Eating quality is critical for consumers who take rice as staple food. Here we present the development and identification of high eating quality rice lines. The identification of positive transgenic lines, physicochemical properties of transgenic rice, mRNA expression and enzyme activity were analyzed. OsSbe1 was introduced into Gopumbyeo seeds using Agrobacterium-mediated transformation, and 1,005 out of 1,065 T1 plants were shown positive. The apparent amylose contents in T2 brown rice ranged from 11% to 25% in 890 favorable lines (Gopumbyeo was used as a reference with 18% of AAC). The activity of starch branching enzyme including three isoforms (SBE1, SBE3, and SBE4) in endosperms of T3 lines was higher than that of Gopumbyeo. Physicochemical properties related to eating quality for T3 polished rice were detected using 52 favorable lines out of 500 lines selected according to AAC. The Toyo taste meter value in 52 T3 lines ranged from 61.1 to 72.6, whereas 70.4 in Gopumbyeo. Of them, eleven lines displayed the higher palatability score than Gopumbyeo. Moreover, these elite lines produced higher yields (607.9~695.8 kg/10a) than Gopumbyeo (602.7 kg/10a). These results indicated the possibility of developing new high quality rice varieties in the future.

“Woncheongbyeo” is a new japonica rice (Oryza sativa L.) cultivar developed by mutation techniques from Chu-cheongbyeo. Chucheongbyeo seeds were irradiated with 300 Gy gama ray (83.3 rad/min) emitted from 60Co at a radiation facil-ity of the Korea Atomic

This experiment was carried out on plastic pots (40cm~times25cm~times30cm ) filled with sand soil at greenhouse using two soybean cultivars with small seed; one was Pungsannamulkong (PSNK) recognized as a tolerant cultivar against excessive water stress and the other one was Sobaeknamulkong (SBNK) recognized as a susceptible cultivar. Seed was sown with 30 plants of 2 hills, and the amount of applied fertilizer was N; 3.0 g, P; 3.0 g, and K; 3.4 g per m2 with all basal fertilizations. Plants were grown under photoperiod of natural light with day temperature of 31~pm5~circC and night temperature of 22~pm1~circC . The flooding treatment was done for 3, 5, 7 and 10 days by filling pots with tap water up to 1 cm above the level of the soil surface when plants were 2 days after emerging. Nitrogen uptake by leaves of soybeans decreased significantly by the flooding after 6 days. This significant reduction of N uptake by flooding was evidently recognized from the chlorosis of leaves. The dry matter of flooded soybean seedlings significantly decreased compared to non-flooded soybean seedlings at 10 days. The dry matter of roots also showed similar result of the shoot. Shoots had more N reduction than roots under the flooding. This N reduction was more pronounce in SBNK than in PSNK. Chlorophyll content of flooded soybeans showed decreasing or non-increasing tendency, and the reduction of chlorophyll content was more in SBNK than in PSNK from the flooding stress. Nitrate content of soybean seedlings with flooding stress showed decreasing tendency in shoot and root parts. Ammonium content, however, was higher in flooding stress compared to the non-flooding. Flooding caused a remarkable change in the AA (amino acid) composition and TAA (total amino acid) concentration in the leaves of soybean seedlings.

Field studies were conducted in the southeastern Korea (36~circ N) on a commerce silt loam soil at paddy field. Seed were manually planted on 16 July 2003. Plants were planted with plant densities of 70~times 10 cm (row width x plant spacing), 50 x 10 cm, and 30 ~times 10 cm. Two seedlings per hill were taken prior to V3 stage. Fertilizer was applied prior to plant at a rate of 30-30-34 kg (N-~textrmP2~textrmO5 -~textrmK2~textrmO ) per ha. Experimental design was a randomized complete block in a split plot arrangement with three replications. Yield from different planting densities responded similarly in three soybean cultivars and increased when planting density increased. Somyeongkong showed the highest increasing rate of yield about 26% by 338 g ~textrmm-2 at 30 x l0 cm compared to yield of conventional planting density (70 x 10 cm). Also, the planting density significantly affected pod and seed number and seed weight, but not seed per pod. The tallest plant appeared at 30~times 10 cm. The change of leaf area according to days after emergence showed differently in soybean cultivars. The highest and lowest total dry matter production per square meter appeared at 30 x 10 cm and at 70 x 10 cm, respectively. Crop growth rate (CGR) showed greater at R3∼R4 stages compared with V7∼R2 or R2∼R3 growth stages and showed the greatest at 30 x 10 cm in three soybean cultivars. As late planted soybean, there was a significant relation between seed yield and CGR, and leaf area index (LAI) according to planting densities at before and after the flowering stage. Relationship between seed yield and CGR in three planting densities showed a highly significant positive relation (~textrmR2 =0.757) at R3 to R4 stages, and significant relations (~textrmR2 =0.505, 0.617) at V7 to R2 and V2 to V3. Also, there was a highly significant positive difference between seed yield and LAI during R3 to R4 and R2 to R3 stages.

U.S. EPA의 BASINS (Better Assessment Science Integrating Point and Nonpoint Sources)에 통합되어 있는 HSPF (Hydrologic Simulation Program-Fortran)와 SWAT (Soil and Water Assessment Tool) 모형을 이용하여 Polecat Creek 유역의 유출과 유사량을 모의하였다. 모형의 보정을 위하여 1996년 9월부터 2000년 6월까지의

“Jinpumbyeo” is a new japonica rice cultivar developed from a cross between lodging tolerant semi-dwarf plant type, SR14703-60-5-GH1 and high eating quality cultivar Suweon353 by the rice breeding team of National Crop Experiment Station, RDA made in 1987

The induction of enzymes and the accumulation of their end products associated with self-defense mechanism in rice were investigated. When rice leaves were irradiated with UV light, activities of diterpene cyclase, phenylalanine ammonia-lyase (PAL), and cinnamic acid 4-hydroxylase (CA4H) were induced and rice phytoalexin, momilactone A was accumulated. The content of p-coumaric acid in rice leaves was closely correlated with self-defense or allelopathic potential against barnyardgrass. UV-challenged rice leaves gave rise to the inhibition of barnyardgrass growth