• Journal of The Korean Society of Grassland and Forage Science
• /
• v.39 no.3
• /
• pp.153-157
• /
• 2019

Salicylic acid (SA) is an essential plant growth regulator that functions as a signaling molecule in plants. The purpose of this study was to clarify how the exogenous application of SA counteracts aluminum stress-induced growth and biomass yield reduction in alfalfa exposed to aluminum (Al) stress. Two-week-old alfalfa seedlings were exposed to a combination of $AlCl_3$ ($0{\mu}M$, $50{\mu}M$ and $100{\mu}M$, respectively) and SA (0.1 mM) for 72 hours. We observed, Al stress-induced plant growth inhibition and forage yield reduction are Al stress-dependent manner. A significant reduction of plant height (42.0-52.9%), leaf relative water content (13.0-21.4%), root length (35.4-48.7%), shoot fresh weight (31.2-25.9%), root fresh weight (15.4-23.3%), shoot dry weight (12.7-22.2%), roots dry weight (47.3-53.5%), were observed in alfalfa. In contrast, SA alleviated the Al-stress and enhanced growth and biomass yield in alfalfa. This study provides useful information concerning the role of SA that counteracts aluminum stress-induced growth and yield reduction in alfalfa.

• Journal of Bio-Environment Control
• /
• v.18 no.4
• /
• pp.303-308
• /
• 2009

This study was conducted to analyze the feasibility of plant growth under low pressure and to investigate the effect of pressure on plant growth. Three levels of pressures (25, 50, and 101.3 kPa (control)) were provided to analyze the growth of Lettuce (Lactuca sativa L.) as affected by low pressure. Photoperiod, air temperature, and photosynthetic photon flux were set at 16/8 h, 26/$18^{\circ}C$, and $240{\mu}mol{\cdot}m^{-2}s^{-1}$, respectively. Growth characteristics of lettuce were measured on 7 days and 14 days after experiment. Leaf length, leaf width, leaf area, and root dry weight of lettuce measured on 7 days under 25 and 50 kPa were significant as compared to the control. Leaf length, top dry matter and root dry matter of lettuce measured on 14 days were significantly different under 25 and 50 kPa. From these results, we confirmed that lettuce could be grown under low pressure. However high relative humidity by evapotranspiration from leaves and growing beds under low pressure caused the condensation on the inner surface of the chamber. Therefore in a low pressure chamber, humidity control is required to maintain the relative humidity at a proper level.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.302-302
• /
• 2017

This study was conducted to evaluated the effects of different sowing time(October 22, February 20, March 3, March 13, and March 23) and sowing quantities(150kg/ha, 200kg/ha, 250kg/ha, and 300kg/ha) on growth of naked oat(Avena sativa L.) cultivar(Choyang-Gwiri) at a cultivation area in Iksan, south Korea. Heading times were delayed with later sowing times. In autumn seeding(Oct. 22) the ear was headed at April 30, in spring seeding(Feb. 20, Mar. 3, Mar. 13, and Mar. 23) heading times were respectively May 14, May 14, May 15, and May 19. Heading time of spring seeding was delayed about 3 weeks than autumn seeding. Ripening times were similar trends to the heading times. In autumn seeding ears were ripened at June 7, in spring seeding each times were respectively Jun. 15, Jun. 13, Jun. 20, and Jun. 20. Ripening time of spring seeding was delayed about 2 weeks than autumn seeding. Culm length and ear length were shortened in spring seeding, but number of plants per $m^2$ were increased. Number of grains per a ear were 106 in autumn seeding, but grains per a ear in spring seeding were respectively 88, 83, 83, and 73. Weight of 1,000 grains in spring seeding was heavier than that in autumn seeding, the weights were tend to light as later seeding times. Yield of grains was declined as later seeding times, yield of in autumn seeding was 2,900kg/ha, whereas that in spring seeding was 2,180kg/ha. The highest yield of spring seeding time was in Mar. 13, before this seeding time soil surfaces were severely dried as few rain fall, so germination was poor in those seeding times. As several seeding quantities were seeding, earing and ripening times were not different. but increasing seeding quantity, culm length was lengthened and ear length was shortened, number of plants per $m^2$ were increased and grains per a ear were reduced. Yield of grains were increased more seeding quantities, yield was highest up to 250kg/ha seeding quantity.

