• Journal of Plant Biotechnology
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• 제6권3호
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• pp.193-197
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• 2004

In vitro multiplication of Curculigo orchioides was achieved by direct somatic embryogenesis in young leaf segments. Immature leaf segments of about 0.5 cm in length were cultured on MS medium supplemented with different concentrations of BAP (2-10 $\mu{M}$) or Kin (2-10 $\mu{M}$). Optimum response in terms of per cent cultures responding (89%) and the number of embryos per explant (16) were observed on MS medium supplemented with 8 $\mu$M BAP. The emergence of several somatic embryos on the adaxial side of the leaf segments was observed one month after the culture. Germinated somatic embryos were grown up to about 1.5 cm length before transferring to maturation medium. For maturation, the individual embryos were isolated and transferred to MS medium supplemented with BAP (5 $\mu{M}$) and NAA (0.5 $\mu{M}$). The plantlets emerged from the embryos were transferred to soil containing 1 peat: 1 sand with 90% success. The embryos were formed directly on the leaf segments without any callus phase. Direct regeneration of somatic embryos is important for the conservation of this endangered species, as rare somaclonal variants are likely to arise than from indirect regeneration.

• 한국작물학회지
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• 제43권1호
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• pp.49-53
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• 1998

Direct-seeding has major advantages such as labor and cost saving by eliminating preparation of seed bed and transplanting. But, it required increased input of fertilizers and pesticides because of the extended paddy period. Direct seeding in wet paddy (DSWP) gives faster growth and more uniform seedling emergence than direct-seeding in dry paddy. This research had an objective to develop an efficient N management practices for DSWP with split application of N fertilizer. A paddy field experiment was conducted to evaluate effects of starter N and N-topdressing which was delayed N application until 5-leaf stage, with comparison to transplanting (TP). Total amount of N application were two levels; 110kg and 77kg/ha. The N applications were split four times during rice growth stages; starter, topdressing at 5-leaf stage, top dressing at tillering stage, and topdressing at panicle initiation stage. DSWP had more tillers/$m^2$ than TP, but with the delayed heading. The DSWP plots which received N-topdressing at 5-leaf stage without starter N had higher leaf area index (LAI) and leaf greenness than the TP plot. Also, these DSWP plots had high leaf-N concentration at the heading stage, as calculated from leaf chlorophyll meter readings. Rice yield in DSWP with N-topdressing at 5-leaf stage was significantly higher than that in TP and in DSWP with starter N. Energy and N use efficiency were improved in DSWP with N-topdressing at 5-leaf stage. But, there were no significant differences in grain yield between the two levels of total amounts of N applications, 77kg and 110kg/ha. We concluded that starter N could not be used effectively by rice seedlings, but topdressing N at 5-leaf stage was an efficient N management for rice growth and yield in DSWP system.

• Journal of Ginseng Research
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• 제38권1호
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• pp.73-77
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• 2014

Field and nutrient cultures of American ginseng (Panax quinquefolius L.) were used to establish foliar symptoms related to boron (B) concentration in leaves and soils, and to evaluate radish as a time-saving model system for B nutrition. Application of excess B, 8 kg/ha versus the recommended 1.5 kg/ha, to field plantings of 2-, 3-, and 4-yr-old American ginseng plants just prior to crop emergence caused, within 4 wk after crop emergence, leaf symptoms of chlorosis followed by necrosis starting at the tips and progressing along the margins. The B concentration in leaves of 2-4-yr-old plants receiving 1.5 kg/ha Bwas $30{\mu}g/g$ dry mass compared to $460{\mu}g/g$ dry mass where 8 kg/ha B was applied. Similarly, B concentration in soils receiving the lower B concentration was 1.8 mg/g dry mass and $2.2-2.8{\mu}g/g$ dry mass where the higher B concentration was applied. Application of 8 kg/ha B reduced the dry yield of 3rd-yr roots by 20% from 2745 kg/ha to 2196 kg/ha and 4th-yr roots by 26% from 4130 kg/ha to 3071 kg/ha. Ginseng seedlings and radish were grown under greenhouse conditions in nutrient culture with four B concentrations ranging from 0 mg/L to 10 mg/L. At 5 mg/L and 10 mg/L ginseng and radish developed typical leaf B toxicity symptoms similar to those described above for field-grown plants. Increasing B in the nutrient solution from 0.5 mg/L to 10 mg/L decreased, in a linear fashion, the root and leaf dry mass of ginseng, but not radish. Given the many similarities of ginseng and radish to B utilization, radish might be used as a timesaving model system for the study of B, and other micronutrients, in the slow-growing perennial ginseng.

