• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.252-258
• /
• 2006

The most effective conditions of In vitro culture and ex vitro sporophyte formation from prothallus were studied for mass propagation of Dyropteris varia. The most effective medium of prothallus proliferation was Murashige and Skoog's basal medium supplemented with 10:50mM of $NH_4^+:NO_3^-$ and 2% sucrose. The optimum pH level was 5.8 and prothallus growth was promoted on medium containing $0.6{\sim}0.8%$ agar. Almost of the tested growth regulators (NAA, IAA, 2,4-D, BAP, kinetin and 2ip) were inhibitory in prothallus proliferation as the concentration of growth regulators became higher. The highest number of sporophytes was obtained by transplanting prothallus on compost only than on any other soil compositions. Sporophyte formation was promoted remarkably by soaking prothallus with $100{\mu}M\;GA_3$ for 3 hours.

• Journal of Plant Biology
• /
• v.34 no.1
• /
• pp.59-66
• /
• 1991

The morphotaxonomic characters and life history of Symphyocladia latiuscula (Harvey) Yamada were investigated with field and laboratory culture materials. The species is well defined by a 5-15 cm hight, entirely corticated thallus and congenital fusion of 5-7 segments between main axis and laterals. Although all the reproductive structures are basically similar to those of other species of the genus, it is characteristic that the pinnulae are transformed into the flabellated tetrasporangial stichidia. Vegetative trichoblasts are known to be absent in the Pterosiphonieae, but their presence in S latiuscula does not accept its taxonomic position in that tribe. As a result, the occurrence of vegetative trichoblast is not useful for a taxonomic character to distinguish the tribes. The species shows a Polysiphonia-type life history involving a dimorphic alternation of gametophytes and sporophytes in culture and field. It grows below the middle intertidal zone in all the coasts of Korea throughout the year, although fertile plants are normally found during the summer months.months.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.1
• /
• pp.71-77
• /
• 2011

The effects of temperature, light, and salinity on the growth of Costaria costata and Undaria pinnatifida juveniles were examined in laboratory cultures. In a cultivation farm, the monthly yield and density were also investigated between December and April for C. costata and between December and March in 2007 and 2008 for U. pinnatifida. The relative growth rates (RGRs) were greater at $20{\sim}60\;{\mu}mol$ photons $m^{-2}s^{-1}$ than at low ($0{\sim}10\;{\mu}mol$ photons $m^{-2}s^{-1}$) and high ($100{\sim}180\;{\mu}mol$ photons $m^{-2}s^{-1}$) irradiance levels. The optimal growth conditions for the two species were $17^{\circ}C$, 35 psu, $60\;{\mu}mol$ photons $m^{-2}s^{-1}$, and a daylength of 12 h, indicating that C. costata and U. pinnatifida have very similar growth responses to temperature, light, and salinity. However, the growth responses of the two species to various environmental factors were different; C. costata grew faster than U. pinnatifida but the latter species grew well at low salinity. The monthly yield of C. costata and U. pinnatifida increased steadily over the study period, and it was maximal in March for both species, but the yield of U. pinnatifida was greater than that of C. costata.

• Horticultural Science & Technology
• /
• v.35 no.1
• /
• pp.46-58
• /
• 2017

This study was conducted to investigate the optimal conditions for spore germination, prothallus propagation, sporophyte formation and seedling growth in Microlepia strigosa (Thunb.) C. Presl. Spore germination and prothallus development were promoted by low concentrations of Knop medium nutrient solution. The optimal medium for prothallus propagation and antheridium formation was 2X MS medium with 3% sucrose. The activated charcoal content of the medium did not affect prothallus proliferation. Among the various combinations of culture soil (bedding soil, peat moss, perlite and decomposed granite), a mixture of bedding soil, peat moss and decomposed granite at a ratio of 1 : 1 : 1 (v : v : v) had a positive effect on sporophyte formation. The most efficient conditions for promoting the growth of whole plants (sporophyte seedlings) were 50 - cell plug trays filled with a mixture of bedding soil and decomposed granite at a 2 : 1 (v : v) ratio.

