• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2018.10a
• /
• pp.49-49
• /
• 2018

본 연구는 관상가치가 높아 조경 및 관상소재로 개발이 가능한 큰개관중의 전엽체 증식 및 포자체 형성에 적합한 배양조건을 구명하고자 수행되었다. 실험재료는 무가온 온실에서 채집한 포자를 기내에서 발아시켜 전엽체를 획득한 후 8주 간격으로 계대배양하여 실험에 사용하였다. 배지종류에 따른 전엽체의 기내 증식 및 형태형성의 영향을 알아보고자 배양된 전엽체 300mg을 메스로 다진 다음 농도를 1/4, 1/2, 1, 2배로 조절한 MS와 Knop배지에 8주간 배양하였다. 그 결과, 1MS배지에서 전엽체의 생체중이 5.5g으로 가장 많이 증가하였다. 1MS를 제외한 타 처리구는 생체중의 증가수준이 1.1-3.0g에 머물러 1MS배지보다 저조한 수준을 보였다. 현미경을 이용한 전엽체의 관찰결과, 1MS배지는 엽육의 색이 녹색으로 생육이 양호하였다. 전엽체의 증식이 가장 저조하였던, 2MS와 1/4MS는 생육의 저조뿐만 아니라 노화현상도 관찰되었다. 포자체 형성을 위한 최적의 토양조건을 알아보고자, 원예상토, 피트모스, 펄라이트 및 마사토의 비율을 5종류로 달리하여 배양토를 혼합하였다. 혼합된 토양은 사각분($7.5{\times}7.5{\times}7.5cm$)에 충진하여 기내배양된 전엽체 1g을 증류수와 함께 10초간 분쇄한 다음 토양표면에 분주 후 10주간 재배하였다. 그 결과, 원예상토가 높은 비율로 첨가된 혼합조건에서 포자체의 형성이 우수하였다. 그중 원예상토와 마사토를 2:1(v:v)로 혼합한 토양, 원예상토와 펄라이트를 2:1(v:v)로 혼합한 토양에서 포트 당 각 357.0, 339.8개의 포자체가 형성되었다. 또한 형성된 포자체의 생육을 조사한 결과 원예상토와 마사토를 2:1(v:v)로 혼합한 토양에서 생체중, 엽수, 엽장, 엽폭, 근수, 근장 및 SPAD value 등의 생육수치가 우수하였다. 따라서 큰개관중의 전엽체 증식에 적합한 배지는 1MS로 판단되었으며, 포자체 대량생산을 위해서는 원예상토와 마사토를 2:1(v:v)로 혼합한 토양이 적합하다고 판단된다.

• Weed & Turfgrass Science
• /
• v.4 no.2
• /
• pp.144-150
• /
• 2015

Silicate fertilizers known to be effective in improving the growth and density of zoysiagrass. Most silicate fertilizers being used in Korea are slag-originated silicate fertilizer, but some water soluble silicate fertilizers are commercially available recently. This study was conducted to know the effect of water soluble silicate fertilizer, on the growth of zoysiagrass and the change of soil chemical properties in Wagner pot and field experiment. Root length, fresh and dry weight of shoots and stolons, the number of shoots and stolons, total of stolons length and the $SiO_2$ content of internal plant were significantly increased by the $SiO_2$ content but chemical properties of the soil were not significantly changed by the $SiO_2$ content. The $SiO_2$ contents of 18 and $36{\mu}lml^{-1}$ did not show significance difference, and therefore a reasonable application the content of $SiO_2$ was thought to be $18{\mu}lml^{-1}$. Foliar spray of water soluble silicate fertilizer is believed to enhance the growth and density of zoysiagrass than soil application.

• Journal of Korean Society of Forest Science
• /
• v.88 no.2
• /
• pp.249-254
• /
• 1999

The effects of various levels of Al concentration on growth, nutrient status and net photosynthetic rate of 2-year-old Pinus densiflora Sieb. et Zucc. seedlings grown in a nutrient culture solution were investigated. Al concentrations were added as aluminum chloride($AlCl_3$) at 0(control), 10, 30 and 60ppm to the nutrient culture solution. The nutrient culture solution was maintained at pH 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution and grown in a greenhouse for 90 days from May 8 to August 6, 1996. The treatment above 10ppm of Al concentrations induced a significant reduction on the dry weight growth of the seedlings. The relative growth rate(RGR), net assimilation rate(NAR) and net photosynthetic rate of the seedlings were reduced with increasing of Al concentrations in the nutrient culture solutions. This result suggests that reductions in the RGR and NAR of the seedlings were mainly due to the inhibition of net photosynthesis. In addition, the increase of Al concentrations in a nutrient culture solution decreased the concentration of essential mineral elements such as Ca and Mg in the needle of the seedlings. However, the concentrations of Al of each plant organ increased in the treatment above 10ppm of Al concentrations in the nutrient culture solutions. This result suggests that the increased Al concentration in the belowground part resulted from the decreased concentration of essential mineral elements in the aboveground part of the seedlings.

