Oil and fatty acid composition of 648 soybean germplasms of different categories including Korean and American source were analyzed by NIRS (Near Infrared Reflectance Spectrophotometer) method at Yeongnam Agricultural Research Institute, Milyang, Korea. A

Three different male-sterile cytoplasmic lines and their common maintainer 'Zhenshan 97B' and two elite restorer lines were used to study cytoplasmic effects on agronomic trait manifestation per se under different nitrogen supply levels. The result showed that cytoplasmic effects could be modified by nitrogen environments. The cytoplasmic effect on grain yield under 150 kg N/ha varied depending on crosses, while it was significantly negative in most crosses under both 60 and 330 kg N/ha. The correlation and path-coefficient analyses suggested that it was expected to improve cytoplasmic effects through reducing maximum tillers and increasing the percentage of productive tillers, leading to increased productive tillers and higher yield in hybrid rice by the aid of cultural practice and genetic transformation. This study also revealed that the same cytoplasm in different combinations had differential effect under the same nitrogen environment, indicating that cytoplasmic effect was produced by interaction of nuclear genes with cytoplasm rather than cytoplasm per se. These results indicated the usefulness of evaluating diverse cytoplasmic sources in various nuclear genotypes bred for hybrid rice breeding program. The finding also suggested that negative cytoplasmic effect could be effectively overcome by elite restorer lines through the interaction of nuclear genes with female cytoplasm.

본 연구는 잡종강세를 나타내는 두 조합의 벼 일대 잡종 품종, Shanyou 63, Teyou 53과 inbred계인 밀양 23호 등을 공시하여 벼의 잡종강세 발현기작을 규명코자 실시되었으며, 수행 후 얻어낸 결과를 요약하면 다음과 같다. 1. 종자 단백질 분석을 통해, 잡종강세 발현의 유전적인 특성들이 부분적으로 모본으로 부터 유전된다는 사실을 규명하였다. 2. Hybrid계 벼는 inbred계보다 배아의 크기가 크고 α -amylase 활성 및 chlorophyll함량이 높게 나타났다. 이러한 특성들은 분얼능력, 특히 수량에 밀접한 영향을 끼치는 하부절간의 분얼수와도 관계가 있었으며, Shanyou 63의 경우 다른 inbred계에 비해 60~70%나 분얼력이 높았다. 3. 인위적으로 GA3 0.02 ppm을 처리한 후 α -amylase활성 측정시, hybrid계에는 영향을 미치지 못하였으나 밀양 23은 무처리보다 높은 활성을 나타내었다. 이와 같은 결과는, hybrid계 벼의 종자내에는 이미 충분한 GA를 함유하고 있으며 이것이 초기활력과 관계있는 것으로 추정된다. 4. Cytochrome c oxidase의 활성은 inbred계 보다 hybrid rice에서 2.7~5.5배나 높게 나타났으며, 따라서 hybrid계 벼의 대사작용이 매우 높았다.