• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.232-242
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• 2002

To investigate the effects of arbuscular mycorrhizal (AM) fungus (Glomus intraradices) colonization on drought-stress tolerance, leaf water potential, chlorophyll concentration, P content and carbohydrate composition were examined in perennial ryegrass (Lolium perenne L.) plants exposed to drought-stressed or well-watered conditions. Drought stress significantly decreased leaf water potential, P content and leaf growth. These drought-induced damages were moderated by mycorrhizal colonization. Drought stress decreased the concentration of soluble sugars in shoots. AM plants had a higher foliar soluble sugar than non-AM plants under drought stress condition. Drought stress depressed the accumulation of starch and fructan in shoots, but stimulated in roots. Under drought-stressed condition, starch concentration in roots was higher in non-AM plants than in AM plants. Fructan was the largest pool of carbohydrates, showing the highest initial concentration and the highest net increase for 28 days of treatment. Drought stress slightly decreased fructan concentration in shoots, but remarkably increased in roots. Under drought-stressed condition, fructan concentrations in non-AM and AM shoots at day 28 were 18.7% and 13.3% lower than the corresponding values measured at well-watered plants. However, in the roots, fructan accumulation caused by drought was lessen 13.6% by mycorrhizal colonization. The results obtained suggest that mycorrhizal colonization improves drought tolerance of the host plants by maintaining higher leaf water status and P status, and by retaining more foliar soluble sugars.

• Journal of Plant Biotechnology
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• v.38 no.3
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• pp.221-227
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• 2011

This study was carried out to determine optimal medium conditions for mass propagation by bioreactor culture of ever-bearing strawberry (Fragaria ${\times}$ ananassa D.). Two different type of nitride were that mixed $NH_4NO_3$ and $KNO_3$ or added $KNO_3$ only. And nitride concentrations were at the 4 levels of $1/2{\times}$, $1{\times}$, $2{\times}$ and $3{\times}$ that was included $NH_4NO_3$ and $KNO_3$. Sucrose content ranged at 3 levels of $10g{\cdot}L^{-1}$, $20g{\cdot}L^{-1}$ and $30g{\cdot}L^{-1}$ and medium pH were at the 3 levels of 4.6, 5.6 and 6.6. In bioreactor culture, medium that are included $NH_4NO_3$ and $KNO_3$ together in MS medium was suitable for mass propagation. Medium EC rose rapidly when the nitride concentration was increased. For that reason, plantlet growth was inhibited. Shoots of nitride $1/2{\times}$ concentration was 10.8 ea and $1/2{\times}$ concentration was suitable for shoot propagation. Fresh weight of sucrose $30g{\cdot}L^{-1}$ was 3,101 mg which was heaviest and aerial and ground part were higher than the other concentration. Shoots were increased in proportion to the increasing concentration of sucrose. In the pH condition, from pH 5.6 to 6.8 were appropriate for the optimum growth of aerial and ground part of plant. From the results, in bioreactor culture for mass propagation, MS medium was suitable $1/2{\times}$ concentration that was included $NH_4NO_3$ and $KNO_3$ together, and added $30g{\cdot}L^{-1}$ of sucrose, and then adjusted pH between 5.6 and 6.6.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.456-461
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• 2010

