Nitrogen (N) fertilization is essential for alleviating nutrient deficiencies of the world’s population by increasing rice production, one of the most important food crops of our time. Here we established an in vivo hydroponics rice seedling culture system to investigate the physio-biochemical and molecular responses of various rice genotypes to low nitrogen application. Yoshida’s nutrient solution (YS) was used to grow rice seedlings, and at three-week-old the seedlings manifested highly stable and reproducible symptoms, such as reduced shoot growth and length. Out of 12 genetically selected or tested genotypes, almost all (11 genotypes) showed varied degrees of growth reduction response to applied nitrogen (4 and 40 ppm N for treatment and control, respectively), but SR19663-B-B-34-3-3-3-1 showed similar growth as the control though its leaf width was smaller than the control. The leaves of a 11 representative low nitrogen-responsive genotype as BG90-2 were sampled for revealing the protein profiles between low and normal (control) nitrogen application by using two-dimensional gel electrophoresis (2-DGE) followed by staining of separated proteins with silver. Fifty differentially expressed silver stained protein spots were excised from 2-D gels and 41 proteins identified using high-throughput mass spectrometry (MS) using matrix-assisted laser desorption/ionization-time of flight-MS and nano electrospray ionization liquid chromatography tandem MS. These proteins could be assigned as major (energy metabolism, photosynthesis and oxidative stress) and minor functional categories, revealing many novel low N-responsive proteins, including those having energy/photosynthesis, and defense/stress, and iron homeostasis-related functions.

We study on the dynamic interaction with a simulated physical-biological coupled model response to nutrient reduction scenario in Jinhae Bay. According to the low relative errors, high regression coefficients of COD and DIN, and realistic distribution in comparison to the observation, our coupled model could be applicable for assessing the marine ecosystem response to nutrient input reduction in Jinhae Bay. Due to the new construction and expansion of sewage treatment plant from our government, we reduce 50% nutrient inputs near Masan Bay and sewage treatment plant. COD achieves Level Ⅱ in Korea standard of the water quality from the middle of the Masan Bay to all around Jinhae Bay except the inner Masan Bay remaining at Level Ⅲ. When our experiment reduces 50% nutrient inputs near Masan Bay and Dukdong sewage treatment plant simultaneously, COD decreases to about 0.1-1.2 mg/L (128°30’~128°40’ E , 35°05’~35°11’ N). The COD from the middle of the Masan Bay to Jinhae Bay achieves Level Ⅱ.

“Chensu”, a new oriental squash variety was developed by the National Horticultural Research Institute. An interspecific hybridization was made between “Jecheonjaeae,” the local variety of C. moschata and C. martinezii resistant to powdery mildew in 1991.

“Mansu”, a new oriental squash variety was developed by the National Horticultural Research Institute. An interspecific hybridization was made between “Jecheonjaerae”, the local variety of Cucurbita moschata and C. martinezii resistant to powdery mildew i

Seeds of medicinal soybean [Glycine max(L.) Merill] are characterized by a black seed coat, white stripe at hilum border, yellow cotyledon, and very small seed weight. Production of this medicinal soybean has recently increased as a consumption increased. The objective of this study was to evaluate the growth characteristics and seed yield of collected medicinal soybeans and to obtain basic information on production practices and breeding materials. The collected medicinal soybean lines were cultivated at three locations for two years. Twenty-seven lines were planted at the Research Farm, Korea University, Namyangju city, on May 23, and at the Research Farm, Kyungpook National University, Taegu, on May 20, 1995. In 1996 field experiments, forty-four lines were planted on May 25, at Research Farm, Korea University, and twenty-seven lines among those were planted on June 7 at the Research Farm of National Yeongnam Agricultural Experiment Station, Milyang city. The investigated lines had purple or white flower. Flowering and maturing dates were similar or later than those of the control cultivars. Branch number was greater for the investigated lines. One hundred-seed weight of the lines ranged from 8.5 to 15.0 g. Mean seed yields ranged from 1.54 to 2.89 MT/ha. Nine lines of the investigated medicinal soybeans showed higher yield capacity than the control cultivars. Further research should be done on the improvement of the production system and breeding program of medicinal soybeans.