• Korean Journal of Fisheries and Aquatic Sciences
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• 제33권3호
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• pp.219-224
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• 2000

Reproductive biology of the naked-headed goby, Faronigobius gymnauchen was investigated by means of histological methods. The ovary was consisted of several ovarian lamellae and the oogonia originated from the inner surface of the ovarian lamella. The testis was seminiferous tubule One in internal structure. Seminiferous tubule was consisted of many testicular cysts which contained numerous germ cells in a same developmental stage. The size of group maturity was 4.5 cm intotal length. Gonadosomatic index(GSI) of the female and male was the highest in June and July, respectively. Reproductive cycle could be classified into the growing ($January{\~}March$), maturation ($April{\~}May$), ripe and spent (June{\~}July$), and recovery and resting ($August{\~}December$). Oocyte development was group-synchronous, and yolk nucleus was observed in the early growing oocyte.

• Journal of The Korean Society of Grassland and Forage Science
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• 제18권1호
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• pp.49-54
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• 1998

This experiment was carried out to investigate effect of plant density on yield and quality of corn at the forage experimental field, grassland and forage division, National Livestock Research Institute, RDA, Suwon eom 1996 to 1997. The two corn hybrids, P 3352 and G 4743, were grow at plant density of 67,000; 71,000; 83,000 ; 89,000 and 95,000 plantha in 60,70 and 75-an spaced rows. At the low density, plant and ear height were decreased but ear length and weight were increased. Plant density had little effect on the tasseling date, silking date and ear ratio to total dry matter. The total dry matter yield of two hybrids was increased kom 15,294 to 18,996 in P 3352 hybrid and 15,881 to 21,386kglha in G 4743, respectively, by decreasing plant density. Plant density had little effect on the ADF(acid detergent fiber), NDF (neutral detergent fiber) and CP(crude protein) concentrations, but the quality of late maturity hybrid, G 4743, was higher than that of early maturity hybrid, P 3352. The result of this study indicate that 67,000 plantlha plant density was recommendable for machanization and maximum DM yield of corn.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제40권5호
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• pp.315-322
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• 2007

Kjellmaniella crassifalia Miyabe is one of the valuable seaweed crops cultured in the Korean coastal waters of the East Sea. Unfortunately recent environmental changes have adversely influenced its growth, prompting the need to develop techniques for species restoration. To obtatin biological information, the growth of the species was monitored for one year. The maximum blade length, $110{\pm}45cm$, was attained in July, and zoospores were released in November. The optimum culture conditions allowing juvenile sporophytes to grow to young blades consisted of $20{\mu}mol/m^2s\;at\;10^{\circ}C$ under which the blade length grew to $1,732.5{\pm}143.3{\mu}m$ in 42 days. Sporangial sori started to form in September, reaching 85% maturity in November and 89% maturity in December. Examining the growth of the species according to depth, the individuals growing at 5 meters grew the most, reaching a blade length of $75.9{\pm}18.9cm$ in August.

• Korean journal of applied entomology
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• 제50권4호
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• pp.379-382
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• 2011

The damage rates of peach pyralid moth(Dichocrocis punctiferalis), which damages the chestnut fruits, were investigated annually from 1995 to 2010 according to year, region, and maturity. The damage rate by D. punctiferalis was the highest (34.5%) in 1998 and was the lowest (17.9%) in 2000. The pattern of the damage rate showed a repeating three-year cycle. There was a negative correlation ($-0.6261^*$) between rainfall and damage rate. There was a positive correlation ($0.5826^*$) between temperature and damage rate. The average damage rate of all surveyed regions was 22.2%. Of the surveyed areas, Hapcheon had the highest at 27% and Hamyang had the lowest at 15.0%. The damage rate of chestnut fruit depending on the maturity was 26.1% in an early maturing cultivar (Dantaek), and 19.3% and 21.1% in a late maturing cultivar (Eungi) and a medium maturing cultivar (Chukpa), respectively.

