• Korean Journal of Ecology and Environment
• /
• v.47 no.3
• /
• pp.194-201
• /
• 2014

To elucidate which climate factors and what periods affect the time of breeding migration of Gori salamanders (Hynobius yangi), we have investigated relationships between the 5-years breeding monitoring data from 2006 to 2010 which had obtained in both natural and translocated breeding sites at Bongdae mountain, Gijang-gun, Busan-si and the matched climate data obtained from the weather station, approximately 25 km apart from the sites. Mean average and mean lowest temperatures during one month before the first breeding migration were related with the time of first female migration in the translocated site. Mean temperature variation and mean precipitation during 60~120 days before the first breeding migration affected the time of 30% male appearance at the natural site and the time of 30% female appearance at both natural and translocated sites. Climate factors were more closely related with female appearance than male and at the translocated site than at the natural site. Our results show that changes in mean temperature variation and mean precipitation rather than mean average temperature might more significantly affect the breeding migration of salamanders, female breeding migration is more closely related with climate factors, and the salamanders translocated could be more affected by climate changes than those in natural populations.

• Asian-Australasian Journal of Animal Sciences
• /
• v.12 no.6
• /
• pp.850-853
• /
• 1999

Angus postweaning daily gain (PWDG) was analyzed to investigate effects of the heterogeneous variance and the genotypes by sex interaction on prediction of EBVs with data sets of various environmental levels. A whole data (16,239 records) was divided into six data sets according to averages of the best linear unbiased estimator (BLUE) of herd environment. The results comparing prediction models showed that single-trait model is adequate for most of the data sets except for the data set of poor environment for both of the bulls and the heifers where the heterogeneity of variance and the genotypes by sex interaction exists. In the prediction with the data set of the low environment level, the bull's EBVs by single-trait models had high product moment correlations with male EBVs of the bulls by the multitrait model. Whereas the heifer's EBVs had moderate correlations with female EBVs by the multitrait model. This moderate correlation seems to be resulted by the heterogeneity of variance and low heritability of the heifer's PWDG. The prediction models with heterogeneity of variance had little effect on the prediction of EBVs for the data sets with moderate to high genetic correlations.

• Journal of Dairy Science and Biotechnology
• /
• v.39 no.1
• /
• pp.1-8
• /
• 2021

The surroundings of livestock farms, including dairy farms, are known to be a major source of development and transmission of antibiotic-resistant bacteria. To control antibioticresistant bacteria in the livestock breeding environment, farms have installed livestock wastewater treatment facilities to treat wastewater before discharging the final effluent in nearby rivers or streams. These facilities have been known to serve as hotspots for inter-bacterial antibiotic-resistance gene transfer and extensively antibiotic-resistant bacteria, owing to the accumulation of various antibiotic-resistant bacteria from the livestock breeding environment. This review discusses antibiotic usage in livestock farming, including dairy farms, livestock wastewater treatment plants as hotspots for antibiotic resistant bacteria, and nonenteric gram-negative bacteria from wastewater treatment plants, and previous findings in literature.

• The Korean Journal of Malacology
• /
• v.30 no.4
• /
• pp.415-419
• /
• 2014

Inbreeding depression may be an avoidable phenomenon for abalone culture. However, only a few studies were carried out on inbreeding depression. In the present study, to demonstrate inbreeding depression in growth trait of Pacific abalone, H. discus hannai, inbreeding and outbreeding families were produced in 2010. Inbred and outbred families from each experiment were reared in same tank until 10 month for the same breed environment. The individual of inbred and outbred were distinguished by paternity test using microsatellite DNA. The shell length between inbred and outbred families was compared. At the results, significantly higher shell length was observed in the outbred families at 10 mon (P < 0.05). These results indicate that inbreeding depression is obviously observed in growth traits in the first generation of full-sib family of the H. discus hannai.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 1999.11a
• /
• pp.80-101
• /
• 1999

