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Wu Y.-C.,National Taiwan University | Wu Y.-C.,Taichung District Agricultural Research and Extension Station | Chang S.-J.,Miaoli District Agricultural Research and Extension Station | Lur H.-S.,National Taiwan University
Plant Production Science | Year: 2016

Typical japonica type rice is sensitive to high temperature. Pon-Lai rice is a special japonica type with adaptation to the subtropical climate in Taiwan. Facing climate change, rising temperatures would damage the yield and quality of rice production. This research was conducted using Pon-Lai rice in the field of a subtropical climate. We conducted 2 experiments, including a year-round experiment and collection of samples from different districts for building different temperature conditions. We analyzed the correlation between rising temperature and rice yield or quality. In our results, the critical period of temperature effect is 0–15 days after heading (H15). The threshold of high temperature damage in yield and appearance quality was 25–27 °C. Grain weight decreased about 2–6%, while the temperature of H15 was raised 1 °C above the thresholds. Perfect grain ratio and chalky grain ratio decreased and increased, respectively, while the temperature of H15 was raised above the thresholds. However, the high temperature in H15 affected the physicochemical characteristics. In addition, we found positive correlation between grain length to width ratio and perfect grain ratio. Grain length to width ratio could be an index of temperature effects for grain quality. In our study, when the temperature was below 30 °C, a rising temperature of H15 could damage rice yield and appearance quality, and change grain shape. Our results could provide reference for dealing with the warming future in other temperate rice-cultivated countries. © 2016 The Author(s).

Chen W.-L.,Taichung District Agricultural Research and Extension Station | Chen W.-L.,National Taiwan University | Yang W.-J.,National Taiwan University | Lo H.-F.,National Taiwan University | Yeh D.-M.,National Taiwan University
Scientia Horticulturae | Year: 2014

Leafy radish (Raphanus sativus L. var. oleiformis Pers.), a temperate crop, is usually heat-sensitive. Line 9911-9 is a heat-tolerant line bred for summer vegetables in Taiwan. Understanding the heat tolerance mechanism of Line 9911-9 may facilitate future breeding programs. We conducted a comparative study on growing plants of heat-tolerant Line 9911-9, moderately tolerant Line 9611, and heat-sensitive 'Taichung No. 1' at 40/35°C and 25/20°C to elucidate the heat tolerance mechanism of leafy radish. After 28-day of acclimation, the maintenance of net photosynthetic rate (Pn) and chlorophyll fluorescence (Fv/Fm) accompanying a double increase of stomatal conductance (gs) and transpiration rate (E) in Line 9911-9 revealed that the heat-tolerant line had adjusted physiologically to be more efficient in heat dispersing. Morphologically, Line 9911-9 developed more xylem vessels, an enlarged stomatal aperture by 5-fold, and an increased stomatal opening to 93%, which contributed 6-fold increase in the occupancy of total stomata aperture on leaf without altering stomata density under high temperature stress. Furthermore, the occupancy was correlated with gs and E with a coefficient of 0.87 and 0.98, respectively, confirming that stomatal factors play a crucial role in heat tolerance in leafy radish. Regarding the heat shock response, Line 9911-9 could have sustained over 9 days at 40/35°C, whereas Line 9611 was maintained over 3 days, with 'Taichung No. 1' for only 1 day. Line 9911-9 was able to maintain its cellular membrane stability by inducing the activities of superoxide dismutase (SOD) and catalase (CAT) to scavenge reactive oxygen species (ROS) within the first 24h and detoxify ROS unbalance under high temperature stress. These results indicated that Line 9911-9 was able to lower the non-stomatal limitation effect on Pn. A high correlation (R2=0.89) between cotyledon relative injury at 50°C for 30min in 21 leafy radish accessions and their yield reduction ratio under high temperature stress suggests that the CMT of cotyledon may be used as a reliable index for selecting heat-tolerant leafy radish. © 2014 Elsevier B.V.

