• Asian-Australasian Journal of Animal Sciences
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• 제9권2호
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• pp.133-137
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• 1996

Duckweed, an aquatic plant of the family Lemnaceae, is a rich source of protein and also contains cell wall materials. Spirodela, Lemna and Wolffia, the most available species of duckweeds were evaluated in terms of their chemical composition, the rate and extent of digestion of their dry matter(DM) and crude protein(CP) in the rumen and also their acceptability to the cattle. The three species contained CP of 284, 399 and $299g{\cdot}kg^{-1}$ DM, respectively; NDF of 471, 574 and $476g{\cdot}kg^{-1}$ DM, respectively; ADF of 215, 203 and $227g{\cdot}kg^{-1}$ DM, respectively. The rumen digestibilities of DM of the three species for 24 h were 410, 570 and $731g{\cdot}kg^{-1}$ DM, respectively and of CP were 528, 740 and $778g{\cdot}kg^{-1}$ DM, respectively. The rates of digestion of DM of the three duckweeds were 2.22, 3.63 and $5.73%h^{-1}$, respectively and of CP were 5.14, 4.22 and $6.05%h^{-1}$, respectively. Similarly, the extent of digestion of DM were 853, 723 and $926g{\cdot}kg^{-1}$ DM, respectively and of CP were 801, 874 and $943g{\cdot}kg^{-1}$ DM, respectively. Mixed duckweeds as a component of a concentrate mixture were eaten by the cattle at the rate of 10% of their live weights. It may be concluded that the dry matter and crude protein of the available duckweeds wee highly degradable in the rumen and may be fed to cattle mixing with concentrates. For the effective utilization of duck weeds as cattle feed their effect on the rumen digestion kinetics of a roughage diet need to be studied carefully.

• The Korean Journal of Ecology
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• 제9권1호
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• pp.33-40
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• 1986

The distribution of giant duckweed (Spirodela polyrrhiza) and small duckweed (Lemna aequinoctialis) was investigated at lead-zinc mine area and the limiting factors for their distribution were studied by laboratory experiments. The metal investigated of water affected on the growth of giant duckweed and small duckweed. Under filed conditions, both giant duckweed and small duckweed did not persist at more acidic conditions than pH 4.8 or at conditions more than 0.30 ppm of Cd concentration. Giant duckweeds were intolerable, under conditiions with less than 0.30 ppm of Cd and above than 0.07ppm of Zn, but small duckweeds were tolerable under conditions of more than 0.07 ppm of Zn concentration. However, neither can live above 7.50ppm of Zn concentration. These field observations corresponded with the results of the laboratory experiments.

• Journal of Plant Biotechnology
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• 제48권3호
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• pp.156-164
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• 2021

Spirodela polyrhiza, from the Lemnaceae family, are small aquatic plants that offer an alternative plant-based system for the expression of recombinant proteins. However, no turion transformation protocol has been established in this species. In this study, we exploited a pB7YWG2 vector harboring the eYFP gene that encodes enhanced yellow fluorescent protein (eYFP), which has been extensively used as a reporter and marker to visualize recombinant protein localization in plants. We adopted Agrobacterium tumefaciens-mediated turion transformation via vacuum infiltration to deliver the eYFP gene to turions, special vegetative forms produced by duckweeds to endure harsh conditions. Transgenic turions regenerated several duckweed fronds that exhibited yellow fluorescent emissions under a fluorescence microscope. Western blotting verified the expression of the eYFP protein. To the best of our knowledge, this is the first report of an efficient protocol for generating transgenic S. polyrhiza expressing eYFP via Agrobacterium tumefaciens-mediated turion transformation. The ability of turions to withstand harsh conditions increases the portability and versatility of transgenic duckweeds, favoring their use in the further development of therapeutic compounds in plants.

