• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.1
• /
• pp.95-102
• /
• 1996

This investigation was conducted to investigate if germination rate, degree of solute leakage and water uptake rate of seeds are a meaningful information for the selection criteria among soybean genotypes and to find out their characteristics in the variable temperature and moisture conditions encounted during long-term warehouse storage. Germination rate in soybean sprouting box and petri dish differed largely among genotypes stored for twenty months but there was little difference when stored for eight months. Length of hypocotyl was shorter at twenty months of storage than at eight months. Degree of solute leakage of Paldalkong and Pulmuwon was twice higher than that of SS88038 lines at twenty months of storage. In 30 minutes after imbibition, water uptake rate in all genotypes stored for twenty months was faster than these stored for eight months, and water uptake rate in Paldalkong and Pulmuwon stored for eight months was 1.5 and 2 times faster than in SS88038 lines. In correlation coefficients, the germination ability and emergence exhibited significantly negative correlation with degree of solute leakage at twenty months of storage. Water uptake rate in soybean seeds stored for eight months had highly significant positive correlation with degree of solute leakage in 30 minutes and one hour after imbibition while for twenty months of storage, it had highly significant positive correlation with that in 30 minutes, one hour and three hours after imbibition. In eight months of storage, the number of open micropyle had positive correlation with water uptake rate at 30 minutes after imbibiton. But in seeds stored twenty months, it wasn't correlated with water uptake.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2000.04a
• /
• pp.126-127
• /
• 2000

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2001.05a
• /
• pp.232-233
• /
• 2001

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47 no.4
• /
• pp.319-322
• /
• 2002

Soybean cyst nematode (Heterodera glycines Ichinohe; SCN) is an important soybean pest and the use of resistant cultivars is the effective method to reduce or eliminate SCN damage. However, breeding for SCN resistance is difficult and expensive by the oligogenic nature of the resistance and genetic variability in the pathogen. Fortunately, SCN resistance loci, rhg1 and Rhg4 are generally accepted as a necessity for the development of resistant genotypes using any source of resistance. In this study, resistance of 44 Korean soybean cultivars to SCN was tested using two molecular markers. Seonheukkong and Pokwangkong were the homozygous to rhg1 locus. Seven cultivars were susceptible to SCN based on Satt309 marker linked rhg1 locus. All Korean cultivars estimated in this study were recessive homozygous to Rhg4 locus and were susceptible in the PCR reaction using primer 548/563 linked to the Rhg4 locus conferring resistance to SCN race 3. Among 44 cultivars estimated, seven cultivars were susceptible to SCN in both Satt309 and primer 548/563 markers. Based on both Satt309 and primer 548/563 markers, there is no resistant cultivar to SCN in Korea. Therefore, SCN resistant cultivars need to be developed in the future. These two markers can be used for improving SCN resistant cultivars.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.50 no.1
• /
• pp.60-66
• /
• 2005

Pod shape of twenty soybean (Glycine max L. Merrill) genotypes was evaluated quantitatively by image analysis using elliptic Fourier descriptors and their principal components. The closed contour of each pod projection was extracted, and 80 elliptic Fourier coefficients were calculated for each contour. The Fourier coefficients were standardized so that they were invariant of size, rotation, shift, and chain code starting point. Then, the principal components on the standardized Fourier coefficients were evaluated. The cumulative contribution at the fifth principal component was higher than $95\%$, indicating that the first, second, third, fourth, and fifth principal components represented the aspect ratio of the pod, the location of the pod centroid, the sharpness of the two pod tips and the roundness of the base in the pod contour, respectively. Analysis of variance revealed significant genotypic differences in these principal components and seed number per pod. As the principal components for pod shape varied continuously, pod shape might be controlled by polygenes. It was concluded that principal component scores based on elliptic Fourier descriptors yield seemed to be useful in quantitative parameters not only for evaluating soybean pod shape in a soybean breeding program but also for describing pod shape for evaluating soybean germplasm.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.1
• /
• pp.17-21
• /
• 2001

Soybean mosaic virus (SMV) resistance of Korean recommended soybeans was evaluated naturally and by mechanical inoculation in Suwon. Based on the differential reaction of forty-four soybean genotypes tested to nine different SMV strains, soybeans were classified into twenty-four groups. Myeongjunamulkong and Ilpumgeom-jeongkong showed a high degree of resistance to nine SMV strains, having no symptom. The other cultivars produced various reactions according to inoculation of each SMV strain: symptomless, mosaic or systemic necrosis. Only five cultivars such as Kwangankong, Eunhakong, Tawonkong, Namhaekong, Sobaegnamulkong were totally susceptible to every strain. There was variation in disease incidence. Soybeans, having the highest levels of resistance to G5H and G7H in the greenhouse, showed the lowest levels of SMV incidence in the field of Suwon. Myeong-junamulkong, Ilpumgeomjeongkong, Soyangkong, Pungsannamulkong, Sodamkong, Jangmikong, Geomjeong-kong2, Pureunkong, Sinpaldalkong2, Duyoukong, and Geumgangkong were fairly resistant to SMV. And SMV incidence of Taekwangkong, Saealkong and Baegunkong was over 45% with symptom of bud necrosis. And soybeans, highly resistant to SMV in the field and the greenhouse, were mainly derived from Jangyeobkong and Hwang-keumkong resistant to G1-G7.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.188-188
• /
• 2022

