Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of ‘Bonus’ tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in NO3-N, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato.

수경재배 시스템에 있어서 배액의 재활용은 생산비 절감 및 환경오염 방지를 위하여 중요하다. 방울토마토를 반촉성 수경재배 하면서 생육 단계별 공급액, 배액 및 잎의 무기성분 분석을 통하여 순환식 수경재배 시스템 개발을 위한 기초자료를 확보하고자 본 연구를 수행하였다. 연구목적을 달성하기 위해 주기적으로 공급액, 배액 및 식물체 잎을 채취한 후 무기물 함량을 분석하였다. 생육 초기에는 배액의 EC가 공급액과 비슷한 약 2.0dS·m-1였지만, 생육 후기로 갈수록 높아져 9화방 착과기에는 4.5dS·m-1였다. 영양생장이 왕성한 생육 초기의 pH는 6.4~6.7 범위였으나 생식생장이 강해진 생육 후기에는 5.9~6.1로 낮아지는 경향이었다. 생육 초기에는 공 급액과 배액의 NO3-N, P, K, Ca 및 Mg 농도가 비슷하였지만 생육 후기로 갈수록 공급액보다 배액의 농도가 높아지는 경향이었다. 생육 초기에 잎의 T-N 함량이 높았지만 후기로 갈수록 낮아지는 경향이었다. K와 Ca 함량은 생육 초기에는 낮았으나 후기로 갈수록 높았으며, P와 Mg 함량은 생육초기부터 후기까지 유사한 수준으로 분석되었다. 이상의 결과는 토마토 수경재배를 배액재 활용에 있어 무기원소 농도 변화를 교정하기 위한 기초 자료로 활용될 수 있을 것이다.

This study investigated the Texture Profile Analysis and Sensory characteristics analysis of 6 different Pork Meat-substituted Soybean Curd (PMSC) products with different gluten-fiber (GF) contentst. PMSC types were PMSC-GF 5%, PMSC-GF 10%, PMSC-GF 15%, PMSC-GF 20%, PMSC-GF 25%, and PMSC-GF 30%. The lightness (ΔL value) of cooked PMSC was decreased, whereas the redness (Δa value) and yellowness (Δb value) of cooked PMSC was not changed. Texturometer (TA XT Plus, England) was used for objective test and hardness, springiness, cohesiveness and chewiness of sensory characteristics were measured. PMSC with GF 5% to 15% were characterized high hardness score but PMSC with GF 20% to 30% were not significantly different. PMSC-GF 30% was the highest score in springiness and PMSC-GF 5% was the lowest. PMSC-GF 25% and 30% were high cohesiveness score but was not significantly different (p<0.05). Fourteen sensory descriptors were developed to evaluate the sensory characteristics of PMSC. The sensory characteristics of PMSC were sweetness, saltiness, springiness, hardness, chewiness, meat flavor, odor, loose particle and so on. Six different PMSC showed no significant difference in the attributes of loose particle. But PMSC-GF 5% and PMSC-GF 10% showed significant difference in the attributes of hardness. PMSC-GF 25% and PMSC-GF 30% showed no significant difference in the attributes of hardness. PMSC-GF 30% was the highest springiness score and PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in the attributes of springiness. Overall consumer acceptance was surveyed. PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in the attributes of color. PMSC-GF 25% and PMSC-GF 30% was the highest in the attributes of springiness and high moistureness, taste acceptance and overall acceptance. PMSC-GF 5%, PMSC-GF 10% and PMSC-GF 15% showed no significant difference in overall consumer preference but PMSC-GF 25% and PMSCGF 30% showed significant difference. Consequently it is indicated that texture of cooked PMSC-GF 25% and PMSC-GF 30% is very important sensory characteristics.

Skin-derived precursor cells (SKPs) are multipotent, sphere-forming and embryonic neural crest‐related precu- rsor cells that can be isolated from dermis. It is known that the properties of porcine SKPs can be enhanced by leuke- mia inhibitory factor (LIF) which is an essential factor for the generation of embryonic stem cells in mice. In our pre- sent study, to enhance or maintain the properties of murine SKPs, LIF was added to the culture medium. SKPs were treated with 1,000 IU LIF for 72 hours after passage 3. Quantitative real time RT‐PCR was then performed to quantify the expression of the pluripotent stem cell specific genes Oct4, Nanog, Klf4 and c‐Myc, and the neural crest specific genes Snai2 and Ngfr. The results show that the expression of Oct4 is increased in murine SKPs by LIF treatment whereas the level of Ngfr is decreased under these conditions. Interestingly, LIF treatment reduced Nanog exp- ression which is also important for cell proliferation in adult stem cells and for osteogenic induction in mesenchymal stem cells. These findings implicate LIF in the maintenance of stem- ness in SKPs through the suppression of lineage differen- tiation and in part through the control of cell proliferation.