• 한국환경생태학회지
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• 제32권4호
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• pp.425-439
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• 2018

본 연구는 제주도 지역에서 처음 발견된 점개구리밥의 분포와 서식생물상에 대한 점개구리밥의 위해성을 평가하기 위해, 제주도 내 43개 습지 및 하천에서 환경요인과 서식생물상을 조사하였다. 점개구리밥은 43개 중 총 18개 조사지역에서 출현이 확인되었으며, 이들 지역에서는 점개구리밥 외 수생식물의 생물량은 낮은 편이었다. 점개구리밥 등 수생식물과 환경요인에 대한 서식생물상의 영향을 분석하기 위해 SOM(Self-Organizing Map)을 활용한 패턴분석을 실시하였다. 분석 결과, 동물플랑크톤 등 서식생물상은 환경요인보다는 수생식물의 생물량에 대한 영향이 큰 것으로 나타났다. 특히 점개구리밥의 생물량은 부착성 종과 밀접하게 관련되는 것으로 분석되었다. 제주도 내 하천 및 습지는 수원이 일정하지 않고 수위변화가 급격하여 수생식물의 현존량이 적은 점을 감안하면, 제주도 지역의 교란 특성에 비교적 강한 점개구리밥은 서식생물상(동물플랑크톤 등)에게 서식처로서 중요하게 적용될 것으로 판단된다. 더욱이, 점개구리밥의 점유 공간 내 유기물이 서식동물상의 먹이원으로 활용되는 점 등을 볼 때 점개구리밥은 서식처인 동시에 먹이터로의 역할을 수행하고 있는 것으로 보인다. 비록 점개구리밥의 밀생이 그늘 효과 등으로 일부 수생식물의 성장과 발달에 영향을 미치지만, 이것은 부유식물이 수표면에 우점하는 특성 때문이며, 점개구리밥의 위해성이라 판단하기는 어렵다. 결론적으로 점개구리밥은 제주도 지역 내 대부분의 수계에서 확산 및 정착된 것으로 조사되었으며, 서식생물상 및 수중 환경 내 미치는 영향은 적은 것으로 사료된다. 추후 제주도 지역 외 내륙에서의 점개구리밥 분포 및 확산에 대한 모니터링을 수행할 필요가 있다고 보여진다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1168-1176
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• 2004

Intensive animal industries create large volumes of nutrient rich effluent, which, if untreated, has the potential for substantial environmental degradation. Aquatic plants in aerobic lagoon systems have the potential to achieve inexpensive and efficient remediation of effluent, and to recover valuable nutrients that would otherwise be lost. Members of the family Lemnaceae (duckweeds) are widely used in lagoon systems, but despite their widespread use in the cleansing of sewage, only limited research has been conducted into their growth in highly eutrophic media, and little has been done to systematically distinguish between different types of media. This study examined the growth characteristics of duckweed in abattoir effluent, and explored possible ways of ameliorating the inhibitory factors to growth on this medium. A series of pot trials was conducted to test the tolerance of duckweed to abattoir effluent partially remediated by a sojourn in anaerobic fermentation ponds, both in its unmodified form, and after the addition of acid to manipulate pH, and the addition of bentonite. Unmodified abattoir effluent was highly toxic to duckweed, although duckweed remained viable and grew sub optimally in media with total ammonia nitrogen (TAN) concentrations of up to 100 mg/l. Duckweed also grew vigorously in effluent diluted 1:4 v/v, containing 56 mg TAN/L and also modified by addition of acid to decrease pH to 7 and by adding bentonite (0.5%).

• 한국수산과학회지
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• 제15권1호
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• pp.47-51
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• 1982

1981년 여름 폐쇄식 순환사육 장치에서 붉은 Tilapia정어를 잉어정어와 혼합하여 45일간 사육 실험을 행하여 그 성신 결과를 비교 검토하고 또한 호적조건의 노지에서 성장한 붉은 Tilapia정어의 성장과도 비교하여 보았다. 탱크는 대 부분의 실험기각동안 심한 식물성 Plank-ton의 대량 번식으로 수색이 짙은 녹색으로 유가되었으며, 사육장치 일부에는 개구리밥 (Lemma Sp.)과 배옥잠 (Water hyacinth, Eichhornia crassipes)을 번식시켰다. 실험기간 동안 탱크내에서의 총암모니아농도는 최저 3.4ppm에서 최고 11.2ppm까지 나타났으나 대개 $5\sim7ppm$범위로 유지되었다. 실험탱크내에서의 Tilapia의 일일평균 성장률은 1미의 폐사도 없이 $6.51\%$를 나타낸 반면 같은 탱크에서 사육한 잉어는 약간의 폐사와 함께 $3.61\%$로 저조했고, 또한 노지에서 사육한 Tilapia는 $5.77\%$ 를 나타내었다. 이번 사육실험에 사용한 사료는 잉어사료를 주었으며, U. G. F. (Unknown growth factr)를 감안하여 보조사료로서 사육장치 일부에서 번식시킨 개구리밥을 매일 일정양을 공급했다.