Soybeans [Glycine max (L.) Merr] are an important source of nutrients including protein, oils and various useful secondary metabolites. Phosphatidylcholine (PC) component serves as a nerve cell membrane material and a choline supplier, so it may improve memory function in subjects suffering from memory impairment and dementia. Content of PC component in soybean seed may depend on genotype and environment. Genotype with high PC content is valuable in breeding project. Fifty-seven soybean genotypes were cultivated at first year. After harvesting, PC contents were analyzed. Content (mg/kg) of PC component was from 7.02 to 19.55. At second year, 111 genotypes including 57 genotype used at first year were cultivated. After harvesting, PC contents were analyzed. Content (mg/g) of PC component was from 0.061 to 12.324.

Sucrose, raffinose, and stachyose are major soluble sugars in soybean seeds. Sucrose is the major source of energy for fermentation and contributes to the sweetness of soybean foods. The soyfood and animal feed markets prefer soybean cultivars with high sucrose because they provide high levels of energy and better tasting food and feed. The objective of this study is to select soybean lines with high sucrose content. A total of 295 soybean genotypes including 13 current cultivars, 34 germplasms, and 248 breeding lines were planted at the field. After harvesting, sucrose contents for 295 genotypes were measured through HPLC method. Wide variation was detected among the 295 genotypes in sucrose content. The sucrose content ranged from 15.1 to 39.0 g. kg-1 in 13 current cultivars. The highest sucrose content was identified in “Dayangkong” (39.0 g. kg-1), whereas was lowest in “Seomoktae” (15.1 g. kg-1). The sucrose content ranged from 9.6 to 47.6 g. kg-1 in 34 germplasms. The sucrose content ranged from 0.9 to 46.4 g. kg-1 in 248 breeding lines.

Soybean is an excellent source of protein for human and animal feed. But, nutritional quality is compromised by a low content of the sulfur amino acid, methionine. The purpose of this research is to screen the genotype with high methionine content. Forty genotypes including current cultivars, breeding lines, and germplasms were evaluated in the for two years. After harvest, random seeds of each genotypes were used to check methionine content by HPLC method. Methionine contents ranged from 1.9 - 5.0 (mg/g) for first year to 2.4 - 4.3 (mg/g) for second year. At first year, three genotypes [76F7-4(1), 86F8-2(1), and 70F7-1] had high content of methionine. At second year, three genotypes [Jinnon#1, daalkong, 86F8-2(1)] had high content of methionine. Genotype, 86F8-2(1) had high content of methionine at both years. Also, effect of environment on methionine content was observed. However, methionine content is a very different from genotypes.

Soybean cyst nematode (Heterodera glycines Ichinohe) is one of the serious soybean [Glycine max (L.) Merr.] pests in major soybean producing countries. The objective of this study was to investigate of Heterodera glycines type using the five SCN infested soybean field soils and was to evaluate resistance to the soybean cyst nematode HG 2.5.7 type on soybean varieties and germplasms. The five SCN contaminated soil samples were collected from the three provinces on November 2011 in Korea, and eggs were cultured on early spring season in 2012. For the second study, a total fifty nine soybean varieties and germplasms were tested by infestation of HG type 2.5.7 in the greenhouse. Soybean cyst nematode HG types were investigated from five locations, HG 2 (race 1) type at Donghae, HG 2.5 (race 1) type at Jeongseon and Hapcheon, HG type 2.5.7 (race 1 or 5) at Yeongwol, and HG 1.2.7 (race 5) type at Haenam locations in present study. No Korean soybean varieties and germplasms were observed with SCN resistant trait to the HG type 2.5.7. Average SCN female index were calculated with 82.7% in 59 plant materials. Our results could be provided useful information to develop a SCN resistant cultivar in Korea.