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Tseng M.N.,National Taiwan University | Tseng M.N.,Kaohsiung District Agricultural Research and Extension Station | Chung P.C.,National Taiwan University | Chung P.C.,Miaoli District Agricultural Research and Extension Station | Tzean S.S.,National Taiwan University
Applied and Environmental Microbiology | Year: 2011

Entomopathogenic fungi have been used for biocontrol of insect pests for many decades. However, the efficacy of such fungi in field trials is often inconsistent, mainly due to environmental stresses, such as UV radiation, temperature extremes, and desiccation. To circumvent these hurdles, metabolic engineering of dihydroxynaphthalene (DHN) melanin biosynthetic genes (polyketide synthase, scytalone dehydratase, and 1,3,8-trihydroxynaphthalene reductase genes) cloned from Alternaria alternata were transformed into the amelanotic entomopathogenic fungus Metarhizium anisopliae via Agrobacterium-mediated transformation. Melanin expression in the transformant of M. anisopliae was verified by spectrophotometric methods, liquid chromatography/mass spectrometry (LC/MS), and confocal microscopy. The transformant, especially under stresses, showed notably enhanced antistress capacity and virulence, in terms of germination and survival rate, infectivity, and reduced median time to death (LT 50) in killing diamondback moth (Plutella xylostella) larvae compared with the wild type. The possible mechanisms in enhancing the stress tolerance and virulence, and the significance and potential for engineering melanin biosynthesis genes in other biocontrol agents and crops to improve antistress fitness are discussed. © 2011, American Society for Microbiology.

Liao Y.K.,National Chiayi University | Wu Y.H.,Miaoli District Agricultural Research and Extension Station
Botanical Studies | Year: 2011

This study describes a Platycerium bifurcatum (Cav.) C. Chr. propagation method through initiation of green globular bodies (GGBs) from juvenile leaf explants of in vitro grown sporophytes. The GGB initiation was first obtained by incubating the explants on MS medium supplemented with α-naphthalene acetic acid (NAA) and two other cytokinins, 2-isopentenyl adenine (2ip) or 6-benzylaminopruine (BA). NAA at 5.37 μM was determined a better concentration for the initiation. However, as the cytokinin concentration in the medium increased, it inhibited GGB production. Individually harvested GGBs proliferated well on a medium supplemented with 5.37 μM NAA and 2.22 μM 2ip; they displayed less sporophyte formation but a faster increase in diameter. Multiple sporophytes were subsequently regenerated by culturing GGBs on a hormone-free MS medium at the regeneration stage. Non-rooted and separated sporophytes were directly transplanted to four different types of potting media, namely sphagnum, vermiculite, peat, and a mixed medium (vermiculite:peat = 1:1). Spontaneous rooting was observed during the first 4-week acclimatization period. Even with the omission of an adventitious root induction step, the survival rate of the plants was 88% or higher. No significant difference in plant survival was detected among the different media. Using our proposed propagation procedures, it was possible to obtain an estimated production of about 170 sporophytes per initial leaf explant (proximal section; 1/2 of the leaf ≤ 2.0 cm in length) during a 32-week culturing period.

PubMed | Miaoli District Agricultural Research and Extension Station, Czech Republic Crop Research Institute and National Chung Hsing University
Type: Journal Article | Journal: Journal of economic entomology | Year: 2016

Orius strigicollis (Poppius) is an anthocorid bug with high foraging ability on thrips as well as on mites, and the bug has been considered as a potential biological control agent in Taiwan. Life table and predation studies of O. strigicollis fed on Cadra cautella (Walker) and Tetranychus urticae (Koch) eggs were conducted at 251C. Data were analyzed and compared using TWOSEX-MSChart and CONSUME-MSChart software. O. strigicollis fed on eggs of C. cautella, a substitute prey, showed significantly higher survival rate and developmental rate than individuals fed on their natural prey, T. urticae eggs. The fecundity of O. strigicollis fed on C. cautella eggs was, on average, 13.2 times higher than that of those fed on T. urticae eggs, despite of the fact that during the entire nymphal stage, the consumption rate of O. strigicollis on T. urticae eggs was ca. 9 times higher than on almond moth eggs The conversion rate (i.e., number of prey eggs needed to produce one predator egg) for this predatory bug reared on T. urticae eggs and almond moth eggs were 604.6 and 6.0, respectively, indicating that almond moth eggs served as an effective alternative prey for ensuring the predators reproduction. This is the first study pertaining to the population parameters and predation rates of O. strigicollis using the age-stage two-sex approach to describe differences between O. strigicollis populations reared on natural and alternative preys. This information may be useful in mass rearing programs and field application involving this biological control agent.

