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

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.443-448
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• 2001

This study was carried out to obtain the basic informations on the characteristics of gametophytes formation and microspore germination in Astragalus membranaceus Bunge. Pollen mother cells passed through meiosis when the flower bud length reaches around 3.5 mm, thus creating the tetrad when it is 4.0 mm long. Pollen attains full growth when the bud is about 10.0 mm long and the anther is found to dehisce when the length of tate bud reach around 12.0 mm. Embryo sac develops at a similar speed as pollen did and it attains its full growth when the bud is about 10-12 mm long. After being stored at 4$^{\circ}C$ or -4$^{\circ}C$, the pollen maintained its germination ability to almost full extent by the 30th day after store. However, the germination rate at room temperature (23~28$^{\circ}C$) decreased below 3％ by the 3rd day of storage and so did the germination speed.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.347-352
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• 2013

Outdoor cultivation experiment was conducted with artificial seeds using free-living gametophytes and zoospores of Ecklonia cava to develop FLG (free-living gametophyte) seeding technique. Growth of thalli between FLG and zoospore seeding groups was compared monthly from May to October 2009 at culture farm in Wando, Korea. In September 2009, thalli in the FLG seeding experimental group were $35.9{\pm}0.8$ cm in length, $24.1{\pm}2.62$ g in weight, $2.32{\pm}0.26$ kg $m^{-1}$ in biomass and $22.0{\pm}2.8$ individuals $m^{-1}$ in density. There were no significant differences in length, weight, biomass and density between FLG and zoospore seeding group. Therefore, the FLG seeding technique could replace the zoospore seeding method which would eventually contribute in restoration and conservation of natural resources.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.114-120
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• 2009

The most effective conditions of in vitro culture were studied for mass propagation of Pteris cretica 'Wilsonii'. Spores of the species germinated within 7 weeks. The greatest proliferation was obtained with Knop and Hyponex media, but growth was more effective in Hyponex medium. MS medium induced necrosis of prothalli in all strength of nitrogen and sucrose except in case of 0% sucrose. Hyponex medium supplemented with 1% sucrose and 0.6% agar promoted propagation and growth of prothalli. In Hyponex medium, optimal inoculation method was homogenization, but in MS medium dividing colonies of prothalli was more effective. Culturing on solid medium was more effective than liquid culture method. Liquid culture induced necrosis of prothalli. Shaking cultured prothalli showed good growth, but propagation was inhibited compared to those cultured on solid medium.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.24-28
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• 1981

As one of the fundamental studies for the breeding of marine algae, this paper deals wit_the effects of plant hormone on the growth of microscopic filamentous gametophyte of Undaria pinnatifida. The results obtained are summarized as follows: (1) All zoospores were settled on slide glass, germinated and developed into gametophytes, without the growth of germination tubes when treated with 0.1 mg/l of 2.4-D, or 0.1, 1.0, or 5.0 mg/1 of Keinetin. (2) The best growth effect in total average was observed at 0.1 mg/1 of Keinetin, when the growth-rate was $248.9\%$ in contrast with control, and was followed by 1.0 mg/1 of IAA ($243.3\%$), and 0.05 mg/1 of 2.4-D ($205.6\%$). (3) It was certain that the growth-effect by each plant hormone had some differences between male and female gametophytes. IAA was very effective in the growth of male gameto-phytes but Keinetin in that of females. Especially in females, the efficiency of Keinetin was recorded best at $239.0\%$ at 5.0 mg/l and $222.0\%$ at 0.1 mg/1. On the other hand, it was $195.1\%$ in its best at 0.5 mg/1 of IAA, and $146.6\%$ was recorded best in 2.4-D at 0.05 mg/1.