• Korean Journal of Plant Resources
• /
• v.22 no.5
• /
• pp.394-402
• /
• 2009

Adventitious shoots were induced from pinnae, petiole and rhizome in Pteris cretica 'Wilsonii' in order to develop the efficient mass propagation method, using in vitro culture. Only homogenized rhizome segments could regenerate young sporophytes. Efficient regeneration of multiple shoots was obtained on the one-eighth strength MS medium containing 1% sucrose, and $50mg{\cdot}L^{-1}$ $NaH_2PO_4$. To achieve higher rate of regeneration from rhizome segments, rhizome segments were exposed to growth regulators for 2 months and then subcultured on hormone-free medium. The greatest shoot regeneration was obtained by $1{\mu}M$ kinetin with $5{\mu}M$ NAA. BA was effective in formation of GGB (kind of meristems), but they showed low shoot regeneration rate. Plants obtained from present experiments were transplanted to examine good environmental conditions for acclimation. Juvenile plants obtained by the one-eighth strength MS medium showed highest survival rate and vigorous growth at the seedling stage.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.5
• /
• pp.315-322
• /
• 2007

Kjellmaniella crassifalia Miyabe is one of the valuable seaweed crops cultured in the Korean coastal waters of the East Sea. Unfortunately recent environmental changes have adversely influenced its growth, prompting the need to develop techniques for species restoration. To obtatin biological information, the growth of the species was monitored for one year. The maximum blade length, $110{\pm}45cm$, was attained in July, and zoospores were released in November. The optimum culture conditions allowing juvenile sporophytes to grow to young blades consisted of $20{\mu}mol/m^2s\;at\;10^{\circ}C$ under which the blade length grew to $1,732.5{\pm}143.3{\mu}m$ in 42 days. Sporangial sori started to form in September, reaching 85% maturity in November and 89% maturity in December. Examining the growth of the species according to depth, the individuals growing at 5 meters grew the most, reaching a blade length of $75.9{\pm}18.9cm$ in August.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.4 no.3
• /
• pp.226-236
• /
• 1999

Growth, reproduction, mortality, and production of Laminaria japonica were experimentally studied at a cultivation ground on the coast of llkwang, where the largest amount of cultivated Laminaria has been produced in Korea. For this experiment, young sporophytes (0.33 cm in mean length) grown in the laboratory were transplanted at the depth of 3 m and field surveys on them were conducted twice a month from December, 1995 to August, 1996. Plants exhibited an annual life span; they were completely dead by August. Frond width, thickness, and wet weight showed similar pattern of seasonal growth and reached their maxima in July, but frond length showed no more increment after May. Maximum mean frond length and weight were 199.8 cm and 333.0 g wet wt., respectively. Overall meristematic growth in length and weight were 384.0 cm and 393.6 g wet wt., respectively. Absolute growth rates (AGR) which were calculated from the length of tissue developed from meristem varied seasonally; AGR of length and weight reached maxima in March (3.6 $cm{\cdot}d^{-1}$) and May (3.8 g wet $wt{\cdot}d^{-1}$), respectively. Absolute attrition rates gradually increased from February to July. Seasonal differences in growth and attrition rates appeared to be related to seawater temperature and nitrogen concentration in seawater. Reproductive sporophytes bearing sprorangium sorus began to occur from April, and the ratio of sorus area to blade area reached its maximum in July (0.034). Survival rate was exponentially decreased; more than 90% of plants decayed within 56 days after outplanting. After February, mortality was size-specific; mortality of smaller plants less than 30 cm in length were relatively higher. Maximum biomass occured in July (285.6 kg wet $wt{\cdot}m^{-2}$) and annual production was 758.7 kg wet $wt{\cdot}m^{-2}$.

