• Horticultural Science & Technology
• /
• v.33 no.5
• /
• pp.638-646
• /
• 2015

To increase the utility of seeds in plant resources, seeds of 6 Aster species(A. incisus, A. hayatae, A. koraiensis, A. scaber, A. spathulifolius, and A. yomena) were subjected to experiments to develop adequate methods for sprout production. To study optimum germination conditions, germination rates of the seeds were analyzed at different temperature (15, 20, 25, and $30^{\circ}C$) and light conditions. A longitudinal growth experiment was performed in dark conditions for 10 days. Seedlings, with optimum germination rate and longitudinal growth, were placed in the light for 0-3 days to seek the adequate greening periods. Sprouts grown under optimum environmental conditions were placed in vessels with or without ventilation, and stored under $4^{\circ}C$ and $10^{\circ}C$ to examine storage environment and period. As a result of this analysis, seeds were selected that germinated over 50% within 12 days. Longitudinal growth was promoted at $20-25^{\circ}C$, and optimum growth was obtained with 7-9 days. As greening days increased longitudinal growth was retarded, but orbital growth of radicles and cotyledons was promoted. Considering all these factors, greening treatment of 2 days showed the best results. In a storage ability experiment, the best result was achieved by storage in vessels without ventilation under $4^{\circ}C$. Ventilation prevented rotting of sprouts, but reduced moisture contents of sprouts. Most sprouts were fresh at $4^{\circ}C$ for 3-6 days. In particular, sprouts of A. hayatae and A. yomena had high keeping quality, and remained fresh over 3 days even at $10^{\circ}C$.

• Journal of Korean Society of Forest Science
• /
• v.79 no.2
• /
• pp.115-126
• /
• 1990

This study was performed to find differences in phototaxis response of the larva, adult emergence, sex ratio and gall formation rate of Thecodiplosis japonensis Uchida et Inouye between two areas, north and south. Larvae from these two areas, Hweng-sung in north and Moo-an in south, both considered to be the sities of severe outbreak of the insect recently, were collected from the floor and transported to the entomology larboratory, Won-Kwang University in Iri, then overwintered. These larvae were used for various experimental purposes on various dates. The following results were obtained. 1. The sizes of larvae reached 2.45 in length, 0.70 in width for north, and 2.50 in length, 0.72 in width for sourth. It seems that the differents were not significant. 2. It is known that Leaving gall of larvae to the ground for the hibernation usually occurs on rainy days. For the larvae dispersion, the phototaxis response of the larvae was hypothesized. To check this, the author manipulated some different illumination intensities adjusting the distance between the glass tube in which 100 larvae were contained and electric bulb. The glass tubes were blackened all but except a small portion. The phototaxis responses between two areas seemed to be different particularly at low light intensities, 45, 145 and 1000 lux, The larvae from north assembled to the clear portion of the glass tube were more than 30 out of 100, however less than 30 in south sample regardless of the time passage. In either cases, the saturation points came after about 8 to 10 hours. If temperature units were used, the phototaxis curve= after 1 hour illumination between two areas provided significant differences. 3. The adult emergence of south area was lagged 10 days later than that of north area. The accumulated effective day-degrees of temperature for adult emergence were $934^{\circ}C$ for north area and $1180^{\circ}C$ for south area. The emerging duration of north area appeared to be in late May through the early of July and the peak emergence occurred in middle June that was approximately 15days earlier than that of south area. The sex ratio of female to male, regardless of area, was approximately 3 : 1. 4. The rates of gall formation of the red pine(Pinus densiflora Siebold et Zuccarini), 6-year-old seedlings, were as low as 9.94% for north area and 8.87% for south area. Through the close observation, the author presumed that the population reduction was greatly affected during the prepupa stage by relative moisture content and predators, such as spiders and ants presented on the ground.

