• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.112-116
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• 1999

In theprevious Hizikia cultivation, holdfasts were threw into the sea after harvesting in May; the young thalli(5$\~$10cm in length) of Hizikia are annually collected from natural bed by seed collectors for the cultivation, resulting in a ruined natural populations. Therfore, the reuse method of holdfasts by regeneration capability of Hizikia fusiformis, was investigated. The effects of emergence on the growth of regenerated thalli from holdfasts over 6 months of outdoor culture from May to November, 1995. The vegetative growth from the holdfasts was good under the emergence of 3hrs/day on the air than 0, 1 and 2hr/day. The regeneration of holdfasts was determined by measuring total length, number of stipe and weight. The growth was facilitated under the exposure condition of 1$\~$3 hrs/day on the air. Outdoor cultivation for the comparsion of to artifical natural seeds were conducted from December 1995 to May 1996. There was no significant differences(0.05< P) between the two kinds of seeds. Therefore, artificial seed maybe used as a replacement for the natural seed in Hizikia cultivation. From the results, an useful method was established to obtain young fronds for the cultivation using the reuse method of holdfast, to conserve the natural population of Hizikia.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.1
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• pp.117-120
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• 1999

High yields of protoplasts were obtained following enzymatic digestion of the vagetative thalli of marine green alga Monostroma nitidum. The enzyme mixtures containing $4\%$ Cellulase R-10+$3\%$ Macerozyme R-10+$3\%$ Abalone acetone power produced $4.41\times10^6$ protoplasts per 300 mg of fresh tissue. The highest yield of protoplasts was obtained by 270 minutes treatment of the thalli in enzyme solution. Freshly isolated protoplasts were spherical in shape and ranged between $13\~33\mu$m in diameter. The high efficiency of differentiation were obtained by incubating freshly isolated protoplasts in 0.4 M mannitol f/2 medium for 7 days and then transferring to 0.2 M mannitol f/2 medium. Protoplasts began to form new cell walls three days after initial culture and began to germinate after 10 days, and then form a leafy thallus after further culture in f/2 medium. The addition of antibiotics in media inhibited the differentiation of protoplasts in culture.

• 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.

• ALGAE
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• v.39 no.1
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• pp.17-30
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• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.257-260
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• 2001

The effects of light, desiccation and salinity on the discharge of spores in Korean agarophyte, Gracilaria verrucosa were studied. Among the examined factors, light after darkness was the most effective for spore discharge. The maximum release of tetraspores was induced at 24 h after the treatment. Desiccation also seems to be conductive to the release of tetraspores. However, its effect, as in treatment of distilled water for salinity, was hardly found in induction of carpospore discharge. This may suggest that spore discharge in this alga is primarily related with photoperiodic rhythm. Also it appears that the amount of light energy received by fertile thalli also significantly affects to the spore release, considering relationship between the amount of the discharged spores and the elapsed time after treatment.

• ALGAE
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• v.26 no.3
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• pp.221-227
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• 2011

There are three carpet-like Codium species with a broadly expanded thallus reported from Korea and Japan: C. latum Suringar, C. tapetum Y. Lee, and C. tenuifolium Shimada, Tadano and J. Tanaka. During surveys of green algal diversity, we encountered a Codium species with carpet-like thalli from several sites on Jeju Island. To confirm the taxonomic identity of these specimens, we studied the morphological features and obtained rbcL gene sequences. The morphological and sequence data indicated that the carpet-like Codium specimens from Jeju are C. tenuifolium from Japan, but distant from Japanese C. latum. We propose that the carpet-like specimens from Jeju should be renamed C. tenuifolium, instead of C. tapetum or C. latum. C. tenuifolium is characterized by a tenuous, carpet-like and erect thallus with a very short and slightly compressed stipe arising from a discal holdfast, sub-pyriform and clavate utricles with a tumid and swollen apical head, and globular or sub-globular gametangia issued at the basal portion of the utricles.

• ALGAE
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• v.29 no.4
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• pp.289-297
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• 2014

The taxonomic status and the distribution of Rosenvingea species need attention because of the difficulties in morphological identification in the laboratory as well as in the field. We analyzed mitochondrial cox3 and plastid psaA gene sequences from Rosenvingea species from Vietnam, Mexico and Panama in combination with morphological examinations. Our results confirmed the occurrence of R. intricata and R. orientalis in Vietnam. R. intricata formed dense decumbent mats with many flat branches, often inter-adhesive, and was up to 5 cm in diameter. R. orientalis thalli were up to 18 cm long with narrow (less than 2 mm in width) tubular to compressed fronds. Both cox3 and psaA phylogenies revealed the non-monophyly of the genus Rosenvingea, as reported previously for other scytosiphonacean genera.

• ALGAE
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• v.20 no.2
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• pp.99-112
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• 2005

This monographic study presents morphological descriptions of eight species of Padina collected from the Visayas and Mindanao regions of southern Philippines, including distributions of each species and a taxonomic key for all the species examined. Of these species, three are new records for the Philippines, namely: P. fernandeziana Skottsberg and Levring, P. jonesii Tsuda and P. moffittiana Abbott and Huisman. One species, P. antillarum (Kützing) Piccone, represents a new nomenclatural record, which is applied to a Philippine species for the first time. Four species previously reported in the Philippines are reconfirmed and described P. australis Hauck, P. minor Yamada, P. boryana Thivy and P. sanctae-crucis Borgesen. All eight species studied have distromatic thalli, except for P. antillarum which is tetrastromatic. Three of these have indusiate sporangia, namely: P. sanctae-crucis, P. moffittianaand P. fernandeziana.

• Mycobiology
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• v.43 no.2
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• pp.157-162
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• 2015

Lichen-forming fungal proteins have been seldom searched due to many difficulties in their extraction. Phenols, quinones, proteases, and other components released during cell disruption have been known to be the greatest challenges related to protein extraction from lichens. To overcome these problems and maintain good electrophoretic resolution and high protein concentration, an extraction buffer containing polyvinylpolypyrrolidone, ascorbic acid, Triton X-100, polyethylene glycol, proteinase, and oxidase inhibitors in sodium phosphate buffer was developed. This extraction buffer showed high efficiency for all lichen species tested in the study.

• ALGAE
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• v.19 no.4
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• pp.283-292
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• 2004

Psilothallia is a ceramiaceous red algal. genus that includes three species worldwide: P. dentate, P. siliculosa, and P. striate. The latter two species are limited to Australian waters, and P. dentate occurs in Japan. We here report the detailed morphology of P. dentate, and also determined plastid protein-coding psbA in P. dentate and putative relatives. Psilothallia dentate is distinguished by compressed thalli with alternate-distichous determinate branchlets, six periaxial cells, rhizoidal filaments in axes, cystocarps with 7-8 involucral filaments, spermatangia on branched filaments, and tetrahedrally divided tetrasporangia on branched filaments. Psilothallia dentate is also unusual in that cystocarps, spermatangial clusters, and tetrasporangial tufts are formed on short adventitious indeterminate branches arising on axils of determinate branchlets. The phylogenetic trees of psbA sequences show that P. dentata was nested in a monophyletic Glade comprising Ptilota, Neoptilota, and Plumaria. This result suggests that the taxonomic position of P. dentate may be transferred from the tribe Rhodocallideae to the Ptiloteae.