Publications by authors named "Yani Zeng"

2 Publications

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First report of powdery mildew of crape jasmine () caused by in China.

Plant Dis 2020 Oct 13. Epub 2020 Oct 13.

Shenzhen Polytechnic, 47891, Shenzhen, Guangdong, China;

Crape jasmine (Tabernaemontana divaricata) is a popular flowering shrub widely grown in southern China. Its leaves and roots are used in Chinese traditional medicine. In December, 2019, powdery mildew symptoms were observed on five crape jasmine shrubs on the campus of Shenzhen Polytechnic (22°35'N; 113°56'E), in Guangdong province. Approximately 45% of leaves were infected. Symptoms initially appeared as circular to irregular white patches on the leaf petiole, and subsequently coalesced to develop into abundant hyphal growth on both sides of the leaves, which soon wilted. Hyphae were septate, branched, with simple kidney-shaped to moderately lobed appressoria. Conidia formed singly, ellipsoid-ovoid to subcylindrical, 27-37 × 14-20 μm (mean 32±2.5 × 17±1.6 μm), with a length/width ratio varying from 1.3 to 2.4. Conidiophores were erect, unbranched, consisted of two cells, 60 to 84 μm long (mean 73±4 μm), and with straight to severely kinked cylindrical foot-cells at the base, 29-35 × 3-7 μm (mean 32±3 × 6±2 μm). Chasmothecia were not observed on sampled plants. These morphological characteristics were typical to the conidial stage of the genus Erysiphe (Braun and Cook, 2012). For molecular identification, genomic DNA was extracted from conidia washed from infected leaves and using Fungal DNA Kit (Omega Bio-tek Inc., Guangzhou, China). Semi-nested PCR amplification of the internal transcribed spacer (ITS) region of rDNA was conducted by using primer sets P3 (Kusaba et al., 1995)/ITS5 and ITS5/ITS4 (White et al., 1990) for the first and second reactions, respectively. BLASTn analysis of the obtained 719 bp sequence (GenBank Accession No. MT802112) showed 99.7% identity with those of E. elevata (KY660910, MH985631, MK253282). On the basis of morphological and molecular analyses, the fungus was identified as Erysiphe elevata. To confirm pathogenicity, infected leaves were gently pressed onto healthy leaves of three healthy plants in separate pots, and three noninoculated plants were used as controls. All plants were maintained in a greenhouse at 25 ℃, and relative humidity of 50 to 65%. After 11 days, similar disease symptoms were observed on the inoculated plants while no symptoms developed on control plants. The fungus observed on the inoculated shrubs was identical morphologically to that o the original infected leaves. E. elevata is a common powdery mildew species infecting Catalpa spp. (Cook et al., 2006), Plumeria rubra (Wu et al., 2019; Yeh et al., 2019) and Eucalyptus camaldulensis (Meeboon and Takamatsu, 2017). However, no powdery mildew were found on P. rubra nearby. To our knowledge, this is the first report of this fungus infecting T. divaricata.
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October 2020

Comparison of different combined treatment processes to address the source water with high concentration of natural organic matter during snowmelt period.

J Environ Sci (China) 2015 Jan 13;27:51-8. Epub 2014 Nov 13.

School of Environment, Tsinghua University, Beijing 100084, China. Electronic address:

The source water in one forest region of the Northeast China had very high natural organic matter (NOM) concentration and heavy color during snowmelt period. The efficiency of five combined treatment processes was compared to address the high concentration of NOM and the mechanisms were also analyzed. Conventional treatment can hardly remove dissolved organic carbon (DOC) in the source water. KMnO4 pre-oxidization could improve the DOC removal to 22.0%. Post activated carbon adsorption improved the DOC removal of conventional treatment to 28.8%. The non-sufficient NOM removal could be attributed to the dominance of large molecular weight organic matters in raw water, which cannot be adsorbed by the micropore upon activated carbon. O3+activated carbon treatment are another available technology for eliminating the color and UV254 in water. However, its performance of DOC removal was only 36.4%, which could not satisfy the requirement for organic matter. The limited ozone dosage is not sufficient to mineralize the high concentration of NOM. Magnetic ion-exchange resin combined with conventional treatment could remove 96.2% of color, 96.0% of UV254 and 87.1% of DOC, enabling effluents to meet the drinking water quality standard. The high removal efficiency could be explained by the negative charge on the surface of NOM which benefits the static adsorption of NOM on the anion exchange resin. The results indicated that magnetic ion-exchange resin combined with conventional treatment is the best available technology to remove high concentration of NOM.
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January 2015