• Journal of Plant Biotechnology
• /
• v.30 no.2
• /
• pp.201-206
• /
• 2003

Differential responses of red pepper plant and cultured cells to enhanced ${\gamma}$-ray($^{60}$ Co) and ultraviolet(UV) stress were investigated. In seed treatment, 1 Gy of ${\gamma}$-ray increased seedling dry weight up to 19.1%, but 50 Gy treatment markedly ingibited seed germination and subsequent growth of seedling. UV treatment to seed did not change the germination ability of seeds and the growth of seedlings regardless of duration of UV treatment until 24 hrs. In case of UV treatment to seedlings, plant injury was seriously progressed even after the seedlings were returned to no UV condition, and eventually all the leaves showed chlorosis by the stress. However, progress of plant injury by ${\gamma}$-ray stress slower than that caused by UV stress, and even at the high dose of ${\gamma}$-ray 50 Gy, did not caused the cholrosis of stressed plant leaf. Amount of electrolytes leakage from plant leaf by UV treatment for 24hrs was increased up to 28.8 folds in comparison with untreated control, whereas that of 50 Gy of ${\gamma}$-ray was increased only 1.2 folds. UV stress induced the production of capsidiol, antimicrobial phytoalexin, by activation of gene expression involved in capsidiol biosynthesis, such as sesquiterpene cyclase and cyclase and cytochrome P450 hydroxylase in the leaf and cultured cell, but ${\gamma}$-ray stress induced neither the production of capsidiol nor expression of the genes.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.189-189
• /
• 2017

Salinity is one of the major abiotic stresses that severely affect crop production throughout the world; especially rice plant which is generally categorized as a typical glycophyte as it cannot grow in the presence of salinity. Phenotypic resistance of salinity is expressed as the ability to survive and grow in a salinity condition. Salinity resistance has, at least implicitly, been treated as a single trait. Physiological studies of rice suggest that a range of characteristics (such as low shoot sodium concentration, compartmentation of salt in older rather than younger leaves, high potassium concentration, high $K^+/Na^+$ ratio, high biomass and plant vigour) would increase the ability of the plant to cope with salinity. Criteria for evaluating and screening salinity tolerance in crop plants vary depending on the level and duration of salt stress and the plant developmental stage. Plant growth responses to salinity vary with plant life cycle; critical stages sensitive to salinity are germination, seedling establishment and flowering. We have established a standard protocol to evaluate large rice germplasms for overall performance based on specific physiological traits for salt tolerance at seedling stage. This protocol will help in identifying germplasms which can perform better in the presence of different salinity treatments based on single trait and also combination of different physiological traits. The salt tolerant germplasm can be taken forward into developing better varieties by conventional breeding and exploring genes for salt tolerance.

• Journal of Environmental Science International
• /
• v.18 no.10
• /
• pp.1163-1170
• /
• 2009

The clam, Gomphina melanaegis, which is commonly called the sandy beach clam because of its habitat, is a valuable organism in the sandy coast of East Sea, Korea. It is frequently observed in large populations between 0.5 and 5 meters. We have released 50,000 seedling, ranging from the diameter of approximately 3 mm, 2007, and 1,000,000 seedling, ranging from the diameter of approximately 0.2 mm, plus 100,000 adult individuals, ranging from the shell length of approximately 20~40 mm, 2008 at Jinha beach. The spawning period of G. melanaegis, was from June to August, and the main spawning occurred in July. This investigation was carried out to elucidate population distribution on the stocking area of sandy beach clam, G. melanaegis. The relationship between shell length and ring radius in each ring was investigated as a regression line. The relationship between the shell length and shell height of released young clam was SH=1.0105SL-4.7764 ($R^2=0.7905$). The relationship between the shell length and total weight of released young clam was $TW=0.0013SL^{2.3966}$($R^2=0.71$). It draws a deduction that the ring of this clam was produced once a year during the duration between June and August.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.3
• /
• pp.215-222
• /
• 2008