Chen C.-C.,Miaoli District Agricultural Research and Extension Station | Huang W.-D.,National Taiwan University | Yang C.-M.,Academia Sinica, Taiwan
Research Journal of Biotechnology | Year: 2016

Our objectives in this study were to investigate morphological traits and dynamics of chlorophyll (Chl) degradation intermediates (chlorophyllide, Chlide; pheophytin, Phe; pheophorbide, Pho) in leaves of rice (Oryza sativa L.) seedlings under increasing green light intensity. Seedlings of Taichung Native 1 (TCN1) were grown under equal intensities (40 μmol m-2 s-1) of red and blue light with four levels of green light intensity (0, 20, 40 and 60 μmol m-2 s-1). Light emitting diodes (LED) were used to control lighting treatments. Sheaths of rice seedling leaves elongated and leaves grew erectly under red and blue light with increasing green light intensity. These morphological traits are known as shade avoidance symptoms (SAS). Increasing green light intensity resulted in decreases in total chlorophyll, the effective quantum yield of photosystem II (ΦPSII) and Phe/Chlide ratios and increases in non-photochemical quenching (NPQ) and Chlide levels. These results indicated that green light induced SAS and mediated Chl degradation routes in rice seedlings.

Hsieh T.-Y.,National Chung Hsing University | Ku S.-M.,Academia Sinica, Taiwan | Chien C.-T.,Taiwan Forestry Research Institute | Liou Y.-T.,Miaoli District Agricultural Research and Extension Station
Botanical Studies | Year: 2011

Although kiwifruit (Actinidia) is popular worldwide, its complex morphology has resulted in long-standing confusion regarding its nomenclature, classification, and identification. In an attempt to resolve this issue, we conducted a phylogenetic analysis on 72 wild Actinidia accessions in Taiwan. We used 60 morphological characters as taxonomic traits to construct a seriated heat map that revealed A. callosa var. ephippioidea and A. rufa (sensu Flora of Taiwan, 2 nd Edition) as introgressive hybrids between A. chinensis var. setosa and A. callosa (sensu Flora of Taiwan, 2 nd Edition), as well as five significant groups of Actinida in Taiwan. Based on these results, we coded the indicator response matrix for the logistic regression models as dichotomizers and used a Bayesian discriminant model as a polychotomizer. After classifier modeling, the two classifiers were combined to identify Actinidia specimens in domestic and international herbaria. As a result, a taxonomic revision was made: A. callosa var. callosa and A. callosa var. ephippioidea were revised as A. rufa; A. rubricaulis was revised as A. callosa var. discolor; A. chinensis var. setosa was elevated to A. setosa; and A. tetramera was a misidentification of A. arguta. Of these, only A. setosa is endemic to Taiwan.

Lu M.-C.,Miaoli District Agricultural Research and Extension Station
Acta Horticulturae | Year: 2010

Pleione formosana Hayata, known as the one-foliate orchid, is a native terrestrial orchid in Taiwan. This study investigated the effect of mother bulb size on flowering and daughter bulb formation, and the application of gibberellic acid (GA) on the bulb growth in Nan-Chung village. The results showed that the bulb size was in proportion to the flowering percentage, floret number, diameter, scape number and length. However, the shelf life was not influenced by bulb size. The number and weight of daughter bulbs after harvest was in proportion to the size of mother bulbs. Different concentrations of GA 3 (0, 25, 50, 75, 125 mg/L) was applied to bulbs by spraying during growth or immersion before planting, and the daughter bulb characteristics were investigated after harvest. The results indicated that GA 3 spraying during growth significantly increased the total fresh weight, diameter and height of daughter bulbs.

Lu M.-C.,Miaoli District Agricultural Research and Extension Station
Acta Horticulturae | Year: 2010

An in vitro method was developed to regenerate plantlets from protocormderived callus of Geodorum densiflorum (Lam.) Schltr. cultured on half-strength Murashige-Skoog medium with 2,4-dichlorophenoxyacetic acid (2,4-D) at 3 to 5 mg/L and 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea (TDZ) at 0.1 to 0.5 mg/L in the dark. The proliferation rate of the pale-yellow embryogenic callus was 3.9 to 4.2 fold in mediums containing 2,4-D 3 mg/L and TDZ 0.1 to 0.5 mg/L after one month of culture in the dark. The callus was regenerated to plantlets via protocorm-like bodies (PLBs) on medium containing 0.5 mg/L TDZ after 6 months of culture, and 644 PLBs and 56 shoot buds per 0.1 g callus were obtained after 12 months of culture. The well-rooted plantlets with pseudobulbs were transferred to sphagnum-containing pots and acclimatized in a greenhouse. The embryogenic callus of the endangered orchid, Geodorum densiflorum has been established.

