• Korean Journal of Environmental Biology
• /
• v.33 no.2
• /
• pp.248-255
• /
• 2015

Induction of regeneration and maturation of the free-living gametophytes of Saccharina japonica was studied at four temperatures (5, 10, 15 and $20^{\circ}C$), four levels of irradiance (5, 10, 20 and $40{\mu}mol\;m^{-2}\;s^{-1}$) and three photoperiods (14 : 10, 12 : 12 and 10 : 14 h L : D). Female gametophyte fragments were maintained in active regeneration without reaching sexual maturity under conditions of $15^{\circ}C$, $20{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D), whereas the conditions for male gametophytes were slightly different at $15^{\circ}C$, $5{\mu}mol\;m^{-2}\;s^{-1}$, 14 : 10 h (L : D). The sexual maturation of female and male gametophytes took place under $5^{\circ}C$, $20{\sim}40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D) and $15^{\circ}C$, $40{\mu}mol\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D), respectively. These results provide basic information for controlling the regenerationand maturation of free-living gametophytes for strain improvement and cross breeding of S. japonica.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.3
• /
• pp.505-510
• /
• 1997

Temperature and light responses on the growth and maturation of gametophytes of Undaria pinnatifida were studied in laboratory culture. The effect of the environmental factors on formation of young sporophyte of U. pinnatifida was also examined in the same culture system. Maximum growth and rapid maturation of the gametophytes were observed at $12:12LD,\;17^{\circ}C$ and 60{\mu}mol\;m^{-2}s^{-1}. However, they survived in a wide range of the examined temperature, light intensity and photoperiod. Particularly they survived under continuous dark condition (0:24LD) until 210 days without any growth and maturation, but died within $10\~40$ days at $30^{\circ}C$. This suggests that optimum rendition for conservation of Undaria gametophytes is under continuous dark photoperiod at $17\~25^{\circ}C$.

• Korean Journal of Environmental Biology
• /
• v.35 no.4
• /
• pp.622-630
• /
• 2017

The induction of regeneration and the maturation of the free-living gametophytes of Undaria pinnatifida were studied at temperatures(5, 10, 15 and $20^{\circ}C$), irradiance (5, 10, 20 and $40{\mu}mol\;photons\;m^{-2}\;s^{-1}$) and photoperiods (14 : 10, 12 : 12 and 10 : 14 h L: D). Female gametophyte fragments were maintained in active regeneration without them reaching sexual maturity under conditions of $15^{\circ}C$, $20{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D); by contrast, the conditions for male gametophytes were slightly different at $15^{\circ}C$, $5{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 14 : 10 h (L: D). The sexual maturation of female and male gametophytes took place under $5^{\circ}C$, $20-40{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D) and $15^{\circ}C$, $40{\mu}mol\;photons\;m^{-2}\;s^{-1}$, 10 : 14 h (L : D), respectively. These results provide basic information for controlling the regeneration and maturation of free-living gametophytes for srain improvement as well as the cross breeding of U. pinnatifida.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.1
• /
• pp.15-22
• /
• 2010

These investigations were conducted to standardize several chemical and physical environments affecting in vitro propagation of gametophytes of Climacium japonicum. Propagation of this moss species was established on basal medium containing Knop macro salts and Nitsch and Nitsch trace elements. Primary cultures were initiated from apical shoots of gametophytes. Gametophyte production was accessed using chopped gametophytes, apical shoots and basal shoots. Seven ty pes of culture media and four concentrations of total nitrogen and five strengths of sucrose were tested for in vitro gametophyte production. Light and temperature factors were also evaluated. Apical shoots were the greatest among three types explants used for gametophyte propagation. Medium containing Knop macro salts and Nitsch and Nitsch trace elements was more effective than other types of media. Higher sucrose concentrations showed a positive effect on the elongation and multiplication of gametophytes. Both nitrogen deficiency and excessiveness inhibited gametophyte growth. Light intensity variation showed highly significant changes in numbers, length and fresh weight of gametophytes. Optimum light intensity for gametophyte growth seemed to be around 3000-4000 lx. Both lower and higher temperature had a negative effect on gametophyte propagation and production. This study will provide large scale and high quality propagules, and effective moss propagation system.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.49 no.2
• /
• pp.190-197
• /
• 2016

