• Fisheries and Aquatic Sciences
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• 제26권4호
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• pp.282-293
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• 2023

Nile perch and Nile tilapia are major commercial species in Uganda, and thus require continuous production. However, their production is impacted by anthropogenic activities such as fishing in breeding habitats. The aim of this study was to identify and characterize Nile perch and Nile tilapia fish breeding habitats on Lake Kyoga. Water quality, lake bottom, fish and vegetation type samples were collected from 20 sites in April of 2021 and 2022. Key informant interviews were conducted with experienced fishermen at five fish landing sites. The water quality parameters indicated significant difference within the sites using analysis of variance. Sandy and muddy bottom types were equally spread at 40% each by use of a pie chart. Fish gonads showed no significant difference among the 20 sites. Bivariate correlation analysis of the vegetation types indicated a strong negative correlation with Nile perch while Nile tilapia had a positive correlation. Principal component analysis of the water quality, fish gonads and habitat vegetation components cumulatively contributed 82.5% in characterizing a fish breeding habitat. Four sites for Nile perch and four sites for Nile tilapia were characterized as breeding sites on Lake Kyoga and are recommended for mapping and gazettement as breeding habitats for sustainable fisheries management.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.415-424
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• 2015

This research was conducted to reveal the characteristics of breeding ecology of oriental scops owl (Otus sunia stictonotus) inhabiting in South Korea according to the nest types during the breeding season from march to October for two years (2011 and 2012). Oriental scops owl nested in woodpecker's nest holes (46.1%), natural tree holes (38.5%), and artificial wood boxes (15.4%). These nests were located on following trees: Zelkova serrata, Paulownia coreana, Celtis sinensis, Salix chaenomeloides, Salix babylonica, Fraxinus rhynchophylla, Robinia pseudoacacia and Platanus occidentalis. The hatching success was 91.4%, fledging success was 83.0%, and breeding success was 75.9%. The factors of the breeding failure were falling (57.1%), abandonment (28.6%), hatching failure (7.1%), and others with unknown cause of death (7.1%). According to nest types, the fledging success (69.2%) of woodpecker's nest holes were low and the hatching success (79.2%) of natural tree holes were also low due to hatching failure and abandonment. However, hatching success, fledging success, breeding success were high in the artificial nests as all the eggs hatched and succeeded in fledging. Therefore, we suggested that artificial nests can cover the weaknesses of natural nests as well as increasing the breeding success. However, long-term research on installation place, height, and hole sizes of the artificial nest are required in order to clearly reveal the effects on the breeding success of oriental scops owl.

• 생태와환경
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• 제47권3호
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• pp.194-201
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• 2014

번식 시작 전 어느 기간의 어떠한 기후요소가 고리도롱뇽의 번식이주 시기에 영향을 미치는 지를 파악하고자, 부산시 기장군 봉대산 일대에서 고리도롱뇽의 자연번식지와 인접한 대체번식지에서 2006년부터 2010년까지 5년의 번식기 동안 날짜에 따라 번식지에 출현한 개체들을 기록한 개체군 모니터링 자료와 조사지로부터 약 25 km 떨어진 기상대에서 획득한 기후정보 사이의 상관관계를 분석하였다. 연구결과, 번식 시작 전 약 1달 동안의 평균기온 및 평균최저기온은 대체번식지 내 암컷의 번식이주 시기에 영향을 미쳤으며, 번식 전 2~4달 동안의 겨울철 평균일교차와 평균강수량은 각각 자연번식지의 수컷과 자연번식지와 대체번식지의 암컷의 번식이주 시기에 영향을 미쳤다. 번식이주 시기와 기후 요소와의 관련성은 수컷보다 암컷에서, 자연번식지에서보다는 대체번식지에서 더 높았다. 이러한 연구결과는 년도에 걸친 단순한 평균온도의 상승보다는 겨울철을 포함하는 기간 동안의 평균강수량과 평균일교차의 변동이 유미양서류 번식이주 시기에 더 큰 영향을 미치는 것을 보여준다. 더불어 암컷의 번식이주 시기가 수컷에 비하여 기후요소에 보다 더 밀접하게 관련되며, 특별히 이주된 유미양서류의 개체군들에서 이주시기는 기후요소의 영향을 더 크게 받는다는 것을 보여준다.

