벼의 질소시비량 및 수확시기에 변화에 따른 도정특성 및 쌀 품질변화를 구명하기 위하여 일품벼와 추청벼를 시험품종으로 질소시비량과 수확시기를 다르게 하여서 시험하였다. 질소시비량은 무처리를 대조구로 하여 5 kg, 9 kg, 13 kg, 17 kg, 21 kg/10a의 5수준으로 하였고 질소시비방법은 기비-분얼비-수비를 5:2:3으로 분시하였으며, 인산과 칼리의 시비량 및 시비방법은 표준재배법에 준하여 실시하였다.수확시기는 출수 후40일, 50일, 60일, 70일, 80일로 하였다. 두 품종 모두 질소시비량과 수확시기가 달라짐에 따라 도정률에 큰 변화가 없었다. 그렇지만 질소시비량은 정현비율과 정의 상관관계를 나타내었지만 현백비율과는 부의 상관관계를 나타내었다. 품종간에는 추청벼가 일품벼보다 평균적으로 모든 시비 수준에서 높은 도정률을 나타내었다. 질소시비량과 완전미율은 부의 상관관계를 나타내었다. 품종간에는 13 kg/10a 이하의 시비수준에서는 추청벼가 일품벼보다 높은 완전미율을 나타내었지만 그보다 높은 수준에서는 일품벼가 추청벼보다 약간 높았다. 두 품종 모두 질소시비량이 증가할수록 분상질미와 싸라기 발생은 높아지는 경향이었다. 질소시비량과 수확시기에 따른 쌀의 단백질함량 변화는 질소시비량이 증가할수록 단백질함량 또한 증가하였으나 수확시기에 따라서는 차이가 없었다.

KNU corn breeding team in collaboration with International Corn Foundation (ICF) is dedicated to develop super corn hybrids for developing countries like Nepal and Cambodia. The team works to develop high bio-energy maize hybrids for Korea. Crossing of temperate with tropical germplasm shows new heterotic patterns. Four tropical inbred lines from IITA, Nigeria, ten sub-tropical lines from Nepal and two temperate lines (P45 and 69B) from Korea were crossed to produce single-cross hybrids. Besides, four single-cross hybrids from Nepalwere crossed with P45 and 69B to produce three-way crosses. Gray leaf spot (Cercospora zea-maydis) being the most important problem of corn in mid-hills of Nepal, GLS resistant materials from IITA were crossed with Nepal materials in Cambodia to produce GLS tolerant hybrids. Single-cross hybrids were evaluated at ICF Agriculture Center in Cambodia and KNU farm, Gunwi in Korea in 2008. The three-way crosses were planted at Gunwi farm and the GLS resistant materials were planted at Khumaltar station of Nepal Agricultural Research Council, Kathmandu. Crosses of Tzi-25 with RML-4 and RL-111 and RL-105xNML-2 were found outstanding in Cambodia. Four tropical x subtropical hybrids (Tzi-18xRML-4, Tzi-18xRL-14, Tzi-25xRL-14 and RL-47xTzi-25), four temperate x subtropical hybrids (P45xRL-111, P45xRML-8, RML-5x69B and 69BxRL-105). P45xGaurab was the most suitable for both grain and biomass production.

Agricultural productivity is subjected to enormous environmental constraints, particularly to salinity and drought due to their higher magnitude of adverse impacts and worldwide distribution. Silicon (Si) was found to play a favorable role in salinity and drought stress alleviation of soybean cultivar Daewonkong. All growth attributes insignificantly improved with Si nutrition. The endogenous bioactive GA1 and GA4 content increased with the application of elevated Si level both under normal and stressful condition. JA contents sharply increased with NaCl and PEG application but decreses with Si added to salt and drought stress treatments. SA level increased with NaCl and PEG and was further enhanced with Si in the salt treated plants, but reduced with the combined application of Si and PEG. The endogenous bioactive GA1 and GA4, JA and ABA content of soybean leaves were analyzed through chromatograph/mass spectrometer (GC/MS) in selected ion monitoring (SIM) mode, while SA content was quantified with HPLC.

This study was carried out to compare the growth and yield characteristics between bakanae diseases (Gibberella fujikuroi) infected and normal rice plants. The infected rice seeds, harvested in last year, were disinfected by prochloraz for 48 hours at 33℃ using sprouting machine, 24 hours at room temperature and not disinfected. In the methods of disinfection, it is more effective in disinfected by prochloraz for 48 hours at 33℃ using sprouting machine near to 0% of infection rate, followed by conventional method as 5.0% and 76% in not disinfected rice seeds. In the rice yield components among the disinfection methods, panicles were increased about 11% in the disinfected seeds using sprouting machine for 48 hours compared to conventional method. Ripening grain rate also increased at the disinfected using sprouting machine as 80.3~80.3%, improved more than 4.9~5.9% comparing to the conventional disinfection. From these results, the rice yield was 512~517kg/1,000㎡ at the disinfected using sprouting machine which increased more than 6~7% compared to the conventional disinfection.

This study was conducted to identify the varietal differences of the viviparous germination and viviparous germinated seed characteristics occurred by continuous rain during maturing stage of rice in 2007. The viviparous germination rates were increased in early and medium-maturing cultivars such as Unkwangbyeo and Gopumbyeo. In the germinating rates using already viviparous germinated seeds were severely deteriorated by 15.3 and 28.2% compared to those of normal seeds as 97.3 and 98.5% on Unkwangbyeo and Gopumbyeo. The regermination rates were increased as the plumule length of already viviparous germinated seeds was shorter, so it is 46.7% in less than 0.9mm plumule length and 12.7% in 1.0~1.9mm.

