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Sung T.-L.,Lunghwa University of Science and Technology | Teii S.,Lunghwa University of Science and Technology | Teii S.,Tokyo City University | Liu C.-M.,Lunghwa University of Science and Technology | And 7 more authors.
Vacuum | Year: 2013

The effect of pulse voltage, polarity, duty cycle, and oxygen flow rate on ozone production is studied in a coaxial cylindrical-type dielectric barrier discharge ozonizer at atmospheric pressure. For a constant oxygen flow rate, the ozone concentration increases with increasing input voltage and is nearly proportional to the ozone production efficiency. The bipolar waveform of the applied voltage results in higher ozone concentration and production efficiency than the unipolar one (positive or negative) regardless of duty cycle. A higher duty cycle increases the ozone concentration slightly for the unipolar voltage, while it affects little the ozone production efficiency for either voltage polarity. For constant pulse polarity and duty cycle, the ozone concentration decreases with increasing oxygen flow rate, however, the maximum ozone production efficiency for each flow rate shows only a minor difference for the change in flow rate. The results confirm that the ozone production efficiency depends more on the pulse power characteristics and less on the oxygen flow rate. © 2012 Elsevier Ltd. All rights reserved.


Lin K.-H.,Chinese Culture University | Huang M.-Y.,Academia Sinica, Taiwan | Huang W.-D.,National Taiwan University | Hsu M.-H.,National Taiwan University | And 3 more authors.
Scientia Horticulturae | Year: 2013

Previous studies demonstrated that the combination of red (R) and blue (B) LED light was an effective light source for plant growth and development, and the light spectra, intensities, and durations can easily be controlled by growers in artificial growing environments. Therefore, the goal of this study was to investigate the influences of three different qualities of light on plant biomass and accumulation of chlorophylls (chl), carotenoids (car), soluble proteins and sugars, and nitrates in the leaves of lettuce (Lactuca sativa L. var. capitata). The marketable sensory characteristics (crispness, sweetness, shape, and color) of fresh plants were also evaluated. Plants were hydroponically cultured with a 16-h photoperiod at 24/20°C (day/night), 75% relative humidity, 900μmolmol-1 CO2 level, and 210μmolm-2s-1 photon flux density under RB LED, RB and white (RBW) LED, and a fluorescent lamp (FL, as a control) inside growth chambers for 20 days (15 days after sowing). The shoot and root fresh and dry weights as well as the crispness, sweetness, and shape of the plants treated with RBW and FL were higher than those of plants treated with RB. The soluble sugar and nitrate contents in plants grown under RBW treatment were significantly higher and lower, respectively, compared to those under RB treatment. However, the chl, car, and soluble protein contents of lettuce leaves showed no significant differences among treatments. These results demonstrate that supplemental light quality can be strategically used to enhance the nutritional value and growth of lettuce plants grown under RBW LED lights. Precise management of the irradiance and wavelength may hold promise in maximizing the economic efficiency of plant production, quality, and nutrition potential of vegetables grown in controlled environments. © 2012 Elsevier B.V.


Lee A.-C.,National Taiwan University | Lee A.-C.,Taoyuan District Agricultural Research and Extension Station | Liao F.-S.,Taoyuan District Agricultural Research and Extension Station | Lo H.-F.,National Taiwan University
HortScience | Year: 2015

The production of lettuce, a cool-season leafy vegetable, in high tunnels the year around is a challenge for growers in subtropical regions. The aims of this research were to characterize the growth of locally grown lettuce cultivars, develop a new high-yielding cultivar by crossing romaine-type lettuce ‘Jhih Li Wo’ and Batavia type lettuce ‘Fu San’, and determine the relationships between climatic variables, temperature, and day length, and days to harvest for maximum marketable yield (DMMY) in individual cultivars in high tunnels. Nine cultivars were grown in high tunnels in the spring and winter of 2008 and summer of 2009 to evaluate growth and maximum marketable yield (MMY), the latter being defined as the aboveground fresh weight of 5 ± 0.7 cm of plant stem. Romaine lettuce ‘Jhih Li Wo’ had a higher growth rate during the initiation of plant growth in the spring of 2008. ‘Jhih Li Wo’ and Batavia lettuce ‘Fu San’ also showed higher growth rate before harvest for the MMY (GRBHD) and exhibited higher MMY and DMMY than butterhead lettuce and leaf lettuce cultivars under summer and winter regimes. However, landraces of leaf lettuce are the main lettuces grown in high tunnels in summer rather than ‘Fu San’ and ‘Jhih LiWo’ due to their needing fewer DMMY and having amore upright growth form. Among nine cultivars studied, Batavia lettuce ‘Fu San’, romaine lettuce ‘Jhih Li Wo’, and landrace ‘Bai Yeh Wo’ were found to be more adaptable to summer weather. Genotypes with superior growth and yield traits are essential for not only production but also breeding. A new cultivar, Taoyuan No.3, was developed by introducing the high growth rate trait during the initial period of plant growth from romaine lettuce ‘Jhih Li Wo’ into high-yielding Batavia lettuce ‘Fu San’. Another experiment was performed over eight successive seasons to analyze the correlation of temperature and day length on DMMY for each cultivar using multiple regression analysis from 2008 to 2009. This showed that the proposed models expressed as coefficients of multiple determinants (R2) accounted for 72%to 91% of the total variation in DMMY in each cultivar. Temperature affected DMMY the most and the relative contributions of temperature and day length to DMMY differed with cultivar. These results provide information about production practices for growers in subtropical regions to use in choosing suitable lettuce cultivars. © 2015, American Society for Horticultural Science. All rights reserved.


