• Ocean and Polar Research
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• 제38권1호
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• pp.47-57
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• 2016

Effects of environmental factors on the zoospore release and germling growth of Chaetomorpha linum were examined. Zoospore release and germling growth experiments were carried out under a combination of temperatures ${\times}$ irradiances, and a single factor of irradiances, salinities, daylength and nutrients (nitrogen, phosphorus). Zoospore release was maximal under condition of $20^{\circ}C{\times}100{\mu}mol\;photons\;m^{-2}s^{-1}$ in a factorial experiment (temperatures ${\times}$ irradiances), at $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in irradiance experiment and at 34 psu in salinity conditions. After 24 days in culture, germling growth was maximal at $25^{\circ}C{\times}100{\mu}mol\;photons\;m^{-2}s^{-1}$ in temperatures ${\times}$ irradiances and at normal seawater (34 psu) in salinity. Germling growth is faster at higher irradiance under same temperature condition and it increased with increasing daylengths (8-16 h). Chaetomorpha linum grew in wide range of N and P concentrations. The growth of germling was maximal at $50{\mu}M\;{PO_4}^{3-}$ and $40{\mu}M\;{NH_4}^+$. Germling growth was more effective under nitrogen addition than phosphorus addition in culture. In conclusion, optimal environmental conditions for zoospore release were $20^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, and 34 psu. In addition, the optimal germling growth was observed at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, 34 psu, 16 h, $50{\mu}M\;({PO_4}^{3-})$ and $40{\mu}M\;{(NH_4}^+)$.

• 한국수산과학회지
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• 제50권2호
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• pp.175-182
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• 2017

We examined the effects of environmental factors on zoospore release and germling growth of the green tide alga Cladophora albida under various conditions of temperature${\times}$irradiance (zoospore release), temperature${\times}$irradiance${\times}$ nutrient (germling growth), and a single factor test of salinity. Zoospore release was maximized at $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$ in the temperature irradiance experiment and at 34 psu in the salinity experiment. Maximum germling growth was observed at $25^{\circ}C$ with $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and PES (Provasoli's Enriched Seawater) in the temperature irradiance nutrient experiment, and at 34 psu in the salinity experiment. Germlings grew faster at higher irradiances for a given temperature level, and also grew faster as salinity increased over the range of 5-34 psu. Overall, optimal environmental conditions for zoospore release were $30^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$ and 34 psu. Maximal germling growth occurred at $25^{\circ}C$, $100{\mu}mol\;photons\;m^{-2}s^{-1}$, PES, and 34 psu. C. albida blooms are most likely to occur under these optimal environmental conditions, as plentiful zoospore release and rapid germling growth lead to population growth.

• 한국수산과학회지
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• 제37권1호
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• pp.57-64
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• 2004

Effects of light and temperature on the nitrate uptake and germling growth of Enteromorpha compressa (L.) Greville (Chlorophyta) were studied based on samples from Cheongsapo near Busan, Korea. In addition, their effects on fatty acids composition in thallus were examined. Nitrate uptake showed saturation kinetics. $V_{max}$ (maximal uptake rate) and its $K_s$ (half-saturation constant) at $20^{\circ}C,\;80\;{\mu}mol\;m^{-2}s^{-1},$ white light were $1.571\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}$ and 3.56 ${\mu}M$, respectively. In nitrate uptake with irradiance, wavelength and temperature, its rate represented respectively the highest value as $1.405\pm0.020,\;0.623\pm0.040,\;1.422\pm0.022\;{\mu}mol{\cdot}g\;fr\;wt^{-1}{\cdot}h^{-1}\;at\;100\;{\mu}mol\;m^{-2}s^{-1},$ red light, $20^{\circ}C$ and exhibited significant difference among the examined conditions (p<0.001). Germling growth of E. compressa also showed saturation kinetics, and $V_{max}$ and its $K_s$ value at $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},$ 12:12 h were $56.18\%\;day^{-1}$ and 0.33 ${\mu}M$, respectively. SGR (specific growth rate) recorded a maximal value as 49.33-54.80, 39.07-50.72, $47.20-54.53\%\;dat^{-1}$ at $120\;{\mu}mol\;m^{-2}s^{-1},$ blue light and $18^{\circ}C$ respectively, and showed significant difference (p<0.001). Red light made the effective nitrate uptake, but germling growth was largely limited by the light. In fatty acids analysis, PUFAs (polyunsaturated fatty acids) were high at blue light, $18^{\circ}C,\;100\;{\mu}M\;NO_3^-.$ However, irradiance did not affect the production of PUFAs. In conclusion, nitrate uptake and germling growth of E. compressa showed saturation kinetics to external nitrate concentration, and were significantly affected by irradiance, wave length and temperature. Fatty acid composition was also influenced by the factors except for irradiance. Their maximal values, together with the highest production of PUFAs, were found at blue light band, $20^{\circ}C,\;100\;{\mu}mol\;m^{-2}s^{-1},\;and\;100\;{\mu}M\;NO_3^-.$

