Emilia sonchifolia is a medical plant belonging to the family of Asteraceae, mainly used as a traditional Chinese medicine with the function of anti-inflammatory, analgesic, antibacterial and so on. During October to November 2020, the plants showing abnormal symptoms including witches'-broom, internode shortening, leaf chlorosis and leaflet were found in Hainan province, a tropical island of China. The total DNA of the plant samples were extracted using 0.10 g fresh plant leaves using CTAB method. PCR reactions were performed using primers R16mF2/R16mR1 and secAfor1/secArev3 specific for phytoplasma 16S rRNA and secA gene fragments. The target productions of the two gene fragments of phytoplasma were detected in the DNA from three symptomatic plant samples whereas not in the DNA from the symptomless plant samples. The two gene fragments of the DNA extracted from the symptomatic plant samples were all identical, with the length of 1324 bp 16S rRNA and 760 bp secA gene sequence fragments, putatively encoding 253 (secA) amino acids sequence. The phytoplasma strain was named as Emilia sonchifolia witches'-broom (EsWB) phytoplasma, EsWB-hnda strain. To our knowledge, this was the first report that Emilia sonchifolia witches'-broom disease was caused by the phytoplasma belonging to16SrII-V subgroup in Hainan island of China, with close relationship to 16SrII peanut witches'-broom group phytoplasma strains infecting the plants like peanut, Desmodium ovalifolium and cleome from the same island of China and cassava from Viet Nam.In November 2020, leaf sheath on maize (Zea mays) was detected in southeastern Jiangsu (Nantong municipality; 120.54° E, 31.58° N) in China. Physiologically mature plants, 13 weeks of cultivation (at the harvest stage), exhibited red-brown lesions in stem and leaves, and dried-up stem (Figure 1). The symptoms were observed on approximately 95% of the maize plants in a 0.8 ha maize field surrounded by old sorghum fields and the crop yield was decreased by 70-85% with respect previous years, when no disease symptoms were detected. Small pieces, approximately 0.3 cm2 in size, of symptomatic tissue were surface sterilized in 1.5% NaOCl for 1 min, and washed twice with sterile ddH2O. The pathogen was isolated (one isolate was obtained) and cultured on PDA medium, containing chloramphenicol (50 µg/mL), under darkness at 26 ºC for 3 days. Amplification of internal transcribed spacer (ITS), large subunit (LSU), actin (ACT) and β-tubulin (TUB2) genes was performed using ITS1/ITS4, LR0R/LR7, ACT512F/ACT783R and T1/Bt2bty of this pathogen. The pathogen was also reported to cause leaf spot on maize in Brazil in 2004 (Do Amaral et al. 2004); however, this is the first report of E. sorghinum causing leaf sheath and leaf spot on maize in China. Maize an important agricultural crop in China with more than 168 million tons produced in 2019. The observed yield loss and disease incidence of the isolated strain suggest that E. sorghinum may be a threat to maize production in China.In Aug 2019, approximately 10% of mung bean plants at the experimental farm of the Jiangsu Academy of Agricultural Science (32.03 N; 118.88 E) showed symptoms of stunting and wilting. Brown and water-soaked stem lesions were often observed at the base of the diseased plants. In severe cases, the plants collapsed and cumulous aerial mycelia were visible on the basal stem surface (Figure S1 A). To identify the causal agent, a total of 20 tissue fragments (5 mm long) were excised from roots and basal stems of five symptomatic plants. The fragments were surface sterilized in 2% sodium hypochlorite solution then plated on 2.5% potato dextrose agar (PDA) plates containing 10 μg/mL pimaricin, 100 μg/mL ampicillin, 10 μg/mL rifampicin, and 10 μg/mL pentachloronitrobenzene (PARP; Beckerman et al. 2017). After 3-4 days incubation at 25oC in dark, 14 colonies with white and cumulous mycelia grew from the tissue pieces (named as JS19-1 to JS19-14). JS19-1 and JS19-2 were purified by hyphal tipping, then grown on PDA medieated twice. P. aphanidermatum causes seed rot, pre- and postemergence damping-off, or stem/root rot of a wide range of industrial crops and vegetables (Liu et al, 2018). To our knowledge, this is the first report of P. aphanidermatum causing disease on mung bean in China. Since Phytophthora vignae (Sun et al, 2020) and P. myriotylum (Yan et al, 2021) have been reported causing mung bean root rot, integrated disease management should be adopted to reduce damage.Buckwheat (Fagopyrum esculentum), belonging to the Polygonaceae family, is one of the most important "functional