Wei W.-S.,National Taiwan University | Lee T.-H.,Taoyuan District Agricultural Research and Extension Station | Chung R.-S.,National Taiwan University
Taiwanese Journal of Agricultural Chemistry and Food Science | Year: 2015

Organic fertilizers have been widely used to improve soil fertility. After applying to soils, organic fertilizers which are composted from different organic precursors have varying degrees of effects on the properties of the soils. The purpose of this study was to investigate the effects of long-term continuous application of different organic fertilizers on the chemical properties and the compositions of carbon (C) and nitrogen (N) in the soil of vegetable cultivation under greenhouse condition. There were six treatments, including the applications of (1) cattle dung compost (CDComp), (2) hog dung compost (HDComp), (3) poultry dung compost (PDComp), (4) soybean meal (SBM), (5) pea residue and rice hull compost (PSRComp) and (6) the above-mentioned organic fertilizers in turn (RotAPP). All treatments were repeated four times and arranged in randomized complete block design. The experiments were proceeded for seven years, during which 37 vegetable crops were planted. The soils were then sampled for analysis. The results showed that different organic fertilizers had different effects on soil chemical properties. Long-term application of SBM resulted in greatly reduced soil pH value and priming effect on soil N degradation. The percentage of hydrochloric-acid solution unhydrolysable N and unhydrolysable C of total N and C of SBM were as high as 25% and 50%, respectively. However, after the application of SBM to the soil, the N and C in SBM were easily degraded. Accordingly, the SBM is not an adequate organic fertilizer for organic farming. The PDComp and PSRComp also resulted in reduced soil pH to very acidic condition; thus, they are also not suitable for long-term application in upland soil. The long-term application of CDComp, HDComp, PDComp, and PSRComp resulted in the accumulation of recalcitrant N and C in the soil and thus improved the soil quality. The disadvantages of continuous application of one organic fertilizer could be avoided through rotational application of different organic fertilizers, which would be an ideal strategy for organic fertilizer application.


Lin K.-H.,Chinese Culture University | Yang Y.-Y.,Chinese Culture University | Yang C.-M.,Academia Sinica, Taiwan | Huang M.-Y.,Academia Sinica, Taiwan | And 4 more authors.
BMC Research Notes | Year: 2013

Background: Herbaceous plants containing antioxidants can protect against DNA damage. The purpose of this study was to evaluate the antioxidant substances, antioxidant activity, and protection of DNA from oxidative damage in human lymphocytes induced by hydrogen peroxide (H§ssub§2§ esub§O§ssub§2§esub§). Our methods used acidic methanol and water extractions from six herbaceous plants, including Bidens alba (BA), Lycium chinense (LC), Mentha arvensis (MA), Plantago asiatica (PA), Houttuynia cordata (HC), and Centella asiatica (CA). Methods. Antioxidant compounds such as flavonol and polyphenol were analyzed. Antioxidant activity was determined by the inhibition percentage of conjugated diene formation in a linoleic acid emulsion system and by trolox-equivalent antioxidant capacity (TEAC) assay. Their antioxidative capacities for protecting human lymphocyte DNA from H§ssub§2§esub§O§ssub§2§esub§-induced strand breaks was evaluated by comet assay. Results: The studied plants were found to be rich in flavonols, especially myricetin in BA, morin in MA, quercetin in HC, and kaemperol in CA. In addition, polyphenol abounded in BA and CA. The best conjugated diene formation inhibition percentage was found in the acidic methanolic extract of PA. Regarding TEAC, the best antioxidant activity was generated from the acidic methanolic extract of HC. Water and acidic methanolic extracts of MA and HC both had better inhibition percentages of tail DNA% and tail moment as compared to the rest of the tested extracts, and significantly suppressed oxidative damage to lymphocyte DNA. Conclusion: Quercetin and morin are important for preventing peroxidation and oxidative damage to DNA, and the leaves of MA and HC extracts may have excellent potential as functional ingredients representing potential sources of natural antioxidants. © 2013 Lin et al.; licensee BioMed Central Ltd.