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

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.337-342
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• 2009

Present studies were conducted to evaluate the effects of medium strength(MS and Hyponex), carbon sources and their concentrations, agar concentrations, and inoculation amounts on prothallus propagation of Pterdium aquilinum var. latiusculum(Desv.) Underw. ex Hell in vitro. The optimum MS medium strength for prothallus propagation was 2MS concentration. Phosphate source was most effective for prothallus growth of P. aquilinum var. latisculum. The addition of 1% sucrose or glucose to MS medium promoted prothallus multiplication. Growth of prothallus was not affected by agar concentration. Propagation of homogenized prothallus was vigorous even in liquid medium. Chopped gametophytes(100 and 200 mg) were inoculated on 250 ml ${\Delta}$flask with 100 mL of 2MS concentration medium and suspension culture was done at 100 rpm for 22 days. After 20 days, prothallus multiplication slowed down, so 100 mg of chopped prothalli is recommended for initial inoculation, since initial amount of inoculum did not affect subsequent prothallus multiplication. Consequently after 20 days of suspension culture, prothallus should be subcultured or transplanted outside of growing vessels.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.467-480
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• 2002

The development of the female gametophyte of Corydalis albipetala, C. ambigua, C. filistipes, C. nobilis, C. solida, C. ophiocarpa have been comparatively investigated using laser scanning confocal microscope (LSCM) and light microscope. An archesporium was originated from one of the outmost parietal cells beneath the one-layered epidermis of protuberant nucellus, and acted directly as a megaspore mother cell (MMC). These species had linear tetrads after successional meiotic division during the megasprogenesis. A functional megasprore developed from one of the tetrad in the chalazal end, and the rest three being degenerated. The developmental type of the female gametophyte was monosporic in accordance with the Polygonum type. Prior to anthesis the female gametophyte was organized. So mature embryo sac was comprised a three-celled egg apparatus, three large antipodals were developed from the apex of each antipodal cell, and extended toward micropylar end to be contacted with egg apparatus. Two synergids were usually observed as degenerated condition, and in this time the apices of antipodal haustoria were connected with the degenerated synergids. The developmental characteristics of seven-nucleate female gametophytes were common in all the species investigated. But the shape of mature embryo sac was ovoidal in C. albipetala, C. filistipes, C. ophiocarpa and C. solida, reflexed in C. ambigua, and rather flattened ovoidal in C. nobilis. Also, the type of megasporangium was anatropous in all the species except C. ambigua with campylotropous ovule.

• Journal of Aquaculture
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• v.20 no.1
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• pp.7-13
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• 2007

The seed production of Ecklonia stolonifera Okamura was studied under laboratory conditions through the embryonic sporophyte stage and the field cultivation was conducted in eastern coast of Korea. The germination of zoospores occurred within 3 days and the growth of gametophytes was most rapid at $25^{\circ}C$ and $20\;{\mu}mol{\cdot}m^{-2}s^{-1}$. Sporophyte growth was highest at $20^{\circ}C$ and $20\;{\mu}mol{\cdot}m^{-2}s^{-1}$ and lowest at $25^{\circ}C$ and $80\;{\mu}mol{\cdot}m^{-2}s^{-1}$. In the nursery culture of E. stolonifera lasting for 2 weeks in January, the initial blade length of E. stolonifera (about $500\;{\mu}m$) grew to $526.3{\pm}176.0\;{\mu}m$ at water temperature of $12.05^{\circ}C$. The blade length and width reached their maxima in July, after which the ends of blade and stem began to degrade with the increase in water temperature. The degraded end of the blade started to regenerate in October, when water temperature began to decline. This species can be considered a potential candidate for aquaculture, increasing in the availability of raw material and aiding in recovery of seaweed bed.

• Journal of Aquaculture
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• v.19 no.3
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• pp.216-221
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• 2006

The Effect of different temperatures and photon irradiance on the growth of crust and the regeneration of tissue fragments of the commercially important red alga Grateloupia acuminat Okamura were examined in laboratory cultures. The tetraspore developed into basal crusts and produced upright thalli. Crust grew very fast at $25^{\circ}C$ and $80{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ after one week in indoor culture. However, they stopped growing after three weeks. Maximum growth was $275{\mu}m$ in diameter. They required four weeks to get upright thalli at $5^{\circ}C$, while only three weeks were required at $10^{\circ}C$. When different light intensities were compared at $15^{\circ}C$, cells of the crusts were well differentiated $80{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and consistently divided so that upright thalli were produced. In aeration culture, the upright thalli grew up to 6.5 cm in length within 4 months. Thus, it is possible to produce mass cultures of Grateloupia in the field. In addition, female and male gametophytes developed from the tetraspores and they were fertilized to produce tetrasporohyte thalli. By this procedure, the normal life cycle of the red alga G. acuminata was completed.