• FLOWER RESEARCH JOURNAL
• /
• v.18 no.4
• /
• pp.266-270
• /
• 2010

Corylopsis coreana is an endangered Korean native plants. This is one of the genus that have high ornamental value for flowering plants available for garden shrub, bonsai, and pot plants. In this study, the methods to encourage seed germination rate were investigated for its ornamental uses. The germination rate of Corylopsis coreana seeds stored under dry-cold condition was very low, 12%, 12%, 8%, and 10%after 40, 70, 85, and 100 days storage respectively. But the germination rate of Corylopsis coreana seeds stored under wet-cold condition was higher than these, 20%, 54%, 78%, and 96% after 40, 70, 85, and 100 days storage respectively. Dry seeds sowed directly without $GA_3$ treatment showed no germination regardless of storage type(cold or room temp.) or storage periods. On the other hand, the soaking treatment with $GA_3$ 50~500 ppm for 24 hours was very effective to increase the germination rate. The most effective $GA_3$ levels was different by storage type(cold or room temp.) and storage periods. But the effect of $GA_3$ was decreased by prolonging of the storage period. Soaking treatment with $Ca(NO_3)_2$ 5, 10, 20 mM, $KNO_3$ 5, 10, 20 mM for 24 hours showed no effect.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.59 no.4
• /
• pp.457-462
• /
• 2014

This study was conducted to evaluate basic seed characteristics such as morphological characteristics and various seed vigor using 4 sorghum varieties, Nampungchal, Donganme, Hwanggeumchal and Whinchal. No difference was shown in morphological characteristics of the varieties except that the width. Whinchal has bulb-shaped seed, while the other varieties have oval-shaped seeds. The seed coat color of Whinchal is obviously different from those of the other varieties; especially, Nampungchal and Hwanggeumchal are not glossy. Germination rate were Hwanggeumchal > Nampungchal > Donganme > Whinchal in the order of higher rate in standard germination tests and cold germination test. In the ageing test, Donganme showed the lowest 15% decrease in comparison with the standard cultivar. Electric conductivity (EC) has negative correlation with standard germination tests, cold germination test and accelerated ageing test. In the percentage of emergence (PE), Hwanggeumchal was the highest 85.7% which was more than 40% to the lowest Whinchal. Mean emergence time (MET) showed significant difference between the varieties; Whinchal showed the slowest 6.0 days.

• Journal of Forest and Environmental Science
• /
• v.29 no.2
• /
• pp.165-172
• /
• 2013

The habitats characteristics of Rhododendron micranthum Turcz. were investigated to compile basic data for conservation and restoration. Natural habitats were located at altitudes of 100-500 m with inclinations of $10-35^{\circ}$. Rhododendron micranthum population was classified into Pinus densiflora dominant population. In the study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, exchangeable sodium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 4.10-8.64%, 0.18-0.46%, 8.69-26.70 $mgkg^{-1}$, 0.10-0.23 $cmol^+kg^{-1}$, 0.06-0.10 $cmol^+kg^{-1}$, 0.85-4.10 $cmol^+kg^{-1}$, 0.24-0.64 $cmol^+kg^{-1}$, 12.76-20.90 $cmol^+kg^{-1}$, 4.34-5.15. Rooting rate is too low, cutting propagation, breeding methods are not good. Also, this study was investigated seed germination of R. micranthum depends on soaking treatment. R. micranthum was soaked with tap water for four days, the average values of germination day were represented of 70%/1 week.

• Journal of Environmental Science International
• /
• v.28 no.11
• /
• pp.907-915
• /
• 2019

This study aims to identify the most tolerant species under salinity stress from amongst Asteraceae and Poaceae. The seeds of six species were exposed to different concentrations of $CaCl_2$ (0, 9, 18, 45, 90 mM) and NaCl (0, 17, 34, 85, 170 mM), and germination was measured once every two days. The results indicated that percent germination of the six species of Asteraceae and Poaceae seeds were affected differently by changes in salinity concentration. Seed germination was reduced as salinity levels increase, and longer mean germination times correlated to lower percent germination and earlier germination cessation. Both Asteraceae and Poaceae seeds had the highest germination rates at 18 mM $CaCl_2$ and 34 mM NaCl, and seed germination and growth were severely reduced at salinities greater than 90 mM $CaCl_2$ and 170 mM NaCl. In the seeds of Poaceae, salt resistance was strong in the order of Miscanthus sinensis Andersson, Pennisetum alopecuroides (L.) Spreng., and Phragmites communis Trin. In the seeds of Asteraceae, salt resistance was strong in the order of Dendranthema zawadskii var. latilobum (Maxim.) Kitam, Aster yomena (Kitam.) Honda, and Dendranthema boreale (Makino) Ling ex Kitam.. Overall, the germination rate was higher in Asteraceae than in Poaceae. This study demonstrated that Dendranthema zawadskii var. latilobum (Maxim.) Kitam. is the most tolerant species and that a relationship exists between the salt tolerance of percent germination and the mean germination time in the leaves.

