Physiological Response of Winter Barley to Salt Stress at Seedling Stage

보리 유묘기의 염처리가 생리적 반응에 미치는 영향

Some physiological characteristics and cultivar differences of winter barley to salt stress were studied during seedling stage. Salt stress was caused by adding NaCl solution to the pot culture soil. Measurements of the responses to salt stress and of the responses after relief from stress were done in terms of leaf water potential, chlorophyll and free proline contents, seedling height and seedling dry weight, and survival rate of leaves. Under salt stress ($\Psi_{\pi}$ =-20bar) seedling height and seedling weight were decreased by 2~22% and by 25~39% respectively, showing some differences among cultivars. Chlorophyll contents was decreased by 33~49%, and free proline content was remarkably increased from control 0.2~0.3mg to salt stress 9.6~14.7mg. The leaf water potential of seedling grown under salt stress with NaCl solution($\Psi_{\pi}$ =-10 or -20bar) was decreased from control -3.3bar to salt stress -9.0bar or -16.2bar respectively but there were no large differences among cultivars with time after relief from salt stress. Leaf survival rate was high in order of Baegdong, Milyang12, Olbori, Durubori and Hyangmaeg, and decrease rate of seedling dry weight was low in the order of Baegdong, Olbori, Hyangmaeg, Milyang12, Durubori. The increase in free proline contents was high in the order of Milyang12, Hyangmaeg, Baegdong, Durubori and Olbori.

보리 품종들의 염해반응의 생리적 특성과 품종간 차이를 이해하여 간척지에서의 재배법 개선을 위한 기초자료로 활용코자 NaCl용액으로 염해를 유발하여 생장저해정도, 엽록소 및 유리 proline 함량, 그리고 엽수분 potential 등을 조사하였던 바 그 결과를 보면 다음과 같다. 1. 품종간 생육저해 정도는 상당히 큰 차이를 보였는데 대조구에 비해 NaCl용액(Ψ/sub π/ =-20bar) 처리의 경우 초장은 2∼22％, 유묘건물중은 25∼39％가 감소되었다. 2. 엽록소함량은 대조구에 대하여 염분처리구에서 33∼49％ 감소되었고 엽건물 g당 유리 proline 함량은 대조구가 0.2∼0.3mg이나 염분처리 구는 9.6∼14.7mg으로 32∼74％나 증가되었다. 3. 엽수분 potential은 대조구가 -3.0 ∼ -4.1bar이나 염분처리구에서는 -7.4 ∼ -11.2bar와 -15.0 ∼ -17.9bar로 낮아졌으나 시간의 경과함에 따라 품종간 차이는 많지는 않았다. 4. 품종별로 엽생존율은 백동>밀양1002>올보리>두루보리>향맥의 순으로 높았으나 유묘 건물중 감소율은 백동>올보리>향맥>밀양1002>두루보리 순이었다. 5. 염처리구에서 제2엽의 유리 proline 증가율은 밀양1002>향맥>백동>두루보리>올보리의 순이 었다.