• Korean Journal of Soil Science and Fertilizer
• /
• v.25 no.1
• /
• pp.57-61
• /
• 1992

For testing salts effect on seed germination, nitrogen solutions($(NH_4)_2SO_4$, $NH_4NO_3$, $KNO_3$, $Mg(NO_3)_2$, $Ca(NO_3)_2$, $(NH_2)_2CO$) were treated to chinese cabbage(Brassica rape L.) and lettuce(Lactuca sativa L.) seeding on the quartz sand bed given a tilt to wet by dripping. Electrical conductivities (mS/cm) increased with direct proportion by equivalent gram-molecular weight at $(NH_4)_2SO_4$ and $KNO_3$, $NH_4NO_3$, but those of Mg and Ca salt remained 1 1/2 times higher. And urea solution never showed EC at all. $(NH_4)_2SO_4$ solution appeared to have value of EC with 1.37 times as high as that of $KNO_3$ and it was in order of $(NH_4)_2SO_4>NH_4NO_3>KNO_3>Ca(NO_3)_2>Mg(NO_3)_2$ comparing with same percentage solution. Application of $Mg(NO_3)_2$ and $(NH_4)_2SO_4$ among 6 salts resulted in a severe decreas in germination of both crops, and $NH_4NO_3$ showed light inhibition in comparison to $KNO_3$. Urea showed little effect on germination as the same as $Ca(NO_3)_2$ and $KNO_3$ solution at low concentrations, but the latter two salts reduced germination remarkably at high concentrations. It is likely to show that germination inhibition is not affected by salt salanity but by the sort of salts.

• Applied Biological Chemistry
• /
• v.39 no.4
• /
• pp.297-303
• /
• 1996

A series of the herbicidal N-(4,6-disubstituted pyrimidin-2-yl)aminocarbonyl-2-(1,1-ethylenedioxy-2-fluoro)ethyIbenzenesulfonamides, 1 and N-(4,6-disubstituted triazin-2-yl)aminocarbonyl-2-(1,1-ethylenodioxy-2-flu ore)ethylbenzenosuIfonamides, 2 were synthesized and their herbicidal activities in-vivo against rice(Oryza sativa L.), barnyard grass (Echinochloa crus-galli), bulrush(Scripus juncoides) and pickerel weed(Monochoria vaginalis presl.) were measured by the pot test under the paddy conditions. The structure activity relationships(SAR) between the herbicidal activity$(pI_{50})$ and a various physicochemical parameters of the hetero group and 4,6-disubstituents on the heterocyclic group were analyzed by the multiple regression technique. The SAR suggest that the 4,6-dimethoxypyrimidine substituent, 1a showed selective$({\Delta}obs.pI_{50}=1.12)$ and the most highest activity against barnyard grass, which depend on the hydrophobicity(log P<0) of heterocyclo group and molecular refractivity$((M_R)_{opt.}=14.58cm^3/mol)$ constant of 4,6-disubstituents on the heterocyclic group.