• Journal of Practical Agriculture & Fisheries Research
• /
• v.20 no.2
• /
• pp.89-97
• /
• 2018

This study was conducted to elucidate the effect of after-ripening of gourd fruits before seed collection. Five varieties of commercial gourd varieties were cultivated and the fruits were picked after 24, 31, 50, and 70 days from pollination. For after-ripening treatments the fruits were placed for five days in a cool, air-circulated place while a number of fruits were placed for longer periods to 85 days including growing period, 24 + 62 days, 31 + 55 days, 50 + 35 days, and 70 + 15 days. The seeds collected from fruits harvested on 24^th day were not emerged at all, but the seeds from after-ripening treatment for 62 days showed 78% emergence or higher. The growth of seedlings showed the effects of after-ripening treatment of the fruits before seed collection; the seeds collected after ripening treatment showed better hypocotyl growth and larger embryo size than the non-treated seeds.

• Research in Plant Disease
• /
• v.15 no.3
• /
• pp.187-192
• /
• 2009

Pepper powdery mildew, Leveillula taurica is one of the most important pathogens of pepper in the greenhouses and fields in Korea and is becoming a worldwide disease. These experiments were carried out to investigate the optimal germination, disease development conditions, disease incidence and effective inoculation methods of pepper powdery mildew. The incidence of powdery mildew was investigated throughout the country based on the major pepper growing areas in 2009. The average rate of infected leaves ranged from 15.3% to 81.8% in greenhouses and fields. Powdery mildew incidences were more severe in greenhouses than those of fields. The optimal temperature for conidial germination was $25^{\circ}C$ and showed the highest germination at 6 hs after treatment. The range of temperature for germination was $10^{\circ}C$ to $35^{\circ}C$. Temperature of greater than $30^{\circ}C$ and below $20^{\circ}C$ affected the abnormal germination and germ tube elongation. The optimal relative humidity for germination and germ tube elongation was 85% and germination increased as relative humidity increased. Disease development started 8 days after inoculation and showed the highest disease severity at 15 days in greenhouse and field regardless of varieties. Among three different inoculation methods tested the spore dropping method was better than touching with infected leaves and spraying with spore suspension. However, the method has limitation in mass inoculation due to the amount of time consumed.

• ALGAE
• /
• v.38 no.2
• /
• pp.151-157
• /
• 2023

Grateloupia turuturu is a red alga with a flat but firm slippery thallus. Throughout its lifetime, this alga experiences a wide range of environmental stresses in the intertidal rocky shores. The aim of this study is to investigate the effect of salinity and irradiance on the early developmental stages of G. turuturu tetrasporophytes. The released carpospores were cultivated at different salinities (S = 15, 25, and 35) and irradiances (50, 100, and 200 μmol photons m^-2 s^-1). Germination of carpospores and development of juvenile tetrasporophytes were observed every 5 days and recorded by a digital camera. Discoid crusts were formed at all conditions within 5 days. The discoid crusts at 200 μmol photons m^-2 s^-1 died within 20 days regardless the salinity. The discoid crusts at S = 35 also died at all irradiance conditions within 25 days. Except for those at S = 35 and 200 μmol photons m^-2 s^-1, the discoid crusts reached about 8,000-9,000 ㎛² by day 20. Regardless of irradiance, the upright thalli formation rate from discoid crusts was 85 and 10% at S = 15 and S = 25, respectively. These results suggest that salinity and irradiance are important factors influencing early developmental stages of G. turuturu.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.5 no.4
• /
• pp.1-9
• /
• 2002