We examined for differences in the growth and fertility of microscopic stages between Costaria costata and Undaria pinnatifida in crossed temperature×irradiance (12, 17, 22℃×20, 60 μmol photons m^–2s^–1) and daylength×irradiance (8, 12, 16, 24 h×20, 60 μmol photons m^–2s^–1) experimental designs. After 13 days in culture, maximum gametophyte growths of the two species were obtained under the following combinations of factors: 17℃×60 μmol photons m^–2s^–1 and 24 h daylength×60 μmol photons m^–2s^–1. C. costata gametophytes produced sporophytes about 6 days earlier than those of U. pinnatifida. Sporophyte densities were highest in the 12 h daylength×60 μmol photons m^–2s^–1 combination after 20 days in C. costata (9.7 plants mm^–2) and 26 days in U. pinnatifida (9.1 plants mm^–2). However, optimal growth conditions for the microscopic sporophytes differed between species: 17℃×60 μmol photons m^–2 s^–1 for C. costata, 12℃×60 μmol photons m^–2 s^–1 for U. pinnatifida. Thus, C. costata gametophytes grew faster and produced sporophytes earlier than those of U. pinnatifida, even though the haploid gametophytes of the two species responded similarly to environmental conditions. Optimal growth temperatures for the microscopic sporophytes also differed between species.

• ALGAE
• /
• v.26 no.1
• /
• pp.61-71
• /
• 2011

Thirty populations of Chondrus crispus Stackhouse from Nova Scotia were collected during the years 1993 to 2011. Taken from estuaries, wave exposed open coasts, high intertidal rock pools and shallow subtidal habitats, the populations were evaluated for relative abundance of tetrasporophytic and gametophytic life history phases. Over 2,800 thalli were characterized using the resorcinol-acetal test to distinguish the kappa- and lambda-carrageenan containing fronds of gametophytes and tetrasporophytes, respectively. These populations had $77{\pm}5%$ gametophytes (mean ${\pm}95%$ confidence interval), with most populations having gametophyte : sporophyte ratios ranging from 2 : 1 to 9 : 1. No population had a dominance of tetrasporophytes, although two populations had 1 : 1 ratios. A meta-analysis of our data along with previously published accounts showed no significant changes in gametophyte dominance with respect to hypothesized gradients of wave exposure, salinity, or water depth. Significant changes occurred in ratios at five sites where replicate sampling occurred in different years. We conclude that C. crispus in Maritime Canada has a natural ratio of 3 : 1 or greater in stable conditions, and that lower ratios represent recovery from disturbance in which bare substratum is created that is subsequently colonized by carpospores from remaining gametophytic thalli.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.3
• /
• pp.179-185
• /
• 2010

This study was carried out to investigate the optimal culture conditions for gametophytes growth and sporophytes regeneration of Pyrrosia linearifolia in order to provide for the masspropagation system foundation of Pyrrosia linearifolia using their life cycle. Among many different media, 2MS medium was most effective in prothallus proliferation. Prothallus growth was promoted as the total concentration of nitrogen sources increased, and the best result was observed on 120 mM nitrogen. The best concentration of sucrose was 3%. The addition of 5~20 mM IAA, NAA, BA and kinetin promoted the propagation of prothallus. But 2iP demonstrated the most inhibitory effect on prothallus proliferation. Gametophytes shaking-cultured with liquid medium showed similar growth with solid medium and normal formation of reproductive organs. Shoot regeneration was most effective on 1/8MS medium, but growth was promoted on 1/2MS medium. For promotion of shoot regeneration and growth, the suitable concentrations of sucrose and $NaH_2PO_4$ were 1% and $50{\sim}100mg{\cdot}mL^{-1}$ in 1/8MS medium, respectively.