Yen J.-H.,National Taiwan University | Wang Y.-S.,National Taiwan University | Hsu W.-S.,National Taiwan University | Chen W.-C.,Taichung District Agricultural Research and Extension Station
Journal of Environmental Science and Health - Part B Pesticides, Food Contaminants, and Agricultural Wastes | Year: 2013

We investigated changes in population and taxonomic distribution of cultivable bacteria and diazotrophs with butachlor application in rice paddy soils. Population changes were measured by the traditional plate-count method, and taxonomic distribution was studied by 16S rDNA sequencing, then maximum parsimony phylogenic analysis with bootstrapping (1,000 replications). The bacterial population was higher after 39 than 7 days of rice cultivation, which indicated the augmentation of soil microbes by rice root exudates. The application of butachlor increased the diazotrophic population in both upper (0-3 cm) and lower (3-15 cm) layers of soils. Especially at day 39, the population of diazotrophs was 1.8 and 1.6 times that of the control in upper and lower layer soils, respectively. We found several bacterial strains only with butachlor application; examples are strains closest to Bacillus arsenicus, B. marisflavi, B. luciferensis, B. pumilus, and Pseudomonas alvei. Among diazotrophs, three strains closely related to Streptomyces sp. or Rhrizobium sp. were found only with butachlor application. The population of cultivable bacteria and the species composition were both changed with butachlor application, which explains in part the contribution of butachlor to augmenting soil nitrogen-fixing ability. © 2013 Copyright Taylor and Francis Group, LLC.

Lee M.-J.,Chang Jung Christian University | Chen Y.,Chang Jung Christian University | Chen Y.,Taichung District Agricultural Research and Extension Station | Huang Y.-P.,Cheng Shiu University | And 6 more authors.
Journal of Cellular Biochemistry | Year: 2013

Polyamines are naturally occurring organic polycations that are ubiquitous in all organisms, and are essential for cell proliferation and differentiation. Although polyamines are involved in various cellular processes, their roles in stem cell differentiation are relatively unexplored. In this study, we found that exogenous polyamines, putrescine, spermidine, and spermine, promoted osteogenic differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs) without inducing cell death or apoptosis. Alkaline phosphatase (ALP) activity and the mRNA level of osteogenic genes, including Runx2, ALP, osteopontin, and osteocalcin, were up-regulated by exogenous polyamines. When hBMSCs were cultured at high cell density favoring adipocyte formation, exogenous polyamines resulted in down-regulation of adipogenic genes such as PPARγ, aP2, and adipsin. Extracellular matrix mineralization, a marker for osteoblast maturation, was enhanced in the presence of exogenous polyamines, while lipid accumulation, an indication of adipogenic differentiation, was attenuated. Exogenous polyamines increased the mRNA expression of polyamine-modulated factor 1 (PMF-1) and its downstream effector, spermidine/spermine N1-acetyltransferase (SSAT), while that of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis, was suppressed. These results lead to possible connections between polyamine metabolism and osteogenic differentiation pathways. To summarize, this study provides evidence for the involvement of polyamines in osteogenic differentiation of hBMSCs, and is the first to demonstrate that osteogenic and adipogenic differentiation are reciprocally regulated by exogenous polyamines. © 2013 Wiley Periodicals, Inc.

Chang C.,National Chung Hsing University | Hu W.-H.,CSIC - National Museum of Natural Sciences | Hu W.-H.,National Chung Hsing University | Chen Y.-C.,Taichung District Agricultural Research and Extension Station | And 2 more authors.
Botanical Studies | Year: 2010

The capsules of Eulophia graminea Lindl. were collected from a seashore and a city of subtropical Taiwan. The seeds from the capsules sown in vitro and germinated, hence developed into rhizomes where they either sprouted to form flower stems or developed leaf shoots with roots. The subculture rhizomes that produced a large amount of flower stems generated flowering. The plantlets with flower stems were then cultured in a medium for fruition. Some capsules formed through the autogamous mating system were harvested and their seeds were sown in vitro. A total of 4 generations were cultured over a 4 year period. There are three explanations that support the findings of the E. graminea and its strong colonization ability: the unique storage structure of the rhizome, the brief juvenile stage and the autogamous mating system.

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