Self-sufficiency ratio of food crops in Korea is estimated under $20{\%}$ in 2010 because total food consumption including feed will be increased. but food grain production will be decreased. It is necessary to maintain the optimum level of food self-sufficiency rate to secure national food demand/supply balance and non-trade and multiple function of agriculture in Korea. It will be possible to produce more food grains having the acceptable quality if the appropriate policy and cropping techniques are developed and practised in future. Breeding for high yielding varieties should be the first target to raise the production potential of food crops . Number of varieties developed during last 30 years is counted as 353 in food crops. New varieties developed in 1990s showed the higher yield potential and the improved agronomic characteristics compared with 1970s and 1980s varieties. But number of varieties planted on the farmer's field over $5{\%}$ of national planting area is less than one third of total varieties developed Breeding efforts to maintain planting area of main food crops should be focussed on consumer's demand and farmer's need. They are the best quality variety in each field of crop utilization, the newly designed variety adapting to changes of natural, rural and cropping environment, and the higher yielding variety. It is also needed to develop new quality crop varieties for inducing more consumption of crop grain produced in Korea for direct food or processing. Development of barley varieties for animal feed. high income soybean varieties, high quality wheat variety. and super yielding rice and barley varieties are also needed to keep or maximize national food production potential. In order to establish the appropriate cropping technique for domestic food security, the strong and continuous interest and financial support on crop breeding are required, and the inter-disciplinary and inter-institutionary researches should be strengthened for successful crop breeding.

• Horticulture, Environment, and Biotechnology : HEB
• /
• v.59 no.6
• /
• pp.875-888
• /
• 2018

Tulip (Tulipa L.) is one of the most important ornamental geophytes in the world. Analysis of molecular variability of tulips is of great importance in conservation and parental lines selection in breeding programs. Of the 70 genic microsatellites, 15 highly polymorphic and reproducible markers were used to assess the genetic diversity, structure, and relationships among 280 individuals of 36 wild and cultivated tulip accessions from two countries: Iran and the Netherlands. The mean values of gene diversity and polymorphism information content were 0.69 and 0.66, respectively, which indicated the high discriminatory power of markers. The calculated genetic diversity parameters were found to be the highest in wild T. systola Stapf (Derak region). Bayesian model-based STRU CTU RE analysis detected five gene pools for 36 germplasms which corresponded with morphological observations and traditional classifications. Based on analysis of molecular variance, to conserve wild genetic resources in some geographical locations, sampling should be performed from distant locations to achieve high diversity. The unweighted pair group method with arithmetic mean dendrogram and principal component analysis plot indicated that among wild tulips, T. systola and T. micheliana Hoog exhibited the closest relationships with cultivated tulips. Thus, it can be assumed that wild tulips from Iran and perhaps other Middle East countries played a role in the origin of T. gesneriana, which is likely a tulip species hybrid of unclear origin. In conclusion, due to the high genetic variability of wild tulips, they can be used in tulip breeding programs as a source of useful alleles related to resistance against stresses.

• Journal of fish pathology
• /
• v.22 no.3
• /
• pp.275-282
• /
• 2009

In this study, effect of mating group, mating dam and mating sire was analyzed using olive flounder Paralichthys olivaceus challenged with Edwardsiella tarda. A challenge test was conducted using 1,708 olive flounder fingerlings obtained through $4{\times}4$ factorial cross from parents selected based on resistant degree. Regarding the means of resistant index, survival rate and days of survival by each mating group, the group(RR) produced by mating among resistant parents were 17.98, 13.77%, and 18.36 days, respectively; the group(SS) produced by mating among susceptible parents were 12.46, 2.71%, and 12.40 days, respectively. This study gives an indication that challenge test results may be successfully used as selection criteria for disease resistance to E. tarda in olive flounder, P. olivaceus.