• Korean Journal of Plant Resources
• /
• v.32 no.6
• /
• pp.735-742
• /
• 2019

This study investigated a suitable method that could be applied for Asian chain fern [Woodwardia japonica (L. f.) Sm.] to propagate gametophytes and promote sporophyte formation. The gametophytes used in all experiments were obtained from germinated spores in vitro and were subcultured at 8-week intervals. The most appropriate media for gametophyte propagation was identified by culturing 300 mg of gametophyte in Murashige and Skoog (MS) basal medium (1/8, 1/4, 1/2, 1, 2), and Knop medium for 8 weeks. As a result, fresh weight of the gametophyte was increased by 56.7-fold on MS medium. Moreover, antheridium formation as well as gametophyte growth was improved on MS medium, especially. To improve the sporophyte formation ex vitro, 1.0 g of gametophyte was ground with distilled water and spread on eight combinations onto four different culture mediums, such as bed soil, peat moss, perlite and decomposed granite. Then generation and growth of sporophytes were investigated after cultivation for 10 weeks. As a result of this experiment, peat moss had a promotive effect of sporophyte formation at single-use and mixed culture soils. In particular, a mixture of bed soil, peat moss and perlite in a 1:1:1 ratio (v/v/v) led to the accelerated formation (782.5 ea/pot) and the frond growth of sporophytes. This included increases in length and width of fronds. However, promotive effect of gametophyte growth and sporophyte formation was not found at single-use and treatment with high ratio of bed soil.

• Korean Journal of Plant Resources
• /
• v.19 no.2
• /
• pp.360-364
• /
• 2006

The gametophytes of Cyrtomium falcatum and Cyrtomium caryoptideum var. coreanum arising from spores were mechanically homogenized and cultured In vitro, to study their gametophyte ontogeny and sporophyte development. Homogenized gametophytic tissues formed as one-dimensional filaments after 2 weeks in culture and then glowed into blanched gamatophytes after 4 weeks. After 6 weeks, which were developed to two dimensional plates with apical notch and meristem in central zone. After 8 weeks in culture, apomictic buds were formed on the midribs without archegonium formation and these buds developed to sporophytes after 10 weeks in culture. Flow cytometric analysis of gametophytes and apomictic sporophytes revealed that both forms had the same ploidy level in C. falcatum and C. caryoptideum vu. coreanum, respectively. This is to certify that C. caryoptideum var. coreanum was an apomictic fern as well as C. falcatum.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.3
• /
• pp.290-297
• /
• 2011

The phenology of Campylaephora hypnaeoides J. Agardh and optimal conditions for carpospore release, growth and reproduction were examined in the field and in the laboratory from January to December 2007. In the field population of C. hypnaeoides, approximately 50% of the plants were vegetative during the study period. Additionally, the percentages of carposporophytes and tetrasporophytes were maximal in April (37%) and June (57%), respectively. Maximum growth in plant length, dry weight, and hook number coincided with the tetrasporophyte reproductive peak in the field. In culture, carpospore release, sporeling growth and reproduction were affected by environmental factors such as daylength, temperature, and salinity. The liberation of carpospores was maximum under continuous light and at a combination of $15^{\circ}C$ and $10\;{\mu}mol$ photons $m^{-2}\;s^{-1}$. Maximum growth of tetrasporophyte sporelings occurred at a combination of $20\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and $25^{\circ}C$. However, the growth of gametophyte sporelings was maximal under $40\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and in a combination of $20^{\circ}C$ and 35 psu. The tetrasporophyte sporelings were grew faster than gametophytes, indicating that gametophyte- and tetrasporophyte-sporelings have different physiological responses to irradiance and temperature. Tetrasporangial branches and cystocarps of C. hypnaeoides were produced from carpospores and tetraspores within 1 month, and they were stimulated at high temperature and irradiance levels. In conclusion, C. hypnaeoides should be seeded using carpospores during early winter (November-December) because cystocarps are easily identified by fishermen, and tetrasporophytes grow faster than gametophytes.