• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.3
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• pp.248-253
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• 2017

Humic acid (HA) is known to consist of various kinds of polymeric organics, their detailed structures can vary depend on sample sources such as organic manure, composts, peat, and lignite brown coal, and largely exists in grassland soils. HA possesses diverse positive effects that not only increase plant growth but also improve soil fertility. Recently, we have manufactured a co-polymeric product of catechol and vanillic acid (CAVA) synthesized artificially, and found that CAVA as a HA mimic increases seed germination and salt tolerance in Arabidopsis. In this study, we examined whether HA or CAVA affects to seedling growth in alfalfa. Foliar application of HA or CAVA increased alfalfa seedling growth including aerial and in root parts. HA or CAVA dramatically enhanced size of leaf and root, whereas HA significantly displayed higher bioactivity than CAVA. Taken together, CAVA acts like as a HA mimic in alfalfa that could apply as an alternation supplement to enhance plant growth and productivity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.48-54
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• 1989

This study was conducted to select the best adapted alfalfa cultivars among 32 introduced alfalfa cultivars in the Korean environmental condition. Plant height and dry matter yield per cultivar were determined. On the point of plant height, seven high ranked cultivars among the 32 alfalfa cultivars in high order were Diamond> Milkmaker> Arrow>Chalienger>Sapphire > Dekalb brand 135> LS-1920. and seven low ranked cultivars in low order were Pioneer brand 5929> Maxidor> Dekalb brand 167> Pierce> Blazer> Raidor> Pioneer brand 532. Seven high ranked cultivars from 32 alfalfa cultivars on the dry matter yield in high order were Pike>LS-1920>Challenger>Salute>Diamond>Decathlon>Pioneer brand 581, and seven low ranked cultivars in low order were Maxidor>Pioneer brand 5929>Pioneer brand 532>Florida 77> Pierce> Magnum> Blazer. Dry matter yield per cultivar was also greater when alfalfa cultivar was appeared higher plant height compared with those which were lower plant height. Leading cultivars for plant growth and yield under the Korean environmental condition were Pike, LS-1920, Challenger, Salute, Diamond among the 32 alfalfa cultivars. All those cultivars except Challenger cultivar are Semi-dormant which can be well grown under moderate temperatures.

• Journal of Food and Nutrition Research
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• v.9 no.7
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• pp.350-356
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• 2021

This study was conducted in Cheonan of central region in South Korea to identify alfalfa cultivars with superior adaptability to the local environment. To evaluate the growth characteristics, productivity, and feed value of 26 alfalfa cultivars, field experiments were conducted with a randomized block design (three replicates) for three years. Among the 26 alfalfa cultivars, "Natsuwakaba" showed the highest dry matter yield (DMY, 37,083 kg/ha), with a significantly higher three-year average than that of other cultivars. Furthermore, the three-year-average DMYs of "Alfalfa short" (31,044 kg/ha) and "Radar II Brand" (31,163 kg/ha) were significantly higher than those of other cultivars. In addition, differences among the feed values of the alfalfa cultivars were relatively less significant than the differences among their productivity, as the feed value was less influenced by the cultivation conditions and cultivars. Although "Jin Huang Hou" and "Certified organic" exhibited the highest feed values when cultivated in central region in South Korea, "Natsuwakaba" outperformed all cultivars in both productivity and feed value. The acid and neutral detergent fiber (ADF and NDF, respectively) contents of "Jin Huang Hou" (38.9% and 47.26%, respectively) were significantly lower than those of other cultivars. In contrast, the ADF and NDF contents of "Burgaltai" (46.52% and 55.56%, respectively) implied poor feed value upon cultivation in South Korea. The crude protein (CP) content in the alfalfa cultivars ranged from 14.95% to 19.44% during early flowering, and the highest CP content was observed for "Certified organic." The in-vitro digestibility of alfalfa was approximately 70% for all cultivars during early flowering, indicating good digestibility of most of the cultivars.