• Animal cells and systems
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• 제7권4호
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• pp.295-301
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• 2003

Effects of the settlement density of germlings and canopy on settled germlings of Fucus serratus were investigated on the rocky shore of the Isle of Man. The survival of transplanted germlings was mainly determined by parent canopy rather than by initial settlement density of germlings. However, germling growth was greater at low density than at high density and enhanced by canopy removal. Recruitment by natural propagules was stimulated at high settlement density and maximal recruits occurred on caged slides under the canopy. On the experimental slides, tiny snails and sedimentation were ,found. The number of snails was positively related with the settlement density of germ lings indicating that they fed the germlings. Sedimentation and snail number were greater with canopy removal treatments than in canopy intact ones. These indicate that ,canopy sweeping gives benefits to germlings by removing sediment from substrata and protecting them from herbivores. In conclusion, the survival of settled F. serratus germlings is mainly determined by canopy sweeping and their growth is retarded in the presence of a canopy and at high settlement density.

• ALGAE
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• 제26권2호
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• pp.193-200
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• 2011

The stress tolerance ability of Pelvetia canaliculata (L.) Dcne. Et Thur. and Fucus spiralis L. to temporary and periodic emersion stress was examined in order to test the following hypotheses: The upper shore alga, P. canaliculata is more tolerant to desiccation than F. spiralis in the germling stage and the former outgrows the latter under desiccation stress; Germling stress tolerance of the two species is age-specific; Crowding of germlings protects them from desiccation, irrespective of the species involved. Germling growth of the two species was retarded with increasing exposure period and was age-specific, as they were air-exposed at an earlier stage. After 16 days, the length of Pelvetia germlings was similar between 2-day-old germlings (125-140 ${\mu}m$) and 7-day-old germlings (134-140 ${\mu}m$), which were air-exposed during the same period (0, 6, 12, 24, 48, and 72 h) at the two different ages. However, Fucus germlings were significantly larger at 7-day-old germlings (211-277 ${\mu}m$) than at 2-day-old germlings (184-278 ${\mu}m$), especially in the treatments of 48 and 72 h. These results indicate that Fuscus grow faster than Pelvetia and that the growth response of germlings to temporary emersion stress is more sensitive in Fucus than that in Pelvetia. Growth of germlings of both species was reduced with increasing density under favorable growth conditions (submerged control and 6 h / 12 h exposure treatments) in the periodic air-exposed experiments using tidal tanks, but was enhanced under severe emersion stress conditions. P. canaliculata showed better growth at 6 h exposure treatment than that of the control, under continuous submergence, indicating that Pelvetia germlings require a periodic exposure period. Fucus germlings always grew faster than those of Pelvetia and did best in mixed cultures, whereas Pelvetia did least well when mixed with Fucus germlings. The adverse effects of F. spiralis on P. canaliculata were greater than those of Pelvetia cohorts. The outcome of interspecific competition between F. spiralis and P. canaliculata gemlings was slightly altered by exposure period but not to such an extent as to change the outcome.

