During autumn 2014, in a commercial nursery in Liancheng, Fujian, China, 2 to 3-year-old plants of V. corymbosum showed symptoms of sudden collapse, leaf discoloration, and severe wilt associated with root and basal stem rot. Phytophthora isolates isolated from symptomatic roots and stem identified as Phytophthora cinnamomi on the basis of morphological characteristics and molecular analysis. To our knowledge, this is the first report of P.cinnamomi causing root and stem rot of V. corymbosum in China. Control methods such as fungicides application are needed to reduce this disease.

Round leaf spot, caused by Mycocentrospora acerina, is one of the most destructive diseases in Sanqi (Panax notoginseng) plantations in China. Accurate and timely detection of M. acerina is critical for developing effective integrated disease management strategies. Therefore, we developed a loop-mediated isothermal amplification (LAMP) assay for detection of M. acerina with primers targeting the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (nrDNA). The LAMP reaction products were visually assessed using SYBR Green I and agarose gel electrophoresis. The ideal reaction temperature and time of LAMP assay were optimized to 64.5 °C and 45 min, respectively. The specificity of the developed LAMP assay was validated using 78 isolates belonging to 26 species, including M. acerina, Mycocentrospora species, and other plant pathogens. The LAMP assay was highly specific for M. acerina. Positive reactions were obtained only with the genomic DNA of M. acerina, and no cross-reaction was obtained with DNA extracted from other species. The detection limit of the LAMP assay for M. acerina was 10 fg genomic DNA per 25-μL reaction mixture. The LAMP assay successfully detected M. acerina in both symptomatic and latently infected leaf samples. The results indicate that the LAMP assay has the potential to be an efficient, highly specific, and sensitive method for diagnosing P. notoginseng round leaf spot disease caused by M. acerina in both the symptomatic and latent stages in the field and might be useful for disease management.

Typical symptoms of anthracnose disease were observed on D. officinale leaves in zhangzhou, Fujian, China. The causal pathogen was isolated and identified as Colletotrichum gloeosporioides. To our knowledge, this is the first report of C. gloeosporioides causing anthracnose on D. officinale Kimura et Migo in China.

3-year-old plants of Castanea mollissima were found with leaf discolouration, wilting, and stunted growth associated with severe root rot in several commercial nurseries in Jianou, Fujian, China. Five Phytophthora-like isolates were isolated from necrotic taproots and identified as Phytophthora cinnamomi on the basis of morphological characteristics and molecular analyses. Pathogenicity tests were carried out and Koch's postulates were fulfilled. This is the first report of Phytophthora root rot of C.mollissima caused by P. cinnamomi in China.

Acidovorax citrulli (Ac) is an important pathogenic bacterium causing bacterial fruit blotch (BFB) in Cucurbitaceae plants and is an important quarantine pest in China. This study was conducted to establish a rapid, convenient, and accurate visual method for detecting A. citrulli. A. citrulli-specific primers and a prober were designed based on the conserved region of the YD-repeat protein gene. Loop-mediated isothermal amplification combined with lateral flow dipstick (LAMP-LFD) was used to establish an assay for the rapid visual detection of A. citrulli by optimizing the reaction temperature and time. The specificity, sensitivity, and performance of the optimized LAMP-LFD assay were evaluated using the genomic DNA of the tested isolates, A. citrulli pure culture, infested seeds, commercial seeds, and leaf samples. The optimal assay temperature and time were 64 °C and 60 min, respectively. The assay specifically detected A. citrulli, and no cross-reactions were observed with the genomic DNA of other closely related species. The detection sensitivity of the LAMP-LFD for detecting pure genomic DNA, the bacterial suspension, bacterial amount on seeds (colony-forming units (CFU)·g⁻¹), and infection rate of seeds (%) were 1 fg·μL⁻¹, 8 CFU·mL⁻¹, 5 CFU·g⁻¹, and 0.05% infestation per reaction, respectively. The positive detection rate of the LAMP-LFD assay was 20–100% in seed samples (n = 1000 seeds) with 0.05–0.1% infestation. The LAMP-LFD assay rapidly and accurately detected A. citrulli in seeds and leaf tissues carrying pathogens. This assay thus offers the advantages of easy operation, rapidity, high specificity and sensitivity, low cost (no need for complex and expensive precision instruments), visualization of detection results, good stability, and strong applicability, which can be used for epidemiological studies and disease management.

During July of 2015, 2-year-old plants of Salix babylonica exhibited leaf discoloration, wilting, stunted growth, and basal stem and root rot with soft water-soaked to dark lesions were found in several commercial nurseries in Quanzhou, Fujian, China. Phytophthora isolates were identified as Phytophthora palmivara on the basis of morphological characteristics and molecular analysis. To our knowledge, this is the first report of P. palmivora causing stem and root rot of S. babylonica in China, such information would be helpful for growers to develop management strategies for control this new disease.