• Horticultural Science & Technology
• /
• v.32 no.3
• /
• pp.330-339
• /
• 2014

Growth and anthocyanins of lettuce (Lactuca sativa L., 'Mid-season') grown under LED lamps with blue light in the range of 430-470 nm or with red light in the range of 630-670 nm were analyzed in this study. Cool-white fluorescent light was used a s the control. P hotosynthetic photon flux, p hotoperiod, air temperature, relative humidity, and $CO_2$ concentration in a closed plant production system were $201{\pm}2\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 16/8 hours (day/night), $22/18^{\circ}C$, 70%, and $400{\mu}mol{\cdot}mol^{-1}$, respectively. At 21 days after light quality treatment, growth characteristics and anthocyanins content of lettuce as affected by the peak wavelength of blue or red LED were significantly different. Among peak wavelengths treated in this stusy, R1 treatment (peak wavelength 634 nm) and R6 treatment (peak wavelength 659 nm) were effective for increasing leaf width, leaf area, shoot fresh weight, and photosynthetic rate of lettuce. B5 treatment (peak wavelength 450 nm) and B4 treatment (peak wavelength 446 nm) increased the anthocyanins concentration and chlorophyll content in lettuce leaves, respectively. Anthocyanins in lettuce leaves increased linearly with decreasing hue value of leaf color and with increasing SPAD value of lettuce leaves. From these results, it was concluded that the red LED with peak wavelengths of 634 nm and 659 nm and the blue LED with peak wavelengths of 450 nm can be used as potential light spectra for increasing the yield and anthocyanins accumulation of leafy vegetable.

• Journal of Nutrition and Health
• /
• v.56 no.4
• /
• pp.361-376
• /
• 2023

Purpose: This study evaluates the potential protective effects of hemp (Cannabis sativa L.) seed oil supplementation in rats fed a high-cholesterol diet. Methods: Rats were fed a 1.25% cholesterol diet for 8 weeks, followed by oral administration of either of the two doses of hemp seed oil (HO) (0.5 mL/kg (HOL group) or 1 mL/kg (HOH group) body weight/day) or simvastatin at 10 mg/kg body weight/day. Oxidative stress, lipids, liver enzymes, and renal markers were measured in the serum. Western blot analysis was applied for evaluating the expressions of inflammatory makers. Results: Except for HDL-cholesterol, the altered levels of lipoproteins, aminotransferases, urea, and creatine kinases in hypercholesterolemic rats were significantly corrected by HO administration. Especially, compared to the HOH group, HOL treatment further reduced AST, ALT, creatinine, TC, and LDL-cholesterol levels. Moreover, both the atherogenic index and cardiac risk factor (CRF) in the HOL group were more restrained compared to the HOH group. Increased levels of p-AMPK coincided with the inhibition of SREBP-2 activation which subsequently suppressed the expression of HMGCR. Nuclear factor (NF)-κB activation coincided with the PI3K/Akt pathway activation and the increased phosphorylation of p38; these levels were significantly suppressed by HO treatment. In addition, HO treatment markedly reversed the changes in chemokines such as ICAM-1, VCAM-1, and MCP-1. Histological alterations induced by cholesterol overload in cardiac and hepatic tissues were ameliorated by HO supplementation. Conclusion: Taken together, our results indicate a low concentration of HO demonstrates improved dysfunctions caused by a high-cholesterol diet via inhibition of the PI3K/Akt/NF-κB signaling pathway.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.7
• /
• pp.929-934
• /
• 2000

Optimum stand density of alfalfa (Medicago sativa L.) varies with locations and climates. Stand density is one of the factors that determines herbage yield, forage quality and persistence of alfalfa. As establishment costs increase, the question arises whether present population densities are optimum for obtaining maximum herbage yield and forage quality. The objectives of this study were: 1) to determine the optimum plant density for highest herbage yield and forage quality for the dehydrated alfalfa industry under Edmontons climatic conditions in Alberta, Canada; 2) to compare herbage yield and forage quality of the cultivars 'Algonquin' and 'Vernal' grown at a range of stand densities. Alfalfa seedlings of both cultivars were either transplanted at spacings of 6, 10, 15 and 25 cm or direct seeded at the 4.5 cm plant spacings, providing population densities of 494, 278, 100, 45 and $16plants/m^2$. The experimental design was a randomized complete block with a split-plot arrangement having three replicates; the main plots consisted of two alfalfa cultivars Algonquin and Vernal, and the sub-plots were the five population densities. The cultivar Vernal had significantly higher annual yield than did the cultivar Algonquin. There was no significant effect of plant density on herbage yield. There was no difference in crude protein (CP) between the two cultivars. At the first cut, there was a significant quadratic effect of plant density on CP content and the greatest CP occurred at the 100 plants/m2 density. Crude protein was not affected by plant density at the second cut. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were not affected by plant density. The cultivar Algonquin usually had a lower ADF and NDF than cultivar Vernal. In conclusion, high population densities ($278plants/m^2$ or more) of alfalfa did not improve herbage yield and forage quality compared with low plant population densities ($100plants/m^2$ or less) of alfalfa.

