Rapid Detection of Colletotrichum siamense from Infected Tea Plants Using Filter-Disc DNA Extraction and Loop-Mediated Isothermal Amplification.

The pathogen Colletotrichum siamense causes tea anthracnose, resulting in economic losses to the Chinese tea industry. To effectively diagnose this pathogen in the field, we developed a loop-mediated isothermal amplification (LAMP) method using highly specific primers with a sensitivity of 1 pg/µl designed for amplifying the CAL gene, which was 10 times higher than that of conventional PCR. Additionally, to improve the method for obtaining DNA samples required for on-site diagnosis, we used the filter-disc DNA extraction method, which does not require special instruments and can be completed in a few minutes, and found that it effectively meets the requirements for the LAMP reaction. Finally, we combined LAMP with a filter-disc DNA extraction method (FDE-LAMP) to diagnose different degrees of disease in inoculated samples and 20 samples from the field. The results showed that the procedure had sufficient sensitivity for pathogen detection. Therefore, the FDE-LAMP procedure could greatly contribute to managing and preventing tea anthracnose in the field.

Preparation of flexible and UV-blocking films from lignin-containing cellulose incorporated with tea polyphenol/citric acid.

Lignin-containing bamboo cellulose, fractionated from a pilot-scale microwave liquefaction of bamboo was dissolved in tetrabutylammonium acetate/dimethyl sulfoxide (TBAA/DMSO) for the fabrication of highly flexible, transparent and UV-blocking films. Tea polyphenol (TP) or citric acid (CA) was added during the dissolving process in order to modify the film's properties. The results showed that the addition of TP obviously improved the elongation at break (triple that of the control) and UV-blocking ability of the films. Both the addition of TP and CA could increase the water contact angle of the films. The films incorporated with TP and CA were much more thermal stable than previously reported similar films. The proposed film fabrication mechanism revealed that stable hydrogen bonds formed between the lignin-cellulose matrix and TP/CA, resulting in the enhancement on the properties of the films. This present study showed that lignin-containing cellulose with the incorporation of TP/CA had great potential in the preparation of films in place of plastic.

Chemical composition, UV/vis absorptivity, and antioxidant activity of essential oils from bark and leaf of phoebe zhennan S. K. Lee & F. N. Wei.

The chemical composition of essential oils (EO) from bark and leaf of P. zhennan was identified by GC-MS. The compounds of α-calacorene, τ-cadinol, ß-eudesmol and d-cadinene were found in the essential oils from both bark and leaf. The UV-Vis spectra results indicated the EO could completely absorbed the UV light at the wavelength range of 200-370 nm, revealing that EO had great potential as additives for manufacturing UV light blocking products. The radical DPPH scavenging activity assay showed that both the bark and leaf EO possessed strong DPPH radical scavenging activity of 90.25% and 82.10% respectively, which provides an important theoretical guiding in exploiting the value of P. zhennan bark and leaf.[Formula: see text].