Characteristics in wilting and transpiration of Panax ginseng leaves

인삼(人蔘)잎의 위조(萎凋)와 증산특성(蒸散特性)

Wilting and transpiration charactistics of Panax ginseng leaves were investigated at two temperature levels. Water potential and water absorption characteristics of leaf segments were also observed. Soybean leaves were compared. 1. Ginseng leaves were thiner, higher in water content and lower in dehydration rate. But time required to reach permanent wilting point (pwp) was less than half of that of soybean leaves because water content at pwp was about two times higher (80% of initial water for ginseng and 50% for soybean leaves). The time was shorter under high air temperature. 2. Transpiration rate was about a quater of soybean leaves and lower at $33^{\circ}C$ than $23^{\circ}C$, indicating that ginseng leaves are less tolorant to high air temperature. 3. Ginseng leaf segment showed smaller water free space but greater water deficit and little difference in was absorption rate. 4. Water potential of leaves measured by liquid immersion method was lower than that of soybean leaves. 5. Above results strongly suggest that ginseng plants are more susceptible to water stress. Thus greater light intensity during leaf growing stage (April to June) is recommendable to increase stomate frequency resulting greater transpiration rate and high temperature tolerance during July and August. Abundant water around roots seems to be beneficial as long as oxygen is not limited in rhizosphere.

대두엽(大豆葉)과 비교(比較)하여 인삼절제엽(人蔘切除葉)의 위조(萎凋) 증산(蒸散) 특성(特性)을 온도별로 그리고 엽절편(葉切片)의 water potential 및 흡수특성(吸水特性)을 조사(調査)하였다. 1. 인삼엽(人蔘葉)은 대두엽(大豆葉)에 비(比)하여 얇고 초기수분함량(初期水分含量)이 크지만 탈수속도(脫水速度)는 적으면서도 영구위조점(永久萎凋点)의 수분함량(水分含量)이 높아서 (초기수분함량(初期水分含量)의 약(約) 80%, 대두(大豆)는 50%) 영구위조점(永久萎凋点)에 이르는 시간(時間)이 대두(大豆)의 반(半)에 불과(不過)하며 고온에서 더욱 단축(短縮)되었다. 2. 인삼엽(人蔘葉)은 대두엽(大豆葉)보다 증산량(蒸散量)이 적었으며 (약(約)1/4) $23^{\circ}C$보다 $33^{\circ}C$의 증산량(蒸散量)이 적어 고온에 대한 내성(耐性)이 적은 것으로 나타났다. 3. 인삼엽(人蔘葉)은 water free space가 적으나 흡수속도(吸水速度)는 (시간당 단위생중당 흡수량(吸水量)) 큰 차이(差異)가 없었고 수분결차(水分缺差)가 컸다. 4. 액침법(液浸法)에 의한 water potential은 대두엽(大豆葉)보다 컸다. 5. 이상(以上)의 결과(結果)는 인삼(人蔘)이 대두(大豆)에 비하여 수분부족(水分不足)에 약(弱)한 것을 나타내며 여름 고온에 의한 위조피해(萎凋被害)가 클 것으로 보였으며 전엽기간(展葉期間)에 수광량(受光量)을 높이고 비교적(比較的) 온도를 높게 경과하여 기공수를 증대시키어 증발산기능을 증대시켜 고온 내성(耐性)으로 키워야 하며 근권(根圈)엔 산소(酸素)가 부족(不足)되지 않는 한 수분(水分)을 충분(充分)히 공급(供給)하는 것이 좋을 것으로 보였다.