 11 varieties including Gwangmyeongbyeo, Hawn, Wonseadaesoo, Erguailai etc. were resistant to bakanae disease among 254 rice germplasm. Mismatch ratio between phenotype on bakanae disease bioassay and allele type of RM9, a SSR marker closely linked the bakanae disease resistant QTL, qBK1, were 38.3%. These results suggest that RM9 might be used for selecting qBK1, but it cannot be used for wide range of rice germplasm. Resistant germplasm in this study might be have resistant genes different from qBK1. The eleven varieties resistant to selected in this study will be used to identify new resistant alleles or genes to improve bakanae disease resistance in rice.

This study was carried out to evaluate the oil contents and fatty acid compositions of 379 soybean germplasm accessions which is composed of 128 Korean, 214 Chinese and 37 USA accessions, and to select useful resources for the development of high oil content and quality fatty acid varieties in soybean. Korean and Chinese germplasm accessions were obtained from the National Agrobiodiversity Center, National Academy of Agricultural Science, Rural Development Administration, and USA accessions from the Plant Genetics and Breeding Laboratory of Kyungpook National University, Korea. The oil content ranges from 12.7~26.0% with an average of 19.1% among accessions. The average contents and ranges of palmitic and stearic acid, saturated fatty acids (SFA), were 10.6% with a range of 4.1~18.1% and 2.9% with a range of 1.9~ 12.7% respectively, while those of oleic, linoleic and linolenic acid, unsaturated fatty acids (USFA), were 28.2% with a range of 15.3~56%, 51.2% with a range of 24.4~68% and 7.1% with a range of 3.4~11.1% respectively. The average linoleic(ω -6)/linolenic(ω-3) acid ratio was 7.5 ranging from 3.8~17, and the average SFA and USFA contents were 13.5% ranging from 6.7~21.7% and 86.5% ranging 78.3~93.4% respectively. Accessions with better essential properties were selected as useful resources for the development of high oil content and quality fatty acid varieties. Three accessions, Suinong 14, Dongnong 434 and Dongnong 46 from China contain oil higher than 25.0%, while five accessions including KLG 12073 and KLG 12074 from USA, Jilin 14 from China, Kwangan and Bongeui from Korea contain oleic acid higher than 50%. Eight accessions including KLG12083 and KLG12081 from USA contain linoleic acid higher than 60%. Seven accessions including KLG 12093 and KLG12096 from USA contain linolenic acid lower than 4%. Five accessions, KLG12074 and KLG12073 from USA, Kwangan and Bongeui from Korea, and Dongnong 47 from China were low linoleic acid(ω-6)/linolenic(ω-3) ratio resources with lower than 4.5.

Soybean [Glycine max. (L.) Merr] is one of the most important legumes in the world. However, soybean varieties are sensitive to flooding stress and their seed yields are substantially reduced in response to the flooding stress. 192 soybean germplasm collection was screened to identify flooding tolerant germplasm at an early vegetative growth stage (V1). Soybean plants at V1 stage were waterlogged for 4 to 10 days. To evaluate flooding tolerance, survival rate were investigated as a time dependent manner. Jangbaegkong, Danbaegkong, Sowonkongkong, Socheong2 and Suwon269 showed flooding tolerance, while Shillog, T201, T181, NTS1116 and HP-963 showed flooding sensitivity. We also investigated effects of flooding stress on soybean morphology. The adventitious root development was greatly increased in flooding tolerant plants compared to it in flooding sensitive plants. In addition, root length and root number were analyzed. The significant reduction of root length and root number was observed in flooding sensitive plants. Thus, these results indicate that the morphological changes in roots are important for acclimation to flooding stress. Taken together, the relationship between the morphological changes in the roots and flooding tolerance may be useful in selecting a flooding tolerant soybean germplasm.