• Ocean and Polar Research
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• 제42권3호
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• pp.225-231
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• 2020

The aim of this study was to examine optimal induction method for carpospore release from Agarophyton vermiculophyllum cystocarps for seedling production. We tested the effects of environmental factors on carpospore release by using five different induction methods; spontaneous, desiccation, low temperature, desiccation+low temperature, and osmotic shock. Also, carpospores release was estimated at three temperatures (20, 25, and 30℃), and then under combinations of three day lengths (8, 12, and 16h) and two irradiances (30 and 60 μmol photons m^-2 s^-1), after pretreatment at desiccation+low temperature for 2 hr. The number of carpospores released was between 113 ~ 682 spores /cystocarp/day and it was maximal in the desiccation+low temperature treatment. Optimal environmental conditions for carpospore release of A. vermiculophyllum were 25℃, 16 h, and 60 μmol photons m^-2 s^-1. The present results suggest that massive carpospores for seedling production of A. vermiculophyllum could be obtained under a combination of 25℃, 16 h, and 60 μmol photons m^-2 s^-1 after pretreatment in the desiccation+low temperature.

• Fisheries and Aquatic Sciences
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• 제4권4호
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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.

• 한국수산과학회지
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• 제44권3호
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• pp.290-297
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• 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
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• 제18권2호
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• pp.177-181
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• 2003

Variation in seasonal growth, phenology and periodicity in spore shedding in Polysiphonia platycarpa $B{\oslash}rgesen$ occurring on the coast of Visakhapatnam, India, have been described to know the growth behaviour, reproductive periodicity and spore producing capacities. This alga occurs for a short period from December to May in the intertidal region of the Visakhapatnam coast, showing maximum growth during January/February. Tetrasporophytic, carposporophytic and antheridial plants were observed in all months of their occurrence in the field. But the vegetative plants were not seen in January and February and all the plants collected were reproductive. The tetraspore and carpospore shedding was observed during all the six months of their occurrence.

• ALGAE
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• 제30권1호
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• pp.1-13
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• 2015

A new macroscopic riverine red algal species, Lemanea manipurensis sp. nov. (Batrachospermales) is described from Manipur in northeast India. It has a sparsely branched, pseudoparenchymatous thallus with a single, central axial filament that lacks cortical filaments. Spermatangia occur generally in isolated, low and indistinct patches or form an almost continuous ring around the axis. Carposporophytes project into the hollow thallus cavity without an ostiole. The most striking morphological feature is the carposporophyte with very short gonimoblast filaments having cylindrical, narrow and sparsely branched sterile filaments, the terminal cell of each branch with a single, large, elongate carpospore. The widely distributed L. fluviatilis has spherical carpospores in long branched chains. Phylogenetic analysis of rbcL sequence data and comparison with other Batrachospermales clearly show that our specimens do not align with other species of Lemanea and Paralemanea investigated thus far. Five specific names attributed in previous literature (1973-2014) to Lemanea from Manipur, L. australis, L. catenata, L. fluviatilis, L. mamillosa, and L. torulosa are rejected until critical anatomical and molecular evidence is available for specimens from the Manipur river systems. Taxa referable to Paralemanea were not confirmed for India in this study. In view of the high demand for food and medical uses of L. manipurensis in northeast India, conservation measures are needed for its long term survival. The present paper constitutes the first combined morphological / molecular study on a freshwater red alga from India.

• 생명과학회지
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• 제14권2호
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• pp.331-338
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• 2004

동해안 고유종인 긴잎돌김의 발생과 성숙, 생활사 등 생태에 관한 연구가 시행되었다. 긴잎돌김은 10월 초순에 발생하여 11월 말경에 성성숙이 시작되어 수정에 의해 과포자낭이 형성되고 과포자가 방출되었다. 3월 말경에 엽체가 소멸되었으며 이후 사상체, 각포자기를 거쳐 10월에 엽체가 발아하였다. 긴잎돌김의 특징으로 엽체는 피침형, 모근은 심장형이 대다수를 차지하였으며 거치상돌기가 없고 유성세대과정을 가지며 선명한 과포자낭무늬를 가진다. 암ㆍ수배우체에 있어 엽체와 엽폭비율은 성성숙기인 12월에 각각 5.6∼7.4 및 4.9∼7.3이였다. 1월에는 3.3∼4.8, 4.2∼4.8이였다. 개체수 변화는 10월 초순에 방형구(30${\times}$30 cm)내에 평균 5개체, 12월에는 238개체, 3월 중순에 15개체로 변화되었다. 성 분화가 시작되는 12월 초순에 암ㆍ수배우체 및 영양세포의 비율은 각각 31%, 47%, 22%였으며 완전 성숙된 12월 중순은 암ㆍ수배우체만 69.4% 및 30.6%였다.