• Journal of The Korean Society of Grassland and Forage Science
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• v.20 no.1
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• pp.61-66
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• 2000

An experiment was conducted to evaluate the effects of seed coating on germination and early growth of tall fescue (Festuca arundinacea Schr.), orchardgrass (Dactylis glomerata L.), and alfalfa (Medicago sativa L.) over sown on unploughed hilly and forested areas. Establishment and early growth of coated tall fescue and orchardgrass on unploughed hilly area were not significantly influenced by seed coating. Establishment and early growth of coated alfalfa on unploughed hilly area were higher than non-coated and showed 4.7% and 4.0 g/m2, respectively. Establishment of coated tall fescue (11.8%) on forested area were higher than noncoated (0.3%), but ealy growth of tall fescue was not significantly influences by seed coating. Establishment of over sown orchardgrass on forested area was not significantly affected by seed coating, but early growth of coated seed (18.7%) was better than that of non-coated (0.3%). Establishment of coated alfalfa on forested area were higher than those of non-coated. Results of this study indicate that the establishment and early growth of over sown tall fescue, orchardgrass, and alfalfa could be improved by seed coating.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.4
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• pp.298-302
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• 2019

Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al₃⁺) in calcium chloride (CaCl₂) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.185-190
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• 1999

Autotoxic substance(s) from alfalfa(Medicago sativa L.) plants reduces germination and growth of adjacent new alfalfa after alfalfa. The autotoxic chemical(s) in alfalfa are clearly unknown. Our objective was to improve the sensitivity of an alfalfa seedling bioassay for evaluating autotoxic leaf extracts. We determined critical extract concentrations that inhibit seed germination and seedling growth, compared two different culture media, and evaluated the effects of extract sterilization on the sensitivity of the assay, by using streptomycin and autoclaving method. An agar medium in petri plate gave better responses of germination and seedling growth to the extracts than using filter paper in the plate. On agar medium, the concentration of extract required to reach 50% inhibition of root length was 2.7 g $kg^{-1}$, and of germination and hypocotyl length were 3.8 and 9.9 g $kg^{-1}$, respectively. Leaf extracts with 100 ppm streptomycin stimulated germination significantly compared to Leaf extract alone but reduced root length of control by 43%. Root length was more sensitive to the autotoxin(s) than was germination or hypocotyl length. These results suggest that agar medium mixed with extract and sterilization by autoclaving could be improved the consistency and precision of bioassay, and that root length was the best parameter of autotoxic effect of alfalfa leaf extract.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.3
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• pp.151-156
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• 1986

There are differences in recommendations in the USA as to whether nitrogen fertilizer should be applied when establishing alfalfa (Medicago sativa L). The reason for not applying nitrogen is because some researchers found the addition of nitrogen reduced nodulation of alfalfa plants. A replicated experiment was conducted under controlled environmental conditions at the University of Nevada-Reno, Reno, Nevada, USA, to determine the effects of nitrogen application on seedling growth and nodulation of alfalfa when grown in a cool environment. A sterile sand was used in the growing media to which a complete nutrient solution minus nitrogen was applied volumetrically to each pot daily. Half of the pots received $NH_4NO_3$, at the rate of 11.2 kg/ha, at seeding and two and four weeks after planting, giving a total nitrogen application rate of 33.6 kg/ha. Rhizobia inoculant (R-12) consisted of a mixture of strains 171-15a. 1682c and 80 PI 265 of Rhizobium meliloti. Inoculant was applied to the seeds prior to planting and to the sand media at two and four weeks after seeding. Twenty seeds were planted in pots 14.0 cm in diameter and 11.5 cm deep. Seedlings were thinned after emergence to ten plants per pot. They were grown in a controlled environment chamber with a 16-hour light period. Soil temperatures at 6 cm depth ranged from $5.7^{\circ}C\;to\;21.5^{\circ}C$ and had a daily mean of $16.2^{\circ}C$ Plants were harvested at weekly intervals for seven weeks at which time root, shoot and total length, dry weight, volume and number of nodules per plant were determined. Root, shoot and total length were not affected by nitrogen fertilizer. However, application of nitrogen increased the size of the seedlings as determined by dry weight and volume when compared to plants which were not fertilized. This indicates that rhizobia did not fix enough atmospheric nitrogen to promote good growth. Nitrogen application resulted in significantly more nodules per plant. The effect of nitrogen fertilizer became more apparent as the plant became older. Results of this experiment show there are benefits from applying nitrogen at a low rate when establishing alfalfa under a cool environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.198-206
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• 1981

