• 동력기계공학회지
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• 제21권5호
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• pp.20-28
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• 2017

The steady-state, incompressible and three-dimensional numerical analysis was performed to investigate the flow fields around the seabed tiller used for soil improvement in coastal fisheries and the pulling force and buoyancy generated by tiller operation. The turbulence model used in this study is a realizable $k-{\varepsilon}$. As a results, at a stationary current or a current speed of 1.2 knots, where rotor rotates in a clockwise direction, a typical vortex pair appears near the tip of the rotor except for the edge, and the strength of the vortex pair increases with the number of revolutions of the rotor. The pulling force of the tiller rotating in the counterclockwise direction increases with the number of revolutions. Also, when the current flows at 1.2 knots and the rotor rotates clockwise, the pulling force of the tiller acts on the upstream side irrespective of the number of rotations of the rotor, so that no force is applied. The buoyancy of the tiller acts on the seawater surface if the flow direction inside the rotor is the same as the direction of rotation of the rotor, regardless of the current velocity, otherwise it acts on the seabed.

• 한국초지조사료학회지
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• 제11권1호
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• pp.6-11
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• 1991

Perennial ryegrass 유식물체의 가을철 생육과 1변초의 개처중 및 수량구성요소와의 관계를 검토하여 월동성을 나타낼 수 있는 형질을 션발하고 품종을 분류하고자 하였다. 1. 1 번초의 척체중은 유식물체의 개체당 경수와 유의힌 정상관을, 초세와는 유의한 부의 상관을 나타내었다. 2. 1번초의 개체중은 출수경중, 개체당경수, 영양경수, 출수경수, 1 경중 및 출수율과 유의한 정상관이 인정되었다. 3 .상대경수출현솔이 낮은 품종은 가을철에 분얼의 발생이 많으며 상대경수출현율이 높은품종은 봄철에 분얼의 발생이 많은 특성을 나다내었다. 4 .상대경수출현율당 개체중은 1번초의 개체중, 초장, 출수정중, 개체당 경수, 출수경수, 1 경중 및 출수율과 유의한 정상관을 나타내었다. 5 .상대경수출현율당 개체중에 의하여 2품종군으로 분류되었다 즉, 상대경수출현율당 개체중이 1.0 이 상의 품종에는 7 개 품종이, 1. 0 미만의 품종에는 9 개품종이 포함되었다. 6 상대경수출현율당 개체중에 의하여 분류된 품 종군에서는 수량구성요소의 차이가 인정되었다.7 .상대경수출현율당 개체중은 월동성을 나타내는 유효한 형질이라고 생각되었다.

• Journal of Biosystems Engineering
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• 제29권2호
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• pp.109-120
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• 2004

To obtain basic information for precision agriculture, spatial variability of rice growth condition was evaluated in 100m ${\times}$100m paddy field. The rice growth condition of four hundred locations in the field were investigated to analyze the spatial variability of their properties ; SPAD, plant length and tiller number. Geostatistical analysis was carried out to examine within-field spatial variability using semivariograms and kriged maps as well as descriptive statistics. Descriptive statistics showed that the coefficient of variation for SPAD, plant length, and tiller number exceeded 5.70 %, suggesting a relatively high variability. Geostatistical analysis indicated a high spatial dependence for all the properties except for the second tiller number. The range of spatial dependence was about 20 m for SPAD, plant length, and tiller number. Based on the results of spatial dependence, kriged maps were prepared for the properties to analyse their spatial distribution in the field. The results reflected the history of field management. In conclusion, the need for site-specific field management and possibility of precision agriculture were demonstrated even in an almost flat paddy field.

• 생명과학회지
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• 제7권1호
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• pp.59-65
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• 1997

In this experiment, gene actions were analysized for seven barley parents in order to obtain basic information on their genetic improvement by diallel crosses. The results obtained were summarized as follows. In analysis of variance, additive, dominant, maternal and reciprocal effects were observed significantly for culm length, tiller number, number of spiked per plant, culm diameter, awn length, leaf width, number of grains per spike, and 1000 grain weight. Over-dominance was shown by Vr-Wr graphic analysis in five characters such as tiller number, number of spikes per plant, length of flag leaf, number of grains per spike, and 1000 grain weight, and partial dominance in four characters such as culm length, culm diameter, awn length, and leaf width. Component of genetic varience analyzed for four characters such as culm diameter, awn length, length of flag leaf, and leaf width showed that additive effects were higher than dominant effects. Culm length, tiller number, number of spikes per plant, number of grains per spike, and 1000 grain weight showed dominant effects higher than additive effects. The narrow-sense heritability for awn length, leaf width, and number of grains per spike showed high values as more than 0.62, while broad-sense heritability for culm length, number of spikes per plant, culm diameter, awn length, leaf width, number of grains per spike, and 1000 grain weight showed high values as more than 0.65.

