When we carried out an anti-stress study using the extracts of A. senticosus, R. coreanus, F .japonica root, and A. fruticosa fruit grown in Korea, the results showed that blood cell counts returned to normal levels fastest with R. coreanus after stress application. The total WBC count was decreased in mice due to stress, whereas the number of lymphocytes was increased. The serum glucose level was higher in the control group compared with the comparative stress group. The weight of each organ to returning to normal level was significantly faster in those mice treated with the extracts compared with those in control groups. Especially, it even return to that of normal level with R. coreanus extract, suggesting that the administration of the plant extracts in this study would affect hormonal activities in the body to increase immune activities. F. japonica root that showed the highest anti-stress activities maybe effective for lipid and carbohydrate metabolism. These results would provide basic data to examine anti-stress effects of natural plants. Further in-depth studies could contribute in the development of functional plant materials with anti-stress activities.

Gibberellic acid did not affect ethylene production, whereas gibberellin biosynthesis inhibitors triggered ethylene production in dormant tubers. Gibberellic acid did not induce sprouting of dormant tubers, however, treatment of gibberellin biosynthesis retardants enhanced sprouting rates. Sprouting rate in ancymidol-treated tubers was highest among gibberellin biosynthesis retardants. Sprouting rate of tubers treated with ancymidol increased to 91.4~% . Batatasin-III content in GA3 treated tuber was increased in the highest concentration (30~mug~;I-1) . Tubers treated with mepiquat chloride, Batatasin-I was increased steadily, but contents of Batatasin-III and V showed dramatic decrease at the 1,000~mug~;I-1) concentration. This infers that gibberellin biosynthesis retardants play key roles in promoting breaking dormancy on dormant tubers of Chinese yam.

“Cheongsun-OmiJa”, a new cultivar of Schisandraceae vine (Schisandra chinensis Baillon) was developed at Jinan Medicinal Herbs Experiment Station, Jeollabuk-do Agricultural Research and Extension Services in 2002. Collections was made on local lines from

Two compounds from Gomisin N and Gomisin A were isolated from the fruits of Schizandra chinensis Baillon. The highest extraction yield as 21.36% was observed in the ethanol extract, compared to the yield obtained form the water extract. The extraction yields of the single compounds were measured to be 0.13 and 0.014 Gomisin A and Gomisin N, respectively. Approximately, 90% of the growth of human stomach adenocarcinoma cancer cells was inhibited after adding 1.0 g/l of the ethanol extract. The growth of the human normal lung cell was limited to 24% after adding the ethanol extract. The water extract lowered the specific secretion of TNF-á and IL-6 from T cells, 10.3×10-4 pg/cell and 12.1×10-4 pg/cell, respectively, compared to the ethanol extracts. On the other hand, a treatment with the ethanol extract increased the specific secretion of TNF-á and IL-6 from human T cells, to 11×10-4 pg/cell and 14.3×10-4 pg/cell, respectively. The crude ethanol extract had the highest effect on the differentiation of human promyelocytic leukemia cells compared to the other extracts and Gomisin A and N. In general, the biological activities of the extracts gradually decreased as the purification process proceeded, which suggests that higher immunostimulatory activities can be maintained by adding the crude extracts of the fruits rather than by adding a single compound.

Two important loci, designated Rhg1 and Rhg4, are responsible for most resistance to soybean cyst nematode (SCN). The objective of this study was to survey single nucleotide polymorphism (SNP) and to map the SCN-resistant gene, Rhg4, on soybean genetic ma

Danok3, a sweet corn hybrid that matures early was developed by the corn breeding team at the National Crop Experiment Station (NCES), RDA in 2001. Inbred KSS2 derived from Golden Bantam was used as the seed parent of Danok3, and inbred KSS22 derived from

Mananbyeo was developed from a three way cross ilyang110/Yeongdeog7//Milyang110 in 1999. It has short growing duration about 71 days from seeding to heading and short culm length of 75 cm. It has almost similar number of panicles per hill , spikelets per