• Korean Journal of Organic Agriculture
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• 제16권3호
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• pp.299-308
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• 2008

In this study, the effect of commercial organic growth medium amended with different ratios of vermicast on the growth of rice seedlings. The amended ratios of vermicast were 0% (control), 5%, 10%, 20% and 40%, respectively. A bioassay with two rice varieties (Chucheng and Black) was conducted to assesses the amendment effect of vermicast on the seedling growth in two potting methods. In potting treatment, the Chucheng variety with late maturity showed significantly higher values on growth parameters excepted root weight (RW) up to 20% and Black variety with early maturity up to 10% amended with vermicast, respectively. In floor layering treatment, all of the growth parameters significantly increased up to 5% amended with vermicast in both rice variety. The seedling growth of rice in floor layering treatment attained the highest values at lower amended ratios of vermicast than those of potting treated only, it may correspond with increased uptake of nutrient by elongated root grown under the layering amendment of vermicast. Vermicasts can be used as soil amendments or components of plant growth medium for seeding organic agriculture.

• Journal of Environmental Science International
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• 제30권1호
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• pp.77-85
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• 2021

This study was carried out to establish optimal conditions for breaking dormancy of Agastache rugosa O. Kuntze seeds. A series of experiments according to seed maturity and treatment with plant growth regulators were performed to improve germination percentage and synchronize germination of the seeds. In addition, it was conducted to test whether the useful effect of seed treatment before sowing leads to healthy seedling and early vigorous growth. The average seed size was 1.85 mm (length) × 0.82 mm(width). The seed size was much smaller than other vegetable seeds. Seeds colorappeared dark brown, the shape of the seeds was oval and the weight of 1,000seeds was 352.8 mg. The optimum germination temperature was 22℃. Light exposure during germination did not affect germination promotion, suggesting that A. rugosa seeds are a kind of dark germinating seeds. Seed dormancy lasted for 40 days after harvesting, and GA3 treatment of dormant seeds could break dormancy. There were significant differences in germination percentage and rate according to the maturity of seeds. The germination percentage of mature seeds was 10 - 18% higher than that of immature seeds, and germination rate was 2 days faster. GA3 treatment during growth regulator treatment improved germinability, but BAP or ethephone treatment did not. The optimal growth regulator concentration of for germination was the combination treatment of 100 mM GA3 ＋ 100 mM BAP.

• Fisheries and Aquatic Sciences
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• 제26권6호
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• pp.380-392
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• 2023

Groupers (Family Epinephelidae) are commonly caught in data-poor small-scale multi-species fisheries for sale on both export and domestic markets. This study presents data on the species composition and size/life-stage structure of Epinephelus spp. groupers caught by small-scale fishers and sold locally in the Indonesian province of South Sulawesi. Data were collected from fishing ports and local markets at 12 sites representing the three seaways around South Sulawesi (Makassar Strait, Flores Sea, Gulf of Bone). Each specimen (n = 3,398) was photographed alongside an object of known length, and total length (TL) was obtained using the Rapid Scaling on Object (RASIO). Of the 23 species identified, four (Epinephelus areolatus, Epinephelus ongus, Epinephelus quoyanus, and Epinephelus fasciatus) collectively comprised 69% of the catch, while the 13 least abundant species contributed less than 5%. The catch was dominated (67%) by the subadult life-stage, with just under 20% in the adult class. Juveniles dominated the catch of Epinephelus fuscoguttatus, a valuable export commodity. Observations of early maturity as well as the sizeable gap between length at first capture (Lc) and length at first maturity (Lm) indicate recruitment overfishing of most species, with the notable exception of Epinephelus rivulatus. The proportion of adult fish was low (≈5%-30%) for the twelve most abundant species (E. areolatus, E. ongus, Epinephelus quoyanus, E. fasciatus, Epinephelus coioides, Epinephelus faveatus, Epinephelus sexfasciatus, Epinephelus maculatus, Epinephelus bleekeri, Epinephelus corallicola, E. fuscoguttatus, Epinephelus polyphekadion). For two moderately abundant species (E. faveatus and E. malabaricus), TL < Lm for all specimens. The limited data available indicate spawning ratio is lower than reported from deep-water fisheries of E. areolatus and E. coioides. The results call for targeted research to fill knowledge gaps regarding the biology and ecology of groupers exploited mainly for domestic markets; highlight the need for species-level data to inform management policies such as minimum legal size regulations; and can contribute towards species-level status assessments.