• 한국작물학회지
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• 제37권2호
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• pp.141-148
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• 1992

화본과 청예작물의 예취후 재생시 식물호르몬의 반응을 구명하기 위하여 수수와 진주조에서 각각 생육 특성이 다른 두 품종씩을 선택하여 줄기신장기와 개화기에서 예취한 후 식물생장조절제 IAA, GA, Kinetin을 처리하여 나타난 재생반응을 조사 하였다. 1. Kinetin 처리는 품종과 예취시기에 관계없이 모두 분얼수을 증가시켰으나 재생건물중은 처리에 따른 재생 생육의 저조로 감소되었다. 그러나 수수에서 지하부가 수분 과다스트레스를 받아 분얼의 재싱이 나쁠 때 Kinetin의 처리는 분얼수 및 엽신장을 증가시켰고 이에 따라 수수의 재생건물중도 증가되었다. 반면 IAA의 처리는 무처리와 차이가 현저하지 않았다. 2. GA 처리는 모두 재생분얼의 생성을 억제하였다. 수수에서 재생력이 약한 P931의 GA에 의해 분얼을 확보하지 못해 거의 고사하였고 재생력이 좋은 Jxu-sue은 분얼은 확보하였으나 GA에 의해 도장하는 2차적 효과를 나타내었다. 진주조에서도 GA 처리에 의해 신생분얼의 발생은 억제되었는데 특히 GA는 상대적으로 기존분얼의 발생은 억제되었는데 특히 GA는 상대적으로 기존분얼의 신장을 증가시켜 신생분얼의 발생을 더 억제하였다. 3. 수수와 진주조의 예취후 저장탄수화물 함량 변화를 보면 줄기신장기 예취에서는 재생 초기 재생분얼의 생성으로 감소하였다가 재생분얼의 광합성이 재개됨에 따라 예취 후 7일 째부터 증가 하였다. 그에 반해 개화기는 재생원기의 노화에 의해 분얼의 생성과 신장이 느려 저장탄수화물이 소모되는 기간이 예취 후 14일까지 연장되었고 저장탄수화물 함량이 증가속도도 낮았다. 4. 예취 후 수수의 재생에서 GA 처리가 다른 PGR 처리에 비해 저장탄수화물을 많이 감소시켰으며 따라서 수수의 재생 후기의 저장탄수화물 함량의 회복도 불량하였다. 그 반면 진주조에서는 GA 처리에 의해 기존분얼의 신장이 촉진되어 동화작용을 할 수 있는 엽이 초기에 확보됨으로서 재생후기 진주조의 저장탄수화물 함량은 양호하게 증가되었다. 5 수수와 진주조 모두 재생건물중은 재생초기 탄수화물의 소모량과는 상관관계가 없었고 재생건물중이 분얼수와 예취후 7일간의 초장과 높은 상관관계를 가져 예취 후 재생은 예취시 저장탄수화물 함량보다 그 재생원기의 활력이 중요하였다. 특히 진주조에서는 개화기가 줄기신장기보다 재생분얼원기가 심하게 노화되어 재생분얼수 및 엽신장이 현저히 감소되었고 따라서 예취후 재생건물중도 현저히 감소되었다.

• 한국자원식물학회지
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• 제25권6호
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• pp.745-752
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• 2012

Compared to wide ranges of genetic variation of natural populations, very limited Miscanthus cultivar has been released. This study was the first report on the development of Miscanthus cultivar by means of radiation breeding. Seeds of M. sinensis were initially exposed to gamma rays of 250 Gy for 24 h, generated from a $^{60}Co$ gamma-irradiator. The irradiated seeds were sown and then the highly tiller-producing mutants were selected for this study. Biomass-related parameters including tiller number, plant height, stem diameter, and leaf number were measured. Ploidy level and internal transcribed spacer (ITS) were investigated to characterize the mutants compared to wild type (WT) Miscanthus. Plant height and tiller number were negatively related, where multi-tillering mutants were relatively short after 4 month growth. However stem diameter and leaf number were greater in mutants. All the materials used in this study were diploid, implying that the mutants with greater tiller numbers and stem diameter were not likely related to polyploidization. Based on the sequence of ITS regions, the mutants demonstrated base changes from the gamma irradiation where G+C content (%) was decreased in the ITS1, but increased in ITS2 when compared to WT sequence. ITS2 region was more variable than in ITS1 in the mutants, which collectively allows identification of the mutants from WT. Those mutants having enhanced tillers and allelic variations might be used as breeding materials for enhanced biomass-producing Miscanthus cultivars.

• 한국작물학회지
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• 제60권4호
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• pp.412-420
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• 2015

Even though phosphorus (P) is essential element for plant growth and development, it is not enough for crop production in soil. To breed more P deficient tolerance rice, screening and selection in rice population is needed. We tried to develop more simple and rough screening method for breeding of P deficient tolerance rice. In P deficient condition, tiller number was dramatically decreased among yield components in rice. Though this result, we confirmed tiller number could be the best marker in screening of P deficient tolerance rice. 480 rice genetic resources were cultivated in rice bed tray filled with P deficient soil for four weeks and each dry weight was measured. Among them, the 55 kinds of genetic resource were selected then cultivated in paddy field with 3 fertilizer conditions. Plant dry weight and tiller number in ripening stage were shown significant difference according to P condition. Plant dry weight and tiller number in ripening stage was highly correlated especially in P deficient condition. Furthermore, the tiller number in ripening stage and plant dry weight in rough screening were shown high degree correlation. Though these results, we might expect measuring of plant dry weight after cultivation in rice bed tray filled with P deficient soil could be a simple and effective screening method in selection of P deficient tolerance rice.