In rice, tillering is an important trait determining yield. To study tillering at the agricultural and molecular aspects, we have examined a spontaneous rice mutant that showed reduction in the number of culms. The mutant was derived from a F6 line of the cross of Junambyeo*4 / IR72. It could produce, on average, 4 tillers per hill in the paddy field while wild-type plants usually have 15. Except the reduced culm numbers, they also show pale green phenotypes. The phenotypes of this mutant were co-segregated as the monogenic Mendelian ratio (χ2 = 0.002, p = 0.969). In order to locate a gene responsible for the rcn phenotype, the mutant with the japonica genetic background was crossed with Milyang21 of the indica background. Bulked segregant analysis was used for rapid determination of chromosomal location. Three SSR markers (RM551, RM8213, and RM16467) on chromosome 4 were genetically associated with the mutant phenotype. Each of the 217 F2 plants was genotyped with simple sequence length polymorphisms. The data showed that RM16572 on chromosome 4 was the closest marker that showed perfect co-segregation among the F2 population. We suggest the new rcn gene studied here name as rcn10t because there was no report which exhibit a rcn phenotype with a pleiotropic effect of pale green (chlorophyll deficiency), and mapped at same position on chromosome 4.

The germplasm of 246 rice cultivars was analysed 　for iron and zinc contents using a Inductively Coupled Argon Plasma (ICP) at International Rice Research Institute (IRRI) Philippines. Iron contents ranged from 2.0 to 12.0, and zinc ranged from 10.0 to 33.0 (mg/kg), showing with the mean values of 4.3 and 22.8 (mg/kg), respectively. In genotypes tested, there was approximately a two-fold difference in iron and zinc concentrations, suggesting a genetic potential to increase these micronutrients in rice grain. A highly significant positive correlation (r2=0.503) was found between iron and zinc contents. Iron contents decreased drastically as polishing time increased, whereas zinc decreased only slightly. In the interaction between genotype and environment on iron contents, genotype (G), environment (E), and the G × E interactions accounted for 69%, 5% and 26% of the sums of squares, respectively. Indicating that genotype is would be the most significant factor for the to improve iron contents of rice in rice breeding, suggesting that therefore identifying genotypes with relatively stable performance across various environments is important as staple food crops.

We have proposed modeling methods of mariners' standard behavior for collision avoidance by analyzing mariners' recognition process in a previous study. As a subsequent study, the aim of this study is to build a model of mariners' execution process which is one of six processes in the condition of collision avoidance. In this study, thus, the structure of mariners' information processing on the process of taking avoiding actions is described and the relation between mariners' behavior and necessary factors in the process is analyzed. And then we have built a model of mariners' standard behavior for execution process based on the characteristics of mariners in ship-handling, which are obtained from the international collaborative research on human factors. It is tried to define the contents of execution process based on the standard behavior of mariners for collision avoidance and to formulate information processing of mariners.

The aquatic fern Azolla spp. is of value as a bio-fertilizer for wetland paddy. It is popular and cultivated widely in other countries like China, Vietnam, and the Philippines, but has yet to be taken up in Korea, in a big way. It fixes nitrogen as high as 3-5kg N per day, because it contains nitrogen fixing blue-green algae, Anabaena azollae. Azolla's ability to create a light-proof mat that suppresses other weeds has been used for centuries in rice production. Azolla spp. has also the capacity to take up the heavy metals such as Mercury and Chromium (75~100%) and may be used as a bioaccumulator in the phytoremediation. Azolla meal also can be used as an unconventional feed resource has a potential as a feedstuff for livestock.

This experiments were carried out to find out the effects of different explant materials, kinds and concentration of plant growth regulators, and total nitrogen and sucrose contents on the in vitro regeneration of Abeliophyllum distichum Nakai. The effects of growth regulators on regeneration from 3 explant sources (leaf, internode and node) were more or less same. Leaf explants produced only callus with 2ip (Isopentenyladenine) and NAA (Naphthaleneacetic acid) treatment and other regulators had no effects. Test with internode explants yielded about same results but callus was obtained with 2,4-D (2,4-Dichlorophenoxyacetic acid). Node explants resulted in shoot regeneration by all regulator treatment except NAA and 2,4-D, but control also showed similar results. Callus formation from internode and node explants was vigorous by 2ip, zeatin, and 2,4-D treatments and high NAA concentration resulted in higher callus formation. In this experiment, various mixed treatment of growth regulators were also employed, using node as explant material. Shoot regeneration was obtained with BA (Benzyl adenine) + NAA treatments but the results were comparable with control. Generally shoot and root regeneration was poor with all combined treatment except 2ip + NAA and 2,4-D + NAA. However, callus was formed readily with all treatments. In this experiment, combined treatments of regulators were applied on the callus derived from singular regulator treatment. The results showed no shoot and root regeneration with any combination of 2,4-D, IAA (Indoleacetic acid) and NAA, but soft milky white callus was formed in all the treatments. No shoot and root regeneration was observed with any combination of 2iP, NAA and IAA, but somewhat hard, light green callus was formed in all the treatments. Callus formation decreased with high kinetin concentration in case of kinetin + NAA treatment. The experiments with total nitrogen content of media showed that low concentrations of 15 and 30mM were effective for the shoot and root regeneration. Sucrose experiment demonstrated shoot regeneration with 1~4% concentration, and root and callus formation with 2~4%. No root and callus formation was observed with 0 and 1% sucrose.