A study was conducted to investigate the effect of topophysis, and uniting method of rootstock and scion on rooting and subsequent growth of stenting-propagated cut rose ($Rosa$ $hybrida$ Hort.) in an effort to develop an efficient stenting propagation method for domestic rose cultivars. Four cultivars used in this study were two standard type cultivars 'Sweet Yellow' and 'Hanmaum', and two spray type cultivars 'Chelsi' and 'May'. Scions were grafted on cuttings of a rootstock $Rosa$ $indica$ 'Major'. The stenting-propagated scion-rootstock unions were planted in rockwool cubes ($50{\times}50{\times}50mm$, Delta, Grodan, Denmark) and were placed in a graft-take chamber for five days before being placed on misted greenhouse beds. The rootstock was removed of all leaves and nodes. Both the base of scions and top of stocks were simultaneously cut at a $45^{\circ}$ angle for grafting. Scions were prepared as single node cuttings, each with a five-leaflet leaf. Three positions of topophysis used were 7-9th (top), 4-6th (middle), and 1st-3rd (bottom) nodes from the stem base. Four uniting materials used were tube, tube + parafilm wrap, tube + clothespin, and clothespin. Rooting and growth were affected by the topophysis and cultivar. The best topophysis for rooting was 7-9th (top) nodes in all cultivars. Topophysis affected percent rooting, and number of roots, length of the longest root, and but not weight, shoot length and graft-take. Rooting and growth were affected by the uniting method and cultivar. Tube uniting method generally showed higher percentage graft-take, percent rooting, and number of roots than other methods. However, rootstock and scion union was not complete in this treatment. On the whole, the greatest rooting and subsequent growth of stenting-propagated plants were found in the tube + clothespin method. Except 'Sweet Yellow', rooting and growth were not adequate in the clothespin method. The results suggested that a tube + clothespin method was the most effective, and this method may be used as a substitute to save labor compared to a tube + parafilm wrap method which is currently being used in commercial nurseries.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.449-455
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• 2010

'Moulinrouge' was selected as the best regenerating cultivar among 18 different spray-type chrysanthemum cultivars bred in the Gyeongnam Flowers Breeding Research Institute. When the leaf explants from standard- and spray-type chrysanthemum 'Jinba' and 'Moulinrouge' were incubated on MS basal medium supplemented with $0.5mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA, both 'Jinba' and 'Moulinrouge' induced adventitious shoots that can be regenerated into plantlets. Based on these regeneration conditions, we developed an efficient $Agrobacterium$-mediated chrysanthemum 'Moulinrouge' transformation method by using sequential selection of shoots from low ($10mg{\cdot}L^{-1}$) to high ($30mg{\cdot}L^{-1}$) concentrations of kanamycin after co-cultivation of leaf explants with $Agrobacterium$ for 10 days and induction of shoots. All kanamycin resistant plants investigated with genomic PCR analysis carried the report gene, $AtSICKLE$, in their genome. Although expression levels of the report gene in the transgenic plants investigated with RT-PCR were relatively low because of inefficiency of CaMV 35S promoter in chrysanthemum, transgenic lines expressing $AtSICKLE$ efficiently showed leaf epinasty phenotype. We expect that our results will provide a useful method that can perform a high-throughput investigation of genes isolated and studied well in model plants for molecular breeding of chrysanthemum.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.442-448
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• 2010

The objectives of this study were to analyze mutant lines of Chinese cabbage ($Brassica$ $rapa$ ssp. $pekinensis$) using gene tagging system (plasmid rescue and inverse polymerase chain reaction) and to observe the phenotypic characteristics. Insertional mutants were derived by transferring DNA (T-DNA) of $Agrobacterium$ for functional genomics study in Chinese cabbage. The hypocotyls of Chinese cabbage 'Seoul' were used to obtain transgenic plants with $Agrobacterium$ $tumefaciens$ harboring pRCV2 vector. To tag T-DNA from the Chinese cabbage genomic DNA, plasmid rescue and inverse PCR were applied for multiple copies and single copy insertional mutants. These techniques were successfully conducted to Chinese cabbage plant with high efficiency, and as a result, T-DNA of pRCV2 vector showed distinct various integration patterns in the transgenic plant genome. The polyploidy level analysis showed the change in phenotypic characteristics of 13 mutant lines was not due to variation in somatic chromosome number. Compared with wild type, the $T_1$ progenies showed varied phenotypes, such as decreased stamen numbers, larger or smaller flowers, upright growth habit, hairless leaves, chlorosis symptoms, narrow leaves, and deeply serrated leaves. The polyploidy level analysis showed the change in phenotypic characteristics of 13 mutant lines was not due to variation in somatic chromosome number. To tag T-DNA from the Chinese cabbage genomic DNA, plasmid rescue and inverse PCR were applied for multiple copies and single copy insertional mutants. Mutants that showed distinct phenotypic difference compared to wild type with 1 copy of T-DNA by Southern blot analysis, and with 2n = 20 of chromosome number were selected. These selected mutant lines were sequenced flanking DNA, mapped genomic loci, and the genome information of the lines is being recorded in specially developed database.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.403-408
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• 2010