Multilocation trials on 36 rice(Oryza sativa) genotypes of 3 different maturity groups were conducted at four different locations of Orissa for 3 years and 30 ragi(Eleusine coracana) genotypes of 2 different maturity groups were evaluated in three environmental conditions for 3 years. Grain yield data were subjected to stability analysis following linear regression model to estimate adaptability and stability parameters, i.e. b, and $S^2d$ Stability of performance of genotypes was also estimated by two other stability parameters viz., ecovalence W and AMMI stability value ASV. The rice and ragi genotypes of different duration groups showed wide variation in their mean yield, b, $S^2d$, W and ASV parameters. Seeds of the 36 rice and 30 ragi genotypes were treated with 500 and 100 ppm aqueous solution of maleic hydrazide(MH) for 24 hours, respectively to study MH-sensitivity. Sensitivity of genotypes to MH treatment was estimated in terms of seedling growth inhibition index(SGI). The rice and ragi genotypes showed wide differences in their MH-sensitivity in terms of SGI. Relationship of MH-sensitivity of genotypes with their yielding ability, adaptability and stability of performance was tested by contingency $x^2$ test. Low sensitivity of rice and ragi genotypes to MH in terms of SGI appeared to be good indicators of high yielding ability of genotypes. Also, low and high MH-sensitivity of genotypes would be a good indicator of better adaptability to rich and poor environments, respectively, in ragi but not in rice. Low MH-sensitivity of genotypes could be the good indicator of stability of yield performance in rice but not in ragi.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.24 no.1
• /
• pp.11-24
• /
• 1979

To characterize elastic and plastic chilling injury, rice seedlings grown at 28/$16^{\circ}C$ day/night temp. under 20K lux (13hrs.) in a phytotron were subjected to a 11/$6^{\circ}C$, 20K lux condition for 2, 4, 6 or 8 days at 1, 2, 3, 4 or 5th leaf-stage, respectively, followed by further growth under 28/$16^{\circ}C$condition till 30th day after seeding. Japonica variety Jinheung and Chulwon No.1 survived almost 100% without any significant , discoloration and death of leaves due to chilling even under the chilling of 8 days at all seedling ages tested. Tongil and Yushin, varieties from Indica x Japonica cross, showed increasing discoloration of leaves and death of plants with increase in chilling intensity. The longest chilling duration shown seedling death less than 5% was 4, 6, 1, 4, 8 days for Tongil, and 6, 6, 1, 2, 2, days for Yushin at 1, 2, 3, 5th leaf-stage, respectively. The degree of discoloration and death of leaves or suppression of height growth was not explicitly related to seedling death or the dry weight reduction. The degree of seedling death or dry weight reduction could differentiate chilling tolerance of varieties and seedling ages, but somewhat differently. Reduction in dry weight due to chilling occurred even without any visible injury or seedling death. These suggest that both the degree of seedling death and reduction in dry weight should be considered in the test of varieties for chilling tolerance. Combined evaluation of seedling death and dry weight reduction indicated the most susceptible seedling age to chilling injury to be 1 to 2nd leaf-stage for Jinheung, 2 to 3rd leaf-stage for Chulwon No.1, 3rd leaf- stage for Tongil and Yushin, respectively.

• Journal of Life Science
• /
• v.18 no.2
• /
• pp.154-161
• /
• 2008

The physiological and photochemical responses of rice seedling to NaCl stress were investigated through measuring leaf relative water content (RWC), root water uptake and chlorophyll fluorescence. When plants were exposed to increased salinity stress, the visual symptoms of injury were significant at ${\geq}$500 mM NaCl concentration for 4 and 5 day stress periods. The differences in Fv/Fm between control treatment and plants treated with 500 mM and 1,000 mM NaCl were evident after 5 day and 4 day, respectively, whereas in root water uptake its effect was observed at 500 mM and 1,000 mM NaCl at 2 day of salt-stressed periods. Leaf RWC in salt-stressed plants decreased gradually with increasing salinity in exogenous solution and duration of salt stress, and these decrease showed leaf RWC of 58-68% atduration over 2 day stress of 1,000 mM NaCl treatment and 88% at 1 day stress. NaCl stress led to a significant inhibition of the light-induced greening in etiolated rice plants, especially in 4 and 5 day salt-stressed plants, which linearly decreased with NaCl concentration ($R^2$=0.812 and 0.918, respectively). The effects of NaCl stress in rice seedlings indicate that water uptake in root is more sensitive to increasing NaCl concentration and stress duration than Fv /Fm in leaves compared with the same NaCl concentration.