To evaluate the efficiency of anther floating culture according to the maturing group, the varietal difference and classification of fifty varieties was conducted in N6 liquid medium containing 1mg l-1 NAA, 0.25 mg l-1 kinetin. The efficiency of callus induction was widely ranged from 0 to 113.4%, but the mean callus induction was not significantly different among maturing groups. The efficiency of anther floating culture showed the highest variation in early-maturing group among three maturing groups. The varieties with the best callus induction were Sambaegbyeo and Jinbuolbyeo, while the recalcitrant variety was Obongbyeo in early-maturing group. The efficiency of plant regeneration showed the highest trends in late-maturing group among three maturing groups. The fifty varieties were classified into three groups (distance=0.78) by cluster analysis based on the callus formation and plant regeneration. Group including only two varieties, Shinunbongbyeo and Sambaegbyeo had the excellent androgenic efficiency, and the medium efficiency of Group was included thirty-six varieties. Whereas twelve varieties, including three Tongil varieties were fell into the bad efficiency of Group. Especially, Tongil varieties containing Japonica rice, Obongbyeo were the recalcitrant genotypes for the anther floating culture.

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.

Winter green manure crops including legume increase grain yield of subsequent crop and substitute N fertilizer requirement with organic-No Hairy vetch grows vigorously and can provide N-rich green manure for corn with its soil incorporation after wintering. But, grain yield of corn as succeeding crop would be reduced if its planting time is delayed until late spring. This experiment was carried out to find the proper incorporation time of hairy vetch green manure and planting time of subsequent corn in cropping system with winter hairy vetch(green manure)-summer corn. Hairy vetch was incorporated into soil at a ten-day interval between April 10 and May 10 and corn was planted at 5 days after each hairy vetch incorporation. Soil nitrate concentration on April 10 and 20 in hairy vetch plot was slightly lower than that at winter fallow. Above-ground dry matter and organic-N of hairy vetch increased linearly with delayed hairy vetch incorporation time from April 10 to May 10. Average dry matter and organic-N produced by hairy vetch were 5.7 ton/ha and 248 kgN/ha, respectively. Corn growth and yield decreased as delayed corn planting time after May in spite of increasing dry matter and N-yield of hairy vetch. Nitrogen concentration of corn grain, stalk and whole plant at harvest were the highest in May 5 planting, but total N-uptake of May 5 planting were not different from that of April 25 planting because of lower grain yield. It was concluded that the proper incorporation time of hairy vetch and corn planting time were April 20 and April 25, respectively, because grain yield was the highest and corn could use hairy vetch-N effectively to produce dry matter.

The concerns on the crop damage by ultraviolet (UV) radiations is increasing owing to the decrease of their absorbing stratospheric ozone in the tropospheric. Cultivar differences on early growth of UV radiation among five Korean rice cultivars, four japonica types and one Tongil type (indica-japonica cross hybrid), were studied. Pot-seeded rice plants were grown under four different radiation conditions, i.e., visible radiation only, visible radiation with supplemented with high or low dose of UV-B (280~320 nm in wavelength) and UV-C (less than 280 nm in wavelength). The inhibitory degree on plant height, shoot and root weight and length of leaf blade and leaf sheath were determined at 40 days after seeding. UV-C showed the most severe inhibitory effect on the degree of biomass gain and leaf growth in most cultivars examined, followed by high UV-B and low UV-B. Among the cultivars used, the Kuemobyeo was the most sensitive cultivar and had not repair or showed resistance ability to continued irradiation of UV radiation. However, Janganbyeo and Jaekeon showed different responses that the elongation of leaf blades was promoted on 2nd and 3rd leaves and inhibited on 4th and 5th leaves but this inhibitory degree was reduced on 6 th and 7th leaves. Such tendency on leaf growth means that both cultivars had low sensitivity and most resistant ability to continued irradiation of UV radiation. While Tongil showed different response to enhanced UV radiation, ie., low UV-B promoted leaf growth but the inhibitory was severely increased by continued irradiation of high UV-B and UV-C, which means that Tongil had high threshold of UV radiation for response as an inhibitory light of plant growth. The results of this study indicate that the differences on sensitivity or resistant to the effects of UV radiation were existed among Korean rice cultivars