• Journal of agriculture & life science
• /
• v.46 no.1
• /
• pp.91-103
• /
• 2012

The aim of this study was to develop a rapid and cheap bioassay of four lignans (schisandrin, schisandrin C, the gomisin A and gomisin N) isolated from Schizandra chinensis Baill on seed germination and seedling growth of the radish. Its structure was determined by analysis of MS and NMR spectroscopic data. Radish seeds immersed for 1 hr in the solutions of $10^{-5}M$, $10^{-6}M$ and $10^{-7}M$ of schisandrin, schisandrin C, gomisin A, and gomisin N, seed germination was observed with in 60 hr after all of the treatments. Also, the seeds were germinated faster compared to untreated controls. At early germination stage, 48 hr after the treatment of the lignans, the suppression of germination was observed from all treatments; the suppression due to schisandrin and gomisin A was the highest at the concentration of $10^{-6}M$. The level of suppression increased as the concentration increased in the treatment of schisandrin C and gomisin N. Percent germination of seed after 184 hr was increased 90% at all treatments. For the effects of lignan treatment on seedling growth in radish, the growth of hypocotyl was promoted by gomisin A and gomisin N at all concentrations. Root elongation was significantly promoted by schisandrin and gomisin N at $10^{-5}M$ and $10^{-6}M$, respectively. Fresh and dry weights of the seedlings were high at a low concentration of $10^{-7}M$, but significantly reduced by schisandrin C at a high concentration of $10^{-5}M$. The results of the germination activity and seedling growth of the lignans from S. chinensis suggest their potential use as natural growth regulators.

• FLOWER RESEARCH JOURNAL
• /
• v.16 no.2
• /
• pp.112-117
• /
• 2008

Plug seedlings of vinca (Catharanthus roseus L. 'Pacifica Punch') and salvia (Salvia splendens F. Sellow ex Roem & Schult 'Maestro') were transplanted into square plastic pots (145 mL volume) filled with a soilless growing medium. To determine the effect of application rate on the growing medium EC and growth of plants, 0, 0.5, 1.0, 1.5, 2.0 and 4.0 g per pot of a controlled release fertilizer (14-14-14 Osmocote, 14N-6.2P-11.6K) were mixed with the growing medium. Plants were subirrigated daily with tap water. In both vinca and salvia, growing medium EC increased as application rate was elevated. Growing medium EC was relatively constant over a whole crop period when the application rate was less than 1.5 g per pot, while it decreased throughout the experiment at higher application rates such as 2.0 to 4.0g per pot in both species. The greatest leaf area, plant height, and shoot dry weight of vinca were obtained when plants were fertilized with 2.0 to 4.0 g per pot of the fertilizer, resulting in a growing medium EC of $1.0{\sim}1.7dS{\cdot}m^{-1}$ throughout the experiment. Leaf area, shoot dry weight, and chlorophyll content of salvia increased with elevated application rates. Leaf area, shoot dry weight, and chlorophyll content of salvia were the greatest when plants were fertilized with 4.0 g per pot, resulting in growing medium EC of $1.0{\sim}4.0dS{\cdot}m^{-1}$ throughout the experiment. Plant height of salvia was the greatest when plants were fertilized with 2.0 to 4.0g per pot. Concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and sulfur (S) in the shoots of vinca increased, while concentration of calcium (Ca) decreased with elevated application rates. Concentrations of boron (B) and manganese (Mn) in the shoots of vinca increased as the application rate decreased.