food" crops in China. In fall 2020, buckwheat plants grown in field exhibiting stem canker symptoms were found in Tongxin county, Ningxia province, China. Symptoms included stem canker, dieback and extensive vascular discoloration. Cankers were bleached, silvery-white to dark gray, slightly sunken, oval to linear with slightly tapered tips, pycnidia formation was also observed within the cankers. Disease incidence was approximately 30% and moderate to high severity across the field. Symptomatic tissues were cut into 1-2 cm pieces, surface sterilized (75% ethanol for 30 s and 0.1% NaClO for 2 min) and washed four times with sterile distilled water, dried in sterile filter paper for 3 times, and placed on potato dextrose agar (PDA) at 25 ℃. Fluffy mycelium was visible for all isolates after 48 h of incubation. Twenty-five single isolates were hyphal-tip purified on PDA. Six representative isolates werence of this disease may represent a significant impact for buckwheat production because this crop is the major agricultural commodity in some parts of China. More studies are needed to understand the epidemiology of this disease and foster disease management programs in China.Codonopsis pilosula Franch., also known as Dangshen, is an important medicinal plant in China. It is widely cultivated for a major income of local farmers in Dingxi, Gansu Province. Its dried roots have the effects of supplementing vital energy, nourishing spleen and lung, enhancing organic immunity, helping depressurization, and improving microcirculation, etc., for humans. In June to October, 2018-2020, root rot disease was observed on C. pilosula with incidences up to 20% in the Dingxi region. We collected ten diseased and healthy plants from Dingxi (35°06'N, 104°29'E, 2206 m a.s.l.) in October 2019. The rotting root tissues were sterilized with 70% ethanol for 30 s and 3% NaOCl for 5 min and placed on potato dextrose agar (PDA) plates incubated at 25℃to isolate the pathogen (Shang et al. 2014). https://www.selleckchem.com/products/deutenzalutamide.html From the similar fungal cultures isolated after 7 days on PGA, isolate B17 was purified for morphological and molecular characterization. Its colony appeared light purple and produced long aerial hyphae. Slightly curved macroconidia (12.
Emilia sonchifolia is a medical plant belonging to the family of Asteraceae, mainly used as a traditional Chinese medicine with the function of anti-inflammatory, analgesic, antibacterial and so on. During October to November 2020, the plants showing abnormal symptoms including witches'-broom, internode shortening, leaf chlorosis and leaflet were found in Hainan province, a tropical island of China. The total DNA of the plant samples were extracted using 0.10 g fresh plant leaves using CTAB method. PCR reactions were performed using primers R16mF2/R16mR1 and secAfor1/secArev3 specific for phytoplasma 16S rRNA and secA gene fragments. The target productions of the two gene fragments of phytoplasma were detected in the DNA from three symptomatic plant samples whereas not in the DNA from the symptomless plant samples. The two gene fragments of the DNA extracted from the symptomatic plant samples were all identical, with the length of 1324 bp 16S rRNA and 760 bp secA gene sequence fragments, putatively encoding 253 (secA) amino acids sequence. The phytoplasma strain was named as Emilia sonchifolia witches'-broom (EsWB) phytoplasma, EsWB-hnda strain. To our knowledge, this was the first report that Emilia sonchifolia witches'-broom disease was caused by the phytoplasma belonging to16SrII-V subgroup in Hainan island of China, with close relationship to 16SrII peanut witches'-broom group phytoplasma strains infecting the plants like peanut, Desmodium ovalifolium and cleome from the same island of China and cassava from Viet Nam.In November 2020, leaf sheath on maize (Zea mays) was detected in southeastern Jiangsu (Nantong municipality; 120.54° E, 31.58° N) in China. Physiologically mature plants, 13 weeks of cultivation (at the harvest stage), exhibited red-brown lesions in stem and leaves, and dried-up stem (Figure 1). The symptoms were observed on approximately 95% of the maize plants in a 0.8 ha maize field surrounded by old sorghum fields and the crop yield was decreased by 70-85% with respect previous years, when no disease symptoms were detected. Small pieces, approximately 0.3 cm2 in size, of symptomatic tissue were surface sterilized in 1.5% NaOCl for 1 min, and washed twice with sterile ddH2O. The pathogen was isolated (one isolate was obtained) and cultured on PDA medium, containing chloramphenicol (50 