• Journal of Plant Biotechnology
• /
• v.5 no.1
• /
• pp.43-49
• /
• 2003

Resistant cell lines to azetidine-2-carboxylic acid (AZCA) were selected through rice embryo culture after mutagenic treatment of callus irradiated with 30,50,70,90 and 120 Gy. The optimum AZCA concentration for the selection of resistant cell lines was 3 or 4 mM AZCA considering $LD_{50}$ and the fresh weight of callus. Survival rate of the AZCA resistant callus showed remarkable increase in the callus irradiated with 50 and 70 Gy. Regeneration rate of the AZCA resistant callus was much lower on the whole. Ninety and 120 Gy increased the regeneration rate for calli selected from 3 and 4 mM AZCA, respectively. Based on fresh weight, survival rate and regeneration for selection of the AZCA resistant cell line, 50-90 Gy was considered as the optimum range of gamma irradiation. Irradiated calli selected from AZCA were more tolerant to NaCl than those from non-irradiated calli. It suggests that elevated resistance to osmotic stress resulted from mutagenic treatment. The level of free proline content in the AZCA resistant cell line was increased up to 3.5 times compared with that in the control. Proline content in the regenerant derived from the AZCA resistant cell line also increased to 1.7 times that from the control plants regenerated from callus grown in AZCA free medium. Selection of proline overproducing cell lines by in vitro mutagenesis was successful and seems to be useful for improvement of stress tolerance in this crop.

• Journal of Crop Science and Biotechnology
• /
• v.10 no.4
• /
• pp.257-264
• /
• 2007

Rice is one of the world's staple crops and is a major source of carbohydrate. Rice is exported from several countries, providing a major source of income. There are many documents reporting that rice is a salt-sensitive crop in its developmental stages. The objective of this investigation is to evaluate the effective salt-tolerance defense mechanisms in aromatic rice varieties. Pathumthani 1(PT1), Jasmine(KDML105), and Homjan(HJ) aromatic rice varieties were chosen as plant materials. Rice seedlings photoautotrophically grown in-vitro were treated with 0, 85, 171, 256, 342, and 427 mM NaCl in the media. Data, including sodium ion$(Na^+)$ and potassium ion$(K^+)$ accumulation, osmolarity, chlorophyll pigment concentration, and the fresh and dry weights of seedlings were collected after salt-treatment for 5 days. $Na^+$ in salt-stressed seedlings gradually accumulated, while $K^+$ decreased, especially in the 342-427 mM NaCl salt treatments. The $Na^+$ accumulation in both salt-stressed root and leaf tissues was positively related to osmolarity, leading to chlorophyll degradation. In the case of the different rice varieties, the results showed that the HJ variety was identified as being salt-tolerant, maintaining root and shoot osmolarities as well as pigment stabilization when exposed to salt stress or $Na^+$ enrichment in the cells. On the other hand, PT1 and KDML105 varieties were classified as salt-sensitive, determined by chlorophyll degradation using Hierarchical cluster analysis. In conclusion, the HJ-salt tolerant variety should be further utilized as a parental line or genetic resource in breeding programs because of the osmoregulation defensive response to salt-stress.