• 방사선산업학회지
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• 제5권4호
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• pp.285-295
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• 2011

Mushrooms belonging to macrofungi have been consumed by humans for their nutritional and medicinal values for centuries throughout the world. Mushroom farming is practiced in more than 100 countries of the world, with production increasing at a rate of 7% per annum. High yield and good quality are always the principal goals for agriculturally important crops, including mushrooms. Several breeding methods are employed for strain improvement such as mass selection based on the natural chance mutation and induced mutation (mutation breeding), protoplast fusion technology, cross breeding and transgenic breeding. However, mutation breeding has shown prominent success in crop plant improvement. Though several-hundred mutant crop varieties have been developed around the world, the mutation breeding of mushrooms is limited. This review paper explores the potential application of radiation on the development of mutant varieties of mushrooms for breeding with desired traits such as better quality and productivity.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.193-198
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• 2008

To develop a natural re-seeding technology, the optimum soil incorporation time of Chinese milk vetch(CMV) plant residues, seed persistence in soil, biomass production and subsequent rice yield were determined from 2005 to 2007 in rice with CMV green manure in southern Korea. Generally, insufficient seedling stand was regenerated with CMV incorporation to the soil at 20 and 25 days after flowering(DAF), while high regeneration of greater than 400 seedlings per $m^2$ was observed at 35 and 40 DAF. High re-seeding stand of CMV incorporated at 35 DAF or later was related with high seed viability and heavy seed weight. Appreciable number of CMV seeds remained 4 month after burial in soil and a good number of CMV seedlings regenerated from this seed bank at rice harvest time in the fall. Based on the relationships among re-seeding number of CMV plants, seed weight and seed viability, CMV plants should be incorporated into the soil 35 DAF(May 30) or later when CMV seeds were sufficiently matured. The natural re-seeding stand for the 3-year trials was stable ranging from 437 to 700 plants per $m^2$ and the biomass production was sufficient to supply nitrogen for rice growth. The use of re-seeding CMV plant can produce similar rice yield like that of rice without CMV green manure.

• 환경생물
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• 제35권2호
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• pp.134-142
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• 2017

난도는 괭이갈매기 번식지 중 하나로 천연기념물로서 보호되고 있다. 본 연구에서는 난도에서 번식하는 괭이갈매기 개체군과 서식지 현황을 파악하기 위해서 2015년 7월부터 11월까지 조사하였다. 둥지 밀도를 이용하여 번식 개체군을 산정하였다. 괭이갈매기는 $1m^2$당 평균 0.51쌍이 번식하고 있었으며 약 26,760개체가 난도에 번식하고 있는 것으로 추정된다. 난도의 우점식생은 돌피와 개밀이었으며 괭이갈매기가 은신처나 둥지장소로 이용하고 있었다. 번식기간 중 괭이갈매기의 주된 먹이는 멸치 (48%)로 보인다. 그 밖에 난도에서 번식하는 바닷새로는 슴새, 가마우지, 바다제비 등을 확인할 수 있었다.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.45.2-45.2
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• 2007

See Full Text

• 한국육종학회지
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• 제42권4호
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• pp.381-389
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• 2010

한국의 전역에 자생하는 달래를 대상으로 육종 및 재배의 기초 자료를 얻고자 자생환경과 자생특성을 조사하였다. 자생지의 광환경은 121개의 자생지 중에서 반음지가 66개의 54.6%, 음지가 42개의 34.7%, 그리고 양지가 13개의 10.7%의 순이었다. 자생하는 장소는 밭 주변이 55개의 45.4%, 사찰 주변이 34개의 28.1%, 산 주변이 22개의 18.2%, 하천변이 7개의 5.8%, 그리고 도로변이 3개의 2.5%의 순이었다. 자생지는 $33^{\circ}N{\sim}38^{\circ}N$, $126^{\circ}E\sim129^{\circ}E$ 범위의 모든 지역에 널리 분포하였다. 자생지의 지역적인 분포를 보면 충청북도와 경상북도에 많았고 전라북도와 전라남도에는 적었다. 자생양상은 개체와 개체 사이가 밀착하여 집단을 형성하였다. 생육은 자생지역에 따라 다소 차이가 있었으나 대체로 맹아기는 9월과 익년 3월이었으며, 월동 후 3월부터 4월까지 생장하였고 추대하는 개체는 없었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권10호
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• pp.1507-1514
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• 2017