• Journal of Ginseng Research
• /
• v.44 no.4
• /
• pp.544-551
• /
• 2020

Background: Previous studies have shown the insecticidal efficacy of ginsenosides. In the present study, we aimed to investigate the metabolic mechanism related to the inhibitory effect of panaxadiol saponins (PDSs) against the Asian corn borer Ostrinia furnacalis (Guenee). Methods: Third instar larvae of O. furnacalis were fed normal diets with different concentrations of PDSs for 4 days. The consumption index, relative growth rate, approximate digestibility, and conversion of ingested and digested food were recorded. A targeted gas chromatographye-mass spectrometry assay was performed to detect the profiles of amino acids, fatty acids, and carbohydrates in larvae of O. furnacalis. In addition, the activity of detoxification-related enzymes was determined. Results and Conclusions: PDSs decreased the consumption index, relative growth rate, approximate digestibility, and conversion of ingested and digested food in the 3rd instar larvae of O. furnacalis in a dose-dependent manner. PDSs decreased 15 free amino acids, 16 free fatty acids, and 5 carbohydrates and increased the levels of palmitoleic acid, palmitic acid, and 9-octadecenoic acid in the 3rd instar larvae. The activity of detoxification-related enzymes, such as acetylcholinesterase, glutathione S-transferase, cytochrome P450, carboxylesterase, trehalase, acid phosphatase, and alkaline phosphatase, was reduced in a dose-dependent manner in the 3rd instar larvae exposed to PDSs. These data confirmed the inhibitory effect of PDSs against growth, food utilization, and detoxification in the 3rd instar larvae of O. furnacalis and the potential for using PDSs as an efficient tool for insect pest management for O. furnacalis larvae.

• ALGAE
• /
• v.38 no.2
• /
• pp.141-150
• /
• 2023

Light quality is a common environmental factor which influences the metabolism of biochemical substances in algae and leads to the response of algal growth and development. Pyropia yezoensis is a kind of economic macroalgae that naturally grows in the intertidal zone where the light environment changes dramatically. In the present study, P. yezoensis thalli were treated under white light (control) and monochromatic lights with primary colors (blue, green, and red) for 14 days to explore their physiological response to light quality. During the first 3 days of treatment, P. yezoensis grew faster under blue light than other light qualities. In the next 11 days, it showed better adaptation to green light, with higher growth rate and photosynthetic capacity (reflected by a higher rETR_max = 61.58 and E_k = 237.78). A higher non-photochemical quenching was observed in the treatment of red light than others for 14 days. Furthermore, the response of P. yezoensis to light quality also results in the difference of photosynthetic pigment contents. The monochromatic light could reduce the synthesis of all pigments, but the reduction degree was different, which may relate to the spectral absorption characteristics of pigments. It was speculated that P. yezoensis adapted to a specific or changing light environments by regulating the synthesis of pigments to achieve the best use of light energy in photosynthesis and premium growth and metabolism.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.205-205
• /
• 2022

Sorghum (Sorghum bicolor L.) is a major cereal grain crop of the world and It can be cultivated under high temperature and dry condition with high adaptability to the adverse environment. It is usually eaten with rice in korea and most of domestic sorghum cultivars have been developed by pure line selection and cross breeding. In prior studies, Hybrid cultivar (F1 seed) was known to improve 30-40% in yield and resist to disease and pest than pure line varieties due to hybrid vigor. Therefore, study on the hybrid sorghum is continuously necessary. In korea, hybrid sorghum cultivar have been developed, so we need to find methods seed production technology for supply and commercialization of hybrid seed cultivar. Female inbred line(A-line) and male inbred line(R-line) are needed for hybrid seed production. This study was carried out to investigate growth characteristics and yield of hybrid sorghum according to the seedling period and planting rate between female inbred line(YSA1) and male inbred line (Sodamchal, Miryang 19). When the flowering period of two inbred groups in the process of hybrid seed production is coincides, hybrid seed production is increase. The female inbred line and male inbred lines were cultivated at Daegu in 2021. Two inbred lines were sown at intervals of 3 days and 7days and were evaluated flowering period. As a result, the flowering period of the female inbred line and male inbred lines were matched at the 7days interval. To find out optimal planting rate, two inbred lines were cultivated under different plating rate (4:2, 5:2, 6:2). Yield of YSA1/Sodamchal(F1) was the highest 130(kg/10a) in the 4:2 ratio and yield of YSA1/Miryang 19 was the highest quantity of 139(kg/10a) in the 6:2 ratio. The results of this study could be helpful for hybrid Sorghum seeds production.