PubMed | Taoyuan District Agricultural Research and Extension Station and National Taiwan University
Type: Journal Article | Journal: Applied microbiology and biotechnology | Year: 2016

Biofertilizers can help improve soil quality, promote crop growth, and sustain soil health. The photosynthetic bacterium Rhodopseudomonas palustris strain PS3 (hereafter, PS3), which was isolated from Taiwanese paddy soil, can not only exert beneficial effects on plant growth but also enhance the efficiency of nutrient uptake from applied fertilizer. To produce this elite microbial isolate for practical use, product development and formulation are needed to permit the maintenance of the high quality of the inoculant during storage. The aim of this study was to select a suitable formulation that improves the survival and maintains the beneficial effects of the PS3 inoculant. Six additives (alginate, polyethylene glycol [PEG], polyvinylpyrrolidone-40 [PVP], glycerol, glucose, and horticultural oil) were used in liquid-based formulations, and their capacities for maintaining PS3 cell viability during storage in low, medium, and high temperature ranges were evaluated. Horticultural oil (0.5%) was chosen as a potential additive because it could maintain a relatively high population and conferred greater microbial vitality under various storage conditions. Furthermore, the growth-promoting effects exerted on Chinese cabbage by the formulated inoculants were significantly greater than those of the unformulated treatments. The fresh and dry weights of the shoots were significantly increased, by 10-27 and 22-40%, respectively. Horticultural oil is considered a safe, low-cost, and easy-to-process material, and this formulation would facilitate the practical use of strain PS3 in agriculture.


News Article | January 13, 2016
Site: phys.org

A new study in HortScience evaluated subtropical lettuce cultivars in high tunnels year-round. Experiments were designed to determine the feasibility of developing a new high-yield, high-growth cultivar and determine relationships between climatic variables, temperature, and day length, and the days to harvest for maximum marketable yield. Experiments involved nine cultivars commonly grown in Taiwan representing four types of lettuce: leaf, butterhead, romaine, and crisphead (Batavia). Experiments were conducted in high tunnels or growth chambers at the Taoyuan District Agricultural Research and Extension Station from 2008 to 2013. 'Fu San' (a Batavia cultivar) exhibited the highest days to harvest for maximum marketable yield (DMMY) and maximum marketable yield (MMY) among all the cultivars. 'Jhih Li Wo' (a romaine cultivar) had a higher growth rate during plant growth initiation and 'Fu San' grew more slowly than other cultivars during their entire spring growth. Results showed the lettuce yields were significantly different among planting seasons, cultivars, and interactions for MMY, DMMY, and growth rate before harvest. "Our research suggests that Batavia lettuce 'Fu San', romaine lettuce 'Jhih Li Wo', and leaf lettuce 'Bai Yeh Wo' are the most suitable cultivars for summer production," the scientists said. The scientists also assessed the feasibility of integrating plant growth characteristics for developing a new lettuce cultivar for high-tunnel use. "Our studies provided evidence that introducing the high growth rate trait during the initial period of plant growth from romaine lettuce 'Jhih Li Wo' to the high yielding Fu San cultivar was feasible for developing a new cultivar with early maturity and high yields," the study authors said. The experiments resulted in the development of a new high-yielding cultivar called 'Taoyuan No.3'. The study contains further information about production practices and suitable lettuce cultivars that can aid growers in subtropical regions. "Since the DMMY in all cultivars studied was more sensitive to temperature swings, there is a high priority for breeding high temperature-tolerant cultivars with late bolting characteristics to mitigate the effects of global warming and climate changes," the authors said. Explore further: Producing strawberries in high-pH soil at high elevations


Kuo Y.-T.,National Cheng Kung University | Hsu H.-L.,National Cheng Kung University | Yeh C.-H.,Taoyuan District Agricultural Research and Extension Station | Chang S.-B.,National Cheng Kung University
Molecular Cytogenetics | Year: 2016