Cells that have endogenous multipotent properties can be used as a starting source for the generation of induced pluripotent cells (iPSC). In addition, small molecules associated with epigenetic reprogramming are also widely used to enhance the multi- or pluripotency of such cells. Skinderived precursor cells (SKPs) are multipotent, sphereforming and embryonic neural crest-related precursor cells. These cells can be isolated from a juvenile or adult mammalian dermis. SKPs are also an efficient starting cell source for reprogramming and the generation of iPSCs because of the high expression levels of Sox2 and Klf4 in these cells as well as their endogenous multipotency. In this study, valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, was tested in the generation of iPSCs as a potential enhancer of the reprogramming potential of SKPs. SKPs were isolated from the back skins of 5-6 week old C57BL/6 X DBA/2 F1 mice. After passage 3, the SKPs was treated with 2 mM of VPA and the quantitative real time RT-PCR was performed to quantify the expression of Oct4 and Klf4 (pluripotency specific genes), and Snai2 and Ngfr (neural crest specific genes). The results show that Oct4 and Klf4 expression was decreased by VPA treatment. However, there were no significant changes in neural crest specific gene expression following VPA treatment. Hence, although VPA is one of the most potent of the HDAC inhibitors, it does not enhance the reprogramming of multipotent skin precursor cells in mice.

Human fibroblasts that maintain the structural integrity of connective tissues by secreting precursors of the extracellular matrix are typically cultured with serum. However, there are potential disadvantages of the use of serum including unnatural interactions between the cells and the potential for exposure to animal pathogens. To prevent the possible influence of serum on fibroblast cultures, we devised a serum-free growth method and present in vitro data that demonstrate its suitability for growing porcine fetal fibroblasts. These cells were grown under four different culture conditions: no serum (negative control), 10% fetal bovine serum (FBS, positive control), 10% knockout serum replacement (KSR) and 20% KSR in the medium. The proliferation rates and viabilities of the cells were investigated by counting the number of cells and trypan blue staining, respectively. The 10% FBS group showed the largest increase in the total number of cells (1.09 × 105 eell₃/ml). In terms of the rate of viable cells, the results from the KSR supplementation groups (20% KSR:64.7%; 10% KSR: 80.6%) were similar to those from the 10% FBS group (68.5%). Moreover, supplementation with either 10% (30 × 104 eell₃/ml) or 20% KSR (4.8 × 104 cells/ml) produced similar cell growth rates. In conclusion, although KSR supplementation produces a lower cell proliferation rate than FBS, this growth condition is more effective for obtaining an appropriate number of viable porcine fetal fibroblasts in culture. Using KSR in fibroblast culture medium is thus a viable alternative to FBS.

Somatic cells nuclear transfer (SCNT) is a useful tool in studies of developmental biology and animal cloning. However, SCNT experiments only are allowed to skilled technical experts. In this experiment, laser-assisted zona pellucida piercing tool (LASER) was applied in murine SCNT. LASER minimized the use of piezo-driven micromanipulator (PIEZO), reducing chances of problems caused by PIEZO pulses. LASER reduced time that took to pierce zona pellucida in removal of nucleus from oocyte and somatic cell injection, which might have taken longer time with PIEZO. Time and difficulties that took researcher of equivalent skilled for their experiments were decreased with LASER, and this might affect the improvement of embryonic development. (LASER, 6.2% versus PIEZO, 2.9%; P<0.05). Thus, these data support that the use of LASER can be used for zona pellucida piercing in murine SCNT program as an alternative to PIEZO.

국화 6 품종을 대상으로 감마선(35 Gy) 조사에 의해 유기 된 화색변이체를 선발하고, 식물체 재생을 위한 배지내 식물생 장조절제 적정농도를 구명하여 신품종 육성 가능성을 검토하고 자 수행하였다. 고유품종과 다른 꽃잎의 화색변이율은 ‘SP-410’ 이 15.7%로 가장 높았으며, ‘예스스타’가 10.6%, ‘무지개’가 10.3%순 이었다. ‘무지개’는 이중색(황색/적색, Y7D/R40A) 에서 적색(R42B)으로, ‘예스라인’은 자주색(RP74C)에서 진자 주색(RP63B)으로, ‘예스스타’는 황색/적색(Y4A/RP59A) 이 중색에서 적자주색(RP64A)으로, ‘SP-410’은 백색(W155C)에서 황색(Y2C)으로, ‘예스투게더’의 화심색은 백색(W155C)에서 연보라색(P76B)로, ‘예스우리’의 화심색은 연녹색(YG149A)에 서 짙은 녹색(GY1C)으로 화색이 변한 변이체를 선발하였다. 화색변이체 꽃잎의 신초형성을 위한 배지내 식물생장조정제 의 최적조합은 BA 1.0 mg/L와 NAA 0.5 mg/L, BA 2.0 mg/L 와 NAA 0.5 mg/L의 2조합이였으며, 신초형성율은 품종간에 차이가 있어 ‘예스라인’이 91.6%로 가장 높았다. 감마선 조 사에 의한 화색 변이체의 꽃잎배양 유래 재생식물체는 영양 번식으로 유지되었으며, 3년동안 재배한 결과 화색과 꽃잎의 형태적 특성 차이가 없었다.