http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kyungdeok Noh,Byoung Ryong Jeong 경상대학교 농업생명과학연구원 2022 농업생명과학연구 Vol.56 No.5
The home hydroponic system used in this experiment supplied the nutrient solution using the ebb and flow-type system, and the supply time, interval, and water levels of the nutrient solutions were fixed. This experiment was conducted to find a more favorable growth medium for plant growth in the hydroponic system. The medium used in the experiment was of two types, phenolic foam and rockwool, and the heights were 28 and 38 mm, respectively. As for the the multipurpose nutrient solutions (GNU1 and GNU2) were prepared in the lab. The composition of the GNU1 and GNU2 was the same, and there was a difference between 100 and 70% in ion concentrations. The plants used were Ssamchoo (Brassica lee ssp. namai) and Romaine lettuce (Lactuca sativa L. var. longiflora). First, in the physicochemical measurements of the empty medium, change in the pH and EC of the distilled water passing through the medium was less in the rockwool than in the phenolic foam. This indicates that there is less change in the chemical properties of the nutrient solution due to the medium when rockwool is used. After hydroponic culture of Ssamchoo and Romaine lettuce, the medium showed more residual salts in Romaine lettuce. Both Ssamchoo and Romaine lettuce showed less salt accumulation in rockwool. The emergence rate was significantly higher in rockwool for both species. The lower height of the medium, the faster the emergence was. Ssamchoo displayed significantly higher fresh weight (124.7%), shoot length (107.6%), and leaf width (107.9%) when grown in GNU1, but there were no significant differences as affected by the medium. However, in Romaine lettuce, the type and height of the medium resulted in significant differences. The fresh weight of Romaine lettuce was significantly higher in rockwool (119.6%) than in phenolic foam, and significantly higher at 38 (114.6%) than 28 mm. Although there is a difference depending on the species, rockwool is more suitable for the ebb and flow-type system than phenolic foam, and the height of 38 is more advantageous than 28 mm.
Jinnan Song,Jingli Yang,Jie Xiao,Ge Guo,Kyungdeok Noh,Byoung Ryong Jeong 한국원예학회 2021 한국원예학회 학술발표요지 Vol.2021 No.10
Ammonium (NH₄<SUP>+</SUP>) sensitivity of plants is an issue of agricultural and ecological importance. Excessive NH₄<SUP>+ </SUP>triggers widely-integrated impact, conferring the toxicity symptoms. Despite plant species differ in their NH₄<SUP>+</SUP> toxicity tolerance, current knowledge suggested that all plant species employ an identical pathway in nitrogen (N) uptake and assimilation. This study was conducted to get a new insight toward NH₄<SUP>+</SUP> tolerance in plants that drew comparisons with activities of key enzymes as well as contents of chemicals assessed in this pathway in two popular leafy vegetables, Korean cabbage (Brassica campestris L.) ‘Ssamchu’ and lettuce (Lactuca sativa L.) ‘Caesar green’ as the model plants. When these plants were supplied with one of three ammonium (NH₄<SUP>+</SUP>):nitrate (NO₃<SUP>-</SUP>) ratios, 100:0, 50:50 and 0:100, during a hydroponic cultivation, lettuce was relatively more tolerant, while Korean cabbage was highly sensitive, to NH₄<SUP>+</SUP>. Ammonium sensitivity was characterized by certain detrimental visual symptoms developing on the plant such as reduced plant growth, leaf chlorosis and stunted roots, and also biochemical attributes such as enhanced activities of antioxidant enzymes, decreased contents of starch, sugar and vitamin C, and decreased photosynthesis. Subsequent quantification of activities of key enzymes and contents of chemicals showed remarkably higher contents of nitrite (NO₂<SUP>-</SUP>) and lower activities of nitrite reductase (NIR) in Korean cabbage as compared to lettuce, suggesting that these two parameters may have contributed to the differences in NH₄<SUP>+</SUP> sensitivity of these two plant species.