• Journal of Bio-Environment Control
• /
• v.10 no.4
• /
• pp.207-212
• /
• 2001

The environmental characteristics, absorption rate of NO$_2$, physiological response, and quality of lettuces were examined in a semi-closed plant production system consisted of human and plant modules. Leaf lettuces were transplanted to 10-cm diameter pots at 4-to 5-leaf stage, and grown in a gas-fumigated plant module. Air containing NO$_2$was circulated 10 min-ON/ 20 min-OFF between the human and plant modules by a diaphragm. At 0.13, 0.30, and 0.45 $\mu$mol.mol$^{-1}$ NO$_2$, NO$_2$ decrements in the chamber during the 10 min were 0.040, 0.109, and 0.149 $\mu$mol.mol$^{-1}$ , respectively. The NO$_2$absorption rate of the plants was estimated to be 0.078 $\mu$mol.mol$^{-1}$ .m$^{-2}$ .min$^{-1}$ at 0.45 $\mu$mol.mol$^{-1}$ NO$_2$ was less than that of the control plant at 4th and 5th days, whereas the respiration rate was the same. The lettuce grown at 0.45 $\mu$mol.mol$^{-1}$ NO$_2$ had similar leaf length, leaf area, dry and fresh weights, and quality to that grown without NO$_2$.

• Research in Plant Disease
• /
• v.15 no.3
• /
• pp.198-201
• /
• 2009

Bacterial wilts, caused by Ralstonia solanacearum, is a very destructive disease to tomato plants (Solanum lycopersicum) in Korea. Selection of resistant cultivar is the best way to prevent or reduce the occurrence of this disease. Thirty-nine tomato cultivars, twenty-one cherry tomato cultivars and thirteen rootstock tomato cultivars were inoculated with Ralstonia solanacearum, to evaluate tomato cultivars for resistance against bacterial wilts. Thirty-seven cultivars were highly susceptible to bacterial wilts and 61-100% of their whole tissue became wilted within 10 days after inoculation. Twenty-four cultivars showed moderate resistance and twelve were resistant to bacterial wilts. In an evaluation of 73 major commercial cultivars, 'Lilyance', 'TP-7', 'Choice', 'Dadaki', 'Akiko', 'Redstar', 'Match', 'B-blocking', 'Magnet', 'Support', 'Friend' and 'Special' were found to have a high level of resistance to bacterial wilts of tomatoes.

• Research in Plant Disease
• /
• v.19 no.1
• /
• pp.55-59
• /
• 2013

The purpose of this experiment was to investigate the development of new spot disease on the leaf and stem of rosemary (Rosmarinus officinalis) in commercial greenhouses at Jeonju and Namwon in Korea. Incidence of target spot on rosemary was higher at the end of the rainy season with high humidity. Those symptoms were black ring spots (3-5 mm in diameter) and withering on green leaves and stems. Conidiophores and conidia were formed on the infected tissue in moist chamber and conidia were shown as the cylindrical and oval types in chain, ranged from 55 to $275{\mu}m$ in length, and 7 to $14{\mu}m$ in width. Conidia with eight to ten pseudosepta were formed on the conidiapore. The optimum growth temperature of isolates was $30^{\circ}C$ on the PDA medium under the dark condition. In the pathogenesis test, the target spot and withering symptoms were appeared on the leaves and stems 3 days after inoculation showing similar symptoms compared to those of in nature. The same fungus was re-isolated from infected lesion, indicating that Corynespora cassiicola caused leaf target spot and twig blight on rosemary. The rDNA ITS nucleotide sequences of the pure cultured isolate from the diseased area on rosemary showed 100% similarity to the sequences of C. cassiicola available in the GenBank database (JQ595296, JQ595297, FJ852715 and AY238606). Therefore, we report that the target spot of leaves and stems in rosemary was caused by C. cassiicola.

• The Korean Journal of Mycology
• /
• v.40 no.4
• /
• pp.271-276
• /
• 2012

A mycoparasite, Paraconiothyrium minitans CM2 was selected for biological control of sclerotinia rot of lettuce caused by Sclerotinia sclerotiorum. The experiment was carried out in a lettuce greenhouse in Yangpyeong from March to April.. When lettuce sclerotinia rot showed in the early stage of occurrence, Conidial suspension of the mycoparasite was weekly treated once to three times onto soil surface around lettuce plants. Incidence of sclerotinia rot in the once-application plot of the mycoparasite ($1{\times}10^7$ spores/$m{\ell}$) and in the benomyl(WP)-treated plot was 11.0% and 2.7%, respectively, whereas that of control was 31.0%. Incidence of twice- and three-application plots of the isolate was 7.9% and 12.8%, respectively. For increasing the effect of the mycoparasite, the experiment for the timing of application of P. minitans CM2 was carried out in a lettuce greenhouse in Yangpyeong and Suwon. Control efficacy against lettuce sclerotinia rot in the soil-drenching plots of P. minitans CM2 ($5{\times}10^6$ spores/$m{\ell}$) in the planting was 75.3~84.7%, and control effect by treatment of the isolate at the pot drenching+the soil-drenching plots in the early stage of disease occurrence was 63.8~58.0%. As the results, P. minitans CM2 could be a prospective biofungicide for biological control of sclerotinia rot of lettuce.

