First Report of Paraphoma chrysanthemicola Causing Crown and Leaf Rot of Atractylodes lancea in China

Atractylodes lancea is an important traditional Chinese medicinal plant whose rhizome is used for treating complaints such as rheumatic diseases, digestive disorders, night blindness and influenza. Jiangsu Province is the optimal cultivation location for high-quality A. lancea rhizome. Since June 2019, symptoms of crown rot and leaf rot were observed in about 10-20% of the A. lancea in a plantation (31° 36' 1" N, 119° 6' 40" W) in Lishui, Jiangsu, China. Lesions occurred on the stem near the soil line and on the leaves (Fig. 1A). Disease incidence reached approximately 80-90% by September, 2021 (Fig. 1B) and resulted in severe loss of rhizome and seed yields. For pathogen isolation, ten samples of symptomatic stem segments and ten diseased leaves were collected, surface-sterilized using 5% NaClO solution, rinsed with sterile water, cut into 0.5-2 cm segments, and plated to potato dextrose agar (PDA), and then incubated at 30°C in darkness. Pure cultures of four isolates showing morphological characteristics of Paraphoma spp. were obtained, identified as a single P. chrysanthemicola strain, and named LSL3f2. Newly formed colonies initially consisted of white mycelia; the five-day-old colonies developed a layer of whitish grey mycelia with a grey underside. 20-day-old colonies had white mycelium along the margin and with a faint yellow inner circular part with irregular radial furrows, and the reverse side looking caramel and russet (Fig. 1C). Pycnidia were subglobose (diameter: 5 to 15 μm; Fig. 1D). Unicellular, bicellular or strings of globose or subglobose chlamydospores developed from hyphal cells (Fig. 1E and 1F). The internal transcribed spacer (ITS) region and large subulin-28S of LSL3f2 were cloned using primers ITS1/ITS4 and LR0R/LR7 (Aveskamp et al. 2010, Li et al. 2013), and deposited in GenBank (OK559658 and OK598973, respectively). BLASTn search and phylogenetic analysis showed the highest identity between LSL3f2 and P. chrysanthemicola sequences (Fig. 1G) and confirmed LSL3f2 as P. chrysanthemicola. Koch’s postulates were completed using one-month-old vegetatively propagated A. lancea plantlets growing on autoclaved vermiculite/peat mixture at 26°C with a light/dark cycle of 12/12 hours. Each plantlet was inoculated with 5 ml of conidial suspension in water (1 × 108 cfu/ml) by applying to soil close to the plantlet, with sterile water used as a mock control (n = 10). By 20 days post-inoculation, inoculated plantlets showed a range of disease symptoms consistent to those observed in infested fields (Fig. 1H). Pathogenicity was additionally confirmed using detached leaves inoculated with a colonized agar plug of LSL3f2 or an uninoculated control comparison (diameter = 5 mm) and incubated at 26℃ in the dark. Five to seven days post-inoculation, detached leaves showed leaf rot symptoms including lesions, yellowing and withering consistent with those in infested fields, while control leaves remained healthy (n = 10, Fig. 1I). The pathogen was reisolated from the diseased plantlets and detached leaves, in both cases demonstrating the micromorphological characteristics of LSL3f2. P. chrysanthemicola has been reported to cause leaf and crown rot on other plants such as Tanacetum cinerariifolium (Moslemi et al. 2018), and leaf spot on A. japonicain (Ge et al. 2016). However, this is the first report of P. chrysanthemicola causing crown and leaf rot on A. lancea in China.

IDENTIFICATION OF CHILLI PLANTS PLANTING ORGANISMS IN TEKO VILLAGE, LOMBOK TIMUR

The main objective of this research is to identify and introduce various types of pests to farmers in Teko Village, Pringgebaya District. The method used is a survey method with a data collection approach in the form of direct observation on the expanse of chili plants and questionnaires as a guide for interviews with respondent farmers. Identification of pests on chili plants in Teko Village, namely: yellow virus, anthracnose fruit rot, fruit and leaf rot, whitefly, weeds (puzzle grass, spinach, and grass weeds).

Пораженность листвы древесных насаждений города Кишинева комплексом гнилей летом 2021 года

To determine the complex of fungi that cause rot on the leaves and needles of tree species in the green spaces of Chisinau, foliage was collected in four sectors of the city. It was determined by microbio-logical methods that the complex of pathogens on the leaves differs little in different sectors. The main leaf rot fungi present on the affected leaves and needles are Alternaria sp., Aspergillus sp., Fusarium sp., Penicillium sp. For the treatment of the green spaces of Chisinau against diseases, it is advisable to carry out phytosanitary measures with biological products.