• 한국응용곤충학회지
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• 제31권2호
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• pp.174-181
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• 1992

씨고자리파리(Delia platura) 유충의 피해가 차후 대두 생육과 생산성에 미치는 영향을 기상생태형별로 조사하고 또 해충종합관리의 방안으로서 토양내 유기물함량, 토양의 종류, 피복등과 피해정도와의 관계를 분석한 결과를 종합해 보면 다음과 같다. 콩 초생단엽의 피해로 영양생장이 지연되었는데 일장에 의해 유도되는 개화기에는 큰 변화가 없었다. 인위적으로 적엽한 구 보다는 충접종에 의한 피해구에서 생육지연 현상이 두드러졌는데 이는 초생단엽 피해 외에 지하 경.근부가 함께 피해를 받은 때문이었다. 생산량은 초생단엽이 25% 피해를 받은 구부터 크게 감소하였다. 콩의 출현속도는 무피복구에 비해 피복구에서 빨랐는데 투명비닐의 촉진 효과가 가장컸다. 식양토와 식토구에서 재배한 콩의 피해가 적었으며 토양내 부엽토 함량이 증가하면 출현속도가 빨라져 초생단엽의 피해가 감소하는 것으로 나타났다.

• 한국작물학회지
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• 제26권1호
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• pp.115-120
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• 1981

토양수분이 인삼생육에 미치는 영향을 조사하기 위하여 토경Pot(1/2000cm)에 묘삼을 이식하여 토양수분함량별 지상부 및 지하부 생육장황, 근수량과 지상부 형질과의 상호관계를 조사하여 다음과 같은 결과를 얻었다. 1. 인삼생육에 대한 토양의 적정수분 함량은 포장용수량의 65. 5%(절대수분 22.1%였고 생육이 정지되는 토양수분 함량은 포장용수량의 31.5%(절대수분 10.7%)였다. 2. 토양수분 함중이 적은 곳에서는 출아 및 전엽율이 상당히 지연되었으며 엽면적외 감소와 지상부 결주가 많아져 근수량이 현저히 감소되였다. 3. 근수량은 엽면적(r=0.91**) 경직경(r=0.76**) 경장(r=0.71**) 지상부생중(r=0.96**)간에 각각 정의 상기관계가 있었고 지상부 결주율(r=-0.77**) 간에 부의 상관관계가 있었다. 4. 생근중과 수분함량(r=- 0.80**)간에 부의 상관관계가 있어 수분이 충분한 곳에서 자란 인삼은 조직이 치밀함을 나타내었다.

• 한국자원식물학회지
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• 제20권1호
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• pp.43-49
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• 2007

상사화류의 분류 및 품종 개발을 위해서 상사화속 22종류의 개화와 출엽 유형 및 특성을 조사하였다. 개화시기는 $7{\sim}8$월에 1종류, 8월에 12종류, 9월에 개화하는 것이 9종류였다. 꽃의 모양은 L. radiata 형이 9종류, L. squamigera 형이 7종류, 중간형이 7종류이었다. 꽃의 색깔은 적색계열과 분홍색 계열이 각각 3종류, 백색계열이 7종류, 황색 계열이 4종류, 주황색계열이 3종류, 자색 계열이 2종류였다. 임성은 좋은 것이 10종류, 조금 되는 것이 2종류였었다. 화분립(pollen grain)의 평균 길이는 $48.53{\sim}88.62{\mu}m$ 였으며, 평균 폭은 $22.87{\sim}33.67{\mu}m$였다. 출엽형은 춘기출엽형이 11종류, 추기출엽형이 10종류였다. 잎의 Hunter value은 $L^*$값이 $31.6{\sim}45.2,\;a^*$값은 $-6.74{\sim}-17.46,\;b^*$값은 $6.19{\sim}21.89$의 범위에 있었다. 잎폭은 $0.90{\sim}2.35cm$였으며, 모양은 대부분 장방형이었다. 표피세포 길이는 $0.33{\sim}0.75mm$였으며, 폭은 $38.53{\sim}90.00{\mu}m$였다. 기공은 대부분 뒷면에 많이 분포되어 있었다. 기공의 길이는 $67.12{\sim}104.89{\mu}m$였으며, 폭은 $14.90{\sim}71.52{\mu}m$였다.

