Liver cancer represents a major health problem with steadily increasing incidence rates. Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most common cause of cancer-related death. This study was conducted in order to investigate the gross findings following treatment with diethylnitrosamine (DEN) in mice. Sixteen male and female mice (B6C3F₁), initially 20 days of age, received intraparietal injection (20 mg/kg three times for a period of two weeks, IP) or were given drinking water (DW) containing 50 ppm DEN; all mice were sacrificed at the 80^th week of experiments. Hepatocellular adenoma (HCA) and HCC were induced in B6C3F₁), mice by administration of DEN. The numbers of HCA and HCC were 7.4±1.72 (IP) and 7.2±0.86 (DW) in male mice. However, no significant difference was observed between the DW and IP groups. The numbers of HCA and HCC were 0.67±0.33 (IP) and 2.0±0.63 (DW) in female mice. This study showed a tendency for high incidences of liver tumor with long-term exposure of newborn animals by drinking water.

Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The objective of this study was to identify the putative QTL for foxglove aphid resistance in wild soybean, PI 366121, (Glycine soja Sieb. and Zucc.). One hundred and forty one F2-derived F8 recombinant inbred lines developed from a cross of susceptible Williams 82 and resistant PI 366121, were used. The phenotyping of antibiosis and antixenosis was done through choice and no-choice assays with total plant damage (TPD) and primary infestation leaf damage (PLD); a genome-wide molecular linkage map was constructed with 504 single nucleotide polymorphism markers utilizing a GoldenGate assay. Using inclusive composite interval mapping analysis for foxglove aphid resistance, one major candidate QTL on chromosome 7 and 3 minor QTL regions on chromosome 3, 6 and 18 were identified. The major QTL on chromosome 7 showed both antixenosis and antibiosis resistance responses. However, the minor QTLs showed only antixenosis resistance response. The major QTL mapped to a different chromosome than the previously identified foxglove aphid resistance QTL, Raso1, from the cultivar Adams. Also, the responses to the Korea biotype foxglove aphid were different for Raso1, and the gene from PI 366121 against the Korea biotype foxglove aphid were different. Thus the foxglove aphid resistance gene from PI 366121 was determined to be an independent gene to Raso1 and designated to Raso2. This result could be useful in breeding for new foxglove aphid resistant soybean cultivars.

Foxglove aphid, Aulacorthum solani (Kaltenbach), is a Hemipteran insect that infected a wide variety of plants worldwide and caused serious yield losses in crops. The foxglove aphid resistance gene, Raso2 was previously mapped from PI 366121 (Glycine soja Sieb. and Zucc.) to a 26cM marker interval on soybean chromosome 7. The development of additional genetic markers, which are mapped closer to Raso2 were required to accurately position the gene to improve the effectiveness of marker assisted selection. The objective of this study was to narrow down the putative QTL region, which is responsible to foxglove aphid resistance in PI366121 using recently developed high-density 180K Axiom SoyaSNP genotyping array. One hundred and forty one F8-derived F12 recombinant inbred lines developed from a cross of susceptible Williams 82 and resistant PI 366121, were used to generate a fine map of Raso2 interval. The phenotyping of antibiosis and antixenosis was done through choice and no-choice assays with total plant damage (TPD) and primary infestation leaf damage (PLD). The composite interval mapping analysis showed that the physical interval between two flanking makers, which was corresponding to Raso2, was narrowed down to 500kb on the Williams 82 genome assembly (Glyma2.0), instead of 4Mb in the previous report using Goldengate assay. In the Raso2 interval, there are about 60 candidate genes, including 4 of NBS-containing putative R genes. This result could be useful in breeding for new foxglove aphid resistant soybean cultivars.

The depletion of stratospheric ozone has resulted in increased amount of ultraviolet-B radiation (UV-B: 280-320 nm) reaching the Earth’s surface and could cause significant biological effect in plants. In this study, putative quantitative trait loci (QTL), which is responsible to UV-B resistance in soybean, was identified using recently developed high-density 180K Axiom SoyaSNP genotyping array. A population of 115 recombinant inbred lines (RILs) derived from a cross between susceptible Keunolkong and resistant Iksan 10 was analyzed. A total 8,970 polymorphic SNP markers were used to construct linkage map. The both parents and RILs were grown with supplemental UV-B radiation in a greenhouse condition. Three categories of UV-B induced morphological damage, degree of leaf chlorosis, leaf shape change, and total plant damage were evaluated. Using composite interval mapping analysis, one major QTL associated with all of the phenotypic traits was detected on 7.7cM of soybean chromosome 7 with 22 of LOD score accounting for about 60% of phenotypic variance. Also, the allele from Iksan 10 were responsible for the UV-B resistance. Thus, the UV-B resistance QTL on chromosome 7 from Iksan 10 was designated to qUVBR1, corresponding to 30kb on the Williams 82 genome assembly (Glyma2.0) including 7 candidate genes. This result could be useful in breeding for new foxglove aphid resistant soybean cultivars. In addition, these results provided useful information not only for marker-assisted selection for UV-B resistance soybean, but also for the future identification of putative candidate genes, responsible for UV-B resistance in soybean.

“Younbaek”, a new noodle making wheat cultivar, was developed from the cross between “Keumkang” with white grain color and “Tapdongmil” by the Honam Agricultural Research Institute(HARI), National Institute of Crop Science (NICS), RDA, Korea in 2005. Amon

보리종자의 노화과정에서 일어나는 생리화학적인 활성을 비교 검토하여 종자세를 예측하기에 적합한 방법을 구명하기 위하여 새쌀보리, 부호보리 및 두산2002의 3품종을 ‘Wire-mesh tray’ 방법으로 41℃ , 상대습도 100%로 조절하여 1일에서 8일간 인위노화시켰다. 종자세의 지표로서 발아율 유아의 길이로 표시한 값과 각종 매개면수와의 관계를 비교하였다. 발아시험에 의한 방법이 보리종자의 퇴화진전을 확실히 반영해 주고 있으며, ATP 검정과 GADA 검정방법을 제외한 저온발아시험, 전기전도검정 및 테트라조리움 검정방법은 보리 종자세평가에 적합한 방법임을 알 수 있었다. 특히 저온발아시험에 의한 유아장과 데트라조리움 검정법이 가장 효과적인 방법임을 알 수 있었다.