Studies on the Drought-Resistance of Major Food Crops I. Effect of Water Stress on the Plant Height, Seedling Dry Weight, Relative Turgidity, Protein and Reducing Sugar in Barley and Wheat Seedling Stage

주요작물의 한발저항성에 관한 연구 제1보 맥류 유묘기의 수분부족이 초장, 유묘건물종, 엽침소, 상대팽압도, 단백질 및 환원당에 미치는 영향

In order to observe the degree and response of drought-resistance and its physiological mechanism in barley and wheat, 5 species (16 cultivars) were tested for changes in plant height, seedling dry weight, chlorophyll content, leaf relative turgidity, soluble protein, reducing sugar and growth of seedling subjected to water stress by withholding watering for 8 days at 10 days (at the 3rd leaf stage) after emergence. The average rate of decrease of all cultivars was 15% in plant height, 24% in seedling dry weight, 32% in chlorophyll content, 27% in leaf relative turgidity, and 27% in protein. But reducing sugar content of control was increased 4 folds more than that of water stress. In the decreased rate of seedling dry weight of each cultivar, rye was shown to be lowest rate, and Baegdong, Mokpo #55, and 3 two-row barley were shown to be the highest rate. The degree of the decreased rate in 5 species was in the order of rye < < wheat < covered barley < naked barley < two-row barley. in the decreased rate of chlorophyll content, rye, Cheonggaemil and Olmil are the lowest group, and the highest one are Milyang #12, Bangsa #6, Hyangmaeg and Sacheon #4. In the decreased rate of leaf relative turgidity, the lowest group (22-25%) were rye, Cheonggaemil and Dongbori #1, and, on the other hand, the highest group (30-33%) were Baegdong and 3 two-row barley. In the decreased rate of soulble protein, the lowest group (14-17%) were Chogwang, Geurumil, Dongbori #1, and Mokpo #55, and the highest one was 3 two-row barley. The increased ratio of reducing sugar of water stress to control was 4 to 5 folds in rye and wheat, and about 2 folds in naked barley and 3 two-row barley. The degree of the increased ratio of 5 species was in the order of rye > wheat > covered barley > naked barley > two-row barley. In terms of the physiological and 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 rye > wheat > covered barley > naked barley > two-row-barley.

맥류의 한발저항성 반응과 정도 그리고 생리학적 기작을 구명하기 위하여 발아 후 10일된 맥류 유묘기(본엽3매시)에 8일간 단수처리하여 초장 유묘건물중 엽녹소 상대팽압도 단백질 환원당의 변화를 조사분석하였던 바 그 결과는 다음과 같다. 1. 전품종의 평균 감소율은 초장 14%, 유묘건물중 24%, 엽녹소 31%, 엽상대팽엽도 27%, 단백질 28%였으며 유일하게 환원당만은 대조구에 비하여 단수구가 4배나 증가하였다. 2. 유묘건물중 감소율을 품종별로 보면 호맥이 가장 낮고, 백동, 목포5005, 이조대맥이 가장 높았으며 또한 맥종별로는 호맥<소맥<대맥<라맥<이조대맥의 순이었다. 3. 엽녹소의 감소율이 가장 낮은 품종은 호맥, 청계밀, 을밀이었고 가장 높은 것은 밀양1002, 방사006, 향맥, 사천004였다. 4. 엽상대팽엽도의 감소율이 가장 낮은 품종(22-25%)은 호맥, 청계밀, 동보리 001였고 가장 높은것(30-33%)은 백동과 이조대맥이었다. 맥종별로 보면 호맥<소맥<라맥<대맥ㆍ이조대맥의 순이었다. 5. 단백질의 감소율을 보면 후광, 그루밀, 동보리 001, 목포5005가 가장 낮은 품종(14～17%)들 이었고 이조대맥이(40%) 가장 심하였으며 맥종별로 보면 소맥<호맥ㆍ대맥<근맥<이조대맥의 순이었다. 6. 환원당의 증가비는 호맥과 소맥이 4～5배였고 이맥과 이조대맥이 약 2배 증가되었다. 맥종별 증가를 보면 호맥<소맥<대맥<라맥<이조대맥의 순이었다. 7 한발저항성 과정에서 생리적 대사작용의 관점에서 볼 때 호맥<소맥<대맥<라맥<이조대맥의 순으로 한발저항성이 강한 것으로 추정된다.