• 한국작물학회지
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• 제48권6호
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• pp.460-464
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• 2003

본 연구는 벼 종자의 파종 후 발아, 유묘출현 및 생육 초기에 가하여지는 광질처리가 유묘 출현, 생장, 형태, 엽록소 함량 및 광합성율에 미치는 영향을 조사하여 벼의 육묘에 이용되고 있는 부직포의 색상을 전환할 필요가 있는가를 검토하고자 실시하였으며 그 결과를 요약하면 다음과 같다. 1. 파종 직후에 가하여지는 광질처리에서 유묘출현율은 조사일 모두 일미벼에서는 광질처리간 차이가 없었다. 그러나 동진벼와 대산벼에서는 원적색광 처리에서 가장 낮았으며, 청색광과 적색광간에는 차이가 거의 없었다. 2. 파종 직후에 가하여지는 광질처리로 인하여 원적색광 처리에서 초장과 엽장이 가장 짧았던 반면, 적색광은 뿌리수를 증대시켰다. 3. 파종 직후에 가하여지는 광질처리로부터 지상부 건물중은 청색광 처리에서, 뿌리의 건물중은 적색광 처리에서 가장 많았던 반면, 지상부 및 뿌리 건물중 모두 원적색광에서 가장 적었다. 4. 엽록소 함량과 광합성율 모두 품종간에는 일정한 경향이 없었으나, 광질처리에서는 이들 모두 적색광에서 가장 높고, 청색광, 원적색광 순으로 감소하였다.

• 한국초지조사료학회지
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• 제13권2호
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• pp.132-138
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• 1993

Yield and plant constituent responses of forage sorghum cultivars have usually been compared in uniform defoliation management test. However the influence of harvest time on differential response of cultivars needs more precise definition. Therefore this study with sorghum-sorgo-sudan hybrid cv. NC+Sweet Leaf, and Super Su 22 and Sorghum-Sorghum hybrid cv. Pioneer 931 was carried out under two defoliation regimes, namely defoliation at heading stage of each variety and defoliation on the same calendar date in response to heading stage of early variety. The results are summarized as follows; 1. Three harvests were taken by early variety with 80 days and two harvests by late variety with 94 days from sowing to heading. 2. Dry matter and TDN yield tend to be higher when the plants are cut at ear emergence stage of late variety. 3. Crude protein content was similar for the same growth growth stage of 1st growth and 1st regrowth, and rather big different between varieties. 4. Considering only dry matter and TDN yield, it is recommendable to cut two times at ear emergence stage of late variety and also three times at ear emergence stage of early variety in view point of utilization period extension and distribution of forage products.

• 한국환경과학회지
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• 제33권5호
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.

• 한국초지조사료학회지
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• 제7권3호
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• pp.146-152
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• 1987

Sorghum cv. Pioneer 93 1, sorghum-sudangrass hybrid cv. Sioux and maize plant cv. Blizzard were assayed for toxic concentrations of nitrate-nitrogen ($NO_3$-N) and their relationship to morphological characteristics and environmental temperature in a field and phytotron trial. In the phytotron, sorghum and maize plants ranging from emergence to heading stage, were grown under different day/night temperatures of 30125, 25/20,28/18 and 1818 degree C. Nitrate-nitrogen in sorghum and maize plants was accumulated mainly in stems. Therefore nitrate concentration in the young plants was increased as development of stalks advanced and was highest at the stage of 3-4 leaves, when the plants had a leaf weight ratio 0.78-0.80 g/g plant weight. However, nitrate concentrations of the plant decreased as morphological development progressed, especially from the stage of growing point differentiation. Correlation coefficients showed a positive correlation of nitrate concentration with leaf weight ratio, leaf area ratio and specific leaf area, while plant height, dry matter percentage and absolute growth rate showed a negative association with TEX>$NO_3$-N ($P{\le}0.1$%). Cyanogenic glycosides, total nitrogen and crude protein were close associated with nitrate accumulation, and positively significant ($P{\le}0.1$%). High temperature over 30/25^{\circ}C.$ for 3 weeks increased N-uptake and dry matter accumulation, but reduced nitrate concentration. Under cold temperature below 18/8^{\circ}C.$ concentration of nitrate-N was increased in spite of its limited nitrogen uptake and plant growth.