Our previous study identified a resistance locus to Phytophthora sojae (isolate 2457) in an interval of 3.8-4.7 Mbp on chromosome 3 via genetic mapping using a 'Daepung'×'Daewon' recombinant inbred population. Since differential gene expression between Daepung (susceptible) and Daewon (resistant) after inoculation of P. sojae is unknown, RNA sequencing was carried out to compare transcriptomic changes between the two genotypes following inoculation with P. sojae isolate 2457. The two varieties were inoculated using hypocotyl inoculation at the VC stage and stem tissue of 1 cm above and below of the inoculated site were sampled at 0, 6, 12 hours after inoculation (hai), respectively. Differentially expressed genes (DEGs) under same cultivar in different time point and Daepung vs. Daewon in same time point were investigated. In comparison of Daepung vs. Daewon at 12 hai, a total of 3,513 DEGs were identified, including two nucleotide-binding site-leucine rich repeat (NBS-LRR) genes (Glyma.03g034800 and Glyma.03g034900) that are located in the previously reported resistance locus on chromosome 3. In addition, 14,966 DEGs were detected between 0 vs. 6 hai, containing one of candidate genes (Glyma.03g035300). This gene was upregulated by up to 4-fold in Daewon and Daepung. Additional results will be further discussed in the presentation. This study will provide valuable information for soybean crop improvement.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.8 no.1
• /
• pp.69-81
• /
• 1970

1. Four soybean varieties in pure stand and mixtures were grown in 20 competition treatments of genotypes at within-row spacings of 5, 10, 20, 40, and 80 cm and were investigated in 10 characters for different genotypes. 2. Yield, weight of 100 seeds, height, number of branches, pods per plant, and seeds per pod were highly significant for within-row spacing treatment. 3. There was no spacing treatment effect for number of nodes and days to flower. Maturity did not respond equally in four varieties for spacing effect. 4. Fruiting period was influenced by spacing treatment. Height and number of branches were increased as within-row spacings were increased. Seed yield per area was increased oppositely. 5. Difference between fertilizing and non-fertilizing treatment was not significant in this experiment. At 80 cm spacing no competition effect occurred for yield. 6. In the competition effect, Kumkang Daerip was strong competitor ani Chungbuck Back and Shelby were weak competitors. 7. The within-row spacing of uniformity in roder to increase yield per area was proved as 20 cm in this study. 8. Oil percent was increased as spacings were increased and protein percent was as spacings were decreased.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.4
• /
• pp.334-340
• /
• 2001

Two different types of molecular markers, simple sequence repeat (SSR) and single nucleotide polymorphism (SNP), were used to measure genetic diversity among five Korean, eight Thai, and three wild soybeans. For SSR analysis, a total of 20 markers were surveyed to detect polymorphisms. For SNP analysis, four primers were designed from consensus sequence regions on disease resistance protein homolog genes, and used to amplify the genomic region. The PCR products were sequenced. A number of polymorphic SSR and SNP bands were scored on all genotypes and their genetic similarity was measured. Clustering analysis was performed independently on both types of markers. Clustering based on SSR markers separated the genotypes into three main groups originated from Korea, Thailand, and wild soybeans. On the other hand, two main groups were classified using SNP analysis. It seemed that SSR was more informative than SNP in this study. This may be due to the fact that SNP was surveyed on the smaller genomic region than SSR. Grouping based on the combined data of both markers revealed similar results to that of SNP rather than that of SSR. This might be due to the fact that more loci from SNP were considered to measure genetic relatedness than those from the SSR.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.5
• /
• pp.437-441
• /
• 1993

The improvement of superior black soybeans could be accomplished through maintenance and use of black soybean collections. A collection of 965 black soybean lines currently grown by farmers was made in 197 locations on spring, 1991. This study was carried out to evaluate them as useful germplasm. Seed characteristics of black soybean collections were evaluated for black soybean breeding for seed quality. The 100-seeds weight of 929 black soybean genotypes were distributed from 6.9 to 48.1 gram. The maximum and minimum 100-seeds weight were derived from Chungnam and Jeonbuk province, respectively. l00-seeds weight was heavier in middle and late maturity group, as maturity was later, whereas no tendency was shown in early maturity group. Length, width and thickness of the collected black soybean seeds were 9.5$\pm$1.5mm, 7.3$\pm1.3mm and 7.3$\pm1.2mm, respectively. Black soybean collections with yellow seed embryo was 72% and the others were green seed embryo.