초록
김엽체의 생장에 미치는 식물흐르몬의 영향을 조사하기 위해서 Gibberellin, IAA, Kinetin, NAA및 2.4-D 등을 농도별로 회석한 배지에서 김엽편을 32일간 배양하고 또 2차적으로 Kinetin의 농도별배지에서 수온을 $5^{\circ}C$와 $10^{\circ}C$로 구분하여 18일간 배양하였다. 그 결과를 요약하면 다음과 같다. (1) Gibberellin은 10.0mg/l 농도에서, 기타는 모두 5.0mg/1 농도의 배지에시 각각 최고생장효과가 나타났다. 간종량으로 본 효율치는 Kinetin이 $312.5\%$(엽면체:$345.3\%$)로 으뜸이며 2.4-D는 $257.5\% (236.1\%)$, Gibberellin $247.9\%(241.9\%)$, IAA, $166.7\%(147.6\%)$, NAA $141.7\% (167.7\%)$의 순이였다. (2) 특히 Kinetin 5.0mg/1농도에서 배양된 엽편은 그 색채가 진한 흑갈색으로 가장 좋았으며 세포마다 생기 있는 큰 색소체가 뚜렷하고 건전하여 뛰어난 효과가 나타났으나 기타는 색채가 담갈색 또는 황록갈색으로 변하고 사세포가 많이 발견되었으며 생세포도 원형질이 위축되었거나 큰 세포가 생겨 매우 불건전하였다.(3) 저온($5^{\circ}C$)과 고온($10^{\circ}C$)에서의 Kinetin의 생장효율은 저농도에서는 대차가 없었으나, 5.0mg/1의 고농도애시는 저온이 $366.7\%$, 고온이 $318.8\%$로서 $48\%$의 효율차가 생겼으며 세포의 건전성은 1차시험때와 마찬가지로 모두 좋았다.(4) 최고생장효과가 나타난 Kinetin 5.0mg/1농도에서는 엽편의 녹변에 지름 $25.0\sim27.5\mu$ 정도의 이상대형세포가 많이 발견되었으며 그 중에는 한 세포내에 수개의 색소체가 있는 것이 관찰되었다. 두께도 $41.0\sim42.0\mu$으로 비교적 두꺼웠다.(5) Kinetia 1.0mg/l농도의 배지에서 배양된 엽편중에는 조정기을 형성하고 있는 세포군이 관찰되었다.
As one of the fundamental studies for the breeding of marine algae, the effects of several plant hormones (IAA, Gibberellin, 2.4-D, NAA, Kinetin) on the growth of Porphyra-fronds, P. tenera Kjell. form tamatsuensis Miura, were investigated from January 21 to February 21 1981. The fronds used for the experiment were dissected out at $25mm^2$ size, and cultured in modified Provasoli's ESP medium supplemented with various concentrations of each plant growth regulators. The culture was kept under constant water temperature of $5^{\circ}C$ in 14 hrs. photoperiod and illuminated with 2,400 lux by fluorescent light. Based on the results of first experiment, the culture of fronds for the secondary experiment was carried out at $5^{\circ}C\;and\;10^{\circ}C$ in medium containing various levels of Kinetin from April 6 to 24, and compared the growth of two groups at each concentrations with each other, The results obtained are summarized as follows : (1) The best growth efficiencies were observed at 5.0mg/1 of each plant hormones except Gibberellin. Among them, the highest growth-rate was $312.5\%\;(345.3\%\;in\;frond\;size)$ in contrast with control at 5.0mg/1 of Kinetin, and was followed by $257.5\%\;(236.1\%)$ in 2.4-D,$166.7\%(147.6\%)$ in IAA and $141.7\%\;(167.7\%)$ in NAA, but that in Gibberellin was $247.9\%(241.9\%)$ at 10.0mg/l. (2) Especially, the fronds cultured at 5.0mg/1 of Kinetin were deep black-brown in colour, and had vivid, healthy chloroplasts in their all cells. On the contrary, the fronds cultured in other media were discoloured to light black-brown or green-drown, and almost all cells were vacuolated or shrunk gradually into death.(3) There was an obvious difference between the best growth-rates of the fronds cultured at 5.0mg/l of Kinetin at $5^{\circ}C$ and those at $10^{\circ}C$. The former was $366.7\%$, the latter $318.8\%$ but the difference was little at lower concentrations. (4) Many abnormal cells grown up to $25.0-27.5\mu$ in diameter were found among the marginal cells of fronds which showed the best growth in Kinetin, and the fronds wire $41.0-42.0\mu$ in thickness which was thicker by $10.0\mu$ or so than the others. (5) In two fronds at 1.0mg/1 of Kinetin cell-divisions were observed, which might developed into antheridium, but it was doubtful whether due to the efficiency of Kinetin.