• Journal of Aquaculture
• /
• v.18 no.4
• /
• pp.299-304
• /
• 2005

Laboratory culture of the native kelp Kjelimaniella crassifolia and the introduced species Laminaria japonica in east coast of Korea were compared at each stage of their life cycles. In the zoospore stage, L. japonica grows optimally at a water temperature of $15{\~}20^{\circ}C$ achieving $95\%$ spore release in 24 hours, whereas K. crassifolia requires 48 hours to achieve $90\%$ spore release in these conditions. Good growth of gametophytes occurred at $10^{\circ}C$ and $15^{\circ}C$ in both species. L. japonica grows optimally under high light intensity ($80{\~}120{\mu}mol{\cdot}m^{-2}s^{-1}$) while K. crassifolia grows best under low light intensity ($40{\~}60{\mu}mol{\cdot}m^{-2}s^{-1}$). Growth of juvenile sporophytes of L. japonica was good in various water temperatures ($10{\~}20^{\circ}C$) and light levels ($40{\~}120{\mu}mol{\cdot}m^{-2}s^{-1}$) while K. crassifolia grew to optimal blade length only under specific conditions ($10{\~}40{\mu}mol{\cdot}m^{-2}s^{-1}$). While the optimal culture conditions for K. crassifolia were more constrained than those of L. japonica which tolerated a wide range of water temperatures and light intensities, the laboratory culture conditions for both of these species reflect the natural environment in which these species are found.

• Horticultural Science & Technology
• /
• v.35 no.4
• /
• pp.480-489
• /
• 2017

We investigated a suitable method for in vitro germination of spores, propagation of prothalli, and the formation of sporophytes in the fern Dryopteris nipponensis Koidz. Spore germination rate was relatively high regardless of culture medium. Prothallus development was faster in Knop medium than in Murashige and Skoog (MS) media. Prothalli used in all experiments were obtained from germinated spores, and were cultivated in different concentrations of media components. The active formation of sexual organs such as antheridium made 1MS medium suitable for prothallus propagation, although there was a lower propagation ratio compared to Knop medium. Growth and morphogenesis of prothalli were most effective on 1MS medium containing 2% sucrose, and 60 mM of total nitrogen source with 20:40 mM ratio of $NH_4{^+}:NO_3{^-}$. To select a suitable soil composition for sporophyte formation, ground prothalli were cultivated on single and mixed soils using bed soil, peat moss, perlite, and decomposed granite for 14 weeks. Bed soil promoted sporophyte formation and growth regardless of single or mixed use. In particular, a mixture of bed soil and decomposed granite in a 2:1 ratio (v:v) led to accelerated sporophyte formation ($0.83/cm^2$).

• Korean Journal of Environmental Biology
• /
• v.17 no.1
• /
• pp.1-9
• /
• 1999

Numerous observations revealed strong evidence of increased middle ultraviolet radiation or UV-B (280 ~ 320 nm) at the earth's surface resulting from stratospheric ozone depletion. UV is the waveband of electromagnetic radiation which is strongly absorbed by nucleic acids and proteins, thus causing damage to living systems. It has been recorded in the East Sea, Korea that solar UV-B impinging on the ocean surface penetrates seawater to significant depths. Recent researches showed that exposure to UV-B for as short as 2h at the ambient level (2.0 Wm$^{-2}$) decreased macroalgal growth and photosynthesis and destroyed photosynthetic pigments. These may suggest that UV-B could be an important environmental factor to determine algal survival and distribution. Some adaptive mechanisms to protect macroalgae from UV-damage have been found, which include photoreactivation and formation of UV-absorbing pigments. Post-illumination of visible light mitigated UV-induced damage in laminarian young sporophytes with blue the most effective waveband. The existence of UV-B absorbing pigments has been recognized in the green alga, Ulva pertusa and the red alga, Pachymeniopsis sp., which is likely to exert protective function for photosynthetic pigments inside the thalli from UV-damage. Further studies are however needed to confirm that these mechanisms are of general occurrence in seaweeds. Macroalgae together with phytoplankton are the primary producers to incorporate about 100 Gt of carbons per year, and provide half of the total biomass on the earth. UV-driven reduction in macroalgal biomass, if any, would therefore cause deleterious effects on marine ecosystem. The ultimate impacts of increasing UV-B flux due to ozone destruction are still unknown, but the impression from UV studies made so far seems to highlight the importance of setting up long-term monitoring system for us to be able to predict and detect the onset of large -scale deterioration in aquatic ecosystem.