• 한국초지조사료학회지
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• 제4권1호
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• pp.13-17
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• 1983

영양생장기(營養生長期)의 형태적(形態的)과 건물수량(乾物收量)과의 관계(關係)를 조사(調査)하여 수량(收量)에 관여(關與)되는 형태적(形態的) 형질(形質)과 품종(品種)의 특성(特性)을 비교(比較), 검토(檢討)하였다. 1. 개체중(건물중(乾物重))은 초장(草長), 엽면적(葉面積) 및 경면적(莖面積)과 유의(有意)한 정상관(正相關)을 나타내어, 개체중의 증가(增加)는 초장(草長), 엽면적(葉面積), 경면적(莖面積)의 상호작용(相互作用)이라고 할 수 있다. 2. 경면적(莖面積)은 건물중(乾物重)을 증가(增加)시키는 중요(重要)한 형태적(形態的) 형질(形質)의 하나라고 생각되었다. 3. 초형지수(草型指數)에 의하여 품종(品種)을 분류(分類)한 결과(結果), 경중형(莖重型)에는 M이 중간형(中間型)에는 Leto, First, Trader, 경수형(莖數型)에는 Bundy, Tammisto가 속(屬)하였다. 4. 경중형(莖重型) 품종(品種)은 초장(草長)이 낮고, 경수(莖數)가 적으나 경건(莖巾)이 두껍고 1 경중(莖重)이 무거웠으며, 경수형(莖數型) 품종(品種)은 초장(草長)이 크고 경수(莖數)는 많으나 1 경중(莖重)이 가벼운 특징(特徵)을 나타 내었다. 5. 경중형(莖重型) 품종(品種)(M)이 다수(多收)를 얻기 위해서는 경수(莖數)를 증가(增加)시키고 초장(草長)을 높게 하는 조건(條件)이 필요(必要)하다고 생각되었다.

• 아시안잔디학회지
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• 제7권1호
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• pp.5-12
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• 1993

This experiment was conducted to study on the morphological change and growth retardation of Korean Lawograss (Zoysia japonica Steud.) under various shading degrees. Dada of plant height, No. of tiller, No. of stolon, No. of rhizome and fresh weight were measured on the l47days after transplanting in 1991. The results are summarized as follows. Plant height was increased at 30% shading degree or over, Maximum plant height was observed at 60% shadeing degree which was 24.2 cm. while full sunlight(control) was most shorted as 10.1 cm. Plant height rapidly was increased as to shading degree increase. The decreasing rate was lower in tiller number and stolon number(top parts of plant) compared with the rhizome number(under ground part) was severely decreased at 30% to 60% of shading. To increase the shading degree, rhizome number was most severely decreased under shading degrees. As degree of shading increase to 30%, 60% and 90%, fresh weight decrease to 66%, 44%, 22% to full sunlight, respectively. Relative growth retadation of Korean lawngrass was decreased by the order of number of rhizome, fresh weight, number of tiller, number of stolon. And these characters were highly significant accord-ing to the different shading degrees.

• 한국초지조사료학회지
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• 제13권2호
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• pp.78-85
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• 1993

This experiment was carried out to select for the varieties with high environmental adaptability in mountainous pastures of Taekwalyong area, and the evaluation was based on the data of varietal differences of dry matter production and yield components in Tall fescue cutting at various developmental stages in growth period of autumn. The results were summarized as follows; 1. The varieties with high number of tillers per plant(NT) showed a high dry weight of plant(DW) in all autumn cuttings. These varieties(Barce1 and Fuego) may be more adaptable to mountainous pastures of Taekwalyon area than other varieties. 2. The number of tillers per plant(NT) was significantly positive correlated with dry weight of plant (DW), but dry weight of tiller(WT) was not significantly correlated with dry weight of plant(DW) in all autumn cuttings. 3. The multiple regression equations of autumn cutting stages with mean dry weight of plant(DW) and number of tillers per plant(NT) can be used to estimate the cutting time to obtain maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT). The maximum mean dry weight of plant(DW) and the highest number of tillers per plant(NT) was estimated at the time of 21 Oct. and 26 Oct, respectively. 4. Dead leaves tended to increase greatly after the 2nd cutting(l4 Oct.) in growth period of autumn. 5. The number of tillers per plant(NT) was an important yield component before tiller density achieved equilibrium, but dry weight of tiller(WT, including dead leaves) was of most significant as a yield determinant after maximum tiller density reached in growth period of autumn.