• Research in Plant Disease
• /
• v.11 no.2
• /
• pp.152-157
• /
• 2005

In a course of searching for biofungicide to control crisphead lettuce bottom rot caused by Rhizoctonia solani, we have isolated an antagonistic bacterium from lettuce rhisophere soil. A total of 702 bacterial isolates were isolated and tested for in vitro growth inhibition of R. solani. Seven strains appeared to have strong antagonistic effect against R. solani in in vitro growth inhibition assay. In the pot experiments, a strain BW-13 showed the most potent disease control effect on the both lettuce seedlings and adults plants. Therefore, the BW-13 was selected as a biocotrol candidate against crisphead lettuce bottom rot. Based on its morphology, physiological characteristics, and 165 rRNA gene analysis, the BW-13 was finally identified as Stenotrophomonas maltophilia. This study indicated that S. maltophilia BW-13 could be used as a biocontrol agent to control crisphead lettuce bottom rot.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.5
• /
• pp.503-514
• /
• 1997

The morphogenesis of panicle and spikelet in paddy rice has been studied in high yielding Indica$\times$Japonica hybrid cultivar, Milyang 23 and a Japonica type cultivar, Koshihikari. Germinated seeds planted in $5000^{-1}$ a pots filled with submerged soil and cultured under natural conditions. The young panicle of main stem were continuously dissected and observered by Cryo-SEM from the panicle initiation stage until heading stage. Although the date of panicle differentiation and heading in Koshihikari earlier than those of Milyang 23. the sequence of panicle development in two cultivars begins when first bract primordium at opposite side of flag-leaf primordium differentiated, synchronously followed by growth of the primary branch primordia (PBPs) and secondary branch primordia (SBPs), spikelet primordia(SPs), glumes as lateral organs on rachilla and organs composing single floret, and successive sporogenesis in the young spikelets continue after the enclosure by lemma and palea. The PBPs are acropetally initiated from the base of the panicle primordium, and the SBPs alternately differentiate from the base of upper PBP which differentiate later than the lower PBP. Spikelet development starts at the top of upper side PBP of the young panicle and continue basipetally even though SBPs continue to develop at the lower primary branch. Each PBP, SBP and SP differentiate with differentiation bract or bract hair cell around the base of each their primordia. The observation could confirm that Milyang 23 has not only 2~3 more defferentiated PBPs, but also more SBPs and SPs especially from middle-lower primary branch, at end of their differentiation stages, as compared to those of Koshihikari.

• Korean Journal of Agricultural Science
• /
• v.37 no.2
• /
• pp.199-207
• /
• 2010

This research was conducted to determine the influence of physiological and chemical properties of root substrates on the growth of the daughter plants of 'Maehyang' strawberry produced by bag culture. The daughter plants produced by stock plants during bag culture were individually separated and grown in 10-cm diameter plastic pots containing six different formulations of root substrates: a) 50% peatmoss plus 50% vermiculite (5:5 by volume, A), b) 70% peatmoss plus 30% perlite (7:3, B), c) 70% coir dust plus 30% perlite (7:3, C), d) mixture of 35% coir dust, 35% peatmoss, and 30% perlite (3.5:3.5:3.0, D), e) mixture of 20% rice hull, 70% coir dust, and 10% perlite (2:7:1, E), and f) 30% rice hull plus 70% coir dust (30:70, F). The container capacity and air filled porosity of the growing medium varied greatly among the six substrate formulations evaluated. The substrates E and F had less container capacity and higher air-holding spaces than the rest of the formulations. Therefore, these two formulations (E and F) may cause a problem in water management during the production of healthy daughter plants. The substrate formulations A, B, and D retained higher nitrogen (N) concentrations than other formulations containing coir dust or rice hull. The substrate formulations E and F which contained rice hull had lower N, phosphorus (P), and potassium(K) concentrations than other substrate formulations containing coir. The quality of the daughter plants grown in all six different substrate formulations was good with the crown diameters at around 10 mm. Fresh weights of the daughter plants grown in substrate formulations A, C, and D were higher than those obtained from B, E, and F. Dry weights of the daughter plants showed a similar trend. The daughter plants having high fresh and dry weights and increased crown diameter are in demand by the industry. For this reason, the substrate formulations A, C and D can readily be used as potting mixes during the production of 'Maehyang' strawberry transplants utilizing the bag culture system.