Vendelbo Bruun (sodaback01)

s in China (Huang et al. 2017; Radisek et al. 2018). This is the first report to our knowledge of powdery mildew P. fusca on H. tuberosus in China. It could cause significant yield losses and become a threat to production of H. tuberosus .Ixeris denticulata (Houtt.) Stebb is an annual herbaceous plant in the family of Asteraceae, which is native to Europe or central Asia. This plant is widely distributed in China and is commonly used for edible and medicinal purposes. In February 2019, typical symptoms of powdery mildew were observed on 70% of I. denticulata plants on the campus of Hainan University (20° 3' 25″ N; 110° 19' 4″ E) in Haikou, Hainan Province, China. White, superficial mycelia and conidia covered the leaf surfaces of affected plants, resulting in leaf curling, discoloration and defoliation. Hyphal appressoria were nipple-shaped, and solitary. Conidiophores were straight, cylindrical, 109 to 259 × 9 to 16 µm (n = 50), and produced 3 to 5 immature conidia in chains with a crenate outline. Foot cells were cylindrical, straight or sometimes constricted at the basal septum, 30 to 62 µm long (n = 100). Conidia were ellipsoid-ovoid to doliiform, 23 to 33 × 15 to 23 µm (n = 100) with a length/width ratio of 1.1 to 1.9, with well developedrecord of P. xanthii infecting I. denticulata in China. We are concerned that the pathogen will cause severe damage and affect the yield and quality of the host, and even pose a threat to I. denticulata in the future.Watermelon (Citrullus lanatus L.) is widely cultivated and consumed in Malaysia for its nutritional value. In June 2018, nearly 40% of the 'Red Rocky' watermelon plants in experimental plots of the research farm at Faculty of Agriculture, UPM Serdang, Selangor, Malaysia had leaf spot symptoms. Leaf spots were small, ranging 5 to 30 mm, yellow to brown, and circular to irregular in shape. With ages, the leafspots gradually enlarged and coalesced. To investigate the disease, ten symptomatic leaves were collected from the experimental plots. Diseased tissues (5 x 5 mm) were excied and surface sterilized with 0.5% sodium hypochlorite (NaOCl) for 2 min, rinsed twice with sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 25 °C for 5 days. A total of ten isolates with similar colony morphologies were obtained from tissue samples. A single representative isolate "F" was further characterized by molecular analysis. All colonies were initially white in color, but later turned gray to blackts (Wang et al. 2017). N. sphaerica has been reported to cause leaf spot of date palm in Pakistan (Alam et al. 2020) and kiwifruit in China (Chen et al. 2016). To our knowledge, this is the first report of N. sphaerica causing leaf spot of watermelon in Malaysia. This new disease could reduce fruit quality since sweetness and ripening are dependent on healthy foliage. Additionally, this disease can cause premature defoliation which would also reduce watermelon productivity.Hulless Cucurbita pepo is an annual herb in the Cucurbitaceae family and is one of the main economic vegetable crops in China, and is a raw material for cosmetics and health care products. It is also called hulless pumpkin because its seeds have no seed coat, which is a rare variation of the Cucurbita. In July 2010, powdery mildew was observed on hulless Cucurbita pepo 'Tianran' in fields of Wuwei District, China(Liang et al.2010). Disease incidence when first observed was 65.67%, but increased to 100% in July 2019. Early disease symptoms appeared as circular or irregular white powdery areas on both leaf surfaces. At later infection stages, entire leaves，petioles, and stems were covered with white fungal mycelia that resulted in leaf yellowing and senescence，but not defoliation . Fungal hyphae were septate, branched and flexuous to straigh. Conidiophores were unbranched, straight and grew vertically to the mycelium. Conidiophore foot cells of the were cylindrical with slight constriction at basal sept