• ALGAE
• /
• v.20 no.4
• /
• pp.295-298
• /
• 2005

The growth of subaerial microalgae on historic buildings or various cultural properties causes discoloration and physico-chemical deterioration of the surfaces. We collected a subaerial chlorophyte, Chlorella sp., from the stone Standing Buddha statue at Jungwon Miruksazi, which is a national treasure of Korea, and found dormant, thickwalled spores with regular pentagonal ornamentation along with the vegetative Chlorella cells. The morphology of Chlorella resting spores was compared to that of the other green algal resting cells. The ornamented spores and smooth-walled vegetative cells revived in 2 weeks in a liquid freshwater medium and started reproduction by autospores. To our knowledge, the ability of Chlorella to form ornamented dormant spores in drought condition was not previously recorded. The ornamentation of spores would supplement taxonomic characteristics of this genus.

• Applied Biological Chemistry
• /
• v.10
• /
• pp.101-105
• /
• 1968

The effect of concentration of carbon and nitrogen sources on the sporulation and the life cycles of three strains of Zygosaccharomyces was investigated. The results are as follows: 1) The good sporulation of Zygosaccharomyces bisporus, delbruekii, and Z. steineri was obtained on solid medium containing 0 to 0.001% of nitrogen and 10 to 20% of glucose. The high content of nitrogen was detrimental to sporulation and asci were formed under 0.01% of nitrogen. 2) It is widely accepted that the life cycle of Zygosaccharomyces proceeds in the following way: Ascospore...Vegetative cells...Conjugation of vegetative cells...Sporulation...Ascopores But zygotes of Z. bisporus proceeded to vegetative cells when transfered to the suitable medium for vegetative reproduction, and then formed asci.

• ALGAE
• /
• v.17 no.3
• /
• pp.161-170
• /
• 2002

The vegetative and reproductive features of Grateloupia filicina (Lamouroux) C. Agardh (Cryptonemiales, Halymeniaceae) from different parts of the Indian Coast were studied. The plants grow in wide range of habitats and showed a lot of morphological variations. The development of the thallus is multiaxial type and the medullary region is composed of irregular, branched and stellate shaped cells. The gametophytic plants are dioecious and the male plants are smaller compared to female plants. The carpogonial branch is two-celled and formed on an a accessory branch system known as ampulla. Cystocarps are spherical to sybspherical with distint ostioles and scattered on the thallus surface. Tetrasporangia are common and tetraspores are either cruciate or decussate. Bisporangia are occasionally encountered. Our study suggests occurrence of two intraspecific taxa of G. filicina i.e.: var. luxurians and var. filinina from India coast.

• 한국생태학회:학술대회논문집
• /
• 2002.08a
• /
• pp.133-139
• /
• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filed by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• The Korean Journal of Ecology
• /
• v.25 no.4
• /
• pp.267-273
• /
• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filled by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• Fisheries and Aquatic Sciences
• /
• v.1 no.1
• /
• pp.1-6
• /
• 1998

Morphology and reproduction of the two similar Acrosorium species, A. polyneurum and A. yendoi, were studied based on specimens collected from Korea. The morphology of the former species was very variable, depending on its habitat, and in some cases shown superficial resemblance to that of A. yendoi. Also its reproductive structures were essentially the same as those of the latter. However, the two species appear to be distinguished by some vegetative features found in fully developed stage, such as thallus size, vein structures and branching pattern. Acrosorium polyneurum has comparatively large thallus (6-8cm) with three to five cell-layered macroscopic veins, together with palmately dichotomously branching, whereas A. yendoi is of smaller thallus (3-6cm) with microscopic veins of one to three cell layers, and shows irregularly dichotomously or pinnately branching. This result, together with recent data based on PCR technique, suggests that the two entities are distinct.

• Journal of Forest and Environmental Science
• /
• v.32 no.2
• /
• pp.113-119
• /
• 2016

The long lived iteroparous conifers produce male and female gametophyte for hundreds of years once they reach the reproductive stage, however, the production of seed is not frequent. This phenomenon of infrequent seed production in conifers is yet to be understood. An attempt to study this change in cone production in Cedrus deodara of Western Himalayas -a species reported to be mainly monoecious and rarely dioecious has been made. The observations recorded on selected trees of flowering/fruiting stage for four years at four different locations have shown the species to be dioecious with higher percentage of female trees during good seed year but with no definite or predictable pattern of reproduction in the trees. A decline in production of female trees was witnessed at all but one location immediately year after reaching the maximum (good seed year). The phenomenon of seed production has been observed to be cyclic and site specific. A change in the sexual behavior of the trees from male to female or vice-versa, male or female turning monoecious or vegetative and vegetative coming to reproductive was unpredictable.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.16 no.3
• /
• pp.493-502
• /
• 2021

A Vegetative Propagation by Runner(VPR) Algorithm-based on MPPT Algorithm that can track MPP by adapting to external environmental changes is presented. VPR is an optimization algorithm that mimics the plant ecology of movement and reproduction based on vegetation organs. The VPR algorithm includes a procedure for aging and a procedure for searching the surroundings by rhizomes. Accordingly, it is possible to continuously search around the optimal point. Therefore, the VPR-based MPPT algorithm can continuously search for an optimal point by adapting the changes in the external environment in the process of executing the MPPT algorithm. In this paper, we analyzed the performance of the VPR-based MPPT algorithm by a number of simulations. In addition, the superiority of performance was compared by performance comparison in the same environment as MPPT algorithm based on PSO.

• 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.

• ALGAE
• /
• v.18 no.2
• /
• pp.107-119
• /
• 2003

Neosiphonia is separated from the traditionally well known genus Polysiphonia (Rhodomelaceae, Rhodophyta) and 12 species includes in Korea. In this study, the vegetative and reproductive developments of two Neosiphonia species, N. decumbens (Segi) M.S. Kim et I.K. Lee and N. harlandii (Harvey) M.S. Kim et I.K. Lee, are reinvestigated. N. decumbens is diagnosed by following combination of the characters: plants 1-3 cm high, dwarf, decumbent, main axes indistinct, irregularly branched in dichotomous manner, and alternately or secundly ramified with wide angles above. N. harlandii is distinguished by the features: plants 4-8 cm high, usually solitary and saxicolous, erect, densely corticated at base of distinct main axes, rather irregularly alternate in branch, and with cicatrigenous branchlets developed numerously on every part of frond. The two species share typical characteristics of the genus Neosiphonia, such as a base attached by unicellular rhizoids, cut off by cross wall, pericentral cells in 4, trichoblasts moderately developed near the apex of branches, leaving persistent scar-cells, tetrasporangia arranged in a spiral series, procarps with 3-celled carpogonial branch, and spermatangial branches arising as a primary branch of trichoblast. Taxonomy of the two Neosiphonia in regard to Polysiphonia is discussed.