• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.124-132
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• 2023

This study aimed to cross between Korean and Japanese pure lines of Neopyropia strains to establish cross breeding technology and identify a superior variety that harbors the strength of both parents. Four crossing combinations were tried using three methods, resulting in 1,476 single conchocelis colonies. The three co-dominant Cleaved Amplified Polymorphic Sequence (CAPS) markers (EF-1α/Mse I, TOP2/Mse I, car A/ApaL I) were used to distinguish heterozygotic sporophytes and their maternal lines obtained from the inter and intraspecific cross-fertilization within the wild type of Neopyropia strains. Of the 1,476 colonies, 26.9% (218) were heterozygotes obtained from the nuclear CAPS markers. Their maternal line was clearly confirmed using organelle CAPS marker and chimeric thallus was obtained from crossing experiment of Japanese N. yezoensis (♀) and Korean N. yezoensis (♂). The use of CAPS markers improved the efficiency of crossbreeding by quickly screening heterozygotes and maternal lines in the conchocelis phase, which otherwise required pigmentation mutants as genetic markers.

• ALGAE
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• v.38 no.4
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• pp.283-294
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• 2023

Previous research indicated that free-living sporangial filament keep hollow morph under high-culture density and form bipartite cells under low-culture density, while the following conchospore release was inhibited by high light. Here, we further explored the molecular bases of these affects caused by light and culture density using a transcriptome analysis. Many differentially expressed genes (DEGs) related to carbon dioxide concentration and fixation, photosynthesis, chlorophyll synthesis and nitrogen absorption were upregulated under high-light conditions compared with low-light conditions, indicating the molecular basis of rapid vegetative growth under the former. The stress response- and ion transport-related DEGs, as well as the gene encoding the vacuole formation-brefeldin A-inhibited guanine nucleotide exchange protein (BIG, py05721), were highly expressed under high-density conditions, indicating the molecular basis of the hollow morph of free-living sporangial filaments under high-culture density conditions. Additionally, the brefeldin A treatment indicated that the hollow morph was directly influenced by vacuole formation-related vesicle traffic. Others DEGs related to cell wall components, zinc-finger proteins, ASPO1527, cell cycle and cytoskeleton were highly expressed in the low density with low-light group, which might be related to the formation and release of conchospores. These results provide a deeper understanding of sporangial filaments in Neopyropia yezoensis and related species.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.3
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• pp.5-13
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• 2023

This study aims to assess the water quality of the Eoran and the Imha aquafarm with different aquafarm environments in Haenamn-gun, and analyzed the composition of total amino acids (TAAs) and free amino acids (FAAs) in three Neopyropia dentata cultivars (Yuldo, Supum1 and 2) in two aquafarms. Mean water temperature ranged from 22.9 to 10.9℃ during September to November 2018. In Eoran aquafarm, the water quality analysis showed that NO₂-N was high in September, NH₄-N and COD in October, and NO₃-N, DIN, and DIP in November. In Imha aquafarm, the water quality analysis showed that NH₄-N and COD was high in September, NO₃-N and DIN in October, and NO₂-N and DIP in November. We confirmed the proximate composition, amino acid composition (TAA/FAA) in two auqufarms. In the Eoran aquafarm, the 'Yuldo' cultivar had significantly higher crude lipid content than two other cultivars (Supum 1 and 2). The 'Supum1' cultivar had significantly higher moisture content, whereas the highest content of crude protein, crude lipid, crude ash, and carbohydrates was found in the 'Supum2' cultivar. In the Imha aquafarm, the content of crude lipid and crude ash was highest in the 'Yuldo' cultivar. The highest content of crude protein and carbohydrates was found in the 'Supum1' cultivar, while the 'Supum2' cultivar had the highest content of moisture. The highest concentration of glutamic acid belong to TAAs is observed in all cultivars from Eoran and Imha aquafarm, while all cultivars in two aquafarm also contained higher content of alanine among the detected FAAs.

• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.3
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• pp.19-29
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• 2023

This study investigated effect of water temperature change on the formation and release of conchospores of Neopyropia yezoensis. We observed that conchocelis growth and conchospores formation in oyster shell at labolatory during 7 weeks. In order to investigate the amount of conchospore formation in oyster shells, which was being cultured at 28℃, was moved to 10℃, 18℃, 28℃, and culture during 6 weeks. At 10℃, we observed an average of 127 for 1 week, 127 for 2 weeks, 95 for 3 weeks, 90 for 4 weeks, 76 for 5 weeks, and 75 for 6 weeks. At 18℃, we observed an average of 141 for 1 week, 135 for 2 weeks, 94 for 3 weeks, 153 for 4 weeks, 162 for 5 weeks, and 2 for 6 weeks. At 28℃, we observed an average of 167 for 1 week, 102 for 2 weeks, 148 for 3 weeks, 157 for 4 weeks, 270 for 5 weeks, and 138 for 6 weeks. Conchospores released from the shell grew into a young thalli in the culture for 6 weeks, and the number of ones was counted. The number of young thalli were investigated at 10℃, 0 for 1 week, 189 for 2 weeks, 200 for 3 weeks, 89 for 4 weeks, 56 for 5 weeks and 27 for 6 weeks. At 18℃, It observed 0 for 1 week, 26 for 2 weeks, 546 for 3 weeks, 16 for 4 weeks, 17 for 5 weeks and 154 for 6 weeks. It was not observed at 28℃.