• Animal cells and systems
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• 제7권2호
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• pp.127-132
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• 2003

Effects of genotype, settlement density and irradiane on the growth, mortality and population structure of Fucus serratus germlings were examined in the laboratory. The growth of F. serratus germlings was influenced by genotype of parent plants, which is likely to occur by microclimatic differentiation of substrata. The growth of germlings were greater at lower densities than higher densities indicating that intraspecific competition between germlings occurred within three weeks. Also, the growth of F. serratus germlings was better at $120\mumol\;m^-2/s^-1$ than at $60\mumol\;m^-2/s^-1$. However, mortality of germlings was determined by settlement density rather than irradiance. In population structure, skewness was increased at low irradiance and high density indicating that population structure could be changed by intraspecific competition. Thus, it is concluded that genotypic differentiation of F. serratus germlings occurred in a microgeographic scale, and the experimental density and irradiance level affected the growth of germlings.

• 한국식물병리학회지
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• 제11권4호
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• pp.292-297
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• 1995

We developed an in vitro assay method for evaluating plant growth promotion and providing an evidence that the growth promotion is rendered by growth enhancing factors. The amendment of culture filtrates of Trichoderma harzianum T95 and Gliocladium virens G872 and G872B in Murashige and Skoog (MS) agar medium enhanced the cotyledon growth of cucumber in terms of fresh weight and primary leaf area of cucumber cotyledon cuttings, of which the treatment of G. virens G872B was the most effective. The mycelial culture filtrate of G872B was more effective in the growth promotion than its conidial germling filtrate. The addition of 1% sucrose in MS mineral medium with 0.1% culture filtrates of the antagonists (T95 and G872B) was optimum for enhancing the effect of the filtrates on the growth of cotyledon cuttings in vitro. When cucumber seeds treated with G872B, Pseudomonas putida Pf3 or the G872B-Pf3 mixture were planted in a greenhouse, the rate of seed germination, biomass of shoot and root, and yield of cucumber fruits were increased, especially by G872B or the G872B-Pf3 mixture. Correspondingly, cucumber fruit yields in early to middle-cycles of harvest were significantly greater in the plots of G872B than the control and Pf3-treated plots, and the final yield was highest in the plots of the G872B-Pf3 mixture applications.

• 한국환경생태학회지
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• 제29권1호
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• pp.7-13
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• 2015

To examine the relationship between competition and environmental factors, the germlings of Ascophyllum nodosum (L) Le Jolis and Fucus vesiculosus L. were cultured in monocultures and mixtures of the two species under two different exposure and nutrient levels. Both intra- and inter-specific competition were examined in comparison of the mortality and growth of germlings in monocultures and mixtures of the two species. The mortality of germlings increased with increasing density and emergence periods both in the monoculture and mixtures of the two species, and the mortality of Ascophyllum was significantly higher than that of Fucus both in submerged and emerged treatments. The growth of germlings of both species reduced with increasing density but F. vesiculosus always grew faster than Ascophyllum. The values of log output ratio were more than 0.1, indicating that Fucus 'won' in the competitive battles with Ascophyllum under two nutrient- and air-exposure levels. Log output ratio was greater in high than in low nutrients, indicating that the growth of Fucus is more enhanced than that of Ascophyllum in high nutrients. In the present study, the outcome of inter specific competition between germlings of Fucus vesiculosus and Ascophyllum nodosum was slightly altered by duration of emergence and nutrient concentration, but not to such an extent as to change the outcome.