Objective: The Bashang Long-tail chicken (BS), an indigenous Chinese breed, is considered cold tolerant. We selected BS, the Rhode Island Red (RIR), and their reciprocal crossbreds for the present study. The objectives were: i) to validate whether BS is cold tolerant and whether egg production and cold tolerance of crossbreds could be improved; and ii) to determine the physiological characteristics that underlie cold tolerance and favorable egg production performance in cold environments. Methods: A total of 916 chickens were reared in warm and natural cold environments (daily mean ambient temperature varied from $7.4^{\circ}C$ to $26.5^{\circ}C$ in the warm environment and from $-17.5^{\circ}C$ to $27.0^{\circ}C$ in the cold environment). To investigate their adaptability to the cold environment, the egg production performance and body weight were monitored and compared between breeds and environments. The cloacal temperature and serum biochemical parameters were monitored to reveal the physiological characteristics underlie cold tolerance and favorable egg production performance in the cold environment. Results: The warm environment experiment showed that RIR had the highest egg production performance, and that the reciprocal crossbreds had a higher egg production performance than BS. While in the cold environment RIR had the lowest egg production performance, and the reciprocal crossbreds had a higher egg production performance than BS. In the cold environment BS and reciprocal crossbreds had higher triiodothyronine, tetraiodothyronine levels than RIR. At 35 and 39 wk of age, when the ambient temperature was extremely low (varied from $-20^{\circ}C$ to $0^{\circ}C$), serum glucose, follicle-stimulating hormone, luteinizing hormone, estradiol of BS and crossbreds were higher than RIR. Conclusion: Bashang Long-tail chicken has a favorable cold tolerance ability. Crossbreeding with RIR and BS is an effective way to develop cold tolerant chickens with improved egg production performance.

• Asian-Australasian Journal of Animal Sciences
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• 제19권11호
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• pp.1524-1528
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• 2006

A total of 437 animals, comprising lambs aged between 3 and 12 months and adults of either sex of Muzaffarnagari sheep maintained at the Central Institute for Research on Goats, Makhdoom, Farah, Mathura, India were screened to assess the prevalence of Haemonchus contortus infection following natural infection and to identify the various factors affecting faecal egg count (FEC) and packed cell volume (PCV) of ewes and their genetic control. The relationships between FEC, PCV and body weight were also estimated. The prevalence rate for H. contortus infection in the flock under study was 15.7% indicating much lower occurrence of worm infection in lambs up to one year of age. On the other hand, a large proportion i.e., 67.7% of sheep was refractive to natural H. contortus infection. The random effect of sire significantly contributed (p<0.01) variation in log-transformed FEC (LFEC) of ewes. The season of birth had a significant (p<0.01) effect on LFEC of ewes. The lactating ewes had significantly (p<0.01) higher faecal egg counts compared to dry and pregnant ewes. The linear regression effects of the age of ewes on LFEC of animals were significant (p<0.01) in the present study. The heritabilities of LFEC, PCV and body weights of ewes during the course of infection were moderate to high in magnitude and ranged from 0.24 to 0.47. The LFEC of ewes was significantly (p<0.05) and negatively correlated with PCV at both genetic and phenotypic level. The genetic and phenotypic relationships between LFEC and body weights of ewes were -0.26 and -0.06 for this breed. The genetic correlation of PCV and body weight of ewes was positive and high (0.58) and statistically significant (p<0.05) but it was negatively correlated (-0.01) with body weight at the phenotypic level.