Wang R.-J.,Miaoli District Agricultural Research and Extension Station | Wang R.-J.,National Chung Hsing University | Hu M.-L.,National Chung Hsing University
International Journal of Food Properties | Year: 2011

This study provides a basis and principle for developing an integrated antioxidant assay of mulberry. Five genotypes (Miaoli No. 1, 73C020, 46C019, 74H3023, and 68H22024) and three maturity stages (unripe, medium ripe and fully ripe) of mulberry (Morus sp.) fruit were analyzed for their total phenolic contents (TPC), 1,1-diphenyl-2-picrylhydrazyl-scavenging (DPPH-SC) ability, ferric reducing antioxidant power (FRAP), and oxygen radical antioxidant capacity (ORAC). Significant correlations were obtained for the four assays used (r ranging from 0.390 to 0.787, all P < 0.01). Two-way ANOVA revealed that there were significant effects of genotype, maturity stage, and the interaction of genotypes and maturity stages for TPC, FRAP and ORAC, whereas only maturity stage and the interaction term were significant for DPPH-SC activity. Principal component analysis showed that Miaoli No. 1 and 74H 3023 possessed the highest antioxidant capacity, while genotype 68H22024 possessed the lowest. Principal component analysis could group and separate mulberry genotypes based on their different antioxidant activities. Overall, the present results provided basic data for choosing mulberry fruits with higher antioxidant activity for direct consumption or for production of fruit juice. Copyright © Taylor & Francis Group, LLC.

Wang R.-J.,Miaoli District Agricultural Research and Extension Station | Wang R.-J.,National Chung Hsing University | Yang C.-H.,Agricultural Chemicals and Toxic Substances Research Institute | Hu M.-L.,National Chung Hsing University
Journal of Agricultural and Food Chemistry | Year: 2010

1-Deoxynojirimycin (1-DNJ), an iminosugar rich in mulberry, has been shown to possess antimetastatic potential. The antimetastatic mechanisms of 1-DNJ in melanoma B16F10 cells were studied, as were the antimetastatic activity (cell adhesion, migration, and invasion) of 1-DNJ, matrix metalloproteinases (MMP-2 and MMP-9), tissue inhibitors of metalloproteinase (TIMP-1 and TIMP-2) mRNA, and flow cytometric analysis of cell surface in melanoma B16F10 cells. 1-DJ significantly inhibited invasion, migration, and cell-matrix adhesion and markedly decreased MMP-2 and MMP-9 activity and mRNA expression. In contrast, 1-DNJ effectively enhanced the expression of TIMP-2 mRNA. In addition, 1-DNJ significantly decreased abnormal glycosylation and/or sialylation on B16F10 melanoma cell surface but increased the levels of R-mannose. Thus, the antimetastatic effects of 1-DNJ against B16F10 melanoma cells are likely associated with its attenuated activities and expression of MMP-2/9, enhancement of the TIMP-2 mRNA expression, and alterations of the cell surface-binding motif. These results suggest that 1-DNJ may be useful as an adjuvant of antimetastatic agents such as cisplatin. © 2010 American Chemical Society.

PubMed | Miaoli District Agricultural Research and Extension Station and Chung Shan Medical University
Type: | Journal: Food chemistry | Year: 2016

Antioxidant components and properties (assayed by scavenging DPPH radicals, TEAC, reducing power, and inhibiting Cu(2+)-induced human LDL oxidation) of leaves and stems from three inbred varieties of Lycium chinense Miller, namely ML01, ML02 and ML02-TY, harvested from January to April were studied. Their flavonoid and phenolic acid compositions were also analyzed by HPLC. For each variety, the leaves and stems collected in higher temperature month had higher contents of total phenol, total flavonoid and condensed tannin. Contents of these components in the samples collected in different months were in the order: April (22.3C)>March (18.0C)>January (15.6C)>February (15.4C). Antioxidant activities of the leaves and stems for all assays also showed similar trends. The samples from different varieties collected in the same month also possessed different phenolic compositions and contents and antioxidant activities. Their antioxidant activities were significantly correlated with flavonoid and phenolic contents.

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