µg/mL), under darkness at 26 ºC for 3 days. Amplification of internal transcribed spacer (ITS), large subunit (LSU), actin (ACT) and β-tubulin (TUB2) genes was performed using ITS1/ITS4, LR0R/LR7, ACT512F/ACT783R and T1/Bt2bty of this pathogen. The pathogen was also reported to cause leaf spot on maize in Brazil in 2004 (Do Amaral et al. 2004); however, this is the first report of E. sorghinum causing leaf sheath and leaf spot on maize in China. Maize an important agricultural crop in China with more than 168 million tons produced in 2019. The observed yield loss and disease incidence of the isolated strain suggest that E. sorghinum may be a threat to maize production in China.In Aug 2019, approximately 10% of mung bean plants at the experimental farm of the Jiangsu Academy of Agricultural Science (32.03 N; 118.88 E) showed symptoms of stunting and wilting. Brown and water-soaked stem lesions were often observed at the base of the diseased plants. In severe cases, the plants collapsed and cumulous aerial mycelia were visible on the basal stem surface (Figure S1 A). To identify the causal agent, a total of 20 tissue fragments (5 mm long) were excised from roots and basal stems of five symptomatic plants. The fragments were surface sterilized in 2% sodium hypochlorite solution then plated on 2.5% potato dextrose agar (PDA) plates containing 10 μg/mL pimaricin, 100 μg/mL ampicillin, 10 μg/mL rifampicin, and 10 μg/mL pentachloronitrobenzene (PARP; Beckerman et al. 2017). After 3-4 days incubation at 25oC in dark, 14 colonies with white and cumulous mycelia grew from the tissue pieces (named as JS19-1 to JS19-14). JS19-1 and JS19-2 were purified by hyphal tipping, then grown on PDA medieated twice. P. aphanidermatum causes seed rot, pre- and postemergence damping-off, or stem/root rot of a wide range of industrial crops and vegetables (Liu et al, 2018). To our knowledge, this is the first report of P. aphanidermatum causing disease on mung bean in China. Since Phytophthora vignae (Sun et al, 2020) and P. myriotylum (Yan et al, 2021) have been reported causing mung bean root rot, integrated disease management should be adopted to reduce damage.Buckwheat (Fagopyrum esculentum), belonging to the Polygonaceae family, is one of the most important "functional food" crops in China. In fall 2020, buckwheat plants grown in field exhibiting stem canker symptoms were found in Tongxin county, Ningxia province, China. Symptoms included stem canker, dieback and extensive vascular discoloration. Cankers were bleached, silvery-white to dark gray, slightly sunken, oval to linear with slightly tapered tips, pycnidia formation was also observed within the cankers. Disease incidence was approximately 30% and moderate to high severity across the field. Symptomatic tissues were cut into 1-2 cm pieces, surface sterilized (75% ethanol for 30 s and 0.1% NaClO for 2 min) and washed four times with sterile distilled water, dried in sterile filter paper for 3 times, and placed on potato dextrose agar (PDA) at 25 ℃. Fluffy mycelium was visible for all isolates after 48 h of incubation. Twenty-five single isolates were hyphal-tip purified on PDA. Six representative isolates werence of this disease may represent a significant impact for buckwheat production because this crop is the major agricultural commodity in some parts of China. More studies are needed to understand the epidemiology of this disease and foster disease management programs in China.Codonopsis pilosula Franch., also known as Dangshen, is an important medicinal plant in China. It is widely cultivated for a major income of local farmers in Dingxi, Gansu Province. Its dried roots have the effects of supplementing vital energy, nourishing spleen and lung, enhancing organic immunity, helping depressurization, and improving microcirculation, etc., for humans. In June to October, 2018-2020, root rot disease was observed on C. pilosula with incidences up to 20% in the Dingxi region. We collected ten diseased and healthy plants from Dingxi (35°06'N, 104°29'E, 2206 m a.s.l.) in October 2019. The rotting root tissues were sterilized with 70% ethanol for 30 s and 3% NaOCl for 5 min and placed on potato dextrose agar (PDA) plates incubated at 25℃to isolate the pathogen (Shang et al. 2014). https://www.selleckchem.com/products/deutenzalutamide.html From the similar fungal cultures isolated after 7 days on PGA, isolate B17 was purified for morphological and molecular characterization. Its colony appeared light purple and produced long aerial hyphae. Slightly curved macroconidia (12.
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