• Korean Journal of Plant Resources
• /
• v.13 no.3
• /
• pp.227-242
• /
• 2000

Site characteristics, vegetation structure and dynamics of Kalopanax septemlobus forests in Mt. Heungjeong, Mt. Balwang and Mt. Gariwang were studied to provide the information need for national resources conservation and restoration of K. septemlobus forest in Gangwon-do of Korea. The K. septemlobus forests were distributed at 780m to 1,300m in altitude, steep slope, ridges-slope areas with facing northeast to northwest in good nutrition area. The annual diameter growth of those trees ranged 1.60mm to 2.41mm. Forty-three plots(20$\times$20m) were set up at three natural population of Kalopanax septemlobus forest and TWINSPAN method was used for vegetation structure analysis. The result of TWINSPAN ordination show that geographical features played a role in determining community types in the study areas. Community type of the study areas classified into three groups by TWINSPAN; K. septemlobus-Quercux mongolica- Acer mono community(Mt. Balwang), K. septemlobus-Q. mongolica- Tilia amurensis community(Mt. Heungjeong), K. septemlobus-Betula costata-Q. mongolica community(Mt. Gariwang). In most of the K. septemlobus forests, major woody species appeared predominantly were Q. mongolica, T. amurensis, Acer pseudo-sieboldianum, Lindera obtusiloba, A. mono, Magnolia sieboldii, Ulmus davidiana var. japonica. And also, Those species were surveyed in all the areas. Species diversity(H') of investigated areas ranged 0.3124~0.13992 and this value relatively higher than that of other forests with similar site. The range of similarity indices between surveyed areas was 64.1~64.54%. The distribution pattern of Morista's index show that Kalopanax septemlobus distributed randomly in tree and concentrated a few sample plots in subtree layer and shurb layer. K. septemlobus occupied 37.1~58.8% of tree layer story, 8.4~17.6% of subtree layer, 0~0.38% of shurb layer each surveyed area. The association analysis showed that Kalopanax septemlobus positively associated with Betula ermani, Deutzia glabrata, Carpinus cordata, Fraxinus mandshurica and negatively associated with Symplocos chinensis var. pilosa, Styrax obassia, Acer mono, Euonymus macroptera, Ulmus davidiana var. japonica. According to the diameter distribution of Kalopanax septemlobus community, the community of Mt. Gariwang will gradually decline and replaced by Quercus community. The communities of Mt. Heungjeong and Mt. Balwang has its seedlings and saplings, so it may be sustained.

• Korean Journal of Soil Science and Fertilizer
• /
• v.44 no.3
• /
• pp.465-472
• /
• 2011

To investigate the effect of inorganic ($GeO_2$) and organic (Ge-132) germanium treatment on Brasica juncea C. plant, growth characteristics and Ge contents were examined with various inorganic or organic germanium treatments (0, 5, 10, 25, 50, 75 and $100mg\;L^{-1}$), respectively. Brasica juncea C. growth did not much inhibited until Ge $10mg\;L^{-1}$ concentration under both Ge-132 and $GeO_2$ treatments as compared to control. On the other hand, at Ge concentration higher than $25mg\;L^{-1}$ concentration, Brasica juncea C. growth was inhibited under both Ge-132 and $GeO_2$ treatments. Under treatment of $GeO_2$, length of root and shoot slightly increased until $5mg\;L^{-1}$ concentration and dry weight slightly increased until $10mg\;L^{-1}$ concentration. Under treatment of Ge-132, length of root and shoot slightly increased until $10mg\;L^{-1}$ concentration and dry weight slightly increased until $25mg\;L^{-1}$ concentration. Total Ge contents in Brasica juncea C. early seedlings with $GeO_2$ treatment were a bit higher than those with Ge-132 treatment. Germanium was primarily accumulated in the roots (77%) with organic Ge (Ge-132) treatments, whereas Ge was primarily accumulated in the leaf (70%, respectively) with $GeO_2$ treatments. The Ge uptake rates in inorganic Ge treatments were slightly high than those in organic Ge treatments. Under inorganic Ge treatment with $2.5mg\;L^{-1}$, about 3% of Ge was accumulated into plant and distribution in leaf and root was 84.8% and 15.2%, respectively. Under organic Ge treatment with $2.5mg\;L^{-1}$, about 2.6% of Ge was accumulated into plant and distribution in leaf and root was 66.4% and 33.6%, respectively.

• Korean journal of applied entomology
• /
• v.60 no.4
• /
• pp.387-401
• /
• 2021