This study was carried out to investigate the physiological responses of $Rhododendron$ $mucronulatum$ Turcz. and $R.$ $indicum$ (L.) Sweet seedlings with 0%, 35%, 55% and 75% shading of full sunlight in polyethylene film house. The shading treatments were performed during the late growth season for each species (from Sept. 9 to Nov. 5, 2008). The shading treatment was effective in reducing the daily temperature by 0.9 to $1.7^{\circ}C$ during September and by 0.8 to $1.7^{\circ}C$ during October. Before the shading treatments, the water content of $R.$ $mucronulatum$ and $R.$ $indicum$ amounted to 68.5% and 66.3%, respectively. The water contents of two species after 75% shading treatment period decreased to 66.2% (3.4% reduction) and 65.9% (0.6% reduction), respectively. Notably, both species had a similar tendency indicating less reduction rate of water content with 75% shading. $R.$ $indicum$ showed higher photosynthetic capacity with higher level of shading, and its photosynthetic capacity reached the highest level ($9.63{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). On the other hand, shading-treated $R.$ $indicum$ showed higher intercellular $CO_2$ concentration, stomatal conductance and transpiration rate (55% shading > 35% shading > 75% shading) than non-treated ones. In addition, non-treated seedlings showed higher water use efficiency than treated ones. In particular, it was found that the leaf color of $R.$ $mucronulatum$ turned equivalent to purple under full sunlight, while its leaf color kept equivalent more to green with higher level of shading, as evidenced even in naked eyes. According to comprehensive analysis using Munsell Color Chart on potential leaf color variations of $R.$ $mucronulatum$ depending on the level of shading, it was found that relatively many leaf colors under full sunlight were equivalent to R (red) and Y (yellow) chart, while relatively many leaf colors with higher level of shading were equivalent to G (green) and Y chart, where the latter still showed green color.

• Journal of Animal Environmental Science
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• v.18 no.sup
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• pp.13-20
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• 2012

This research investigated the effect of $SCOD_{Mn}$ concentrations and pH adjustment at the stage before land application, namely 2nd-aeration treatment stage of liquid fertilizer in the liquid fertilizer treatment process of swine manure on the physicochemical compositions of 2nd-aeration treated liquid fertilizer. The liquid fertilizer used in this research is the alkaline fermented liquid fertilizer of swine manure more than pH 9.0 through aeration treatment (Alkaline fermentation treatment group). About the alkaline liquid fertilizer, phosphate neutralization treatment was conducted with phosphoric acid and it was a phosphate neutralization treatment group. In 2nd-aeration treatment of liquid fertilizer for 30 days, each group was divided into alkaline treatment groups (T-1, T-2, and T-3) and phosphate neutralization treatment groups (T-4, T-5, and T-6) according to early $SCOD_{Mn}$ concentrations. The research results are as follows. 1. As for $SCOD_{Mn}$ reduction rate, the average 29.9% in alkaline treatment groups and the average 36.9% in phosphate neutralization treatment groups were shown and so the relatively high reduction rate was shown in phosphate neutralization treatment groups. 2. After finishing the experiment, the group of the lowest $SCOD_{Mn}$ concentrations was the phosphate neutralization treatment group, T-6 with the lowest inflow concentrations. In case the final goal level of 2nd-aeration treated liquid fertilizer is assumed as concentrations less than $SCOD_{Mn}$ 3,000 ppm, it would be desired that inflow concentrations of 2nd-aeration treatment groups are adjusted less than $SCOD_{Mn}$ 5,500 ppm. 3. As for the persistence rate of nitrogen, the average 29.3% in alkaline treatment groups and the average 38.9% in phosphate neutralization treatment groups were shown and so phosphate neutralization treatment groups showed the relatively low loss rate of nitrogen, meanwhile, in the case of T-P, phosphate neutralization treatment groups maintained high concentrations (average 1,473 ppm). 4. In the event of 2nd-aeration treatment of liquid fertilizer, "alkaline fermentation treatment" condition in 'low phosphate-low nitrogen' type and "phosphate neutralization treatment" condition in 'high phosphate-high nitrogen' type are expected to be favorable.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.227-236
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• 2010

