보리 유묘의 염농도에 따른 세포의 형태반응

Cellular Structural Change of Barley Seedling on Different Salt Concentration under Hydroponic Culture

염분농도가 상이한 1/2 Hoagland 수용액에 보리 유식물을 생육시켰을 때 수경액의 염분농도가 높아짐에 따른 몇가지 변화의 양상을 관찰한 결과를 요약하면 다음과 같다. 1. 지상부나 지하부의 생육량은 수경액에 25mM정도 NaCl이 함유된 때에 오히려 많았으나, NaCl 농도가 50mM 이상일 때에는 현저하게 감소하기 시작했다. 2. 식물체내의 수분함량은 수경액의 NaCl농도가 높아질수록 낮아져 염생식물과는 달리 식물체내에 있는 NaCl이 삼투압 조절물질로 작용하지는 않았다. 3. 수경액의 NaCl의 농도가 높아짐에 따라 초엽에 있어서 단위 면적당($cm^2$) 기공의 수는 많았으나(무처리;3,683, 100mM NaCl처리;5,153) 길이가 짧아져 약간씩 감소하였다. 4. 뿌리의 생장점은 수경액의 NaCl 농도가 75mM 이상인 경우에 핵분열이 심하게 저해되었다. 5. 수경액의 ,NaCl 농도가 75mM 이하의 경우 엽록체는 NaCl에 의해 stress를 받지 않아 형태적인 면에서 변화가 없었으나 근단 생장점의 Mitochondria가 파괴되는 현상을 볼 수 있었고 NaCl 75mM구에서 불규칙한 고형물질이 세포벽쪽에 밀집한 것을 관찰할 수 있었다.

The salt stress at seedling stage of winter barley was examined in different concentrations of NaCl containing 1/2 Hoagland solution. Fresh weight of seedling at 30 days after seeding was highest at 25mM of NaCl concentration containing 1/2 Hoagland solution but if the NaCl concentration was more than 50mM it began to decrease seriously. Water content in plant was decreased according to increase of NaCl concentration in 1/2 Hoagland solution, so physiological mechanism of NaCl in barley was different from saline plant. Stoma number per cm$^2$ of first leaf was higher than that of control in case of stressed by NaCl but in that case the leaf length was decreased so the number of stoma per first leaf was slightly decreased. Chloroplast shape was not changed by 75mM of high NaCl contained 1/2 Hoagland solution but cell division at root growing point was inhibited by 75mM of NaCl. As the result of salt stress mitochondria was ruined in structure and irregular solid was found to be transfered from the cytoplasm to the cell wall in root growing point.