Abstract
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.
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.