Background: Preparation of good chromosome spreads without cytoplasmic contamination is the crucial step in cytogenetic mapping. To date, cytogenetic research in the Orchidaceae family has been carried out solely on mitotic metaphase chromosomes. Well-spread meiotic pachytene chromosomes can provide higher resolution and fine detail for analysis of chromosomal structure and are also beneficial for chromosomal FISH (fluorescence in situ hybridization) mapping. However, an adequate method for the preparation of meiotic pachytene chromosomes in orchid species has not yet been reported. Results: Two Taiwanese native Phalaenopsis species were selected to test the modified drop method for preparation of meiotic pachytene chromosomes from pollinia. In this modified method, pollinia were ground and treated with an enzyme mixture to completely remove cell walls. Protoplasts were resuspended in ethanol/glacial acetic acid and dropped onto a wet inclined slide of 30° from a height of 0.5 m. The sample was then flowed down the inclined plane to spread the chromosomes. Hundreds of pachytene chromosomes with little to no cytoplasmic contamination were well spread on each slide. We also showed that the resolution of 45S rDNA-containing chromosomes at the pachytene stage was up to 20 times higher than that at metaphase. Slides prepared following this modified drop method were amenable to FISH mapping of both 45S and 5S rDNA on pachytene chromosomes and, after FISH, the chromosomal structure remained intact for further analysis. Conclusion: This modified drop method is suitable for pachytene spreads from pollinia of Phalaenopsis orchids. The large number and high-resolution pachytene spreads, with little or no cytoplasmic contamination, prepared by the modified drop method could be used for FISH mapping of DNA fragments to accelerate the integration of cytogenetic and molecular research in Phalaenopsis orchids. © 2016 The Author(s).


PubMed | National Cheng Kung University and Taoyuan District Agricultural Research and Extension Station
Type: | Journal: Molecular cytogenetics | Year: 2016

Preparation of good chromosome spreads without cytoplasmic contamination is the crucial step in cytogenetic mapping. To date, cytogenetic research in the Orchidaceae family has been carried out solely on mitotic metaphase chromosomes. Well-spread meiotic pachytene chromosomes can provide higher resolution and fine detail for analysis of chromosomal structure and are also beneficial for chromosomal FISH (fluorescence in situ hybridization) mapping. However, an adequate method for the preparation of meiotic pachytene chromosomes in orchid species has not yet been reported.Two Taiwanese native Phalaenopsis species were selected to test the modified drop method for preparation of meiotic pachytene chromosomes from pollinia. In this modified method, pollinia were ground and treated with an enzyme mixture to completely remove cell walls. Protoplasts were resuspended in ethanol/glacial acetic acid and dropped onto a wet inclined slide of 30 from a height of 0.5m. The sample was then flowed down the inclined plane to spread the chromosomes. Hundreds of pachytene chromosomes with little to no cytoplasmic contamination were well spread on each slide. We also showed that the resolution of 45S rDNA-containing chromosomes at the pachytene stage was up to 20 times higher than that at metaphase. Slides prepared following this modified drop method were amenable to FISH mapping of both 45S and 5S rDNA on pachytene chromosomes and, after FISH, the chromosomal structure remained intact for further analysis.This modified drop method is suitable for pachytene spreads from pollinia of Phalaenopsis orchids. The large number and high-resolution pachytene spreads, with little or no cytoplasmic contamination, prepared by the modified drop method could be used for FISH mapping of DNA fragments to accelerate the integration of cytogenetic and molecular research in Phalaenopsis orchids.


Lee S.-J.,Taoyuan District Agricultural Research and Extension Station | Liao F.-S.,Taoyuan District Agricultural Research and Extension Station | Cheng S.-H.,Taoyuan District Agricultural Research and Extension Station
Acta Horticulturae | Year: 2010

In order to overcome the low percentage of seed germination in hybridization within and between species in the genus Calanthe, intraspecific crosses (sib crosses) of C. triplicata and C. masuca and interspecific crosses of C. triplicata × C. masuca, and its reciprocal were made. Seeds at different capsule maturity stages were harvested and cultured on Hyponex #1-based media with different additives. In intraspecific crosses, the highest percentage of seed germination in C. triplicata was 25.7% for seeds from capsules harvested on 188 days after pollination and cultured on basal medium, while that in C. masuca was 28.5% for seeds from capsules harvested 91 days after pollination and cultured on basal medium + 1 mg/L kinetin. In interspecific crosses, the highest seed germination percentage was 9.3 and 10.9 for seeds from capsules harvested at 151 and 94 days after pollination and cultured on basal medium + 2 g/L peptone in C. triplicata × C. masuca and its reciprocal, respectively.

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