First Report of Pseudomonas oryzihabitans Causing Stem and Leaf Rot on Muskmelon in China

Muskmelon (Cucumis melo L.) is an important economic crop in China, which is planted on more than 376, 000 hectares with over 13 million tons of annual fruit production. In February 2020, a serious bacterial stem and leaf rot disease on muskmelon plants was observed in greenhouses in Liguo Town, Ledong County, Hainan Province, China (18.54° N, 108.87° E), with disease incidences being approximately 10 to 12%. Initially, soft rot symptoms appeared on petioles and stems, showing yellow bacterial ooze signs, which was different from the milky white ooze produced by Erwinia tracheiphila infection. The infected tissues of petioles, stems, and leaves eventually developed into browning and withering symptoms. To isolate and identify the causal agent, the lesion tissues were sterilized by immersion in 75% ethanol for 30 s, washed three times with sterile water, and then cut and soaked in 1 ml of distilled water for 10 min. The suspension was serially diluted and spread on Luria-Bertani agar (LB) medium. After incubation at 28°C for 24 to 36 h, the resulted bacterial colonies were tiny and were streaked on LB plate for further culture. After purification, the colonies were yellow, circular, smooth-margined, and two independent representative isolates CM-11 and CM-12 were used for further validation experiments. The electron microscope analysis showed that the pathogen was rod-shaped, with a length of 1.34 ± 0.22 μm and a width of 0.54 ± 0.06 μm (N=50), and had a single terminal flagellum. The gram staining of the two isolates was negative. Moreover, the tested strains were positive for catalase but negative for oxidase and were able to utilize D-glucose, L-arabinose, and D-mannitol. Morphological, physiological, and biochemical characteristics of both isolates were consistent with those of Pseudomonas spp. To verify the species identity of the bacterial pathogens, genomic DNA of isolates CM-11 and CM-12 was extracted and several conserved genes were amplified and sequenced, including the 16S rRNA gene with primers 27F/1492R (GenBank MW187499 and MW187500), rpoB gene with primers V4/LAPS27 (MW201910 and MW446819), and gyrB gene with primers gyrBBAUP2/APrU (MW187501 and MW187502) (Mulet et al. 2010). In the BLAST analysis, the 16S rRNA sequences showed a 99% similarity to that of Pseudomonas oryzihabitans strains TH19 (LC026009), AA21 (MG571765). The rpoB and gyrB sequences showed high similarity (> 98%) to P. oryzihabitans strains FDAARGOS_657. The phylogenetic tree analysis of rpoB and gyrB genes further verified that the two isolates CM-11 and CM-12 were most closely related to P. oryzihabitans species. Consequently, the two pathogenic isolates CM-11 and CM-12 were identified as P. oryzihabitans. Both strains of CM-11 and CM-12 were tested to accomplish Koch's postulates. Young branches of muskmelons (cultivar Yugu, 10 days after pollination) were chosen as the material for inoculation. Ten healthy detached branches were placed in 15 ml tubes by submerging the cutting wound in 5 ml of the bacterial suspension (108 CFU/ml). Ten additional branches were implemented with sterilized distilled water as a negative control. The inoculated branches were placed in a plastic box containing moistened paper at 28°C. Rotting symptoms appeared within 5 days after infection, while the control samples remained healthy. Bacteria were re-isolated from diseased tissues, and the 16S rRNA gene sequences of the isolates showed the same as those from the original pathogen. Panicle blight and grain discoloration disease caused by P. oryzihabitans on rice has been described in China (Hou et al. 2020). It’s also recently found that P. oryzihabitans caused center blackening disease on muskmelon fruit in Korea (Choi et al. 2019). This study indicated that it was a causative agent of stem and leaf rot disease during the field growth period. To the best of our knowledge, this is the first report of P. oryzihabitans causing muskmelon stem rot in China.

Morphology, Prevalence and Pathogenicity of Fungi Associated with Diseased Betel Vine (Piper betle L.) in Bangladesh

Three different fungal diseases were found prevalent namely leaf spot, leaf rot, and foot and root rot of betel vine at five different upazillas of five districts in Bangladesh. Phytophthora parasitica causing leaf rot, Colletotrichum piperis causing leaf spot, and Sclerotium rolfsii causing foot and root rot have been found. The highest incidence (41.60 per cent) and severity (21.86 per cent) of leaf rot disease were recorded at Mohanpur upazilla during the period of August. Minimum incidence (4.24 per cent) of leaf rot was recorded at Kaligong upazilla while minimum severity (2.83 per cent) was recorded at Gouronadi upazilla. The highest incidence of disease (57.44 per cent) and severity of disease (28.32 per cent) of betel vine leaf spot were recorded at same locations and same period of time as per leaf rot disease. Minimum incidence (8.32 per cent) and severity (2.72 per cent) of disease were recorded at Sitakundo upazilla during the period of May. In August at Gouranadi upazilla, highest incidence of disease (27.80 per cent) was filed in case of betel vine foot and root rot while the lowest incidence (6.00 per cent) of disease was reported at Sitakundo upazilla. Lesion sizes were varied in ranging 1.4-2.3 cm in diameter while isolates collected from Mohanpur showed highest pathogenicity caused by Phytophthora parasitica produced lesion 2.3 cm and lowest pathogenicity was recorded by Sclerotium rolfsii produced lesion 1.4 cm isolates collected from Mirpur and Mohanpur. In respects of locations and survey period, it was revealed that betel vine leaf rot and leaf spot were prevalent in Mohanpur upazilla during the month of August under Rajshahi district, and betel vine foot and root rot in Gouronadi upazilla under Barisal district.

