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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).

Kung T.-L.,National Taiwan University | Kung T.-L.,Taoyuan District Agricultural Research and Extension Station | Lin K.-H.,Chinese Culture University | Lin S.-F.,National Taipei University
Plant Genetic Resources: Characterisation and Utilisation | Year: 2015

There are three native varieties of edible yams (Dioscorea japonica Thunb.) in Taiwan, but germplasm has been collected from only a few. To assess the genetic diversity of 99 accessions collected from four geographically diverse regions, inter-simple sequence repeat (ISSR) DNA markers were analysed, and 90.2% of the polymorphic markers in these accessions were found. Genetic similarity among accessions ranged from 30.8 to 74.4%, averaging 48.4%. Cluster analyses revealed four main clusters plus one outlier (Dioscorea alata L.). The varieties oldhamii and pseudojaponica were separated into different clusters and var. japonica was grouped with both varieties. Since var. japonica was found to be genetically similar to var. oldhamii and var. pseudojaponica, we suggest that var. japonica is a hybrid or intermediate variety between the two varieties. Molecular analysis of variance results indicated that variation within counties (95.94%) was predominantly greater than variation among counties (3.63%) and among regions (0.43%). Overall, gene flow (N m= 0.970) estimated from genetic differentiation (G st= 0.340) suggests that gene flow among regions is relatively high. The highest genetic diversity (H= 0.191) and Shannon's index (I= 0.312), and a high gene flow (N m= 3.926) of germplasm in the northern region suggest that this region is a possible centre of dispersal and domestication of yams in Taiwan. This study provided valuable information for germplasm collection and genetic improvement. Copyright © NIAB 2015

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 | 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.

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

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