• Development and Reproduction
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• 제18권2호
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• pp.99-106
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• 2014

Fish larvae are immediately exposed to microbes from hatching to maturation of their lymphoid organs, therefore effective innate mechanisms is very important for survival. However, the knowledge of the development of immune system in fish is limited and in demand now. In vertebrates, recombination-activating gene 1 (RAG-1) and immunoglobulin M (IgM) have been considered as very useful markers of the physiological maturity of the immune system. In this study, the expression of the both genes was assessed throughout the early developmental stages of olive flounder larvae (5-55 dph) and used as markers to follow the development of immune system. RAG-1 and IgM mRNA expression was detectable at 5 dph and remained so until 55 dph. These patterns of expression may suggest that the olive flounder start to develop its function around 5 dph. Tissue distribution was found that both genes mRNAs are only expressed in the immune-related organ such as spleen, kidney and gill. The early detection of IgM mRNA led to the investigation of its presence in oocytes. Both RAG-1 and IgM mRNA transcripts were detected in unfertilized oocytes, suggesting that they are maternally transferred. The biological significance of such a phenomenon remains to be investigated.

• The Korean Journal of Physiology and Pharmacology
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• 제19권2호
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• pp.131-139
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• 2015

This study analyzed the differences in aerobic and anaerobic exercise ability and growth-related indicators, depending on the polymorphism of the ACE and the ACTN3 genes, to understand the genetic influence of exercise ability in the growth process of children. The subjects of the study consisted of elementary school students (n=856, age $10.32{\pm}0.07yr$). The anthropometric parameters, physical fitness and growth factors were compared among groups of the ACE I/D or the ACTN3 R577X polymorphisms. There were no significant differences between the anthropometric parameters, physical fitness and growth factors for the ACE gene ID or the ACTN3 gene R577X polymorphism. However, the DD type of ACE gene was highest in the side step test (p<0.05), and the DD type was significantly higher than the II+ID type (p<0.05) in the early bone age. The combined group of the ACE gene II+ID and the ACTN3 gene XX type significantly showed lower early bone age (p< 0.05). This study did not find any individual or compounding effects of the polymorphism in the ACE I/D or the ACTN3 R577X polymorphisms on the anthropometric parameters, physical fitness and growth factors of Korean children. However, the exercise experience and the DD type of the ACE gene may affect the early maturity of the bones.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제45권2호
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• pp.97-102
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• 2000

This experiment was conducted to investigate the changes of harvest index and the relationship between harvest index and yield determination factors by different planting times in the determinate soybean cultivars, Shinpaldal and Danbaeg. Optimum planting were 23 May in 1995 and 1996. Late planting were 13 June in 1995 and 6 June in 1996. Growth period from planting to physiological maturity (R7) was shortened as planting time was delayed in two cultivars due to shortening of reproductive growth period in Shinpaldal, and of vegetative growth period in Danbaeg. Stem weight was distinctly decreased in late planting compared to optimum planting, but seed weight of both cultivars was not different between planting times. Also, seed number per pod and harvest index were significantly increased in late planting and the high correlation was found between two factors. It was suggested that increase of harvest index in late planting would be related with high assimilate use efficiency due to increase of sink capacity. The results of correlation and principal component analysis for yield determination factors showed that main factor on yield determination was pod number per plant at R5 stage associated with dry matter accumulation during early reproductive growth period, seed number per pod and harvest index were the second factor, and one hundred seed weight was the third factor. The result of this experiment indicated that yield determination in soy-bean was dependent mainly on pod number per plant related to dry matter accumulation by early reproductive growth period, and the increase of seed number per pod and harvest index could compensate for yield decrease by shortening of vegetative growth period in late planting. Such result suggests that optimum planting date can be delayed from mid May to early June in improved soybean cultivars in Korea.