This study was conducted to develop an measuring system and method for fermentation degree of liquid swine manure by visible ray. The constituent changes of liquid swine manure were examined. pH gradually increased with time, but EC gradually decreased. Malodor strength decreased gradually with aeration treatment with time. Control needed more time to decrease malodor strength than aeration treatment. In aeration treatment, there was no germination of seeds (radish, chinese cabbage) up to 6 weeks and germination rate at 15th week was over 50%. However, in control, there was no germination up to end of experiment. Circular chromatography method showed that there was change after 10th week in aeration treatment but there was no change up to end of experiment in control. As a result, the fermentation degree of liquid swine manure would have relations among pH, EC, germination rate, malodor concentration, and reaction of circular chromatography. The simple analytical instrument for liquid swine manure consisted of a tungsten halogen and deuterium lamp for light source, a sample holder, a quartz cell, spectrometer for spectrum analyzer, a malodour measuring device, a software, etc. Results showed that the simple analytical instrument that was developed can approximately predict the fermentation degree of liquid swine manure by visible ray. Generally, the experiment proved that the simple analytical instrument was reliable, feasible and practical for analyzing the fermentation degree of liquid swine manure.

• Journal of Animal Environmental Science
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• v.16 no.3
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• pp.237-244
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• 2010

Using a vertical composting system in layer farms, the composting process was characterized in terms of temperature variation, change of moisture contents, fertilizer ingredient and so on. In this study, two types of layer farms were examined. The layer manure was produced as 3,300 and 116,650 kg/day for Farm A and Farm B, respectively. Also, their average moisture contents were 74.4% (Farm A) and 65.6 % (Farm B). The inside temperature of composting in Farm A was varied in the range of 50 to $70^{\circ}C$, and moisture content of it decreased from 59.5% to 20.6% at the edge of vertical composting system. While in Farm B, composting temperature was fluctuated between 50 and $65^{\circ}C$ and moisture content declined from 34.0% to 13.4% at the end of vertical composting system. The fertilizer ingredients such as T-N, $P_2O_5$ and $K_2O$ were not significantly influenced by seasonal effect. Their values were changed in the range of 0.90% to 0.47% for T-N, 0.16% to 0.42% for $P_2O_5$, and 0.22% to 0.28 for $K_2O$, respectively. Also, OM/N ratio was varied from 36.8 to 84.4.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.147-154
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• 2009

The purpose of this study was to determine the effect of re-establish the amount and major compositions of slurry from swine farms. The results obtained in this study was summarized as follow; The quantity of wastewater produced from the average volume of pig slurry was $4.64{\ell}$ /head/day and $4.68{\ell}$ in spring, $4.70{\ell}$ in summer, $4.70{\ell}$ in autumn, and $4.49{\ell}$ in winter. The average moisture content of slurry was 95.5%. And the composition of pig slurry contents of N, $P_2O_5$ and $K_2O$, were 0.27, 0.20 and 0.17% in slurry, respectively. The water pollutant concentration in slurry of swine farms, $BOD_5,\;COD_{MN}$, SS, T-N and T-P, was $21,856mg/{\ell},\;33,883mg/{\ell},\;41,253mg/{\ell},\;2,869mg/{\ell}$ and $565mg/{\ell}$, respectively.