ANALISIS PENGENDALIAN KUALITAS UNTUK MEMINIMASI PRODUK CACAT PADA BAYAM JEPANG

ABSTRAKBayam Jepang adalah komoditas unggulan yang diproduksi oleh PO. Sayur Organik Merbabu dengan tingkat penjualan tertinggi mencapai 1018 kg/bulan. Salah satu faktor yang perlu diperhatikan dalam proses produksi adalah kualitas produk, karena akan berdampak terhadap kepuasan konsumen. Akan tetapi terdapat kendala dalam proses produksi, yaitu sifat tanaman yang sangat rentan rusak dan patah jika tidak diperlakukan secara tepat. Sehingga perlu dilakukan analisis kualitas terhadap Bayam Jepang untuk menekan tingkat kerusakan. Tujuan penelitian ini adalah mengetahui jenis cacat dan faktor-faktor yang mempengaruhi kualitas Bayam Jepang. Penelitian ini dilakukan pada 16 Januari sampai 20 Februari 2020 dengan metode deskripstif kualitatif dan menggunakan alat pengendalian mutu seperti lembar periksa, histogram, peta kendali, pareto dan fishbone. Jumlah informan yang digunakan terdiri dari pemilik usaha, tenaga kerja, petani mitra dan distributor. Setelah dilakukan penelitian ditemukan lima jenis cacat yaitu daun cacat, batang patah, daun kuning, tanaman kerdil dan busuk batang atau daun. Persentase cacat yang paling tinggi adalah daun cacat. Faktor-faktor yang mempengaruhi kualitas Bayam Jepang adalah faktor manusia, metode, dan lingkungan yang didukung dengan pembuatan diagram fishbone.ABSTRACTJapanese spinach is a superior commodity produced by PO. Sayur Organik Merbabu with the highest level of sales reach 1018 kg / month. One factor that needs to be considered in production process is product quality, because it will have an impact on customer satisfaction. However, there are obstacles in the production process, namely the nature of plants that are very susceptible to damage and broken if not treated properly. So it is necessary to conduct a quality analysis of Japanese spinach on an ongoing basis to reduce the level of damage. The purpose of this study is to determine the types of defects and factors that affect the quality of Japanese spinach. This research was conducted on January 16 to February 20, 2020 with qualitative descriptive methods and using quality control tools such as check sheets, histograms, control maps, pareto and fishbone. The number of informants used consisted of business owners, workers, partner farmers and distributors. After doing the research, five types of defects were found, namely defective leaves, broken stems, yellow leaves, dwarf plants and stems or leaf rot, with the highest percentage of defects being defective leaves. While the factors that influence the quality of Japanese spinach are found, namely human factors, methods, and the environment supported by making fishbone diagrams.

Increase Resistance to Maydis Leaf Blight and Productivity of Maize in Ultisol Soils with A Combination of Organic Material and Biological Agents Biofresh

Background: Low nutrient content in ultisol soils and the result of Maydis leaf rot are a major problem in efforts to increase corn productivity in Southeast Sulawesi Province, Indonesia. The use of organic materials and biological agents is one of the solutions in increasing disease resistance and corn productivity in the environmentally friendly ultisol lands. This study aims to assess the effectiveness of the biological agent Biofresh combined with various types of organic material to increase resistance to Maydis leaf rot and maize productivity in ultisol lands. Methods: Research in April-August 2017 in Southeast Sulawesi, Indonesia. With 21 units of experiments using a random block design with 7 treatments in combination of Biofresh with organic material ‘Bokashi’. consists of: B0 = Inorganic fertilizer; B1 = Organic material of cow dung; B2 = Biofresh Biological Agent; B3 = Biofresh biological agent combined with cow dung organic matter; B4 = Biofresh biological agent combination with bokashi cow dung and straws; B5 = Biofresh combination of biological agents with bokashi cow dung and soybean Sitter; B6 = Biofresh Biological agent combination with all Cow, straw and soybean bokashi. Result: The results showed that the combination of Biofresh with organic material in the form of bokashi at a dose of 5 tons ha-1 was very effective in increasing the durability and productivity of corn plants in ultisol land. The combination of Biofresh biological agents with bokashi containing cow’s feses, straw, and soy litter can reduce Maydis leaf blight leaf blight disease by 47.36% and increase production by 53.54%. Disease suppression index is positively correlated with maize crop productivity in Ultisol land.