맥류의 한발저항성 반응과 정도 그리고 저항생리적 기작을 구명하기 위하여 발아후 10일된 유묘기(본엽 3매시)에 8일간 단수처리를 하여 질산환원효소와 단백질분해효소의 활성변화 그리고 proline축적을 조사하였던 바 그 결과는 다음과 같다. 1. 전품종의 평균 감소율은 질산환원효소의 활성이 42%이였으며 단백질분해효소의 활성은 73%였으며, 이에 반하여 proline은 대조구에 비하여 단수구가 무려 10배나 증가하였다. 2. 질산환원효소의 활성감소율을 맥종별로 보면 소맥 < 호맥 < 대맥 < 2조대맥ㆍ과맥의 순으로 소맥이 가장 낮았다. 3. 단백질분해효소의 활성감소율을 맥종별로 보면 소맥 < 호맥 < 이조대맥 < 대맥 < 과맥의 순으로 소맥이 높고 과맥이 가장 낮았다. 4. 단수구의 proline의 축적색대량을 맥종별로 보면 소맥 < 대맥 < 호맥 < 과맥 < 이조대맥의 순으로 소맥과 대맥이 높았으며, 대조구에 대한 단수구의 증가비는 호맥(13배) > 소맥ㆍ대맥(11배) > 과맥(9배) > 이조대맥(7배)의 순으로 호맥이 가장 높았다. 5. 한발저항성 과정에서 효소적 및 생리적 대사작용의 관점에서 볼 때 소맥 > 호맥 > 대맥 > 과맥 > 이조대맥의 순으로 한발저항성이 강한 것으로 추정된다.

In order to observe the degree and response of drought-resistance and its physiological mechanism in barley and wheat seedling stage, 5 species (16 cultivars) were tested for the changes of nitrate reductase and protease activity and the accumulation of free proline, by being subjected to water stress by withholding watering for 8 days at 10 days (at the 3rd leaf stage) after emergence and by imposing water stress to the excised first leaf by polyethyleneglycol solution (osmotic potential, -20 bars) for 48 hours. The average rate of decrease of all cultivars was 42% in nitrate reductase activity and 73% in protease activity. But proline content in water stress was increased 10 folds more than that of control. The decrease4 rate of nitrate reductase activity in 5 species was in the order of wheat < rye < covered barley < naked barley < two-row barley: wheat being the lowest. The decreased rate of protease activity in 5 species was in the order of wheat > rye > two-row barley > covered barley > naked barley: wheat being the" heighest. The accumulated amount of free proline in 5 species by water stress was in the order of wheat > covered barley > rye > naked barley > two-row barley. And the increased ratio (folds) of free proline of water stress to control was in the order of rye(13) > wheat. covered barley(11) > naked barley(99) > two-row barley(7): rye being the highest. In terms of the enzymatic activity and the physiotically adaptive metabolism during the processing leading to drought-resistance, the degree of drought-resistance of 5 species to water stress at seedling stage was shown to be in the order of wheat > rye > covered barley > naked barley > two-row barley.

• 崔元烈(전남대학교 농과대학 농학과) | 최원열
• 閔庚洙(전남대학교 농과대학 농학과) | 민경수