• 환경생물
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• 제19권1호
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• pp.7-17
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• 2001

해조류의 최적생장 조건과 내성범위는 그 발달단계에 따라 다양하게 나타날 수 있다. 특히 초기 정착단계에서의 생장은 성체로의 성공여부를 결정하는데 있어 중요한 의미를 갖는다고 할 수 있다. 본 연구는 녹조 구멍갈파래 (Ulva pertusa)의 생식세포와 발아체를 이용하여 무기영양염류와 중금속이 발아와 발아체 생장에 미치는 영향을 알아보고 이들의 내성범위 및 최적조건을 구하고자 하였다. 먼저 광량에 따른 발아율은 동해와 서해해수 조건 모두에서 광량이 증가함에 다라 빠르게 증가하였으며 최적광량은 100$\mu$mo1m$^{-2}$ s$^{-1}$이었다. 30$\mu$mo1 m$^{-2}$ s$^{-1}$ 이하의 광량에서 동해수에서의 발아율은 서해수에서보다 높았으며 60$\mu$mo1 m$^{-2}$ s$^{-1}$이상의 경우 두 해수조건에서 유사하게 나타났다. 발아체의 생장 또한 광량이 증가함에 따라 증가하였으며, 서해수보다 동해수에서 빠르게 생장하였다. 또한 광량이 증가함에 따라 발아체의 세포수가 증가하였으며 최적광량은 100$\mu$mo1 m$^{-2}$ s$^{-1}$이었고, 60$\mu$mo1 m$^{-2}$ s$^{-1}$ 이하의 광량에서 서해수보다 동해수에서 발아체의 세포수가 빠르게 증가하였다. 인산염 농도에 상관없이 질산염 농도가 증가함에 따라 발아율이 증가하였으며 배양 3일 후에 질산염 2.5 ppm에서 발아율이 가장 빠르게 증가하였다. 발아체의 생장과 세포수 또한 인산염 농도에 상관없이 질산염 농도가 증가함에따라 증가하였으며, 배양 8일 후에는 질산염 0.5 ppm에서 발아체의 생장이 늦춰지는 것으로 나타났다. 구리의 농도가 증가함에 따라 발아율, 발아체의 생장 및 세포수 모두 급격하게 감소하였으며, 납농도에 상관없이 구리 1 ppm은 구멍갈파래의 생식세포와 발아체 생장 또는 생존에 치명적으로 작용하는 것으로 나타났다.

• Ocean and Polar Research
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• 제40권4호
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• pp.203-212
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• 2018

Zoospore release and germling growth of endophytic Ulvella ramosa were examined under various temperatures (10, 15, 20, $25^{\circ}C$) ${\times}$ irradiances (20, 60, $100{\mu}mol\;photons\;m^{-2}s^{-1}$). Additional growth experiments were performed at different salinities (15, 25, 35, 45 psu) and daylengths (8, 12, 16 h). Growth of host Gracilaria vermiculophylla (Ohmi) Papenfuss was estimated under combinations of temperatures (15, 20, 25, $30^{\circ}C$) and irradiances (20, 60, $100{\mu}mol\;photons\;m^{-2}s^{-1}$). Endophyte effects on the host growth were tested in the two temperatures (20, $30^{\circ}C$) and irradiances (60, $100{\mu}mol\;photons\;m^{-2}s^{-1}$). Zoospore release was maximal at $20^{\circ}C$ and $20{\mu}mol\;photons\;m^{-2}s^{-1}$, and germlings grew best under $20^{\circ}C$ and $60{\mu}mol\;photons\;m^{-2}s^{-1}$. No salinity effect on the growth of endophytes was found but endophyte growth was maximal under the daylength of 12 h. G. vermiculophylla grew better at higher irradiances but no growth differences were found between temperatures of $15-30^{\circ}C$. The growth of host species was significantly inhibited by endophytes under $20^{\circ}C$ and $60{\mu}mol\;photons\;m^{-2}s^{-1}$, but host G. vermiculophylla grew well in the endophyte inactive culture conditions of $30^{\circ}C$ and $100{\mu}mol\;photons\;m^{-2}s^{-1}$. In conclusion, endophyte effects on the production of host G. vermiculophylla could be minimized by controlling cultivation depth and harvest period to inhibit endophyte activity.