A field research was conducted to evaluate the effects of inoculation of Rhizobium meliloti and lime application on the early growth of alfalfa, var. Luna, in an acid soil. Alfalfa seeds were inoculated by lime-peat pelleting method with $A_3$ strain isolated from alfalfa roots. Both inoculated and noninoculated seeds were sown in acid soil (pH 5.5) with three levels of lime application (1, 3, 6 ton/ha) on mid-April. Inoculated seeds produced many effective nodules in early stage and increased nitrogen and chlorophyll contents of leaf, consequently stimulating alfalfa growth. Pseudo nodules were found in noninoculated, while they were seldom formed in inoculated. Lime application increased soil pH, plant height, root length, and shoot and root weight. Liming effect on nodulation was significant at first cut, but no longer after then. Both inoculation and liming increased the forage yield of alfalfa. Inoculation and liming of 6 ton/ha together produced the highest yield. As compared to control plot of nitrogen application, the effect of seed inoculation only could be equal to about 120 kg/ha nitrogen application. The total nitrogen contents of forage were little affected by number or weight of nodules and amounts of lime application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.309-316
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• 2001

Helianthus tuberosus has been known to inhibit the growth of weeds and other plants sharing its habitat. This study was conducted to identify the allelochemicals of Helianthus tuberosus which were extracted with water and solvents. Aqueous extracts of leaf, stem, root, tuber and tuber peel of Helianthus tuberosus except tuber did not show significant differences in phytotoxicity to alfalfa seedlings. It was considered that Helianthus tuberosus contained fewer or less potential water-soluble substances that were toxic to alfalfa. Methanol extract of leaves of Helianthus tuberosus was sequentially partitioned in increasing polarity with n-hexane, ethylacetate and n-butanol. Each extract had a yield of 148, 12, 15.7 and 9.5g, respectively. Inhibitory effects on germination of alfalfa seeds treated with four fractions were not significantly different. But the significant reductions on hypocotyl length were observed for all the solvent extracts. Among the four fractions, the ethylacetate fraction showed the most significant inhibition effect on bioassay with alfalfa. Further separation of the active ethylacetate fraction by open column chromatography led to the 25 subfractions. In bioassay of each sub-fraction with alfalfa seeds, sub-fraction No. 13 showed the most inhibitory effect on seedling growth. $^1$H NMR and gas chromatography-mass spectrometry analysis revealed that sub-fraction No. 13 was the mixture of straight-chain saturated fatty acids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.137-145
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• 2022

Aluminum (Al) is one of the major factors adversely affects crop growth and productivity in acidic soils. In this study, the effect of Al on plants in soil was investigated by comparing the protein expression profiles of alfalfa roots exposed to Al stress treatment. Two-week-old alfalfa seedlings were exposed to Al stress treatment at pH 4.0. Total protein was extracted from alfalfa root tissue and analyzed by two-dimensional gel electrophoresis combined with MALDI-TOF/TOF mass spectrometry. A total of 45 proteins differentially expressed in Al stress-treated alfalfa root tissues were identified, of which 28 were up-regulated and 17 were down-regulated. Of the differentially expressed proteins, 7 representative proteins were further confirmed for transcript accumulation by RT-PCR analysis. The identified proteins were involved in several functional categories including disease/defense (24%), energy (22%), protein destination (9%), metabolism (7%), transcription (5%), secondary metabolism (4%), and ambiguous classification (29%). The identification of key candidate genes induced by Al in alfalfa roots will be useful to elucidate the molecular mechanisms of Al stress tolerance in alfalfa plants.