This study is carried out to make the environmentally affinitive porous planting block for revegetation and to make a effective program for greening plans. The summary is shown below. 1. In order to get stronger intensity and distribute proper porosity in the block for planting, the cements mixed with fine soil were used and the finer in soil grains gives the stronger in intensity of the cements. Use of the furnace slag cements instead of the portland cements showed relatively stronger in intensity of the block. The intensity of the block became stronger when the mixed ratio of the cements to soil is 5 : 1, but the pore space ratio was lower. The percolate pH of the portland cements after one month of treatment was 13.1 but the percolate pH of the furnace slag cements was shown lower. To mold proper porous planting blocks, the proper combination of additives such as the dehydrating agent, elastic agent and adhesives into the mixture of cements and soil gives better effectives. 2. After molding the porous planting blocks, it gave a better result when the grains of the filler made of peat moss, upland soil and compound fertilizer were smaller than 2 mm in size. Shaking of the filling materials also gave the better result, but it took more time and cost much more. Therefore, it was better when the filling materials were mixed with water first then flew down for stuffing. 3. It was necessary to cover with soil after seeding or planting on the porous planting blocks. The proper thickness of the soil to help root development and keep moisture is about 3~5 cm. 4. The plants for planting on the porous planting block were required stronger in the growth condition of their roots and their environmental adaptability. The average germination percentage and rate of Platycodon grandiflorum on the porous planting block were 88.8% and 85% accordingly and their rate is very uniform. The germination rates of Dianthus superbus var. longicalycinus and Taraxacum officinale were more than 50%. These grass species, Chelidonium majus var. asiaticum, Lysimachia mauritiana and Scabiosa mansenensis were the suggested biennial grasses in the planting area where exchanging of the seedling or nursery plants was not necessary because their germination rates were 59.3, 45.6 and 40.3% accordingly. Viola kapsanensis, Chrysanthemum sp., Taraxacum sp. and Iris ensata var. spontanea are the grass species that could be used by seeding for greening. However, the germination rate of Solidago virga-aurea var. asiatica, Aster scaber and Lythrum anceps were lower than 10%. The coverage ratio of Ixeris stolonifera is more than 80% after 60 days seeding and the root length of most of species are more than 10 cm except Iris ensata var. spontanea and Platycodon grandiflorum because their root developed thicker than other species.

• The Korean Journal of Pesticide Science
• /
• v.4 no.2
• /
• pp.37-43
• /
• 2000

Effects of silicon application on development of colonies of Sphaerotheca fuliginea were examined. Cucumber plants were applied with nutrient solutions amended with different concentrations of soluble silicon and selected leaves were inoculated with known concentrations of conidia of the pathogen. Colony number per leaf, colony area per leaf, and germination rate of conidia of S. fuliginea collected from the inoculated leaves were reduced as silicate concentrations in the nutrient solutions increased from 0.05 to 4.10 mM. The increase in resistance of plants to mildew infection was apparently due to silicate accumulation in leaves, and there was no correlation between cation or ionic strength effects and the silicate treatments. Silicate treatment in growth medium remarkably suppressed powdery mildew development on cucumber. Colonies of mildew fungus were visible with over approx. 38.3% of the mature leaf surface, while that of the leaves in high Si plants was 2.3% observed at 51 days after transplanting. No significant differences were observed between 1.7 mM and 3.4mM silicate treatments. Conidial germination rates were significantly reduced by increasing Si amendments. Conidial germination ranged from 14.7 to 20.3% for plants grown in low Si solution(<1.40 mM), and from 9.0 to 12.4% for plants grown in high Si solution(>1.8 mM). Foliar applications of Si with ${\geq}$ 17.0 mM decreased the number of powdery mildew colonies. Persistence of Si foliar sprays effects on cucumber demonstrated that the 17 mM Si spray applied 4 days before inoculation with S. fuliginea reduced mildew colony formation. The relationship was positive and linear.

• Korean Journal of Medicinal Crop Science
• /
• v.11 no.5
• /
• pp.347-351
• /
• 2003

This experiment was carried out to study the optimal chilling period for breaking the physiological dormancy of dehisced E. senticosus seeds and to investigate the critical seeding date in Kangwondo. Storage at $5^{\circ}C$ for 85 days was most effective in breaking dormancy of dehisced seeds, but didn't germinated synchronously. Only 28.1% of undehisced seeds germinated after 125 days of low temperature storage. For improving seedling survival rate in the field, 50% shading was more effective than 30% shading. Delayed seeding date resulted in decreased seedling fresh weight, dry weight, leaf area and root length, but seeding date has no significant affecte on stem length.