• Korean Journal of Medicinal Crop Science
• /
• v.11 no.2
• /
• pp.155-160
• /
• 2003

This study was carried out to investigate propagation characteristics of seedling and rhizome in Epimedium koreanum NAKAI. Seed germination essentially needed after-ripening duration after harvesting for 250days and more by stratification. At $20^{\circ}C$ seed emergence days and root length were 8 and 0.46cm respectively. The above-ground part of E. koreanum grew until 60days after root cutting and the underground part of it grew after that time. The optimum amount of organic fertilizer was fermented cow-manure with husk 2,000kg/10a that showed $57.5cm^2$ in leaf area per plant, 6.2cm in new rhizome length, and 0.43% in icariin content, an index component of E. koreanum, while inorganic N-fertilizer made E. koreanum worse as it increased. In nutriculture extruded rice hull media was better for growth than perlite media at 1/2 NHRI solution.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.42 no.1
• /
• pp.14-21
• /
• 1997

This experiment was conducted to identify the growth and yield differences in rice cultural types: Broadcasting on flooded paddy surface(BF), drilling on flooded paddy surface(DF), puddled-soil drill seeding(PD), drill seeding on dried paddy flat(DD), and machine transplanting of lO-day old seedling(MT) at National Honam Agricultural Experiment Station in 1995. Among the cultural types of direct seeding, the number of seedling stand showed high in order of DD>BF>DF>PD. Tillering at early growth stage was faster in MT and effective tiller showed higher in MT than in direct seeding. Growth duration from seeding to heading was longer in direct seeding than in MT for 2-13 days of Dongjinbyeo and 10-18 days of Nonganbyeo. Root distribution ratio at the surface soil revealed high in order of BF>DF>PD>DD and MT. Culm wall thickness of 4th internode was thicker in machine transplanting of 10-day old seedling than in direct seeding, and the depth of buried culm showed deep by turns of MT> DD>PD>DF and BF. The height of center gravity and moment related to lodging revealed higher in direct seeding than machine transplanting that resulted high lodging index by turns of BF>DF>DD> PD among the direct seeding cultural type. Lodging was occured seriously in the order of BF>DF>PD>DD =MT in Dongjinbyeo but wasn't significantly different in Nonganbyeo among the cultural type. The yield components and grain yield showed varietal differences but was not significantly different between in MT and in direct seeding, and among cultural types of direct seeding.

• Korean Journal of Medicinal Crop Science
• /
• v.24 no.6
• /
• pp.479-485
• /
• 2016

Background: Planting vigorous cuttings that quickly develop shoots and roots is essential to the biological and economic success of producing medicinal flowers. The present study aimed to evaluate the effect of storage temperature and duration on seedling capacity in the propagation of Chrysanthemum indicum L. and to investigate the effect of rooting media on the growth of C. indicum L. after cutting. Methods and Results: Returning cuttings to supplemental cold storage ($2.0{\pm}1.0^{\circ}C$) may extend duration of cutting viability 6 weeks, returning cuttings to supplemental warm storage ($25.0{\pm}1.0^{\circ}C$) is not recommended. The treatment of the growing media experiments, which were conducted in the 2014 planting seasons, included sawdust, river sand, topsoil + sawdust, topsoil + poultry manure, sawdust + river sand, river sand + poultry manure, topsoil + river sand + poultry manure, topsoil + poultry manure + river sand + sawdust. Result indicated that the topsoil + poultry manure media performed best and supported the highest number of branches (3.47), branch length (26.39), and number of leaves (88.63). Conclusions: The results of the present study suggest that cold storage and the topsoil + poultry manure growth media was superior in supporting the early establishment of C. indicum cutting, this result will have a tremendous influence on propagation of this species.

• Journal of the Korean Society of International Agriculture
• /
• v.23 no.5
• /
• pp.520-530
• /
• 2011

This study was carried out to evaluate the possibility of rice double cropping in Korea by assessing the growth and yield performance of rice cultivars transplanted at the extremely-early date. When the transplanted rice seedling was exposed to low temperature below 0℃, the survival rate decreased drastically. However, short exposure to below 0℃ one or two times did not damage transplanted rice seedling so severely. Thus, the earliest transplanting in spring would be possible when minimum temperature rises above 0℃. Compared with the conventional seedling nursery tray (CSNT), seedling rearing with the potted nursery tray was more effective for increasing leaf age and seedling dry weight during nursery period. In the first rice cropping, rice cultivation with seedlings reared in PSNT showed shorter growth duration and cumulative temperature from transplanting to heading than that with seedlings reared in CSNT. The earliest heading date on July 4 in Jinbuolbyeo was earlier by two to three days than that of Dunaebyeo. If rice has not exposed to cold damage, the earliest heading date of Jinbujolbyeo can advance to June 30 or July 1. In this case, rice harvest would be possible on August 5, enabling the rice transplanting of the second rice cropping before August 10. At transplanting time with low temperature damage rice yield were less than 400 kg/10a while rice yield exceeded 400 kg/10a at transplanting time without low temperature damage.