Thrips infesting hot peppers were monitored in greenhouses using yellow sticky traps. In addition, the hot peppers infected with tomato spotted wilt virus (TSWV) were observed during the monitoring period. The flower thrips (Frankliniella intonsa) were initially trapped at a low density just after transplanting seedlings of hot peppers at late March. The western flower thrips (Frankliniella occidentalis) were trapped after mid April. These two thrips represented more than 98% of the total thrips attracted to the traps after May, in which F. intonsa showed higher occurrence frequency than F. occidentalis. The total number of thrips had two peaks at mid May with a small and short-term peak and at June-July with a large and long-term peak. The trapped thrips exhibited inconsistent sex ratios, suggesting a seasonal parthenogenesis. Different geographical populations were varied in cytochrome oxidase I sequences, in which local populations in Andong shared a high sequence similarity. TSWV-infected hot peppers, which might be mediated by these two thrips species, were observed and confirmed by an immunoassay kit and a molecular diagnosis using RT-PCR. In addition, the TSWV was detected in F. occidentalis collected from the infected hot peppers. Three open reading frames (NS_S, N, and NS_M) of the isolated TSWV genomes were sequenced and showed multiple point mutations containing missense mutations among geographical variants. When the isolated TSWV was fed to nonvirulent thrips of F. occidentalis, the virus was detected in both larvae and adults. However, the viral replication occurred in larvae, but not in adults.

• Journal of Bio-Environment Control
• /
• v.30 no.3
• /
• pp.237-243
• /
• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Journal of Bio-Environment Control
• /
• v.30 no.3
• /
• pp.196-205
• /
• 2021

This research was conducted in order to analyze the difference in yield through the changes in growth and measuring the photosynthesis efficiency in cherry tomatoes. Seedlings of cherry tomato 'Nonari' were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. Plants grafted onto 'B.blocking' produced the highest fruit yield (417.5 g plant^-1), whereas non-grafted plant 'Nonari' had the lowest fruit yield, (354.2 g plant^-1) at the latter period of cherry tomatoes in May. The flowering position in May, plant grafted onto 'B.blocking', showed 14-17 cm, whereas non-grafted plant 'Nonari' showed 10-14 cm. The growth strength on May 15, non-grafted plant 'Nonari', showed 8.43 mm which was the lowest value among the treatments. Grafted plants kept the growth balance until the end of the harvest that led to an increase in fruit yield, while non-grafted plant weakened the vigor earlier that led to a decrease in fruit yield. Grafted plants showed higher values of chlorophyll fluorescence variables than the values of non-grafted plant. These results indicate that grafting influenced fruit yield which was observed as maintaining growth balance for longer and an increase in photosynthesis efficiency compared to non-grafting.

• Korean Journal of Environment and Ecology
• /
• v.33 no.4
• /
• pp.422-439
• /
• 2019

The rear edge population is considered to have low genetic diversity and high risk of extinction according to a highly isolated distribution. However, the rear edge population is observed to have persisted for an extended period despite the low genetic diversity. As such, it is necessary to understand the ecological process involved in the persistence of the population. Viola mirabilis L. in Korea is considered the rear edge population from the perspective of the worldwide distribution. We surveyed the distribution range of V. mirabilis, which shows the isolated distribution in the central area of Korea, to find out the factors of its persistence. Next, we investigated and accessed the vegetational pattern of habitats, soil environment, phenology, self-compatibility, population structure, and extinction risk factors observed in the distribution area. V. mirabilis was distributed in the understory of the deciduous forest, planted forest of the deciduous conifer and deciduous broad-leaved trees, shrubland, and grassland in the limestone area. We also observed the re-establishment of seedlings in the population, and most of them showed a stable population structure. For chasmogamous flowers, the visit by pollinators has a significantly positive relationship with the production of fruits. However, we found that the production of the cleistogamous flowers was more numerous in all studied populations and that only the cleistogamous flowers were produced despite a more substantial plant size in some populations. The plant size was more related to the production of the cleistogamous flowers than that of the chasmogamous flowers. Accordingly, the cleistogamous flowers significantly contributed to seedling recruitment in the population. We found that the production of the chasmogamous flowers and the cleistogamous flowers did not have a correlation with the factors of the soil analysis except for phosphoric acid. V. mirabilis showed the self-incompatibility characteristics most likely due to the production capability of the cleistogamous flowers. Potential extinction risk factors observed in the distribution area was included the development of limestone mine, the expansion of agricultural fields, and the construction of houses. Although V. mirabilis showed an isolated distribution in the limestone area in the Korean peninsula, it showed a diverse distribution in a wide habitat environment ranging from the grassland to the understory of the trees with relatively low canopy closure rate. Moreover, we concluded that the persistence of the population was possible if we can maintain the current state of multiple populations and stable population structure.